All-terrain robotic omni-directional drive assembly

[0001] The present invention relates generally to a robotic omni-directional drive assembly and more particularly to an all-terrain omni-wheel drive assembly with versatile operating environment capabilities.

[0002] Robotic drive assemblies are often sensitive to the differing terrains on which they are required to traverse. As a result, drive assemblies are often designed to accommodate only narrow environmental scenarios. The resultant robotic drive assemblies are, therefore, commonly designed to be narrowly configured for highly specific operating environments. Operation outside such narrow parameters can result in drive failure or incapacitation of the robotic assembly.

[0003] A common approach to all-terrain operation has been through the development of highly complex mechanical drive assemblies suitable for multi-environmental operation. However, the complexity of such drive assemblies exposes these drives to mechanical failure or undesirable maintenance requirements. In addition, complexity also drives production costs and assembly weight. This can serve to limit the suitable applications for which the drive assembly may be utilized.

[0004] A robotic drive assembly with reduced complexity and the ability to cope with a vast diversity of operation environments would reduce manufacturing costs and provide an increased range of application and operation. In addition, maintenance costs and schedules could be significantly reduced. These benefits would serve a host of applications ranging from entertainment to aerospace.

[0005] In accordance with the objects of the present invention a main ellipsoidal drive element is provided including a buoyant internal chamber. The main ellipsoidal drive element defines a main ellipsoid axis, a minor ellipsoid plane, a first ellipsoid end portion, a second ellipsoid end portion, and an outer ellipsoid surface. A drive engagement element is mounted to the first ellipsoid end portion and selectively transfers rotational drive to the main ellipsoidal drive element around the main ellipsoid axis. A plurality of roller elements are mounted around a minor ellipsoid periphery of the main ellipsoidal element. Each of the roller elements are orientated to provide friction reduced rolling in a main ellipsoid axis direction and traction perpendicular to the main ellipsoid axis direction.

[0006] Other objects and features of the present invention will become apparent when viewed in light of the detailed description and preferred embodiment when taken in conjunction with the attached drawings and claims.

[0018] Referring now to FIGS. 1-3, which are illustrations of an all-terrain omni-directional drive assembly 10 in accordance with the present invention. The all-terrain omni-directional drive assembly 10 is intended for a variety of applications. One contemplated embodiment is for utilization in robotic drive assemblies. The present drive assembly provides a versatile drive platform capable of traversing obstacles in addition to travel on both solid ground and water.

[0019] The all-terrain omni-directional drive assembly 10 includes a robotic drive platform 12 including an upper platform surface 14 and a side platform periphery 16. A variety of applications and additional hardware may be mounted to the robotic platform 12 in order to accommodate a broad range of utilizations. FIG. 8 illustrates one embodiment contemplating usage as an entertainment robotic assembly. Although a humanoid shaped robot is depicted, it should be understood that a variety of robot assemblies 17 may be mounted to the robotic drive platform 12. These robotic assemblies 17 may include complex logic and mechanics for a variety of advanced functions and may be logically integrated into the robotic drive platform 12.

[0020] The robotic drive platform 12 further includes a plurality of omni-wheel drive assemblies 18 mounted to the side platform periphery 16. Although any number may be utilized, at least one embodiment contemplates the use of three drive assemblies 18 mounted at a 120 degree spacing interval. In this fashion, two of the drive assemblies 18 may be selectively activated to produce forward or rearward movement while the third is dragged along with reduced friction as will be described below. The two activated drive assemblies are rotated toward each other to accomplish forward motion and away from each other to accomplish rearward motion. Rotation of the drive platform 12 may be accomplished by way of activating all three-drive assemblies 18 in the same direction. Although a variety of mounting configurations are contemplated, in one embodiment it is contemplated that the omni-wheel drive assemblies 18 are mounted to the platform periphery 16 at an approximate 72 degree angle (FIG. 6) to allow the omni-wheel drive assemblies 18 to engage terrain at an optimal angle.

[0021] Although rotation of the omni-wheel drive assemblies 18 may be accomplished in a variety of fashions, one embodiment contemplates the use of individual drive motors 20 associated with each drive assembly 18 (see FIG. 4). A drive transfer chamber 22 such as a gear chamber is mounted in communication with the drive motor 20 to transfer rotational drive to a drive engagement element 24. Although a variety of drive engagement elements 24 are contemplated, one embodiment contemplates the use of a drive wheel element 26 and an engagement pin 28 (see FIGS. 4 and 7). In light of the present specification, a wide variety of motorized configurations would be apparent.

[0022] The drive is transferred to a main ellipsoidal drive element 30, which forms the central element in the omni-wheel drive assembly 18 (see FIG. 4). The main ellipsoidal drive element 30 is responsible for converting the rotational drive provided by the drive motor 20 into actual forward/rearward movement of the robotic drive platform 12. An important aspect of the present invention is the ellipsoidal nature of the main ellipsoidal drive element 30. It should be understood that the term ellipsoidal need not be a pure geometric object but is intended to include a range of shapes including generally football-shaped forms and egg-shaped forms. Nevertheless, the general form may be defined as ellipsoidal. The main ellipsoidal drive element 30 therefore has a main ellipsoid axis 32 corresponding to the major axis of an ellipse. The main ellipsoid drive element 30 further includes a minor ellipsoid plane 34 corresponding to the minor axis of an ellipse. Where the minor ellipsoid plane 34 intersects the outer ellipsoid surface 36, a minor ellipsoid periphery 38 is generally defined. The main ellipsoidal drive element 30 further is defined by a first ellipsoid end portion 40 and a second ellipsoid end portion 42 corresponding to opposing ends of an ellipsoid along the main ellipsoid axis 32. The ellipsoidal configuration of the main drive element 30 allows it to easily be dragged over obstacles without getting hung up. The main ellipsoidal drive element 30 preferably includes a buoyant internal chamber 35 to allow transportation over fluid surfaces. Although this may be accomplished by forming the drive element 30 as a hollow shell, other buoyancy modifications are also contemplated.

[0023] Rotational drive is transferred about the main ellipsoid axis 32. As described above, every drive element 30 must be capable of producing rotational drive, but must additionally at times be dragged during non-operation. Therefore each drive element 30 must preferably have traction when rotated about the main ellipsoid axis 32 and relatively low frictional resistance when dragged in a main ellipsoid axis direction 44. The present invention accomplishes this through the use of a plurality of rollers 46 such as floating wheels. These rollers 46 are orientated parallel to the main ellipsoid axis 32 such that they provide traction when the main ellipsoid drive element 30 is rotated about the main ellipsoid axis 32 and reduced friction rolling when dragged in the main ellipsoid axis direction 44. Each of the rollers 46 is preferably mounted within the main ellipsoid drive element 30 such that only a portion of each roller 46 protrudes from the outer ellipsoid surface 36. In one embodiment, it is contemplated that each roller is mounted within a watertight well 48 so as to preserve the buoyancy of the main ellipsoid drive element 30. It should be understood, that while floating wheels have been described and illustrated, it is contemplated that the rollers 46 may additionally include a variety of reduced friction components including but not limited to cylindrical and spherical bearings.

[0024] A secondary aspect of the present invention is its ability to function on water or other fluids in addition or in place of terrestrial navigation. The buoyant internal chamber 35 can be utilized to provide the necessary floatation for marine navigation. The present invention, however, further contemplates the use of a plurality of fin elements 50 mounted on or formed on the outer ellipsoid surface 36 (see FIGS. 7a-7d). The fin elements 50 are preferably orientated parallel to the main ellipsoid axis 32 so as to provide paddle drive when the main ellipsoid drive element 34 is rotated. In sand and snow environments, the fin elements 50 additionally provide paddle drive. When the fin elements 50 are utilized in conjunction with the rollers 46 the present assembly 10 may traverse back and forth between land and sea. Although the combination of rollers 46 and fins 50 is preferred, it should be understood that the present invention may utilize either separately as well. The fin elements 50 may include a first fin group 52 positioned between each of the rollers 46 and having a fin height 54 preferably equal to or less than the roller protrusion height 56. In at least one embodiment, each of the first fin group 52 extends over a majority of the main ellipsoid axis 32. The present invention may further include a second fin group 58 (or utilized in lieu of the first group 52) positioned coincident with each of the rollers 46. For this group of fins 58, it is contemplated that each fin 50 is comprised of a first fin portion 60 running from the first ellipsoid end portion 40 to a roller 46 and a second fin portion 62 running from the roller 46 towards the second ellipsoid end portion 42.

[0025] In an additional embodiment illustrated in FIG. 7d, it is contemplated that each fin element 50 includes a solid fin portion 64 and a brush portion 66. The solid fin portion includes a first solid end 68 in contact with the outer ellipsoid surface 36 and a second solid end 70 extending away there from. The brush portion 66 is positioned on the second solid end 70. The brush portion 66 provides reduced friction drag while assisting in both mechanical drive on terrestrial surfaces and paddle drive on marine surfaces. It is even contemplated that the entire fin element 50 may be formed from a brush portion 66. A wide variety of brush depths 72 are contemplated including, but not limited to, eighth inch depths to two inch depths. Brush density is contemplated to be similar to a toothbrush, although a variety of brush densities may be utilized based on application criteria. The use of brush portions 66 in addition may allow for drive over ice surfaces wherein roller elements 46 alone may prove insufficient.

[0026] While the invention has been described in connection with one or more embodiments, it is to be understood that the specific mechanisms and techniques which have been described are merely illustrative of the principles of the invention, numerous modifications may be made to the methods and apparatus described without departing from the spirit and scope of the invention as defined by the appended claims.