Versatile mobile platform

[0001] This application claims the benefit of Provisional Patent Application Nos. 62/746,688, filed Oct. 17, 2018, 62/740,573, filed Oct. 3, 2018, 62/740,580, filed Oct. 3, 2018, 62/702,148, filed Jul. 23, 2018, 62/699,101, filed Jul. 17, 2018, 62/720,478, filed Aug. 21, 2018, 62/720,521, filed Aug. 21, 2018, 62/735,137, filed Sep. 23, 2018, 62/740,558, filed Oct. 3, 2018, 62/696,723, filed Jul. 11, 2018, 62/736,676, filed Sep. 26, 2018, 62/699,367, filed Jul. 17, 2018, 62/699,582, filed Jul. 17, 2018, 62/729,015, filed Sep. 10, 2018, 62/730,675, filed Sep. 13, 2018, 62/736,239, filed Sep. 25, 2018, 62/737,270, filed Sep. 27, 2018, 62/739,738, filed Oct. 1, 2018, 62/748,943, filed Oct. 22, 2018, 62/756,896, filed Nov. 7, 2018, 62/772,026, filed Nov. 27, 2018, 62/774,420, filed Dec. 3, 2018, 62/748,513, filed Oct. 21, 2018, 62/748,921, filed Oct. 22, 2018, 62/731,740, filed Sep. 14, 2018, 62/760,267, Nov. 13, 2018, and 62/737,576, filed Sep. 27, 2018, each of which is hereby incorporated by reference.

[0002] In this patent, certain U.S. patents, U.S. patent applications, or other materials (e.g., articles) have been incorporated by reference. Specifically, U.S. Patent Application Nos. 62/746,688, 62/740,573, 62/740,580, 62/702,148, 62/699,101, 62/720,478, 62/720,521, 62/735,137, 62/740,558, 62/696,723, 62/736,676, 62/699,367, 62/699,582, 62/729,015, 62/730,675, 62/736,239, 62/737,270, 62/739,738, 62/748,943, 62/756,896, 62/772,026, 62/774,420, 15/272,752, 15/949,708, 16/048,179, 16/048,185, 16/163,541, 16/163,562, 16/163,508, 16/185,000, 16/109,617, 16/051,328, 15/449,660, 16/041,286, 15/406,890, 14/673,633, 16/163,530, 16/297,508, 15/614,284, 15/955,480, 15/425,130, 15/955,344, 15/243,783, 15/954,335, 15/954,410, 15/257,798, 15/674,310, 15/224,442, 15/683,255, 15/048,827, 14/817,952, 15/619,449, 16/198,393, 15/981,643, 15/986,670, 15/447,450, 15/447,623, 15/951,096, 16/270,489, 16/130,880, 14/948,620, 14/922,143, 15/878,228, 15/924,176, 16/024,263, 16/203,385, 15/647,472, 15/462,839, 16/239,410, 16/230,805, 16/129,757, 16/245,998, 16/353,019, 15/447,122, 16/393,921, 16/440,904, 15/673,176, 16/058,026, 14/970,791, 16/375,968, 15/432,722, 16/238,314, 14/941,385, 16/279,699, 16/041,470, 15/006,434, 14/850,219, 15/177,259, 15/792,169, 14/673,656, 15/676,902, 15/410,624, and 16/504,012 are hereby incorporated by reference. The text of such U.S. patents, U.S. patent applications, and other materials is, however, only incorporated by reference to the extent that no conflict exists between such material and the statements and drawings set forth herein. In the event of such conflict, the text of the present document governs, and terms in this document should not be given a narrower reading in virtue of the way in which those terms are used in other materials incorporated by reference.

[0003] The disclosure relates to semi-autonomous and autonomous robotic devices.

[0004] Autonomous or semi-autonomous robots are increasingly used within consumer homes and commercial establishments. In several instances, robots are desirable for the convenience they provide to a user. For example, autonomous robots may be used to autonomously execute actions such as sweeping, mopping, dusting, scrubbing, power washing, transportation, towing, snow plowing, salt distribution, mining, surgery, delivery, painting, and other actions traditionally executed by humans themselves or human-operated machines. Autonomous robots may efficiently execute such actions using a map of an environment generated by the robot for navigation and localization of the robot. The map may be further used to optimize execution of actions by dividing the environment into subareas and choosing an optimal navigation path. With robots being increasingly used for multiple functions, a VMP robot that may be customized for multiple different applications may be advantageous.

[0005] The following presents a simplified summary of some embodiments of the techniques described herein in order to provide a basic understanding of the invention. This summary is not an extensive overview of the invention. It is not intended to identify key/critical elements of the invention or to delineate the scope of the invention. Its sole purpose is to present some embodiments of the invention in a simplified form as a prelude to the more detailed description that is presented below.

[0006] Provided is a wheeled device, including: a chassis; a set of wheels coupled to the chassis; one or more electric motors for rotating the set of wheels; a plurality of modules for performing work coupled to the chassis; a processor electronically coupled to a plurality of sensors, including at least one exteroceptive sensor and at least one proprioceptive sensor; and a tangible, non-transitory, machine readable medium storing instructions that when executed by the processor effectuates operations including: capturing, with the at least one exteroceptive sensor, readings of the environment and capturing, with the at least one proprioceptive sensor, readings indicative of displacement of the wheeled device; estimating, with the processor using an ensemble of simulated positions of possible new locations of the wheeled device, the readings of the environment, and the readings indicative of displacement, a corrected position of the wheeled device to replace a last known position of the wheeled device, wherein: the processor loses or reduces knowledge of a current position of the wheeled device in relation to a global frame of reference of the environment of the wheeled device due to drift or slippage not reliably recordable by the at least one proprioceptive sensor when the wheeled device moves along a path from the last known position to a new intended position while performing a first task; and the processor estimates each simulated position by adding the readings captured by the at least one proprioceptive sensor to the last known position and at least one possible variation of error in the readings indicative of displacement of the wheeled device captured with the at least one proprioceptive sensor; determining, by the processor using the readings of the exteroceptive sensor, a most feasible position of the wheeled device as the corrected position; and transmitting, by the processor, status information of one or more tasks performed by the wheeled device to an external processor, wherein the status information initiates a second wheeled device to perform a second task.

[0007] Provided is a tangible, non-transitory, machine readable medium storing instructions that when executed by a processor effectuates operations including: capturing, with at least one exteroceptive sensor, readings of an environment and capturing, with at least one proprioceptive sensor, readings indicative of displacement of a wheeled device; estimating, with the processor using an ensemble of simulated positions of possible new locations of the wheeled device, the readings of the environment, and the readings indicative of displacement, a corrected position of the wheeled device to replace a last known position of the wheeled device, wherein: the processor loses or reduces knowledge of a current position of the wheeled device in relation to a global frame of reference of the environment of the wheeled device due to drift or slippage not reliably recordable by the at least one proprioceptive sensor when the wheeled device moves along a path from the last known position to a new intended position while performing a first task; and, the processor estimates each simulated position by adding the readings captured by the at least one proprioceptive sensor to the last known position and at least one possible variation of error in the readings indicative of displacement of the wheeled device captured with the at least one proprioceptive sensor; determining, by the processor using the readings of the exteroceptive sensor, a most feasible position of the wheeled device as the corrected position; and, transmitting, by the processor, status information of tasks performed by the wheeled device to an external processor, wherein the status information initiates a second wheeled device to perform a second task.

[0253] The present techniques will now be described in detail with reference to a few embodiments thereof as illustrated in the accompanying drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding. It will be apparent, however, to one skilled in the art, that the present techniques may be practiced without some or all of these specific details. In other instances, well known process steps and/or structures have not been described in detail in order to not unnecessarily obscure the present techniques. Further, it should be emphasized that several inventive techniques are described, and embodiments are not limited to systems implanting all of those techniques, as various cost and engineering trade-offs may warrant systems that only afford a subset of the benefits described herein or that will be apparent to one of ordinary skill in the art.

[0254] Some embodiments include a Versatile Mobile Platform robot (VMP robot), an autonomous robotic device, customizable to provide a variety of different functions. For example, the VMP robot may be customized to function as a smart bin for refuse and recyclables, an autonomous indoor trash bin, a robotic mop, a robotic transportation device for transporting other robotic devices, a luggage carrying robotic device, a robotic commercial cleaner, a robotic transportation device for passenger pods, a robotic towing device, a food delivering robotic device, a car washing robotic device, a robotic vacuum, etc. In some embodiments, the VMP robot includes, but is not limited to, wheels, motors, a power source, internal and external sensors, one or more processors, one or more controllers, mapping capabilities including area division, localization capabilities, and path planning capabilities. In some embodiments, the VMP robot includes software that may be customized depending on the intended function of the VMP robot. In some embodiments, the wheels are mecanum wheels and allow movement in any direction. In some embodiments, the VMP robot further includes a wheel suspension system. In some embodiments, sensors include one or more of, but are not limited to, sonar sensors, light detection and ranging (LIDAR) sensors, laser detection and ranging (LADAR) sensors, cameras, stereo and structured light sensors, time-of-flight sensors, TSSP sensors, infrared (IR) sensors, tactile sensors, ultrasonic sensors, depth sensing cameras, optical flow sensors, IR illuminator, light transmitters and receivers, odometry sensors, optical encoders, inertial measurement units (IMU), global positioning systems (GPS), structure from motion sensors, and gyroscopes. In some embodiments, the VMP robot further includes one or more electrical ports (e.g., electrical socket, mobile device charging port, home assistant charging port, etc.) that are supplied electricity using a separate or the same rechargeable battery as the main rechargeable battery of the VMP robot or solar energy. The VMP robot may further include network capabilities such as Wi-Fi™ or Bluetooth capability and USB ports. Other robotic devices with other configurations may also be used.

[0255] In some embodiments, the VMP robot further includes an operating system and an operating system interface. In some embodiments, the operating system interface is displayed on a touch screen of the VMP robot or any structure coupled thereto. In some embodiments, different types of hardware may be installed and detected by the operating system such that the VMP robot may be customized based on the intended function. In some embodiments, wherein the installed hardware is not detected by the operating system, the operating system interface displays a message to a user requesting the driver file of the hardware. In some embodiments, the VMP robot includes expansion slots for different types of hardware, such as imaging sensors, movement sensors, RAM, hard drives, controllers, etc., such that different types of hardware may be added and removed as needed. For example, a VMP robot customized with a warming oven and cooler for delivering take-out food (and any additional structure coupled thereto, such as the warming over for example) may be equipped with high-resolution sensors and additional RAM as the processor must recognize and respond to street signs (e.g., speed limits, stop signs, and stop lights) and environmental conditions (e.g., speed bumps or potholes) while travelling at a relatively quick speed. In another example, a VMP robot customized with a trash bin may navigate from a back of a house to a front of the house for refuse pickup. In this instance, the VMP robot (and any additional structure coupled thereto, such as the trash bin for example) may only be equipped with low-resolution sensors as high-speed travel is not required and navigation is limited to moving from the back of the house to the front of the house. In a further example, a VMP robot may be customized with a loading and unloading mechanism for loading and unloading a passenger pod used by the VMP robot to transport persons from a home to an office. Since the functionality involves transportation of humans, the VMP robot may be equipped with high resolution sensors to provide the highest safety standards. In some embodiments, hardware is installed on an as need basis depending on, for example, the transported item, the payload, and the intended function of the customized VMP robot. In some embodiments, the hardware and operating system of the VMP robot may be calibrated or recalibrated for their intended function. For example, if a VMP robot was not initially calibrated for transportation of shipping containers from a shipyard to a train yard, new hardware (e.g., cameras, sensors, memory, processors, hard drives, etc.) and mechanical structures (e.g., tow bar, extended platform, etc.) required in transporting shipping containers may be added. In some embodiments, additional software may be used to meet functionality requirements of the VMP robot.

[0256] In some embodiments, the VMP robot is customized based on, for example, the transported item, the payload, or the intended functionality of the VMP robot. For example, a VMP robot may be customized to further include a platform of a particular size for transporting items, a loading and unloading mechanism that allows for transportation of passenger pods, a shovel for plowing, a wheel lift for towing vehicles, robotic arms for garbage pickup, a forklift for lifting vehicles, etc. In some embodiments, the VMP robot may be customized to include clasps, magnets, straps, cords or other securing mechanisms to secure items transported to the VMP robot.

[0257] In some embodiments, the VMP robot includes speech recognition technology. For example, the VMP robot may include acoustic sensors to record voice commands that the processor may process and based on the result actuate the VMP robot to execute a particular action. Examples of voice activated robots are provided in U.S. Patent Application Nos. 62/699,367 and 62/699,582, the entire contents of which are hereby incorporated by reference. In some embodiments, the VMP robot may include speakers and the processor may respond or communicate with an operator using speech technology. For example, a user may verbally state a keyword which may activate a VMP robot customized to function as smart bin for refuse. Once activated, the user may provide verbal commands to the smart bin, such as refuse collection which triggers the smart bin to autonomously navigate to the refuse collection site. In another example, the user may provide verbal commands to a VMP robot customized to function as a mobile robotic cleaner including a type of cleaning, a cleaning location, a brush rpm, a suctioning power, a type of liquid for mopping, deep cleaning or light surface cleaning, a type of work surface for cleaning, and the like. In some embodiments, the VMP robot may use voice recognition software. The voice recognition may be able to understand sounds, text, commands, and the like. Further, the voice recognition software may use voice tone software for authenticating a user. In some embodiments, an application of a communication device paired with the processor of the VMP robot may be used by the user to provide commands, as described further below.

[0258] In some embodiments, the VMP robot may connect with other electronic devices, including static devices and mobile devices. In some embodiments, a user may provide commands to the VMP robot and the processor of the VMP robot may process the commands, and if applicable relay the commands to the paired electronic devices to which the commands are directed. In some embodiments, the commands are relayed between electronic devices using radio frequency (RF), Bluetooth, Wi-Fi, or other wireless transmission method. For example, a user may command a VMP robot customized as a smart bin to empty refuse and recyclables within and outside of the house. The processor of the smart bin may communicate with one or more indoor robotic trash bins within the house and command them to navigate to and empty their refuse into the smart bin prior to the smart bin navigating to a refuse pickup location, and may communicate with a smart recycling bin to command it to navigate to a recycling pick up location. While the smart bin does not have the ability to empty refuse from within the house or empty recyclables it may provide instructions to the one or more indoor robotic trash bins and smart recycling bin to which it is connect with. In another example, a user may provide instruction to wash the laundry to a VMP robot customized to function as an indoor robotic trash bin. Although the indoor robotic trash bin does not have the ability to wash the laundry, the processor of the indoor robotic trash bin may communicate the instructions to a robotic laundry hamper and robotic washing machine to which it is connected to. In one example, a VMP robot customized as a vacuum cleaner communicates with a robotic mop and notifies the robotic mop after finishing vacuuming in an area, triggering the robotic mop to mop the area. Or the vacuum cleaner communicates with the robotic mop to provide an area it will be cleaning and a movement path and the robotic mop follows immediately behind the robotic vacuum along the same path, such that a location is mopped immediately after being vacuumed. In some cases, the robotic mop follows the robotic vacuum cleaner by detecting signal transmitted from the robotic vacuum cleaner. In another example, one robot may move along a path while mopping the floors, while another robot follows immediately behind along the same path while polishing the floors. In some cases, more than two robots may collaborate in completing complementary tasks. For example, a robotic sweeper may move along a path while sweeping, a robotic mop may follow along the same path immediately behind the robotic sweeper and mop the floors, and a robotic floor polisher may follow along the same path immediately behind the robotic mop while polishing the floors. In other examples, different complementary tasks may be executed by different types of robotic devices. For example, an outdoor robotic blower may follow along an edge of a street while blowing debris into piles for easy collection, while an outdoor robotic sweeper may follow along the same path immediately behind to collect any debris the robotic blower may have missed. An example of an outdoor debris cleaning robot is described in U.S. Patent Application No. 62/737,270, the entire contents of which is hereby incorporated by reference. The outdoor debris cleaning robot may employ similar methods and techniques described herein. In some embodiments, the processor of the leader robot may determine an amount of delay between itself and the robot following immediately behind. In another instance, the processor of the VMP robot may connect with a home and may actuate different functions or provide instructions to devices controlling actuation of different functions within a home based on instructions provided to the VMP robot by a user. For example, a user may instruct the VMP robot to turn a shower ten minutes prior to their alarm sounding, and the VMP robot connected to both the alarm and the shower may provide required instructions to the shower, or a user may request the VMP robot to water the lawn, and the VMP robot connected to the sprinklers actuates the sprinklers to turn on, or a user may ask the VMP robot to dim, turn off, or turn on, lights or a fan in a room, and the VMP robot connected with the lights and fan may actuate or instruct the lights or fan to dim, turn off, or turn on. The above are provided as examples, however many possibilities are available. In some embodiments, the processor of the VMP robot may interact with the user by asking a question to which the VMP robot may respond (e.g., what is the weather outside?), instructing the VMP robot to provide particular information (e.g., provide a joke, play music or a particular song, etc.), playing a game, and many other ways. In some embodiments, the processor of the VMP robot uses information stored internally to provide a response to an interaction provided by a user. In some embodiments, the VMP robot connects with the internet and searches the internet to provide a response to an interaction provided by a user. In some embodiments, the VMP robot may follow a user around the environment when not executing an intended function (e.g., when not cleaning for a VMP robot customized as a surface cleaning robot) such that the user may relay commands from any location within the environment. In some embodiments, the user remotely provides instructions to the processor of the VMP robot using an application of a communication device paired with the processor. In some embodiments, after remaining idle in a position adjacent to the user, the processor of the VMP robot may alert the user (e.g., via lights or a noise) when the user moves to avoid the user injuring themselves.

[0259] In some embodiments, the processor of the VMP robot may be pre-paired with particular electronic devices. In some embodiments, the processor of the VMP robot may search for one or more electronic devices with which it may establish a connection. In some embodiments, a user may be notified if the processor is unable to establish a connected with a particular electronic device. In some embodiments, a user is notified when a task or action is completed or incomplete. In some embodiments, information is provided to the user through an application of a communication device paired with the processor of the VMP robot, a graphical user interface of the VMP robot, audio, etc. In some embodiments, the processor of VMP robot may understand speech of a user, formulate sentences that a user may understand, and communicate using a computer simulated voice.

[0260] FIG. 1A illustrates an example of a small VMP robot including LIDAR 100, sensor window 101 behind which sensors are positioned, sensors 102 (e.g., camera, laser emitter) and bumper 103. FIG. 1B illustrates internal components of the small VMP robot including LIDAR 100, sensors 102 of sensor array 104, PCB 105, wheels including suspension 106, and battery 107. The VMP robot may be customized (e.g., by customizing software, hardware, and structure) to provide various different functions. In some embodiments, the same internal components and some base components are maintained (e.g., sensors, PCB, drive wheels, etc.) for each VMP robot customization, while additional electronic components and structures may be added depending on the intended function and desired design of the robot. Furthermore, the shell of each VMP robot customization may be modified. For example, FIG. 2A illustrates the VMP robot customized to function as an indoor trash bin including LIDAR window 200, sensor windows 201 behind which sensors are positioned and sensors 202 (e.g., camera, laser emitter, etc.). FIG. 2B illustrates internal components of the indoor trash bin including LIDAR 200, sensors 202 of sensor arrays 203, PCB 204, wheels including suspension 205, and battery 206. The internal trash bin includes similar components as the VMP robot illustrates in FIGS. 1A and 1B, however the body of the VMP robot was increased in side to accommodate the trash bin 207 by adding additional castor wheels 208. The trash bin 207 may or may not include a lid. In some cases, the lid may autonomously open upon detecting a person approaching to dispose refuse or may be opened by a user using voice command or by activating a button. In some instance, the trash bin may be replaced by a compost bin or recycling bin or other type of bin. In some cases, a user chooses a designated location of an indoor trash bin in a map of the environment using an application of a communication device. In some cases, the processor generates a map of the environment and localizes using mapping and localization methods described herein. In some cases, the indoor trash bin includes sensors that collect data may be used by the processor to detect a fill level of the trash bin. In some instances, the indoor trash bin notifies a user that it is full using lights, a noise, or displaying a message on a local user interface or an application of a communication device paired with the VMP robot. In some cases, the trash bin autonomously navigates to a location where refuse is emptied (e.g., garage) when full or when instructed by a user. In some cases, the indoor trash bin may autonomously empty the refuse when full at a location where refuse is emptied and return back to a particular location. In some instances, a user may instruct an indoor trash bin to navigate to a particular location to facilitate throwing refuse away. For example, the indoor trash bin (or compost bin) may navigate to each person sitting at a dining table after dinner, such that each person may easily empty their remaining food into the trash bin. In some cases, the indoor trash bin autonomously navigates to areas with high user activity. For example, if there is a high level of activity detected in a living the indoor trash bin may autonomously navigate to the living room, then may later retreat to a designated location. In some instances, such as in large commercial offices, a control system may manage multiple indoor trash bins and may instruct a full indoor trash bin to navigate to a location for emptying refuse and an empty (or with minimal refuse) indoor trash bin to replace the location of the full indoor trash bin. In other instances, processors of two or more indoor trash bins collaborate to coordinate the replacement of a full indoor trash bin when it departs to empty its refuse. Collaboration methods such as those described herein may be used.

[0261] FIG. 3 illustrates the VMP robot customized to function as a multimedia device including a projector 300 for projecting videos and a holder for a communication device, such as a tablet 301 that may display a video or play music through speakers of the multimedia device or the communication device. In some instances, the multimedia device may autonomously follow a user around an environment, playing a desired type of music. In some instances, the multimedia device may connect with other speakers within the environment and play the music through those speakers. In some cases, the processor of the multimedia device learns the type of music a user likes and autonomously chooses the music to play. In some cases, the music is streamed from the communication device or the internet or is stored in a memory of the multimedia device. In some instances, a user may provide voice commands to the multimedia device, such as “play music” or “play country music” or “play movie”. In some instances, the processor of the multimedia device learns optimal positioning within an environment or subarea of the environment for playing music through its speakers or for projecting a video. In some instances, the multimedia device may project a video that is playing on the communication device or may stream a video directly from the internet or that is stored in the internal memory. In some instances, the projector projects a light pattern for decorative reasons. In some instances, the light pattern is choreographed to the music. An example of a multimedia robot is described in U.S. Patent Application No. 62/772,026, the entire contents of which is hereby incorporated by reference. FIG. 4A illustrates a VMP robot customized to function as a robotic vacuum including sensor windows 400 behind which sensors are positioned, sensors 401 (e.g., camera, laser emitter, TOF sensor, etc.), user interface 402, and bumper 403. FIG. 4B illustrates internal components of the robotic vacuum including sensors 401 of sensor array 404, PCB 405, wheels including suspension 406, battery 407, and floor sensor 408. FIG. 5A illustrates a VMP robot customized to function as a robotic steam mop including sensor window 500 behind which sensors are positioned, sensors 501 (e.g., camera, laser emitter, TOF sensor, etc.), user interface 502, and bumper 503. FIG. 5B illustrates a bottom perspective view of the steam mop with mopping pad 504, side brush attachment points 505, and sensors 501 (e.g., floor sensor, edge sensor, etc.). Internal components of the robotic steam mop may be similar to those shown in FIG. 5B. Processors of robotic surface cleaners, the robotic vacuum and robotic steam mop provided in these particular examples, may map their surroundings and localize themselves within the map using mapping and localization methods described herein. In some cases, the robotic surface cleaner rotates 360 degrees in one or more positions to scan an area and generate a map from the scans. In other instances, the robotic surface cleaner explores an area while mapping, and in some cases, perform work while exploring and mapping. In some instances, the processor divides the surroundings into subareas and orders the different subareas for cleaning using area division methods described herein. In some cases, the processor determines an optimal cleaning path based on various factors such as, minimal repeat coverage, coverage time, total coverage, travel distance, etc. using path planning methods described herein. In some instances, both the robotic vacuum and the robotic steam mop collaborate, wherein the robotic vacuum completes coverage of an area, and once complete notifies the robotic steam mop thereby triggering the robotic steam mop to mop the area. In some instance, the robotic steam mop follows directly behind the robotic vacuum, the two sharing the exact same movement path such that a location is mopped immediately after the location is vacuumed. In other cases, the robotic vacuum and robotic steam mop may be replaced by other types of surface cleaners, such as robotic mop, robotic UV sterilizer, robotic floor polisher, robotic floor scrubber, etc. In some instances, a single robotic surface cleaner includes two or more cleaning tools. For example, the vacuum may be in a front portion and the steam mop in a rear portion of the robotic surface cleaner, such that during operation a location is vacuumed prior to being mopped. In some cases, cleaning tools may be activated or deactivated during operation such that a user may choose the type of cleaning.

[0262] FIG. 6 illustrates the VMP robot customized to function as a robotic mobile router including similar components as the robots described above with the addition of a router 600. In instances, the robotic mobile router may be used for rebroadcasting a Wi-Fi signal. In some instances, the robotic mobile router may be stored in at least one location such as at a base station and may be called upon by a user when Wi-Fi servicing is required. In some cases, the robotic mobile router may broadcast a Wi-Fi signal from a predetermined location on a recurring basis. For example, a user may select that a robotic mobile router broadcast a Wi-Fi signal from a same location on a recurring basis. In some instances, the processor of the robotic mobile router may use historical data and machine learning techniques for determining an optimal location from which to broadcast a Wi-Fi signal from using similar methods as those described herein. In some instance, the processor may measure the strength of the Wi-Fi signal rebroadcasted and the strength of the Wi-Fi signal of connected electronic devices when located in different locations. In some instances, the processor may detect activity level or the location of connected electronic devices in an environment and position the robotic mobile router closer to areas which high activity level or highest density of connected electronic devices. In some cases, a schedule may be set for a robotic mobile router to provide Wi-Fi signal broadcasting services. For example, a schedule may be set for a robotic mobile router to navigate to at least one predetermined signal broadcasting location at least one predetermined date and time that may or may not be recurring on a, for example, weekly or bi-weekly basis. For example, a user may arrive at a home and watch television in the living room at the same time every weeknight, and the robotic mobile router may therefore provide a Wi-Fi signal service at this location and time each night. After completion of Wi-Fi broadcasting services, the robotic mobile router may autonomously navigate back to a designated storage location such as, for example, a base station. In some cases, scheduling information for Wi-Fi signal broadcasting may be provided to the processor using an application of a communication device connected with the processor, a remote control, a user interface on the robotic mobile router, or another type of device that may communicate with the processor. In some instances, the robotic mobile router will act as a Wi-Fi repeater, taking a Wi-Fi signal from, for example, a stationary router, or a stationary router and modem and rebroadcasting the signal to boost the Wi-Fi signal in an area with a non-existent or weak Wi-Fi signal strength. In some cases, the stationary router or modem may be, for example, a base station of the robotic mobile router. For example, the base station may act as a main modem and router for internet connection. In some instances, the base station may act as a storage location and/or charging station for the robotic mobile router. In some cases, the base station may be a stationary router that rebroadcasts a signal from a main router or main router/modem. In some cases, the processor of the robotic mobile router determines the most optimal location for boosting a signal in an environment based on factors such as, location of one or more users, electronic devices connected with the router, the main router, other Wi-Fi repeating devices, electronic devices connected and currently using the most data, and the like. In some instances, the robotic mobile router follows a user around an environment to constantly provide strong Wi-Fi signal. The robotic mobile router may be paired with a communication device of the user such as, for example, a mobile phone, smartwatch, or other device, and as the user traverses the environment, the processor may track the location of the device to follow the user. Alternatively, or in addition, a remote control or remote key held by the user may be paired with the mobile robotic device, and as the user traverse the environment, the mobile robotic device will track the location of the remote and follow. Other alternative embodiments are possible and are not intended to be restricted to these examples. In some instances, the robotic mobile router may be paired with an application of a communications device or a remote control. The user may use the application or remote control to request the robotic mobile router navigate to a particular location in a map. Alternatively, a user may capture an image that is transmitted to the processor for processing to determine the location captured in the image, to which the robotic mobile router may navigate. In some instances, the user request signal boosting and the processor determines the location of the user and navigates to the user. In some instances, the processor detects when one or more electronic devices are connected to the Wi-Fi and autonomously navigates to a location that provides optimal signal strength for the one or more electronic devices. For example, the processor may detect a smart phone and smart TV in a living room connected to the Wi-Fi and navigate to a location in the living to provide optimal signal strength. In some instances, the processor continuously monitors the signal strength of electronic devices connected to the Wi-Fi and adjusts its location in real-time to provide optimal signal strength to the devices. In some instances, the processor only considers electronic devices actively being used. In some instances, the processor determines optimal locations for providing strong signal strength using reinforcement learning methods or machine learning methods such as those described herein. In some instances, the processor uses historical data such as scheduling data, days and times electronic devices are connected and actively used, types of electronic devices connected and amount of data used by each electronic device, locations of electronic devices connected when actively used, and the like in determining optimal locations for providing strong signal strength to electronic devices. For example, the processor may detect a smart TV actively used in the same location at the same time on a same day, and therefore may predict that Wi-Fi signal boosting is required at the same location on the same day and at the same time. In some instances, the processor detects its location in an environment by capturing images and identifying features in the images and determines if it is located in a burdensome location, such as a middle of a hallway that may act as a tripping hazard to users. In some instances, robotic mobile router repositions itself if located in a burdensome location to a next best location or does not reposition itself unless instructed to by a user. In some instances, two or more robotic mobile routers collaborate to provide optimal Wi-Fi signal strength to connected electronic devices within an environment. For example, if a first electronic device is located in a living room while a second electronic device is located in a bedroom and neither electronic devices are receiving strong Wi-Fi signal, two robotic mobile routers may be required. The two processors may collaborate such that the first robotic mobile router may provide an optimal signal strength to electronic device A, while the second robotic mobile router provides an optimal signal strength to electronic device B. Additionally, processor of both robotic mobile routers may determine locations for the two mobile routers that allows their signal strengths to intersect in a middle area between their two locations to strong signal strength to electronic devices A and B and any electronic devices located in the middle area. In some instances, the first robotic mobile router may attempt to find an optimal location to provide strong signal strength to both electronic devices A and B. If an adequate signal strength may not be provided to both electronic devices A and B, the processor of the first robotic mobile router may communicate and collaborate with the processor of the second robotic mobile router such that both electronic devices A and B may be provided adequate signal strength. In some instances, the processor of the robotic mobile router may provide priority to one or more electronic devices based on instructions provided by a user, amount of data used, type of internet activity used. For example, the robotic mobile router may prioritize providing a strong signal strength to an electronic device with higher priority when, for example, providing two or more devices with strong signal strength simultaneously is not possible. In some instances, a status of the robotic mobile router may be displayed on the user interface of the robotic mobile router, an application of a communication device paired with the processor, a remote control, or other device paired with the processor of the robotic mobile router or may be provided using audio or visual methods. Examples of statuses and/or messages may include, but are not limited to, parked at base station, on route to Wi-Fi signal repeating location, repeating Wi-Fi signal, Wi-Fi signal strength, optimality of the Wi-Fi signal strength, parked at Wi-Fi signal repeating location, on route to base station, function delayed, stuck, collision with obstruction, damaged, and the like. In some instances, a robotic mobile router may be a static wireless internet signal booster. For example, the robotic mobile router may repeat a wireless signal from a static location, such as a base station during charging. Further details of a robotic mobile router are provided in U.S. Patent Application Nos. 62/696,723 and 62/736,676, the entire contents of which are hereby incorporated by reference.

[0263] FIG. 7 illustrates the VMP robot customized to function as a robotic mobile charger including similar internal components as the robots described above with the addition of a charging pad 700 on which electronic devices 701 may charge using inductive charging. In some instances, the robotic mobile charger may be used for charging electronic devices. In some embodiments, the robotic mobile charger may remain stationary at, for example, a charging station until a request is received by the processor. In some cases, the robotic mobile charger navigates to a requested location for charging of an electronic device. In some instances, the robotic mobile charger may provide inductive charging capability, providing the battery of an electronic device with charging power to recharge the battery by, for example, placing the electronic device on top of the robotic mobile charger, within a slot or indentation of the robotic mobile charger, and the like. For example, an electronic device capable of inductive charging (e.g., a smart phone, a smart watch, a table, or other device) may be placed on a flat charging pad positioned on a top of the robotic mobile charger for charging. In some instance, the flat charging pad includes an inductive charging plate. In some cases, the inductive charging plate is place within a slot or indentation. In some instances, the robotic mobile charger includes electrical sockets or USB ports or built-in chargers for particular devices (e.g., mobile phone, tablets, etc.). For example, the charging cable of a mobile phone may plug into the USB port of the robotic mobile charger and may receive power from a battery of the robotic mobile charger to provide to the connected mobile phone for charging. In another example, an electronic device, such as a laptop, may plug into a three-prong socket of the robotic mobile charger for electrical power. This may be useful in locations where there is a shortage of electrical sockets, such as at a conference room. In one example, a router is plugged into a socket of the robotic mobile charger and the robotic mobile charger locates itself such that the router may provide optimal Wi-Fi signal strength to users. In some instances, the processor of the robotic mobile charger may be paired with electronic devices such that it may monitor their battery levels. In some instances, the robotic mobile charger autonomously navigates to a smartphone, a smartwatch, and the like for charging of the electronic device when their battery level is below a predetermined threshold. In some cases, a user may request a robotic mobile charger to a particular location using an application of a communications device. The request may be for a particular location and at a particular date and time and in some instances, may be recurring. In some instances, robotic mobile chargers are used within a personal space or may be used in public areas. In some instances, the type of connected required may be specified (e.g., USB, iPhone charger, socket, etc.) as some robotic mobile charger may not include all types of connections. In some instances, the robotic mobile charger navigates to a docking station for charging, to a predetermined location, to complete another request, or the like after completion of a request (i.e., charging of a device). In some embodiments, the processor of the robotic mobile charger may broadcast a signal for replacement by another robotic mobile charger when a battery level of the robotic mobile charger is low or when functional problems are detected. In some cases, a control system manages two or more robotic mobile chargers and decides which requests to provide to each robotic mobile charger based on various factors, such as location of the robotic mobile charger, location of the request, type of connectors of the robotic mobile charger, battery level, etc. using control system management methods described here. In some cases, processors of robotic mobile chargers collaborate to determine which robotic mobile charger executes each request using collaborative methods such as those described here. In some cases, more than one user may use a single robotic mobile charger such that various electronic devices are charged at once. In some instances, the processor may control the level of charging power provided. For example, if there is a need for an electronic device to be powered up quickly, a higher than normal level of charging power may be provided to the electronic device. In some cases, the robotic mobile charger may travel at a faster speed if the charging request indicates that the electronic device needs to be charged quickly. In some cases, the processor of the robotic mobile charger may receive multiple requests simultaneously and may decide which request to fulfill first based on, for example, the frequency of requests from a particular user, loyalty index of users, current battery level of the electronic devices, charging rate of the electronic devices (e.g., based on historical data), power consumption required for charging each electronic device, the types of electronic devices, last charging date (e.g., based on historical data), and the like. In some instances, the processor predicts when charging service is required and autonomously provides charging service where required. For example, if a request for charging a smartphone in the master bedroom is placed every night at approximately 9:00 PM, the robotic mobile charger may autonomously arrive at the master bedroom at approximately 9:00 PM every night. In some cases, an electronic device may require urgent charging while the robotic mobile charger is providing charging to another electronic device located elsewhere. The robotic mobile device may interrupt the current charging service and fulfill the urgent charging request. In some cases, the processor prioritizes users with higher loyalty index, wherein the loyalty index of a user increases each time they charge an electronic device. In other instances, the processor prioritizes users that have used the robotic mobile charger less. In some instances, the processor priorities particular types of electronic devices. In some cases, the robotic mobile charger completely charges one electronic device (or a set of electronic devices in cases wherein multiple electronic devices are charging simultaneously) before moving on to charge another electronic device (or another set of electronic devices). Further details of a robotic mobile charger are described in U.S. Patent Application No. 62/736,239, the entire contents of which is hereby incorporated by reference.

[0264] FIG. 8 illustrates a top perspective view of a larger VMP robot 800 including casing 800, caster wheels 801, drive wheels 802, battery 803, and securing holes 803 for securing different structures to the platform depending on the intended function of the robotic device. In some embodiments, the VMP robot is customized to function as a smart bin for refuse or recyclables. In some embodiments, customizing the VMP robot to function as a smart bin includes further equipping the VMP robot with one or more of a bin receptacle, a bin including a lift handle, a lift bar and a lid that attaches to the bin receptacle, a bumper coupled to the bin receptacle, additional sensors, a manual break, and a locking mechanism for locking the bin to the VMP robot. Another example of a smart bin is described in U.S. patent application Ser. No. 16/129,757, the entire contents of which is hereby incorporated by reference. In some embodiments, the smart bin autonomously navigates from a storage location to a refuse collection site for refuse removal from the smart bin. After removal of the refuse, the smart bin autonomously navigates back to the storage location. For example, the smart bin navigates from a storage location behind a home to the end of a drive way at a particular time and date for refuse pick up by the city. After the refuse has been removed from the smart bin, the smart bin navigates back to the storage location behind the house. In some embodiments, the smart bin only navigates to the refuse collection site if the amount of refuse is above a predetermined threshold. In some embodiments, the smart bin determines the amount of refuse within the bin using a light transmitter and corresponding receiver, that are placed opposite one another in the bin at a particular height. When the receiver no longer receives the transmitted light, the processor determines that the refuse has at least reached that height within the bin. In some embodiments, the refuse container navigates to the refuse collections on a recurring basis (e.g., every other Wednesday morning). In some embodiments, the processor receives a refuse collection schedule including a location and time for refuse collection, described further below. In some embodiments, the processor of the smart bin learns a movement path from a storage location to a refuse collection site by physically wheeling the smart bin from the storage location to the refuse collection site one or more times while the processor learns the path. This method of path learning is further described below. FIG. 9A illustrates a VMP robot 900 customized as a smart bin including bin 901 with bin lid 902, bumper 903, LIDAR window 904, sensor window 905, and lid handle 906. FIG. 9B illustrates a rear perspective view of the smart bin with manual brake 907, lift handle 908 for the bin 901, sensor window 905, foot pedals 909 that control pins (not shown) used to hold the bin in place, and lift handle 910. FIG. 9C illustrates a side view of the smart bin. Different types of sensors, as described above, are positioned behind sensor windows. FIG. 9D illustrates bin 901 removed from a bin receptacle 911 of the smart bin. Bin receptacle 911 includes rails 912 and pins 913 operated by foot pedals 910. The bottom of bin 901 includes rails 914 that slide into rails 912 of bin receptacle 911 and pin holes 915 for pins 913, thereby locking bin 901 in place. In some embodiments, pins 913 are operated by a motor or by other automatic mechanical means. In some embodiments, activating a button or switch on the smart bin or audio command causes retraction and extension of pins 913. Drive wheels 916 and castor wheels 917 are also illustrated in FIG. 9D. In some embodiments, the smart bin recharges at an outdoor recharging station. In some embodiments, the charging station provides protection for the smart bin to minimize the effects of environmental conditions (e.g., weather) on the smart bin. FIG. 10A illustrates a side view of an example of a smart bin charging station including charging contacts 1000 and cover 1001 with a smart bin 1002 docked for charging. FIG. 10B illustrates a top perspective view of the smart bin charging station with solar panel 1003. In some embodiments, the smart bin recharges using solar power stored by the solar panels of the smart bin charging station. In some instances, the smart bin includes solar panels and is powered using solar energy.

[0265] In some embodiments, a larger VMP robot is used for applications requiring a larger base. FIG. 11A illustrates another example wherein a VMP robot is customized to function as a commercial floor scrubber including the commercial floor scrubber 1100 and VMP robot 1101, that fits with floor scrubber 1100 as illustrated in FIG. 11B. Floor scrubber 1100 includes LIDAR 1102 and sensor windows 1103 behind which sensors are housed. The components and wheels of VMP robot 1101 are similar to those described for the VMP robot in FIG. 8, a smaller variation of VMP robot 1101. In some cases, the commercial floor scrubber is used for cleaning areas in which high levels of debris may routinely be encountered. The commercial floor scrubber may operate in large establishments such as malls, airports, parks, restaurants, office buildings, public buildings, public transportation, arenas, sporting venues, concert venues, and the like. The commercial floor scrubber may be beneficial for cleaning locations with high foot traffic as they result in large amounts of debris accumulation due to the large volume of individuals that frequent these locations. In some instances, VMP robot 110 may direct other types of surface cleaning robots or the scrubbing tool may be exchangeable with other cleaning tools or additional cleaning tools may be added to the commercial floor scrubber. In some instances, the processor may activate and deactivate different cleaning tools or may autonomously exchange cleaning tools at a base station that, for example, stores multiple different cleaning tools. Other cleaning tools include a brush, a vacuum, an UV sterilizer, a sweeper, a mop, a steamer, a polisher, a power washer, and the like. In some instances, additional components that are required for the use of certain cleaning tools may be included. For example, a dustbin may be included when the vacuum and brush tools are used. In another example, a fluid reservoir and fluid flow mechanism may be included when the mop tool is used. In other cases, a fluid reservoir and heating element may be included when the steamer is used or a fluid reservoir and pump when the power washer tool is used or a polish dispenser when the polishing tool is used. In some instances, the cleaning tools used may depend on, for example, the type and amount of debris in the environment or a preset schedule. For example, upon observing a liquid on the driving surface, the processor may decide to use a mop to clean the driving surface. In another example, upon observing trash on the driving surface, the processor may decide to use a sweeper to cleaning the driving surface. In some cases, processors of two or more VMP robots with commercial floor scrubbers collaborated to clean the environment using collaborative methods such as those described herein. In some instances, processors divide the area to be cleaned and share areas that have been individually covered with another in an effort to avoid repeat coverage. For example, processors may collaborate and decide or one processor may decide that one commercial floor scrubber clean a first level of a mall and the other commercial floor scrubber clean a second level of a mall. In some instances, processors of VMP robots with different cleaning tools collaborate to clean the environment. For example, processors may collaborate and decide or one processor may decide that a first VMP robot with commercial mop cleans the floor of the environment while a second VMP robot with commercial polisher follow behind on the same path to polish the floors. In some cases, the environment is divided using area division methods described herein. In other instances, a central control system may autonomously manage the two or more VMP robots with commercial floor scrubbers. For example, a control system may instruct a processor of a first VMP robot with commercial floor scrubber to clean a first level of an office that is tiled and a processor of a second VMP robot with commercial vacuum to clean a second level of an office that is carpeted. In yet another instance, an operator operates the central control system. In some cases, processors of VMP robots transmit cleaning coverage information to the control system while cleaning the environment such that the control system may efficiently manage cleaning of the environment and avoid repeat coverage of areas. In some cases, processors of VMP robots transmit other information to the control system, such as battery level, status, location, movement path, etc. In some instances, settings and movement path of the VMP robot may be dependent on debris accumulation, type, and size within the environment, as described in detail below. In some instance, the VMP robot with commercial cleaning tool may observe discolored surfaces, smudges, or the like on a driving surface and may operate to remove them from the driving surface. In some cases, the processor may be provided a cleaning schedule by a user using a communication device paired with the processor or user interface of the VMP robot or by a control system. For example, a schedule may include cleaning an entire retail establishment over the course of a week with the VMP robot with commercial floor scrubber operating for two hours daily after closing. In such an example, the processor of the VMP robot may prioritize cleaning areas with a higher likelihood of debris accumulation, such as an area surrounding a cash register or changing rooms, before cleaning other areas. Furthering the example, the processor may focus on cleaning areas surrounding the cash register and changing rooms every day, while cleaning other areas with lower likelihood of debris accumulation, such as a stock room, twice a week. In some instances, the processor keeps track of areas it has cleaned during each cleaning session. In some cases, the VMP robot with commercial floor scrubber may drive at a slower speed in areas where debris is present or in areas with higher likelihood of debris accumulation to more carefully clean them. In some cases, the processor may adjust tool settings based on debris accumulation. For example, a higher impeller RPM, a higher brush RPM, a higher sweeper RPM, a higher scrubber ROM, a higher mop RPM, or a higher polisher RPM may be used in areas where there is a higher likelihood of debris accumulation. In some instances, the VMP robot with commercial floor scrubber may pass over areas with a debris accumulation level greater than a minimum predetermined threshold level multiple times during a cleaning session. In some instances, the VMP robot with commercial floor scrubber may operate in an area for a predetermined amount of time. In some cases, the VMP robot with commercial floor scrubber may be programmed to operate in area at some frequency over a period of time. For example, the VMP robot with commercial floor scrubber may be programmed to operate in areas with a high level of debris accumulation for a predetermined amount of time. In another example, the VMP robot with commercial floor scrubber may be programmed to clean a room that has a recurring high level of debris accumulation five days a week. In some cases, the processor may use machine learning based on historical data and sensor data to predict which areas need cleaning at each cleaning session. Data used in machine learning may include, but not limited to, level of debris accumulation in different areas, types of debris in different areas, areas cleaned in prior cleaning sessions, cleaning paths, obstacles in different areas, types of obstacles in different areas, types of driving surfaces operated on, scheduling information, preferences used in prior cleaning sessions, collaborations between VMP robots, types of cleaning tools used in different areas, frequency of cleaning different areas, battery efficiency, battery level, total coverage of an area, coverage time of an area, and the like information. Further details of a commercial surface cleaning robot are described in U.S. Patent Application No. 62/739,738, the entire contents of which is hereby incorporated by reference.

[0266] FIG. 12A illustrates another example of a VMP robot including a casing 1200, drive wheels 1201, castor wheels 1202, sensor windows 1203, sensors 1204, omnidirectional LIDAR 1205, battery 1206, memory 1207, processor 1208, and connector 1209, that may implement the methods and techniques described herein. FIG. 12B illustrates the VMP robot without internal components shown from a rear view. The sensors 1204 shown in FIG. 12B in the rear view of the VMP robot may include a line laser and image sensor that may be used by the processor of the VMP robot to align the robot with payloads, charging station, or other machines. In some embodiments, program code stored in the memory 1207 and executed by the processor 1208 may effectuate the operations described herein. In some embodiments, the processor 1208 of the VMP robot uses at least some of the methods and techniques described herein to, for example, generate a map, localize, determine an optimal movement path, determine optimal coverage of an area, collaborate with other VMP robots or robots to improve efficiency of executing one or more tasks, and the like. In some embodiments, connector 1209 may be used to connect different components to the VMP robot, such that it may be customized to provide a particular function. In embodiments, the same internal structure of the VMP robot may be used while the casing may be customized based on the function or desired design of the robot. For example, FIG. 13A illustrates a commercial robotic scrubber 1300 pivotally coupled to VMP robot 1301 using connector 1302. The VMP robot 1301 navigates around an environment while robotic scrubber 1300 follows for surface cleaning using cleaning tool 1303. In some instances, additional sensors are provided on the robotic scrubber 1300 that interface with VMP robot 1301 and allow the processor to observe the environment at higher heights. In some cases, cleaning tool 1303 may be exchanged for various other types of cleaning tools. In some cases, the processor of VMP robot 1301 maps a commercial establishment and localizes itself within the environment using mapping and localization methods described herein. In some instances, the processor determines an optimal cleaning path within the environment by, for example, reducing total cleaning time and total distance travelled. In some cases, the processor divides the commercial establishment into subareas and cleans each subarea one by one, finishing cleaning in one subarea before moving onto another. In some instances, an operator may create subareas, choose operations and cleaning settings for different subareas, set a schedule for the entire environment or specific subareas, choose or modify a movement path, modify the map, etc. using an application of a communication device paired with the processor or a user interface of the VMP robot 1301 or coupled robotic scrubber 1300. In some cases, processors of two or more VMP robots with coupled robotic scrubbers collaborate to clean the commercial establishment more efficiently using collaborative methods described herein. In other instances, VMP robot 1301 may connect with other objects such as a vehicle, another robot, a cart of items, a wagon, a trailer, etc. FIG. 13B illustrates commercial robotic scrubber 1300 with cleaning tool 1301 coupled to another type of VMP robot 1302 turning to direct robotic scrubber 1300 towards the right. VMP robot 1302 includes castor wheel 1303, drive wheels 1304, and LIDAR 1305. Sensor windows behind which sensors are positioned are not shown but may be included. In some instances, a larger VMP robot 1302 may be required if, for example, a smaller VMP robot does not have the capacity (e.g., required power) to direct robotic scrubber 1300. FIGS. 13A and 13B also illustrate that different VMP robots may be used interchangeably as can add on structures, such as robotic scrubber 1300. In another example, FIGS. 14A and 14B illustrate a VMP robot 1400 customized to provide car washing via a robotic arm 1401 with brush 1402 coupled to the VMP robot 1400 using a connector. In some instances, robotic arm 1401 has six degrees of freedom and is installed on top of the VMP robot 1400. In some instances, the end of robotic arm 1401 includes the rotating brush 1402 for cleaning cars. In some cases, there may be a spray nozzle near the brush 1402 to spray cleaning liquid while brush 1402 is spinning. In some embodiments, robotic arm 1401 retracts as in FIG. 14B when not in use. In some cases, the sensors of the VMP robot 1400 detect the vehicle and based on detection of the vehicle the processor moves robotic arm 1401 such that rotating brush 1402 contacts the vehicle. In some cases, rotating brush 1402 includes a tactile sensor that may be used to detect when contact is made with the body of the vehicle. In some cases, the robotic arm 1401 may be configured to clean vehicles of various heights by, for example, adding additional links to provide access to all parts of a larger vehicle. In some instances, a vehicle drives into and parks at a designated car washing area and one or more car washing VMP robots approach for cleaning the vehicle. In some cases, one or more of the VMP robots drive one or more times around the vehicle, while the processor maps the vehicle. In some instances, the processor marks area of vehicle as complete after cleaning it. In some cases, processors of two or more VMP robots collaborate to clean a vehicle by dividing areas of the vehicle to be cleaned and notifying one another of areas covered to avoid repeat coverage. In some cases, there are multiple steps for cleaning the vehicle and there may be different attachments to the robotic arm for two or more of the steps. For example, the robotic arm may alternate between a sponge for soaping the vehicle, a brush for scrubbing the vehicle, a water spray nozzle for washing down the vehicle, a cloth for wiping down the vehicle, and a polishing pad for polishing the vehicle. In some cases, different VMP robots perform each of these steps.

[0267] FIGS. 15A and 15B illustrate a front and rear perspective view of another example, with a VMP robot 1500 fitted with an air compressor 1501. FIG. 15B shows nozzle 1502 of air compressor 1501. In some instances, the VMP robot 1500 maps an area around a vehicle and autonomously connects nozzle 1502 to the tires of the vehicle to fill them with air. In some instances, the processor of the VMP robot uses features of tires to detect the tires on the vehicle and the air nozzle of the tire. For example, a camera of the VMP robot may capture images of the vehicle as the VMP robot navigates around the vehicle. The processor may use computer vision technology to detect features of tires (e.g., tread shape, color, location relative to the rest of the vehicle, etc.). In some cases, air compressor 1501 includes an air pressure sensor such that tires may autonomously be filled to a particular pressure. In some instances, a user chooses the desired air pressure using, for example, a user interface on the VMP robot or an application of a communication device paired with the processor of the air compressor VMP robot. In some cases, the processor of the VMP robot may detect the make and model of the vehicle and fill the tires to an air pressure suggested by the manufacturer for the particular make and model. In some cases, such information on suggested air tire pressure for different make and models are stored in a database in a memory of the VMP robot. In another example, FIG. 16 illustrates VMP robot 1600 customized to provide food delivery. Due to the increased height after customization of the VMP robot, main compartment 1601 may also include additional sensors 1604 that operate in conjunction with VMP robot 1600 such that the processor may observe the environment at higher heights. In some instances, a user may request food be delivered from a particular restaurant using an application of a communication device. The application of the communication device transmits the request to a control system that manages multiple food delivery robots. Based on various factors, such as current location of food delivery robots, pick up location, drop off location, battery or fuel level of food delivery robots, etc. the control system transmits the request to a processor of a particular food delivery robot. In some cases, processors of multiple food delivery robots collaborate to determine which robot executes which task. In other instances, the food delivery robot may operate a server in a restaurant. A tray 1602 for food items 1603 may therefore be included for delivery to tables of customers in cases where the food delivery robot functions as a server. In some cases, main compartment 1601 may be one or more of: a fridge, a freezer, an oven, a warming oven, a cooler, or other food preparation or maintenance equipment. For example, the food delivery robot may cook a pizza in an oven on route to a delivery destination such that is freshly cooked for the customer, a freezer may keep ice cream cold on route to a delivery destination, or a warming oven may keep cooked food warm on route to a delivery destination. For example, FIG. 17 illustrates a VMP robot 1700 customized to function as a pizza cooking and delivery robot including oven 1701 for cooking pizza 1702 on route to a delivery location such that a customer may receive a freshly cooked pizza 1702. In some cases, the food delivery robot includes more than one food preparation or maintenance equipment. Further details of a food delivery robot are described in U.S. Patent Application No. 62/729,015, the entire contents of which is hereby incorporated by reference. FIGS. 18A and 18B illustrate yet another example, wherein VMP robot 1800 is customized to function as a painting robot including a paint roller 1801 and paint tank 1802. FIGS. 18C and 18D illustrate an alternative painting robot wherein nozzles 1803 are used instead of paint roller 1801. In some cases, the robot paints streets or roofs in a city white to reduce heat in urban areas. In some cases, different paint applicators and configurations may be used. For example, a long arm with a roller may be coupled to the VMP robot for painting a ceiling. In some instances, an operator uses a communication device paired with the VMP robot to control navigation and painting. In some cases, the processor of the VMP robot maps an area and localizes itself using mapping and localization methods similar to those described herein. In some cases, a user may access the map using an application of a communication device paired with the processor, and choose areas within the map (e.g., walls, ceilings, etc.) for painting and in some cases, the color of paint for the areas selected. In some instances, processors of multiple painting robots may collaborate to more efficiently paint one or more areas using collaborative methods similar to those described herein. For example, the processors may divide an area for painting and share with one another areas that have been painted to avoid painting the same area twice. In some cases, a user may provide a particular pattern to be painted using the application of the communication device. For example, a painting robot may paint a butterfly on a wall or may paint 0.5 m long lines spaced 0.5 m apart on a road.

[0268] FIG. 19 illustrates the VMP robot customized to function as a robotic hospital bed including VMP robot 1900 and coupled hospital bed frame 1901 with mattress 1902. The mattress 1902 is angled for maximum comfort of a patient. In some cases, the patient or the processor of the VMP robot autonomously adjusts the angle of mattress 1902. In some cases, the hospital bed frame may include sensors that interface with the VMP robot 1900 to provide observation at higher height. In some cases, the processor of the VMP robot 1900 is alerted when a hospital bed is needed in a particular location. The VMP robot 1900 may navigate to an unused hospital bed, coupled to the hospital bed frame 1901 and drive the hospital bed to the particular location. In some instances, the VMP robot 1900 may already be coupled to an unused hospital bed. In other instances, the processor of the VMP robot 1900 is provided instructions to transport a patient in a hospital bed from a first location to a second location. In some cases, the processor of the VMP robot receives instructions or information from an application of a communication device paired with the processor. In some cases, an operator inputs instructions or information into the application and the application transmits the information to the processor. In some instances, the processor of the VMP robot 1900 has inventory of unused hospital beds and their locations. The processor may have further inventory of used hospital beds and their locations. The VMP robot 1900 reduces the need for hospital staff to transport hospital beds and therefore provides hospital staff with more time to attend to patients. Multiple VMP robots for transporting hospital beds may be used simultaneously. In some cases, the processors of the multiple VMP robots collaborate to determine which tasks each VMP robot is to perform. In some cases, a control system manages all VMP robots in a hospital. In some embodiments, the processors of one or more VMP robots operating in a hospital to transport hospital beds may implement the methods and techniques described herein to, for example, determine optimal movement paths within the hospital, determine optimal collaboration, generate a map, localize, etc. FIGS. 20A and 20B illustrate a VMP robot customized to function as a fertilizer dispensing robot including VMP robot 2000 and coupled fertilizer bed 2001 with dispensers 2002 that direct fertilizer 2003 as it exits the fertilizer bed 2001. In some cases, fertilizer bed 2001 may be lifted with a hydraulic arm (not shown) to increase the rate of fertilizer dispersion. In some cases, an operator may choose the how high to lift the bed or may choose a rate of fertilizer dispersion and the processor of the VMP robot 2000 may autonomously adjust how high fertilizer bed 2001 is lifted. In some embodiments dispensers 2002 include sensors that may measures the rate of fertilizer dispersion and based on the measurement the processor may increase or decrease how high fertilizer bed 2001 is lifted to achieve the desired rate of fertilizer dispersion. In some embodiments, the VMP robot 2000 with coupled fertilizer dispersion mechanism drives in a boustrophedon pattern across a field, each alternating row slightly overlapping such that fertilizer is spread in all areas of the field. In some cases, an operator may control the movement of the VMP robot with coupled fertilizer dispersion mechanism using a communication device paired with the processor of the VMP robot. In some cases, an operator selects a region of a field on which fertilizer is to be dispersed on an application of a communication device paired with the processor of VMP robot 2000 and the VMP robot 2000 covers the selected region. In some embodiments, the operator also selects the total amount of fertilizer to disperse in the region (e.g., in kg or other units) and the processor determines the rate of fertilizer dispersion based on the total amount of fertilizer and the size of the region. In some cases, fertilizer bed 2001 includes weight sensors or other sensors that detect when fertilizer is depleted. In some cases, the VMP robot 2000 navigates back to a location where additional fertilizer may be collected. In some cases, the processor notifies the operator of low levels of fertilizer via the application or a user interface of the VMP robot. Multiple VMP robots with coupled fertilizer dispensing mechanisms may collaborate using collaboration techniques described herein to reduce the amount of time required to fertilize one or more fields. FIG. 21 illustrates the VMP robot 2100 customized to function as a mobile washroom including washroom 2101 with door 2102 and toilet 2103. In some cases, VMP robot 2100 facilitates moving washroom 2101 from a first location to a second location. For example, at a large construction site the region in which workers operate may change and VMP robot 2100 moves washroom 2101 from a first region in which workers operate to a second region in which workers operate such that the washroom is within a reasonable distance from the workers. In some cases, the mobile washroom reduces the number of washrooms required at a job site as the washroom is easily moved. In some instances, VMP robot 2100 drives to a particular location for emptying the contents of the washroom. In some cases, washroom 2101 includes sensors that may be used to detect when washroom 2101 needs emptying. In some instances, VMP robot 2100 transports washroom 2101 to a first location, decouples from washroom 2101, and navigates to a second washroom, couples to the second washroom and transports it to a second location. In some instances, an operator may use an application of a communication device to choose the desired location of one or more washrooms in an environment. In some cases, a single VMP robot 2100 transports one or more washrooms to the desired one or more location. In other cases, multiple VMP robots collaborate to transport multiple washrooms to desired locations. In some instances, a control system manages mobile washrooms and may be alerted when a mobile washroom needs emptying or moving to a new location. The control system transmits an instruction to a VMP robot to transport a particular mobile washroom for emptying or to a particular location. In some cases, VMP robots are parked in a parking lot until an instruction is received, at which point the VMP robot executes the instruction, and then returns back to the parking lot and autonomously parks.

[0269] FIG. 22 illustrates the VMP robot customized to function as a mobile chair including VMP robot 2200 and coupled chair 2201. In some cases, the chair 2201 may be interchangeable with different types of chairs depending on the needs and desires of the user. In some cases, the mobile chair may be used as a replacement for a wheel chair or motorized scooter. In some cases, the chair may lower and extend such that the user may easily demount from the chair and may reach higher items. In some instances, a user directs the mobile chair using verbal commands. In other instances, a user chooses a destination using an application of a communication device paired with the processor of the VMP robot 2200. In some instances, the processor chooses an optimal movement path to the destination using path planning methods similar to those described herein. In other instances, the user directs the VMP robot 2200 using a remote control or by drawing a movement path in a map using the application of the communication device. In some instances, the application of the communication device suggests a modification to the movement path based on, for example, finding a movement path that reaches the destination in a shorter time. FIG. 23 illustrates the VMP robot customized to function as a predator robot including VMP robot 2300 and extension 2301 with sensor window 2302 behind which additional sensors are housed. The additional sensors interface with VMP robot 2300 and allow the processor to observe the environment at higher heights. In some instances, extension 2301 may be reconfigured to appear as a particular type of animal or to have a particular color that may be off putting to specific animals. In some cases, extension 2301 emits lights and sounds that may be off putting to specific animals. For example, the predator robot may act as a replacement to hounds that are used in hunting season to direct animals to a particular location. In some instances, the predator robot may be used for an opposite effect, wherein extension 2301 may be reconfigured to appear as a particular type of animal or to have a particular color that may be enticing to specific animals. In some cases, extension 2301 emits lights and sounds that may be enticing to specific animals. In some cases, a user may choose a particular type of animal using an application of a communication device paired with the processor of the VMP robot or a user interface of the VMP robot. The processor may then alter the lights and sounds used based on the animal chosen in order to chase the animal away or attract the animal closer. In some cases, the processor may identify different types of animals using computer vision technology. In some cases, the processor only emits lights and sounds upon identifying a particular type of animal. In some instances, a user may choose an area within a map of the environment that they wish the predator robot to explore in search of particular animals. FIGS. 24A and 24B illustrate the VMP robot customized to function as a robotic lawn mower including VMP robot 2400 with castor wheels 2401 and drive wheels 2402 and connecting element 2403 used to connect VMP robot 2400 with mowing component 2404. Mowing component 2404 includes wheels 2405 and blade 2406. In some instances, blade 2406 is electrically coupled with the electronics of VMP robot 2400 such that the processor of VMP robot 2400 may control the operation of blade 2406. In some instances, the blade 2406 may rotate in one direction or in both directions. In some instances, a motor is used to rotate the blade 2406. In some cases, VMP robot 2400 includes driving surface sensors, the data from which the processor may use to predict the current driving surface of the VMP robot with mower. In some instances, the processor activates blade 2406 when a grass driving surface is detected. In some cases, the processor only activates blade 2406 when the driving surface is grass. In some instances, the VMP robot 2400 includes sensors that may measure the distance to a top of a patch of grass. In some cases, the processor determines the distance between the top of the patch of grass and the blade 2406. In some instances, the blade 2406 may be programmed to only activate when the distance between the top of the grass and the blade is below a predetermined threshold or when the height of the grass is above a predetermined threshold. In some cases, the processor generates a map of a location with grass, such as a backyard, a park or a field, by stitching captured images of the location together at overlapping points, as described herein. The processor may localize during mapping and operation when a measurement of the environment is taken by comparing the measurement against a map (e.g., spatial map, Wi-Fi map, driving surface map, etc.), as described herein. In some cases, the VMP robot is controlled by a user using a remote control or application of a communication device paired with the processor of the VMP robot. In some cases, a user may choose areas to mow on a map accessed using the application of the communication device. In some cases, a schedule may be provided to the processor using the application or the processor may autonomously generate a schedule for mowing grass in a particular area. In some cases, the processor learns optimal grass cutting schedule over time based on length of the grass observed during work sessions executed over time. Learning methods are described further herein. In some cases, the processor may detect when blade 2406 is stuck or stalled using sensor data, such as the amount of current drawn by the motor of the blade 2406, wherein a sudden increase in current may indicate entanglement of an object. In some cases, processors of multiple VMP robots with mowers collaborate to mow grass in a shorter period of time using methods such as those described herein. For example, processors divide an area to be mowed and share areas covered such that repeat coverage of locations may be avoided. In some embodiments, multiple users may share a single VMP robot with mower. For example, neighbors of a street may share the VMP robot with mower. In some cases, a control system manages operation of multiple VMP robots with mowers, instructing processors of the multiple mowers on the areas to mow and when. For example, a control system manages mowing of city parks and sports fields, instructing VMP robots with mowers to mow an entire or a portion of city parks and sports fields. Processors share their sensor data with the control system such that the control system may learn optimal mowing schedule of different areas. In some cases, VMP robots move in a boustrophedon pattern across an area during mowing. FIGS. 25 and 26 illustrate the VMP robot customized for use in the sports industry. For example, FIG. 25 includes VMP robot 2500 customized to collect tennis balls including tubes 2501 and ball container 2502. Tubes 2501 include a means for generating suction such that tennis balls 2503 may be suctioned into tubes 2501 and into ball container 2502. Tubes 2501 extend outwards to direct tennis balls 2503. In some instances, customized VMP robot 2500 is used to facilitate ball collected during or at the end of a tennis session. In some instances, the tennis ball collecting robot may be used at the professional level as a replacement for human ball collectors. In some cases, tennis ball collecting robot may capture images of the environment, process the images and detect the location of tennis balls using computer vision technology. In some instances, the tennis ball collecting robot navigates around the tennis court, detecting balls and collecting them. In some instances, the tennis ball collecting robot positions itself at a side or back end of a tennis court after collecting all or a portion of all the free tennis balls or a predetermined number of tennis balls. In some cases, the tennis ball collecting robot may detect a ball approaching and may navigate in a direction away from the tennis ball to avoid any damage. In some instances, the processor learns over time which areas of the tennis court it is less likely to encounter an approaching tennis ball and hence optimal positioning. In some cases, the tennis ball collecting robot remains at a parked position until verbally instructed by a user to approach for balls. The processor may detect the user and approach to a nearby location. Other commands may also be possible, such as collect balls, back away, collect a predetermined number of balls (like 3, 5, or 15 for example), stop collecting balls, and the like. In some instances, the processor maps one or more adjacent tennis courts using mapping methods similar to those disclosed herein. In some instances, the processor or a user labels the one or more courts (e.g., court 1, court 2, court A, court B, etc.) In some cases, the user labels the one or more courts using an application of a communication device paired with the processor or a user interface on the VMP robot 2500 that may display the map. In some instances, the user may also choose one or more courts on which the tennis ball collecting robot is to remain or may create a virtual boundary within the map that the tennis ball collecting robot may not cross using the application. In some instances, multiple tennis ball collecting robots collaborate, each collecting balls in a particular area of the environment and positioning themselves optimally such that each player on the court may have access to the tennis balls within ball container 2502. In some instances, a similar type of robot is used for collection of golf balls, basketballs, etc. In another example, FIG. 26 illustrates the VMP robot 2600 customized to launch basketballs in the direction of basketball players during practice including tube 2601 within which basketballs are dropped and tube 2602 from which basketballs 2603 are launched. In some instances, the basketball launching robot allows basketballs to reach players at a faster rate as the processor of VMP robot 2600 may use sensor data to detect players without a basketball and immediately launch a basketball 2601 in their direction. In some cases, basketballs are autonomously fed into tube 2601 by another robot or by another mechanism. In such instances, the basketball launching robot also allows basketball players to maximize their playing time as no one player is required to collect their own rebound or rebounds of their teammates. Multiple basketball launching robots may be used simultaneously.

[0270] FIGS. 27A and 27B illustrate the VMP robot customized to function as robotic pressure cleaner including VMP robot 2700, water tank 2701, nozzle 2702, and cleaning agent tank 2703. In some instances, the robotic pressure cleaner may clean surfaces using a high-pressure liquid to remove unwanted matter from the surface. Examples of surfaces include cement road, hard wood floor, a side of a residential or commercial building, a vehicle body, and the like. In some cases, a hose connected to a water supply is connected to the robotic pressure cleaner and used to supply continuous water as opposed to a using water tank 2701. Using a hose connected to an external water source may be preferable as it may provide the robotic pressure cleaner with an unlimited water supply. In some instances, the robotic pressure cleaner further includes a motor or engine and a pump to generate the high-pressure liquid. In some instances, a motor or engine (e.g., electric or fuel powered) may be used to provide power to the water pump. In some cases, a fuel engine may be preferable as it may provide more freedom of maneuverability for the robotic pressure cleaner as it is not limited by connection to an electrical socket. In some cases, an electrically powered motor may be powered by one or more rechargeable batteries of the robotic pressure cleaner. An electrical motor powered by one or more rechargeable batteries of the robotic pressure cleaner may be preferable as it is a clean energy and provides the robotic pressure cleaner with freedom of maneuverability. In some instances, the robotic pressure cleaner is powered using electricity from an electrical socket. In other instances, the robotic pressure cleaner may be powered using various methods. In some cases, the water pump accelerate water to produce a release of high-pressured water. In some instances, the component used to release liquid, in this case nozzle 2702, is a high-pressure rated liquid release component. For example, a high-pressure rated hose may be used to release the high-pressure water onto the surface. In some cases, the water pressure may be adjustable for the task at hand. For example, different water pressures may be used for different types of surfaces, such as high water pressure for cleaning streets and lower water pressure for cleaning a vehicle. In some instances, the water pressure depends on the level of dirt build-up on the surface being cleaned. In some cases, the processor uses sensor data to predict the level of dirt build-up on a surface and autonomously adjusts the water pressure during cleaning. In other instance, a user chooses the water pressure using an application of a communication device paired with the processor or a user interface on the robotic pressure cleaner. In some cases, the user chooses a type of surface to be cleaned and the processor uses a default water pressure based on the type of surface chosen. In some instances, different cleaning detergents may be used in combination with the water, the cleaning agents being housed within cleaning agent tank 2703. For example, a cleaning detergent that assists with cleaning of grease or oil may be used to clean a surface such as the floor of an auto shop, a garage, or the like. In some cases, the robotic pressure cleaner may include more than one cleaning agent tanks and the processor may choose which cleaning agent to use based on the type of surface and type of dirt on the surface. In some instances, the user may choose which cleaning agent to used using the application or user interface of the robot. In some instances, the robotic pressure cleaner may use pellets, sand, or the like for assisting with removing dirt from a surface. For example, sand may be combined with the pressurized water to remove paint from a sidewalk. In some cases, the processor detects when the dirt has been removed from the surface to prevent damage to the surface from over cleaning. For example, using a high water pressure or pellets or sand on a surface for an extended period of time may damage the surface through erosion. In some instances, the liquid release component may be angled such that the high pressure water released is aimed at specific locations. For example, for cleaning a vehicle, side of a building or the like, the nozzle 2703 may be rotated 90 degrees to the right such that the direction of the pressurized liquid is aimed at the surfaces to be cleaned. In some cases, the processor may learn the optimal angle of the liquid release mechanism, optimal cleaning agent, optimal water pressure, optimal driving speed, and the like for loosening a particular type of dirt from a particular surface by observing certain factors over time, such as the length of time it took to loosen a particular type of debris from a particular surface, the amount of water pressure used, the angle of the liquid release mechanism, the amount of water consumed, the type of cleaning agent used, driving speed, and the like. In some instanced, the robotic pressure cleaner may reduce its speed to provide a more thorough cleaning of the surface. In some cases, one or more sensors scan the surface and detects areas that require further cleaning and the robot cleans those areas. In some instances, a user selects surfaces to be cleaned by choosing the surface in a map using the application. In some cases, a user controls the movement of the robotic pressure cleaner during cleaning using a communication device or provides a movement path by drawing it in a map using the application. In some cases, the processor maps and localizes using mapping and localization methods described herein. In some instances, multiple robotic pressure cleaners collaborate to pressure clean one or more surfaces using collaborative methods described herein. An example of a robotic pressure cleaner is further described in U.S. Patent Application No. 62/756,896, the entire contents of which is hereby incorporated by reference.

[0271] FIG. 28 illustrates the VMP robot customized to function as a robotic mobile sign including VMP robot 2800, user interface 2801, and virtual sign 2802. In some cases, the robotic mobile sign includes sensor windows behind which sensors for observing the environment are housed in an area below and/or above user interface 2801 such that the processor may observe the environment at am increased height. In some instances, the robotic mobile sign may be used in an airport. In some instances, the robotic mobile sign may be positioned at an arrivals gate and the virtual sign 2802 may display a name of an arriving airport guest. In some cases, the arriving airport guest may locate the robotic mobile sign and using the user interface 2801 confirm their presence. In some instances, the robotic mobile sign may proceed to direct the airport guest to a particular location, such as a location of a parked vehicle of their driver. In some instances, a user may provide text or an image to display on virtual sign 2802 to the processor using the user interface 2801 or an application of a communication device paired with the processor. The user may further provide a location to wait for a guest and a location to direct the guest to once they have confirmed their presence or once the processor autonomously detects the presence of the particular person. In some instances, the presence of a guest is detected by the entry of a unique code by the guest using the user interface or the robotic mobile sign may capture an image of the guest using a camera and transmit the image to the user on the application for confirmation. In some instances, the user may be able to track the robotic mobile sign using the application of the communication device. In some instances, the user may be able to direct the robotic mobile sign using the application. In some cases, the mobile robotic sign simply provides instructions to the guest whose name is displayed on virtual sign 2802. In some cases, the robotic mobile sign may be used for advertising purposes as well or other applications. In some instances, the robotic mobile sign is a service and users are required to provide payment for use. In some cases, multiple robotic mobile signs are parked in a parking area until requested for service by a user via an application of a communication device. In some instances, a control system manages operation of the multiple robotic mobile signs using control system management methods similar to those described herein. In some instances, processors of multiple robotic mobile signs autonomously collaborate to respond to requests from users using collaborative methods similar to those disclosed herein. FIG. 29A illustrates the VMP robot customized to function as robotic chair mover including VMP robot 2900 with moving component 2901. In some instances, the robotic chair mover moves chairs to a location by positioning itself in an optimal position relative to the chair 2902 to use the moving component 2901 to move chair 2902. FIG. 29B illustrates chair 2902 moved closer towards the chair 2903 by moving component 2901 of robotic chair mover. In some cases, the robotic chair mover moves chairs in a facility, such as a restaurant, to one area such that the floor may be clear of chairs for cleaning by, for example, a robotic surface cleaner. The robotic chair mover may move chairs back to their original location. In some cases, a robotic surface cleaner follows behind robotic chair mover as the robotic chair mover moves chairs for the robotic surface cleaner to access the floor beneath and around chairs. In some cases, the processor of the robotic chair mover initially maps the environment and marks the location of chairs within the map. In that way, the processor may know where to return chairs to after moving them. In some instances, the processor is provided with a floor map that includes the location of chairs for an event, for example. In some cases, the processor moves a collection of chairs all located in one area such that they are positioned as provided in the floor map. In some cases, the robotic chair mover may have the capability to stack or de-stack chairs. In some instances, the robotic chair mover localizes using similar localization methods as described herein. In some cases, processors of multiple robotic chair movers collaborate to position chairs in specific locations. In some instances, each robotic chair mover may be responsible for moving a particular number of chairs or may be responsible for placing all required chairs in a subarea of the environment.

[0272] FIG. 30 illustrates another configuration of a VMP robot 3000 that is customized to function as an item transportation robot. VMP robot 3000 is customized with platform 3001 on which items may be placed for transportation. Platform 3001 includes LIDAR 3002 and wheels 3003. Different types of sensors for mapping, localization, and navigation may be housed within compartment 3004 and behind sensor windows (not shown). In some cases, the item transportation robot may transport an item from a first location to a second location. For example, a consumer may order an item online and the item transportation robot may transport the item from a store or warehouse to a home of the consumer. The item may be a food item, a clothing item, a sports equipment item, an automotive item, a home and garden item, an office item, an electronics item, furniture, and the like. Different sized item transportation robots may be used to transport items of various sizes. In some instances, the consumer orders the item using an application of a communication device paired with a control system that manages one or more item transportation robots. In some cases, the control system receives the request for transportation of a particular item from a first location (e.g., warehouse) to a second location (e.g., consumer home). In some instances, the control system determines which item transportation robot shall execute the request based on the distance of the robot from the first location, the time to reach the first location, the battery or fuel level of the robot, the size capacity of the robot, and the like, and transmits the request to the processor of the item transportation robot chosen for execution. In some cases, item transportation robots autonomously park in a parking lot until departing to execute a request and return back to the parking lot after executing the request. In some instances, the consumer may view a status and/or the location of the item transportation robot using the application. In some cases, the item transportation robot is used within an establishment for transporting items. In some instances, a control system manages one or more item transportation robots operating within the establishment. For example, a consumer may order an item online from a particular storefront. Upon the consumer arriving at the storefront, an item transportation robot may be instructed to transport the ordered item from a storage location to the front of the store for the consumer to pick up. In some instances, the control system, being paired with the application from which the item was ordered, may detect when the consumer is within close proximity to the store front and may instruct the item transportation robot to transport the ordered item to the front of the store when the consumer is a predetermined distance away. In other instances, the consumer may use the application to alert the control system that they have arrived at the store front. In some cases, the control system may send an alert to the application when the item transportation robot has arrived at a delivery or item pick up location. In some instances, the application of the communication device from which an item is ordered may be used to specify an item, a particular time for delivery of the item, a store front pick up location, a delivery location, and the like. In some instances, the application may use GPS location technology for locating a consumer. In some cases, an item is delivered to a current location of the consumer. For example, a control system may locate a consumer that ordered a food item when the food item is ready for delivery and instruct the item transportation robot to deliver the food item to the current location of the consumer, which is some instances may change part way through delivery. In some cases, a consumer may select a previous order for repeat delivery. In some instances, the control system may detect the location of the consumer using the application of the communication device paired with the control system and may trigger particular instructions based on the location of the consumer. For example, delivery of an item to a current location of a consumer or transportation of an item from a storage location in the back of a store front when the consumer is close to reaching the store front. In some instances, the control system notifies the item transportation robot that a delivery is complete when the consumer reaches outside a predetermined range, at which point the robot may navigate back to a storage location or another location. In some cases, the item transportation robot retreats to a storage location, a parking lot, or another location after completing a delivery. For example, after the item transportation robot has delivered a food item to a consumer in a restaurant, the robot may navigate back to a kitchen area to receive another order. In some cases, a barcode or other type of identification tag located on the item transportation robot may be scanned by a scanner of the communication device after delivery of an item to alert the robot that it may navigate back to its storage location or another location. In other cases, other methods of alerting the item transportation robot that it may navigate back to its storage location or to another location may be used, such as, voice activation or activating a button positioned on the robot or weight sensor. In other cases, the item transportation robot may autonomously navigate back to a designated storage location, parking location, or charging location after delivery of an item. In some instances, the application or a user interface of the robot may provide information such as, when an item ordered is ready, a delay in order processing, a day and time an order will be ready, availability of an item, a status of the robot, etc. to the consumer. In other instances, information may be communicated using audio or visual methods. Examples of robot statuses may include, but are not limited to, in route to the item delivery location, parked at the item delivery location, item delivery complete, item delivery delayed, item delivery incomplete, stuck, collision with obstruction, damaged, container or platform cleaning required, and the like. In some instances, the item transportation robot may include sensors that may measure the amount of available space for items within a container or on a platform or the amount of available weight capacity. In some cases, the platform 3002 of the item transportation robot may accommodate multiple items for delivery to different locations. In some instances, the delivery locations of the multiple items are all within a predetermined radius. In some instances, the multiple items are all delivered to a central location in close proximity to all consumers that ordered the multiple items. In some instances, platform 3002 may be replaced with a container or may include a container within which items may be placed for transportation. In some instances, an operator or another robot places items on the platform. Further details of an item transportation robot are described in U.S. Patent Application No. 62/729,015, the entire contents of which are hereby incorporated by reference.

[0273] FIGS. 31A-31C illustrate yet another example of a VMP robot that may be customized for various functions. FIG. 31A illustrates a top perspective view of the VMP robot including casing 3100, securing racks 3101 with hole arrays for securing different structures to the VMP robot depending on the desired function of the robotic device, mecanum wheels 3102, windows 3103 for side, front, and back LIDAR sensors, and windows 3104 for cameras and other sensor arrays. FIG. 31B illustrates a top perspective view of the VMP robot without the casing. Camera 3105, sensor arrays 3106, LIDAR 3107, depth camera 3108, slots 3109 for additional sensors, slots 3110 for floor sensors, battery 3111 and wheel module 3112 including the wheel suspension and motor of wheel 3102. In other embodiments, other variations of VMP robot may be used. In some embodiments, a VMP robot or components thereof may be scaled in size in any direction to accommodate the intended function of the customized VMP robot. In some embodiments, the VMP robot may include multiple different components for performing a plurality of different tasks. An example of a multi-purpose robot is described in U.S. Patent Application No. 62/774,420, the entire contents of which is hereby incorporated by reference. For example, the VMP robot may include one or more of: a speaker module, a UV module, a compressor module, a dispensing module, an air pressure reduction and addition module, a brush module, a fluid module, a cloth module, a steam module, a dust collection module, a cleaning module, a mopping module, a supply carrying module, a material collection module, a service performing module, etc. In some embodiments, the supply carrying module includes one or more of: a module for carrying a battery, a module for delivery of electricity, a module for transmission of an electrical signal, and a module for delivery of food. In some embodiments, the supply carrying module performs at least some processing, wherein the processing comprises charging the battery, strengthening the electrical signal, or heating or cooking the food. In some embodiments, the supply carrying module is capable of dispensing with supply. In some embodiments, the supply includes a solid, a fluid, or a gas. In some embodiments, the gas is used for tire inflation. In some embodiments, the gas or fluid is used for power washing the floor of the environment. In some embodiments, the solid comprises a print receipt or cash from an ATM machine. In some embodiments, the fluid comprises paint, detergent, water, or hydrogen peroxide. In some embodiments, the supply carrying module generates a supply from a plurality of materials. In some embodiments, the supply carrying module carries supply comprising one or more of: a food tray, a medical patient, food, liquid, medication, gasoline, a power supply, and a passenger. In some embodiments, the supply carrying module comprises a module for delivery of pizza, wherein the module heats or cooks the pizza. In some embodiments, the service performing module repeats an electrical signal, transforms H₂O into H₂O₂, or trims grass. In some embodiments, the material collection module collects tennis balls or dust or debris.

[0274] Various different types of robotic devices with different configurations may employ the methods and techniques and include at least a portion of the components described herein. For example, FIG. 32 illustrates a robot for transporting luggage at the airport including luggage compartment 3200, sensor windows 3201 behind which sensors used for mapping and localization are housed, and user interface 3202. In some instances, a user may use user interface 3202 to choose a desired location for luggage drop-off or to enter an airline, flight number or reservation number which the processor may use to determine a drop-off location of the luggage. In some cases, a user may use an application of a communication device paired with a control system managing one or more robots to request luggage transportation from their current location or another location. The user may also use the application to choose a desired location for luggage drop-off or to enter an airline, flight number or reservation number which the processor may use to determine a drop-off location of the luggage. In some instances, robots for transporting luggage autonomously approach vehicles at the drop-off zone of an airport or arrivals area or another location. In some instances, a user requests a robot for luggage transport from a current location (e.g., determined by the processor using GPS of the communication device of the user) and flight number (or airline or reservation number), the control system managing the robots receives the request and transmits the request to a particular robot, the robot navigates to the current location of the user, the user enters an authorization code provided by the application using the user interface 3202 causing compartment 3200 to open, the user places their luggage in the compartment 3200 and presses a button on the robot to close compartment 3200, the robot autonomously transports the luggage to a luggage drop-off location based on the flight number provided by the user and the user proceeds to security. In other cases, the user may use the user interface 3202 to enter information. In some cases, other methods are used to open compartment 3200 or a user may open the compartment 3200 without any authorization or verification. In some instances, the control system determines which robot to transmit each request to based on various factors, such as a battery level of each robot, a current location of each robot, a pick up location of the luggage, a drop off location of the luggage, a size of the robot, and the like. In other cases, processors of robots collaborate to determine which robot responds to each request. In some instances, other implementation schemes fir the luggage transporting robots may be used. FIG. 33 illustrates another robot for transporting luggage at the airport including luggage platform 3300, luggage straps 3301, sensor window 3302 behind which sensors are positioned, and graphical user interface 3303 that a user may use to direct the robot to a particular location in an airport.

[0275] FIGS. 34A and 34B illustrate an example of security service robot including graphical user interface 3400 and sensor windows 3401 behind which sensors are housed. Sensors may include cameras, lasers, inertial measurement unit, and the like. The security service robot may use imaging devices to monitor an environment. In some instances, images captured by sensors of the robot may be viewed by a user using an application of a communication device paired with processor of the security service robot. In some instances, imaging devices record a live video which the user may access using the application. In some cases, the user may use the user interface 3400 or an application paired with the processor to choose an area of the environment for the robot to monitor by selecting the area in a map. In some cases, the user may choose a particular duration for the robot to spend monitoring each different area of the environment. In some instances, the security service robot includes a memory of verified people and may use image recognition technology to verify a detected person. In some cases, the processor notifies the user when an unverified person is detected by sending an alert to the application, by sounding an alarm, or by flashing lights or may alert the authorities. In some instances, processors of two or more security service robots collaborate to monitor areas of an environment, each robot being responsible for a particular area of the environment. Another example includes a robotic excavator illustrated in FIG. 35 with a compartment 3500 including a processor, memory, network card, and controller, one of two cameras 3501, sensor arrays 3502 (e.g., TOF sensors, sonar sensors, IR sensors, etc.), a LIDAR 3503, rear rangefinder 3504, and battery 3505. FIG. 36 illustrates an example of a robotic dump truck with a compartment 3606 including a processor, memory, and controller, one of two cameras 3607, sensor array 3608 (e.g., TOF sensors, sonar sensors, IR sensors, etc.), a LIDAR 3609, rear rangefinder 3610, battery 3611, and movement measurement device 3612. In some instances, robotic excavator may autonomously dig a hole in an area of an environment. In some cases, an application of a communication paired with the processor of the robotic excavator may be used to capture images of an environment. In some instances, the application generates a map of the environment by stitching images together at overlapping points. In some cases, the user may rotate the map, viewing the environment in three dimensions. In some cases, the user may choose an area in the map for the robotic excavator to dig using the application. In some cases, the user may draw the shape of the desired hole in two dimensions on the map displayed on the communication device via the application and may further choose the depth of the hole in different locations. In some instances, the application creates a rendering of the requested hole and the user may adjust specifications of the hole and re-render. For example, a user may use the application to capture images of their backyard. The application generates a three dimensional map of the backyard and the user may view the map in two dimensions or three dimensions using the application. The user may draw an oval for a swimming pool in a two dimensional top view of the back yard using drawing tools of the application. The user may specify a shallow depth in first area of the oval, a deep depth in a second area of the oval and in a third area a gradual change in depth between the shallow depth and deep depth. The user views a rendering of the hole created by the application and confirms. The application transmits the map and desired hole to the processor of the robotic excavator. Using SLAM techniques described herein the processor of the robotic excavator digs the oval hole for the swimming pool. In some instances, the processor of the robotic excavator collaborates with the processor of the robotic dump truck, such that the robotic dump truck strategically positions itself to receive the dug dirt from the robotic excavator. In some instances, the robotic dump truck follows the robotic excavator and positions itself such that the robotic excavator is not required to drive to dump the dug dirt. In some instances, a user may specify a location for the robotic dump truck to dump the dirt using the application. In some cases, two or more robotic excavators and/or robotic dump trucks may collaborate using collaboration methods such as those described herein. FIGS. 37A and 37B illustrate yet another variation of a commercial floor cleaner including LIDAR 3700, sensor windows 3701 behind which sensors for SLAM are located (e.g., camera, depth sensing device, laser, etc.), and cleaning tool 3702. The commercial floor cleaner may operate in a similar manner as described above for other surface cleaning robots.

[0276] In some embodiments, different coupling mechanisms may be used to couple additional structures to a VMP robot during customization. For example, FIGS. 38A and 38B illustrate an example of a coupling mechanism including connecting arm 3800 connected to VMP robot 3801, cap 3802 rotatably coupled to connecting arm 3800 and clamp 3803 coupled to connecting arm 3800 using a gear mechanism. Clamp 3803 may be used to clamp component 3804 that may be coupled to a larger structure such as a commercial floor scrubber, a wagon, a lawn mower, and the like. Component 3804 may rotate relative to clamp 3803. FIGS. 38C and 38D illustrate a cutaway view of the coupling mechanism including main gear 3805. As main gear 3805 rotates, the cap 3802 and clamp 3803 open and close depending on the direction of rotation. A portion of main gear 3805 is toothless (shown in FIG. 38D) such that rotation of main gear 3805 causes cap 3802 to open or clean before opening or closing clamp 3803. FIGS. 39A and 39B illustrate another example of a coupling mechanism including connecting arm 3900 connected to VMP robot 3901 and extendable arm 3902 that may be extended into an opening of similar shape and size within component 3903. Component 3903 may be coupled to a larger structure such as a seed planter, a shovel, a salt distributor, and the like. Extendable arm 3902 may be extended and retracted using, for example, a solenoid or hydraulics. FIGS. 40A and 40B illustrate yet another coupling mechanism including connecting arm 4000 connected to VMP robot 4001 with motor and gearbox 4002, first link 4003, middle link 4004, and end link 4005. Load receiver 4006 coupled to some payload (e.g., wheel lift, a rake, a disk for farming, etc.) approaches to connect with end link 4005 with pin 4007 fitting within groove 4008 of load receiver 4006. Note that load receiver 4006 is conical to help guide end link 4006 as they approach to connect. Once engaged, motor and gearbox 4002 rotate links 4003, 4004, and 4005, 90 degrees as illustrated in FIG. 40C. This causes pin 4007 to also rotate 90 degrees. As VMP robot 4001 drive forward, pin 4007 will move into the position shown in FIG. 40D thereby connecting the payload with the VMP robot 4001 as it navigates around an environment.

[0277] In some embodiments, robotic surface cleaners, such as those illustrated in FIGS. 4 and 5, may include helical brushes. FIGS. 41A-41C illustrate a brush 4100, according to some embodiments, in orthogonal view, front view, and end view, respectively. Brush 4100 may include a number of segmented blades 4102a, 4102b, 4102c, 4102d, and 4102e. In some embodiments, at least five segmented blades may be used. In some embodiments, at least four segmented blades or other number of blades may be used. In other embodiments, at most six blades may be used. The selection of number of segmented blades may be made based on the size of debris anticipated to be cleaned and the size of the robotic device. For example, fewer segmented blades may be selected to capture larger debris more effectively while more segmented blades may be selected to capture smaller debris more effectively. Although only five segmented blades are illustrated, one skilled in the art will readily recognize that other numbers of segmented blades may be enabled from this representative illustration. Each of segmented blades 4102a to 4102e may be positioned in a spiral path along hollow blade root 104 and mechanically coupled therewith. Segmented blades may be mechanically coupled with a hollow blade root in any manner known in the art without departing from embodiments provided herein. Furthermore, segmented blades 4102a to 4102e may be positioned equidistant from one another. This positioning allows for two counter-rotating brushes to be interleaved. FIG. 41B illustrates a number of cut-outs 4106 extending along each segmented blade 4102. Cut-outs may be sized and positioned to accommodate clearance of brush guard bars. This allows a portion of the segmented blade to extend beyond the brush guard. In addition, for FIG. 41B, blade ends 4112 may be rounded, wherein the contact edge of each segmented blade may be rounded or semi-rounded to provide for a gentler action on a cleaning surface and improve debris capture and pickup. In contrast, a flat blade end may tend to push debris resulting in an inefficient system. FIG. 41C illustrates hollow blade root 4104 defining a cylinder 4110 for receiving a drive axle (not illustrated). In order to mate hollow blade root embodiments with a drive axle, one or more keyways 4108a and 4108b may be formed along an interior surface of a hollow blade root. As may be appreciated, brushes disclosed herein may be manufactured from a variety of compounds without departing from embodiments disclosed herein. For example, brushes may be manufactured from a material such as, a natural rubber, a polymeric compound, a siliconized polymeric compound, a flexible material, a semi-flexible material, or any combination thereof. Furthermore, materials may be selected having a durometer shore A value in a range of approximately 50A to 70A or other range depending on the stiffness desired. In one embodiment, the material may have a durometer shore A value of approximately 60A, which represents a satisfactory and effective compromise between flexibility and strength. Centerline 120 is provided to illustrate an axis of rotation and centerline of brush embodiments illustrated herein.

[0278] FIGS. 42A-42C illustrate an example of a brush guard in orthogonal view, top view, and end view, respectively. Brush guard 4200 includes a number of brush guard bars 4202 that may be positioned substantially perpendicular with a pair of counter-rotating brushes. As noted above, cut-outs may be sized and positioned to accommodate clearance of brush guard bars. This allows a portion of the segmented blade to extend beyond the brush guard. In some embodiments, brush guard bars may be useful to prevent intake of cables and the like. In addition, in some embodiments, brush guards further include a pair of retainers 4204a and 4204b formed to capture a pair of counter-rotating brushes. Retainers may be positioned along an end of the brush guard.

[0279] FIGS. 43A-43C illustrate an example of a housing in orthogonal view, top view, and end view, respectively. Some housing embodiments are provided to contain pairs of interleaved counter-rotating brushes as disclosed herein. Housing 4300 includes at least cradles 4302a and 4302b for receiving a pair of interleaved counter-rotating brushes. Cradles 4302a and 4302b may be positioned on one end of housing 4300. End caps 4304a and 4304b may be positioned along an opposite end of housing 4300 from cradles 4302a and 4302b. Cradles and end caps may be provided to maintain interleaved counter-rotating brush pairs in a substantially parallel position allowing for interleaved brushes to operate properly.

[0280] FIGS. 44A-44C illustrate an example of a brush assembly 4400 in orthogonal view, side view, and end view. Housing 4402 retains interleaved counter-rotating brushes 4402a and 4402b in a substantially parallel position. Brush guard 4406 has a number of brush guard bars 4408 that may be positioned substantially perpendicular with interleaved counter-rotating brushes 4404a and 4404b. As noted above, cut-outs may be sized and positioned to accommodate clearance of brush guard bars. This allows a portion of the segmented blade to extend beyond the brush guard. The extension of segmented blades is illustrated at 4410 and 4412. As may be seen, a portion of each interleaved counter-rotating brush may extend from brush guard bars to contact a surface to be cleaned. In some embodiments, the extended portion of each interleaved counter-rotating brush may be different. For example, as illustrated, extension 4410 is greater than extension 4412. This difference may be useful to improve cleaning of debris from surfaces along a particular direction. In some embodiments, the extended portion of each interleaved counter-rotating brush may be substantially equal. In some embodiments, the extension may be from 2 to 12 mm or another range depending on the design. In some embodiments, the difference between extensions may be up to approximately 10 mm. Further illustrated is drive 4420 for providing mechanical rotation for interleaved counter-rotating brushes 4404a and 4404b. Any drive known in the art may be utilized without departing from embodiments provided herein.

[0281] As noted above for FIG. 41, the segmented blades are positioned in a spiral path which allows for interleaving of the counter-rotating blades. Without being bound by theory, it is proposed that the rotation of interleaved counter-rotating blades provides a measure of airflow induction that may improve the ability of the brush assembly to capture debris or liquids. As the two brushes rotate in opposite directions air may be trapped in a groove between the meshing helix blades of each brush, causing an increase in the density of air particles and pressure within the groove compared to outside the groove, thereby creating suction. An example of counter-rotating brushes is provided in U.S. patent application Ser. No. 15/462,839, the entire contents of which is hereby incorporated by reference. In other embodiments, various configurations are possible. For example, the two counter-rotating brushes may be of different length, diameter, shape (e.g., the path along which the blades follow, the number of blades, the shape of blades, size of blades, pattern of blades, etc.), and material while the two brushes are rotatably mounted parallel to the floor surface plane and are positioned a small distance from one another such that the blades at least partially overlap. In some embodiments, the two brushes are positioned different distances from the floor surface while remaining a small distance from one another such that the blades at least partially overlap. In some embodiments, more than two brushes are used (e.g., three, four, or six brushes). FIGS. 45A-45D illustrate four examples of different variations of brushes in terms of shape and size of blades that may be used. In some embodiments, a single brush may include a combination of different blades (e.g., shape, size, orientation, etc.). FIGS. 45E-45H illustrate four examples of different variations of brushes in terms of the number of blades.

[0282] FIG. 46A-46C illustrate an example of helical brushes of a robotic surface cleaner. FIG. 46A illustrates a bottom perspective view of a robotic surface cleaner with two interacting helical brushes 4600, wheels 4601, side brushes 4602 (bristles not shown), sensor window 4603 with openings 4604 behind which sensors, such as obstacle sensors, are housed, additional sensors 4605 (e.g., camera, laser, TOF sensor, obstacle sensor, etc.), and dustbin 4606. FIG. 46B illustrates a cutaway side view of the two helical brushes 4600 and dustbin 4606. A path of the dust and debris 4607 is illustrated, the dust and debris 4607 being suctioned from the floor in between two meshing flaps and into the dustbin 4606, the two meshing flaps creating an additional vacuum as described above. FIG. 46C illustrates a perspective view of the brush compartment, with helical brushes 4600 and brush guard 4608, the bars 4609 positioned such that they align with the spacing in between the flaps of the helical brushes 4600. In some embodiments, robotic surface cleaners may include one or more side brushes. Examples of side brushes are described in U.S. Patent Application Nos. 62/702,148, 62/699,101, 15/924,176, 16/024,263, and 16/203,385, the entire contents of which are hereby incorporated by reference. In some embodiments, the one or more side brushes may include a side brush cover that reduces the likelihood of entanglement of the side brush with an obstruction. An example of a side brush cover is disclosed in U.S. patent application Ser. No. 15/647,472, the entire contents of which is hereby incorporated by reference.

[0283] In some embodiments, brush assemblies may be coupled with a vacuum assembly. Vacuum assemblies are well-known in the art and, as such, any vacuum assembly in the art may be utilized without departing from embodiments provided herein. For example, a vacuum assembly may include a stationary or mobile configuration where brush assembly embodiments are in direct contact with a surface to be cleaned. In those examples, a vacuum assembly may follow the brush assembly to collect and store debris. One skilled in the art will readily recognize that brush assembly embodiments may be mechanically coupled in any number of manners to a vacuum assembly to provide a vacuum cleaner. In some embodiments, vacuum assemblies may be automatically or manually operated without limitation.

[0284] In some embodiments, robotic surface cleaners may include a spinning brush subsystem with a rotating assembly. In some embodiments, the rotating assembly comprises a plate with attached components such as, cleaning apparatuses, vacuum motor and debris container, and at least a portion of a mechanism for rotating the assembly. For example, the rotating assembly may include one of two components of a rotating mechanism, such as a gear, while the other portion of the rotating mechanism may be attached to the casing of the robotic device. In some embodiments, the plate of the rotating assembly may be positioned at the base of the casing of the robotic surface cleaner, such that the plate may be supported by the floor of the casing. In some embodiments, the rotating assembly may rotate in a plane parallel to the working surface at a speed with respect to the static casing of the robotic surface cleaner. In some embodiments, the casing of the robotic surface cleaner may include and/or house components of the robotic device such as, the wheels, wheel motor, control system and sensors. The casing may also include at least a portion of a mechanism for rotating the rotating assembly. For example, the casing may house a fixed motor with a rotating shaft, the rotating shaft fixed to the rotating assembly for rotation. As the rotating assembly rotates the cleaning apparatuses pass multiple times over the portion of the work surface covered by the robotic device. The number of times the cleaning apparatuses pass over the area covered is dependent on the rotational speed of the assembly and the speed of the robotic device. In some embodiments, the rate of rotation of the rotating assembly should allow the rotating assembly, and hence cleaning apparatuses, to rotate 360 degrees at least twice while covering the same area. In some embodiments, the rotational speed of the rotating apparatus adjusts with the speed of the robotic surface cleaner. This increase in coverage in addition to the added friction between cleaning apparatuses and the working surface from rotation of the rotating assembly results in a more thoroughly cleaned area. Cleaning apparatuses may include, but are not limited to, brushes such as roller or flat brushes, mop, cleaning cloth, scrubber, UV sterilization, steam mop, and dusting cloth. In some cases, there is no cleaning apparatus and suction from the motor is purely used in cleaning the area. In some embodiments, the rotating assembly may include two or more cleaning apparatuses. In some embodiments, only a portion of or all of the total number of cleaning apparatuses are operational during cleaning. In some embodiments, different types of cleaning apparatuses may be easily exchanged from the rotating assembly. In some embodiments, the processor of the robotic surface cleaner may operate different cleaning apparatuses during different portions of a cleaning session. In some embodiments, a user or the processor may choose which cleaning apparatuses to use in different areas of the environment (e.g., based on sensor data for the processor).

[0285] Several different mechanisms for rotating the rotating assembly may be used. In one embodiment, an electrically driven mechanism is used to rotate the rotating assembly. For example, the plate of the rotating assembly may be used as a gear, having gear teeth around the edges of the plate. The gear plate may then interact with a second gear attached to the casing of the robotic device and rotationally driven by an electric motor. Rotation of the gear driven by the motor causes rotation of the gear plate of the assembly. In a further example, a fixed electric motor with rotating shaft housed within the casing of the robotic device is used to rotate the rotating assembly. The rotating shaft is centrally fixed to the plate of the rotating assembly such that rotation of the shaft driven by the electric motor causes rotation of the rotating assembly. In other embodiments, a mechanically driven mechanism is used to rotate the rotating assembly. For example, rotation of the wheels may be coupled to a set of gears attached to the casing of the robotic device, such that rotation of the wheels causes rotation of the gears. The wheel driven gears may then interact with the plate of the rotating assembly, the plate being a gear with gear teeth around its edges, such that rotation of the wheel driven gears causes rotation of the rotating assembly.

[0286] In one embodiment, the rotating assembly rotates in a clockwise direction while in other embodiments the rotating assembly rotates in a counterclockwise direction. In some embodiments, the assembly may rotate in either direction, depending on, for example, user input or the programmed cleaning algorithm. For example, the cleaning algorithm may specify that after every 50 rotations the direction of rotation be switched from counterclockwise to clockwise and vice versa. As a further example, the user may choose the direction of rotation and/or the frequency of alternating direction of rotation. In some instances, the direction of rotation changes back and forth each time the same area is covered by the robot. In yet another embodiment, rotation of the rotating assembly may be set for a predetermined amount of time. This may be set by, for example, the user or the programmed cleaning algorithm. In some embodiments, rotation of the assembly may be activated and deactivated by the user. In yet another embodiment, the speed of rotation of the assembly may be adjusted by the user. In some embodiments, the robotic device operates without rotation of the rotating assembly. In some embodiments, the rotating assembly may be set to oscillate wherein the assembly rotates a predetermined number of degrees in one direction before rotating a predetermined number of degrees in the opposite direction, resulting in an oscillating motion. In some embodiments, the degree of rotation may be adjusted. For example, the assembly may be set to rotate 270 or 180 degrees before rotating the same amount in the opposite direction.

[0287] In some embodiments, electrical contacts are placed on the casing of the robotic device and on the plate of the assembly such that electrical contacts on the casing are in constant contact with electrical contacts on the plate during rotation of the assembly. This ensures power may continuously flow to electrical components mounted to the rotating plate of the assembly.

[0288] FIG. 47 illustrates a bottom view of robotic vacuum 4700 with rotatable assembly 4706. Casing 4701 of robotic vacuum 4700 houses stationary components, including but not limited to, driving wheels 4702, steering wheel 4703, a control system (not shown), batteries (not shown), a processor (not shown) and a means to rotate the assembly 4706 (not shown). Casing 4701 may further house other components without limitation. Components shown are included for illustrative purposes and are not intended to limit the invention to the particular design shown. In the example shown, casing 4701 further houses sensors 4704 and side brushes 4705. Rotating assembly 4706 of robotic vacuum 4700 is supported by and rotates at a predetermined speed with respect to static casing 4701. Assembly 4706 includes main cleaning apparatuses 4707, vacuum motor (not shown), and debris container (not shown). In other embodiments, assembly 4706 may include additional components or any other combination of components than what is shown.

[0289] FIG. 48A illustrates a perspective view of casing 4701 of robotic vacuum 4700. Rotating assembly 4706 fits within opening 4808 in casing 4701. The diameter of opening 4808 is smaller than the diameter of rotating assembly 4706 such that rotating assembly 4706 may be supported by casing 4701. Electric motor driven gear 4809 rotate assembly 4706. FIG. 48B illustrates a perspective view of rotating assembly 4706 of robotic vacuum 4700. Rotating assembly 4706 comprises plate 4810 with attached debris container 4812, vacuum motor 4813, and cleaning apparatus 4814. In this example, plate 4810 is a gear plate with gear teeth used in rotating assembly 4706. As electrically driven gear 4809 rotates, it interacts with gear teeth of gear plate 4809 causing assembly 4706 to rotate.

[0290] In some embodiments, as robotic vacuum 4700 drives through an area, motor and gear set 4809 rotate causing plate 4810 of rotating assembly 4706 to rotate in a plane parallel to the working surface. In some embodiments, the rate of rotation of rotating assembly 4706 should allow rotating assembly 4706, and hence cleaning apparatuses, to rotate 360 degrees at least twice while covering the same area. The rotational speed of the rotating assembly used to achieve at least two full rotations while covering the same area is dependent on the speed of the robotic device, where a high rotational speed is required for a robotic device with increased movement speed.

[0291] FIG. 49 illustrates casing 4900 of a robotic vacuum with rotating assembly 4901. In this illustration, there are no components housed within casing 4900 or attached to rotating assembly 4901 for simplicity. The purpose of FIG. 49 is to demonstrate an embodiment, wherein rotating assembly 4901, supported by the floor of robotic vacuum casing 4900, is electrically connected to casing 4900 by electrical contacts. Robotic vacuum casing 4900 contains electrical contacts 4902 and the plate of rotating assembly 4901 contains electrical contacts 4903. In this configuration, electrical contacts 4902 of casing 4900 and electrical contacts 4903 of rotating assembly 4901 are in constant connection with one another as rotating assembly 4901 spins. This ensures any electrical components mounted to rotating assembly 4901 receive electrical power as required during rotation of assembly 4901.

[0292] Various cleaning apparatuses may be coupled to the rotating assembly. Various configurations may be used for rotating the one or more cleaning apparatuses. For example, FIG. 50A illustrates a bottom perspective view of a rotating plate 5000 of a surface cleaning robot 5001, to which a cleaning apparatus may be attached, such as a dust pad or scrubbing pad. For instance, FIG. 50B illustrates a mop 5002 attached to rotating assembly 5000.

[0293] Methods described herein for improving the cleaning efficiency of a robotic surface cleaner may be implemented independently or may be combined with other methods for improving cleaning efficiency. For example, both a rotating cleaning assembly and a vacuum motor with increased power may be implemented in combination with one another to improve cleaning efficiency. As a further example, counter-rotating brushes may also be implemented into the combination to further improve cleaning efficiency. Further details on a spinning cleaning tool subsystem are provided in U.S. patent application Ser. Nos. 14/922,143 and 15/878,228, the entire contents of which are hereby incorporated by reference.

[0294] In some embodiments, robotic surface cleaners may include a mop attachment having a passive liquid (or fluid) flow pace control using a pressure actuated valve to provide mopping functionality to a robotic surface cleaning device. In some embodiments, the removable mop attachment module includes a frame; a reservoir positioned within the frame, one or more drainage apertures positioned on the bottom of the removable mop attachment module that allow liquid to flow out of the reservoir; a breathing aperture, which may allow air into the reservoir, positioned on an upper portion (or on another location in some cases) of the reservoir, and a pressure actuated valve positioned on an inner surface of the reservoir and under the breathing aperture(s), sealing the reservoir while in a closed position and opening when a certain amount of negative air pressure has built up inside the reservoir due to the draining of liquid, letting some air inside the reservoir through the breathing aperture(s). In some embodiments, the pressure actuated valve includes a valve body, adapted for mounting on at least an air passage; a valve member connected to the valve body having at least a flexible element moveable relative to the valve body that forms a seal on the air passage when in a closed position, wherein a certain pressure difference between the two sides of the valve member moves the flexible element from the closed position to an open position letting air enter the air passage. It will be obvious to one skilled in the art that the pressure actuated valve may function with various fluids capable of creating a negative pressure behind the valve and opening the valve.

[0295] FIG. 51 illustrates an overhead view of a removable mopping attachment 5100 used in some embodiments. A frame 5102 houses a reservoir 5104 in which cleaning liquid may be stored. The reservoir 5104 has an opening 5106 for refilling cleaning liquid, which will be sealed by a lid (not shown). A series of apertures 5108 as air breathing inlets are positioned on an upper portion of the reservoir. A pressure actuated valve 5110 is mounted under the air breathing inlets and seals the reservoir 5104 from inside when it is in a closed position. Member 5402 is a part of the valve 5110, discussed below.

[0296] FIG. 52 illustrates a bottom view of the mopping attachment 5100. On the bottom of the frame 5102, liquid drainage apertures 5202 let the cleaning liquid out of the reservoir 5104 and dampen a mopping cloth (not shown) that may be attached to the underside of the mopping extension 5100 via attaching devices 5200. It will be obvious to one skilled in the art that the attaching devices 5200 for attaching the mop cloth could be one of many of the known attachment mechanisms in the art such as Velcro, magnets, snap fasteners, a zipper, a railing system, or a simple cloth grabbing mechanism.

[0297] FIG. 53 illustrates an overhead view of the pressure actuated valve 5110, according to some embodiments. The pressure actuated valve 5110 has a flexible member 5300, which seals the reservoir and stops air from entering the reservoir through the breathing inlets illustrated in FIG. 51. It will be obvious to one skilled in the art that the flexible member 5300 could be made of various flexible materials, such as, but not limited to, silicon, rubber, or plastic.

[0298] FIG. 54 illustrates a cross sectional view of the pressure actuated valve 5110 installed on an inner surface of a side 5400 of the reservoir 5104. In the example illustrated, the pressure actuated valve is in a closed position. The pressure actuated valve 5110 is mounted inside the reservoir 5104 using a member 5402 in a way that it seals the reservoir 5104. When the reservoir 5104 is sealed and the liquid inside the reservoir 5104 drains through the drainage apertures 5202 (shown in FIG. 52), a negative pressure builds up inside the reservoir 5104. When the negative pressure gets high enough, the pressure difference between a first and a second side of the valve 5110 moves flexible member 5300 from a closed position to an open position, wherein flexible member 5300 is drawn away from the side 5400 of the reservoir. This allows some air into the reservoir through the intake apertures 5108, which increases the air pressure inside the reservoir 5104, allowing liquid to drain from the drainage apertures once again.

[0299] FIG. 55 shows a cross sectional view of the pressure actuated valve 5108 in an open position. Upon reaching a certain amount of negative pressure within the reservoir 5104, the flexible member 5300 is drawn away from the side 5400 of the reservoir 5104 by the built up negative pressure, unblocking the intake apertures 5108, which lets air momentarily inside the reservoir 5104 until the negative pressure has equalized enough to cause the flexible member 5300 to return to the closed position. It will be obvious to one skilled in the art that the pressure actuated valve 5110 could be installed on the top or side or another location on the reservoir. In embodiments, the pressure actuated valve is installed higher than the reservoir's maximum allowable liquid level. It will be obvious to one skilled in the art that the member 5402 may be mounted on the reservoir 104 using various known mechanism in the art.

[0300] FIG. 56 illustrates a perspective view of an example of a removable mopping attachment 5100 and how it may be attached to or removed from a robotic surface cleaning device 5600. The robotic surface cleaning device 5600 has a slot 5602 on the underside thereof for receiving the mopping attachment. The mopping attachment 5100 may be installed within the slot 5602 such that the mopping cloth (not shown) on the bottom of the mopping attachment 5100 is in contact with the work surface.

[0301] In some embodiments, robotic surface cleaners include a single module for mopping and vacuuming. For example, FIG. 57 illustrates a robotic surface cleaner 5700 with a single mopping and vacuuming module 5701 that may be slidingly coupled to robotic surface cleaner 5700 during cleaning and detached to access the dustbin or fluid reservoir, for example. Module 5701 includes vacuum compartment 5702 (e.g., dustbin, impeller, etc.) and mopping compartment 5703 (e.g., fluid reservoir, air pressure valve, mopping cloth, etc.). The single mopping and vacuuming module may be used for dispensing water using a motorized method during mopping and collecting dust during vacuuming. The single mopping and vacuuming module may be detachable as a single unit from the robotic surface cleaning device.

[0302] In some embodiments, the drainage apertures may further include a flow reduction valve positioned on the drainage apertures to reduce the flow of liquid from the reservoir. FIG. 58 illustrates an example of flow reduction valves 5800 positioned on drainage apertures 5202 to reduce the flow of liquid from reservoir 5104, according to some embodiments. Further details of a pressure actuated valve for controlling the release of liquid for mopping are described in U.S. patent application Ser. No. 16/440,904, the entire contents of which is hereby incorporated by reference.

[0303] In some embodiments, robotic surface cleaners include a control mechanism for mopping that controls the release of liquid. In some embodiments, the release of liquid by the control mechanism may be determined by the motion of the robotic surface cleaning device. In some embodiments, the release of liquid by the control mechanism may be determined by the rotary motion of one or more non-propelling wheels of the robotic surface cleaning device. For example, a rotatable cylinder with at least one aperture for storing a limited quantity of liquid is connected to an outside member such as a non-propelling (non-driving) wheel of the robotic surface cleaning device. The cylinder is connected to the non-propelling wheel directly or via an axle or a gear mechanism such that cylinder rotation is controlled by the rotation of the wheel. More particularly, the axle turns the rotatable cylinder when the motion of the robotic surface cleaning device occurs. In some embodiments, the axle turns the rotatable cylinder when the rotary motion of one or more non-propelling wheels of the robotic surface cleaning device occurs. The cylinder is within or adjacent to a liquid reservoir tank. There is a passage below the cylinder and between the cylinder and a drainage mechanism. Each time at least one aperture is exposed to the liquid within the reservoir tank, it fills with liquid. As the wheel turns, the connected cylinder is rotated until the aperture is adjacent to the passage. Upon exposure to the passage, the liquid will flow out of the aperture by means of gravity, pass through the passage, and enter the drainage mechanism, whereby the liquid is delivered onto the working surface. In some embodiments, the drainage mechanism disperses liquid throughout a plane. For example, a drainage mechanism may include a hollow body with a perforated underside through which liquid may pass to surfaces below. In some embodiments, the faster the non-propelling wheels rotates, the faster the cylinder turns, the faster the aperture releases liquid into the passage. Moreover, if the non-propelling wheels rotates, say, twice faster, the cylinder turns twice faster, and the aperture releases liquid into the passage twice faster. Furthermore, when the rotary motion of the non-propelling wheel halts, the cylinder stops turning, and the further release of liquid into the passage is stopped as well. It is worth meanwhile to note that speed of the robotic surface cleaning device may be proportional to the rate of the rotary motion of the non-propelling wheels. The above reasoning explains that rapidity of the release of liquid into the passage and the drainage mechanism may be proportional to the speed of the robotic surface cleaning device and/or the rate of the rotary motion of one or more non-propelling wheels.

[0304] FIG. 59 illustrates a bottom view of a robotic floor cleaning device 5900. Robotic floor cleaning device 5900 is comprised of chassis 5901, non-propelling wheel 5902, motor 5903, mop module 5904, and propelling wheels 5906. Rotatable cylinder 5907 is positioned inside mop module 5904 and is connected to non-propelling wheel 5902 by connecting outside member 5908 that transfers rotational movement to the cylinder 5907. This connecting outside member may be comprised of an axle and/or gear mechanism.

[0305] FIG. 60A illustrates a cross-sectional view of the mop module 5904. In this embodiment, the rotatable cylinder 5907 is positioned adjacent to the liquid reservoir 6001, however, other arrangements are possible. Mop module 5904 is comprised of frame 6002, liquid reservoir 6001 containing liquid 6003, rotatable cylinder 5907 (which includes aperture 6004 and axle 6005), passage 6006, and drainage mechanism 6007. In this position, liquid 6003 fills aperture 6004 and rotatable cylinder 5907 is blocking liquid from escaping reservoir 6001. As axle 6005 turns, cylinder 5907 will be rotated in direction 6008 and aperture 6004 will be rotated toward passage 6006. FIG. 60B illustrates a cross-sectional view of mop module 5904 after cylinder 5907 has been rotated in direction 6008. In this position, cylinder 5907 is rotated so that aperture 6004 is adjacent to passage 6006. In this position, liquid that had entered aperture 6004 while it was previously adjacent to liquid 6003 will flow downwards through passage 6006 by means of gravity into drainage mechanism 6007, to be dispersed onto the working surface. Liquid 6003 is only delivered to drainage mechanism 6007 when cylinder 5907 is rotating. Since rotation of cylinder 5907 is controlled by rotation of axle 6005, liquid is no longer delivered to drainage mechanism 6007 when axle 6005 stops rotating. The arrangement of components may vary from the example illustrated without departing from the scope of the invention.

[0306] FIGS. 61A and 61B illustrate a cross-sectional view of an embodiment wherein the rotatable cylinder is provided within the reservoir (rather than adjacent to it). FIG. 61A illustrates mop module 6104 is comprised of frame 6102, liquid reservoir 6101 containing liquid 6103, rotatable cylinder 6100 (which includes aperture 6104 and axle 6105), passage 6106, and drainage mechanism 6107. In this position, liquid 6103 fills aperture 6104 and rotatable cylinder 6100 is blocking liquid from escaping reservoir 6101. As axle 6105 turns, cylinder 6100 will be rotated in direction 6108 and aperture 6104 will be rotated toward passage 6106. FIG. 61B illustrates a cross-sectional view of mop module 6104 after cylinder 6100 has been rotated in direction 6108. In this position, cylinder 6107 is rotated so that aperture 6104 is adjacent to passage 6106. In this position, liquid that had entered aperture 6104 while it was previously adjacent to liquid 6103 will flow downwards through passage 6106 by means of gravity into drainage mechanism 6107, to be dispersed onto the working surface. Liquid 6103 is only delivered to drainage mechanism 6107 when cylinder 6100 is rotating. Since rotation of cylinder 6100 is controlled by rotation of axle 6105, liquid is no longer delivered to drainage mechanism 6107 when axle 6105 stops rotating.

[0307] FIG. 62 illustrates a top view of mop module 6204 with non-propelling wheel 6200 connected to rotatable cylinder 6203 with aperture 6202 by member 6201. When the robotic floor cleaning device is operational, non-propelling wheel 6200 rotates thereby transferring rotational motion to rotatable cylinder 6203 by connecting member 6201.

[0308] It should be understood that in some embodiments, a frame to hold the mop module components may be omitted, and the components thereof may be built directly into the robotic surface cleaning device. The size, number, and depth of apertures on the rotatable cylinder as well as the rotation speed of the rotatable cylinder may be modified to adjust the liquid flow rate from the reservoir. In some embodiments, a removable mop module comprising the elements described above may be provided as an attachment to a robotic surface cleaning device. That is, the frame and all components may be removed and replaced as desired by an operator. In some embodiments, the liquid flow rate from said reservoir may be adjusted by adding additional cylinders having at least one aperture and corresponding passages.

[0309] In some embodiments, the rotatable cylinder with at least one aperture is connected to a motor and the motor rotates the rotatable cylinder. In some embodiments, a processor of the robotic surface cleaning device may control operation of the motor based on information received from, for example, an odometer or gyroscope providing information on movement of the robotic surface cleaning device, optical encoder providing information on rotation of the wheels of the robotic surface cleaning device or its distance travelled, user interface, floor sensors, timer, sensors for detecting fluid levels or other types of device that may provide information that may be useful in controlling the operation of the motor and hence the release of cleaning fluid. For example, in some embodiments, the motor may operate based on movement of the robotic surface cleaning device. For instance, if the mobile robotic device is static the motor will not operate, in which case liquid will not vacate the liquid reservoir. In other embodiments, the motor may become operational at predetermined intervals wherein intervals may be time based or based on the distance travelled by the robotic surface cleaning device or based on any other metric. In some embodiments, the motor may become operational upon the detection of a particular floor type, such as hardwood or tiled flooring. In some embodiments, the motor may become operational upon the detection of a mess on the floor. In some embodiments, the motor may operate based on whether or not the wheels of the robotic surface cleaning device are spinning. In some embodiments, a user of the robotic surface cleaning device may control the operation of the motor and hence the release of cleaning fluid by, for example, pushing a button on the robotic surface cleaning device or remote control. In some embodiments, the motor controlling the cylinder and hence the release of cleaning fluid may automatically cease operation upon detecting the depletion of the cleaning fluid.

[0310] In some embodiments, the motor may operate at varying speeds thereby controlling the speed of the cylinder and release of fluid. For example, if the motor is operating at a high speed, liquid is released more frequently. Therefore, if the speed of the robotic surface cleaning device is maintained yet the speed of the motor is increased, more liquid will be dispersed onto the work area. If the motor is operating at a lower speed, liquid is released less frequently. Therefore, if the speed of the robotic surface cleaning device is maintained yet the power of the motor is decreased, less liquid will be dispersed onto the work area. In some embodiments, the processor of the robotic surface cleaning device may control the speed of the motor. In some embodiments, the speed of the motor may be automatically adjusted by the processor based on the speed of the robotic surface cleaning device, the type of floor, the level of cleanliness of the work area, and the like. For example, floor sensors of the robotic surface cleaning device may continually send signals to the processor indicating the floor type of the work surface. If, for instance, the processor detects a carpeted work surface based on the sensor data, then the processor may cease operation of the motor, in which case liquid will not be released onto the carpeted surface. However, if the processor detects a hard floor surface, such as a tiled surface, the processor may actuate the motor thereby rotating the cylinder and releasing cleaning liquid onto the floor. In some embodiments, the processor may be able to differentiate between different hard floor surface types and direct actions accordingly. For example, mopping on a hardwood floor surface may damage the hardwood floor. If during a mopping sequence the processor detects that the floor has transitioned from a tiled surface to a hardwood surface based on sensor data, the processor may cease operation of the mopping mechanism. In some embodiments, the speed of the motor may be increased and decreased during operation by the processor. In some embodiments, the user of the robotic surface cleaning device may increase or decrease the speed of the motor and hence the amount of cleaning fluid released by, for example, a button on the robotic surface cleaning device or a remote control or other communication device.

[0311] FIG. 63 illustrates a top view of motor 6300 connected to rotatable cylinder 6303 with aperture 6302 by member 6301. When the robotic surface cleaning device is operational, motor 6300 operates thereby transferring rotational motion to rotatable cylinder 6303 by connecting member 6301. Further details of a mopping module with controlled liquid release are provided in U.S. patent application Ser. Nos. 15/673,176 and 16/058,026, the entire contents of which are hereby incorporated by reference.

[0312] In some instances, the mopping module includes a reservoir and a water pump driven by a motor that delivers water from the reservoir indirectly or directly to the driving surface. In some embodiments, the water pump autonomously activates when the robotic surface cleaner is moving and deactivates when the robotic surface cleaner is stationary. In some embodiments, the water pump includes a tube through which fluid flows from the reservoir. In some embodiments, the tube may be connected to a drainage mechanism into which the pumped fluid from the reservoir flows. In some embodiments, the bottom of the drainage mechanism includes drainage apertures. In some embodiments, a mopping pad may be attached to a bottom surface of the drainage mechanism. In some embodiments, fluid is pumped from the reservoir, into the drainage mechanism and fluid flows through one or more drainage apertures of the drainage mechanism onto the mopping pad. In some embodiments, flow reduction valves are positioned on the drainage apertures. In some embodiments, the tube may be connected to a branched component that delivers the fluid from the tube in various directions such that the fluid may be distributed in various areas of a mopping pad. In some embodiments, the release of fluid may be controlled by flow reduction valves positioned along one or more paths of the fluid prior to reaching the mopping pad.

[0313] Some embodiments provide a mopping extension unit for robotic surface cleaners to enable simultaneous vacuuming and mopping of work surface and reduce (or eliminate) the need for a dedicated mopping robot to run after a dedicated vacuuming robot. In some embodiments, a mopping extension may be installed in a dedicated compartment in the chassis of a robotic surface cleaning device. In some embodiments, a cloth positioned on the mopping extension is dragged along the work surface as the robotic surface cleaning device drives through the area. In some embodiments, nozzles direct fluid from a cleaning fluid reservoir to the mopping cloth. The dampened mopping cloth may further improve cleaning efficiency. In some embodiments, the mopping extension further comprises a means for moving back and forth in a horizontal plane parallel to the work surface during operation. In some embodiments, the mopping extension further comprises a means for moving up and down in a vertical plane perpendicular to the work surface to engage or disengage the mopping extension. In some embodiments, a detachable mopping extension may be installed inside a dedicated compartment within the chassis of a robotic surface cleaning device. FIG. 64 illustrates a bottom view of an example of a detachable mopping extension 6400. In some embodiments, the mopping extension may be attached to the chassis of a robotic surface cleaning device (not shown). The mopping extension includes a frame 6401 that supports a removable mopping cloth 6402 and a latch 6403 to secure and release the mopping extension to and from the robotic surface cleaning device.

[0314] FIG. 65 illustrates an example of internal components of a mopping extension 6500. The frame 6501 supports the mop components. A latch 6503 secures the mopping extension to the chassis of the robotic device and may be released to detach the mopping extension. In some embodiments, the mopping extension further includes a refillable fluid reservoir 6504 that stores cleaning fluid to be dispersed by nozzles 6505 onto the mopping cloth 6502. In some embodiments, the nozzles continuously deliver a constant amount of cleaning fluid to the mopping cloth. In some embodiments, the nozzles periodically deliver predetermined quantities of cleaning fluid to the cloth.

[0315] FIG. 66 illustrates an example of a mopping extension 6600 with a set of ultrasonic oscillators 6606 that vaporize fluid from the reservoir 6604 before it is delivered through the nozzles 6605 to the mopping cloth 6602. Metal electrodes 6607 provide power from a main battery (not shown) of the robotic surface cleaning device to the ultrasonic oscillators. In some embodiments, the ultrasonic oscillators vaporize fluid continuously at a low rate to continuously deliver vapor to the mopping cloth. In some embodiments, the ultrasonic oscillators turn on at predetermined intervals to deliver vapor periodically to the mopping cloth. In some embodiments, a heating system may alternatively be used to vaporize fluid. For example, an electric heating coil in direct contact with the fluid may be used to vaporize the fluid. The electric heating coil may indirectly heat the fluid through another medium. In other examples, radiant heat may be used to vaporize the fluid. In some embodiments, water may be heated to a predetermined temperature then mixed with a cleaning agent, wherein the heated water is used as the heating source for vaporization of the mixture.

[0316] In some embodiments, the mopping extension includes a means to vibrate the mopping extension during operation. FIG. 67A illustrates an example of a mopping extension 6700 with eccentric rotating mass vibration motors. FIG. 67B illustrates a close up perspective view of an eccentric rotating mass vibration motor 6708. Eccentric rotating mass vibration motors rely on the rotation of an unbalanced counterweight 6709 to provide vibrations to the mopping extension.

[0317] FIG. 68 illustrates an example of a corresponding robotic vacuum to which a mopping extension 6800 may be attached. The mopping extension 6800 fits into a compartment 6810 on the underside of the robotic vacuum 6811 such that a cloth of the mopping extension may be caused to make contact with the work surface as the robotic vacuum 6811 drives. In some embodiments, the mopping extension includes a means to move the mopping extension back and forth in a horizontal plane parallel to the work surface during operation. FIG. 69 illustrates a side elevation view of an example of a robotic vacuum with a mechanism for moving the mopping extension back and forth. An electric motor 6912 positioned inside the chassis of the robotic vacuum 6911 transfers movements to the mopping extension 6900 through a rod 6913 to tabs 6914 on the mopping extension.

[0318] In some embodiments, the mopping extension includes a means to engage and disengage the mopping extension during operation by moving the mopping extension up and down in a vertical plane perpendicular to the work surface. In some embodiments, engagement and disengagement may be manually controlled by a user. In some embodiments, engagement and disengagement may be controlled automatically based on sensory input. FIG. 70A illustrates a side view of an examples of a robotic vacuum 7011 with a means for engaging and disengaging a mopping extension 7000. (The mopping extension is shown not attached to the robotic vacuum in this example to more clearly show details; another example in which the mopping extension is attached will be provided later.) An electric servomotor 7015 positioned within the chassis of the robotic vacuum pushes forward and pulls back wedges 7016 that raise and lower springs 7017 to which the mopping extension 7000 may be attached. When the wedges are pulled back, as shown in FIG. 70A, the mopping extension, when attached, will be engaged. Referring to FIG. 70B, when the wedges 7016 are pushed forward in a direction 7018 by the electric servomotor 7015, the springs 7017 are raised and the mopping extension 7000 is disengaged. FIG. 70C and FIG. 70D illustrate an example of an alternate method for engaging and disengaging a mopping extension. An oval wheel 7019 positioned in the chassis of a robotic vacuum 7011 is turned by an electric motor 7020, which causes the wheel to push down a plate 7021. When the wheel is not pushing the plate down, springs 7017 are not pushed down and the mopping extension 7000 is not engaged. In FIG. 70D the wheel 7019 is pushing down the plate 7021 causing the springs 7017 to be pushed down which lowers the mopping extension 7000, engaging it.

[0319] FIGS. 71A and 71B illustrate and example of a robotic vacuum 7011 with a mopping extension 7000 attached. In FIG. 71A, the springs 7017 are not lowered and the mopping extension 7000 is in a disengaged position, where the mopping extension cannot make contact with the work surface 7022. In FIG. 71B the springs 7017 are lowered and the mopping extension 7000 is in an engaged position, such that the mopping extension makes contact with the work surface 7022. Further details of a mopping extension for robotic surface cleaners are provided in U.S. patent application Ser. Nos. 14/970,791 and 16/375,968, the entire contents of which are hereby incorporated by reference.

[0320] In some embodiments, robotic surface cleaners include steam cleaning apparatus. FIG. 72 illustrates an overhead view of the underside of a robotic surface cleaning device 7200. A reservoir 7201 is positioned within the robotic surface cleaning device. Ultrasonic oscillators 7202 are connected to the reservoir and vaporize the water to produce steam. (Other means for vaporizing water, such as heating systems, are well known and may be used in place of ultrasonic oscillators without departing from the scope of the invention.) Nozzles 7203 deliver the steam to an area to receive steam. In some embodiments, an area to receive steam might be the surface or floor that the robotic surface cleaning device is driving and working on. In some embodiments, a mopping cloth 7204 disposed under the nozzles to facilitate mopping or wiping of a work surface. In some embodiments, the nozzles continuously deliver a substantially constant flow of steam to the mopping cloth. In some embodiments, the nozzles periodically deliver predetermined quantities of steam to the cloth. Further details of a steam cleaning apparatus for robotic surface cleaners are provided in U.S. patent application Ser. Nos. 15/432,722 and 16/238,314, the entire contents of which are hereby incorporated by reference.

[0321] In some embodiments, a mopping cloth is detachable from the main body of the robotic surface cleaning device such that the mopping cloth may be removed and washed by a user after it has become soiled. Various securing methods map be used, such as clamp, magnets Velcro, etc. For example, a mopping cloth may be detachable with a portion of the bottom surface of the robot chassis or a component of the robot (e.g., dustbin or fluid reservoir). FIGS. 73A and 73B illustrate an example of a mopping cloth 7300 slidingly coupled to a bottom of a robotic surface cleaner 7301 on a first end. The bottom of robotic surface cleaner 7301 includes a groove 7302 into which a lip 7303 of mopping cloth 7300 may slide. After sliding the first send of mopping cloth 7300 into position on the bottom of the chassis, as shown in FIG. 73A, the opposite end of mopping cloth 7300 may be secured to the bottom of the chassis as well using Velcro or magnets 7304, for example, as illustrated in FIG. 73B. FIGS. 73C-73F illustrate alternative groove and lip configurations for securing the mopping cloth to the bottom of the chassis. In FIGS. 73C-73F the groove 7302 extends inwards towards the chassis. In some embodiments, the mopping cloth includes the groove and the bottom of the chassis of the robot includes the lip. In some embodiments, both sides of the mopping cloth are secured to the bottom of the robot using groove and lip mechanism as described. In some embodiments, the side on which the mopping cloth is secured with the groove and lip mechanism may vary depending on the movement of the robot, and, for example, avoiding Velcro or magnets from detaching. In some embodiments, the groove and lip sliding mechanism may be used on any side of the mopping cloth and more than one groove and lip sliding mechanism may be used. In some embodiments, the positioning of the groove and lip sliding mechanism and the second securing mechanism (item 7304 in FIGS. 73A-73F) may vary depending on, for example, which configuration best secures the mopping cloth to the robot during operation.

[0322] In some embodiments, water is placed within a liquid reservoir of a surface cleaning robot and the water is reacted to produce hydrogen peroxide for cleaning and disinfecting the floor as the robot moves around. In some embodiments, the liquid reservoir may be a part of an extension module, a replacement module, or built into the robot. In some embodiments, the process of water electrolysis may be used to generate the hydrogen peroxide. In some embodiments, the process includes water oxidation over an electrocatalyst in an electrolyte, that results in hydrogen peroxide dissolved in the electrolyte which may be directly applied to the working surface or may be further processed before applying it to the working surface.

[0323] In some embodiments, the wheels of the VMP robot include a wheel suspension system. In some embodiments, the wheel suspension system is a dual suspension system including a first and second suspension system. In some embodiments, the first suspension system includes a wheel coupled to a rotating arm pivotally coupled to a wheel frame. A spring is attached to the rotating arm on one end and the wheel frame on an opposite end. The spring is in an extended state, such that it constantly applies a force to the rotating arm causing the wheel to be pressed against the driving surface as the spring attempts to return to an unstretched state. As the rotating arm with coupled wheel rotates into the wheel frame (e.g., due to an encounter with an obstacle or deformity in the driving surface) the spring is further extended. In some embodiments, the second suspension system includes one or more extension springs vertically positioned between the wheel frame and the chassis of the VMP robot. The wheel frame is slidingly coupled to a base that may be attached to the VMP robot chassis. A first end of the one or more extension springs interfaces with the wheel frame and a second end with the base, such that the one or more extension springs pull the wheel frame and base together as the one or more springs attempt to return to an unstretched state. The wheel frame with coupled rotating arm and wheel can therefore move vertically as the one or more extension springs compress and extend. When the wheel frame, and hence wheel, move vertically upwards the one or more extension springs are further extended. In some embodiments, dampers are positioned along the axis of the one or more extension springs to dissipate energy and provide for a more stable ride. In some embodiments, the spring stiffness of the one or more extension springs is such that the weight of the VMP robot and any additional structures attached thereto can be supported without fill compression of the one or more extension springs. In some embodiments, the second suspension system only allows movement in one direction. In some embodiments, travel limiting screws are coupled to the base to limit the amount of vertical movement. In some embodiments, the one or more extension springs are housed within spring housings. In some embodiments, the first and second suspensions are used independently. An example of a dual wheel suspension system is described in U.S. patent application Ser. Nos. 15/951,096 and 16/270,489, the entire contents of which are hereby incorporated by reference. Other examples of wheel suspension systems that may be used are described in U.S. patent application Ser. Nos. 15/447,450, 15/447,623, and 62/720,521. In some embodiments, one or more wheels of the VMP robot are driven by one or more electric motors. For example, FIG. 74 illustrates a wheel 7400 including wheel gear 7401. Wheel 7400 is driven by one or more output gears 7402 of one or more corresponding electric motors that interface with wheel gear 7401. The processor of the VMP robot may autonomously activate each of the one or more output gears 7402 independently of one another depending on the amount of torque required. For example, the processor may detect an obstacle on the driving surface and may activate all electric motors of the output gears 7402 as a large amount of torque may be required to overcome the obstacle. Output gears 7402 may rotate when deactivated. In other embodiments, any number of output gears interfacing with the wheel gear may be used.

[0324] FIGS. 75A-75C illustrate an example of the first suspension system of the dual suspension system. FIG. 75A illustrates a top perspective view of the first suspension system 7500. FIG. 75B illustrates wheel 7501 in a fully retracted position, with the first suspension system 7500 disengaged and FIG. 75C illustrates wheel 7501 in a fully extended position. Wheel 7501 is coupled to rotating arm 7502 pivotally coupled to wheel frame 7503. Rotating arm 7502 pivots about point 7504. Spring 7505 is anchored to rotating arm 7502 at point 7506 on one end and to wheel frame 7503 on the opposite end. When wheel 7501 is retracted, as in FIG. 75B, spring 7505 is extended. Since spring 7505 is extended in FIG. 75B, spring 7505 pulls on point 7506 of rotating arm 7502, causing it to pivot about point 7504. This causes wheel 7501 to be constantly pressed against the driving surface. When an uneven surface or an obstacle is encountered, first suspension system 7500 is engaged as in FIG. 75C such that the wheel maintains contact with the driving surface. For example, if a hole is encountered, rotating arm 7502 immediately pivots downward due to the force of spring 7505 as it attempts to return to an unstretched state, such that wheel 7501 maintains contact with the driving surface. In some embodiments, the first suspension system is a long-travel suspension system providing, for example, up to approximately 40.0 mm of vertical displacement.

[0325] FIG. 76 illustrates an example of the second suspension system of the dual suspension system. Wheel frame 7503 is slidingly coupled with base 7600. Base 7600 includes a number of mounting elements for mounting to the chassis of the VMP robot. Extension springs 7601 are coupled with base 7600 by bottom anchors 7602a and with wheel frame 7503 by top anchors 7602b. Extension springs 7601 are positioned within spring housings 7603. Dampers 7605 are positioned along the axis of extension springs 7601. Dampers disperse spring energy such that any residual oscillating energy in the suspension springs that may cause the VMP robot to oscillate and vibrate is minimized. Travel limiting screws 7606 are disposed on base 7600. The shaft of travel limiting screws 7606 fit within holes 7607 of wheel frame 7503, however the top of travel limiting screws 7606 are larger than holes 7607, thereby limiting the maximum upward vertical movement as wheel frame 7503 moves relative to base 7600. The tension of extension springs 7601 may be chosen such that the position of frame 7503 along the length of the shaft of travel limiting screws 7606 may provide a desired range of upward and downward vertical movement. When placed on the driving surface, a force substantially equal and opposite to the weight of the VMP robot and any structures attached thereto acts on the wheels, thereby pushing wheel frame 7503 vertically upwards relative to base 7600. Since wheel frame 7503 and base 7600 are mechanically coupled by extension springs 7601, the tension of extension springs 7601 determine the amount by which wheel frame 7503 is pushed upwards. In some embodiments, the maximum upward movement is equal to the maximum downward movement while in other embodiments, the maximum upward movement is greater than the maximum downward movement and vice versa. In some embodiments, the second suspension system is a short-travel suspension system providing, for example, up to approximately 3.0 mm of upward and downward vertical displacement.

[0326] In some embodiments, magnets are used in place of the vertically positioned extension springs of the second suspension. FIG. 77A illustrates an exploded view of an example of the second suspension system where magnets 7700 are used in place of extension spring. FIG. 77B illustrates the second suspension system including base 7600, slidingly coupled with wheel frame 7503, the two attracted to each other by paired magnets 7700. Paired magnets are oriented by opposite poles such that they attract one another. One magnet of the magnet pair 7700 is affixed to wheel frame 7503 while the other magnet of the magnet pair 7700 is affixed to base 7600. Traveling limiting screws 7606 limit the linear separation of wheel frame 7503 and base 7600 as they slide relative to one another. Upon encountering uneven surfaces, such as small bumps or holes, the magnets will separate and pull back together as required, allowing a smoother ride. One or more sets of magnets may be used between wheel frame 7503 and base 7600. For instance, two magnet pairs may be positioned in the rear with one in the front and one on the side. Other variations may also be possible. In one embodiment, each wheel includes three magnet pairs. In yet another embodiment, magnets are used in addition to extension springs in the second suspension system, both having complimentary functionality as when used independently. FIG. 78 illustrates an exploded view of an example of the second suspension system including extension springs 7601 and magnet pair 7700. Extension springs 7601 extend and compress and magnets of magnet pair 7700 come together and pull apart as the VMP robot drives over uneven surfaces, providing a smoother riding experience.

[0327] In some embodiments, the VMP robot (or any other type of robot that implements the methods and techniques described in the disclosure) may include other types of wheel suspension systems. For example, FIGS. 79A and 79B illustrate a wheel suspension system including a wheel 7900 mounted to a wheel frame 7901 slidingly coupled with a chassis 7902 of a robot, a control arm 7903 coupled to the wheel frame 7901, and a torsion spring 7904 positioned between the chassis 7902 and the control arm 7903. Wheel frame 7901 includes coupled pin 7905 that fits within and slides along slot 7906 of chassis 7902. When the robot is on the driving surface, the spring is slightly compressed due to the weight of the robot acting on the torsion spring 7904, and the pin 7905 is positioned halfway along slot 7906, as illustrated in FIGS. 79A and 79B. When the wheel 7900 encounters an obstacle such as a bump, for example, the wheel retracts upwards towards the chassis 7902 causing the torsion spring 7904 to compress and pin 7905 to reach the highest point of slot 7906, as illustrated in FIGS. 79C and 79D. When the wheel 7900 encounters an obstacle such as a hole, for example, the wheel extends downwards away from the chassis 7902 causing the torsion spring 7904 to decompress and pin 7905 to reach the lowest point of slot 7906, as illustrated in FIGS. 79E and 79F. The pin 7905 and the slot 7906 control the maximum vertical displacement of the wheel 7900 in an upwards and downwards direction as slot 7906 prevents pin 7905 attached to wheel frame 7901 with wheel 7900 from physically displacing past its limits. Therefore, the slot may be altered to choose the desired maximum displacement in either direction. Further, torsion springs with different spring stiffness may be chosen, which varies the position of the pin when the robot is on the driving surface and hence the maximum displacement in the upwards and downwards directions. In some embodiments, the wheel suspension system is configured such that displacement may only occur in one direction or displacement occurs in two directions. In some embodiments, the wheel suspension system is configured such that maximum displacement upwards is equal to maximum displacement downwards or such that maximum displacements upwards and downwards are different. FIG. 79G illustrates the wheel suspension during normal driving conditions implemented on a robot.

[0328] In one embodiment, the wheel suspension system is a pivoting suspension system including a wheel coupled to a wheel frame, an actuation spring coupled to the wheel frame on a first end, and a pivoting pin coupled to the wheel frame. The second end of the actuation spring and the pivoting pin are coupled to a top cover of the wheel frame, such that the wheel frame with attached wheel are pivotally coupled to the top cover such that the wheel frame and wheel may pivot from side to side about the pivot pin. In some embodiments, the top cover is or is attached to a chassis of the VMP robot. In some embodiments, the pivoting suspension system is combined with a trailing arm suspension system. FIGS. 80A-80C illustrate an example of a pivoting suspension system including a wheel frame 8000, a wheel 8001 coupled to the wheel frame 8000, a top cover 8002 of the wheel frame 8000, an actuation spring 8003 positioned between the wheel frame 8000 and the top cover 8002, and a pivot pin 8004 that pivotally coupled the wheel frame 8000 to the top cover 8002. FIG. 80B illustrates the wheel 8001 in a normal position. FIG. 80A illustrates the wheel 8001 slightly pivoted towards the left about pivot pin 8004. FIG. 80C illustrates the wheel 8001 slightly pivoted towards the right about pivot pin 8004. FIGS. 81A-81C illustrate a front view of another example of a pivoting wheel suspension including a wheel frame 8100, a wheel module 8101 with attached wheel 8102 pivotally coupled to wheel frame 8100 with pivot pin 8103, and actuation spring 8104 positioned between wheel frame 8100 and wheel module 8101. FIG. 81A illustrates the wheel module 8101 with attached wheel 8102 pivoted towards the right about pivot pin 8103. FIG. 81B illustrates the wheel module 8101 with attached wheel 8102 in a normal position. FIG. 81C illustrates the wheel module 8101 with attached wheel 8102 pivoted towards the left about pivot pin 8103. FIGS.

[0329] In another example, the wheel suspension includes a wheel coupled to a wheel frame. The wheel frame is slidingly coupled to the chassis of the VMP robot. A spring is vertically positioned between the wheel frame and the chassis such that the wheel frame with coupled wheel can move vertically. FIG. 82A illustrates an example of a wheel suspension system with wheel 8200 coupled to wheel frame 8201 and spring 8202 positioned on pin 8203 of wheel frame 8201. FIG. 82B illustrates the wheel suspension integrated with a robot 8204, the wheel frame 8201 slidingly coupled with the chassis of robot 8204. A first end of spring 8202 rests against wheel frame 8201 and a second end against the chassis of robot 8204. Spring 8202 is in a compressed state such that is applies a downward force on wheel frame 8201 causing wheel 8200 to be pressed against the driving surface. FIG. 82C illustrates wheel 8200 after moving vertically upwards (e.g., due to an encounter with an obstacle) with spring 8202 compressed, allowing for the vertical movement. In some embodiments, a second spring is added to the wheel suspension. FIG. 83A illustrates an example of a wheel suspension system with wheel 8300 coupled to wheel frame 8301 and springs 8302 is positioned on respective pins 8303 of wheel frame 8301. FIG. 83B illustrates the wheel suspension integrated with a robot 8304, the wheel frame 8301 slidingly coupled with the chassis of robot 8304. A first end of each spring 8302 rests against wheel frame 8301 and a second end against the chassis of robot 8304. Springs 8302 are in a compressed state such that they apply a downward force on wheel frame 8301 causing wheel 8300 to be pressed against the driving surface. FIG. 83C illustrates wheel 8300 after moving vertically upwards (e.g., due to an encounter with an obstacle) with springs 8302 compressed, allowing for the vertical movement.

[0330] In one example, the wheel suspension includes a wheel coupled to a rotating arm pivotally attached to a chassis of the VMP robot and a spring housing anchored to the rotating arm on a first end and the chassis on a second end. A plunger is attached to the spring housing at the first end and a spring is housed at the opposite end of the spring housing such that the spring is compressed between the plunger and the second end of the spring housing. As the compressed spring constantly attempts to decompress, a constant force is applied to the rotating arm causing it to pivot downwards and the wheel to be pressed against the driving surface. When the wheel retracts (e.g., when encountering a bump in the driving surface), the rotating arm pivots upwards, causing the plunger to further compress the spring. FIGS. 84A and 84B illustrate an example of a wheel suspension including a wheel 8400 coupled to a rotating arm 8401 pivotally attached to a chassis 8402 of a robot and a spring housing 8403 anchored to the rotating arm 8401 on a first end and the chassis 8402 on a second end. A plunger 8404 is rests within the spring housing 8403 of the first end and a spring 8405 is positioned within the spring housing 8403 on the second end. Spring 8405 is compressed by the plunger 8404. As spring 8405 attempts to decompress it causes rotating arm 8401 to pivot in a downwards direction and hence the wheel 8400 to be pressed against the driving surface. FIGS. 84C and 84D illustrate the wheel 8400 retracted. When an obstacle such as a bump is encountered, for example, the wheel 8400 retracts as the rotating arm 8401 pivots in an upwards direction. This causes the spring 8405 to be further compressed by the plunger 8404. After overcoming the obstacle, the decompression of the spring 8405 causes the rotating arm 8401 to pivot in a downwards direction and hence the wheel 8400 to be pressed against the driving surface.

[0331] In yet another example, the wheel suspension includes a wheel coupled to a rotating arm pivotally attached to a chassis of the VMP robot and a spring anchored to the rotating arm on a first end and the chassis on a second end. The spring is in an extended state. As the spring constantly attempts to reach an unstretched state it causes the rotating arm to pivot in a downward direction and the wheel to be therefore pressed against the driving surface. When the wheel encounters an obstacle, the wheel suspension causes the wheel to maintain contact with the driving surface. The further the wheel is extended, the closer the spring is at reaching an unstretched state. FIGS. 85A and 85B illustrate an example of a wheel suspension including a wheel 8500 coupled to a rotating arm 8501 pivotally attached to a chassis 8502 of a robot and a spring 8503 coupled to the rotating arm 8501 on a first end and the chassis 8502 on a second end. The spring 8503 is in an extended state and therefore constantly applies a force to the rotating arm 8501 to pivot in a downward direction as the spring attempts to reach an unstretched state, thereby causing the wheel 8500 to be constantly pressed against the driving surface. When an obstacle, such as a hole, is encountered, for example, the wheel extends as illustrated in FIGS. 85C and 85D. The spring 8503 causes the rotating arm 8501 to rotate further downwards as it attempts to return to an unstretched state. In some embodiments, the springs of the different suspension systems described herein may be replaced by other elastic elements such as rubber. In some embodiments, wheel suspension systems may be used independently or in combination. Additional wheel suspension systems are described in U.S. patent application Ser. Nos. 15/951,096, 16/389,797, and 62/720,521, the entire contents of which are hereby incorporated by reference.

[0332] In one embodiment, the suspension system is a dual suspension system. A first suspension system of the dual suspension system includes a frame, a rotating arm pivotally coupled to the frame, a wheel coupled to the rotating arm, and an extension spring coupled with the rotating arm on a first end and the frame on a second end, wherein the extension spring is extended when the wheel is retracted. The extension spring of the first suspension system applies a force to the rotating arm as the extended extension spring compresses, causing the rotating arm to rotate downwards towards the driving surface such that the wheel coupled to the rotating arm is pressed against the driving surface. The second suspension system of the dual suspension system is a vertical suspension system including a base slidingly coupled with the frame, and a number of vertically positioned extension springs coupled with the frame on a first end and the base on a second end. In some embodiments, the number of extension springs of the second suspension system apply a force to the frame and base, pulling the two components together as the extension springs compress. In some embodiments, extension of the number of extension springs of the second suspension system cause vertical upward movement of the frame, rotating arm, and wheel relative to the base. In some embodiments, compression of the number of extension springs of the second suspension system cause vertical downward movement of the frame, rotating arm, and wheel relative to the base. In some embodiments, the base is fixed to the VMP robot chassis or is part of the VMP robot chassis. In some embodiments, the frame includes a number of spring housings for retaining the number of extension springs from the second suspension system. In some embodiments, the portion of the second suspension system further includes a number of dampers positioned along each axis of each of the number of extension springs. The portion from the second suspension system mitigates the effect of the degree of unevenness of the floor surface such as rates of rise and/or rates of fall of the floor surface. FIGS. 86A and 86B illustrate an example of dual suspension system including the first and second suspension systems as described above when the wheel is extended and retracted, respectively. The first suspension system includes a frame 8600, a rotating arm 8601 pivotally coupled to the frame 8600, a wheel 8602 coupled to the rotating arm 8601, and an extension spring 8603 coupled with the rotating arm 8601 on a first end and the frame 8600 on a second end, wherein the extension spring 8603 is compressed when the wheel is extended beyond the frame (FIG. 86A) and extended when the wheel is retracted towards the frame (FIG. 86B). The second suspension system includes a base 8604 slidingly coupled with the frame 8600, and a set of vertically positioned extension springs 8605 coupled with the frame 8600 on a first end and the base 8604 on a second end. In some embodiments, magnets are used in addition to or instead of extension springs in the second suspension system. In some embodiments, the first and second suspension systems are used independently and in other embodiments, are used in combination. In some embodiments, other types of wheel suspension systems are used.

[0333] In some embodiments, the springs of the different suspension systems described herein may be replaced by other elastic elements such as rubber or with other mechanisms that provide similar function as the springs (e.g., magnets as described above). In some embodiments, the wheels used with the different suspension systems are mecanum wheels, allowing the VMP robot to move in any direction. For example, the VMP robot can travel diagonally by moving a front wheel and opposite rear wheel at one speed while the other wheels turn at a different speed, moving all four wheels in the same direction straight moving, running the wheels on one side in the opposite direction to those on the other side causing rotation, and running the wheels on one diagonal in the opposite direction to those on the other diagonal causes sideways movement. FIGS. 87A and 87B illustrate examples of a mecanum wheel 8700 attached to an arm 8701 of a robotic device. The arm may be coupled to a chassis of the robotic device. FIGS. 88A and 88B illustrate a front and bottom view of an example of a robotic device with mecanum wheels 8800, respectively, that allow the robotic device to move in any direction.

[0334] In some embodiments, the wheels of the VMP robot are also expandable. FIG. 89 illustrates an expandable mecanum wheel 8900 in a contracted position. The expandable wheel comprises: an outer housing 8901 with a plurality of apertures 8902 therein; an inner shaft 8903 co-centered and positioned within an outer shaft 8905 coupled to the outer housing 8901; a plurality of spokes (not shown) mounted pivotally by a first end to the inner shaft; a pivoting linkage (not shown) connected to a second end of the spoke; and a roller 8904 mounted at the distal end of the pivoting linkage so as to be rotatable around an axial of the roller. The inner shaft is positioned within the outer housing in a manner such that it can rotate independently and relative to the outer housing and coupled outer shaft. The inner shaft can be rotated relative to the outer housing and coupled outer shaft, causing the wheel to move from a first position (shown in FIG. 89) in which the linkages and rollers protrude minimally through their corresponding apertures to a second position in which the linkages and rollers protrude maximally through their corresponding apertures. The rollers form the circumference of the wheel, which is smallest in the contracted position and largest in the expanded position. The outer shaft coupled to the outer housing can rotate independently and relative to the inner shaft to rotate the expandable mecanum wheel once positioned at a desired circumference, causing the robot to move. When the inner shaft and the outer housing are caused to rotate relative to one another, the spokes together with the pivoting linkages work as a crank mechanism and translate the relative rotation of the two shafts to a linear movement of the roller radially outward from the center of the wheel, the aperture working as a guide.

[0335] FIG. 90 illustrates the wheel 8900 is shown in the expanded position. The inner shaft 8903 has been rotated relative to the outer housing 8901 and coupled outer shaft 8905, causing the spokes (not illustrated) to move radially outward from the center of the wheel, the apertures 8902 guiding the pivoting linkages and rollers 8904. The rollers 8904 are thus pushed outward from the center of the wheel and form a circumference larger than the circumference formed when the wheel is in the contracted position shown in FIG. 89.

[0336] FIGS. 91A and 91B illustrate cutaway views of the wheel 8900. In both drawings, a singular spoke, linkage, and roller is illustrated in order to portray the parts more clearly, however, in practice, for each aperture 8902, there would be a corresponding spoke, linkage and roller. FIG. 91A illustrates the spoke 9101, linkage 9100 and roller 8904 are in a contracted position. The spoke 9101 is mounted pivotally by a first end to an inner shaft 8903, which is co-centered and positioned within the outer housing 8901 and coupled outer shaft (not shown). As shown in FIG. 91B, rotation of the inner shaft in direction 9102 results in each spoke, linkage, and roller group to be extended in a radially outward direction 9103. When the inner shaft 8903 is rotated in a direction 9102, until a point where each spoke is parallel with a radius of the inner shaft 8903, the linkage and roller are pushed at a maximal distance from the center of the wheel, creating a larger circumference. Sleeve 9104 fits over the aperture structures of outer housing 8901 to protect apertures 8902 from wear. In some embodiments, the sleeve is provided around the aperture to limit the wear of the link member and to provide better support for the link member as a guide.

[0337] In alternative embodiments, either the inner or the outer shaft may be connected to a means for rotating them and could rotate relative to the other one. In some embodiments, separate motors are used to rotate the inner shaft and the outer shaft. Rotation of the inner shaft increases or decreases the circumference of the wheel by extension and retraction of the rollers. Rotation of the outer shaft rotates the expandable mecanum wheel, causing the robot to move. In some embodiments, the same motor is used to expand and retract the wheel and to rotate the wheel.

[0338] In some embodiments, the processor of the VMP robot uses sensors to detect conditions used to determine when the wheels should be expanded or retracted. For example, data of a sensor monitoring tension on wheels may be used to determine when to expand the wheel, when, for example, more than a predetermined amount of tension is detected. In another example, the current drawn by the motor of the wheel may be used to indicate tension in rotation of the wheel when the current drawn by the motor is increased while trying to maintain the same wheel speed. Similarly, data of a sensor monitoring rate of rotation of a wheel may be used to determine when to expand the wheel, when, for example, it is determined that rotation is not concurrent with motor power. It will be obvious to one skilled in the art that the disclosed invention can benefit from any kind of sensing mechanism to detect tension etc. Further examples of expandable mecanum wheels are described in U.S. patent application Ser. Nos. 15/447,450 and 15/447,623, the entire contents of which are hereby incorporated by reference.

[0339] In some embodiments, the wheel motor is positioned within a wheel of the VMP robot. For example, FIGS. 92A and 92B illustrate a wheel with a brushless DC motor positioned within the wheel. FIG. 92A illustrates an exploded view of the wheel with motor including a rotor 9200 with magnets 9201, a bearing 9202, a stator 9203 with coil sets 9204, 9205, and 9206, an axle 9207 and tire 9208 each attached to rotor 9200. Each coil set (9204, 9205, and 9206) include three separate coils, the three separate coils within each coil set being every third coil. The rotor 9200 acts as a permanent magnet. DC current is applied to a first set of coils 9204 causing the coils to energize and become an electromagnet. Due to the force interaction between the permanent magnet (i.e., the rotor 9200) and the electromagnet (i.e., the first set of coils 9204 of stator 9203), the opposite poles of the rotor 9200 and stator 9203 are attracted to each other, causing the rotor to rotate towards the first set of coils 9204. As the opposite poles of rotor 9200 approach the first set of coils 9204, the second set of coils 9205 are energized and so on, and so forth, causing the rotor to continuously rotate due to the magnetic attraction. Once the rotor 9200 is about to reach the first coil set 9204 a second time, the first coil set 9204 is energized again but with opposite polarity as the rotor has rotated 180 degrees. In some embodiments, the set of coils immediately following the set of coils being energized are energized as well to increase the torque. FIG. 92B illustrates a top perspective view of the constructed wheel with the motor positioned within the wheel. In some embodiments, the processor uses data of a wheel sensor (e.g., halls effect sensor) to determine the position of the rotor, and based on the position determines which pairs of coils to energize.

[0340] In some embodiments, the VMP robot, including any of its add-on structures, includes one or more sensor arrays. In some embodiments, a sensor array includes a flexible or rigid material (e.g., plastic or other type of material in other instances) with connectors for sensors (different or the same). In some embodiments, the sensor array is a flexible plastic with connected sensors. In some embodiments, a flexible (or rigid) isolation component is included in the sensor array. The isolation piece is meant to separate sensor sender and receiver components of the sensor array from each other to prevent a reflection of an incorrect signal from being received and a signal from being unintentionally rebounded off of the VMP robot rather than objects within the environment. In some embodiments, the isolation component separates two or more sensors. In some embodiments, the isolation component includes two or more openings, each of which is to house a sensor. In some embodiments, the sizes of the openings are the same. In alternative embodiments, the sizes of the openings are of various sizes. In some embodiments, the openings are of the same shape. In alternative embodiments, the openings are of various shapes. In some embodiments, a wall is used to isolate sensors from one another. In some embodiments, multiple isolation components are included on a single sensor array. In some embodiments, the isolation component is provided separate from sensor array. In some embodiments, the isolation component is rubber, Styrofoam, or another material and is placed in strategic locations in order to minimize the effect on the field of view of the sensors. In some embodiments, the sensors array is positioned around the perimeter of the VMP robot shell. In some embodiments, the sensor array is placed internal to an outer shell of the VMP robot. In alternative embodiments, the sensor array is located on the external body of the VMP robot. FIG. 93A illustrates an example of a sensor array including a flexible material 9300 with sensors 9301 (e.g., LED and receiver). FIG. 93B illustrates the fields of view 9302 of sensors 9301. FIG. 93C illustrates the sensor array mounted around the perimeter of a chassis 9303 of a robotic device, with sensors 9301 and isolation components 9304. FIG. 93D illustrates one of the isolation components 9304 including openings 9305 for sensors 9301 (shown in FIG. 93C) and wall 9306 for separating the sensors 9301.

[0341] In some embodiments, sensors of the VMP robot are positioned such that the field of view of the VMP robot is maximized while cross-talk between sensors is minimized. In some embodiments, sensor placement is such that the IR sensor blind spots along the perimeter of the VMP robot in a horizontal plane (perimeter perspective) are minimized while at the same time eliminating or reducing cross talk between sensors by placing them far enough from one another. In some embodiments, an obstacle sensor (e.g., IR sensor, TOF sensor, TSSP sensor, etc.) is positioned along the front of the robot at the midpoint such that the vertical blind spot of the VMP robot is minimized and such that the VMP robot is intentionally blind to objects below a predetermined height relative to the driving surface. For example, the VMP robot is blind to obstacles of certain size. In some embodiments, the predetermined height, below which the VMP robot is blind, is smaller or equal to the height the VMP robot is physically capable of climbing. This means that, for example, if the wheels (and suspension) are capable of climbing over objects 20 mm in height, the obstacle sensor should be positioned such that it can only detect obstacles equal to or greater than 20 mm in height. In some embodiments, a buffer is implemented and the predetermined height, below which the VMP robot is blind, is smaller or equal to some percentage of the height the VMP robot is physically capable of climbing (e.g., 80%, 90%, or 98% of the height the VMP robot is physically capable of climbing). The buffer increases the likelihood of the VMP robot succeeding at climbing over an obstacle if the processor decides to execute a climbing action. In some embodiments, at least one obstacle sensor (e.g., IR sensor, TOF sensor, TSSP sensor, etc.) is positioned in the front and on the side of the VMP robot. In some embodiments, the obstacle sensor positioned on the side is positioned such that the data collected by the sensor can be used by the processor to execute accurate and straight wall following by the VMP robot. In alternative embodiments, at least one obstacle sensor is positioned in the front and on either side of the VMP robot. In some embodiments, the obstacle sensor positioned on the side is positioned such that the data collected by the sensor can be used by the processor to execute accurate and straight wall following by the VMP robot. FIG. 93E illustrates an example of a sensor array showing the positioning and field of view of ten TSSP sensors, four presence LED sensors (e.g., IR transmitter), and three time-of-flight sensors. The position of the sensors allows for maximum combined field of view with minimal cross-talk among adjacent sensors. In some embodiments, TSSP sensors have an opening angle of 120 degrees and a depth of 3 to 5 cm, TOF sensors have an opening angle of 25 degrees and a depth of 40 to 45 cm, presence LED sensors have an opening angle of 120 degrees and a depth 50 to 55 cm. Further details of a sensor array are described in U.S. Patent Application No. 62/720,478, the entire contents of which is hereby incorporated by reference.

[0342] In some embodiments, the VMP robot may further include movement sensors, such as an odometer, inertial measurement units (like with a three axis accelerometer and a three axis gyroscope), and/or optical flow sensor (e.g., a visual odometry sensor facing the ground), and the like. In other embodiments, structure from motion techniques may be implemented to measure movement. A gyroscope sensor, for example, includes a small resonating mass that shifts when rotation is initiated or speed of rotation changes. The movement of the mass induces an electrical signal that may be read by a controller and converted or other processing module into an angular velocity or other measurements indicating speed, acceleration, and/or direction of movement. In further embodiments, the gyroscope sensor may be used to measure rotational movement. An odometer sensor, for example, may determine the distance (or path, e.g., in vector form with both distance and direction) travelled by counting the number of wheel rotations. Given the diameter of the wheel, the distance travelled can be calculated. An odometer can therefore be used to measure translational or rotational movement. In some embodiments, optical flow and structure from motion techniques measure movement using images and/or data derived from images. Motion may be estimated based on changes in the features, such as lighting, of consecutive images captured as the camera moves relative to objects in the environment.

[0343] In some embodiments, the VMP robot includes edge detection sensors to avoid cliffs and drop-offs. Examples of edge detection sensors are disclosed in U.S. patent application Ser. Nos. 14/941,385, 16/279,699, and 16/041,470, the entire contents of which are hereby incorporated by reference. In some embodiments, one or more rangefinder sensors may be positioned on the underside of a VMP robot such that emitted signals are directed downward. In some embodiments, one or more rangefinders are positioned on other portions of the VMP robot. For example, one or more rangefinders can be positioned on a side, front, and underside of the VMP robot. In some embodiments, some of the rangefinders are positioned on a side of the VMP robot and others are positioned on an underside. Any available type of rangefinder sensor may be employed, including laser rangefinder sensors, infrared rangefinder sensors, or ultrasonic rangefinder sensors. Generally, rangefinder sensors simultaneously emit a signal and start a timer. When the signal reaches an obstacle, it bounces off and, in a second step, reflects back into a receiver. Receipt of a reflected signal stops the timer. Because the signals travel at a constant rate, the time elapsed between when a signal is sent and when it is received may be used to calculate the distance that the signal traveled, and, thus, the distance from the sensor to the reflecting surface. In some embodiments, the one or more rangefinder sensors calculate the distance from their location to the nearest surface in their line of sight. On uniform flat surfaces, this distance, representing the distance from the bottom of the device to the work surface, is expected to remain substantially constant. Upon encountering a drop-off or cliff, the rangefinder sensors will detect a sudden increase in the distance to the nearest surface. A distance increase beyond a predetermined threshold may actuate the VMP robot's methods for avoiding the area, which may include reversing, turning away, or other methods.

[0344] FIG. 94 illustrates an overhead view of the underside of an example of a robotic vacuum 9400 with a set of rangefinder sensors 9401 installed along a portion of the periphery thereof. A robotic vacuum may also include driving wheels 9402, a front wheel 9403 for steering, and a cleaning apparatus 9404. The positioning of rangefinder sensors may vary, however, in the preferred embodiment, rangefinder sensors are positioned substantially around a portion of (or all of) the periphery of the underside of the particular device in question so that, as the device is traveling in a forward direction, the rangefinder sensors may detect an edge before either any wheels of the device have traversed the edge or the center of mass of the device has passed the edge. FIG. 95A illustrates a side elevation view of the robotic vacuum 9400 using rangefinder sensors 9401 over a surface 9505 with no edges. The rangefinder sensors 9401 continuously calculate the distance 9506 from their location to the nearest surface, which is typically the work surface 205. (The nearest surface could be an item positioned on top of the work surface that the device has driven over.) The rangefinder sensors are electrically coupled with a processor of the device (not shown), which monitors the calculated distances. Positive changes in the distance greater than a predetermined amount may trigger the methods and algorithms for avoiding an area. Methods for avoiding areas include methods or algorithms employed to drive the robot away from a particular area. These methods may include turning 360 degrees and driving in the opposite direction, reversing, turning a small amount and then continuing, etc. In the example shown in FIG. 95A, no positive change is detected (indicating that no edges have been identified) and the device continues operation as normal. FIG. 95B illustrates a side elevation view of the robotic vacuum 9400 using rangefinder sensors 9401 over a surface 9507 with an edge 9508. In this case, the robotic vacuum has moved in a direction 9509 to arrive at the current location where the distance 9510 from the rangefinder sensor 9401 to the nearest surface 9511 is significantly greater than before. The increase in distance may be greater than a predetermined amount and trigger the methods for avoiding the area, thereby stopping the device from falling off the edge. In some embodiments, program code stored in the memory and executed by the processor of the VMP robot may effectuate the operations described herein.

[0345] In some embodiments, rangefinders are positioned on one or more portions of the VMP robot. For example, FIG. 96 illustrates a side view of an example of a robotic vacuum with rangefinder 9600 positioned on a front side of the robotic vacuum. Rangefinder 9600 measures distances to surface 9601 as the robotic device approaches cliff 9602. A processor of the robotic vacuum detects cliff 9602 by detecting an increase in distances measured by rangefinder 9600. FIG. 97 illustrates a front view of an example of a robotic vacuum with rangefinders 9700, 9701, and 9702 positioned on a bottom side and 9704 on a front side of the robotic vacuum. Rangefinders 9700, 9701, 9702, and 9704 measure distances to surface 9705. FIG. 98 illustrates a top view of an example of a robotic vacuum with rangefinders 9800, 9801, 9802, 9803, 9805, and 9805 positioned on a front, side, and bottom of the robotic vacuum. FIG. 99 illustrates a side view of an example of a robotic vacuum with LIDAR 9900 on a front side of the robotic vacuum. LIDAR 9900 measures distances to surface 9901 in three dimensions as the robotic device approaches cliff 9902. In embodiments, different arrangements of rangefinders and LIDAR systems (or otherwise distance sensors or detection systems) are possible.

[0346] In some embodiments, the processor uses sensor data to distinguish between dark surfaces (e.g., dark flooring, surface cracks, etc.) and cliffs. In some embodiments, the processor uses the amplitude of output data of a TOF sensor predict whether a dark surface or cliff is observed as the amplitude may correlate with reflectivity of a surface. In some embodiments, the amplitude of the output data of a TOF sensor is different when the area observed by the TOF sensor is a close, dark surface (e.g., dark carpet) as compared to when the area observed by the TOF sensor is a far surface, as is the case when the area observed by the TOF sensor is a cliff. In some embodiments, the processor uses this approach to distinguish between different types of other surfaces.

[0347] In some embodiments, the VMP robot (or any of its structures) includes various sensors for observing the surroundings. For example, in some embodiments, the VMP robot may include an on-board camera, such as one with zero-degrees of freedom of actuated movement relative to the VMP robot (which may itself have three degrees of freedom relative to a working environment), or some embodiments may have more or fewer degrees of freedom; e.g., in some cases, the camera may scan back and forth relative to the VMP robot. Such cameras may include, but are not limited to, depth cameras, such as stereo or structured light depth cameras, stereo vision cameras, or various other types of camera producing output data from which the environment may be perceived. In some embodiments, a time-of-flight camera may determine distance based on time required for light transmitted from the VMP robot to reflect off of an object and return to the camera, from which distance to the object can be inferred. Distance measurements to objects may also be estimated (or otherwise perceived) by capturing images of the objects from a moving camera, e.g., with structure from motion techniques. Distance may also be measured using a combination of one or more lasers, one or more cameras, and one or more image processors (or the main processor of the robot). (Modular Robot) Other depth perceiving devices that collect data from which depth may be inferred may be used. For example, in one embodiment the depth perceiving device may capture depth images containing depth vectors to objects, from which the processor can calculate the Euclidean norm of each vector, representing the depth from the camera to objects within the field of view of the camera. In some instances, depth vectors originate at the depth perceiving device and are measured in a two-dimensional plane coinciding with the line of sight of the depth perceiving device. In other instances, a field of three-dimensional vectors originating at the depth perceiving device and arrayed over objects in the environment are measured. In a further example, depth to objects may be inferred using the quality of pixels, such as brightness, intensity, and color, in captured images of the objects, and in some cases, parallax and scaling differences between images captured at different camera poses.

[0348] For example, a depth perceiving device may include a laser light emitter disposed on a baseplate emitting a collimated laser beam creating a projected light point on surfaces substantially opposite the emitter, two image sensors disposed on the baseplate, positioned at a slight inward angle towards to the laser light emitter such that the fields of view of the two image sensors overlap and capture the projected light point within a predetermined range of distances, the image sensors simultaneously and iteratively capturing images, and an image processor overlaying the images taken by the two image sensors to produce a superimposed image showing the light points from both images in a single image, extracting a distance between the light points in the superimposed image, and, comparing the distance to figures in a preconfigured table that relates distances between light points with distances between the baseplate and surfaces upon which the light point is projected (which may be referred to as ‘projection surfaces’ herein) to find an estimated distance between the baseplate and the projection surface at the time the images of the projected light point were captured. In some embodiments, the preconfigured table may be constructed from actual measurements of distances between the light points in superimposed images at increments in a predetermined range of distances between the baseplate and the projection surface.

[0349] FIGS. 100A and 100B illustrates a front elevation and top plan view of an embodiment of the depth perceiving device 10000 including baseplate 10001, left image sensor 10002, right image sensor 10003, laser light emitter 10004, and image processor 10005. The image sensors are positioned with a slight inward angle with respect to the laser light emitter. This angle causes the fields of view of the image sensors to overlap. The positioning of the image sensors is also such that the fields of view of both image sensors will capture laser projections of the laser light emitter within a predetermined range of distances. FIG. 101 illustrates an overhead view of depth perceiving device 10000 including baseplate 10001, image sensors 10002 and 10003, laser light emitter 10004, and image processor 10005. Laser light emitter 10004 is disposed on baseplate 10001 and emits collimated laser light beam 10100. Image processor 10005 is located within baseplate 10001. Area 10101 and 10102 together represent the field of view of image sensor 10002. Dashed line 10105 represents the outer limit of the field of view of image sensor 10002 (it should be noted that this outer limit would continue on linearly, but has been cropped to fit on the drawing page). Area 10103 and 10102 together represent the field of view of image sensor 10003. Dashed line 10106 represents the outer limit of the field of view of image sensor 10003 (it should be noted that this outer limit would continue on linearly, but has been cropped to fit on the drawing page). Area 10102 is the area where the fields of view of both image sensors overlap. Line 10104 represents the projection surface. That is, the surface onto which the laser light beam is projected.

[0350] In some embodiments, each image taken by the two image sensors shows the field of view including the light point created by the collimated laser beam. At each discrete time interval, the image pairs are overlaid creating a superimposed image showing the light point as it is viewed by each image sensor. Because the image sensors are at different locations, the light point will appear at a different spot within the image frame in the two images. Thus, when the images are overlaid, the resulting superimposed image will show two light points until such a time as the light points coincide. The distance between the light points is extracted by the image processor using computer vision technology, or any other type of technology known in the art. This distance is then compared to figures in a preconfigured table that relates distances between light points with distances between the baseplate and projection surfaces to find an estimated distance between the baseplate and the projection surface at the time that the images were captured. As the distance to the surface decreases the distance measured between the light point captured in each image when the images are superimposed decreases as well. In some embodiments, the emitted laser point captured in an image is detected by the image processor by identifying pixels with high brightness, as the area on which the laser light is emitted has increased brightness. After superimposing both images, the distance between the pixels with high brightness, corresponding to the emitted laser point captured in each image, is determined.

[0351] FIG. 102A illustrates an embodiment of the image captured by left image sensor 10002. Rectangle 10200 represents the field of view of image sensor 10002. Point 10201 represents the light point projected by laser beam emitter 10004 as viewed by image sensor 10002. FIG. 102B illustrates an embodiment of the image captured by right image sensor 10003. Rectangle 10202 represents the field of view of image sensor 10003. Point 10203 represents the light point projected by laser beam emitter 10004 as viewed by image sensor 10002. As the distance of the baseplate to projection surfaces increases, light points 10201 and 10203 in each field of view will appear further and further toward the outer limits of each field of view, shown respectively in FIG. 101 as dashed lines 10105 and 10106. Thus, when two images captured at the same time are overlaid, the distance between the two points will increase as distance to the projection surface increases. FIG. 102C illustrates the two images of FIG. 102A and FIG. 102B overlaid. Point 10201 is located a distance 10204 from point 10203, the distance extracted by the image processor 10005. The distance 10204 is then compared to figures in a preconfigured table that co-relates distances between light points in the superimposed image with distances between the baseplate and projection surfaces to find an estimate of the actual distance from the baseplate to the projection surface upon which the laser light was projected.

[0352] In some embodiments, the two image sensors are aimed directly forward without being angled towards or away from the laser light emitter. When image sensors are aimed directly forward without any angle, the range of distances for which the two fields of view may capture the projected laser point is reduced. In these cases, the minimum distance that may be measured is increased, reducing the range of distances that may be measured. In contrast, when image sensors are angled inwards towards the laser light emitter, the projected light point may be captured by both image sensors at smaller distances from the obstacle.

[0353] In some embodiments, the image sensors may be positioned at an angle such that the light point captured in each image coincides at or before the maximum effective distance of the distance sensor, which is determined by the strength and type of the laser emitter and the specifications of the image sensor used.

[0354] In some embodiments, the depth perceiving device further includes a plate positioned in front of the laser light emitter with two slits through which the emitted light may pass. In some instances, the two image sensors may be positioned on either side of the laser light emitter pointed directly forward or may be positioned at an inwards angle towards one another to have a smaller minimum distance to the object that may be measured. The two slits through which the light may pass results in a pattern of spaced rectangles. In some embodiments, the images captured by each image sensor may be superimposed and the distance between the rectangles captured in the two images may be used to estimate the distance to the projection surface using a preconfigured table relating distance between rectangles to distance from the surface upon which the rectangles are projected. The preconfigured table may be constructed by measuring the distance between rectangles captured in each image when superimposed at incremental distances from the surface upon which they are projected for a range of distances.

[0355] In some instances, a line laser is used in place of a point laser. In such instances, the images taken by each image sensor are superimposed and the distance between coinciding points along the length of the projected line in each image may be used to determine the distance from the surface using a preconfigured table relating the distance between points in the superimposed image to distance from the surface. In some embodiments, the depth perceiving device further includes a lens positioned in front of the laser light emitter that projects a horizontal laser line at an angle with respect to the line of emission of the laser light emitter. The images taken by each image sensor may be superimposed and the distance between coinciding points along the length of the projected line in each image may be used to determine the distance from the surface using a preconfigured table as described above. The position of the projected laser line relative to the top or bottom edge of the captured image may also be used to estimate the distance to the surface upon which the laser light is projected, with lines positioned higher relative to the bottom edge indicating a closer distance to the surface. In some embodiments, the position of the laser line may be compared to a preconfigured table relating the position of the laser line to distance from the surface upon which the light is projected. In some embodiments, both the distance between coinciding points in the superimposed image and the position of the line are used in combination for estimating the distance to the projection surface. In combining more than one method, the accuracy, range, and resolution may be improved.

[0356] FIG. 103A illustrates an embodiment of a side view of a depth perceiving device including a laser light emitter and lens 10300, image sensors 10301, and image processor (not shown). The lens is used to project a horizontal laser line at a downwards angle 10302 with respect to line of emission of laser light emitter 10303 onto object surface 10304 located a distance 10305 from the depth perceiving device. The projected horizontal laser line appears at a height 10306 from the bottom surface. As shown, the projected horizontal line appears at a height 10307 on object surface 10308, at a closer distance 10309 to laser light emitter 10300, as compared to object 10304 located a further distance away. Accordingly, in some embodiments, in a captured image of the projected horizontal laser line, the position of the line from the bottom edge of the image would be higher for objects closer to the distance estimation system. Hence, the position of the project laser line relative to the bottom edge of a captured image may be related to the distance from the surface. FIG. 103B illustrates a top view of the depth perceiving device including laser light emitter and lens 10300, image sensors 10301, and image processor 10310. Horizontal laser line 10311 is projected onto object surface 10306 located a distance 10305 from the baseplate of the distance measuring system. FIG. 103C illustrates images of the projected laser line captured by image sensors 10301. The horizontal laser line captured in image 10312 by the left image sensor has endpoints 10313 and 10314 while the horizontal laser line captured in image 10315 by the right image sensor has endpoints 10316 and 10317. FIG. 103C illustrates images of the projected laser line captured by image sensors 10301. The horizontal laser line captured in image 10312 by the left image sensor has endpoints 10313 and 10314 while the horizontal laser line captured in image 10315 by the right image sensor has endpoints 10316 and 10317. FIG. 103C also illustrates the superimposed image 10318 of images 10312 and 10315. On the superimposed image, distances 10319 and 10320 between coinciding endpoints 10316 and 10313 and 10317 and 10314, respectively, along the length of the laser line captured by each camera may be used to estimate distance from the baseplate to the object surface. In some embodiments, more than two points along the length of the horizontal line may be used to estimate the distance to the surface. In some embodiments, the position of the horizontal line 10321 from the bottom edge of the image may be simultaneously used to estimate the distance to the object surface as described above. In some configurations, the laser emitter and lens may be positioned below the image sensors, with the horizontal laser line projected at an upwards angle with respect to the line of emission of the laser light emitter. In one embodiment, a horizontal line laser is used rather than a laser beam with added lens. In some embodiments, a laser line is formed from a series of light points. Other variations in the configuration are similarly possible. For example, the image sensors may both be positioned to the right or left of the laser light emitter as opposed to either side of the light emitter as illustrated in the examples.

[0357] In some embodiments, noise, such as sunlight, may cause interference causing the image processor to incorrectly identify light other than the laser as the projected laser line in the captured image. The expected width of the laser line at a particular distance may be used to eliminate sunlight noise. A preconfigured table of laser line width corresponding to a range of distances may be constructed, the width of the laser line increasing as the distance to the obstacle upon which the laser light is projected decreases. In cases where the image processor detects more than one laser line in an image, the corresponding distance of both laser lines is determined. To establish which of the two is the true laser line, the image processor compares the width of both laser lines and compares them to the expected laser line width corresponding to the distance to the object determined based on position of the laser line. In some embodiments, any hypothesized laser line that does not have correct corresponding laser line width, to within a threshold, is discarded, leaving only the true laser line. In some embodiments, the laser line width may be determined by the width of pixels with high brightness. The width may be based on the average of multiple measurements along the length of the laser line.

[0358] In some embodiments, noise, such as sunlight, which may be misconstrued as the projected laser line, may be eliminated by detecting discontinuities in the brightness of pixels corresponding to the hypothesized laser line. For example, if there are two hypothesized laser lines detected in an image, the hypothesized laser line with discontinuity in pixel brightness, where for instance pixels 1 to 10 have high brightness, pixels 11-15 have significantly lower brightness and pixels 16-25 have high brightness, is eliminated as the laser line projected is continuous and, as such, large change in pixel brightness along the length of the line are unexpected. These methods for eliminating sunlight noise may be used independently, in combination with each other, or in combination with other methods during processing. For example, in some embodiments, an IR receiver may distinguish a true IR signal from sunlight by detection of a unique pattern encoded in the IR signal. In some embodiments, the transmitted signal of the IR sensor is modified to include a unique pattern which the IR receiver may use to distinguish the true IR signal from sunlight, thereby avoiding false detection of signals.

[0359] In another example, a depth perceiving device includes an image sensor, an image processor, and at least two laser emitters positioned at an angle such that they converge. The laser emitters project light points onto an object, which is captured by the image sensor. The image processor may extract geometric measurements and compare the geometric measurement to a preconfigured table that relates the geometric measurements with depth to the object onto which the light points are projected. In cases where only two light emitters are used, they may be positioned on a planar line and for three or more laser emitters, the emitters are positioned at the vertices of a geometrical shape. For example, three emitters may be positioned at vertices of a triangle or four emitters at the vertices of a quadrilateral. This may be extended to any number of emitters. In these cases, emitters are angled such that they converge at a particular distance. For example, for two emitters, the distance between the two points may be used as the geometric measurement. For three of more emitters, the image processer measures the distance between the laser points (vertices of the polygon) in the captured image and calculates the area of the projected polygon. The distance between laser points and/or area may be used as the geometric measurement. The preconfigured table may be constructed from actual geometric measurements taken at incremental distances from the object onto which the light is projected within a specified range of distances. Regardless of the number of laser emitters used, they shall be positioned such that the emissions coincide at or before the maximum effective distance of the depth perceiving device, which is determined by the strength and type of laser emitters and the specifications of the image sensor used. Since the laser light emitters are angled toward one another such that they converge at some distance, the distance between projected laser points or the polygon area with projected laser points as vertices decrease as the distance from the surface onto which the light is projected increases. As the distance from the surface onto which the light is projected increases the collimated laser beams coincide and the distance between laser points or the area of the polygon becomes null. FIG. 104 illustrates a front elevation view of a depth perceiving device 10400 including a baseplate 10401 on which laser emitters 10402 and an image sensor 10403 are mounted. The laser emitters 10402 are positioned at the vertices of a polygon (or endpoints of a line, in cases of only two laser emitters). In this case, the laser emitters are positioned at the vertices of a triangle 10404. FIG. 105 illustrates the depth perceiving device 10400 projecting collimated laser beams 10505 of laser emitters 10402 (not shown) onto a surface 10501. The baseplate 10401 and laser emitters (not shown) are facing a surface 10501. The dotted lines 10505 represent the laser beams. The beams are projected onto surface 10501, creating the light points 10502, which, if connected by lines, form triangle 10500. The image sensor (not shown) captures an image of the projection and sends it to the image processing unit (not shown). The image processing unit extracts the triangle shape by connecting the vertices to form triangle 10500 using computer vision technology, finds the lengths of the sides of the triangle, and uses those lengths to calculate the area within the triangle. The image processor then consults a pre-configured area-to-distance table with the calculated area to find the corresponding distance.

[0360] In some embodiments, a second image sensor is included to improve accuracy of the depth perceiving device. FIG. 106 illustrates a front elevation view of an example of a depth perceiving device 10600 including a baseplate 10601, image sensors 10602, laser light emitters 10603, and image processors 10604. The laser light emitters 10603 are positioned with a slight inward angle toward each other, with the point of convergence being a predetermined distance from the baseplate. The one or more image sensors shall be positioned such that the fields of view thereof will capture laser projections of the laser light emitters within a predetermined range of distances. FIG. 107 illustrates an overhead view of the depth perceiving device. Laser light emitters 10603 are disposed on baseplate 10601 and emit collimated laser light beams 10700, which converge at point 10701. Image sensors 10602 are located on either side of the laser light emitters. Image processor 10604 is located within baseplate 10601. In some embodiments, the maximum effective distance of the depth perceiving device is at the point where the laser beams coincide. In other embodiments, using different wavelengths in each laser light emitter will allow the image processor to recognize the distances between the light points after the point of convergence as being further from the baseplate than the identical distances between the light points that will occur before the point of convergence. In distances beyond point 10701, the laser beam from the right-most laser emitter will appear on the left side, and the laser beam from the left-most laser emitter will appear on the right side. Upon identifying the switch in locations of the laser beams, the image processor will determine that the extracted distance is occurring after the point of convergence.

[0361] In some embodiments, the one or more image sensors simultaneously and iteratively capture images at discrete time intervals. FIG. 108 illustrates an image 10800 captured by image sensor 10602. Rectangle 10801 represents the field of view of image sensor 10602. Points 10802 and 10803 represent the light points projected by the laser light emitters 10603. As the distance of the baseplate to projection surfaces increases, the light points 10802, 10803 will appear closer and closer together until the distance between them is null, after which point the light points will diverge from each other. Thus, the distance 10804 between the two points may be analyzed to determine the distance to the projection surface at the time that an image is captured. The image 10801 is sent to the image processor, which extracts the distance 10804 between the two points (if any). The distance 10804 is then compared to figures in a preconfigured table that co-relates distances between light points in the system with distances between the baseplate and projection surfaces to find an estimate of the actual distance from the baseplate to the projection surface at the time the image of the laser light projections was captured. In some embodiments, the process of capturing an image, sending it to an image processor, and extracting the distance between the light points is performed simultaneously using a second image sensor, and the data extracted from images from the first image sensor is combined with the data extracted from the second image sensor to obtain a more accurate aggregate reading before consulting the preconfigured table.

[0362] Other configurations of the laser light emitters are possible. For example, in FIG. 109A a depth perceiving device 10900 includes laser light emitters 10903 positioned at different heights on the baseplate 10901, image sensors 10902 and image processor 10904. The laser beams will still converge, but the light points will move in a vertical plane in addition to a horizontal plane of captured images as the distance to the projection surface changes. This additional data will serve to make the system more accurate. FIG. 109B illustrates a side view of the depth perceiving device 10900 wherein the laser beam emissions 10905 can be seen converging in a vertical plane. In another example, in FIG. 110A a depth perceiving device 11000 includes laser light emitters 11003 positioned on baseplate 11001 at a downward angle with respect to a horizontal plane, image sensors 11002, and image processor 11004. The laser beams will still converge, but, in a similar manner as previously described, the light points will move in a vertical plane in addition to a horizontal plane of the image as the distance to the projection surface changes. FIG. 110B illustrates a side view of the depth perceiving device 11000, wherein the laser beam emissions 11005 can be seen angled downward. FIG. 111 illustrates various different configurations of a depth perceiving device in terms of positioning of components and types of components included, such as laser emitter 11100, camera 11101, TOF sensor 11102, and a gyroscope 11103. Combinations including laser emitter 11100 and camera(s) 11101 may be used to estimate depth using methods such as those described above. Combinations including two cameras 11101 and a laser emitter 11100 may improve accuracy as two cameras capture images of the environment. Camera 11101 and TOF sensor 11102 or the camera 11101 and gyroscope 11103 combinations may each be used to estimate depth, the two methods increasing the accuracy and/or confidence of measured depth when used in combination as two different data sources are used in measuring depth.

[0363] In some embodiments, ambient light may be differentiated from illumination of a laser in captured images by using an illuminator which blinks at a set speed such that a known sequence of images with and without the illumination is produced. For example, if the illuminator is set to blink at half the speed of the frame rate of a camera to which it is synched, the images captured by the camera produce a sequence of images wherein only every other image contains the illumination. This technique allows the illumination to be identified as the ambient light would be present in each captured image or would not be contained in the images in a similar sequence as to that of the illumination. In embodiments, more complex sequences may be used. For example, a sequence wherein two images contain the illumination, followed by three images without the illumination and then one image with the illumination may be used. A sequence with greater complexity reduces the likelihood of confusing ambient light with the illumination. This method of eliminating ambient light may be used independently, or in combination with other methods for eliminating sunlight noise. For example, in some embodiments, the depth perceiving device further includes a band-pass filter to limit the allowable light.

[0364] Traditional spherical camera lenses are often affected by spherical aberration, an optical effect that causes light rays to focus at different points when forming an image, thereby degrading image quality. In cases where, for example, the distance is estimated based on the position of a projected laser point or line, image resolution is important. To compensate for this, in some embodiments, a camera lens with uneven curvature may be used to focus the light rays at a single point. Further, with traditional spherical camera lens, the frame will have variant resolution across it, the resolution being different for near and far objects. To compensate for this uneven resolution, in some embodiments, a lens with aspherical curvature may be positioned in front of the camera to achieve uniform focus and even resolution for near and far objects captured in the frame. In some embodiments both cameras (or otherwise imaging sensors of the depth perceiving device) are placed behind a single camera lens.

[0365] In some embodiments, two-dimensional imaging sensors may be used. In other embodiments, one-dimensional imaging sensors may be used. In some embodiments, one-dimensional imaging sensors may be combined to achieve readings in more dimensions. For example, to achieve similar results as two-dimensional imaging sensors, two one-dimensional imaging sensors may be positioned perpendicularly to one another. In some instances, one-dimensional and two-dimensional imaging sensors may be used together.

[0366] In some embodiments, two CMOS cameras combined into one special chip may be used. Alternatively, in some embodiments, a silicon based chip implementing a light (i.e., LED) transmitter and/or a camera or imager and/or a receiver may be used. In some embodiments, a camera implemented on a board or on a silicon chip or in combination with a silicon chip to provide RGB and depth information may be used. These embodiments may be implemented in a single independent frame such as a sensor module or system on a chip, or may be implemented into the body of a robot, using the chassis or body of the robot as a frame. The embodiments described herein may be implemented in a single chip or combined modules inside one chip. The embodiments described herein may be implemented in software and/or hardware. For example, methods and techniques for extracting 2D or 3D described may be implemented in various ways.

[0367] In some embodiments, a single laser diode with an optical lens arrangement may be used to generate two or more points. The arrangement of the lens may create a plurality of disconnected points instead of a line. The arrangement may control the distance and divergence or convergence of the points. In some embodiments, there may be a physical barrier with perforation arranged in front the lens or emitted laser line to create points. In some embodiments, mirrors may be used to generate two or more points. For example, a single LED with some optical arrangement may generate three light points, each a vertex of a triangle. In some embodiments, multiple laser diodes are used to create light points. In some embodiments, the single light source may be used to generate an arrangement of points using a mechanical filter such as that shown in FIGS. 112A-112F. FIGS. 112A and 112C illustrate a front and rear view, respectively, of the mechanical filter with openings 11200, 11201, and 11202 through which light may pass. FIGS. 112B and 112D illustrate a top plan and top perspective view of the mechanical filter with openings 11200, 11201, and 11202, and reflection absorbers 11203. FIG. 112E illustrates the constructed mechanical filter with top cover 11204. A single light source may be positioned behind the mechanical filter. A portion of the light beams from the light source may be absorbed by reflection absorbers while a portion of the light beams pass through openings 11200, 11201, and 11202. The mechanical filter thereby generates three light points from single light source. The mechanical filter is designed such that light receiving angle is 52 degrees and light reflector walls are 40 degrees with respect to a vertical. In some embodiments, lenses are used to diverge or converge light emitted by a light emitter. In some embodiments, these lenses are used as sensor windows as described above. For example, FIG. 113A illustrates a light emitter 11300 with diverging lens 11301, causing light 11302 to diverge. FIG. 113B illustrates a light emitter 11300 with converging lens 11303, causing light 11302 to converge. FIG. 113C illustrates a light receiver 11304 with converging lens 11305, causing light 11306 to converge. FIG. 113D illustrates a concave lens 11307 positioned on a sensor window of sensor 11308. FIG. 113E illustrates a convex lens 11309 positioned on a sensor window of sensor 11308.

[0368] In some embodiments, a second image sensor is provided on the baseplate. In some embodiments, the second image sensor may be positioned behind the same lens or may have its own lens. For example, FIG. 114A illustrates two cameras 11400 and 11401 each behind their own respective lens 11402 and 11403, respectively. FIGS. 114B and 114C illustrate the two cameras 11400 and 11401 behind a single lens 11404. The process of iteratively capturing images of the two or more laser light points and analyzing the distance between light points (or the surface area within light points) is repeated with images captured by the second image sensor. The two image sensors (or more image sensors in other cases) are configured to capture images simultaneously such that the distance between the baseplate and projection surface is the same in the images captured by both image sensors. In some embodiments, the image sensor determines the mean of the distances between light points (or the mean surface area within light points) in the images of each image sensor and compares the value to figures in a preconfigured table that relates distances between light points with distances between the baseplate and projection surfaces to find an estimated distance between the baseplate and the projection surface at the time of the capture of the images. A second image sensor, therefore, serves to improve the accuracy of the estimation.

[0369] Depending on the arrangement and when done advantageously, in addition to providing accuracy, the second camera can increase the field of view of the distance readings. For example, the first camera may be a blind to a range of short distances when the projected light does not fall within the field of view (FOV) of the first camera, however, the projected light may be seen with the field of view of the second camera because of difference in the position between the two cameras. Also, when implemented advantageously, the FOV of the cameras may combined to provide double the FOV or provide less than double FOV with some overlap which serves for high accuracy. The arrangement of cameras (e.g., CMOS), image sensors, laser diodes, LEDs used in a distance measurement device do not have to be in any particular arrangement so long as the arrangement of each component and geometry of the arrangement of the components are known in the software estimating the distance. Based on knowing the physical arrangement of components, the software may estimate depth of objects as described above. In some embodiments, the movement of the camera may be used to increase the FOV. For example, FIG. 115A illustrates a FOV 11500 of a single image sensor 11501 of a robot 11502. FIG. 115B illustrates the FOV 11500 of image sensor 11501 and FOV 7703 of image sensor 11504, producing increased FOV 11505. An increased FOV may similarly be achieved by movement of the camera. In some embodiments, the camera or a separate software increases the FOV.

[0370] Another technique for associating an external measurement with an image includes taking a measurement for a single point with a single point range finder such as HightSense from STMicro and using the measurement of the single point to extrapolate the measurement to the whole FOV of the image. In some embodiments, a sensor such as VL6180 or VL 53 from ST Micro is used to capture one measurement to a point in the FOV of the camera and the measurement is extrapolated based on the image processing techniques described to infer depth measurements to all obstacles in the FOV. For example, in some embodiments, two laser rangefinders, a camera, and an image processing unit are disposed on a main housing. In some embodiments, the camera and two laser rangefinders are positioned such that the laser rangefinders analyze predetermined lines of sight within the camera's image frame. In some embodiments, the laser rangefinders measure the distance to the first encountered obstacle in their respective lines of sight. Each line of sight intersects with an obstacle at an arbitrary point, which shall be referred to herein as the first and second points. In some embodiments, the camera captures an image of the area. In a next step, the image processing unit calculates the color depths at the first and second points. In a next step, the image processing unit calculates the color depth of the pixels that form a straight line between the first and second points (referred to herein as the Connecting Line) and compares the color depth of these pixels with the color depths of the first and second points. In some embodiments, if the color depth of all the pixels in the Connecting Line is consistent with (or within a preset range of) the color depths of the first and second points, the system determines that the distances of all the pixels in that region are within a threshold from the distances measured by the laser rangefinder at the first and second points. In some embodiments, when the color depth of the Connecting Line is within a preset range of the color depths of the first and second points, the system determines that the surface or obstacle being analyzed is a substantially flat surface. Further description of this method is provided in U.S. patent application Ser. Nos. 15/447,122 and 16/393,921, the entire contents of which are hereby incorporated by reference. Other depth perceiving devices that may be used to collect data from which depth may be inferred are described in U.S. patent application Ser. Nos. 15/243,783, 15/954,335, 15/954,410, 15/257,798, 15/674,310, 15/224,442, and 15/683,255, the entire contents of which are hereby incorporated by reference.

[0371] In some embodiments accuracy of depth measurement is increased when the VMP robot moves from a first location to a second location causing a second reading of a time-of-flight (TOF) camera or distance measurement device to provide a second reading which is different from the first reading at the first location. Due to the movement of the VMP robot the distances to obstacles and perimeters of the environment changes, and hence the two readings differ. Concurrently, a second image is captured with slight difference with the first image. In some embodiments, the processor compares the difference in the two images, with the differentiations between the TOF readings of both images providing the changed position of the VMP robot within the environment. For example, FIG. 116 illustrates a measured distance 11600 by a sensor of robot 11601 and resulting image 11602 in a first position and a second measured distance 11603 measured by the same sensor of robot 11601 and resulting image 11604 after moving to a second position. Image 11602 from the first position and image 11604 from the second position can be used to determine a difference between the two positions 11605. FIG. 116 may also be represented in a space-time coordinate system, wherein there is no difference in the time the images were captured, the two images taken simultaneously with the cameras being a distance apart from one another. This is shown in FIG. 117, wherein camera 11700 in a first position and camera 11701 in a second position on a robot each capture an image in respective fields of view 11702 and 11703. Because of distance 11704 between cameras 11700 and 11701, the same difference 11705 between the two images as that shown in 11605 of FIG. 116 is found. In some embodiments, this may be similar to a stereo vision apparatus. Using exteroceptive sensors, such as VL6180 or VL 53 from ST Micro, are not the only option for accomplishing the distance measuring methods described. A person of the art may identify equivalent sensors, whether they be light based, sonar based, radio based, or optical based, for example, that can provide similar effect. Any sensor, exteroceptive or proprioceptive, capable of providing the difference in position when the first image and the second image are taken, as illustrated above, may be used to accomplish the same technique.

[0372] In some embodiments, various filters may be used to smooth pixel readings. For example, a median of a combination of pixels within a threshold distance in pixel space can be used instead of using each pixel individually. Other software filters can be used to extract the line or dots or any other structured light from the image and separate it from surrounding noise and light. For example, to identify a line laser within an image, the filter may search for columns where only a single bright area is observed and for bright areas that do not exceed more than a certain number of pixels in width. A depth or breadth search can be implemented to determine which of the consecutively connected bright points in a column are likely to be the line laser and which ones are likely to be noise. In addition to search algorithms, the relationship between light points in different columns can be used to produce more accurate and noise free readings. A low or high pass filter or a combination of physical filters may be used to allow a particular wavelength inside the camera imager to reduce noise. For example, if a 920 nm laser is being used, other spectrums may be filtered out. In some embodiments, ambient light is used instead of active illumination. Alternative forms of active illumination identify a structure or pattern in a captured image and analyze the change of dimensions, shape or position and the relationship between the pattern or structure and the recorded odometry. Given the resolution of the camera and odometry or inertial information providing displacement in the real world, the change in size, shape, or position of the identified pattern or structure in the image as the robot moves can be inferred and ultimately used to infer distance to the surroundings. In other embodiments, a time of flight sensor, commonly having a narrow angular measurement range, may be used to identify the distance to objects at one or two angles. This information may be combined into the image captured, along with the features in the image, and extrapolated into a larger field of view (i.e. angular field of view of an image).

[0373] In some embodiments, depth is measured as a single measurement point without overlap. For example, the VMP robot may include a sensor, such as a TOF flightsense sensor, capable of measuring the distance to a single point. In some embodiments, the VMP robot rotates 360 degrees while the sensor measures single point distance measurements. In some embodiments, an gyroscope or other movement measurement device may be used to measure the turning angle such that a distance measurement may be associated with each degree (or any other increment of degrees, such as 0.025, 0.5, 2, or 5 degrees) of rotation. In some embodiment, a higher resolution gyroscope may be used with a high sampling rate sensor (e.g., 50 readings per second). In some embodiments, as the VMP robot rotates to complete a full turn, the robot may deviate, slipping and drifting. In such instances, the VMP robot is not actually located at the estimated location of the VMP robot, resulting in erroneous distance measurements. In some embodiments, the VMP robot may include an upward facing camera and at each measurement step may capture an image that the processor may use to adjust for the slippage by comparing the image captured to the image expected after a predetermined number of degrees of rotation. In some embodiments, the difference between the actual and the expected image may be used by the processor to correct for slippage. In some embodiments, the processor determines the amount of rotation and translation required to align the captured image with the expected image and uses the measured adjustment to adjust the VMP robot. In some embodiments, more than one TOF sensor may be used to improve depth measurements. In other cases, other configurations may be used to correct for deviation of the VMP robot. For example, the processor may extract any feature in an image and observe its displacement or the displacement of a projected laser line or arrangement of laser points. In embodiments, the orientation of the camera may vary (e.g., forward facing and angled upwards, forward facing, back facing and angled downwards, etc.).

[0374] In some embodiments, the processor compares identified features in two images captured by the same camera consecutively to estimate depth, given that motion of the camera between images is measured by, for example, a gyroscope of the VMP robot. In some embodiments, the processor compares the size of identified features, such as edges or lines between the two images. In some embodiments, the processor determines the size using pixel intensity. For example, the width or length of the number of consecutive pixels defining an edge as described above. In one instance, the processor may observe an edge in a first image but may not know if the edge is a small edge close by or a large edge further away. The speed at which the edge increases or decreases in size may be proportional to the speed of movement of the VMP robot and how far the feature is from the VMP robot. If the edge is small and close by, the edge will appear much larger in size in the consecutive image, however if the edge is large and far, the edge will not appear much larger in the consecutive image, assuming the VMP robot is moving toward the edge. The edge (or other feature) increases in size as the VMP robot moves closer and decreases in size as the VMP robot moves further away. In some embodiments, a distance sensor or camera of the VMP robot may be used to measure the distance to a feature that increases or decreases in size depending on the distance of the feature from the VMP robot. In some embodiments, the processor may estimate the distance of the feature based on the size of the feature in a captured image. Since an image shown on a CMOS or CCD camera is a lossy extraction of three-dimensions, the features detected in the camera screen form an association with each other that is proportional to the distance of those features from the VMP robot. Therefore, when one point of the image is known to be at a certain distance based on distance measurement using a one point distance sensor, other distance information of features may be extrapolated. In some embodiments, the processor compares identified features in two images captured simultaneously by two cameras positioned a known distance apart to estimate depth.

[0375] In some embodiments, the processor may detect an edge and a corner using pixel intensity as changes in intensity are usually observable at edges and corners. FIGS. 118A-118F illustrate an example of how a corner may be detected by a processor by a sliding window that moves across an image. The process begins with the processor considering area 11800 on wall 11801 and observing the changes in color intensity as shown in FIG. 118A. After observing insignificant changes in color intensity, the processor moves on and considers area 11802 with edge 11803 joining walls 11801 and 11804 and observes large changes in color intensity along edge 11803 as illustrated in FIG. 118B. In FIG. 118C the processor moves to the right to consider another area 11805 on wall 11804 and observes no changes in color intensity. In FIG. 118D it returns back to edge 11803 then moves upward to consider area 11806 as shown in FIG. 118E and observes changes in color intensity along edge 11803. Finally, in FIG. 118F the processor moves down to consider area 11807 with edges 11803 and 11808 joining walls 11801 and 11804 and floor 11809. Changes in color intensity are observed along edge 11803 and along edge 11807. Upon discovering changes in color intensity in two directions by the processor, a corner is identified. Upon discovering changes in color intensity in one direction by the processor, an edge is identified. In other instances, changes in pixel intensities may be identified by a processor of a camera. These large changes in intensity may be mathematically represented by entropy where high entropy signifies large changes in pixel intensity within a particular area. The processor may determine the entropy using

[0376] $H\left(X\right)=-\sum _{i=1}^{n}P\left(x_i\right)\log P\left(x_i\right),$
wherein X=(x₁, x₂, . . . , x_n) is a collection of possible pixel intensities, each pixel intensity represented by a digital number. P(x_i) is the probability of a pixel having pixel intensity value x_i. P(x_i) may be determined by counting the number of pixels within a specified area of interest with pixel intensity value x_i and dividing that number by the total number of pixels within the area considered. If there are no changes or very small changes in pixel intensity in an area then H(X) will be very close to a value of zero. Alternatively, the pixel values of one reading (such as those with 90 numbers) may be mapped to a continuous function and the derivative of that function considered to find areas with large changes in pixel values. With the derivative being the slope, a derivative of zero would be indicative of no change in pixel value while a derivative approaching unity would be indicative of a large change in pixel values. Other methods for edge or corner detection may be used by the processor. In some embodiments, other features can be identified to further capture the identity of the environment or objects within the environment. In some instances, features are compared with a previously created map.

[0377] In some embodiments, one or more of the depth perceiving devices described above may be used for adjusting the heading of the VMP robot. In some embodiments, one or more collimated light emitters positioned on the VMP robot emit collimated light beams in a predetermined pattern. The light pattern may include two light points, or may be more complex as described above. For the purposes of this teaching, a pattern including two light points will be used as an example. However, any pattern may be used without limitation. In some embodiments, the one or more light emitters are positioned such that light is emitted in a predetermined plane onto surfaces in front of the one or more light emitters. In some embodiments, a camera positioned on the VMP robot captures images of the light pattern as it is projected upon surfaces substantially opposite the light emitters. In some embodiments, the captured images are sent to the processor electrically coupled to the camera and the processor analyzes the images to determine whether the image of the light pattern is distorted. Distortion of the image will occur if the plane upon which the image is projected is not parallel to the plane in which the light is emitted. If the image is distorted, the plane of light emission is not parallel to the surface upon which the light is being projected. If the image is not distorted, the plane of light emission is parallel to the surface upon which the light is being projected. Depending on the results of the image analysis, the device may take any of a variety of actions to maintain or correct its heading. For example, if it is desired to maintain a heading perpendicular to walls in a workspace, the one or more light emitters and camera may be positioned parallel to the heading of the VMP robot. This way, when the camera and light emitter are perpendicular to the plane of the wall, the heading of the VMP robot will also be perpendicular to the wall. In some embodiments, the camera continuously captures images of the light pattern projected by the one or more light emitters and the processor determines if the light pattern is distorted in the captured image. If the light pattern is distorted, the processor adjusts the heading of the VMP robot by an amount proportional to the distortion. If there is no distortion in the light pattern, the heading of the VMP robot does not require adjustment.

[0378] In some embodiments, the processor detects asymmetry (or otherwise distortion) in the captured image of a particular feature (e.g., a line, a curve, a polygon, one or more points, an edge, a corner, a wall, a floor, etc.) formed by projected light points and may adjust the heading of the VMP robot by an amount proportional to the degree of asymmetry of the feature in the image. For example, the VMP robot may drive along a boustrophedon movement path, wherein the movement paths of the VMP robot are parallel to one wall and perpendicular to another. A laser of a depth perceiving device may emit six light points positioned to form a hexagon onto a wall perpendicular to a direction of movement of the VMP robot. A camera of the depth perceiving device may continuously capture images of the light points projected onto the wall. A processor of the VMP robot processes the images to determine if the projected hexagon is symmetric or asymmetric. If the image of the projected hexagon is symmetric, the heading of the VMP robot is along a movement path perpendicular to the wall on which the light points were projected, and hence does not require any adjustment. If the image of the projected hexagon is asymmetric, the heading of the VMP robot is not along the movement path perpendicular to the wall on which the light points were projected, and hence requires an adjustment proportional to the asymmetry of the projected hexagon in the captured image. In some embodiments, the processor receives a multidimensional array that includes at least one parameter describing a feature captured in an image. In some embodiments, values of the at least one parameter of the multidimensional array correspond with pixels of the image of the feature. In some embodiments, the processor determines an amount of asymmetry of the feature in the image based on at least a portion of the values of the at least one parameter. In embodiments, parameters may be qualitative (e.g., a classification) or quantitative (e.g., indicated by a numerical value). For example, a parameter may be pixel brightness given by a numerical value indicative of pixel brightness. Or in another example, a parameter may be pixel position given by the x and y coordinates of the position of the pixel in the captured image. In one example, the parameter may be feature type given by a classification of one of: line, curve, edge, corner, wall, floor, etc.

[0379] In some embodiments, the processor determines distortion by dividing the image along a division line and comparing the two portions of the image. In some embodiments, the division line is horizontal or vertical. In some embodiments, the division line is along a centerline of the image. In some embodiments, the processor compares two portions of an image by counting the number of columns of unilluminated pixels found between the division line and the first illuminated pixel (the projected light) in both left and right directions. These distances may then be compared to determine whether the points are the same distance from the division line, wherein discrepancies in distance indicate distortion and thus the need for heading adjustment. In some embodiments, the processor determines the amount of heading adjustment required based on a difference between the counted number of pixels in the left and right directions and a known ratio between an amount of heading adjustment per pixel. In some embodiments, the processor adjusts the heading such that there is no difference between the counted number of pixels in the left and right directions. In some embodiments, the processor compares two portions of the image by determining a distance between the division line and the first illuminated pixel in both left and right directions. In some embodiments, the processor determines the amount of heading adjustment required based on a difference between the distance determined in the left and right directions and a known ratio between an amount of heading adjustment per unit of distance. In some embodiments, the processor adjusts the heading such that there is no difference between the distance in the lift and right directions.

[0380] In some embodiments, the processor extracts natural features of the environment (e.g., edges and corners) from captured images and determines asymmetry of one or more of those features to determine the heading adjustment. An example of a method for extracting edges and corners is described above. In this case, the processor only requires captured images of the environment to determine heading adjustment as one or more light emitters are not required to form the feature. For example, the VMP robot may drive along a boustrophedon movement path, wherein movement paths are parallel to one wall and perpendicular to another. A camera may capture images of the wall perpendicular to the movement path of the VMP robot and a processor may extract a line separating the wall from the floor. The processor processes the image to determine if the line is symmetric or asymmetric about a vertical division line. If the extracted line in the image is symmetric, the heading of the VMP robot is along a movement path perpendicular to the wall, and hence does not require any heading adjustment. If the extracted line in the image is asymmetric, the heading of the VMP robot is not along the movement path perpendicular to the wall, and hence requires an adjustment proportional the asymmetry of the feature in the captured image. In some embodiments, the processor simply examines pixels of images captured in sequence to determine heading adjustment. Given that images captured in sequence at least partially overlap, the processor may examine the overlap of pixels between two consecutive images to determine if the pixels have moved asymmetrically from a first image captured to a second image captured consecutively. For example, the VMP robot may drive along a boustrophedon movement path, wherein movement paths are parallel to one wall and perpendicular to another. A camera may capture images of a wall perpendicular to the movement path of the VMP robot and a processor may compare the overlap of the pixels in the two images. If the overlap of pixels between a first image captured and a second image captured consecutively is asymmetric (e.g., there is more overlap on one side) then the pixels moved asymmetrically, and hence adjustment to the heading is required. If the overlap of pixels between a first image captured and a second image captured consecutively is symmetric, then the heading does not require any adjustment. Further details of a method for adjusting the heading of a robot are described in U.S. patent application Ser. Nos. 15/410,624 and 16/504,012, the entire contents of which are hereby incorporated by reference.

[0381] In some embodiments, positioning the one or more light emitters and camera on a rotatable housing allows adjustment of the heading angle that the VMP robot will maintain with relation to surfaces in the environment. The housing may be rotated such that the VMP robot maintains a heading perpendicular to surfaces, parallel to surfaces, at a 45 degree angle to surfaces, or any other angle without limitation. In some embodiments, the VMP robot may include a plurality of one or more light emitters and camera sets. In some embodiments, two sets of one or more light emitters and one camera are positioned parallel to and opposite one another to face two opposing directions. This configuration would permit the processor of the VMP robot to locate a reference surface with less movement than embodiments with only one or more light emitters and one camera.

[0382] In some embodiments, a range of certainty in the data collected may be provided for each reading. For example, in a 90-degree field of view, readings falling within the middle region of the field of view may be more accurate than those closer to the limits of the field of view. Readings taken from different distances may have different certainties or resolutions. More reflective areas may provide brighter points than less reflective areas. This may affect the level of certainty of measurements. Certain surrounding conditions, such as ambience light, may provide more confidence in the readings. In extremely bright environments, statistical and Bayesian methods may be used to filter out the noise whereas in darker environments it may be less computationally complex to identify bright points within the image.

[0383] In some embodiments, the processor of the VMP robot uses data from various sensors, such as cameras, LIDAR, and other depth sensing devices (or depth perceiving devices), to generate a spatial representation of the surroundings. In some embodiments, the mapping methods proposed herein are implemented on an ARM Cortex M7 MCU Atmel's SAM S70 processor but other similar devices or other devices that perform similar functionality may be used. In some embodiments, the VMP robot or support infrastructure (e.g., a base station or remote datacenter) may include an application specific integrated circuit (e.g., an AI co-processor ASIC) that cooperates with a physically separate or integrated central processing unit to analyze frames of video (and depth-camera readings) in the manner described herein. In some cases, the ASIC may include a relatively large number (e.g., more than 500) arithmetic logic units configured to operate concurrently on data. In some cases, the ALU's may be configured to operate on relatively low-precision data (e.g., less than or equal to 16 bits, 8 bits, or 4 bits) to afford more parallel computing units per unit area of chip substrate. In some cases, the AI co-processor ASIC may have an independent memory interface (relative to the CPU) to memory, and in some cases, independent memory from that accessed by the CPU. In some cases, the interface may be to High Bandwidth Memory (HBM), e.g., as specified by the JEDEC HBM2 specification, that includes a 3-dimensional stack of dynamic random access memory. In some cases, the memory accessed by the AI-co-processor ASIC may be packed in a multi-chip package with such a 3-dimensional stack of memory, e.g., on a shared package substrate that connects to the CPU via a system board.

[0384] In some embodiments, a camera captures spatial data while the VMP robot moves within the surroundings. In some embodiments, the VMP robot moves back and forth across the environment in straight lines, such as in a boustrophedon pattern. In some embodiments, the camera captures spatial data while the VMP robot rotates 360 degrees. In some embodiments, spatial data of the surroundings are captured continuously as the VMP robot moves around the surroundings or rotates in one or more different positions in the surroundings. In some embodiments, the camera captures objects within a first field of view. In some embodiments, the image captured is a depth image, the depth image being any image containing data which may be related to the distance from the camera to objects captured in the image (e.g., pixel brightness, intensity, and color, time for light to reflect and return back to sensor, depth vector, etc.). In one embodiment, the camera measures vectors from the camera to objects in the surroundings and the processor calculates the L2 norm of the vectors using ∥x∥_P=(Σ_i|x_i|^P)^1/P with P=2 to estimate depths to objects. In some embodiments, the camera rotates to observe a second field of view partly overlapping the first field of view and captures a depth image of objects within the second field of view (e.g., differing from the first field of view due to a difference in camera pose). In some embodiments, the processor compares the depth readings for the second field of view to those of the first field of view and identifies an area of overlap when a number of consecutive readings from the first and second fields of view are similar. The area of overlap between two consecutive fields of view correlates with the angular movement of the camera (relative to a static frame of reference of a room, for example) from one field of view to the next field of view. By ensuring the frame rate of the camera is fast enough to capture more than one frame of readings in the time it takes the camera to rotate the width of the frame, there is always overlap between the readings taken within two consecutive fields of view. The amount of overlap between frames may vary depending on the angular (and in some cases, linear) displacement of the camera, where a larger area of overlap is expected to provide data by which some of the present techniques generate a more accurate segment of the spatial representation (or otherwise map) relative to operations on data with less overlap. In some embodiments, the processor infers the angular disposition of the VMP robot from the size of the area of overlap and uses the angular disposition to adjust odometer information to overcome the inherent noise of an odometer.

[0385] Prior to measuring vectors from the camera to objects within each new field of view and estimating depths, the processor may adjust previous readings to account for the measured movement of the VMP robot as it moves from observing one field of view to the next (e.g., differing from one another due to a difference in camera pose). This adjustment accounts for the movement of the coordinate system observed by the camera o with respect to a stationary coordinate system that may or may not coincide with the first field of view of the camera. In instances wherein the camera and VMP robot move as a single unit, the observed coordinate system of the camera moves with respect to the stationary coordinate system as the VMP robot moves. In some embodiments, a movement measuring device such as an odometer, gyroscope, optical flow sensor, etc. measures the movement of the VMP robot and hence the camera (assuming the two move as a single unit) as the camera moves to observe new fields of view with corresponding new observed coordinate systems. In some embodiments, the processor stores the movement data in a movement vector and transforms all perimeter and object coordinates to correspond to, for example, the initial coordinate system observed by the camera coinciding with the stationary coordinate system. For example, in an embodiment where C is a stationary Cartesian coordinate system, C0 may be the observed coordinate system of a camera fixed to a robotic device at time t0 with state S and coinciding with stationary coordinate system C. The robotic device with attached camera displaces and the camera observes coordinate system C1 at time t1 with state S′. A movement measuring device measures the movement vector V with values (x, y, theta) and the processor uses the movement vector V to transform coordinates observed in coordinate system C1 to corresponding coordinates in coordinate system C0, coinciding with static coordinate system C. The movement vector V allows all coordinates corresponding to different coordinate systems to be transformed to a single coordinate system, such as the static coordinate system C, thereby allowing the entire perimeter to correspond to a single coordinate system. Some embodiments of the present techniques reduce a non-trivial problem to simple addition of vectors. Embodiments of this approach may be a lossy compression of the state world; but, by adjusting resolutions and creatively using mathematical estimations, acceptable results can be achieved for most home environments. With a holistic, stationary, or global coordinate system in which the camera of the robotic device observes a local coordinate system, a function that relates the local observations of the camera to the stationary or global observation can be created. A challenge can be estimating a reliable function that can provide high accuracy. For example, accounting for scenarios wherein the surface on which the robotic device operates is unlevelled whereby the odometer may measure a depth greater or smaller than the true 2D displacement. Methods for eradicating such issues have been suggested in U.S. patent application Ser. No. 15/683,255, the entire contents of which are hereby incorporated by reference, whereby a processor of the robotic device monitors declining depth measurements as a depth measurement device of the robotic device moves towards a stationary object. If the steady decline of measurements is interrupted by a predetermined number of measurements that are a predetermined percentage greater than the measurements immediately before and after the interruption, the processor discards the interrupting measurements.

[0386] In some embodiments, the processor identifies (e.g., determines) an area of overlap between two fields of view when (e.g., during evaluation a plurality of candidate overlaps) a number of consecutive (e.g., adjacent in pixel space) readings from the first and second fields of view are equal or close in value. Although the value of overlapping readings from the first and second fields of view may not be exactly the same, readings with similar values, to within a tolerance range of one another, can be identified (e.g., determined to correspond based on similarity of the values). Furthermore, identifying matching patterns in the value of readings captured within the first and second fields of view may also be used in identifying the area of overlap. For example, a sudden increase then decrease in the readings values observed in both depth images may be used to identify the area of overlap. Other patterns, such as increasing values followed by constant values or constant values followed by decreasing values or any other pattern in the values of the readings, can also be used to estimate the area of overlap. A Jacobian and Hessian matrix may be used to identify such similarities. In some embodiments, thresholding may be used in identifying the area of overlap wherein areas or objects of interest within an image may be identified using thresholding as different areas or objects have different ranges of pixel intensity. For example, an object captured in an image, the object having high range of intensity, can be separated from a background having low range of intensity by thresholding wherein all pixel intensities below a certain threshold are discarded or segmented, leaving only the pixels of interest. In some embodiments, a metric, such as the Szymkiewicz-Simpson coefficient, may be used to indicate how good of an overlap there is between the two sets of readings. Or some embodiments may determine an overlap with a convolution. Some embodiments may implement a kernel function that determines an aggregate measure of differences (e.g., a root mean square value) between some or all of a collection of adjacent readings in one image relative to a portion of the other image to which the kernel function is applied. Some embodiments may then determine the convolution of this kernel function over the other image, e.g., in some cases with a stride of greater than one pixel value. Some embodiments may then select a minimum value of the convolution as an area of identified overlap that aligns the portion of the image from which the kernel function was formed with the image to which the convolution was applied. In some embodiments, the processor determines the area of overlap based on translation and rotation of the camera between consecutive frames measured by an IMU. In some embodiments, the translation and rotation of the camera between frames is measured by two separate movement measurement devices (e.g., optical encoder and gyroscope of the VMP robot) and the movement of the VMP robot is the average of the measurements from the two separate devices. In some embodiments, the data from one movement measurement device is the movement data used and the data from the second movement measurement device is used to confirm the data of the first movement measurement device. In some embodiments, the processor uses movement of the camera between consecutive frames to validate the area of overlap identified between readings. Or, in some embodiments, comparison between the values of readings is used to validate the area of overlap determined based on measured movement of the camera between consecutive frames.

[0387] FIGS. 119A and 119B illustrate an example of identifying an area of overlap using raw pixel intensity data and the combination of data at overlapping points. In FIG. 119A, the overlapping area between overlapping image 11900 captured in a first field of view and image 11901 captured in a second field of view may be determined by comparing pixel intensity values of each captured image (or transformation thereof, such as the output of a pipeline that includes normalizing pixel intensities, applying Gaussian blur to reduce the effect of noise, detecting edges in the blurred output (such as Canny or Haar edge detection), and thresholding the output of edge detection algorithms to produce a bitmap like that shown) and identifying matching patterns in the pixel intensity values of the two images, for instance by executing the above-described operations by which some embodiments determine an overlap with a convolution. Lines 11902 represent pixels with high pixel intensity value (such as those above a certain threshold) in each image. Area 11903 of image 11900 and area 11904 of image 11901 capture the same area of the environment and, as such, the same pattern for pixel intensity values is sensed in area 11903 of image 11900 and area 11904 of image 11901. After identifying matching patterns in pixel intensity values in image 11900 and 11901, an overlapping area between both images may be determined. In FIG. 119B, the images are combined at overlapping area 11905 to form a larger image 11906 of the environment. In some cases, data corresponding to the images may be combined. For instance, depth values may be aligned based on alignment determined with the image. FIG. 119C illustrates a flowchart describing the process illustrated in FIGS. 119A and 119B wherein a processor of a robot at first stage 11907 compares pixel intensities of two images captured by a sensor of the robot, at second stage 11908 identifies matching patterns in pixel intensities of the two images, at third stage 11909 identifies overlapping pixel intensities of the two images, and at fourth stage 11910 combines the two images at overlapping points.

[0388] FIGS. 120A-120C illustrate another example of identifying an area of overlap using raw pixel intensity data and the combination of data at overlapping points. FIG. 120A illustrates a top (plan) view of an object, such as a wall, with uneven surfaces wherein, for example, surface 12000 is further away from an observer than surface 12001 or surface 12002 is further away from an observer than surface 12003. In some embodiments, at least one infrared line laser positioned at a downward angle relative to a horizontal plane coupled with at least one camera may be used to determine the depth of multiple points across the uneven surfaces from captured images of the line laser projected onto the uneven surfaces of the object. Since the line laser is positioned at a downward angle, the position of the line laser in the captured image will appear higher for closer surfaces and will appear lower for further surfaces. Similar approaches may be applied with lasers offset from a camera in the horizontal plane. The position of the laser line (or feature of a structured light pattern) in the image may be detected by finding pixels with intensity above a threshold. The position of the line laser in the captured image may be related to a distance from the surface upon which the line laser is projected. In FIG. 120B, captured images 12004 and 12005 of the laser line projected onto the object surface for two different fields of view are shown. Projected laser lines with lower position, such as laser lines 12006 and 12007 in images 12004 and 12005 respectively, correspond to object surfaces 12000 and 12002, respectively, further away from the infrared illuminator and camera. Projected laser lines with higher position, such as laser lines 12008 and 12009 in images 12004 and 12005 respectively, correspond to object surfaces 12001 and 12003, respectively, closer to the infrared illuminator and camera. Captured images 12004 and 12005 from two different fields of view may be combined into a larger image of the environment by finding an overlapping area between the two images and stitching them together at overlapping points. The overlapping area may be found by identifying similar arrangement of pixel intensities in both images, wherein pixels with high intensity may be the laser line. For example, areas of images 12004 and 12005 bound within dashed lines 12010 have similar arrangement of pixel intensities as both images captured a same portion of the object within their field of view. Therefore, images 12004 and 12005 may be combined at overlapping points to construct larger image 12011 of the environment shown in FIG. 120C. The position of the laser lines in image 12011, indicated by pixels with intensity value above a threshold intensity, may be used to infer depth of surfaces of objects from the infrared illuminator and camera (see, U.S. patent application Ser. No. 15/674,310, the entire contents of which is hereby incorporated by reference).

[0389] In some embodiments, a light point or light structure may be projected and captured in two consecutive images of the surroundings. Given the movement of the VMP robot, and the two images, the processor may determine the overlap between images. In some embodiments, movement may be measured with an optical encoder and an inertial measurement unit may be used to enhance movement measurements.

[0390] In some embodiments, the area of overlap between readings taken within the two field of views is estimated based on the measured movement of the VMP robot and is used as a method of verifying the identified area of overlap. It may also be used as the primary method of identifying the area of overlap. In this embodiment, devices such as an odometer, gyroscope, and optical flow sensor may be used to measure movement. For example, the angular displacement provided by an odometer and gyroscope and/or the mathematical convolution of the two may be used to estimate the area of overlap. In some embodiments the readings from the odometer, gyroscope and optical sensor may be combined to produce more accurate readings, e.g., with data fusion techniques and a Kalman filter. Gyroscopes and odometers provide similar readings (e.g., in vector form indicating magnitude of distance and direction). However, since each measurement device is subject to a different type of noise and different errors, combining readings from both measurement devices through a mathematical process can produce more accurate readings. In some embodiments, the VMP robot may have more than one movement measuring device in order to measure movement between each time step or fields of view observed. For example, the VMP robot may have gyroscopes and odometers that simultaneously provide redundant information. In many implementations, only one set of information is used by the processor of the VMP robot while the other is discarded. In other implementations, the processor combines the two readings by, for example, using a moving average (or some other measure of central tendency may be applied, like a median or mode) or a more complex method. Due to measurement noise, the type of measurement device used, etc. discrepancies between the measurements by a first device and a second device may exist and may not be the exact same. In such cases, the processor calculates movement of the VMP robot by combining the measurements from the first and second device, or selects measurements from one device as more accurate than the others. For example, the processor may combine measurements from the first device and the second device (or measurements from more devices, like more than three, more than five, or more than 10) using a moving average (or some other measure of central tendency may be applied, like a median or mode). The processor may also use minimum sum of errors to adjust and calculate movement of the VMP robot to compensate for the lack of precision between the measurements from the first and second device. By way of further example, the processor may use minimum mean squared error to provide a more precise estimate of the movement of the VMP robot. The processor may also use other mathematical methods to further process measured movement of the VMP robot by the first and second device, such as split and merge algorithm, incremental algorithm, Hough Transform, line regression, Random Sample Consensus, Expectation-Maximization algorithm, or curve fitting, for example, to estimate more realistic movement of the VMP robot. In another embodiment, the processor may use the k-nearest neighbors algorithm where each movement measurement is calculated as the average of its k-nearest neighbors.

[0391] In some embodiments, the processor generates a simulated representation of the VMP robot in various positions within the environment. In some embodiments, the processor generates a simulated representation of the surroundings for each hypothetical state of the VMP robot. In some embodiments, the processor compares the measurement against each simulated representation of the environment (e.g., a floor type map, a spatial map, a Wi-Fi map, etc.) corresponding with a perspective of each of the hypothetical states of the VMP robot. In some embodiments, the processor chooses the state of the VMP robot that makes the most sense as the most feasible state of the VMP robot. In some embodiments, the processor selects additional hypothetical states of the VMP robot as a backup to the most feasible state of the VMP robot.

[0392] Due to measurement noise, discrepancies between the value of readings within the area of overlap from the first field of view and the second field of view may exist and the values of the overlapping readings may not be the exact same. In such cases, new readings may be calculated, or some of the readings may be selected as more accurate than others. For example, the overlapping readings from the first field of view and the second field of view (or more fields of view where more images overlap, like more than three, more than five, or more than 10) may be combined using a moving average (or some other measure of central tendency may be applied, like a median or mode) and adopted as the new readings for the area of overlap. The minimum sum of errors may also be used to adjust and calculate new readings for the overlapping area to compensate for the lack of precision between overlapping readings perceived within the first and second fields of view. By way of further example, the minimum mean squared error may be used to provide a more precise estimate of readings within the overlapping area. Other mathematical methods may also be used to further process the readings within the area of overlap, such as split and merge algorithm, incremental algorithm, Hough Transform, line regression, Random Sample Consensus, Expectation-Maximization algorithm, or curve fitting, for example, to estimate more realistic readings given the overlapping readings perceived within the first and second fields of view. The calculated readings are used as the new readings for the overlapping area. In another embodiment, the k-nearest neighbors algorithm can be used where each new reading is calculated as the average of the values of its k-nearest neighbors. Some embodiments may implement DB-SCAN on readings and related values like pixel intensity, e.g., in a vector space that includes both depths and pixel intensities corresponding to those depths, to determine a plurality of clusters, each corresponding to readings of the same feature of an object. In some embodiments, a first set of readings is fixed and used as a reference while the second set of readings, overlapping with the first set of readings, is transformed to match the fixed reference. In some embodiments, the processor expands the area of overlap to include a number of readings immediately before and after (or spatially adjacent) readings within the identified area of overlap.

[0393] Structure of data used in inferring readings may have various forms. For example, a matrix containing pixel position, color, brightness, and intensity or a finite ordered list containing x, y position and norm of vectors measured from the camera to objects in a two-dimensional plane or a list containing time-of-flight of light signals emitted in a two-dimensional plane between camera and objects in the environment. For ease of visualization, data from which depth is inferred may be converted and reported in the format of millimeters or inches of depth; however, this is not a requirement, which is not to suggest that other described features are required. For example, pixel intensities from which depth may be inferred may be converted into meters of depth for ease of visualization, or they may be used directly given that the relation between pixel intensity and depth is known. To reduce computational expense, the extra step of converting data from which depth may be inferred into a specific format can be eliminated, which is not to suggest that any other feature here may not also be omitted in some embodiments. It is noted that each step taken in the process of transforming raw readings into a depth value in millimeters or inches is a loss and computationally expensive compression and further reduces the state space in each step when digitizing each quality. In order to reduce the loss and computational expenses, it is desired and useful to omit intermediary steps if the goal can be accomplished without them. Based on information theory principal, it is beneficial to increase content for a given number of bits. For example, reporting depth in specific formats, such as metric units, is only necessary for human visualization. In implementation, such steps can be avoided to save computational expense and loss of information. The amount of compression and the amount of information captured and processed is a trade-off, which a person of ordinary skill in the art can balance to get the desired result with the benefit of this disclosure. Depths may be perceived (e.g., measured or otherwise inferred) in any form and be reported in any format. The methods of perceiving or otherwise inferring depths and the formats of reporting depths used herein are for illustrative purposes and are not intended to limit the invention, again which is not to suggest that other descriptions are limiting.

[0394] In some embodiments, two classes of sensors are used, one acting as a predictor and the other confirming perimeter points of a work space. The predictor sensor predicts a specific coordinate as a perimeter point. The second set of sensors may either confirm or refute the prediction. For example, a predicted coordinate is proven to be false if the second set of sensors detects the VMP robot occupying the area within which the coordinate is found. If the second set of sensors detects that coordinate is within an area the VMP robot cannot access, the prediction is found true. In some embodiments, this is implemented with a low range sensor array. The second set of sensors may be, but is not limited to, a low range of IR sensors, distance sensor, tactile sensor, a bumper sensor, or other similar types of sensors.

[0395] In some embodiments, the processor identifies one or more gaps in the spatial representation of the surroundings (or otherwise map of the environment). In some embodiments, the camera is navigated to the area in which the gap exists for further exploration, capturing new images while exploring. New data is captured by the camera and combined with the existing map at overlapping points until the gap in the map no longer exists. In some embodiments, the processor identifies the gap in the map and navigates the camera to the area in which the gap exists. In some embodiments, the perimeters and objects in the map may be stored in memory of and used by the VMP robot to perform tasks within discovered areas of the map. As the VMP robot performs a task, it marks the areas covered within the map (e.g., in memory) to avoid repeat coverage. While the VMP robot performs work in discovered areas, it continues to take images and merge the data them with the existing map to close any gaps in the perimeters that may exist and, in the process, may discover previously undiscovered areas. In some embodiments, the discovered area is split into sections that are covered by the VMP robot in succession starting from the section closest to the VMP robot and ending at the sections furthest away. Any other order may be acceptable depending on the situation. After covering discovered areas within the surroundings, the VMP robot identifies any remaining gaps in the perimeters that may have not been closed while performing work in the discovered area. These gaps may be due to, for example, an opening in the wall, such as in the case of a door or an opening between separated areas, blind spots unseen by the sensor, or a lack of data resulting from a sensor with inadequate detection range.

[0396] In some embodiments, the VMP robot moves towards the undiscovered area within which a first gap is located while continuously taking images of the undiscovered area and merging the data from the images taken within overlapping successive field of views together at the area of overlap between successive field of views. Some embodiments may interrogate a map in memory to detect undiscovered areas. An area may be designated as undiscovered if no data, less than a threshold amount of data, or data of less than a threshold confidence, exists in a particular region. Thus, undiscovered areas may be distinguished from open areas by measurements being taken in an area by the VMP robot. The VMP robot may continue to explore undiscovered areas within which the gap is located by taking images and combining them with previously taken images until the gap no longer exists (e.g., measurements with greater than a threshold spatial resolution are obtained). During exploration of undiscovered areas within which gaps are located, the VMP robot may perform work (e.g., clean) in new areas discovered. If it does perform work, areas covered may be marked in order to avoid repeat coverage. In some embodiments, the processor of the VMP robot may split the newly discovered areas into sections and the VMP robot may successively cover each section one at a time, finishing cleaning on one area before moving on to the next area. The VMP robot continues to explore unrecognized areas in the map within which gaps are identified until no gaps exist and the perimeter is a complete closed loop.

[0397] In some embodiments, after exploring undiscovered areas within which identified gaps are located and covering all discovered areas within the map, the VMP robot moves along the perimeters of the environment while using sensory devices, such as tactile sensors (like bump sensors) or short-range IR sensors, facing towards the perimeters of the map to verify that no additional gaps exist. For example, the VMP robot may use the tactile sensor to observe physical contact between the VMP robot and the perimeters as it follows along the perimeter of the map to ensure no additional gaps exist. In some embodiments, an additional gap may be observed while following along the perimeters, in which case the VMP robot may proceed to explore (e.g., position its sensors such that it can image) the undiscovered areas while mapping newly discovered areas as described above. In some embodiments, the VMP robot returns back to its home base after moving along the perimeters to check that no additional gaps exist. In some embodiments, the actions of covering internal areas within the map and moving along the perimeters can alternate. For example, the internal areas of one room can be covered and movement around the perimeters completed before moving on to the internal area and perimeters of a second room. In other embodiments, the location of the perimeters sensed may be compared to the location of the perimeters in the map to check for accuracy. For example, using a tactile sensor, the location at which physical contact between the VMP robot and perimeters are observed can be compared to the corresponding location within the map to check if there are coinciding perimeters. This method may also be used to determine ground truth of the location of the perimeters in comparison to the perceived location of the perimeters. In some embodiments, ground truth may be used to adjust measurements or the perimeters. The VMP robot may move along the perimeters and compare its sensed position to that of the perimeters at any time during or after the process of plotting the perimeters of the map.

[0398] In some embodiments, where the gap in the perimeters is due to an opening in the wall, when for example, there is a doorway or an opening between two separate areas, exploration of the undiscovered areas within which the gap is identified can lead to the discovery of a room, a hallway or any other separate area. During exploration of undiscovered areas, the camera continues to measure distances to objects within its field of view such that newly discovered areas, such as a room, hallway, or any other area, are added to the plotted map by combining new distance measurements with the perimeters at overlapping points. In some embodiments, identified gaps that are found to be, for example, an opening in the wall are used in separating areas into smaller subareas. For example, the opening in the wall between two rooms may be used to segment the area into two subareas, where each room is a single subarea. This could be expanded to five rooms, for example, where each room separated from rooms adjacent to it by an opening in the wall may be segmented into five subareas using the openings in the walls as dividers. In some embodiments, the processor of the VMP robot provides a unique tag to each subarea and uses the unique tag to order the subareas for coverage by the VMP robot, choose different work functions for different subareas, add restrictions to subareas, set cleaning schedules for different subareas, and the like.

[0399] In some embodiments, wherein the VMP robot detects a second room beyond an opening in the wall detected within a first room being covered, the opening in the wall between the two rooms is identified as a doorway. In such embodiments, to identify the doorway connecting the two rooms, the VMP robot may cover the internal space within the first room, but remain distanced from the boundaries detected. The VMP robot may then cover (e.g., with a serpentine coverage path or other paths) the internal space within the first room again but this time reach closer to the boundaries detected. The VMP robot may record covered areas. For example, the VMP robot may mark areas covered within a map or record coordinates corresponding to areas covered. The distance between the outer edge of the recorded first internal space covered and areas of the recorded second internal space covered are determined, where the distance measured is perpendicular to the outer edge of the first internal space. In some embodiments, recorded areas of the second internal space covered that are below a threshold distance may be discarded and any remaining recorded areas of the second internal space may be referred to as an outside space. The centroids of the recorded outside spaces and the recorded first internal space covered may be determined and path lines between centroid of the first internal space and centroids of outside spaces may be created. The segments of the path lines passing through the internal space and outside spaces are discarded leaving only path lines connecting the outer edges of the internal space to the outer edges of the outside spaces. The one or more processors of the VMP robot may then mark openings in the wall as a doorway using an iterative process where a theoretical doorway line perpendicular to each path line is fitted to perimeter data. At each iteration, a doorway line moves further along a corresponding path line, beginning closer to the internal space, until the doorway line aligns with the perimeter data, at which point the doorway line is identified as a doorway. In some embodiments, the line of sight of the VMP robot is limited and only a small area beyond the opening in the wall is discovered. In such cases, the VMP robot moves closer to the opening in the wall and scans to discover enough area and hence collect more data beyond the opening in the wall before deciding to initiate the steps described for identifying a doorway. In some embodiments, walls are geometrically modeled as a line and an opening in the wall is detected by a deviation in depth data from a line fitted to the depth data, where depth data beyond a deviation threshold is considered to be an opening in the wall.

[0400] In some embodiments, a depth sensor of the VMP robot outputs range and light intensity for every reading taken such that the number of readings taken at a single time point depends on the angular resolution of the depth sensor and the size of the field of view. For example, a reading may be taken every 0.5° or every 2° for a 100° field of view resulting in 200 or 50 readings at a single time point, respectively. If more than one set of readings is taken for a particular field of view, the processor averages the data for each angular resolution. Since depth sensors have a minimum and maximum detectable range, invalid and undefined readings may result from out of range measurements (i.e. those too far or too close to the depth sensor). To eliminate these undefined values, the processor assigns them a large number and filters them out from the measurements of the environment. In embodiments, the processor also filters out outliers due to noise, corrupt data, etc. For example, FIG. 121 illustrates readings taken by a depth sensor for a particular field of view. Data points 12100 with value of 6 meters, the maximum range of the depth sensor, are considered invalid data points resulting from out of range data and are filtered out by the processor. Remaining data points are fitted to a line model and any deviation from the line model are identified as an opening in the wall by the processor. Data points 12101, for example, are identified by the processor as a deviation from a line model and are considered an opening in the wall. In embodiments, the range and light intensity recorded by the depth sensor for each reading is used by the processor to calculate an error associated with deviation of the range data from a line model. The processor of the VMP robot relates the light intensity and range of a point captured by the depth sensor using

[0401] $I\left(n\right)=\frac{a}{{r\left(n\right)}^4},$
wherein I(n) is the intensity of point n, r(n) is the distance of the particular point on an object and a=E(I(n)r(n)⁴) is a constant that is determined by the processor using a Gaussian assumption.

[0402] FIG. 122 illustrates VMP robot 12200 with depth sensor 12201 with field of view 12202 of 90°, the center of the field of view located at 0° and spanning to +45° and −45° on either side. Distance 12203 to object 12204 taken with field of view 12202 measured at angle 0° is the minimum distance d_min of all readings taken within field of view 12202, while distance 12205 measured at angles +/−45° are the maximum distance d_max. Given d_min, the processor calculates the distance

[0403] $r\left(n\right)=\frac{d_{\min }}{\sin \left(-\theta \left(n\right)\right)}$
corresponding to a point n on an object at any angular resolution θ(n). This is shown in FIG. 122 wherein angle 12206 of point 12207 on object 12204 corresponds to θ(n) of point n in the equation above. The horizon

[0404] $\alpha =a\sin \frac{d_{\min }}{d_{\max }}$
of the depth sensor is also computed by the processor given d_min and d_max. This is shown in FIG. 122 as angle 12208. The processor uses a combined error

[0405] $e=\sum {\left(I\left(n\right){r\left(n\right)}^4-a\right)}^2+{\left(r\left(n\right)-\left(\frac{d_{\min }}{\sin \left(-\theta \left(n\right)\right)}\right)\right)}^2$
of the range and light intensity output by the depth sensor to identify deviation from the line model and hence detect an opening in the wall. The error e is minimal for walls and significantly higher for an opening in the wall, as the data will significantly deviate from the line model. A threshold is used by the processor to determine whether the data points considered indicate an opening in the wall when, for example, the error exceeds some threshold value.

[0406] In some embodiments, the processor uses an adaptive threshold wherein the values below the threshold may be considered to be a wall. An adaptive threshold across the data is determined by the processor of the VMP robot by averaging a number of local measurements. For example, threshold value x_i is determined by the processor as the average of the local data measurements spanning from x_i+1 to x_i+L, wherein L determines the number of local data measurements considered in calculating threshold value x_i. In some embodiments, order statistics is also used by the processor to determine adaptive threshold values. FIG. 123 illustrates range data 12300 and fixed threshold 12301 as well as adaptive threshold 12302. Adaptive threshold 12302 is adjusted based on range data in the local region of interest. In certain cases, wherein a fixed threshold value is used, certain regions may be incorrectly identified as a wall, such as region 12303.

[0407] In some embodiments, the processor does not consider openings with width below a specified threshold as an opening in the wall, such as openings with a width too small to be considered a door or too small for the VMP robot to fit through. The processor of the VMP robot estimates the width of the opening in the wall by identifying angles φ with a valid range value and with intensity greater than or equal to

[0408] $\frac{a}{d_{\max }}.$
The difference between the smallest and largest angle among all

[0409] $\phi =\left\{\theta \left(n\right)\bigvee \left(\left\{r\left(n\right)\ne \infty \right\}\right)\bigwedge \left(I\left(n\right)\ge {\left(\frac{a}{d_{\max }}\right)}^4\right)\right\}$
angles provide an estimate of the width of the opening. The width of an opening in the wall may also be determined by the processor by identifying the angle at which the measured range noticeably increases and the angle at which the measured range noticeably decreases and taking the difference between the two angles.

[0410] Similar to the line model method described above, in some embodiments a wall or opening in the wall is detected by the processor using recursive line fitting of the data. The processor of the VMP robot compares the error (y−(ax+b))² of data points n₁ to n₂ to a threshold T₁ and summates the number of errors below the threshold. The processor then computes the difference between the number of points considered (n₂−n₁) and the number of data points with errors below threshold T₁. If the difference is below a threshold T₂, i.e.,

[0411] $\left(\left(n_2-n_1\right)-\sum _{n_1}^{n_2}{\left(y-\left(\mathrm{ax}+b\right)\right)}^2<T_1\right)<T_2,$
then the processor assigns the data points to be a wall otherwise assigns the data points to be an opening in the wall.

[0412] In another embodiment, the processor uses entropy to predict an opening in the wall, as an opening in the wall results in disordered measurement data and hence larger entropy value. When the entropy surpasses a certain threshold, it can be assumed to be an opening in the wall. Entropy of the measurement data is determined by the processor using

[0413] $H\left(X\right)=-\sum _{i=1}^{n}P\left(x_i\right)\log P\left(x_i\right)$
wherein X=(x₁, x₂, . . . , x_n) is a collection of possible data measurements, such as depth measurements. P(x_i) is the probability of a depth measurement having value x_i. P(x_i) may be determined by, for example, counting the number of measurements within a specified area of interest with value x_i and dividing that number by the total number of measurements within the area considered. In some embodiments, the processor compares entropy of measurement data to entropy of measurement data of a wall. For example, the entropy may be computed for the probability density function (PDF) of the data to predict if there is an opening in the wall in the region of interest. In the case of a wall, the PDF may show localization of readings around wall coordinates, thereby increasing certainty and reducing entropy. For example, FIG. 124 illustrates PDF of x-coordinate reading, wherein localization is shown as the peak in probability density 12400, indicating high certainty of a wall and hence lower entropy. In some embodiments, a region of interest is identified as an opening in the wall by the processor when the entropy surpasses a specified threshold. During measurement, the depth sensor may encounter three types of barriers, namely, an object, a wall, or the maximum depth senor range. In most cases, objects are concentrated around the wall of the environment and, hence, the probability of finding an object near a wall is higher. Each depth reading has a value with some probability. In any given row of the 2D x-y data the processor of the VMP robot takes the average of the y-component as the PDF estimate for the x-component,

[0414] $P\left(x\right)=\int P\left(x,y\right)\mathrm{dy}\cong \int \frac{1}{N}\mathrm{dy}=\frac{1}{N}\sum y.$

[0415] In some embodiments, a probabilistic method is applied by pre-training the processor of the VMP robot with a classifier to provide a priori prediction. In embodiments, a supervised machine learning algorithm is used by the processor to identify features of openings and walls. A training set of, for example, depth data is used by the processor to teach the classifier common features or patterns in the data corresponding with openings and walls such that the processor can identify walls and openings in walls with some probability distribution. In this way, a priori prediction from a classifier combined with real-time measurement is used together to provide a more accurate prediction of a wall or opening in the wall. In some embodiments, Bayes Theorem is used by the processor to provide probability of an opening in the wall given that the VMP robot is located near an opening in the wall,

[0416] $P\left(A|B\right)=\frac{P\left(B|A\right)P\left(A\right)}{P\left(B\right)}·P\left(A|B\right)$
is the probability of an opening in the wall given that the VMP robot is located close to an opening in the wall, P(A) is the probability of an opening in the wall, P(B) is the probability of the VMP robot being located close to an opening in the wall, and P(B|A) is the probability of the VMP robot being located close to an opening in the wall given that an opening in the wall is detected.

[0417] The different methods described for detecting an opening in the wall above may be combined in some embodiments and used independently in others. Examples of methods for detecting a doorway are described in, for example, U.S. patent application Ser. Nos. 15/615,284 and 16/163,541, the entire contents of which are hereby incorporated by reference. In some cases, the steps described for identifying a doorway are executed after identifying an opening in the wall. Different types of depth measurement devices may be used that are capable of measuring depth or data from which depth may be inferred, such as LIDAR, LADAR, depth sensor, TOF sensor, stereo vision and other distance or depth measuring devices. In some embodiments, more than one measurement device may be used simultaneously. In some embodiments, the processor of the VMP robot may mark the location of doorways within a map of the environment. For example, FIG. 125 illustrates VMP robot 12500 within workspace 12501 with two subareas 12502 and room 12503 divided by wall 12504 and connected by door 12505. Depth sensor 12506 measures the range to objects within the environment, such as wall 12504. The range data is fitted to a line model by the processor of the VMP robot. The data which fit the line model are assigned as a wall by the processor while range data that deviates from the line model by some error threshold are assigned as a door. As VMP robot 12500 rotates in direction 12507, part of the ranges measured within the field of view of depth sensor 12506 correspond with wall 12504 as well as door 12505. The ranges corresponding with door 12505 will be significantly greater than those measured for adjacent wall 12504 and, hence, will deviate from the line model. This sudden deviation can be identified by any of the methods described above for detecting an opening in a wall. In some embodiments, the VMP robot may be configured to avoid crossing the identified doorway for a predetermined amount of time or until the VMP robot has encountered the doorway a predetermined number of times. In some embodiments, the VMP robot may be configured to drive through the identified doorway into a second subarea for cleaning before driving through the doorway in the opposite direction. In embodiments, the VMP robot may be configured to execute any number of actions upon identification of a doorway and different actions may be executed for different doorways. In some embodiments, the processor uses doorways to segment the environment into subareas. In some embodiments, the processor represents subareas using a stack structure, for example, for backtracking purposes wherein the path of the VMP robot back to its starting position can be found using the stack structure.

[0418] To find an optimal location to move to, such that the VMP robot is able to best discover the opening in the wall and beyond, lines normal to a frontier of the area to be discovered are determined. From the normal lines a series of ray tracing may then be used to find a location suitable for the VMP robot to move to by first defining an area through which the rays pass. One or more processors of the VMP robot may mark the defined area in a map, for example, or record coordinates corresponding to the defined area. The defined area may also be recorded in any other form. To ensure the VMP robot is not too close to the frontier, in some embodiments, the defined area may be trimmed such that areas close to the frontier are eliminated. The centroid of the defined area is then used as the location the VMP robot moves to. In other embodiments, other locations within the defined area may be used. In some cases, the identified gap is simply a depression and the steps described for identifying a doorway are not required.

[0419] Due to noise in measurement and movement, in some embodiments, there are accumulating inaccuracies in the perimeters discovered as the VMP robot moves from one room to another. As the number of rooms increases the inaccuracies may accumulate further. For example, due to movement noise, a VMP robot intending to move directly forward into a second room from a first adjacent room may in reality have moved to a location further away. This movement noise results in the perimeters of the second room misaligning with the perimeters of the first room. In some embodiments, a room graph is created where each room is defined separately in order to avoid or minimize such issues. The room graph may be a mathematical graph that has nodes representing the rooms and vectors determining how the rooms are connected to one another. In some embodiments, each room has its own properties associated with it such as a centroid, a first set of perimeter points corresponding to an initial scan of the room, a completed set of perimeter points where all perimeters and doors are captured, a last set of perimeter points corresponding to the last scan of the room, a set of doors with an associated field of view, doors labelled with the room to which they lead to, a unique number and/or label to identify the room and flags signifying visitations to the room. For example, the doorways in each perimeter may be identified to have a path to adjacent rooms such that the VMP robot may return back to the first room after covering multiple rooms. For example, a wall and doorway shared between two rooms are found in both the boundaries of the first room and the second room. The doorway in the perimeter of the first room is identified to have a path to the second room and the doorway in the perimeter of the second room is identified to have a path to the first room.

[0420] In some embodiments, the processor of the VMP robot applies a room planner to keep track of the paths executed through the rooms and the rooms visited and to suggest one or more paths for the VMP robot to follow. For example, if there are two doors in a room, the room planner can suggest which door to go through. In embodiments, the room planner can also suggest alternative paths if a particular room is not accessible when, for example, a previously identified door is closed or blocked. In embodiments, the room planner has different modes, such as exploration mode wherein the VMP robot is configured to explore undiscovered areas or return to start mode wherein the VMP robot is configured to return to its initial starting point in the working environment. In embodiments, the room planner chooses the current perimeter view of each room and switches between different perimeter views of a room as each room can have multiple different sets of perimeters. For example, when the VMP robot first enters a room, the room planner of the VMP robot determines that the partial perimeter initially observed by a depth sensor of the VMP robot best matches with data of a perimeter view of the previous room and initially uses that perimeter as the view of the VMP robot. However, as the depth sensor of the VMP robot observes more areas within the room, the room planner finds that a perimeter view of the current room better matches the observations and switches the view of the VMP robot. In embodiments, the room planner chooses which perimeter view of a room to use based on a specific task of the VMP robot. For example, if the VMP robot is exiting a second room to enter a first room, the room planner finds it beneficial to load only the inside perimeter of the first room rather than all sets of perimeters of the first room. In embodiments, the room planner can apply MDP in a similar manner as described above for determining, for example, the optimal order in which different rooms are covered or the optimal coverage path. For example, the first time (or first few times) the room planner advises the next room to be visited on a pseudo random basis and monitors the performance. Then every time it experiments with the order of rooms, it monitors how the performance changes using a cost function that is penalized with movement of the VMP robot odometer. The goal is for the room planner to minimize the cost function over time and, once the algorithm converges, it is likely to provide the best possible order for visiting the rooms. In embodiments, the cost function can include other or additional penalizing factors, such as repeat coverage or distance travelled from on subarea to another. For example, a VMP robot can travel through rooms A, B, C, and D in the stated order to reach room D, meanwhile room D may have a direct connection to room A. Over time the system may converge such that the VMP robot is configured to travel directly to room D from room A rather than travelling through rooms B and C first to get to room D. In some embodiments, to avoid falling into a local minima, optimization is controlled by the processor of the VMP robot to achieve a balance between exploration and exploitation. The processor of the VMP robot controls the amount of time spent on exploration versus exploitation. In embodiments, the room planner is a component of the processor of the VMP robot or is an external component coupled to the processor of the VMP robot or may be included in an application of a mobile device and may be implemented in software, hardware, or both.

[0421] The VMP robot may use the map to autonomously navigate the environment during operation, e.g., a cleaning or other work session. In some embodiments, the plotted (e.g., mapped, e.g., in vector or bitmap form) perimeters are stored in memory for future use. Storage of the map may be in temporary memory such that a map is only available during an operational session or in more permanent forms of memory such that the map is available at the next session or startup. In some embodiments, the map is further processed to identify rooms and other segments. In some embodiments, a new map is constructed at each use. In some embodiments, the map may be externally stored on another device such as the docking station or other base station of a VMP robot or in the cloud (e.g., in memory of a server at a remote data center) or other remote storage device.

[0422] The door detection techniques described above apply to some embodiments of the depicted approach. For example, FIG. 126A illustrates an embodiment consistent with the above techniques wherein camera 12600 mounted on VMP robot 12601 is measuring distances 12602 within first field of view (i.e. field of view) 12604. Distance measurements 12602 taken by camera 12600 measure the distance from camera 12600 to object 12605, which in this case is a wall. FIG. 126B illustrates 2D perimeter segment 12606 resulting from plotted distance measurements 12602 taken within first field of view 12604. Dashed lines 12607 demonstrates that resulting 2D perimeter segment 12604 corresponding to distance measurements 12602 taken within field of view 12604. In some embodiments, 3D distance measurements are taken and plotted to construct 3D perimeter segments of the map.

[0423] FIG. 127A illustrates camera 12600 mounted on VMP robot 12601 measuring distances 12700 within second field of view 12701 partly overlapping distance measurements 12602 within first field of view 12604. After distance measurements 12602 within first field of view 12604 are taken, VMP robot 12601 with mounted camera 12600 moves to observe overlapping second field of view 12701 and take distance measurements 12700. As VMP robot 12601 moves to observe second field of view 12701, the values of distance measurements 12602 taken within first field of view 12604 are adjusted to account for the movement of VMP robot 12601. Distance measurements 12702 represent the area of overlap between distance measurements 12602 taken within field of view 12604 and distance measurements 12700 taken within field of view 12701.

[0424] FIG. 127B illustrates 2D perimeter segments 12606 and 12703 resulting from distance measurements 12602 and 12700, respectively. While shown aligned, the processor may receive the data in a format in which each segment is in a distinct coordinate system, e.g., each in pixel coordinates of a different image. Segments 12606 and 12703 are bounded by dashed lines 12607 and 12704, respectively. 2D perimeter segment 12705 constructed from the combination of 2D perimeter segments 12606 and 12703 and bounded by the outermost dashed lines of 12607 and 12704 is also illustrated. Distance measurements 12700 captured within second field of view 12701 are compared to distance measurements 12602 captured within first field of view 12604 to identify the area of overlap bounded by the innermost dashed lines of 12704 and 12607. The processor of the VMP robot may compare measurements and determine the area of overlap using different methods. In some embodiments, an area of overlap may be identified in response to detecting an iteration of comparison in which a number of consecutive distance values measured from the first field of view and second field of view are equal or close in value. Although the values of overlapping distance measurements from the first and second fields of view may not be exactly the same, distances with similar values, to within a tolerance range of one another, can be identified (e.g., determined to correspond based on similarity of the values). For example, the processor may compute a root mean square (RMS) delta of values between consecutive fields of view at a spatial offset. The spatial offset is incremented until a first derivative of the RMS delta crosses zero or a global minimum is found. Furthermore, identifying matching patterns in the value of distances measured within the first and second fields of view can also be used in identifying the area of overlap. For example, a sudden increase then decrease in the distance values observed in both sets of measurements may be used to identify the area of overlap. Examples include applying an edge detection algorithm (like Haar or Canny) to the fields of view and aligning edges in the resulting transformed outputs. Other patterns, such as increasing values followed by constant values or constant values followed by decreasing values or any other pattern in the values of the measured distances, can also be used to estimate the area of overlap. A Jacobian and Hessian matrix can be used to identify such similarities. In some embodiments, thresholding may be used in identifying the area of overlap wherein areas or objects of interest within an image may be identified using thresholding as different areas or objects have different ranges of pixel intensity. For example, an object captured in an image, the object having high range of intensity, can be separated from a background having low range of intensity by thresholding wherein all pixel intensities below a certain threshold are discarded or segmented, leaving only the pixels of interest. In some embodiments, a metric can be used to indicate how good of an overlap there is between the two sets of perceived depths, such as the Szymkiewicz-Simpson coefficient. Or some embodiments may determine an overlap with a convolution. Some embodiments may implement a kernel function that determines an aggregate measure of differences (e.g., a RMS value) between some or all of a collection of adjacent distance readings in one image relative to a portion of the other image to which the kernel function is applied. Some embodiments may then determine the convolution of this kernel function over the other image, e.g., in some cases, with a stride of greater than one pixel value. Some embodiments may then select a minimum value of the convolution as an area of identified overlap that aligns the portion of the image from which the kernel function was formed with the image to which the convolution was applied. Areas of overlap may also be identified in response to other detected comparisons. For example, the one or more processors of the VMP robot may use pixel patterns and/or features and/or patterns of columns, rows, and/or curves with high brightness (to which arcs or lines may be fitted) to determine overlapping points of similarities between two different images).

[0425] In some embodiments, the measured movement of VMP robot 12601 over one time step, as it moves from observing first field of view 12604 to observing second field of view 12701, is used to estimate the area of overlap between distance measurements 12602 and 12700 and is used to verify the identified area of overlap. In some embodiments, the area of overlap identified using the methods described above is verified if the identified overlap is within a threshold angular distance of the overlap estimated using measured movement. In some embodiments, the processor uses the measured movement to choose a starting point for the comparison between measurements from the first field of view and measurements from the second field of view. For example, the processor uses the measured movement to choose a starting point for the comparison between measurements from the first field of view and measurements from the second field of view. The processor iterates using a method such as that described above to determine the area of overlap. The processor verifies the area of overlap if it is within a threshold angular distance of the overlap estimated using measured movement.

[0426] In some embodiments, measured movement of VMP robot 12601 may be used as the primary method of determining the area of overlap. Movement measuring devices such as odometer, gyroscope, structure from motion, and optical flow sensor may be used to measure movement of VMP robot 12601. In some embodiments, the processor stores the movement data in a movement vector and transforms all distance measurements to correspond to, for example, an initial coordinate system of a first field of view observed by the camera coinciding with a stationary coordinate system. For example, in an embodiment where C is a stationary Cartesian coordinate system, C0 may be the observed coordinate system of a first field of view of a camera fixed to a VMP robot at time t0 with state S and coinciding with stationary coordinate system C. The VMP robot with attached camera displaces and the camera observes coordinate system C1 of a second field of view of the camera at time t1 with state S′. A movement measuring device measures the movement vector V with values (x, y, theta) as the VMP robot moves from observing a first field of view to a second field of view. The processor uses the movement vector V to transform distances observed in coordinate system C1 of the second field of view to corresponding distances in coordinate system C0 of the first field of view, coinciding with static coordinate system C. The movement vector V allows all measurements corresponding to different coordinate systems of different fields of view observed to be transformed to a single coordinate system, such as the static coordinate system C, thereby allowing all perimeters to correspond to a single coordinate system. Further details of this method are provided in U.S. patent application Ser. No. 16/163,508, the entirety of which is hereby incorporated by reference.

[0427] 2D perimeter segment 12606 from plotted distance measurements taken within first field of view 12604 and 2D perimeter segment 12703 from plotted distance measurements taken within second field of view 12701 may be combined at the area of overlap to construct larger 2D perimeter segment 12705. When the values of overlapping distance measurements from field of view 12604 and 12701 within the area of overlap are slightly different, an analytical method, such as a data or sensor fusion algorithm, averaging, minimum sum of errors, or any other suitable method is used to calculate a single distance value for each pair of overlapping distance measurements that can result in a more accurate ground truth as compared to the distance measurements initially taken. In some embodiments, the processor of the VMP robot may select an analytical method, such data or sensor fusion algorithms, minimum mean square error or sum of squared residuals minimization or any other method to merge multiple data sets together. Further, the one or more processors of the VMP robot may additionally use other mathematical processing to improve accuracy of the data in order to achieve better alignment between successive sets of overlapping distance measurements.

[0428] In some embodiments, this method is repeated such that distance measurements captured within successively overlapping field of views may be combined to construct the perimeters of the entire map.

[0429] FIG. 128 illustrates data produced by an embodiment where complete closed loop 2D perimeter 12800 is constructed from plotted distance measurements taken within successively overlapping field of views. 2D perimeter 12800 can, for example, be used by VMP robot 12601 with mounted camera 12600 to autonomously navigate within the map during operation. Some embodiments may determine a coverage path based on the area bounded by perimeter 12800.

[0430] In some instances, the perimeters of the map are incomplete where gaps are observed within the perimeters due to lack of distance measurements. The lack of distance measurements may be due to, for example, an opening in the wall, blind spots unseen by the measuring device or a lack of data resulting from a measuring device with inadequate detection range. FIG. 129A illustrates VMP robot 12900 with mounted camera 12901 rotating in direction 12903 while taking distance measurements within field of view 12904. In this example, VMP robot 12900 is attempting to plot a 2D perimeter from distance measurements taken within successively overlapping field of views by rotating camera 12901 by 360 degrees. At this first-time point, camera 12901 is able to detect wall 12902 within field of view 12904 of camera 12901. FIG. 129B illustrates VMP robot 12900 with mounted camera 901 taking distance measurements within field of view 12906 at a second-time point. Although the position of VMP robot 12900 is approximately at the center of map 12907, camera 12901 cannot detect wall 12902 in area 12905 within field of view 12906 due to the shape of map 12907.

[0431] FIG. 129C illustrates resulting incomplete perimeters 12908 of map 12907. Perimeters 12908 are incomplete as distances were not measured for a section of map 12907 due to a blind spot unseen by camera 12901, resulting in undiscovered area 12909 within which a gap exists. Despite the gap, incomplete perimeters 12908 are used by VMP robot 12900 to perform work in discovered area 12910 of map 12907 as described above. As VMP robot 12900 covers area 12910 it marks (e.g., in memory, on a map) covered areas within perimeters 12908 to avoid repeat coverage. While performing work in discovered area 12910, VMP robot 12900 continues to take distance measurements and merge them with existing perimeters 12908 to close any gaps which may exist. In some embodiments, discovered area 12910 is segmented into sections and VMP robot 12900 performs work in each section successively, beginning with sections closest to VMP robot 12900 and ending with the sections furthest away from VMP robot 12900. For illustrative purposes, assume after completing coverage in discovered area 12910, undiscovered area 12909 within which a gap located still exists. In some embodiments, VMP robot 12900 then travels towards undiscovered area 12909 while taking distance measurements.

[0432] For example, some embodiments may form a double connected edge list (DCEL) and then select edges of the perimeters having only one vertex in the list. Embodiments may then navigate the VMP robot to an opposing vertex of the selected edges that is not part of the DCEL. Or some embodiments may cause the VMP robot to traverse a path in an arc centered on such a point while facing the point.

[0433] VMP robot 12900, in some embodiments, explores undiscovered area 12909 wherein a gap is identified by taking distance measurements and combining them with previously measured overlapping distance measurements until the gap in undiscovered area 12909 no longer exists. In some embodiments, VMP robot 12900 performs work in the new areas it discovers as it explores undiscovered area 12909 wherein the gap is located. If VMP robot 12900 does perform work in newly discovered areas during exploration, in some embodiments, newly discovered areas are split into sections and VMP robot 12900 covers them one at a time.

[0434] In some embodiments, VMP robot 12900 explores undiscovered area 12909 wherein the gap is located in perimeters 12908 before performing work in discovered area 12910. In any case, as VMP robot 12900 moves, it marks areas covered within perimeters 12908 to avoid repeat coverage. In some embodiments, VMP robot 12900 uses marked areas within the perimeters of the map to decide whether to cover marked areas again based on the path of the VMP robot, the user settings, and/or its coverage algorithm. FIG. 129D illustrates complete closed loop perimeters 12911 of map 12907 after exploration of undiscovered area 12909 is complete. In some embodiments, after exploring undiscovered areas within which identified gaps are located and covering all discovered areas within the perimeters, the VMP robot moves along the perimeters while using sensory devices to verify that no additional gaps exist.

[0435] FIG. 129E illustrates an embodiment wherein VMP robot 12900 discovers an extension to discovered area 12910 upon exploring the undiscovered area within which a gap was located (FIG. 129D). The VMP robot may determine, based on sensed data, that the initially observed gap in the perimeters was due to opening in the wall 12911 separating two areas using the techniques discussed above. Opening in the wall 12911 can be used to segment total area 12910 outlined by dashed lines in FIG. 129E using the techniques discussed above, into smaller subareas 12912 and 12913 each separately outlined by dashed lines in FIG. 129F. Subareas 12912 and 12913 may be treated independently, wherein the VMP robot can be programmed to operate and execute tasks within a particular subarea. For example, the VMP robot may be programmed to execute a wall-follow coverage algorithm in subarea 12912 and rectangular-spiral coverage algorithm in subarea 12913, or to only clean subarea 12913, or to clean subarea 12912 and 12913 on particular days and times. In some embodiments, unique tags, such as a number or any label, can be assigned to each subarea. In some embodiments, the user assigns unique tags to each subarea, and embodiments receive this input and associate the unique tag (such as a human-readable name of a room, like “kitchen”) with the area in memory. Some embodiments may receive instructions that map tasks to areas by these unique tags, e.g., a user may input an instruction to the VMP robot in the form of “vacuum kitchen,” and the VMP robot may respond by accessing the appropriate map in memory that is associated with this label to effectuate the command. In some embodiments, the VMP robot assigns unique tags to each subarea. For example, 12912 and 12913 can be considered unique tags used to identify two separate subareas. The unique tags can be used to set and control the operation and execution of tasks within each subarea and to set the order of coverage of each subarea. For example, the VMP robot can be programmed to cover subarea 12912 first and subarea 12913 last. In some embodiments, the order of coverage of the subareas is such that repeat coverage within the total area is minimized. In another embodiment, the order of coverage of the subareas is such that coverage time of the total area is minimized. The order of subareas can be changed depending on the task or desired outcome. The example provided only illustrates two subareas for simplicity but can be expanded to include multiple subareas, spaces, or environments, etc.

[0436] In some embodiments, an opening in the wall separating two rooms is identified as a doorway. For example, consider FIG. 130A, where first room 13000, opening in the wall 13001, and an area beyond 13001 are discovered. In some embodiments, to identify opening in the wall 13001 as a doorway, a VMP robot may cover first internal space 13002 within first room 13000 but remain distanced from the boundaries detected as illustrated in FIG. 130B. The VMP robot may then cover second internal space 13003 within the first room 13000, but this time reaches closer to the boundaries detected. The processor of the VMP robot may record covered areas. For example, the processor may mark areas covered within a map or record coordinates corresponding to areas covered. Other methods of recording areas covered may also be used. Distances 13004 between the outer edge of recorded first internal space 13002 covered and recorded second internal space 13003 covered, beyond first internal space 13002, are determined. Recorded areas from second internal space 13003 that are below threshold distance 13005 are discarded and remaining recorded area 13003, as shown in FIG. 130C, is referred to as an outside space. Centroids 13006 and 13007 of first internal space 13002 and outside space 13005, respectively, are determined and path line 13008 between centroids 13006 and 13007 is created. Path line 13008 passing through first internal space 13002 and outside space 13005 may be trimmed leaving only path line 13008 connecting the outer edge of first internal space 13002 to outer edge of outside space 13005 as shown in FIG. 130D. The processor of the VMP robot then marks opening in the wall 13001 as a doorway using an iterative process where theoretical doorway line 13009 perpendicular to path line 13008 connecting the outer edge of first internal space 13002 and the outer edge of outside space 13005 is fit to perimeter 13010. At each iteration, doorway line 13009 moves further along path line 13008, beginning closer to first internal space 13002, until doorway line 13009 aligns with perimeter 13010, at which point the one or more processors identify doorway line 13009 as a doorway and designated as such in memory.

[0437] In some embodiments, as in the case shown in FIG. 130E, the line of sight of the VMP robot is limited and only a small area beyond opening in the wall 13001 in room 13000 is discovered. In such cases, the VMP robot moves closer to opening in the wall 13001 and scans to discover enough area beyond opening in the wall 13001 before initiating the steps described above for identifying a doorway. To find the optimal location to move to, such that the VMP robot is able to best discover opening in the wall 13001 and beyond, lines 13011 normal to frontier 13012 of the area to be discovered are determined as illustrated in FIG. 130F. From normal lines 13011, a series of rays 13013 are used to find a location suitable for the VMP robot to move to by first defining area 13014 through which rays 13013 pass. The defined area may, for example, be marked in a map or coordinates corresponding to the defined area may be recorded in memory. To ensure (or increase the likelihood that) the VMP robot is not too close to frontier 13012, defined area 13014 is trimmed such that areas close to frontier 13012 are eliminated, as shown in FIG. 130G. Centroid 13015 of defined area 13014 may then be used as the location the VMP robot moves to in order to discover opening in wall 13001 and beyond. In other embodiments, other locations within defined area 13014 may also be used. In some cases, the opening in the wall is simply a depression and the steps described for identifying a doorway are not required as described herein.

[0438] FIG. 131 depicts an example of a VMP robot 13100 with processor 13101, memory 13102, a first set of sensors 13103, second set of sensors 13104, network communication 13105, movement driver 13106, timer 13107, and more or more cleaning tools 13108. The first and second set of sensors 13103 and 13104 may include depth measuring devices, movement measuring devices, and the like. In some embodiments, the VMP robot may include the features of a VMP robot described herein. The shape of the illustrated features is not meant to imply that the VMP robot has a round shape or that any feature has any particular shape. In some embodiments, program code stored in the memory 13102 and executed by the processor 13101 may effectuate the operations described herein. Some embodiments additionally include user device 13109 having a touchscreen 13110 with a software application coupled to the VMP robot 13100.

[0439] FIG. 132 illustrates a flowchart describing embodiments of a path planning method of a VMP robot 13200, 13201, 13202, 13203, 13204, 13205 and 13206 corresponding with steps performed in some embodiments.

[0440] In some embodiments, a precision coefficient is calculated for each distance measurement. The value of the precision coefficient of a distance measurement is influenced by the value of the precision coefficient of distance measurements within its vicinity, the number of close-by distance measurements with high precision coefficient, the similarity between and the number of overlapping distance measurements recorded within separate field of view. For example, if the values of overlapping distance measurements from two successive field of views within the overlapping area are exactly the same, the value of the precision coefficient may have more positive change than if the values of overlapping distance measurements need a slight mathematical adjustment to be aligned together. In some embodiments, a tolerance range within which distance measurements are expected to fall within is established and the position of a distance measurement with respect to the tolerance range influences the value of its precision coefficient. In other embodiments, the value of the precision coefficient of distance measurements is influenced by the size of the overlapping area within which the distance measurement lies. For example, if the area of overlap between two successive field of view is large, the value of precision coefficient of distance measurements within the area of overlap may be more positively influenced and may be a better estimate of the ground truth than if they lied within a smaller area of overlap.

[0441] In some embodiments, more than two sets of distance measurements may overlap. The combination of increased number of overlapping sets of distance measurements results in distance measurements with more accurate ground truth. In other embodiments, each distance measurement overlaps with at least one other distance measurement taken from another field of view (i.e. field of view).

[0442] While the examples and illustrations provided apply the some of the present techniques to the construction of a 2D perimeters using 2D distance measurements, the 2D perimeters may be constructed using 3D distance measurements as well. Furthermore, embodiments may construct 3D perimeters of the map using 3D distance measurements. The 3D perimeters of the map may be plotted using at least one camera, such as a distance measuring camera, capable of taking 3D distance measurements. 3D distance measurements taken within overlapping field of views may be combined at identified areas of overlap where overlapping distance measurements are used as the attachment points. In some embodiments, 2D perimeters can be extracted from the plotted 3D perimeters.

[0443] In some embodiments, the map is constructed in a coordinate system, where measured distances are expressed in coordinates and marked within the coordinate system. The coordinate system can be a Cartesian, polar, or homogenous coordinate system or any other coordinate system. In some embodiments, distances expressed in one type of coordinate system may be translated to another type of coordinate system. For example, distances expressed as Cartesian coordinates may be translated to polar, homogenous or any other type of coordinates or distances expressed as polar coordinates may be translated to Cartesian, homogenous or any other type of coordinates. Translated coordinates may be marked within a corresponding coordinate system to plot the perimeters.

[0444] The resulting plot of the perimeters may be encoded in various forms. For instance, some embodiments may construct a point cloud of three dimensional points by transforming vectors into a vector space with a shared origin, e.g., based on the above-described vectors, in some cases displacement vectors may be used and refined based on measured depths. Some embodiments may represent maps with a set of polygons that model detected surfaces, e.g., by calculating a convex hull over measured vectors within a threshold area, like a tiling polygon. Polygons are expected to afford faster interrogation of maps during navigation and consume less memory than point clouds at the expense of greater computational load when plotting.

[0445] In embodiments, constructing the map of the environment from 3D point clouds can be advantageous as certain features that may be indistinguishable in a 2D point cloud may be identified in a 3D point cloud. For example, with 2D point clouds, depth readings to objects are only captured at a particular height, therefore, if there is an obstacle in the surface of an environment, such as a bump, the processor of the VMP robot may be unaware. However, with a 3D point cloud, the obstacle may be observed as sensors of the VMP robot may take readings in all three directions. For example, FIG. 133A illustrates top and side view of robotic vacuum 13300 and readings 13301 taken in the x- and y-direction by sensor 13302. Since readings 13301 are only taken in the x- and y-direction, slight slope 13303 may be identified as an obstacle, such as a wall, resulting in robotic vacuum 13300 avoiding area 13304 while it is actually accessible by robotic vacuum 13300 for cleaning. FIG. 133B illustrates top and side views of robotic vacuum 13300 and readings 13305 taken in the x-, y-, and z-direction by sensor 13302. Since readings 13305 are taken in the x-, y-, and z-direction, slight slope 13303 may be identified as a climbable obstacle resulting in robotic vacuum 13300 cleaning area 13304. In embodiments, the control system of the VMP robot may be trained using deep learning to distinguish between features such as, climbable bump, unclimbable bump, wall, and furniture within the working environment. For example, FIG. 134 illustrates VMP robot 13400 and readings 13401 taken in the x-, y-, and z-direction by sensor 13402. The processor of VMP robot 13400 may distinguish protrusion 13403 and slope 13404 within the 3D point cloud and based on their features may classify them as climbable or unclimbable obstacles. For example, protrusion 13403 may be classified as climbable while slope 13404 may be classified as unclimbable. In some embodiments, a protrusion and/or slope may be distinguished as climbable or unclimbable based on the reward historically generated for past protrusions and/or slopes with similar features to those being considered, wherein the magnitude of the reward may be based on the level of completion of the climbing path.

[0446] In some embodiments, more than one camera may be used to improve accuracy of the map. For example, a plurality of distance measuring cameras (e.g., carried by the VMP robot) may be used simultaneously (or concurrently) wherein distance measurements from each camera are used to more accurately plot the perimeters of the map. The use of a plurality of distance measuring cameras is expected to allow for the collection of distance measurements from different perspectives and angles, for example. Where more than one distance measuring camera is used, triangulation or others suitable methods may be used for further data refinement and accuracy. In some embodiments, a 360-degree LIDAR is used to create perimeters of the map. It should be emphasized, though, that embodiments are not limited to techniques that construct maps in this way, as the present techniques may also be used for plane finding in augmented reality, barrier detection in virtual reality applications, outdoor mapping with autonomous drones, and other similar applications, which is not to suggest that any other description is limiting. In some embodiments, other mapping methods may be used in generating a spatial representation of the surroundings, such as the mapping methods described in U.S. patent application Ser. Nos. 16/048,179, 16/048,185, 16/163,541, 16/163,562, and 16/163,508, the entire contents of which are hereby incorporated by reference.

[0447] In some embodiments, the processor of the VMP robot may generate multiple maps of the environment over multiple working sessions. The maps may be stored in a memory of the VMP robot and may be combined with previously generated maps to keep the map of the environment up to date. In some embodiments, a predetermined map of the environment may be generated and stored in an internal memory of the VMP robot. In some embodiments, the VMP robot may generate a map of the environment during operation in the environment. In some embodiments, the processor may update the internal map of the environment with observations collected during each successive work session. Continuous updates to the map of the environment may help establish the most efficient path of the VMP robot. In some embodiments, the processor of the VMP robot generates a local map and a global map. In some embodiments, the processor integrates the local map into the global map. In some embodiments, the processor only observes a portion of the global map that is local relative to the location of the VMP robot. In some embodiments, one or more local maps are superimposed on a global map. In some instances, local maps are combined to create a global map. In some instances. The processor generates a local map and determines its location based on locating the local map within the global map by detecting similar features between the two maps.

[0448] The VMP robot may, for example, use the map to autonomously navigate the environment during operation, e.g., accessing the map to determine that a candidate route is blocked by an obstacle denoted in the map, to select a route with a route-finding algorithm from a current point to a target point, or the like. To avoid false detection of an obstacle, in some embodiments, each location within the map is assigned an obstacle probability indicating the probability of an obstacle existing in each respective location. The obstacle probability assigned to a particular location increases each time an obstacle is observed in the particular location, and the processor qualifies an obstacle as existing in a particular location only when the obstacle probability is greater than a predetermined threshold. For example, all locations in a map are initially set to an obstacle probability of 0.25 (i.e., 25% chance that an obstacle exists in each location). When an obstacle is observed in a particular location, the obstacle probability increases to 0.325, and if observed a second time in the same particular location the obstacle probability increases to 0.3925, and so on. When the obstacle probability assigned to a particular location is greater than 0.325, the processor qualifies an obstacle as existing in the particular location. In some embodiments, the map is stored in memory for future use. Storage of the map may be in temporary memory such that a stored map is only available during an operational session or in more permanent forms of memory such that the map is available at the next session or startup. In some embodiments, the map is further processed to identify rooms and other segments. Examples of methods for dividing an environment into zones are described in U.S. patent application Ser. Nos. 14/817,952, 16/198,393, and 15/619,449, the entire contents of which are hereby incorporated by reference. In some embodiments, a new map is constructed at each use, or an extant map is updated based on newly acquired data.

[0449] In some embodiments, the memory of the VMP robot may include an internal database of obstacles likely to be encountered within the environment. In some embodiments, an obstacle encountered in the environment may be identified using various sensors to capture features of the obstacle and the processor may determine the type of obstacle based on the internal database. The processor may note the increased likelihood of that type of obstacle being located in the region of the environment in which it was encountered. In some embodiments, the processor may mark the location in the map. For example, images sensors of the VMP robot continuously capture images, and if the VMP robot encounters a wire on the floor, the processor analyzes images of the wire to extract features of the obstacle and compares them with features of obstacles within the internal database to determine that it is a wire. The processor may mark the region in which the wire was encountered within an internal map as a region with increased likelihood of containing a wire. In some embodiments, the processor may further determine if an obstacle may be overcome by the VMP robot. For example, the processor may determine if the wire is an obstacle that may be overcome by the VMP robot by, for example, driving over the wire. If so, the VMP robot may attempt to drive over the obstacle. If, however, the VMP robot encounters a large obstacle, such as a chair or table, the processor may determine that it cannot overcome the obstacle and may attempt to maneuver around the obstacle and continue along its path. In some embodiments, regions wherein obstacles are consistently encountered may be classified by the processor as a high obstacle density area and may be marked in the map of the environment. In some embodiments, the processor may attempt to alter its path to avoid high obstacle density areas. In some embodiments, the processor may alert a user when an unanticipated obstacle blocking the path of the VMP robot is encountered, particularly when the VMP robot may not overcome the obstacle by maneuvering around or driving over the obstacle. The VMP robot may alert the user by generating a noise, sending a message to an application of a communication device paired with the VMP robot or any other device paired with the VMP robot, displaying a message on a screen of the VMP robot, illuminating lights, and the like.

[0450] In some embodiments, the processor has access to multiple coordinate systems with different resolutions and is able to switch from one resolution to another depending on the accuracy required. For example, the processor of the VMP robot may use a high-resolution coordinate system when finding the perimeter of the place and a low-resolution coordinate system when covering the internal area of the place or moving from one location to another. As a further example, if the processor wants the VMP robot to remain distanced from obstacles the processor may use a low-resolution coordinate system. In some embodiments, the processor evaluates the performance of the VMP robot in executing actions using different coordinate system resolutions. In embodiments, the processor uses a Markov Decision Process (MDP) consisting of a sequence of states and actions followed by rewards. Actions are taken to transition from one state to another and, after transitioning to each new state, the processor assigns a reward. For a sequence of states and actions, the processor calculates a net reward as the sum of rewards received for the sequence of states and actions, with future rewards discounted. The expected net reward for the execution of a sequence of states and actions is given by a state-action value function. The processor is configured to find the optimal state-action value function by identifying the sequence of states and actions, including coordinate system resolution to use in executing the actions, with highest net reward. Since multiple actions can be taken from each state, the goal of the processor is to also find an optimal policy that indicates the action, including coordinate system resolution to use in executing the action, from each state with the highest reward value. For example, if the VMP robot is observed to bump into an obstacle while executing an action using a low-resolution coordinate system, the processor calculates a lower reward than when the VMP robot completes the same action free of any collision using a high-resolution coordinate system, assuming collisions with obstacles reduces the reward achieved. If this is repeated over time, the processor eventually derives a policy to execute that particular action using a high-resolution coordinate system as it achieves higher reward. In embodiments, as the VMP robot executes more actions using high- and low-resolution coordinate systems over time, data is gathered on the reward assigned to each state and action, the action including the coordinate system resolution used in executing the action. In embodiments, the processor compares the reward received for executing an action from one state to another using a high-resolution coordinate system and executing the same action using a low-resolution coordinate system. Over time the processor determines a policy that maximizes the net reward. In embodiments, the sequence of states and actions corresponds to the states visited and actions taken (including the resolution of the coordinate system used in completing each action) while, for example, executing a work session from start to finish. Over time, as more states are visited and different actions from each state are evaluated, the system will converge to find the most optimal action (including the resolution of the coordinate system used in completing each action) to take from each state thereby forming an optimal policy. Further, as different sequences of states and actions are evaluated over time, the system will converge to the most optimal sequence of states and actions. For example, consider the states visited and actions taken from each state while cleaning a room using a high and low-resolution coordinate system. If the VMP robot has multiple encounters with obstacles and coverage time is increased while executing actions from different states during the cleaning session the processor calculates a lower net reward (assuming collisions and cleaning time are factors in determining the reward value) than when completing the cleaning session collision free using a high-resolution coordinate system. If this is continuously observed over time, the processor derives a policy to use a high-resolution coordinate system for the particular actions taken while cleaning the room. In this example, only two levels of coordinate system resolution are considered for illustrative purposes, however, the processor can consider a greater number of different resolution levels.

[0451] In some embodiments, the VMP robot is configured with a first exteroceptive sensor (e.g., depth sensor) and a second proprioceptive sensor (e.g., gyroscope, such as in a three or six axis inertial measurement unit (IMU)), the data of which the processor uses simultaneously and interchangeably for mapping and localization of the VMP robot. In some embodiments, data from one sensor is used in a primary method for mapping and localization while data from the other sensor is used in a secondary method for mapping and localization. The processor uses the secondary method for mapping and localization when, for example, the sensor used in the primary method for mapping and localization malfunctions, becomes unusable or is functionally affected by the environment. For example, in direct sunlight a first exteroceptive sensor, such as a depth camera, may not provide the reliable readings required for a primary method for mapping and localization. In such instances, the processor uses a secondary method for mapping and localization using data from a second proprioceptive sensor, such as a gyroscope, to localize the VMP robot and mark the area covered by the VMP robot such that repeat coverage is avoided. The transition between the primary and secondary method may be seamless (e.g., occurring within less than 10 seconds, less than 1 second, or less than 500 milliseconds, and resulting in less than 1 cm, 10 cm, or 50 cm of error in position over 10 seconds of travel) and may be controlled with a finite state machine. In some embodiments, the processor uses the secondary method to verify output of the primary method. In some embodiments, one sensor is active (e.g., depth sensor emitting light to the environment and measuring reflected light) and the other sensor is passive (e.g., gyroscope measuring movement). For example, data from a digital camera (i.e., passive sensor) is used in a primary method for mapping and localization and data from a wheel encoder (i.e., active sensor) is used in a secondary method for mapping and localization.

[0452] In some embodiments, IMU measurements in a multi-channel stream indicative of acceleration along three or six axes may be integrated over time to infer a change in pose of the VMP robot, e.g., with a Kalman filter. In some cases, the change in pose may be expressed as a movement vector in the frame of reference of the room through which the VMP robot moves. Some embodiments may localize the VMP robot or map the room based on this movement vector (and contact sensors in some cases) even if the camera is inoperative or degraded. In some cases, IMU measurements may be combined with image-based (or other exteroceptive) mapping data in a map or localization determination. Or in some cases, data from one active sensor may be used at a time for localization or mapping, and the other sensor may remain passive, e.g., sensing data, but that data may not be used for localization or mapping while the other sensor is active. Some embodiments may maintain a buffer of sensor data from the passive sensor (e.g., including measurements over a preceding duration, like one second or ten seconds), and upon failover from the active sensor to the passive sensor, which may then become active, some embodiments may access the buffer to infer a current position or map features based on both currently sensed data and buffered data. In some embodiments, the buffered data may be calibrated to the location or mapped features from the formerly active sensor, e.g., with the above-described sensor fusion techniques.

[0453] In some embodiments, the VMP robot is configured with high resolution sensors, the data of which the processor uses to locally enhance observed perimeters. For example, a VMP robot may be configured with a long-range, low-resolution depth camera and a short-range (e.g., 50 cm), high-resolution TOF sensor. The processor may use the TOF sensor to locally discover perimeters. In embodiments, the processor combines locally discovered perimeters with globally discovered perimeters. In some embodiments, the VMP robot visits perimeters discovered after a first mapping session to observe the perimeters using higher resolution sensors. In some embodiments, discovery of perimeters is executed offline and saved in a memory of the VMP robot or online wherein the perimeter map is saved to, for example, the cloud. In some embodiments, the perimeter map is updated online in an incremental manner.

[0454] In some embodiments, the processor uses captured sensor data of objects, such as walls or furniture, within the surrounding environment to update the location of the VMP robot within the perimeter map such that the processor is aware of the position of the VMP robot relative to perimeters and objects within the environment as it operates. As the VMP robot moves within the environment and sensors capture data, the processor tracks the position of the VMP robot relative to observed objects within the environment by associating newly captured data of objects with previously captured data of objects. Prior to associating newly captured sensor data of objects with previously captured sensor data of objects, the processor updates the estimated position of previously captured objects relative to the VMP robot based on the most recent state of the objects and the motion model of the VMP robot. In some embodiments, the processor associates new sensor data with previously captured sensor data of different objects within the environment by defining acceptance gates around current estimated positions of previously captured objects. The newly captured sensor data that falls within an acceptance gate of an object and is closest to the updated estimated position of the object is associated with the corresponding previously captured sensor data of the object. However, over time, as the VMP robot moves around the environment and observes more objects and collects more sensor data, determining to which previously captured object newly captured sensor data is associated to becomes increasingly challenging. In such instances, the processor uses a probabilistic data association filter (PDAF) to associate newly captured sensor data with previously captured sensor data of observed objects within the environment. The PDAF considers all sensor data falling within the acceptance gate, wherein instead of updating the position of an object based on a single best matched observation, the PDAF updates based on all observations falling within the gating window, weighted by their likelihoods. In some embodiments, the PDAF accounts for the statistical distribution of sensor data errors and clutter and assumes that only one of the candidate observations within the gating window is a match, and the rest are false alarms. In other embodiments, the processor uses other methods for tracking the location of the VMP robot within the perimeter map of the place during mapping and/or operation. For example, in one embodiment the processor uses scan matching techniques wherein the optimization algorithms, such as Gauss-Newton or Levenberg-Marquardt, are used to find the best match between scans by minimizing the error between the data of the scans.

[0455] In some embodiments, cliffs are marked as obstacles in the map. In some embodiments, cliffs are detected using edge sensors as described above. In some embodiments, the cliffs marked as obstacles in the map prevent the VMP robot from visiting the cliff area more than one time. Without the cliffs marked as obstacles in the map, the VMP robot may attempt to visit the cliff area multiple times. Although the cliffs are detected by the edge detection sensors and prevent the VMP robot from moving past the cliff, the processor may not learn that the cliff area is off limits and may try to visit the cliff area multiple times. By adding cliffs to the map as obstacles, the VMP robot may avoid returning to cliff area again during the same work session and in future work sessions if the map is saved. FIGS. 135A-135C illustrate how a movement path of the VMP robot may evolve over time. FIG. 135A illustrates the movement path 13500 of the VMP robot 13501 during a first time visiting cliff area 13502 of staircase 13503. After detecting cliff area 13502 for the first time, the processor marks the cliff area 13502 as perimeter, similar to perimeter of the wall 13504 adjacent to cliff area 13502. FIG. 135B illustrates the movement path 13505 of the VMP robot 13501 after visiting the cliff area 13502 a second time, wherein the processor treats the cliff area 13502 as a perimeter and follows along the perimeter without trying to cross over the perimeter as illustrated in FIG. 135A FIG. 135C illustrates a coverage path 13506 of the VMP robot 13501 after marking cliff area 13502 as an obstacle in the map. In future coverage of the environment, the VMP robot does not attempt to explore the cliff area with edge detection sensors by crossing over. The processor treats the cliff area as a perimeter of the environment and directs the VMP robot to move along a smooth line parallel to the cliff line as it if was a wall, as illustrated in the examples shown in FIGS. 135B and 135C.

[0456] In some instances where linear algebra is used, Basic Linear Algebra Subprograms (BLAS) may be implemented to carry out operations such as vector addition, vector norms, scalar multiplication, matrix multiplication, matric transpose, matrix-vector multiplication, linear combinations, dot products, cross products, and the like.

[0457] The techniques described herein, e.g., such as mapping and depth perceiving techniques, may be implemented in software, in hardware, in a system on a chip, a module, a combination with other hardware on a PCB, in a single silicon chip, a combination of software and one or more silicon chips, a combination of software and a multi-purpose chip, or a specific application chip with built in mapping capabilities. In some embodiments, the implementations may include built-in circuitry for easier and faster processing and GPUs and TPUs capabilities. In some embodiments, a mapping chip or a processing chip with a mapping processing unit may be used.

[0458] In some embodiments, the processor localizes itself during mapping or during operation. In some embodiments, methods of localization are inherently independent from mapping and path planning but may be used in tandem with any mapping or path planning method or may be used independently to localize the VMP robot irrespective of the path or map of the environment. In some embodiments, the processor uses quantum SLAM.

[0459] In some embodiments, the processor localizes the VMP robot within an environment represented by a phase space or Hilbert space. In some embodiments, the space includes all possible states of the VMP robot within the space. In some embodiments, a probability distribution may be used by the processor of the VMP robot to approximate the likelihood of the state of the VMP robot being within a specific region of the space. In some embodiments, the processor of the VMP robot determines a phase space probability distribution over all possible states of the VMP robot within the phase space using a statistical ensemble including a large collection of virtual, independent copies of the VMP robot in various states of the phase space. In some embodiments, the phase space consists of all possible values of position and momentum variables. In some embodiments, the processor represents the statistical ensemble by a phase space probability density function ρ(p,q,t), q and p denoting position and velocity vectors. In some embodiments, the processor uses the phase space probability density function ρ(p,q,t) to determine the probability ρ(p,q,t)dq dp that the VMP robot at time t will be found in the infinitesimal phase space volume dq dp. In some embodiments, the phase space probability density function ρ(p,q,t) has the properties ρ(p,q,t)≥0 and ∫ρ(p,q,t)d(p,q)=1, ∀t≥0, and the probability of the position q lying within a position interval

[0460] $a,b\mathrm{is}P\left[a\le q\le b\right]={\int }_a^b\int \rho \left(p,q,t\right)\mathrm{dpdq}.$
Similarly, the probability of the velocity p lying within a velocity interval c, d is

[0461] $P\left[c\le q\le d\right]={\int }_c^d\int \rho \left(p,q,t\right)\mathrm{dqdp}.$
In some embodiments, the processor determines values by integration over the phase space. For example, the processor determines the expectation value of the position q by q=∫q ρ(p,q,t)d(p,q).

[0462] In some embodiments, the processor evolves each state within the ensemble over time t according to an equation of motion. In some embodiments, the processor models the motion of the VMP robot using a Hamiltonian dynamical system with generalized coordinates q, p wherein dynamical properties are modeled by a Hamiltonian function H. In some embodiments, the function represents the total energy of the system. In some embodiments, the processor represents the time evolution of a single point in the phase space using Hamilton's equations

[0463] $\frac{\mathrm{dp}}{\mathrm{dt}}=-\frac{\partial H}{\partial q},\frac{\mathrm{dq}}{\mathrm{dt}}=\frac{\partial H}{\partial p}.$
In some embodiments, the processor evolves the entire statistical ensemble of phase space density function ρ(p,q,t) under a Hamiltonian H using the Liouville equation

[0464] $\frac{\partial \rho }{\partial t}=-\left\{\rho ,H\right\},$
wherein {⋅,⋅} denotes the Poisson bracket and H is the Hamiltonian of the system. For two functions ƒ, g on the phase space, the Poisson bracket is given by

[0465] $\left\{f,g\right\}=\sum _{i=1}^N\left(\frac{\partial f}{\partial q_i}\frac{\partial g}{\partial p_i}-\frac{\partial f}{\partial p_i}\frac{\partial g}{\partial q_i}\right).$
In this approach, the processor evolves each possible state in the phase space over time instead of keeping the phase space density constant over time, which is particularly advantageous if sensor readings are sparse in time.

[0466] In some embodiments, the processor evolves the phase space probability density function ρ(p,q,t) over time using the Fokker-Plank equation which describes the time evolution of a probability density function of a particle under drag and random forces. In comparison to the behavior of the VMP robot modeled by both the Hamiltonian and Liouville equations, which are purely deterministic, the Fokker-Planck equation includes stochastic behaviour. Given a stochastic process with dX_t=μ(X_t,t)dt+σ(X_t,t)dW_t, wherein X_t and μ(X_t,t) are M-dimensional vectors, σ(X_t, t) is a M×P matrix, and W_t is a P-dimensional standard Wiener process, the probability density ρ(x,t) for X_t satisfies the Fokker-Planck equation

[0467] $\frac{\partial \rho \left(x,t\right)}{\partial t}=-\sum _{i=1}^M\frac{\partial }{\partial x_i}\left[{\mu }_i\left(x,t\right)\rho \left(x,t\right)\right]+\sum _{i=1}^M\sum _{j=1}^M\frac{{\partial }^2}{\partial x_i\partial x_j}\left[D_{ij}\left(x,t\right)\rho \left(x,t\right)\right]$
with drift vector μ=(μ₁, . . . , μ_M) and diffusion tensor

[0468] $D=\frac{1}{2}\sigma {\sigma }^T.$
In some embodiments, the processor adds stochastic forces to the motion of the VMP robot governed by the Hamiltonian H and the motion of the VMP robot is then given by the stochastic differential equation

[0469] $d{X}_t=\left(\begin{array}{c}dq\\ dp\end{array}\right)=\left(\begin{array}{c}+\frac{\partial H}{\partial p}\\ -\frac{\partial H}{\partial q}\end{array}\right)\mathrm{dt}=\left(\begin{array}{c}{0}_N\\ {\sigma }_N\left(p,q,t\right)\end{array}\right)d{W}_t,$
wherein σ_N is a N×N matrix and dW_t is a N-dimensional Wiener process. This leads to the Fokker-Plank equation

[0470] $\frac{\partial \rho }{\partial t}=-\left\{\rho ,H\right\}+{\nabla }_p·\left(D{\nabla }_p\rho \right),\mathrm{wherein}{\nabla }_p$
denotes the gradient with respect to position p, ∇⋅ denotes divergence, and

[0471] $D=\frac{1}{2}{\sigma }_N{\sigma }_N^T$
is the diffusion tensor.

[0472] In other embodiments, the processor incorporates stochastic behaviour by modeling the dynamics of the VMP robot using Langevin dynamics, which models friction forces and perturbation to the system, instead of Hamiltonian dynamics. The Langevian equations are given by M{umlaut over (q)}=∇_qU(q)−γp+√{square root over (2γk_BTM)}R(t), wherein (−γp) are friction forces, R(t) are random forces with zero-mean and delta-correlated stationary Gaussian process, T is the temperature, k_B is Boltzmann's constant, γ is a damping constant, and M is a diagonal mass matrix. In some embodiments, the Langevin equation is reformulated as a Fokker-Planck equation

[0473] $\frac{\partial \rho }{\partial t}=-\left\{\rho ,H\right\}+{\nabla }_p·\left(\gamma p\rho \right)+k_{B}T{\nabla }_p·\left(\gamma M{\nabla }_p\rho \right)$
that the processor uses to evolve the phase space probability density function over time. In some embodiments, the second order term ∇_p·(γM∇_pρ) is a model of classical Brownian motion, modeling a diffusion process. In some embodiments, partial differential equations for evolving the probability density function over time may be solved by the processor of the VMP robot using, for example, finite difference and/or finite element methods.

[0474] FIG. 136A illustrates an example of an initial phase space probability density of a VMP robot, a Gaussian in (q,p) space. FIG. 136B illustrates an example of the time evolution of the phase space probability density after four time units when evolved using the Liouville equation incorporating Hamiltonian dynamics,

[0475] $\frac{\partial \rho }{\partial t}=-\left\{\rho ,H\right\}$
with Hamiltonian

[0476] $H=\frac{1}{2}{p}^2.$
FIG. 136C illustrates an example of the time evolution of the phase space probability density after four time units when evolved using the Fokker-Planck equation incorporating Hamiltonian dynamics,

[0477] $\frac{\partial \rho }{\partial t}=-\left\{\rho ,H\right\}+{\nabla }_p·\left(D{\nabla }_p\rho \right)\mathrm{with}D=0.1.$
FIG. 136D illustrates an example of the time evolution of the phase space probability density after four time units when evolved using the Fokker-Planck equation incorporating Langevin dynamics,

[0478] $\frac{\partial \rho }{\partial t}=-\left\{\rho ,H\right\}+{\nabla }_p·\left(\gamma p\rho \right)+k_{B}T{\nabla }_p·\left(\gamma M{\nabla }_p\rho \right)$
with γ=0.5, T=0.2, and k_B=1. FIG. 136B illustrates that the Liouville equation incorporating Hamiltonian dynamics conserves momentum over time, as the initial density in FIG. 136A was only distorted in the q-axis (position). In comparison, FIGS. 136C and 136D illustrate diffusion along the p-axis (velocity) as well, as both evolution equations account for stochastic forces. With the Fokker-Planck equation incorporating Hamiltonian dynamics the density spread more equally (FIG. 136C) as compared to the Fokker-Planck equation incorporating Langevin dynamics where the density remained more confined (FIG. 136D) due to the additional friction forces.

[0479] In some embodiments, the processor of the VMP robot may update the phase space probability distribution when the processor receives readings (or measurements or observations). Any type of reading that may be represented as a probability distribution that describes the likelihood of the state of the VMP robot being in a particular region of the phase space may be used. Readings may include measurements or observations acquired by sensors of the VMP robot or external devices such as a Wi-Fi™ camera. Each reading may provide partial information on the likely region of the state of the VMP robot within the phase space and/or may exclude the state of the VMP robot from being within some region of the phase space. For example, a depth sensor of the VMP robot may detect an obstacle in close proximity to the VMP robot. Based on this measurement and using a map of the phase space, the processor of the VMP robot may reduce the likelihood of the state of the VMP robot being any state of the phase space at a great distance from an obstacle. In another example, a reading of a floor sensor of the VMP robot and a floor map may be used by the processor of the VMP robot to adjust the likelihood of the state of the VMP robot being within the particular region of the phase space coinciding with the type of floor sensed. In an additional example, a measured Wi-Fi™ signal strength and a map of the expected Wi-Fi™ signal strength within the phase space may be used by the processor of the VMP robot to adjust the phase space probability distribution. As a further example, a Wi-Fi™ camera may observe the absence of the VMP robot within a particular room. Based on this observation the processor of the VMP robot may reduce the likelihood of the state of the VMP robot being any state of the phase space that places the VMP robot within the particular room. In some embodiments, the processor generates a simulated representation of the environment for each hypothetical state of the robot. In some embodiments, the processor compares the measurement against each simulated representation of the environment (e.g., a floor map, a spatial map, a Wi-Fi map, etc.) corresponding with a perspective of each of the hypothetical states of the robot. In some embodiments, the processor chooses the state of the robot that makes the most sense as the most feasible state of the robot. In some embodiments, the processor selects additional hypothetical states of the robot as a backup to the most feasible state of the robot. (X make sure this covers switching between FOVs).

[0480] In embodiments, the processor of the VMP robot may update the current phase space probability distribution ρ(p,q,t₁) by re-weighting the phase space probability distribution with an observation probability distribution m(p,q,t₁) according to

[0481] $\overline{\rho }\left(p,q,t_i\right)=\frac{\rho \left(p,q,t_i\right)·m\left(p,q,t_i\right)}{\int \rho \left(p,q,t_i\right)m\left(p,q,t_i\right)d\left(p,q\right)}.$
In some embodiments, the observation probability distribution may be determined by the processor of the VMP robot for a reading at time t_i using an inverse sensor model. In some embodiments, wherein the observation probability distribution does not incorporate the confidence or uncertainty of the reading taken, the processor of the VMP robot may incorporate the uncertainty into the observation probability distribution by determining an updated observation probability distribution

[0482] $\hat{m}=\frac{1-\alpha }{c}+\alpha m$
that may be used in re-weighting the current phase space probability distribution, wherein a is the confidence in the reading with a value of 0≤α≤1 and c=∫∫dpdq. For example, FIG. 137A illustrates an example of a current probability distribution 13700 and an observation probability distribution 13701. FIG. 137B illustrates the updated probability distribution 13702 after re-weighting the current probability distribution 13700 with the observation probability distribution 13701. Similarly, FIG. 137C illustrates an example of a current probability distribution 13703 and an observation probability distribution 13704. FIG. 137D illustrates the updated probability distribution 13705 after re-weighting the current probability distribution 13703 with the observation probability distribution 13704. In this example, the observation probability distribution 13704 is very narrow with a standard deviation of 0.2, indicating high confidence in the observation which is reflected in the resulting re-weighted probability distribution 13705 as it predominantly reflects the observation probability distribution 13704. In FIG. 137E the same current probability distribution 13703 is shown, however, the observation probability distribution 13706 is more spread as compared to 13704, with a standard deviation of 0.5. The resulting update probability distribution 13707 is illustrated in FIG. 137F. At any given time, the processor of the VMP robot may estimate a region of the phase space within which the state of the VMP robot is likely to be given the phase space probability distribution at the particular time.

[0483] To further explain the localization methods described, examples are provided. In a first example, the processor uses a two-dimensional phase space of the VMP robot, including position q and velocity p. The processor confines the position of the VMP robot q to an interval [0, 10] and the velocity p to an interval [−5, +5], limited by the top speed of the VMP robot, therefore the phase space (p,q) is the rectangle D=[−5, 5]×[0, 10]. The processor uses a Hamiltonian function

[0484] $H=\frac{p^2}{2m},$
with mass m and resulting equations of motion

[0485] $\stackrel{.}{p}=0\mathrm{and}\stackrel{.}{q}=\frac{p}{m}$
to delineate the motion of the VMP robot. The processor adds Langevin-style stochastic forces to obtain motion equations

[0486] $\stackrel{.}{p}=-\gamma p+\sqrt{2\gamma m{k}_{B}T}R\left(t\right)\mathrm{and}\stackrel{.}{q}=\frac{p}{m},$
wherein R (t) denotes random forces and m=1. The processor of the VMP robot initially generates a uniform phase space probability distribution over the phase space D. FIGS. 138A-138D illustrate examples of initial phase space probability distributions the processor may use. FIG. 138A illustrates a Gaussian distribution over the phase space, centered at q=5, p=0. The VMP robot is estimated to be in close proximity to the center point with high probability, the probability decreasing exponentially as the distance of the point from the center point increases. FIG. 138B illustrates uniform distribution for q∈[4.75, 5.25], p∈[−5, 5] over the phase space, wherein there is no assumption on p and q is equally likely to be in [4.75, 5.25]. FIG. 138C illustrates multiple Gaussian distributions and FIG. 138D illustrates a confined spike at q=5, p=0, indicating that the processor is certain of the state of the VMP robot.

[0487] In this example, the processor of the VMP robot evolves the phase space probability distribution over time according to Langevin equation

[0488] $\frac{\partial \rho }{\partial t}=-\left\{\rho ,H\right\}+\left(\gamma \frac{\partial }{\partial p}\right)·\left(p\rho \right)+\gamma k_{B}T\frac{{\partial }^2\rho }{\partial p^2},$
wherein

[0489] $\left\{\rho ,H\right\}=p\frac{\partial \rho }{\partial q}\mathrm{and}m=1.$
Thus, the processor solves

[0490] $\frac{\partial \rho }{\partial t}=-p\frac{\partial \rho }{\partial q}+\gamma \left(\rho +p\frac{\partial \rho }{\partial p}\right)+\gamma k_{B}T\frac{{\partial }^2\rho }{\partial p^2}\mathrm{for}t>0$
with initial condition ρ(p,q,0)=ρ₀ and homogenous Neumann perimeter conditions. The perimeter conditions govern what happens when the VMP robot reaches an extreme state. In the position state, this may correspond to the VMP robot reaching a wall, and in the velocity state, it may correspond to the motor limit. The processor of the VMP robot updates the phase space probability distribution each time a new reading is received by the processor. FIGS. 139A and 139B illustrate examples of observation probability distributions for odometry measurements and distance measurements, respectively. FIG. 139A illustrates a narrow Gaussian observation probability distribution for velocity p, reflecting an accurate odometry sensor. Position q is uniform as odometry data does not indicate position. FIG. 139B illustrates a bimodal observation probability distribution for position q including uncertainty for an environment with a wall at q=0 and q=10. Therefore, for a distance measurement of four, the VMP robot is either at q=4 or q=6, resulting in the bi-modal distribution. Velocity p is uniform as distance data does not indicate velocity. In some embodiments, the processor may update the phase space at periodic intervals or at predetermined intervals or points in time. In some embodiments, the processor of the VMP robot may determine an observation probability distribution of a reading using an inverse sensor model and the phase space probability distribution may be updated by the processor by re-weighting it with the observation probability distribution of the reading.

[0491] The example described may be extended to a four-dimensional phase space with position q=(x,y) and velocity p=(p_x,p_y). The processor solves this four dimensional example using the Fokker-Planck equation

[0492] $1\frac{\partial \rho }{\partial t}=-\left\{\rho ,H\right\}+{\nabla }_p·\left(\gamma p\rho \right)+k_{B}T{\nabla }_p·\left(\gamma M{\nabla }_p\rho \right)\mathrm{with}M=I_2$
(2D identity matrix), T=0.1, γ=0.1, and k_B=1. In alternative embodiments, the processor uses the Fokker-Planck equation without Hamiltonian and velocity and applies velocity drift field directly through odometry which reduces the dimension by a factor of two. The map of the environment for this example is given in FIG. 140, wherein the white space is the area accessible to the VMP robot. The map describes the domain for q₁, q₂∈D. In this example, the velocity is limited to p₁,p₂∈[−1, 1]. The processor models the initial probability density ρ(p,q,0) as Gaussian, wherein p is a four-dimensional function. FIGS. 141A-141C illustrate the evolution of ρ reduced to the q₁, q₂ space at three different time points (i.e., the density integrated over p₁, p₂, ρ_red=∫∫ρ(p₁,p₂,q₁,q₂)dp₁dp₂). It can be seen that with increased time, the initial density focused in the middle of the map starts to flow into other rooms. FIGS. 142A-142C illustrate the evolution of p reduced to the p₁, q₁ space and 143A-143C illustrate the evolution of ρ reduced to the p₂, q₂ space at the same three different time points to show how velocity evolves over time with position. The four-dimensional example is repeated but with the addition of floor sensor data observations. FIG. 144 illustrates a map of the environment indicating different floor types 14400, 14401, 14402, and 14403 with respect to q₁, q₂. Given that the sensor has no error, the processor may strongly predict the area within which the VMP robot is located based on the measured floor type, at which point all other hypothesized locations of the VMP robot become invalid. For example, the processor may use the distribution

[0493] $m\left(p_1,p_2,q_1,q_2\right)=\{\begin{array}{c}\mathrm{const}>0,q_1,q_2\mathrm{with}\mathrm{the}\mathrm{observed}\mathrm{floor}\mathrm{type}\\ 0,\mathrm{else}\end{array}$
If the sensor has an average error rate ϵ, the processor may use the distribution