Method for transferring information via a mobile beacon

[0001] This application is the U.S. National Stage of PCT/EP2022/060177, filed Apr. 15, 2022, which in turn claims priority to French patent application number 2103948 filed Apr. 16, 2021. The content of these applications are incorporated herein by reference in their entireties.

[0002] The field of the invention relates to the field of methods for transmitting at least one piece of information by means of a communication interface. The field of the invention is more particularly concerned with the field of methods for transmitting one or more data transmitted by a radio tag. Finally, the field of the invention is more specifically concerned with the field of methods for transmitting, by means of a mobile beacon, a location piece of data and at least one piece of data transmitted by a UWB (Ultra-Wide Band) radio tag.

[0003] In prior art, different solutions exist to ensure transmission of a piece of data of a UWB signal received. By way of example, application EP3680687 describes a method for determining the location of a UWB tag using a signal exchanged between a fixed beacon and the UWB tag and a method for adapting the signal exchanged according to the position of the UWB tag.

[0004] However, a problem persists, on the one hand when the implementation of a fixed detection infrastructure proves unsuitable for the environment or when the UWB tags are located in so-called “shadow zones”, which are zones hidden or remote from the detection infrastructure and in which UWB tags cannot be correctly detected or energized. In this respect, there is a real need to implement a solution allowing detection of UWB signals of tags positioned in these ‘shadow zones’. There is also a need to implement a UWB signal detection solution in environments where the implementation of a fixed infrastructure is not suitable, for example for reasons of financial costs or because arrangement restrictions do not allow this.

[0005] The invention detailed below solves the above drawbacks by providing a mobile UHF (Ultra-High Frequency) energy supply and UWB signal detection solution.

[0006] According to a first aspect, the invention relates to a method for transmitting a piece of information of at least one first UWB radio tag by means of a mobile beacon comprising transmission and reception means, characterized in that it comprises:

• • [0007] Transmitting a first energizing signal by means of a transmitter of an energizing signal of the mobile beacon;
  • [0008] Receiving, by the mobile beacon by means of a UWB receiver, a first UWB signal of at least the first UWB radio tag energized by the first energizing signal;
  • [0009] Recording a first decoded tag piece of data from the first UWB signal received in a memory of the mobile beacon;
  • [0010] Timestamping said reception of the first UWB signal to produce a first timestamping piece of data associated with the first piece of data;
  • [0011] Determining a first position of said mobile beacon by means of a location system;
  • [0012] Associating the first position piece of data of the mobile beacon with said first tag piece of data, said position piece of data making it possible to locate said mobile beacon,
  • [0013] Transmitting a first piece of information by the mobile beacon comprising said first tag piece of data and the first timestamping piece of data and transmitting a second piece of information by the mobile beacon comprising the first position piece of data to at least one piece of equipment of a data network.

[0014] One advantage is to be able to retrieve and transmit, for example within a data server, different information associated with a radio tag, to identify said radio tag or to associate position of the radio tag with position of the mobile beacon. Another advantage is to be able to use a UHF source to energize a radio tag located in a shadow zone which cannot be detected by a fixed infrastructure.

[0015] According to one example, the first energizing signal is a UHF signal and the transmitter of the energizing signal of the mobile beacon is a UHF transmitter.

[0016] According to one embodiment, the first piece of information is transmitted to a data server via a Wi-Fi, 4G, 5G or Bluetooth link and the second piece of information is transmitted in the form of a UWB message to a location system including at least one fixed beacon comprising means for receiving UWB signals to calculate the position of the mobile beacon by trilateration, said association between the first position piece of data of the mobile beacon and said first tag piece of data being performed by a data server and making it possible to locate said mobile beacon.

[0017] One advantage is to be able to rely on the presence of a fixed UWB detection infrastructure to calculate an accurate position of the mobile beacon in the environment.

[0018] According to one embodiment, the method comprises:

• • [0019] Transmitting a second UWB signal by the mobile beacon by means of a UWB transmitter including at least one identification piece of data of said mobile beacon encoded in said second UWB signal;
  • [0020] Receiving the second UWB signal by the location system including a plurality of UWB radio beacons including radio reception means and means for decoding a piece of information and time stamping the arrival of said second UWB signal;
  • [0021] Transmitting a detection piece of information of the second UWB signal to the mobile beacon,
  • [0022] Calculating, using all the second signals received by each of the radio beacons, a position of the mobile beacon.

[0023] One advantage is to be able to ensure that a UWB signal transmitted by the mobile beacon is actually detected by a plurality of beacons of the infrastructure.

[0024] According to one embodiment, the method comprises:

• • [0025] transmitting a plurality of second UWB signals by the mobile beacon by means of a UWB transmitter, each second UWB signal including at least one encoded piece of data for identifying said mobile beacon;
  • [0026] receiving the second UWB signals by the location system including a plurality of UWB radio beacons, said location system comprising radio reception means and means for decoding the identification piece of data and for time stamping arrival of the second UWB signals;
  • [0027] transmitting, to the mobile beacon by the location system, a piece of information of detecting the second UWB signal;
  • [0028] calculating, by means of a plurality of second signals received by each of the radio beacons, the first position piece of data of the mobile beacon.

[0029] According to one embodiment, the method comprises:

• • [0030] Transmitting the second UWB signal by the mobile beacon including at least one identification piece of data of said mobile beacon encoded in said second UWB signal, said transmitting automatically generating transmitting the detection piece of information by a UWB system when the latter receives said identification piece of data,
  • [0031] Transmitting a plurality of second UWB signals at an increased frequency during a second time interval in case of non-reception of the detection piece of information at the end of a first time interval.

[0032] According to one embodiment, the method comprises:

• • [0033] transmitting a second UWB signal by the mobile beacon by means of a UWB transmitter, said second UWB signal comprising at least one encoded piece of data of identifying said mobile beacon, said transmitting resulting in activating a clock to measure a first time interval,
  • [0034] transmitting a plurality of second UWB signals at an increased frequency during a second time interval in case of non-reception of a detection piece of information at the end of a first time interval, said detection piece of information indicating detection of the second UWB signal by a UWB reception system.

[0035] One advantage is to ensure that the mobile beacon is actually detected by the detection infrastructure when the first UWB signal transmitted has not allowed said detection of the mobile beacon.

[0036] According to one embodiment, the first piece of information and the second piece of information are transmitted to a data server by a wireless communication interface, the association between the first position piece of data of the mobile beacon and the first tag piece of data being performed within the mobile beacon, said first position piece of data being transmitted to the mobile beacon by a location system.

[0037] One advantage is to be able to associate position of the mobile beacon with position of a UWB tag originating transmitting a UWB signal comprising the first tag piece of data.

[0038] According to one embodiment, the first position piece of data is transmitted by:

• • [0039] A reference tag having known position;
  • [0040] A satellite geolocation system;
  • [0041] A geolocation system by geocoder;
  • [0042] A Wi-Fi geolocation system;
  • [0043] A geolocation system by use of a telecommunications operator,
  • [0044] An RFID geolocation system.

[0045] One advantage is to be able to adapt the location system to the context in which the mobile beacon operates. For example, a location system comprising a reference tag will be more suitable in an indoor environment than satellite geolocation.

[0046] Optionally, the mobile beacon B_M receives the first position piece of data.

[0047] According to one embodiment, the method comprises:

• • [0048] Transmitting a third UWB signal comprising a first time piece of information and a second piece of information by at least one UWB radio tag with a known position reference;
  • [0049] Receiving the third UWB signal by the mobile beacon;
  • [0050] Recording the first time piece of information and the second piece of data decoded from the UWB signal received in a memory of the mobile beacon;
  • [0051] Timestamping said reception of the third UWB signal to produce a second timestamping piece of data associated with receiving the time piece of information and the second piece of data,
  • [0052] Transmitting a third piece of information comprising the first time piece of information, the second piece of data and the second timestamping piece of data to at least one piece of equipment in the data network.

[0053] One advantage is to be able to calculate a travel time of a UWB signal between a reference tag having known position and the mobile beacon.

[0054] According to one embodiment, the method comprises:

• • [0055] receiving, by the mobile beacon and by means of a UWB receiver, a third UWB signal transmitted by at least one reference UWB radio tag having known position, said third UWB signal comprising a first encoded time piece of information of time stamping the transmission of said third UWB signal and comprising a second encoded identification piece of data of the reference UWB radio tag;
  • [0056] time-stamping said reception of the third UWB signal to produce a second piece of data of timestamping reception of the time piece of information and the second piece of data,
  • [0057] recording the first decoded time piece of information and the second decoded identification piece of data in a memory of the mobile beacon;
  • [0058] transmitting, by the mobile beacon, a third piece of information comprising the first time piece of information, the second piece of data and the second timestamping piece of data to at least one piece of equipment of the data network.

[0059] According to one embodiment, the method comprises:

• • [0060] Transmitting, by the mobile beacon and by a plurality of UWB radio beacons, a plurality of third pieces of information each comprising the first time piece of information, the second piece of data and a timestamping piece of data by means of a communication interface to at least one piece of equipment of the data network;
  • [0061] Determining for the mobile beacon and for each UWB radio beacon a propagation time piece of information of each third UWB signal, said propagation time piece of information being determined on the basis of the first time piece of information and the timestamping piece of data;
  • [0062] Comparing the propagation time information of each third UWB signal by means of a comparator,
  • [0063] Synchronizing the clocks of the mobile beacon and the UWB radio beacons with each other according to the propagation time information of each third UWB signal

[0064] One advantage is to synchronize clocks of a plurality of mobile or fixed beacons to allow implementation of position calculations by trilateration.

[0065] According to one embodiment, the method comprises:

• • [0066] transmitting, by the mobile beacon and by a plurality of UWB radio beacons, a plurality of third pieces of information via a communication interface and to at least one piece of equipment of the data network;
  • [0067] calculating, for the mobile beacon and for each UWB radio beacon and by means of a calculator, a propagation time piece of information of each third UWB signal, each propagation time piece of information being calculated from each first time piece of information and each second timestamping piece of data;
  • [0068] comparing, by a comparator, the propagation time information of each third UWB signal,
  • [0069] synchronizing a clock of the mobile beacon and a clock of each UWB radio beacon between them according to the result of comparisons of the propagation time information.

[0070] According to one embodiment, the method comprises implementing at least one calculation of a relative position of at least the first UWB radio tag per trilateration, said calculation being implemented by means of a calculator on the basis of at least one first UWB signal transmitted by the first UWB radio tag and received by the mobile beacon and by at least two UWB radio beacons.

[0071] According to one embodiment, the method comprises implementing, by means of a calculator, at least one calculation by trilateration of a relative position of the first UWB radio tag, from the first UWB signal transmitted by said first UWB radio tag and received by the mobile beacon and by at least two other UWB radio beacons.

[0072] One advantage is to use the mobile beacon to perform at least one calculation of a position of an object by trilateration when the position of said mobile beacon is known.

[0073] According to one embodiment, the method comprises

• • [0074] Receiving a first amount of UHF energy by the mobile beacon by means of a UHF receiver;
  • [0075] Comparing, by means of a comparator, the first amount of UHF energy received with a predetermined threshold energy value;
  • [0076] Transmitting the first energizing UHF signal using the UHF transmitter by the mobile beacon if the first amount of UHF energy received is below the predetermined threshold energy value,
  • [0077] Reducing the energy transmitted by the UHF transmitter of the mobile beacon if the first amount of UHF energy received exceeds the predetermined threshold energy value.

[0078] One advantage is to be able to “map” the UHF energy of several zones and supply the weakest supplied zones with UHF energy. Advantageously, transmitting the first UHF signal may result in transmitting UWB signals by tags present in the initially low-energized zone.

[0079] According to one embodiment, the method comprises:

• • [0080] Measuring a distance value between an object and the mobile beacon by means of a distance sensor;
  • [0081] Comparing the distance value measured with a predetermined threshold distance value,
  • [0082] Modulating transmission of the first UHF energizing signal by the UHF transmitter of the mobile beacon if the distance value measured is below the predetermined threshold distance value.

[0083] Advantageously, overall energy consumption can be reduced by reducing the transmitted signal power when the UHF energy supply source is close to a UWB radio tag to be energized.

[0084] According to one embodiment, the first UWB signal received is associated with a context piece of information, said context piece of information being processed by processing means to determine an identification piece of data of at least one mobile beacon having transmitted a first UHF energizing signal originating the transmission by the first UWB radio tag of said first UWB signal received by the mobile beacon.

[0085] According to one embodiment, the first UWB signal received by the mobile beacon is associated with a context piece of information corresponding to a piece of information on the environment in which the mobile beacon operates, and in which the first piece of information transmitted to the equipment of a data network comprises the context piece of information, the context piece of information being processed by processing means to determine an identification piece of data of the mobile beacon having transmitted the first energizing signal originating transmission by the first UWB radio tag of said first UWB signal received by said mobile beacon.

[0086] One advantage is to be able to precisely identify a mobile beacon according to different physical parameters measured, for example, by means of sensors.

[0087] According to another aspect, the invention relates to a mobile beacon comprising transmission and reception means configured to implement the method according to any of the aforementioned embodiments.

[0088] According to another aspect, the invention relates to a mobile beacon comprising means for transmitting an energizing signal, means for receiving UWB signals, a calculator, and a memory, and configured to implement the method according to any of the aforementioned embodiments.

[0089] According to one embodiment, the mobile beacon comprises at least two transmission antennas, each transmission antenna being configured to transmit at least one portion of the first energizing UHF signal. One advantage is to be able to supply a plurality of radio tags, each located at different positions, with UHF energy. Another advantage is to increase the UHF coverage of the mobile beacon when controlling directionality of the UHF beam is made difficult by the hardware configuration, for example when the mobile beacon is mounted to a mobile cart.

[0090] According to another aspect, the invention relates to a mobile cart including a mobile beacon according to any of the aforementioned embodiments.

[0091] According to another aspect, the invention relates to an element embedded by a user comprising a mobile beacon.

[0092] According to another aspect, the invention relates to a system comprising a mobile beacon according to any of the aforementioned embodiments and including at least one first UWB radio tag.

[0093] Optionally, the first radio tag is configured to transmit the first UWB signal.

[0104] FIG. 1 describes a method for transmitting a piece of information of at least one first radio tag UWB by means of a mobile beacon B_M according to a first aspect of the invention when the mobile beacon B_M comprises transmission and reception means.

UHF Transmitter of the Mobile Beacon

[0105] According to one embodiment, the mobile beacon B_M comprises an energy transmitter. The energy transmitter is, for example, a UHF (ultra-high frequency) transmitter EM_UHF. In the remainder of the description, the energy transmitter of the mobile beacon B_M will be described with the example of a UHF transmitter. However, any type of transmitter intended to provide energy at various frequencies to supply a receiver is likely to be implemented within the scope of the invention. The UHF transmitter EM_UHF is configured to transmit a first energizing UHF signal S_UHF1. According to one example, the first UHF signal S_UHF1 is transmitted at radio frequencies between 25 MHz and 5 GHZ and more particularly in the range from 225 MHz to 3400 MHZ. According to various examples, the frequency range operated comprises a WI-FI range or even an RFID (Radio Frequency Identification) range. More generally, any available frequency range having power is likely to be operated.

[0106] According to one embodiment with reference to FIG. 1, the UHF transmitter is configured to transmit the first UHF signal S_UHF1 toward a first radio tag ET₁. The first radio tag ET₁ then comprises reception means for receiving said energizing signal S_UHF1. One advantage is to provide radioelectric energy to the radio tag to enable it to transmit a signal, in particular a UWB signal when the tag comprises UWB transmission means.

[0107] According to one embodiment, the UHF transmitter EM_UHF comprises a plurality of transmission antennas. For example, each transmission antenna is oriented in a different direction than the other transmission antennas. According to one alternative, the transmission antennas are oriented in the same direction. Each transmission antenna is configured to transmit at least one part of the energizing UHF signal S_UHF1.

[0108] One advantage is to be able to provide UHF energy to multiple radio tags, each located in different positions. Another advantage is to increase the UHF coverage of the mobile beacon when controlling the UHF beam directionality is made difficult by the hardware configuration, for example when the mobile beacon is made integral with an element likely to move such as a mobile cart.

[0109] In one embodiment, the plurality of transmission antennas comprises a phased-array antenna. The phases of the signals supplying each of the antennas can be adjusted, for example to obtain a specific radiation diagram.

[0110] In one embodiment, the power of the UHF signal delivered by each of the antennas is modulable. By “Modulable”, it is meant that the intensity or power of the UHF signal delivered by one of the antennas can be controlled, for example by control means. The control means can be controlled by a user. Controlling by a user is for example implemented by means of a user interface of an electronic device comprising the mobile beacon B_M or paired with said mobile beacon B_M. In one embodiment, the control means are configured to control at least one transmission antenna. By “control”, it is meant both “modulating the UHF signal delivered by a transmission antenna” and shutting down a transmission antenna. By “shutting down”, it is meant that a transmission antenna no longer delivers the first energizing UHF signal S_UHF1. This configuration is particularly advantageous for concentrating the first UHF signal S_UHF1 at the output of a single transmission antenna when a UWB tag is facing said transmission antenna. The position of the mobile beacon B_M can then advantageously be associated with the position of the tag originating the transmission of said UWB signal.

[0111] In one embodiment, each antenna of the plurality of transmission antennas is configured to deliver part of the first energizing UHF signal S_UHF1. This is particularly advantageous to allow a wider UHF coverage in the transmission zone, especially when a UWB tag to be energized has not yet been located.

UWB Receiver of the Mobile Beacon

[0112] According to one embodiment, the mobile beacon B_M comprises a UWB (Ultra-Wide Band) receiver REC_UWB. The UWB receiver REC_UWB is capable of receiving at least one UWB signal. The UWB signal received may for example be a first signal UWB signal S_UWB1 from the first UWB tag ET₁ energized by the first UHF signal S_UHF1.

[0113] One advantage is to be able to associate position of the first UWB tag ET₁ originating the transmission of the UWB signal S_UWB1 with a position of the mobile beacon B_M. Another advantage is to be able to determine movement of the mobile beacon B_M according to the transmission frequency of the first UWB tag ET₁. For example, the increase in the transmission frequency of the first UWB tag ET₁ can be associated with the mobile beacon BM moving closer to said first UWB tag ET₁ and the decrease in the transmission frequency of the first UWB tag ET₁ can be associated with the mobile beacon B_M moving away from said first UWB tag ET₁.

[0114] In one embodiment, the UWB receiver REC_UWB of the mobile beacon B_M comprises at least one receiving antenna UWB. Each receiving antenna UWB may be oriented at a predetermined angle relative to the direction along which any of the other receiving antennas UWB extends. One advantage is to improve reception of the UWB signals by the UWB receiver REC_UWB of the mobile beacon, in particular by increasing the reception spatial coverage of the receiving antennas UWB. Another advantage is to be able to determine more precisely position of a UWB tag according to the angle of arrival of the UWB signal transmitted by said UWB tag and received by at least one receiving antenna of the UWB receiver of the mobile beacon.

[0115] In one embodiment, the UWB receiver REC_UWB of the mobile beacon B_M comprises a phased-array antenna. This embodiment is particularly advantageous for obtaining spatial selectivity on radio signals by “beamforming” or “spatial filtering”. These expressions are better known in Anglo-Saxon literature as beamforming.

[0116] According to one embodiment, the mobile beacon B_M comprises a calculator. The calculator is configured to calculate, for each receiving antenna of the UWB receiver REC_UWB of the mobile beacon B_M, power of the first UWB signal S_UWB1 received. One advantage is to be able to correlate power received by each antenna with the angle of arrival of the first UWB signal S_UWB1 received to improve locating the UWB tag originating the transmission of said first UWB signal S_UWB1.

[0117] In one embodiment, transmitting the first signal UHF₁ by the UHF transmitter EM_UHF of the mobile beacon causes the reception of the first UWB signal S_UWB1 by the UWB receiver RE_UWB of the mobile beacon B_M. According to one illustrative example, the first UHF signal S_UHF1 transmitted is then received by the first UWB tag ET₁ which then automatically, and preferably spontaneously, transmits the first UWB signal S_UWB1 in response to the energy input provided by receiving the first UHF signal S_UHF1. The spontaneous transmission of a UWB signal by the UWB tag ET₁ is triggered as soon as a sufficient level of radio frequency energy is collected. The first UWB signal S_UWB1 transmitted by the first UWB tag ET₁ is then received by the UWB receiver REC_UWB of the mobile beacon B_M.

First Tag Piece of Data D1

[0118] According to one embodiment, the first UWB signal S_UWB1 comprises a first tag piece of data D₁. The first tag piece of data D₁ further comprises information specific to the first tag ET₁ originating the transmission of the first UWB signal S_UWB1. The information included in the first piece of data D₁ includes, for example, position of the first tag ET₁ or even information on an object to which said first tag ET₁ is affixed, for example a parcel or luggage.

[0119] The first tag piece of data D₁ received by the mobile beacon B_M is recorded in a memory MEM of the mobile beacon B_M. The reception of the first UWB signal S_UWB1 comprising the first tag piece of data D₁ is timestamped to produce a first timestamping piece of data H₁ associated with said first piece of data D₁.

Identification of the Mobile Beacon Position

[0120] With reference to FIG. 2, the invention aims to associate position of the mobile beacon B_M with a first piece of data D₁ transmitted by a radio tag. The association can be carried out deferred or in real time depending on the system implemented. Thus, it is possible to deduce position of the first radio tag ET₁ from the calculated position of the mobile beacon that “saw” the tag that is ultimately being sought to be located.

[0121] To achieve this result, the invention allows the position of the mobile beacon B_M to be measured or calculated. Different locating techniques can be implemented. These different locating techniques may involve the mobile beacon playing a more or less active role in the production of data for locating it. According to some cases, the beacon does not know its position but transmits data enabling it to be located by a third-party system. In some cases, the mobile beacon B_M calculates or receives its position so as to associate it directly with the first piece of data D₁ transmitted by the tag ET₁.

[0122] In the remainder of the description, different locating systems are described according to different embodiments of the invention.

Associating Position of the Mobile Beacon and of the Radio Tag

[0123] In one embodiment, the first position piece of data POS₁ is associated with the position of at least one UWB tag energized by the first UHF energizing signal S_UHF1. The association can be performed within the memory MEM of the mobile beacon B_M. In this case, the data associated can be transmitted in real time or delayed by the beacon to a third-party system. Association can also be carried out within a piece of equipment of a data network NET. This a posteriori association involves data transmission and processing for reconstructing the association context between the mobile beacon B_M and the first UWB tag ET₁. For example, timestamping, position, or other data used to a posteriori calculate the position of the UWB tag ET₁.

Location System

[0124] The position of the mobile beacon B_M is determined by means of a location system L_GEO.

[0125] According to one embodiment, the location system L_GEO comprises means for transmitting a first position piece of data POS1 of the mobile beacon B_M which can be operated by a system. Operating may comprise reconstructing a position, associating a first position piece of data POS₁ of the mobile beacon B_M with a tag piece of data or retransmitting said first position piece of data POS₁ to the mobile beacon B_M or to a server for a posteriori operating this piece of data.

[0126] Different locating techniques can be implemented. For example, the location system L_GEO may comprise a reference tag ET_ref having known position or a satellite positioning system, also called GNSS (Global Navigation Satellite System). According to various non-limiting examples, the GNSS system comprises a GPS, GLONASS, BEIDU or Galileo system.

[0127] In one embodiment, the GNSS system is coupled to a positioning improvement system. According to various examples cited by way of non-limiting purposes, the positioning improvement system comprises a system of the SBAS type, or even a GBAS system. In some cases, such a system operates connectivity of the mobile beacon B_M (4G, Wi-Fi, LoRa, etc.)

[0128] Other location techniques may be implemented. For example, the location system L_GEO may comprise a geocoder geolocation system, a Wi-Fi geolocation system, a geolocation system by the use of a telecommunication operator, an odometry location system, or even a Radio Frequency Identification (RFID) geolocation system. According to different examples, the location system by using a telecommunications operator comprises, for example, the use of a LoRa technology or even a GSM (“Global System for Mobile communications”) technology.

[0129] In one embodiment, the location system L_GEO comprises a “quick response code”, or even “QR code”. For example, this quick response code is positioned in the detection environment to a position known to the system. According to different non-limiting examples, the code is positioned on a wall, floor, ceiling, crate, or any other fixed position element in the detection enviornment.

[0130] In one case, the location system L_GEO comprising said quick response code is scanned by a device configured to decode information contained in said code. Such a device is for example embedded by a user or embedded by the mobile beacon B_M. In this case, the scanned information is then transmitted to the equipment of the data network NET by means of the communication interface INTc.

[0131] Advantageously, a link can then be established between the decoded and transmitted information and the geographical position of the code known by the system to deduce position of the user or of the mobile beacon B_M which scans said code.

[0132] In one embodiment, the quick response code contains location data. These data include, for example, terrestrial coordinates corresponding to the position of said code in the location environment. In this case, a user or a mobile beacon B_M embedding a scanner to decode said code can transmit the scanned data to a piece of equipment on the data network NET, for example by means of the communication interface INTC. Advantageously, it is not necessary to make the link between the transmitted data and a position known to the system in that the transmitted information already includes the position data of said code.

[0133] According to different embodiments, the quick response code is scanned by means of different sensors such as sensors comprising laser technologies, optical sensors for example by means of a camera. These examples are not limiting and any type of technologies comprising means for decoding data stored in a quick response code are likely to be implemented in the scope of the invention.

[0134] In one example, a video acquisition system comprising a camera is implemented to acquire an image or a video sequence of a zone of the detection environment comprising a location system L_GEO comprising a quick response code. The video acquisition system is for example embedded by the mobile beacon B_M, by a mobile cart embedding the mobile beacon B_M or by a user.

[0135] Thus, the “view angle” of the image or video sequence acquired on which one or more quick response codes appear advantageously makes it possible to determine or confirm a position of the mobile beacon B_M or the user, or to determine an orientation piece of information.

[0136] According to another embodiment, the mobile beacon B_M comprises a camera configured to detect particular wavelengths, for example an infrared camera. For example, the camera is embedded on a mobile beacon B_M itself embedded by a user. For example, the camera is positioned on the top of the mobile beacon B_M. In one case, the camera senses specific wavelengths from sources positioned in specific zones. The mobile beacon B_M equipped with the camera can then recognize particular patterns or particular wavelengths to determine its position. In another example, an image or video sequence acquired by the camera is operated and analyzed using a calculator to determine a position, orientation, or path of the mobile beacon B_M as a function of time.

[0137] However, the elements included in the location system L_GEO are not limited to the above-mentioned examples and may comprise any type of elements capable of contributing to the location of an object in space; or even a combination of these different elements, for example to improve accuracy of the location or cover a larger zone than with a single location technique.

Location by a UWB System (Fixed Beacons)

[0138] In one embodiment, the position of the mobile beacon B_M is calculated by trilateration by a plurality of beacons. These beacons are also called “fixed beacons” to differentiate them from the mobile beacon B_M.

[0139] Each beacon includes UWB reception means configured to receive at least one second UWB signal S_UWB2 transmitted by the mobile beacon B_M. For example, the second UWB signal S_UWB2 comprises at least one identification piece of data of the mobile beacon B_M encoded in said second UWB signal S_UWB2. This configuration is particularly advantageous for locating the mobile beacon B_M in an indoor environment, particularly when a detection architecture comprising a plurality of beacons is set up and localization by another system such as a GNSS system is not suitable.

[0140] In one embodiment, the mobile beacon B_M is configured to transmit the second UWB signals S_UWB2 several times. The successive transmissions allow ensuring reception of said second UWB signal S_UWB2 by the fixed beacons in order to increase probability of detection of the mobile beacon. According to one case, the transmissions of the mobile beacon are performed according to a periodic frequency. This case may be implemented in particular when the mobile beacon includes a battery enabling it to make use of sufficient electric energy to generate successive transmissions. Advantageously, the detections of the second signals S_UWB2 successively by a plurality of beacons present in the detection environment are improved, thus improving the location accuracy of the mobile beacon B_M in the detection environment.

[0141] In another embodiment, time filtering is implemented on the second UWB signals S_UWB2 transmitted successively by the mobile beacon B_M. One advantage is to oversample the calculated position from said second UWB signals S_UWB2, for example to eliminate a location noise.

[0142] According to one exemplary embodiment, the plurality of beacons is configured to calculate position of the mobile beacon B_M by trilateration to produce the first position piece of data POS₁. The first position piece of data POS₁ can then be operated in different ways so that it is associated with the first tag piece of data D₁. The association can be made:

• • [0143] at a fixed beacon when the first tag piece of data D₁ is retrieved by the latter.
  • [0144] at a third-party piece of equipment such as a server when the latter receives by the UWB location system the first position piece of data POS₁ and receives by another data transmission system the first tag piece of data D₁.
  • [0145] at the mobile beacon B_M when the position of beacon B_M calculated by trilateration is retransmitted to the mobile beacon B_M.

[0146] In a first case, the association between the first tag piece of data D₁ and the first position piece of data POS₁ is carried out at a fixed beacon. In this first case, the second UWB signal S_UWB2 is transmitted by the mobile beacon B_M and includes the first tag piece of data D₁ and the first timestamping piece of data H₁. The second UWB signal S_UWB2 is then received by a fixed beacon or a plurality of fixed beacons. The position of the mobile beacon B_M is calculated by trilateration by the plurality of fixed beacons to produce the first position piece of data POS₁. The first position piece of data POS₁ is then associated with the first tag piece of data D₁ within a memory of one of the fixed beacons.

[0147] In a second case, the association between the first tag piece of data D₁ and the first position piece of data POS₁ is performed at a third-party piece of equipment such as a piece of equipment of a data network NET. In this case, the first position piece of data POS₁ is calculated by trilateration by a plurality of beacons and the first position piece of data POS₁ is then transmitted by the plurality of beacons to the piece of equipment of the data network NET. The first piece of information S_trans1 comprising the first tag piece of data D₁ as well as the first timestamping piece of data H₁ is transmitted by the mobile beacon B_M to the piece of equipment of the data network NET. Thus, the association between the first position piece of data POS₁ calculated by trilateration by the plurality of fixed beacons and the first tag piece of data D₁ transmitted by the mobile beacon B_M can be a posteriori carried out retrospectively at the piece of equipment of the data network NET.

[0148] In a third case, the association between the first position piece of data POS₁ and the first tag piece of data D₁ is performed within the mobile beacon B_M. In this case, the first position piece of data POS₁ can come from different sources. The first position piece of data POS₁ can come from a reference tag having known position ET_ref and transmitted within a UWB signal to the mobile beacon B_M after said reference tag ET_ref has been energized by the UHF transmitter EM_UHF of the mobile beacon B_M. According to different embodiments, the reference tag ET_ref is supplied by an electric energy storage device such as a battery, by an AC/DC power supply or even by an external DC power supply such as, for example, a “Power Over Ethernet” (POE). However, the above examples are given by way of indicating and in no way limiting purposes. More generally, any type of power supply is likely to be implemented to supply the reference tag ET_ref. According to other examples, the first position piece of data POS₁ comes from a GNSS location system or even from a plurality of fixed beacons having calculated position of the mobile beacon by trilateration. Generally speaking, in this third case, the first position piece of data POS₁ may come from any of the location systems L_GEO described previously. The association between the first tag piece of data D₁ and the first position piece of data POS₁ is then performed in the memory MEM of the mobile beacon B_M. The mobile beacon B_M can then advantageously transmit the first piece of information S_trans1 comprising the first tag piece of data D₁ associated with said first position piece of data POS₁ to a piece of equipment of a data network NET.

Location by a Sensor Located on the Mobile Beacon

[0149] In one embodiment, the first position piece of data POS₁ is determined from one or more sensors embedded by the mobile beacon B_M. The sensors embedded by the mobile beacon B_M may include, for example, an inertia unit or a laser rangefinder. However, sensors used to determine the position of the mobile beacon B_M are not limited to the aforementioned examples and may comprise any other type of sensor or a combination of several sensors together. One advantage is to obtain a piece of information on the position of the mobile beacon B_M when the use of other location systems is not optimized, for example when the beacon is in an indoor environment and the use of a GNSS system is unsuitable. Another advantage is to be able to combine the information from the sensors with other information from other location systems to improve accuracy of locating the mobile beacon B_M.

[0150] In one embodiment, the first position piece of data POS₁ comprises a piece of information from at least one sensor embedded by the mobile beacon B_M and a piece of information from a signal received by the mobile beacon B_M. For example, the signal received may comprise the first UWB signal S_UWB1 from the first UWB tag ET₁ located in proximity to the mobile beacon B_M. According to one example, an association of the piece of information from the at least one sensor embedded by the mobile beacon B_M and the signal received by said mobile beacon is performed within the memory MEM of the mobile beacon B_M. Advantageously, accuracy of the calculation of the position of the mobile beacon B_M is improved. Another advantage is to be subsequently able to use the mobile beacon B_M whose position is precisely known within a constellation of beacons to implement position calculations by trilateration.

Detection of the UWB Signal Transmitted by the Mobile Beacon

[0151] In one embodiment, with reference to FIG. 3, the second UWB signal S_UWB2 transmitted by the mobile beacon B_M is received by the location system L_GEO comprising the plurality of beacons. The plurality of beacons comprises radio reception means, means for decoding a piece of information and means for timestamping arrival of the UWB signal S_UWB2. The plurality of beacons is configured to transmit a detection piece of information INF_D of the second UWB signal S_UWB2 to a third-party piece of equipment or to the mobile beacon B_M. The detection piece of information may be an acknowledgement transmitted to the mobile beacon and/or may be a piece of information relating to the quality of reception of the signal received by a fixed beacon and retransmitted to the mobile beacon B_M or to a third-party piece of equipment.

[0152] When the detection piece of information INF_D is transmitted to the beacon, it may further comprise a piece of information, by the plurality of beacons, of receiving the UWB signal S_UWB2 previously transmitted by the mobile beacon B_M. One advantage is to know whether the signal transmitted by the mobile beacon B_M is actually detected by the plurality of beacons.

[0153] In one embodiment, with reference to FIG. 4, the mobile beacon B_M is configured to transmit a plurality of second UWB signals at an increased frequency F_burst in case of non-reception of the detection piece of information INF_D. Transmission of the plurality of UWB signals can occur in case of non-reception of the detection piece of information INF_D after a first time interval ΔT₁. The transmission of the plurality of second UWB signals can take place during a second time interval ΔT₂. The two time intervals ΔT₁ and ΔT₂ may have been parameterized upstream by a user, for example, using a configuration console for configuring transmission variables of the beacon. Transmission of the plurality of UWB signals at the increased frequency F_burst can also come from a command sent by a piece of equipment of a data network NET. One advantage is to ensure detection of the mobile beacon B_M by a beacon or a constellation of beacons when the first second UWB signal S_UWB2 has not been detected first.

[0154] In one alternative, transmission of the plurality of second UWB signals ends when the mobile beacon B_M receives the detection piece of information INF_D.

Synchronization of Clocks of the Beacons and Position Calculation

[0155] The invention makes it possible to take account of a synchronization signal generated by reference equipment, the relative position towards reception beacons or fixed beacons of which is known. This last signal makes it possible to synchronize the different beacons with each other in order to minimize errors and to precisely calculate the position of a mobile beacon B_M and therefore the radio tag whose position is sought to be obtained via the mobile beacon B_M.

[0156] Different synchronization techniques may be used within the scope of the invention. According to one example, this signal can be transmitted from a reference radio tag ET_ref whose position is known to the system.

[0157] According to one embodiment, with reference to FIG. 5, the method according to the invention comprises transmitting, by a reference tag ET_ref, a third UWB signal S_UWB3 comprising a first time piece of information T₁ and a second tag piece of data D₂. Transmitting the third UWB signal S_UWB3 is conditioned by the power supply of said reference tag ET_ref by an energy source. According to various examples, the energy supply source implemented to supply the reference tag ET_ref comprises a UHF source or an electric energy supply source such as a battery or even an external source. The external source is, for example, AC/DC power supply, power supply via Ethernet cable or power supply via solar panels. In one alternative, the energy supply source of the reference tag ET_ref comprises a combination of several of these technologies. In one example, the UHF energy source is the UHF transmitter EM_UHF of the mobile beacon B_M. The time piece of information T₁ comprises, for example, timestamping of the transmission of the third UWB signal S_UWB3. The second tag piece of data D₂ comprises, for example, a piece of information on the position of the reference tag ET_ref or even an identification piece of information of said reference tag ET_ref.

[0158] According to one embodiment, the third UWB signal S_UWB3 is received by the mobile beacon B_M by means of the UWB receiver REC_UWB. Receiving said third signal S_UWB3 is then timestamped to produce a second timestamping piece of data H₂ associated with receiving, by the mobile beacon B_M of the second tag piece of data D₂ and the first timestamping piece of data D₁. In this case, the mobile beacon B_M can then transmit a third piece of information S_trans3 comprising the first time piece of information T₁, the second tag piece of data D₂ and the second timestamping piece of data H₂ to at least one piece of equipment of a data network NET. One advantage is to be able to deduce, from the first time piece of information T₁ and the second timestamping piece of data H₂, the travel time of the signal transmitted by the reference tag ET_ref to the mobile beacon B_M.

[0159] The synchronization signals can be directly operated by the beacons or a posteriori operated by a third-party piece of equipment in order to reconstruct positions of the mobile beacon B_M and/or the radio tag ET₁. In one embodiment, the mobile beacon B_M and a plurality of UWB radio beacons are configured to each transmit a third piece of information S_trans3. Each third piece of information S_trans3 comprises the first time piece of information T₁ comprising timestamping of the transmission of the third UWB signal S_UWB3 from the reference tag ET_ref. Each third piece of information S_trans3 also includes the second piece of data D₂ and a timestamping piece of data, said timestamping piece of data comprising timestamping, for each of the beacons, of the reception of the third signal UWB S_UWB3 from the reference tag ET_ref. For example, each third piece of information S_trans3 is transmitted to a piece of equipment of a data network NET. A propagation time piece of information of the third UWB signal S_UWB3 is then determined for each of the beacons. The propagation time piece of information can be determined from the timestamping piece of data produced after reception of the third UWB signal S_UWB3 by one of the beacons and from the first time piece of information T₁, for example by subtracting the time of transmission of the third UWB signal S_UWB3 from the time of reception of said third UWB signal S_UWB3. In this example, the propagation time piece of information then comprises the travel time of the third UWB signal S_UWB3 from its transmission by the reference tag ET_ref until its reception by one of the beacons or by the mobile beacon B_M. This means that the entire location system can be coordinated and synchronized by sending a synchronization signal for each beacon.

[0160] In one embodiment, the mobile beacon B_M and/or one of the beacons comprises calculation means configured to determine the propagation time piece of information from the timestamping piece of data and the first time piece of information T₁, said propagation time piece of information comprising the travel time of the third UWB signal S_UWB3 between the reference tag ET_ref and the beacon comprising said calculation means. This advantageously enables the calculation of the propagation time of the third UWB signal S_UWB3 to be implemented directly within the beacons so as to be able to transmit the propagation time piece of information via the third piece of information S_trans3 subsequently transmitted. In one alternative, calculating the propagation time piece of information is subsequently implemented, after receiving the third piece of information S_trans3 by a piece of equipment of a data network NET.

[0161] In one embodiment, calculating the propagation time piece of information is implemented for each of the beacons. Calculating the propagation time piece of information can also be implemented for the mobile beacon B_M. Each propagation time piece of information includes the travel time of the third UWB signal S_UWB3 between the reference tag ET_ref originating its transmission and each of the beacons. Each propagation time piece of information can then be compared, for example by means of a comparator, to determine the different travel times of the third UWB signal S_UWB3 between the reference tag Et_ref originating its transmission and each of the beacons. Advantageously, this allows the clocks of the different beacons to be synchronized with each other to enable the use of the beacons in the implementation of subsequent calculations, for example, calculations of the position of an object by trilateration.

Trilateration with the Mobile Beacon

[0162] In one embodiment, calculating the position of at least one radio tag UWB ET₁ is implemented by trilateration, said trilateration being implemented by means of the mobile beacon B_M and by means of at least two beacons. In this embodiment, the position of the mobile beacon B_M has previously been precisely determined, for example by means of the location system S_GEO.

[0163] One advantage is to be able to use a mobile beacon in implementing position calculations by trilateration, when the precise position of the mobile beacon B_M has been determined, for example by means of the location system S_GEO. Another advantage is to improve location precision of a pre-existing fixed detection infrastructure by adding a beacon with a specific position to the location infrastructure.

[0164] In one embodiment, at least one mobile beacon B_M having known position is implemented in a method for calculating a position of at least one second mobile beacon B_M. Determining the position of the second mobile beacon B_M advantageously enables said second mobile beacon B_M to be used in the subsequent implementation of calculations of the position of an object by trilateration. Another advantage is to be able to track the movement of one or a plurality of mobile beacons over time by implementing position calculations at regular time intervals.

Data Exchange Between the Mobile Beacon and the Data Network

[0165] According to one embodiment, the mobile beacon B_M comprises means for transmitting a first piece of information S_trans1. The first piece of information S_trans1 comprises the first tag piece of data D₁ and the first timestamping piece of data H₁ associated with said first tag piece of data D₁. The first piece of information S_trans1 is transmitted to a data server by non-wireless communication means. In one example, the non-wireless communication means include a Wi-Fi, 4G, 5G or even Bluetooth link. One advantage is to be able to store on a data server information related to an object or parcel to which the tag ET₁ originating transmission of the first tag piece of data D₁ is affixed.

[0166] In one embodiment, the first piece of information S_trans1 is sent continuously to a piece of equipment of a data network NET. This is made possible in particular when the mobile beacon B_M is permanently connected to the data network NET via the non-wired connection means.

[0167] In one embodiment, the mobile beacon B_M is configured to receive data from a piece of equipment of the data network NET. This scenario is advantageous when a user wishes to determine position of a radio tag ET₁ and wishes to access the information system managing all the positions of the tags from their mobile beacon. Thus, the mobile beacon B_M can act as an access terminal to the data of the radio tags, for example by means of a user interface connected to said mobile beacon B_M. This is made possible when the mobile beacon B_M is connected to a piece of equipment of the data network NET by the non-wired connection means.

[0168] According to one embodiment, the mobile beacon B_M can store data received from the piece of equipment of the data network NET within its memory MEM. The data received may, for example, include recent data stored on the piece of equipment of the data network NET by another mobile or fixed beacon. One advantage is to establish a bidirectional link between the mobile beacon B_M and the piece of equipment of the data network NET in order to be able to receive updated information on several elements of the system, for example position of other mobile beacons or information on UWB tags that have recently been energized.

UHF Mapping by the Mobile Beacon

[0169] In one embodiment, the method according to the invention comprises receiving a first amount of UHF energy B_UHF1 by the mobile beacon B_M. Receiving the first amount of UHF energy E_UHF1 is performed by means of a UHF receiver REC_UHF of the mobile beacon B_M. The first amount of UHF energy E_UHF1 is then compared with a threshold energy value E_threshold. The threshold energy value E_threshold is, for example, the energy value from which it is assumed that a zone of the environment is sufficiently supplied with UHF energy and does not require additional UHF energy supply to allow sufficient detection of the UWB radio tags present in this zone of the environment. In one example, the threshold energy value is a predetermined threshold energy value. The predetermined threshold energy value is, for example, configured by a user using the user interface connected to an electronic device comprising the mobile beacon B_M or paired with said mobile beacon B_M. The comparison between the first amount of UHF energy E_UHF1 and the threshold energy value E_threshold is, for example, carried out by means of a comparator and makes it possible to determine whether the first amount of UHF energy E_UHF1 is lower or higher than the threshold energy value E_threshold. Comparing the first amount of UHF energy E_UHF1 with the threshold energy value E_threshold makes it possible in particular to determine whether a zone is sufficiently supplied with UHF energy by the infrastructure or whether, on the contrary, this zone requires an additional UHF power supply to allow the tags present in said zone to transmit UWB frames.

[0170] In one embodiment, with reference to FIG. 6, the mobile beacon B_M is configured to transmit the first UHF signal S_UHF1 if the first amount of UHF energy E_UHF1 is less than the threshold energy value E_threshold and to reduce energy transmitted by the UHF transmitter EM_UHF in the event that the first amount of UHF energy E_UHF1 received is greater than the threshold energy value E_threshold. This configuration advantageously makes it possible to “map” the UHF energy of several zones and, a posteriori, either to supply UHF energy to a weakly supplied zone, or on the contrary, to reduce transmission of UHF signals by the mobile beacon B_M if the zone is already sufficiently supplied. In one example, transmission of the first UHF signal S_UHF1 advantageously results in the spontaneous transmission of UWB signals by tags present in an initially low-energized zone. Another advantage is to be able to detect change of state in the detection environment, for example a failure of a transmitter or a re-arrangement of elements in the environment resulting in an increase or decrease in the overall detected UHF energy. Another advantage is to be able to reduce overall power consumption of the system by reducing the UHF power transmitted by the different beacons in the zone if said zone is already sufficiently energized.

[0171] In one embodiment, the mobile beacon B_M is configured to transmit a signal comprising a UHF coverage piece of information. The UHF coverage piece of information may comprise, for example, a piece of information on the amount of UHF energy received by the mobile beacon B_M. The signal comprising the UHF coverage piece of information may be, for example, the second UWB signal S_UWB2 if the UHF coverage piece of information is sent to equipment comprising a UWB receiver, such as a fixed beacon or another mobile beacon. The signal comprising the UHF coverage piece of information may also be of a different nature, if the UHF coverage piece of information is sent to another piece of equipment, such as a piece of equipment in a data network NET. One advantage is to be able to collect information on the amount of UHF energy present in a zone of the environment, in order to be able to a posteriori modulate the UHF energy transmitted by the different beacons near the zone in which the mobile beacon B_M performs a UHF coverage diagnosis, according to the amount of UHF energy present in said zone.

Near Field Illumination

[0172] In one embodiment, with reference to FIG. 7, the method according to the invention comprises measuring a distance value V_dis between an object and the mobile beacon B_M by means of a distance sensor. The distance sensor may comprise, for example, an ultrasonic sensor, an inductive sensor, a magnetic sensor, an optical sensor or even a capacitive sensor. The distance sensor can be an infrared range finder, for example. However, the distance sensor used is not limited to the aforementioned examples and may comprise any type of sensor for evaluating a distance between said sensor and an object, or even a combination of different sensors for obtaining a more accurate value of the distance between the object and the mobile beacon B_M.

[0173] In one embodiment, the distance value V_dis measured by means of the sensor is compared with a predetermined threshold distance value V_threshold. Comparison can be done using a comparator COMP.

[0174] In one example, transmission of the first energizing UHF signal S_UHF1 is then modulated according to the result of the comparison between the distance value V_dis and the predetermined threshold distance value V_threshold. Modulating the first UHF signal S_UHF1 may, for example, comprise increasing power of said first UHF signal S_UHF1 delivered when the distance value V_dis is greater than the predetermined threshold distance value V_threshold. This advantageously makes it possible to adapt the signal when the UHF transmitter EM_UHF of the mobile beacon B_M is at a position away from a UWB tag, to ensure detection of said UHF signal S_UHF1. Modulating the first UHF signal S_UHF1 may also comprise reducing power of said first UHF signal S_UHF1 when the distance value V_dis is less than the predetermined threshold distance value. This advantageously makes it possible to reduce the overall energy consumption of the system by reducing power of the first UHF signal S_UHF1 transmitted when the UHF transmitter EM_UHF of the mobile beacon B_M is close to a UWB radio tag to be energized.

[0175] In one alternative, modulating the first UHF signal S_UHF1 comprises increasing power of said first UHF signal S_UHF1 when the distance value V_dis from the UHF transmitter to the object is less than the distance value threshold V_threshold. This advantageously makes it possible to optimize UHF energy supply of a UWB radio tag when the UHF transmitter of the mobile beacon B_M is close to said UWB radio tag to be energized. Another advantage is to confirm presence of a UWB radio tag on the object in proximity to the mobile beacon. Indeed, a UWB radio tag is configured to transmit at least one UWB signal in response to the power supply provided by a UHF signal.

[0176] In one alternative, modulating the first UHF signal S_UHF1 comprises reducing power of said first UHF signal S_UHF1 when the distance value V_dis from the UHF transmitter to the object is greater than the distance value threshold V_threshold. This advantageously allows the energy of the UHF power source to be saved when the UWB radio tags are too distant to be properly energized.

[0177] In one embodiment, receiving a UWB signal by the UWB receiver REC_UWB of the mobile beacon B_M causes power of the first UHF signal S_UHF1 to increase in response to said receiving the UWB signal. This increase in power can, for example, be implemented by a user via a user interface. In this case, the user interface comprises a control unit for modulating the UHF signal transmitted by the UHF transmitter EM_UHF of the mobile beacon and means for informing the user of the reception of a UWB signal by the mobile beacon B_M, for example, visual or audible alert means. One advantage is to ensure that the UWB signal received by the mobile beacon B_M comes from a UWB radio tag located in proximity to the UHF source.

[0178] In one embodiment, the first UWB signal S_UWB1 received by the mobile beacon B_M is associated with a duration time piece of information. The duration time piece of information comprises, for example, the duration during which the first UWB signal S_UWB1 transmitted by the first UWB tag ET₁ has been received by the mobile beacon B_M. The duration time piece of information may also comprise the first timestamping piece of data H₁ of the reception of said first signal UWB S_UWB1 by the mobile beacon B_M. The duration time piece of information can, for example, be stored in the memory MEM of the mobile beacon B_M. One advantage is to associate a reception duration with a UWB signal received by the mobile beacon B_M, for example to ensure that said received UWB signal actually comes from a UWB tag located in proximity to the mobile beacon.

[0179] According to one embodiment, the duration time piece of information associated with the first UWB signal S_UWB1 is sent to a piece of equipment of a data network NET by means of a non-wired link. The non-wired link may comprise WI-FI, 4G, 5G, or Bluetooth transmission means. This configuration is particularly advantageous when a same UWB signal is received by a plurality of mobile beacons. The duration time piece of information comprising the duration of reception of the first UWB signal makes it possible to determine which mobile beacon B_M is located in proximity to the UWB radio tag originating transmission of said first UWB signal S_UWB1.

[0180] In one alternative, the duration time piece of information associated with the first UWB signal S_UWB1 may be transmitted to a UWB receiver of a fixed beacon or another mobile beacon within the second UWB signal S_UWB2 transmitted by the UWB transmitter EM_UWB of the mobile beacon B_M.

[0181] According to one embodiment, the duration time piece of information is associated with the distance value V_dis from the UHF transmitter to the object. In this example, the first tag UWB ET₁ is affixed to the object from which the distance value V_dis is measured. The association can be made within the memory MEM of the mobile beacon or within a piece of equipment of a data network NET. This configuration is advantageous in the event that a same UWB signal is received by a plurality of mobile beacons. It is thereby possible to more precisely identify the mobile beacon B_M located in proximity to the radio tag UWB originating transmission of the first UWB signal S_UWB1 sensed by a plurality of mobile beacons B_M. Another advantage is to reduce uncertainty on the position of the UWB radio tag originating transmission of the first UWB signal S_UWB1.

[0182] In one embodiment, the first UWB signal S_UWB1 received by the mobile beacon B_M is associated with a context piece of information. The context piece of information also includes information on the context in which the mobile beacon B_M operates when it receives the UWB signals from an energized UWB tag. This context piece of information may notably comprise values associated with physical data related to the environment in which the mobile beacon B_M operates, or values associated with physical data related to the mobile beacon B_M itself. The context piece of information can, for example, comprise the distance value V_dis to an obstacle or even the distance value of the mobile beacon B_M to the ground, the first position piece of data POS₁, a movement piece of information of the mobile beacon B_M or even the duration time piece of information. The duration time piece of information comprises, for example, the duration during which the first UWB signal S_UWB1 transmitted by the first UWB tag ET₁ has been received by the mobile beacon B_M. The duration time piece of information may also comprise the first timestamping piece of data H₁ of the reception of said first signal UWB S_UWB1 by the mobile beacon B_M. In another case, the duration time piece of information comprises the time during which the environment has been energized by the embedded UHF transmitter EM_UHF by the mobile beacon B_M. According to another example, the context piece of information comprises a sound recording acquired by a sensor, or even an image or video sequence acquired by a camera positioned on the mobile beacon B_M.

[0183] In one embodiment, the context piece of information comprises information on the directionality of the UHF signal S_UHF1 transmitted by the UHF transmitter EM_UHF of the mobile beacon B_M. According to one example, the piece of information comprises a privileged UHF direction piece of information for the UHF signal S_UHF1.

[0184] In one embodiment, the context piece of information comprises information on the duration between switching on and switching off transmission of the first energizing signal S_UHF1. According to one case, the context piece of information also includes information on antennas of the mobile beacon B_M involved in the transmission of the energizing signal S_UHF1 and information on the orientation of said antennas in space.

[0185] In one embodiment, the duration piece of information comprises a piece of information on the duration of energization of a UWB tag by the first energizing signal S_UHF1 coupled to a piece of information on the power transmitted by the source S_UHF1.

[0186] According to one example, the context piece of information comprises a piece of information on the presence of other mobile beacon BMS in the detection environment. According to another example, the context piece of information comprises values measured by different sensors installed on the mobile beacon B_M such as position sensors, motion sensors, temperature sensors or even pressure sensors. The context piece of information may be processed by processing means to determine an identification piece of data of at least one mobile beacon having transmitted a first UHF energizing signal S_UHF1 originating the transmission of a first UWB signal S_UWB1 by a first UWB radio tag ET₁ and received by the mobile beacon B_M. One advantage is to be able to precisely identify a mobile beacon originating the transmission of an energizing UHF signal having energized a UWB radio tag, according to different physical parameters.

Mobile Beacon

[0187] According to another aspect, the invention relates to a mobile beacon B_M configured to implement the method of the invention according to any one of the previously described embodiments.

[0188] In one embodiment, the mobile beacon B_M comprises means for storing an amount of electric energy. The means of storing an amount of electric energy in particular enable the UHF transmitter EM_UHF of the mobile beacon, or the various sensors installed on the mobile beacon B_M to be supplied with electric energy. The means of storing an amount of electric energy may, for example, comprise a battery. The battery can, for example, be charged at the mains. The means of storing electric energy may comprise any battery technology among lithium-ion, Ni-Cad, Ni-Mh or Pb/Sla technologies. However, this embodiment of the invention is not limited to the aforementioned battery technologies. In one embodiment, the mobile beacon may comprise an association of a plurality of battery technologies or even several batteries of similar technologies.

[0189] In one embodiment, the mobile beacon B_M comprises a photovoltaic source of electric energy supply. The photovoltaic source of electric energy supply comprises, for example, a solar panel or a plurality of solar panels.

[0190] The mobile beacon B_M may comprise an indicator of the charge level of the means for storing electric energy. The indicator may be a visual indicator such as a light indicator. According to one alternative, the indicator may be an audible indicator such as an alarm. The mobile beacon B_M may also comprise a combination of visual and/or audible indicators. The indicator can be configured to activate when the charge level of the electric energy storage means falls below a predetermined charge threshold. This configuration is particularly advantageous in the event that the electric energy storage means require a mains supply, to warn a user of the need to recharge said electric energy storage means. Another advantage is to be able to warn a user of a risk of malfunction of the mobile beacon B_M in the event of excessive discharge of said electric energy storage means.

[0191] In one embodiment, the mobile beacon B_M comprises embedded sensors. Embedded sensors can include pressure sensors, distance sensors, shock sensors, vibration sensors or temperature sensors. In general, the mobile beacon B_M may comprise any type of sensor for obtaining information on physical parameters of the environment in which said mobile beacon B_M operates, or even any type of sensor for measuring values of physical parameters derived from the interaction between said mobile beacon B_M and its environment. In one example, the different sensors are supplied by a battery of the mobile beacon B_M.

[0192] According to one embodiment in which the mobile beacon B_M comprises a plurality of sensors, the data measured by the different sensors are stored within the memory MEM of the mobile beacon B_M. According to one exemplary embodiment, the measured data are timestamped and stored in the memory MEM of the mobile beacon B_M are then sent to a piece of equipment of a data network NET. This is particularly advantageous for collecting information about the environment in which the mobile beacon B_M operates and about possible interactions between said mobile beacon B_M and its enviornment.

[0193] In one embodiment, the mobile beacon B_M comprises control means. The control means are configured to control transmission of the first UHF signal S_UHF1 transmitted by the UHF transmitter EM_UHF of the mobile beacon B_M. The control means can be controlled by a user. Control by a user is, for example, implemented by means of a user interface of an electronic device comprising the mobile beacon B_M or paired with said mobile beacon B_M. The control means can make it possible to modulate the first UHF signal S_UHF1 delivered by at least one transmission antenna of the mobile beacon B_M. The control means may also allow shutdown of at least one transmission antenna of the mobile beacon B_M. The control means may be autonomous. By “autonomous”, it is meant that the control means can be configured upstream by a user to automatically control modulation of a UHF signal transmitted by a transmission antenna or to control shutdown of a transmission antenna. This automatic control of transmission antennas may depend on the reception and processing of a piece of information from a sensor such as a motion sensor, a position sensor or any other sensor embedded by the mobile beacon B_M.

[0194] According to one embodiment, the mobile beacon may comprise one or a plurality of detection indicators. Detection indicators may be visual and/or audible indicators. According to one example, the detection indicators allow a user to be informed of the detection of a UWB signal by the mobile beacon B_M. Detection indicators can be, for example, indicator lights or alarms. The indicators may also be integrated into a user interface including, for example, a screen and sound transmission means. In this case, the visual indicators may comprise a detection message appearing on the user interface screen and the audible indicators the issuance of an alert sound by the sound transmission means. One advantage is to warn a user of the presence of a UWB transmitter such as a radio tag in the zone where the mobile beacon B_M is located. According to another example, receiving a UHF signal by a UHF receiver of the mobile beacon B_M causes the visual and/or audible indicators to be activated. An advantage is to warn a user of the presence of another UHF source in the zone in which the mobile beacon B_M is located.

[0195] In one embodiment, the mobile beacon B_M is configured to exchange data with at least one other mobile beacon. Data can be exchanged by transmitting a second UWB signal S_UWB2 by the mobile beacon B_M and receiving said second UWB signal S_UWB2 by another mobile beacon. The second UWB₂ signal may comprise some or all of the data stored in the internal memory of the mobile beacon B_M. One advantage is to allow data exchange between multiple mobile beacons when network coverage does not allow connection to a piece of equipment on the data network NET, for example when there is no WI-FI, 3G, 4G or 5G coverage.

[0196] According to one embodiment, the mobile beacon B_M comprises a memory. The memory allows the mobile beacon B_M to store decoded information of received signals, such as identification data of a piece of equipment having transmitted a signal received by the mobile beacon B_M, for example the first piece of data D₁, position data, for example the first position piece of data POS₁, timestamping data (such as timestamping of transmission and reception of UWB signals), data measured by sensors embedded by the mobile beacon B_M, or even the context piece of information.

[0197] The information is, for example, stored in the memory of the mobile beacon B_M as long as it is not connected to a data network, and is, for example, transmitted to a remote equipment by means of a wireless link as soon as the connection is reestablished. This transmitted information can be subsequently operated on a remote equipment or on a data server that has received the information transmitted by the mobile beacon B_M, for example by implementing calculations by means of a calculator to reconstruct a position or a path of the mobile beacon B_M over a given time interval.

Mobile Cart Embedding a Mobile Beacon

[0198] According to another aspect, with reference to FIG. 8, the invention relates to a mobile cart C_M embedding the mobile beacon B_M according to the invention and more generally any rolling object capable of moving and including a mobile beacon.

[0199] The mobile beacon B_M can be made integral with the mobile cart C_M by mechanical connection means. The mechanical connection means may comprise attachment elements such as screws, nuts, bolts where any other attachment element likely to make the mobile beacon B_M integral with said mobile cart C_M. In one alternative, the mobile cart comprises at least one rail and the mobile beacon comprises means of cooperation with said at least one rail, the mechanical cooperation of said at least one rail of the mobile cart C_M with the means of cooperation of the mobile beacon B_M resulting in a mechanical assembly securing the mobile beacon B_M to said mobile cart C_M. However, the elements included in the mechanical connection means are not limited to the aforementioned examples, and any mechanical element for securing the mobile beacon B_M to the mobile cart C_M may be included in the mechanical connection means. Advantageously, the risks of deteriorating the mobile beacon B_M when moving the mobile cart C_M are thus reduced.

[0200] In one embodiment, the mobile cart C_M embedding the mobile beacon B_M is a lifting and handling apparatus, such as a forklift. According to another example, the mobile cart C_M is a hand-operated pallet truck. In this example, the lifting and handling device includes a lifting system. The lifting system may comprise a plurality of elements such as a pulley, mast, hydraulic system, and forks. The lifting and handling apparatus may comprise an engine or motor compartment containing a motor such as an electric motor or an engine such as a heat engine. The lifting and handling apparatus may comprise a cabin intended for receiving a user of said lifting and handling apparatus. The cabin may include a steering wheel, seat, and means for controlling the lifting system. In this exemplary embodiment, the mobile beacon B_M made integral with the lifting and handling apparatus advantageously enables UWB tags affixed to objects such as parcels moved by said lifting and handling apparatus to be energized.

[0201] The mobile beacon B_M can be made integral with the lifting system of the mobile cart C_M by the mechanical connection means. This advantageously allows moving the mobile beacon B_M by moving the lifting system. This configuration is particularly advantageous when the mobile beacon B_M comprises a UHF transmitter and a UWB tag is affixed to a parcel located at height. The movement of the lifting system then allows the UHF source to be brought closer to the UWB tag to be supplied, to cause transmission of a UWB signal by said UWB tag. This configuration is particularly advantageous in the case of loading an object at height onto the moving part of the forklift. Indeed, the fact that the mobile beacon B_M is made integral with the mobile part of the cart allows detecting the object that the user is loading and therefore it is not necessary to wait until the mobile part has returned to its initial position to detect the loaded object.

[0202] According to one embodiment, the mobile beacon B_M and/or the mobile cart comprises a distance sensor. The distance sensor is configured to calculate a distance between the ground and the moving part of said mobile cart C_M. The distance sensor can be either an ultrasonic sensor or a laser range finder. However, the type of sensor used is not limited to the above examples and can include any type of distance sensor or a combination of several distance sensors. One advantage is to determine how far from the ground the mobile part of the forklift is when loading or unloading an object containing a UWB tag.

[0203] In one embodiment, the mobile cart C_M comprises a battery. The battery can be a battery for supplying both the mobile cart C_M and the mobile beacon B_M with electric energy. According to one alternative, the battery is only used to supply the mobile cart with electric energy. The mobile cart may also comprise audible and/or visual indicators. The audible and/or visual indicators are intended to warn a user of exceeding a predetermined charge level of said battery. This is particularly advantageous to warn a user of the need to recharge said battery to avoid system malfunction.

[0204] In one embodiment in which the battery supplies both the mobile cart C_M and the mobile beacon B_M, exceeding the predetermined charge level of the battery causes the power supply of the mobile beacon B_M to be interrupted by said battery. This advantageously makes it possible to save the remaining electric energy in the battery, for example to allow a user to use the remaining energy to approach a charging point such as a mains socket.

[0205] In one embodiment, the mobile cart C_M embedding the mobile beacon B_M may comprise a charging cradle. The charging cradle may comprise at least one electrical connector. The at least one electrical connector is configured to electrically connect to the battery of the mobile beacon B_M. Electrical connection between the charging cradle and the mobile beacon can be made, for example, via a plug and a socket. According to one embodiment, the charging cradle may advantageously be positioned at the lower part of the mobile cart C_M, at the lifting system. In this example, the connector of the cradle is configured to connect to the battery of the mobile beacon B_M via the at least one electrical connector when the mobile cart lifting system is in the lowered position and the mobile beacon is made integral with said lifting system of the mobile cart C_M. One advantage is that the battery of the mobile beacon B_M can be recharged when the lifting system of the mobile cart is not operated for loading or unloading an object. Another advantage is that there is no need for electrical cables connected to the battery of the mobile beacon B_M. In one alternative, the charging cradle includes an induction charger. The induction charger comprises, for example, a planar surface comprising a copper coil. However, any type of technology enabling the mobile beacon B_M to be charged by induction is likely to be implemented within the scope of the invention. According to one example, the mobile beacon B_M comprises a receiver compatible with the induction charger.

[0206] According to one embodiment, the mobile beacon B_M and/or the mobile cart C_M comprises light emitting means. The light emitting means may, for example, comprise a lamp, a headlight or any other electrically powered element configured to emit a light signal. The light emitting means can, for example, be powered by the battery of the mobile cart C_M or the mobile beacon B_M. One advantage is to be able to light the environment when moving the mobile cart C_M embedding the mobile beacon B_M or when loading an object by said mobile cart C_M.

[0207] In one embodiment, the mobile beacon B_M and/or the mobile cart C_M comprise video recording means. The video recording means may, for example, comprise a camera. The video recording means can for example be powered by the battery of the mobile beacon B_M or the mobile cart C_M. One advantage is to be able to associate an image or video sequence with timestamping of the reception of a UWB signal by the mobile beacon B_M. The images and/or video sequences acquired may, for example, be stored in the memory MEM of the mobile beacon B_M. This advantageously makes it possible to improve identification of the tags originating the transmission of the UWB signals received by the mobile beacon B_M, by obtaining a picture of said tags.

[0208] According to one embodiment, the mobile cart comprises a screen. For example, the screen is located in a user's cabin. In one embodiment, the screen is connected to the video recording means. One advantage is to allow a user to live track acquisition of video sequences by the video recording means. Another advantage is to be able to detect live a possible failure of said video recording means or even an anomaly when loading an object on the mobile cart C_M. In one embodiment, the mobile cart C_M embedding the mobile beacon B_M comprises a user interface. The user interface comprises, for example, a digital tablet comprising an internal memory. In one embodiment, the digital tablet comprises non-wired connection means for connecting to a piece of equipment of the data network. The non-wired connection means comprise, for example, a WI-FI, 3G, 4G, 5G or Bluetooth link. The digital tablet is connected to the mobile beacon via a wired or non-wired link. One advantage is to allow the mobile beacon to transmit part of the information contained in its memory MEM to the tablet. Another advantage is to allow a user to view the information contained in the memory of the mobile beacon B_M directly on the digital tablet. Data contained in the internal memory of the digital tablet can be sent to a piece of equipment of the data network NET via non-wired connection means. In one embodiment, the link between the user interface and the piece of equipment of the data network NET is bidirectional. One advantage is to be able to retrieve information recently stored on the piece of equipment of the data network NET by at least one other connected piece of equipment, for example another mobile beacon B_M.

[0209] According to one embodiment, the screen of the mobile cart C_M is configured to display contextual information. These are, for example, data measured by sensors, such as temperature data, data of the distance separating the mobile beacon B_M or the mobile cart C_M from an object in the environment. The contextual information displayed by the screen may also comprise information identifying a user. For example, the screen may comprise an interface through which a user identifies by means of a password. This information can then be stored in memory and possibly transmitted to third-party piece of equipment or a data network via a wireless link. Contextual information can also include a piece of data relating to the time the mobile cart C_M is occupied by a user, or a piece of information on the equipment state (sensor failure detected, battery charge rate).

[0210] The contextual information may also comprise the contextual piece of information associated with the first signal S_UWB1. Contextual information may also comprise information identifying an object transported by the mobile cart B_M, or identifying a recipient of the object transported on the mobile cart B_M. For example, this includes information on the nature of an object transported within a box on which a radio tag UWB is affixed, or an identification piece of information of a customer for whom the object transported by the mobile cart C_M is intended. In one example, the user interface displays several contextual pieces of information on the screen and displays an interface through which the user can confirm whether or not the information displayed is compliant. Contextual information and compliance validation can then be transmitted via a wireless link and by means of a communication interface, via a signal encoding these data. All this information can also be stored within a memory for transmission subsequently, or even for reading by another user.

[0211] According to one embodiment, the mobile beacon is associated with several pieces of equipment comprising screens. It is for example a fixed piece of equipment in the mobile cart, and a mobile piece of equipment such as a mobile tablet or smartwatch. For example, both screens are configured to display contextual information. Thus, advantageously, if the screen in the cabin displays a piece of information that requires verification, such as a loading problem, the user can exit the mobile cart and check whether the information are compliant or not by having access to display of the contextual information when they are outside the mobile cart. A piece of equipment comprising a display and associated with the mobile beacon may also be configured to transmit radio messages, such as UWB signals, for example to allow locating a user, or to allow correlation of the position of the user with that of the mobile beacon B_M or the mobile cart C_M. According to one example, a piece of equipment comprising a screen is configured to implement communication and/or location means, for example via wifi, Bluetooth, 4G or GNSS, to detect and associate with a mobile beacon B_M or a mobile cart C_M present in the proximity thereof. According to another example, a piece of equipment comprising a screen and associated with the mobile beacon B_M or the mobile cart C_M is configured to issue an alert when it detects a connection error with the mobile beacon B_M or with the mobile cart C_M. For example, this may be a case where the piece of equipment is paired with another mobile beacon B_M or another mobile cart C_M than the one it was configured to associate with. The alert can include an audible alert, an error message display, or even vibration.

[0212] According to one embodiment, the mobile beacon B_M and/or the mobile cart C_M is configured to associate with one or more pieces of equipment comprising a screen comprising the user interface.

[0213] According to one embodiment, the mobile beacon B_M and/or the mobile cart C_M is configured to associate with a piece of equipment comprising a screen and comprising sensors. The sensors include, for example, motion sensors, a compass or even a camera. The piece of equipment including a screen may also comprise an integrated location system. In this case, the contextual information includes, for example, both data received from sensors positioned on the mobile beacon B_M and/or on the mobile cart C_M and data received from sensors positioned on the piece of equipment comprising a screen and comprising sensors.

[0214] In one embodiment, the mobile beacon B_M embedded by the mobile cart C_M comprises shock detection means. The shock detection means may for example comprise a shock sensor or a vibration sensor. The shock detection means are configured to detect vibration or shock when moving the mobile cart C_M or the mobile part of said mobile cart C_M. In one embodiment, detection of a vibration or a shock causes a detection signal to be transmitted from the shock detection means to the memory MEM of the mobile beacon. The detection signal includes a piece of information about a shock or vibration detected by the shock detection means. Transmission of the detection signal can be “automated”. By “automated”, it is meant that transmission of the detection signal can be carried out automatically to the memory of the mobile beacon B_M, for example when a certain shock or vibration threshold is reached.

[0215] In one embodiment, the detection signal is associated with the first tag piece of data ET₁. One advantage is to detect whether an object on which a UWB tag is affixed has received a shock upon loading, unloading or transporting said object. In one alternative, detection of a shock or vibration by the shock detection means results in the activation of a visual and/or audible indicator. For example, the indicator can be triggered when the shock or vibration measured exceeds a predetermined threshold value. In one example, the predetermined threshold value is set by a user via the user interface. One advantage is to produce a piece of information and transmit it directly to a user if the mobile cart C_M and/or the mobile beacon B_M embedded has been potentially damaged by the shock or vibrations. The user may also advantageously be informed of a risk of loss of calibration of the mobile beacon B_M as a result of the shock experienced.

Mobile Beacon Embedded by a User

[0216] According to another aspect illustrated in FIG. 9, the invention relates to an element embedded by a user including a mobile beacon B_M according to the invention. By “element embedded by a user”, it is meant that the position of the “embedded” element follows the position of the user embedding said element when said user moves. Thus, according to various examples, the embedded element comprises a strapped element such as a harness, an element comprising shoulder straps such as a backpack, an element including a handle such as a suitcase, a handheld scanner, or even an element strapped onto a body limb of a user such as their arm. More generally, any type of element that can be embedded, moved or transported by a user is likely to be implemented within the scope of the invention. In one alternative, the mobile beacon B_M is embedded by a user in a garment such as a vest comprising compartments for accommodating said mobile beacon B_M.

[0217] According to one embodiment, the mobile beacon B_M is embedded by a user by means for attaching said mobile beacon B_M to the user's body or garment. The attachment means may, for example, comprise a hook-and-loop fastener, or any other element allowing said mobile beacon B_M to be secured to a user's body part or garment.

[0218] In one embodiment, the embedded element comprises at least one sensor. According to various examples, the sensor comprises a pressure sensor or even a motion sensor. More generally, any type of sensor enabling a physical parameter to be measured in connection with the user, with the environment in which the user operates or even in connection with interactions of said user with their environment is likely to be implemented within the scope of the invention. One advantage is to be able to determine a physical piece of information to define the context, for example an odometric type piece of information to deduce that the mobile beacon B_M is in motion therefrom.

[0219] In one embodiment, the embedded element comprises at least one reading device. In one case, the reading device is configured to decode at least one piece of information from another device. According to one example, the reading device is configured to scan a piece of information stored in a quick response code, or even “QR code”. According to another example, the reading device comprises a radio frequency identification, or “RFID” reader.

[0220] According to one embodiment, the reading device is offset to a part of a user's body. According to one example, the reading device is offset to a user's lower limbs. Depending on different cases, the reading device comprises wired or non-wired connection means. One advantage is that be able to read information previously stored in the environment. Another advantage is to be able to locate a mobile beacon B_M more precisely.

[0221] According to another aspect, the invention relates to a system comprising a mobile beacon and at least one UWB radio tag.

[0222] According to one embodiment, the system comprises a plurality of UWB tags, the mobile beacon B_M according to the invention, and the location system L_GEO. The elements of the system may interact with each other to implement any of the embodiments of the method according to the invention.

[0223] In one embodiment, the system also comprises a mobile cart C_M embedding the mobile beacon B_M or any rolling object likely to move and including a mobile beacon. According to another example, the system comprises an element embedded by a user and the mobile beacon B_M according to the invention.

[0224] In all cases, the mobile beacon B_M included in the system is configured to implement any of the embodiments of the method according to the invention.