Wheel structure and mobile body

Abstract

[Problem] To further the ability to traverse steps. [Solution] A wheel structure comprising: a rotary frame that is rotatable around a first rotational axis and extends in the axial direction of the first rotational axis; three or more wheel units respectively provided on substantially the same circumference of a side surface of the rotary frame, each wheel unit having a ground contact surface, which constitutes a part of a spherical surface of a virtual spherical body, and being rotatable around a second rotational axis orthogonal to the first rotational axis; and at least one or more projection parts that are provided so as to project from a side surface of the rotary frame extending from at least one side of the wheel unit, and that extend in the axial direction of the first rotational axis.

Description

Wheel structure and vehicle

[0001] The present disclosure relates to a wheel structure and a moving body.

[0002] For example, an omni-wheel or Mecanum wheel is known as an omnidirectional wheel that can rotate in all directions. Also, as disclosed in Patent Document 1 below, an omni-ball is known as a spherical omnidirectional wheel that has high step-crossing ability.

[0003] Japanese Patent Application Laid-Open No. 2007-210576

[0004] However, with the Omniball disclosed in Patent Document 1, the step-traversing ability depends on the radius of the spherical wheels. Therefore, with the technology disclosed in Patent Document 1, it was difficult to further improve step-traversing ability without increasing the size of the wheels.

[0005] Therefore, the present disclosure proposes a new and improved wheel structure and a moving body that can further enhance the ability to traverse steps.

[0006] According to the present disclosure, there is provided a wheel structure comprising: a rotating frame rotatable around a first rotation axis and extending in the axial direction of the first rotation axis; three or more wheel units each arranged on approximately the same circumference on a side of the rotating frame, each having a contact surface that constitutes a part of the spherical surface of a virtual sphere, and rotatable around a second rotation axis perpendicular to the first rotation axis; and at least one or more protrusions protruding from a side of the rotating frame extending from at least one side of the wheel unit and extending in the axial direction of the first rotation axis.

[0007] Furthermore, according to the present disclosure, there is provided a moving body having at least three or more wheel structures, each of which is rotatable around a first rotation axis, a rotating frame extending in the axial direction of the first rotation axis, three or more wheel units each provided on approximately the same circumference on the side of the rotating frame, each having a contact surface that constitutes a part of the spherical surface of a virtual sphere, and rotatable around a second rotation axis perpendicular to the first rotation axis, and at least one or more protrusions provided protruding from the side of the rotating frame extending from at least one side of the wheel unit, and extending in the axial direction of the first rotation axis.

[0008] 1 is a perspective view showing the overall configuration of a moving body equipped with an omnidirectional wheel according to an embodiment of the present disclosure; FIG. 2 is a perspective view of the omnidirectional wheel; FIG. 3 is a perspective view of the omnidirectional wheel with one of the spherical annular wheels removed; FIG. 4 is a perspective view of the first frame, the second frame, the spherical annular wheel, the auxiliary wheel, and the support member; FIG. 5 is a cross-sectional view of the omnidirectional wheel; FIG. 6 is a side view of the omnidirectional wheel as viewed in a plane from the axial direction of the first rotation axis; FIG. 7 is an explanatory diagram explaining the shape conditions of the omnidirectional wheel; FIG. 8 is a plan view of the omnidirectional wheel as viewed from above the ground; FIG. 9 is a perspective view showing the movement of the omnidirectional wheel when traversing a step; FIG. 10 is a perspective view showing the movement of the omnidirectional wheel when traversing a step by moving in the axial direction of the first rotation axis of the rotating frame; FIG. 11 is a perspective view of the omnidirectional wheel according to a first modified example; FIG. 12 is a perspective view of the omnidirectional wheel according to the first modified example; FIG. 13 is a perspective view of the omnidirectional wheel according to the second modified example; FIG. 14 is a partial perspective view of the omnidirectional wheel according to the third modified example; FIG. 15 is a side view of the omnidirectional wheel according to the fourth modified example as viewed in a plane from the axial direction of the first rotation axis; 32. A side view of an omnidirectional wheel according to a sixth modified example. A side view of an omnidirectional wheel according to a sixth modified example. A side view of an omnidirectional wheel according to a sixth modified example. A side view of an omnidirectional wheel according to a sixth modified example. A side view of an omnidirectional wheel according to a sixth modified example. A partial side view of an omnidirectional wheel according to a seventh modified example. A partial perspective view of an omnidirectional wheel according to an eighth modified example. A perspective view of an omnidirectional wheel according to a ninth modified example. A side view showing an example of an omnidirectional wheel according to a tenth modified example. A perspective view showing another example of the omnidirectional wheel according to the tenth modified example. A perspective view of an omnidirectional wheel according to an eleventh modified example. A perspective view of an omnidirectional wheel according to a twelfth modified example. A perspective view of an omnidirectional wheel according to a thirteenth modified example. A cross-sectional view showing a cross section of a wheel unit of an omnidirectional wheel according to a fourteenth modified example. A perspective view partially showing an omnidirectional wheel according to a fifteenth modified example. A bottom view schematically showing the bottom of a moving body to which an omnidirectional wheel according to this embodiment is applied. A top view showing an example of how the moving body shown in FIG. 32 climbs steps. A top view showing an example of how the moving body shown in FIG. 32 climbs steps. 33 is a top view showing another example of how the moving body shown in FIG. 32 climbs up a step. FIG. 34 is a top view showing another example of how the moving body shown in FIG.FIG. 33 is a top view showing another example of how the moving body shown in FIG. 32 climbs up a step. FIG. 34 is a perspective view showing the appearance of a moving body to which the omni-directional wheel according to the present embodiment is applied. FIG. 35 is a perspective view showing an example of an omni-wheel. FIG. 36 is a perspective view showing an example of an omni-wheel. FIG. 37 is a perspective view showing an example of an omni-wheel. FIG. 38 is a front view showing the configuration of an omni-wheel to which the technology according to the present disclosure is applied. FIG. 39 is a side view showing variations of protrusions ... top view showing an example of the configuration of a moving body equipped with an omni-wheel.

[0009] Preferred embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings. In this specification and drawings, components having substantially the same functional configurations are designated by the same reference numerals, and redundant description will be omitted.

[0010] The description will be given in the following order: 1. Overall configuration of the moving body 2. Wheel structure 2.1. Configuration example 2.2. Operation example 3. Modification example 4. Application example 5. Supplementary notes

[0011] 1. Overall Configuration of Mobile Object> The overall configuration of a mobile object 1 equipped with omnidirectional wheels 12 according to an embodiment of the present disclosure will be described with reference to Fig. 1. Fig. 1 is a perspective view showing the overall configuration of a mobile object 1 equipped with omnidirectional wheels 12 according to this embodiment.

[0012] As shown in FIG. 1 , the moving body 1 includes a main body 11 and four omnidirectional wheels 12 .

[0013] The main body 11 is a main part of the mobile object 1. For example, the main body 11 includes a flat main body frame and four mounting frames that protrude radially from the main body frame. Omnidirectional wheels 12 are attached to the four mounting frames of the main body 11. The main body frame of the main body 11 is equipped with a control device that controls the movement of the mobile object 1, a power supply device that serves as a power source for the mobile object 1, and a communication device that wirelessly communicates between the mobile object 1 and a controller, etc.

[0014] The omnidirectional wheels 12 are attached to the underside of each mounting frame of the main body 11. The omnidirectional wheels 12 may be attached to the main body 11 so that the orientation of the rotation axes is N-fold symmetric (N is the number of omnidirectional wheels 12 included in the mobile body 1). For example, in the mobile body 1 shown in FIG. 1 , the omnidirectional wheels 12 may be attached to the main body 11 so that the orientation of the rotation axes is four-fold symmetric, with each rotation axis differing by 90 degrees.

[0015] The mobile body 1 can move forward and backward, diagonally, sideways, etc., or rotate on the spot by independently rotating the omnidirectional wheels 12 that can rotate in all directions.

[0016] 2. Wheel Structure (2.1. Configuration Examples) Configuration examples of the omnidirectional wheel 12 provided on the vehicle 1 will be described with reference to FIGS. 2 to 7. FIG. 2 is a perspective view of the omnidirectional wheel 12. FIG. 3 is a perspective view of the omnidirectional wheel 12 with one of the spherical annular wheels 71 removed. FIG. 4 is a perspective view of the first frame 62, the second frame 63, the spherical annular wheel 71, the auxiliary wheel 72, and the support member 73. FIG. 5 is a cross-sectional view of the omnidirectional wheel 12. FIG. 6 is a side view of the omnidirectional wheel 12 viewed from above in the axial direction of the first rotation axis. FIG. 7 is an explanatory diagram illustrating the shape requirements of the omnidirectional wheel 12.

[0017] As shown in FIG. 2 , the omnidirectional wheel 12 includes a pair of support members 52 , a bearing 53 , a rotating frame 61 , and three wheel units 64 .

[0018] The rotating frame 61 is a columnar member that is rotatable about a first rotation axis and extends in the axial direction of the first rotation axis. The upper and lower surfaces of the rotating frame 61 are sandwiched between a pair of support members 52, and the rotating frame 61 is rotatable about the first rotation axis via bearings 53. Three wheel units 64 are provided on the side surfaces of the columnar member of the rotating frame 61. The three wheel units 64 are provided 120 degrees apart from each other on the side surfaces of the columnar member of the rotating frame 61 so that the contact surface forms the surface of an imaginary sphere.

[0019] However, when the omnidirectional wheel 12 has four wheel units 64, the wheel units 64 may be provided at 90-degree intervals on the side surfaces of the columnar member of the rotating frame 61. When the omnidirectional wheel 12 has five wheel units 64, the wheel units 64 may be provided at 72-degree intervals on the side surfaces of the columnar member of the rotating frame 61.

[0020] 2 and 4, the rotating frame 61 includes a first frame 62 and a second frame 63. The first frame 62 and the second frame 63 are fitted together to form the rotating frame 61.

[0021] The first frame 62 and the second frame 63 may be made of a metal material such as an aluminum-based metal, a magnesium-based metal, an iron-based metal including stainless steel, or a titanium-based metal, or may be made of a resin material such as a fluororesin, a PEEK (PolyEtherEtherKetone)-based resin, or MC Nylon (registered trademark).

[0022] Flat portions 62C are provided on the side surface of the first frame 62 at equal intervals (for example, at intervals of 120 degrees) in the rotational direction of the first rotation shaft. The flat portions 62C are located approximately in the center of the rotating frame 61 when the first frame 62 and the second frame 63 form the rotating frame 61, and are portions to which the wheel units 64 are attached. The flat portions 62C may be provided spaced apart from each other by 120 degrees in the rotational direction of the first rotation shaft.

[0023] The first frame 62 and the second frame 63 have a hollow structure, and a first space 62B and a second space 63B are respectively provided inside the first frame 62 and the second frame 63. As shown in Fig. 5 , a drive unit 112, such as a motor that outputs rotational force, and an encoder 113 that controls the drive of the drive unit 112 are provided in the first space 62B and the second space 63B. In other words, the drive unit 112 is an in-wheel motor for the omnidirectional wheel 12.

[0024] The rotating frame 61 can rotate about the first rotation axis by receiving rotational force output from a drive unit 112 provided in the first space 62B and the second space 63B and transmitted from the output shaft 111. Furthermore, a cable 55 including wiring for supplying power to the drive unit 112 and wiring for transmitting control signals for the drive unit 112 and the encoder 113 is drawn out from the side opposite to the side where the output shaft 111 is provided.

[0025] The cable 55 may be drawn out toward the side where the main body 11 of the moving object 1 is located. In this case, the moving object 1 can further simplify the wiring connection between the main body 11 and the omnidirectional wheels 12.

[0026] Furthermore, when the omnidirectional wheel 12 is supported by one support member 52, it is preferable that the support member 52 supports the omnidirectional wheel 12 on the side where the main body 11 of the mobile object 1 is present. This prevents an object from being pinched between the support member 52 and the omnidirectional wheel 12 on the side opposite to the side where the main body 11 of the mobile object 1 is present. In such a case, the cable 55 may be pulled out toward the side where the main body 11 of the mobile object 1 is present, and the output shaft 111 may be provided toward the side opposite to the side where the main body 11 of the mobile object 1 is present.

[0027] Protrusions 61A are further provided on the side surfaces of the rotating frame 61. Specifically, the protrusions 61A are provided to protrude from the side surfaces of the rotating frame 61 (the first frame 62 or the second frame 63) extending on at least one side of the flat portion 62C, and extend in the axial direction of the first rotation axis. For example, the protrusions 61A may be provided to protrude from the side surfaces of the rotating frame 61 (the first frame 62 and the second frame 63) extending on both sides of the flat portion 62C, and extend in the axial direction of the first rotation axis. That is, the protrusions 61A may be provided on the side surfaces of both ends of the rotating frame 61 as fin-like structures protruding in a direction perpendicular to the first rotation axis of the rotating frame 61. Providing the protrusions 61A as fin-like structures extending in the axial direction of the first rotation axis ensures strength and improves durability, and can prevent the protrusions 61A from getting caught on cables or the like that are on the ground.

[0028] The protrusions 61A may be provided in multiple locations at equal intervals in the rotational direction of the first rotational axis so as to be rotationally symmetric when viewed from the axial direction of the first rotational axis. For example, if three protrusions 61A are provided, the protrusions 61A may be provided at 120-degree intervals in the rotational direction of the first rotational axis so as to be three-fold symmetric when viewed from the axial direction of the first rotational axis. This allows the protrusions 61A to maintain the center of gravity of the rotating frame 61, thereby allowing the rotating frame 61 to rotate smoothly without eccentricity around the first rotational axis. Furthermore, when the omnidirectional wheel 12 rotates, the protrusions 61A can create opportunities for the protrusions 61A to traverse steps multiple times per rotation as the rotating frame 61 rotates.

[0029] As shown in FIGS. 2 to 4, the wheel unit 64 includes a spherical wheel 71, an auxiliary wheel 72, a support member 73, a bearing 74, a bearing 75, and a sealing member .

[0030] 2 and 3 , the spherical annular wheel 71 is a wheel with a spherical trapezoidal shape obtained by cutting a sphere along a pair of parallel planes. The spherical annular wheel 71 is attached to a support member 73 via a bearing 74, allowing it to rotate about a second rotation axis perpendicular to the first rotation axis. This allows the spherical annular wheel 71 to passively rotate due to friction between the spherical annular side surface 71A, which serves as the contact surface, and the ground when the vehicle 1 is traveling. The spherical annular wheel 71 may be made of a resin material, such as a rubber-based resin, MC nylon (registered trademark), or a POM (Polyoxymethylene)-based resin.

[0031] 4, the spherical annular wheel 71 is provided with a through-hole 71B that widens from the top to the bottom of the spherical annular wheel 71. The auxiliary wheel 72, bearing 75, support member 73, and bearing 74 are housed inside the through-hole 71B.

[0032] As shown in FIG. 3 , the auxiliary wheel 72 is a barrel-shaped wheel with a hollow structure. The auxiliary wheel 72 is attached to a support member 73 via a bearing 75, and is capable of rotating about a third rotation axis that is perpendicular to the second rotation axis and twisted relative to the first rotation axis. This allows the auxiliary wheel 72 to passively rotate due to friction between the ground and the ring-shaped side surface exposed through the through-hole 71B of the spherical wheel 71 while the vehicle 1 is traveling. The auxiliary wheel 72 may be made of a resin material, such as rubber-based resin, MC nylon (registered trademark), or POM (Polyoxymethylene)-based resin.

[0033] The support member 73 is a member that supports the spherical annular wheel 71 and the auxiliary wheel 72. Specifically, a bearing 75 and the auxiliary wheel 72 are provided inside a through hole 73A provided in the center of the support member 73, facing laterally (i.e., perpendicular to the direction in which the through hole 73A penetrates). This allows the auxiliary wheel 72 to rotate around a third rotation axis that is perpendicular to the second rotation axis and twisted relative to the first rotation axis and perpendicular to it, via the bearing 75. In addition, the spherical annular wheel 71 is provided on the outer surface of the support member 73 via a bearing 74. This allows the spherical annular wheel 71 to rotate around a second rotation axis that is perpendicular to the first rotation axis, via the bearing 74.

[0034] The sealing member 76 is a member for sealing the through hole 71B of the spherical annular wheel 71. The sealing member 76 is fixed to the spherical annular wheel 71 with a screw or the like, thereby sealing the bearing 74 inside the through hole 71B and preventing the spherical annular wheel 71 from falling off the support member 73.

[0035] The wheel units 64 may be provided at 120-degree intervals around the circumferential direction of the first rotation shaft so as to be three-fold symmetric when viewed from the axial direction of the first rotation shaft. In this way, the wheel units 64 can maintain the center of gravity at the center of the rotating frame 61, allowing the rotating frame 61 to rotate smoothly around the first rotation shaft without eccentricity.

[0036] 6, the wheel units 64 and the protrusions 61A may be provided alternately on the side surfaces of the rotating frame 61. Specifically, the wheel units 64 may be arranged at equal intervals (for example, at intervals of 120 degrees) in the rotation direction of the first rotation shaft, and the protrusions 61A may be arranged between the wheel units 64 at equal intervals (for example, at intervals of 120 degrees) in the rotation direction of the first rotation shaft.

[0037] In such a case, the protrusions 61A may be disposed midway between the wheel units 64. That is, the wheel units 64 and the protrusions 61A may be disposed alternately at equal intervals (e.g., 60-degree intervals) in the rotational direction of the first rotation axis. This allows the wheel units 64 and the protrusions 61A to maintain the center of gravity of the rotating frame 61 at the center, thereby enabling the rotating frame 61 to rotate smoothly around the first rotation axis without eccentricity. Furthermore, arranging the wheel units 64 and the protrusions 61A at equal intervals increases the commonality of parts, thereby improving the maintainability of the omnidirectional wheel 12. Furthermore, disposing the protrusions 61A between the wheel units 64 allows the omnidirectional wheel 12 to more easily approach steps when traversing them.

[0038] According to the above configuration, each of the spherical annular wheels 71 is provided on a side surface (flat portion 62C) of the rotating frame 61 so as to be rotatable about a second rotation axis that is perpendicular to the first rotation axis of the rotating frame 61. The side surface 71A, which is the contact surface of each of the spherical annular wheels 71, constitutes part of the spherical surface of a common imaginary sphere. This allows the omnidirectional wheel 12 to rotate as a virtual sphere whose spherical surface is constituted by the side surfaces 71A of each of the spherical annular wheels 71.

[0039] Each auxiliary wheel 72 is provided inside the through-hole 73A of the support member 73 via a bearing 75 so as to be rotatable about a third rotation axis that is perpendicular to both the first rotation axis of the rotating frame 61 and the second rotation axis of the corresponding spherical annular wheel 71. Each auxiliary wheel 72 can rotate on the ground contact surface exposed from the opening (through-hole 71B) at the top of the spherical annular wheel 71 while the mobile object 1 is traveling.

[0040] Therefore, the omnidirectional wheels 12 are capable of movement in all directions. Specifically, the omnidirectional wheels 12 are capable of movement in the forward / backward direction perpendicular to the axial direction of the first rotation axis by actively rotating the rotating frame 61. Furthermore, each of the omnidirectional wheels 12 is capable of movement in all directions other than the forward / backward direction by passively rotating each of the spherical annular wheels 71. Furthermore, when the auxiliary wheels 72 exposed at the top of the spherical annular wheels 71 are in contact with the ground, each of the omnidirectional wheels 12 is capable of movement in the axial direction of the first rotation axis by passively rotating each of the auxiliary wheels 72. Therefore, the omnidirectional wheels 12 can improve the running performance of the mobile object 1.

[0041] 7A and 7B , the omnidirectional wheel 12 according to this embodiment has spherical annular wheels 71 arranged in three directions, which allows the drive unit 112 to be arranged as an in-wheel motor in the internal space formed by the spherical trapezoidal shape of the three spherical annular wheels 71. By arranging the spherical annular wheels 71 in three directions, the gap between the spherical annular wheels 71 can be reduced, thereby further reducing vibrations caused by the omnidirectional wheel 12 while traveling.

[0042] Furthermore, when the drive unit 112 is provided as an in-wheel motor, the drive unit 112 and the rotating frame 61 are integrated into one unit, which makes it possible to further reduce the size of the mobile object 1 and more easily attach or detach the omnidirectional wheels 12. Furthermore, when the drive unit 112 is provided as an in-wheel motor, the drive unit 112 is stored inside the rotating frame 61, which reduces the risk of the drive unit 112 coming into contact with the ground or the like when traversing rough terrain.

[0043] Here, the shape conditions of the omnidirectional wheel 12 will be described with reference to FIGS.

[0044] As shown in Figures 5 to 7, in the omnidirectional wheel 12, approximately one-quarter of the diameter HD of the omnidirectional wheel 12 is covered by the structure of the spherical annular wheel 71. Therefore, it is preferable that the diameter MD of the drive unit 112 be less than one-half of the diameter HD of the omnidirectional wheel 12. Furthermore, because it is important that the drive unit 112, which is an in-wheel motor, is completely covered by the rotating frame 61, it is preferable that the diameter MD of the drive unit 112 be less than one-half of the diameter HD of the omnidirectional wheel 12. On the other hand, a structure in which a drive unit 112 that is more than one-half the diameter HD of the omnidirectional wheel 12 is provided inside the rotating frame 61 is not preferable in terms of ease of disassembly and assembly of the omnidirectional wheel 12. In reality, it is preferable that the diameter MD of the drive unit 112, which is an in-wheel motor, be approximately one-third of the diameter HD of the omnidirectional wheel 12.

[0045] Furthermore, the length MW of the driver 112 and the encoder 113 in the axial direction of the first rotation shaft of the rotating frame 61 is preferably equal to or less than 3 / 2 of the diameter HW of the omnidirectional wheel 12. If the length MW of the driver 112 and the encoder 113 in the axial direction of the first rotation shaft of the rotating frame 61 exceeds 3 / 2 of the diameter HW of the omnidirectional wheel 12, it becomes difficult to reduce the size of the omnidirectional wheel 12, which is not preferable.

[0046] (2.2. Operational Example) An operational example of step traversal by the omnidirectional wheel 12 will be described with reference to Figs. 8 to 10. Fig. 8 is a plan view of the omnidirectional wheel 12 as viewed from above the ground. Fig. 9 is a perspective view showing the movement of the omnidirectional wheel 12 when traversing a step S. Fig. 10 is a perspective view showing the movement of the omnidirectional wheel 12 when traversing a step S by moving in the axial direction of the first rotation axis of the rotating frame 61.

[0047] 8 , in the omnidirectional wheel 12, a rotating frame 61 protrudes from a virtual sphere formed by a plurality of wheel units 64, and a protrusion 61A is provided on the side of the protruding rotating frame 61. Because the protrusion 61A protrudes from the virtual sphere formed by the plurality of wheel units 64, it is possible for the protrusion 61A to come into contact with a step before the omnidirectional wheel 12 does when the omnidirectional wheel 12 moves in the traveling direction F.

[0048] In such a case, as shown in Figure 9, the omnidirectional wheel 12 can lift the omnidirectional wheel 12, including the rotating frame 61, above the step S by hooking the protrusions 61A, which rotate in conjunction with the rotation of the rotating frame 61, onto the step S. Therefore, by actively hooking the protrusions 61A onto the step S, the omnidirectional wheel 12 can further improve its ability to traverse steps on uneven ground. For example, the omnidirectional wheel 12 can traverse a step S that is larger than the radius of the omnidirectional wheel 12. Furthermore, the omnidirectional wheel 12 can have a compact and lightweight structure with a reduced number of parts while increasing the strength of the entire structure, making maintenance easier.

[0049] When traversing a step S using the protrusions 61A, it is important to rotate the omnidirectional wheels 12 with momentum only at the moment of traversing the step S. For example, even if the omnidirectional wheels 12 climb up the step S by hooking the protrusions 61A onto the step S, which rotates slowly, they may fail to transfer from the protrusions 61A to the wheel units 64 and fall off the step S. Therefore, the mobile object 1 may rotate the rotating frame 61 with momentum at the moment the protrusions 61A hook onto the step S, thereby allowing the omnidirectional wheels 12 to float above the step S and climb up it using the momentum of the rotation. This allows the mobile object 1 to carry the wheel units 64 up the step S more smoothly.

[0050] However, if the rotating frame 61 is rotated with momentum, the moment the wheel unit 64 steps onto the step S, friction may occur between the wheel unit 64 and the upper surface of the step S, causing the omnidirectional wheels 12 to start moving at high speed. To prevent this situation, the mobile object 1 may rotate only the omnidirectional wheels 12 that are traversing the step S with momentum, while allowing the other omnidirectional wheels 12 to rotate at their original speed without momentum.

[0051] When using the protrusion 61A to traverse the step S, it is desirable to gain momentum and rotate the omnidirectional wheel 12 immediately after the protrusion 61A gets caught on the step S. The timing at which the protrusion 61A gets caught on the step S can be detected, for example, by the following method.

[0052] For example, the timing when the protrusion 61A gets caught on the step S can be detected by a current sensor that measures the current flowing through the drive units 112 that rotate each of the rotating frames 61. Specifically, when the protrusion 61A gets caught on the step S, the torque that rotates the rotating frame 61 increases, and the current flowing through the drive units 112 also increases. Therefore, the moving body 1 can detect the timing when the protrusion 61A gets caught on the step S by detecting the moment when the current flowing through the drive units 112 increases using the current sensor.

[0053] For example, the timing when the protrusion 61A gets caught on the step S can be detected by an IMU (Inertial Measurement Unit) or an acceleration sensor provided inside or near each omnidirectional wheel 12 (e.g., on a mounting frame of the main body 11 directly above the omnidirectional wheel 12). Specifically, when the protrusion 61A gets caught on the step S, the omnidirectional wheel 12 begins to rise, and acceleration due to the rise is applied to the omnidirectional wheel 12. Therefore, the mobile object 1 can detect the timing when the protrusion 61A gets caught on the step S by detecting the acceleration applied to the omnidirectional wheel 12 with the IMU or acceleration sensor.

[0054] For example, the timing when the protrusion 61A gets caught on the step S can be detected by a camera mounted on the main body 11 of the mobile object 1. Specifically, when any of the protrusions 61A gets caught on the step S, the main body 11 of the mobile object 1 begins to rise, and the field of view of the camera mounted on the main body 11 also begins to rise. Therefore, the mobile object 1 can detect the timing when the protrusion 61A gets caught on the step S by detecting the moment when the image captured by the camera starts to rise. Note that the cameras mounted on the main body 11 of the mobile object 1 do not correspond to each of the omnidirectional wheels 12, so it may be difficult to determine from the camera image which of the omnidirectional wheels 12 the protrusion 61A has gotten caught on the step S. In such a case, the mobile object 1 can determine which of the omnidirectional wheels 12 the protrusion 61A has gotten caught on the step S by rotating each of the omnidirectional wheels 12 one by one and checking whether the camera image has risen each time.

[0055] On the other hand, when traversing a step S using the protrusion 61A, it is desirable to stop the rotational momentum of the omnidirectional wheel 12 immediately after the omnidirectional wheel 12 has finished climbing the step S or immediately after the omnidirectional wheel 12 has fallen from the step S. The timing when the omnidirectional wheel 12 has finished climbing the step S or fallen from the step S can be detected, for example, by the following method.

[0056] For example, the timing when the omnidirectional wheel 12 has climbed the step S or fallen off the step S can be detected by a current sensor that measures the current flowing through the drive unit 112 that rotates each of the rotating frames 61. Specifically, when the omnidirectional wheel 12 has climbed the step S or fallen off the step S and the protrusion 61A that was caught on the step S becomes detached from the step S, the torque that rotates the rotating frame 61 decreases, and the current flowing through the drive unit 112 also decreases. Therefore, the mobile object 1 can detect the timing when the omnidirectional wheel 12 has climbed the step S or fallen off the step S by detecting the moment when the current flowing through the drive unit 112 decreases using a current sensor.

[0057] For example, the timing when the omnidirectional wheel 12 has climbed the step S or fallen from the step S can be detected by an IMU (Inertial Measurement Unit) or an acceleration sensor provided inside or near each omnidirectional wheel 12 (e.g., on a mounting frame of the main body 11 directly above the omnidirectional wheel 12). Specifically, when the omnidirectional wheel 12 has climbed the step S or fallen from the step S, the omnidirectional wheel 12 receives an impact from landing after climbing the step S or falling from the step S. Therefore, the mobile object 1 can detect the timing when the omnidirectional wheel 12 has climbed the step S or fallen from the step S by detecting the impact applied to the omnidirectional wheel 12 using the IMU or acceleration sensor.

[0058] For example, the timing when the omnidirectional wheel 12 has climbed the step S or fallen off the step S can be detected by a microphone provided inside or near each omnidirectional wheel 12 (such as on a mounting frame of the main body 11 directly above the omnidirectional wheel 12). Specifically, when the omnidirectional wheel 12 has climbed the step S or fallen off the step S, an impact sound is generated when the omnidirectional wheel 12 lands on the step S or falls off the step S. Therefore, the mobile object 1 can detect the timing when the omnidirectional wheel 12 has climbed the step S or fallen off the step S by detecting the impact sound generated near the omnidirectional wheel 12 with the microphone.

[0059] For example, the timing when the omnidirectional wheel 12 has climbed the step S or fallen off the step S can be detected by a camera mounted on the main body 11 of the moving object 1. Specifically, when the omnidirectional wheel 12 has climbed the step S or fallen off the step S, the movement of the field of view of the camera mounted on the main body 11 changes. Therefore, the moving object 1 can detect the timing when the omnidirectional wheel 12 has climbed the step S or fallen off the step S by detecting a change in the movement (such as shaking) of the image captured by the camera.

[0060] The moving body 1 can estimate the height of the step S by referring to the detection results of a sensor, such as an encoder or a Hall sensor, that detects the angle of the rotating frame 61, in addition to the timing when the protrusion 61A gets caught on the step S and the timing when the omnidirectional wheel 12 finishes climbing the step S. Specifically, the moving body 1 can estimate the height of the step S by using the angle of the protrusion 61A when the protrusion 61A gets caught on the step S, the angle of the protrusion 61A when the omnidirectional wheel 12 finishes climbing the step S, and the radius of the omnidirectional wheel 12.

[0061] If an image of the step S can be captured using a camera or the like, the mobile body 1 can estimate the height of the step S as a specific numerical value from the captured image. Furthermore, the mobile body 1 can estimate the distance to the step S by detecting the step S using the captured image, and control the rotation of the omnidirectional wheels 12 by idling so that the phases of the protrusions 61A of the omnidirectional wheels 12 are aligned when approaching the step S. In this way, the mobile body 1 is less likely to slip down the step S due to the phases of the protrusions 61A of the omnidirectional wheels 12 being aligned, thereby enabling the mobile body 1 to traverse the step S more stably. Furthermore, the phases of the omnidirectional wheels 12 being aligned allows the mobile body 1 to travel more smoothly on flat surfaces.

[0062] Furthermore, when the omnidirectional wheel 12 is moved in the axial direction of the first rotation axis of the rotating frame 61, the rotating frame 61 does not rotate, and it may be difficult to hook the protrusion 61A provided on the rotating frame 61 onto the step S.

[0063] In such a case, as shown in Figure 10, the mobile object 1 first rotates the omnidirectional wheel 12 so that the protrusion 61A is positioned so that it does not interfere with the step S. Then, the mobile object 1 moves the omnidirectional wheel 12 in the axial direction of the first rotation axis of the rotating frame 61 to position the protrusion 61A in the space above the step S. Next, the mobile object 1 rotates the omnidirectional wheel 12 to position the protrusion 61A upright above the step S, thereby allowing the protrusion 61A to lift the omnidirectional wheel 12 above the step S. This allows the mobile object 1 to improve its ability to traverse the step S with only a small amount of left and right movement relative to its direction of travel.

[0064] In order to improve the ability of the mobile body 1 to overcome obstacles in all directions, it is desirable that the center of gravity of the entire mobile body 1 be near the center of a polygon whose vertices are the locations of the omnidirectional wheels 12. This allows the mobile body 1 to improve its ability to overcome obstacles in all directions, including the front, rear, left, and right, without bias.

[0065] On the other hand, if the overall center of gravity of the moving body 1 is biased in one direction, it is desirable that the moving body 1 ascend and descend the step S so that the direction in which the center of gravity is biased is at a higher position. For example, when the moving body 1 with a biased center of gravity descends the step S, it is desirable that the moving body 1 descends the step S from the side opposite to the side in which the center of gravity is biased, so that the side in which the center of gravity is biased remains on the upper side of the step S. Furthermore, when the moving body 1 with a biased center of gravity climbs the step S, it is desirable that the moving body 1 climbs the step S from the side in which the center of gravity is biased.

[0066] 3. Modifications First to fifteenth modifications of the omnidirectional wheel 12 according to this embodiment will be described with reference to FIGS. 11 to 31. FIG.

[0067] 11 to 13 are perspective views of an omnidirectional wheel 12A according to a first modification. As shown in Fig. 11 to 13, a rubber member 81 may be further provided at the tip of the protrusion 61A on the side opposite to the side where the wheel unit 64 is provided.

[0068] 11 , the rubber member 81 is made of, for example, a rubber material with a higher friction coefficient than the rotating frame 61, and replaces a part of the tip of the protrusion 61A. The higher the friction force of the protrusion 61A, the easier it is to traverse steps. Therefore, by providing the rubber member 81 at the tip of the protrusion 61A, the step-traversing performance of the omnidirectional wheel 12A can be further improved.

[0069] The tip of the protrusion 61A on which the rubber member 81 is provided is the portion that first comes into contact with a step, and is therefore susceptible to large impacts and damage. For this reason, it is preferable that the rubber member 81 be provided in an easily replaceable manner. For example, the rubber member 81 may be screwed to the protrusion 61A in a direction parallel to the axial direction of the first rotation shaft of the rotating frame 61. By screwing the rubber member 81 in a direction parallel to the axial direction of the first rotation shaft of the rotating frame 61, the rubber member 81 is more firmly fastened to the protrusion 61A.

[0070] According to the omnidirectional wheel 12A of the first modification, by providing the rubber member 81 on the protrusion 61A, it is possible to improve the step-crossing performance and improve the maintainability of the protrusion 61A.

[0071] 12 , the rubber member 81 may be provided to be freely rotatable about an axis parallel to the first rotation axis of the rotating frame 61. For example, the rubber member 81 may be attached to the protrusion 61A via a bearing, thereby being freely rotatable about the axis parallel to the first rotation axis. This allows the rubber member 81 to freely rotate about the axis parallel to the first rotation axis, thereby preventing the force in the rotational direction of the rotating frame 61 from acting on the step when the omnidirectional wheel 12A comes into contact with the step. Therefore, the omnidirectional wheel 12A can prevent damage to the step caused by the rubber member 81, thereby improving its suitability for environments with delicate steps.

[0072] Furthermore, as shown in FIG. 13 , the rubber member 81 may be provided so as to cover the entire protruding end of the protruding portion 61A. Specifically, the rubber member 81 may be provided in a rectangular parallelepiped shape extending in a direction parallel to the first rotation axis of the rotating frame 61 and may be provided so as to replace the entire protruding end of the raising portion 61A. The cross-sectional shape of the end of the rubber member 81 cut along a plane perpendicular to the first rotation axis may be, for example, a hemispherical shape, a parabolic shape, or a rounded rectangle. The rubber member 81 may be coupled to the protruding portion 61A by fastening it to the protruding portion 61A with a screw, for example, via a screw hole provided through the rubber member 81 in the protruding direction of the protruding portion 61A. Alternatively, the rubber member 81 may be coupled to the protruding portion 61A by fitting a concave-convex shape extending in a direction parallel to the first rotation axis into the protruding portion 61A.

[0073] 14 is a perspective view of an omnidirectional wheel 12B according to a second modification. As shown in FIG. 14, the protrusion 61A may further include a belt member 82 that is stretched around the entire periphery of the side surface of the rotating frame 61.

[0074] The belt member 82 is made of, for example, a rubber material with a higher friction coefficient than the rotating frame 61, and is stretched around the entire periphery of the side of the rotating frame 61 with tension applied between the multiple protrusions 61A. The higher the friction force of the protrusions 61A, the easier it is to traverse steps. Therefore, by stretching the belt member 82 around the entire periphery of the side of the rotating frame 61, the step-traversing performance of the omnidirectional wheels 12B can be further improved.

[0075] The belt member 82 may be fixed to the multiple protrusions 61A and the rotating frame 61 by the tension of the rubber material, or may be fixed to the multiple protrusions 61A and the rotating frame 61 by being clamped on both sides with members such as screws.

[0076] According to the omnidirectional wheel 12B of the second modification, the belt member 82 is provided on the protrusion 61A, thereby making it possible to improve the step-crossing performance.

[0077] 15 is a partial perspective view of an omnidirectional wheel 12C according to a third modification. As shown in Fig. 15, the rotating frame 61 may further be provided with a cover member 83 that covers the end opposite to the end where the wheel unit 64 is provided.

[0078] The cover member 83 is made of, for example, a rubber material with a higher friction coefficient than the rotating frame 61, and is provided so as to cover the end of the rotating frame 61 opposite the side where the wheel unit 64 is provided. Specifically, the cover member 83 may have a shape that matches the shape of the rotating frame 61 and the multiple protrusions 61A provided on the side of the rotating frame 61, and may cover the rotating frame 61 and the multiple protrusions 61A. The higher the friction force of the protrusions 61A, the easier it is for the omnidirectional wheels 12C to traverse steps. Therefore, by covering the rotating frame 61 including the protrusions 61A with the cover member 83, the step-traversing performance of the omnidirectional wheels 12C can be further improved.

[0079] According to the omnidirectional wheel 12C of the third modified example, by providing a cover member 83 on the rotating frame 61, it is possible to improve the step-crossing performance.

[0080] 16 is a side view of an omnidirectional wheel 12D according to a fourth modification, viewed from the axial direction of the first rotation axis. As shown in FIG. 16, the rotating frame 61 may have a triangular or rounded triangular shape when viewed from the axial direction of the first rotation axis. For example, the rotating frame 61 may have an equilateral triangular shape or a rounded equilateral triangular shape when viewed from the axial direction of the first rotation axis.

[0081] In such a case, the vertices of the triangular or rounded triangular shape of the rotating frame 61 can be used as the protrusions 61A, which allows the structure of the rotating frame 61 to be further simplified.

[0082] Furthermore, if the rotating frame 61 is triangular or triangular with rounded corners, the shape of the belt member 82 described in the second modified example or the cover member 83 described in the third modified example can be simplified to match the shape of the rotating frame 61. As a result, the omnidirectional wheel 12D according to the fourth modified example can improve the strength of the belt member 82 or the cover member 83 and make it easier to attach the belt member 82 or the cover member 83 to the rotating frame 61.

[0083] According to the omnidirectional wheel 12D of the fourth modified example, the structure of the rotating frame 61 can be further simplified, thereby improving the strength of the rotating frame 61 and the members attached to the rotating frame 61.

[0084] 17 is a perspective view of an omnidirectional wheel 12E according to a fifth modification. As shown in FIG. 17, a recess 84 may be provided on the upper surface of the protrusion 61A in the protruding direction. Specifically, the recess 84 is a depression extending in the rotation direction of the first rotation shaft, and is provided on the upper surface of the protrusion 61A in a direction perpendicular to the axial direction of the first rotation shaft.

[0085] When the omnidirectional wheel 12E travels over the ground, thin, flexible objects such as hair, thread, string, or wiring may become entangled around the wheel 12E. If such thin, flexible objects get caught in the narrow gap between the support member 52 and the rotating frame 61 or between the rotating frame 61 and the wheel unit 64, frictional resistance will be generated by the trapped object when the omnidirectional wheel 12E rotates. Therefore, the frictional resistance will cause a decrease in controllability, a decrease in rotational speed, or energy loss in the omnidirectional wheel 12E.

[0086] The omnidirectional wheel 12E can collect wrapped objects in the recesses 84 provided in the protrusions 61A by taking advantage of the fact that objects wrapped around the rotating frame 61 gather at the smallest diameter portion of the rotating frame 61. Therefore, the omnidirectional wheel 12E can prevent objects wrapped around the rotating frame 61 from getting between the support member 52 and the rotating frame 61 or between the rotating frame 61 and the wheel unit 64.

[0087] In addition, by utilizing the recess 84 provided in the protrusion 61A, the omnidirectional wheel 12E can also fix the belt member 82 described in the second modified example or the cover member 83 described in the third modified example to the protrusion 61A.

[0088] The omnidirectional wheel 12E according to the fifth modification can prevent performance degradation caused by objects getting caught in the wheel when the wheel is traveling on the ground.

[0089] 18 to 21 are side views of an omnidirectional wheel 12F according to a sixth modification. As shown in FIGS. 18 and 19, the support member 52 may have a tapered planar shape that narrows toward the connection point with the rotating frame 61 when viewed from above in the axial direction of the first rotation axis of the rotating frame 61. This prevents the support member 52 from interfering with the step before the protrusion 61A does when traversing the step.

[0090] Furthermore, a recessed structure 52A may be further provided midway along the tapered slope of the side surface of the support member 52. Specifically, a recessed structure 52A recessed toward the inside of the planar shape may be further provided on the side surface of the support member 52 that is tapered toward the connection point of the support member 52 with the rotating frame 61. With this, when an object is about to be pinched between the support member 52 and the protrusion 61A that rotates with the rotation of the rotating frame 61, the recessed structure 52A can be used to release the object from being pinched. Specifically, when an object is pushed by the protrusion 61A and is about to be pinched between the protrusion 61A and the support member 52, the object pushed by the protrusion 61A can be moved along the slope of the recessed structure 52A, thereby releasing the object from being pinched.

[0091] For example, as shown in Figure 18, the recessed structure 52A may be a structure that is recessed from a straight line (i.e., a tapered inclined straight line) connecting the side of the end attached to the main body 11 of the support member 52 and the side of the end on the connection point side with the rotating frame 61 of the support member 52 toward the inside of the planar shape of the support member 52.

[0092] 19, the recessed structure 52A may have a larger depression amount than the recessed structure 52A shown in Fig. 18, and may have a structure in which the planar shape of the support member 52 is constricted midway along the tapered slope. In such a case, the width of the support member 52 on the connection point side with the rotating frame 61 from the recessed structure 52A will be wider in the width direction than the width of the planar shape constricted by the recessed structure 52A.

[0093] 20, the support member 52 may be provided in a planar shape that is not tapered when viewed from above in the axial direction of the first rotation axis of the rotating frame 61. In such a case, the support member 52 is made of a high-strength material, which allows the end of the support member 52 on the connection point side with the rotating frame 61 to have a more compact shape while maintaining the attachment strength to the main body 11.

[0094] 21 , the support member 52 may be provided in a non-tapered planar shape, and may be provided in a shape in which the end of the support member 52 on the side of the connection point with the rotating frame 61 is bulged. In such a case, a recessed structure 52A is formed on the side of the support member 52, recessed toward the inside of the planar shape of the support member 52 from a straight line connecting the side of the end of the support member 52 attached to the main body 11 and the side of the end of the support member 52 on the side of the connection point with the rotating frame 61.

[0095] The omnidirectional wheel 12F according to the sixth modification can prevent an object from being caught between the support member 52 and the protrusion 61A that rotates in conjunction with the rotation of the rotating frame 61.

[0096] (Seventh Modification) Fig. 22 is a partial side view of an omnidirectional wheel 12G according to a seventh modification. As shown in Fig. 22, the support member 52 may further be provided with an opening 52B.

[0097] Opening 52B is provided through support member 52 at a position that allows access to the outer periphery of rotating frame 61 and bearing 53. Opening 52B facilitates access to the outer periphery of rotating frame 61 and bearing 53, thereby making it easier to remove objects such as hair, thread, string, or wiring that has become entangled between rotating frame 61 and support member 52. However, in order to prevent a user's fingers or the like from getting caught in opening 52B, opening 52B is preferably provided to be large enough to prevent fingers from entering but large enough to allow nippers, tweezers, or the like to enter.

[0098] According to the omnidirectional wheel 12G of the seventh modified example, it is possible to more easily remove objects that have become entangled between the rotating frame 61 and the support member 52, thereby improving the maintainability of the omnidirectional wheel 12G.

[0099] 23 is a partial perspective view of an omnidirectional wheel 12H according to an eighth modification. As shown in FIG. 23 , the support member 52 may further be provided with a protection portion 56 for protecting the cable 55.

[0100] Cable 55, which includes wiring for supplying power to drive unit 112 and wiring for transmitting control signals from drive unit 112 and encoder 113, passes near the center of the first rotation axis of rotating frame 61 and is pulled out to the outside of rotating frame 61. Protective unit 56 covers the top or bottom surface of rotating frame 61 from which cable 55 is pulled out, thereby preventing dust or moisture from entering the interior of rotating frame 61.

[0101] Specifically, the protective portion 56 may be smaller and thinner than the support member 52. This prevents the omnidirectional wheel 12H from interfering with steps when it travels over them. Furthermore, the protective portion 56 is smoothly connected to the support member 52 without any misalignment, thereby more reliably preventing dust or moisture from entering the interior of the rotating frame 61. It is preferable that the cable 55 extending further from the protective portion 56 be drawn from an upper portion of the protective portion 56 that is farther from the ground to prevent dust or moisture from entering from the ground.

[0102] According to the omnidirectional wheel 12H of the eighth variant, by providing a protective part 56 that protects the cable 55 pulled out from inside the rotating frame 61, it is possible to further improve the waterproof, drip-proof, and dust-proof properties of the omnidirectional wheel 12H.

[0103] 24 is a perspective view of an omnidirectional wheel 12I according to a ninth modification. As shown in FIG. 24, the support member 52 may have a structure in which a plurality of flat plate-shaped members are bonded together in the thickness direction.

[0104] Specifically, the support member 52 may have a structure in which a first member 52B and a second member 52C are bonded together in the thickness direction. The first member 52B is a flat plate-like member that extends from the connection point with the rotating frame 61 to the height of the protrusion 61A. The second member 52C is a flat plate-like member that is bonded to an end of the first member 52B on the surface opposite to the surface on which the rotating frame 61 is provided, and that further extends from the end of the first member 52B.

[0105] The support member 52 is provided with a structure in which the first member 52B and the second member 52C are bonded together, and thus a space 52D can be provided above the end of the rotating frame 61 connected to the support member 52. As a result, when an object is about to be pinched between the support member 52 and the protrusion 61A that rotates as the rotating frame 61 rotates, the support member 52 can use the space 52D to release the object from being pinched.

[0106] The support member 52 may be formed such that only one of the two sides that sandwich the rotating frame 61 has the structure of the first member 52B and the second member 52C bonded together, or such that both of the two sides have the structure of the first member 52B and the second member 52C bonded together. However, the side opposite the side where the main body 11 of the movable body 1 is present is more likely to trap an object present in the external environment. Therefore, it is preferable that the support member 52 on the side opposite the side where the main body 11 of the movable body 1 is present has the structure of the first member 52B and the second member 52C bonded together.

[0107] The first member 52B and the second member 52C may be separate members, or may be integrally processed or molded members. The support member 52 may be provided with another structure as long as it is possible to provide a space 52D above the end of the rotating frame 61 connected to the support member 52. For example, the support member 52 may be provided with a structure that extends at an angle from the connection point with the rotating frame 61 in a direction away from the rotating frame 61.

[0108] The omnidirectional wheel 12I according to the ninth modification can prevent an object from being pinched between the support member 52 and the protrusion 61A that rotates in conjunction with the rotation of the rotating frame 61.

[0109] (Tenth Modification) Fig. 25 is a side view showing an example of an omnidirectional wheel 12J according to a tenth modification. Fig. 26 is a perspective view showing another example of an omnidirectional wheel 12J according to the tenth modification. As shown in Figs. 25 and 26, the protrusion 61A may further be provided with an alert member 85 that alerts nearby users.

[0110] The alert member 85 may be a fluorescent member, a phosphorescent member, or a reflective member capable of reflecting light, which can emit light without requiring a power source or wiring. For example, the alert member 85 may be fluorescent tape or phosphorescent tape. The alert member 85 may be provided on a side surface of the protrusion 61A in the axial direction of the first rotation shaft, as shown in FIG. 25 , or on an upper surface or side surface of the protrusion 61A in the protruding direction, as shown in FIG. 26 . By providing the alert member 85 on the protrusion 61A, the omnidirectional wheel 12J can easily allow the user to recognize whether the protrusion 61A is rotating.

[0111] The omnidirectional wheel 12J according to the tenth modification allows the user to easily recognize the presence of the rotating protrusion 61A, thereby attracting the user's attention.

[0112] In order to alert the user, the omnidirectional wheel 12J or the moving body 1 can emit a warning sound or shine a warning light at the user's feet when it detects the user's approach.

[0113] 27 is a perspective view showing an omnidirectional wheel 12K according to an eleventh modification. As shown in FIG. 27 , a protective portion 86 that covers a gap between the rotating frame 61 and the wheel unit 64 may be further provided between the rotating frame 61 and the wheel unit 64.

[0114] The protective portion 86 is, for example, a member having a spherical surface shape with a radius smaller than that of an imaginary sphere whose surface is formed by the contact surface of the wheel unit 64, and is provided between the side surface of the rotating frame 61 and the wheel unit 64. By providing the protective portion 86, the omnidirectional wheel 12K can prevent an object from getting caught in the gap between the rotating frame 61 and the wheel unit 64.

[0115] The omnidirectional wheel 12K according to the eleventh modified example can prevent objects from getting caught in it, thereby increasing safety during rotation and suppressing energy loss and damage to the structure due to the objects getting caught in it.

[0116] 28 is a perspective view showing an omnidirectional wheel 12L according to a twelfth modification. As shown in Fig. 28, a frame member 58 having a recessed shape 58A corresponding to the outer shape of the wheel unit 64 of the omnidirectional wheel 12L may be further provided on the upper portion of the support member 52.

[0117] The frame member 58 is provided, for example, above the pair of support members 52 that sandwich the rotating frame 61, so as to bridge the space between the pair of support members 52. The frame member 58 is also provided with a concave shape 58A that corresponds to the virtual spherical surface formed by the contact surfaces of the wheel units 64. When the omni-directional wheels 12L rotate, the frame member 58 can automatically brush away dust and other particles adhering to the contact surfaces of the wheel units 64 through the gap between the wheel units 64 and the concave shape 58A. The frame member 58 may be formed of a rigid flat plate.

[0118] The frame member 58 may also have a brush provided in the recessed portion 58A facing the wheel unit 64. The brush provided in the recessed portion 58A can remove powdery dust and other particles adhering to the surface of the omnidirectional wheel 12L. It is desirable that the brush provided in the frame member 58 or the recessed portion 58A be easily replaceable for washing or cleaning, for example.

[0119] However, it is preferable that the frame member 58 be provided in a shape that creates a space 58B above the end of the rotating frame 61 that is connected to the support member 52. This makes it possible for the frame member 58 to prevent an object from being caught between the frame member 58 and the protrusion 61A that rotates as the rotating frame 61 rotates.

[0120] According to the omnidirectional wheel 12L of the twelfth modified example, dirt adhering to the contact surface of the wheel unit 64 can be automatically removed during rotation, making it easier to maintain driving performance.

[0121] It is also possible to attach to the frame member 58 a controller or driver of the drive unit 112 that rotates the rotating frame 61, a sensor for detecting the state of the omnidirectional wheels 12L, and the like.

[0122] 29 is a perspective view showing an omnidirectional wheel 12O according to a thirteenth modification. As shown in FIG. 29, the support member 52 may further be provided with a protruding member 87 that rotates coaxially with the rotating frame 61.

[0123] The protruding member 87 has protrusions 87A that protrude in a direction perpendicular to the first rotation axis of the rotating frame 61 at positions corresponding to the protrusions 61A provided on the side of the rotating frame 61, and is provided on the side of the support member 52 opposite to the side that clamps the rotating frame 61. For example, when viewed from above in the axial direction of the first rotation axis of the rotating frame 61, the protruding member 87 may have a planar shape in which the protrusions 87A corresponding to the protrusions 61A provided on the side of the rotating frame 61 protrude radially at equal intervals. The protruding member 87 can rotate around the first rotation axis in synchronization with the rotating frame 61. This allows the omnidirectional wheel 12O to hook onto steps using the protrusions 61A provided on the side of the rotating frame 61 as well as the protrusions 87 provided on the support member 52.

[0124] According to the omnidirectional wheel 12O of the thirteenth modified example, the protruding member 87 can be used to traverse steps in addition to the protruding portion 61A, so that the ability to traverse steps can be further improved.

[0125] When the protruding member 87 is provided on the support member 52 on the side from which the cable 55 is pulled out, it is important to prevent interference between the cable 55 and the protruding member 87. In such a case, it is preferable that the support member 52 be provided with a separate member that supports the pulled-out cable 55 while fixing it therein.

[0126] 30 is a cross-sectional view showing a wheel unit 64 of an omnidirectional wheel 12P according to a fourteenth modification. As shown in Fig. 30, the spherical wheel 71 may be attached to the bearing 74 and the support member 73 without the use of a sealing member 76, screws, or the like.

[0127] Specifically, the spherical annular wheel 71 is made of a flexible resin material such as a rubber-based resin, contains the bearing 74 and the support member 73, and is fitted with the bearing 74 and the support member 73. For example, the spherical annular wheel 71 may have a bottom opening 71C that is smaller than the size of the bearing 74 and the support member 73, and the bottom opening 71C may be expanded using the elasticity of the rubber-based resin to contain the bearing 74 and the support member 73. In such a case, after the bearing 74 and the support member 73 are contained, the size of the bottom opening 71C becomes smaller than the size of the bearing 74 and the support member 73. Therefore, the elasticity of the rubber-based resin allows the spherical annular wheel 71 to be attached to the bearing 74 and the support member 73 without coming off from them.

[0128] According to the omnidirectional wheel 12P of the fourteenth modified example, the installation of the spherical wheel 71 is simplified, thereby reducing the number of parts of the wheel unit 64, thereby further improving maintainability.

[0129] 31 is a perspective view partially illustrating an omnidirectional wheel 12Q according to a fifteenth modification. As shown in FIG. 31, a triangular member 88 may be further provided on the side of the rotating frame 61.

[0130] The triangular member 88 has a triangular shape and is provided on a side surface of the rotating frame 61 between the protruding portions 61A with its apex facing in the axial direction of the first rotation axis of the rotating frame 61. The triangular member 88 is also provided between the wheel unit 64 and the rotating frame 61 so as to protrude from below the wheel unit 64. In this way, the triangular member 88 can brush off dust and the like adhering to the spherical annular wheel 71 when the spherical annular wheel 71 of the wheel unit 64 passively rotates.

[0131] According to the omnidirectional wheel 12Q of the fifteenth modified example, dirt adhering to the spherical wheel 71 can be automatically removed as the spherical wheel 71 rotates, making it easier to maintain omnidirectional running performance.

[0132] 4. Application Examples (First Application Example) A first application example of the omnidirectional wheel 12 according to this embodiment will be described with reference to Fig. 32. Fig. 32 is a bottom view schematically showing the bottom of a moving body 501 to which the omnidirectional wheel 12 according to this embodiment is applied.

[0133] 32, the vehicle 501 has a circular bottom surface 511. Three omnidirectional wheels 12 are arranged along the outer periphery of the bottom surface 511 at intervals of 120 degrees from each other. The omnidirectional wheels 12 may be any of the omnidirectional wheels 12 described above.

[0134] The first rotation axes of the rotating frames 61 of the omni-directional wheels 12 may face in different directions. Specifically, the first rotation axes of the rotating frames 61 of the omni-directional wheels 12 may face in directions that differ by 120 degrees from each other.

[0135] The moving body 501 is provided with at least three omnidirectional wheels 12 with first rotation axes in different directions, and is therefore capable of moving in all directions without tipping over even when stationary.

[0136] However, in a mobile body 501 equipped with three omnidirectional wheels 12, the step-climbing ability may be significantly reduced depending on how the step S is climbed. Below, the reduction in step-climbing ability of the mobile body 501 shown in Fig. 32 will be described first with reference to Fig. 33 and Fig. 34. Fig. 33 and Fig. 34 are top views showing an example of how the mobile body 501 shown in Fig. 32 climbs the step S.

[0137] 33 , for example, when a mobile object 501 approaches a step S with one omnidirectional wheel 12 positioned in front, the traveling direction F of the mobile object 501 is the axial direction of the first rotation axis of the rotating frame 61 of the one omnidirectional wheel 12 positioned in front. In such a case, the rotating frame 61 of the one omnidirectional wheel 12 positioned in front does not rotate, and therefore the mobile object 501 cannot hook the protrusion 61A of the one omnidirectional wheel 12 positioned in front onto the step S, making it difficult to traverse the step S using the protrusion 61A.

[0138] 34 , for example, when a mobile object 501 approaches a step S with two omnidirectional wheels 12 arranged in front, the traveling direction F of the mobile object 501 is the axial direction of the first rotation axis of the rotating frame 61 of the omnidirectional wheel 12 arranged in the rear (S11). In such a case, the mobile object 501 can hook the protrusions 61A of the two omnidirectional wheels 12 arranged in the front onto the step S, but it becomes difficult to hook the protrusion 61A of the omnidirectional wheel 12 arranged in the rear onto the step S (S12). Therefore, while the mobile object 501 can traverse the step S with the two omnidirectional wheels 12 arranged in the front, it becomes difficult to make the omnidirectional wheel 12 arranged in the rear traverse the step S.

[0139] A mobile object 501 equipped with three omnidirectional wheels 12 can climb a step S using the protrusion 61A by performing the first to third actions shown in Figures 35 to 37. A method of climbing a step S that improves the step-climbing ability of the mobile object 501 shown in Figure 32 will be described with reference to Figures 35 to 37. Figures 35 to 37 are top views showing other examples of how the mobile object 501 shown in Figure 32 climbs a step S.

[0140] Specifically, in the first operation, as shown in FIG. 35 , the mobile object 501 first approaches a step S with two omnidirectional wheels 12 positioned in front of it (S21). After reaching the step S, the mobile object 501 hooks the protrusions 61A of the two omnidirectional wheels 12 positioned in front onto the step S, causing the two omnidirectional wheels 12 to traverse the step S (S22). Next, the mobile object 501 turns left or right (turns right in FIG. 35 ), tilting the one omnidirectional wheel 12 positioned in the rear to contact the step S (S23). This allows the mobile object 501 to rotate the rotating frame 61 of the one omnidirectional wheel 12 positioned in the rear, thereby hooking the protrusion 61A onto the step S and causing the one omnidirectional wheel 12 positioned in the rear to traverse the step S (S24).

[0141] In the second operation, as shown in Fig. 36 , the mobile object 501 first approaches a step S with two omnidirectional wheels 12 positioned in front (S31). After reaching the step S, the mobile object 501 hooks the protrusions 61A of the two omnidirectional wheels 12 positioned in front onto the step S, causing the two omnidirectional wheels 12 positioned in front to traverse the step S (S32). Next, the mobile object 501 turns left or right (turns right in Fig. 36 ), thereby lowering one of the omnidirectional wheels 12 that has traversed the step S below the step S (S33). After that, the mobile object 501 brings the two omnidirectional wheels 12 at the bottom of the step S into contact with the step S (S34). As a result, the mobile object 501 can hook the protrusions 61A of the two omnidirectional wheels 12 under the step S onto the step S, causing the two omnidirectional wheels 12 under the step S to traverse the step S (S35). In the second operation, the mobile object 501 can always traverse the step S with the protrusions 61A of the two omnidirectional wheels 12 hooked onto the step S, thereby suppressing slippage when traversing the step S and improving stability when traversing the step S.

[0142] Furthermore, in the third operation, as shown in FIG. 37 , the mobile object 501 first approaches the step S with the two omnidirectional wheels 12 positioned in front (S41). After reaching the step S, the mobile object 501 turns left or right (turns right in FIG. 37 ) and hooks the protrusion 61A of one of the two omnidirectional wheels 12 positioned in front onto the step S, causing one of the two omnidirectional wheels 12 positioned in front to traverse the step S (S42). Next, the mobile object 501 continues turning, causing the two omnidirectional wheels 12 below the step S to come into contact with the step S (S43). In this way, the mobile object 501 can hook the protrusions 61A of the two omnidirectional wheels 12 below the step S onto the step S, causing the two omnidirectional wheels 12 below the step S to traverse the step S (S44). In the third operation, the mobile object 501 first traverses the step S with one omnidirectional wheel 12, and then hooks the protrusions 61A of the two omnidirectional wheels 12 onto the step S to traverse the step S. This allows the mobile object 501 to traverse the step S more reliably, thereby improving the stability of traversing the step S.

[0143] (Second Application Example) A second application example of the omnidirectional wheel 12 according to this embodiment will be described with reference to Fig. 38. Fig. 38 is a perspective view showing the appearance of a moving body 601 to which the omnidirectional wheel 12 according to this embodiment is applied.

[0144] As shown in FIG. 38, the moving body 601 comprises a body 611, a left front leg 612FL, a middle front leg 612FM, a right front leg 612FR, a left hind leg 612HL, a middle hind leg 612HM, and a right hind leg 612HR.

[0145] The body 611 has a shape close to a rectangular parallelepiped. Three front legs, a left front leg 612FL, a middle front leg 612FM, and a right front leg 612FR, are arranged side by side in front of the body 611. Three hind legs, a left hind leg 612HL, a middle hind leg 612HM, and a right hind leg 612HR, are arranged side by side in rear of the body 611.

[0146] The left front leg 612FL is connected to the fuselage 611 near the front end of the left side surface thereof so as to be rotatable in the pitch direction (up and down direction) around a shaft 621FL extending laterally. The left front leg 612FL is extendable and retractable as indicated by an arrow 622FL. A left front wheel 613FL is provided at the tip of the left front leg 612FL.

[0147] The middle front leg 612FM is connected to the front of the fuselage 611 near the center thereof so as to be rotatable in the pitch direction around a shaft 621FM extending laterally. The middle front leg 612FM is extendable and retractable as indicated by an arrow 622FM. A middle front wheel 613FM is provided at the tip of the middle front leg 612FM.

[0148] The right front leg 612FR is connected to the fuselage 611 near the front end of the right side of the fuselage 611 so as to be rotatable in the pitch direction around a shaft 621FR extending laterally. The right front leg 612FR is extendable and retractable as indicated by arrow 622FR. A right front wheel 613FR is provided at the tip of the right front leg 612FR.

[0149] The left rear leg 612HL is connected to the left side of the fuselage 611 near the rear end thereof so as to be rotatable in the pitch direction around a shaft 621HL extending laterally. The left rear leg 612HL is extendable and retractable as indicated by an arrow 622HL. A left rear wheel 613HL is provided at the tip of the left rear leg 612HL.

[0150] The central rear leg 612HM is connected to the rear of the fuselage 611 near the center thereof so as to be rotatable in the pitch direction around a shaft 621HM extending laterally. The central rear leg 612HM is extendable and retractable as indicated by an arrow 622HM. A central rear wheel 613HM is provided at the tip of the central rear leg 612HM.

[0151] The right rear leg 612HR is connected to the fuselage 611 near the rear end of the right side of the fuselage 611 so as to be rotatable in the pitch direction around a shaft 621HR extending laterally. The right rear leg 612HR is extendable and retractable as shown by arrow 622HR. A right rear wheel 613HR is provided at the tip of the right rear leg 612HR.

[0152] Hereinafter, when there is no need to distinguish between the left front leg 612FL, the middle front leg 612FM, the right front leg 612FR, the left hind leg 612HL, the middle hind leg 612HM, and the right hind leg 612HR, they will be simply referred to as legs 612. Hereinafter, when there is no need to distinguish between the left front wheel 613FL, the middle front wheel 613FM, the right front wheel 613FR, the left rear wheel 613HL, the middle rear wheel 613HM, and the right rear wheel 613HR, they will be simply referred to as wheels 613.

[0153] For example, any of the above-described omnidirectional wheels 12 can be applied to one or more of the wheels 613. In other words, the omnidirectional wheel 12 can be applied to one or more of the legs 612 of the moving body 601. This improves the turning performance of the moving body 601.

[0154] As an example, the above-described omnidirectional wheels 12 may be applied to the left front wheel 613FL, the right front wheel 613FR, the left rear wheel 613HL, and the right rear wheel 613HR, which are arranged at the four corners of the moving body 601. In such a case, the middle front wheel 613FM and the middle rear wheel 613HM do not necessarily have to be omnidirectional wheels.

[0155] As another example, drive wheels that rotate in the pitch direction may be applied to the left front wheel 613FL, right front wheel 613FR, left rear wheel 613HL, and right rear wheel 613HR, which are located at the four corners of the moving body 601, and the above-mentioned omnidirectional wheels 12 may be applied to the middle front wheel 613FM and middle rear wheel 613HM.

[0156] (Other Application Examples) For example, the above-described omnidirectional wheel 12 can be applied to mobile objects in general.

[0157] By applying the omnidirectional wheels 12 to a moving body, the mobility of the moving body is improved, and the moving body can move in any direction compactly without turning. Furthermore, by applying the omnidirectional wheels 12 to a moving body, the moving body vibrates less, and therefore the moving body can suppress loosening of screws, improve the comfort of users riding on the moving body, and suppress damage to objects held or transported by the moving body.

[0158] Furthermore, by applying the omnidirectional wheels 12 to the mobile body, the mobile body can improve its ability to traverse steps compared to when a mecanum wheel, omniwheel, or omniball is used. Also, since the omnidirectional wheels 12 have a larger contact area with the ground than a mecanum wheel or omniwheel, they have high impact resistance and can reduce damage to the ground.

[0159] The in-wheel motor type omnidirectional wheel 12 can be more easily installed or wired to a moving body.

[0160] A specific example of a moving body to which the omnidirectional wheel 12 is applied will be described below.

[0161] For example, the omnidirectional wheels 12 are applied to a four-legged robot that can move in all directions, thereby improving the impact resistance of the four-legged robot.

[0162] For example, the omnidirectional wheels 12 are applied to a mobile manipulator, which is equipped with a camera and performs operations of holding objects with its hands, and therefore the low vibration characteristics of the omnidirectional wheels 12 are useful.

[0163] For example, the omnidirectional wheels 12 are applied to a filming dolly. The low vibration properties of the omnidirectional wheels 12 are useful for filming dollies to suppress camera shake and the like. Also, since filming dollies move in all directions to accommodate various filming scenes, the mobility of the omnidirectional wheels 12 is useful. Furthermore, since filming dollies are expected to move over uneven areas such as wiring and to get caught on objects dropped by performers, the ability of the omnidirectional wheels 12 to traverse uneven areas is useful.

[0164] For example, the omnidirectional wheels 12 are applied to medical carts. Because medical carts transport precision machinery, the low vibration properties of the omnidirectional wheels 12 are useful. Also, operating rooms in which medical carts are used are small, and it is expected that the medical carts will move in various directions, so the maneuverability of the omnidirectional wheels 12 is useful. In operating rooms in which medical carts are used, there are many wires on the floor, so the ability of the omnidirectional wheels 12 to traverse steps is useful.

[0165] For example, the omnidirectional wheels 12 are applied to a harvesting robot that harvests and transports agricultural crops. In the harvesting robot, the low vibration property of the omnidirectional wheels 12 is useful to prevent damage to the harvested crops. When the field where the harvesting robot is used is narrow, the maneuverability of the omnidirectional wheels 12 is useful.

[0166] For example, the omnidirectional wheel 12 may be applied to any vehicle in which a user rides, thereby improving the user's comfort, the vehicle's maneuverability, and the vehicle's ability to traverse obstacles, as well as improving the vehicle's impact resistance. For example, the omnidirectional wheel 12 may be applied to a golf cart or the like.

[0167] For example, the omnidirectional wheels 12 are applied to entertainment robots. In entertainment robots, the low vibration properties of the omnidirectional wheels 12 are useful for preventing loosening of screws, etc. Also, by arranging the omnidirectional wheels 12 in three directions, it is possible to reduce the cost, weight, and size of the entertainment robot.

[0168] For example, the omnidirectional wheels 12 are applied to a transport robot in a warehouse. In the transport robot, the low vibration property of the omnidirectional wheels 12 is useful for protecting products during transport. Furthermore, the maneuverability of the omnidirectional wheels 12 is useful in a warehouse where narrow aisles exist.

[0169] For example, the omnidirectional wheels 12 are applied to a surveying robot. Since a surveying robot that scans a space is required to be able to move freely in various directions with low vibration, the low vibration properties and maneuverability of the omnidirectional wheels 12 are useful.

[0170] For example, the omnidirectional wheels 12 are applied to a robot for sales or transportation in a store. In a robot for sales or transportation in a store, the low vibration property of the omnidirectional wheels 12 is useful for protecting merchandise being sold or transported. This allows the robot for sales or transportation to move around a narrow store without turning.

[0171] For example, the omnidirectional wheels 12 are applied to a human and baggage transport robot for rescue and other purposes. This allows the human and baggage transport robot to suppress the transmission of vibrations to the person being transported. In addition, the human and baggage transport robot can move across various terrains.

[0172] For example, the omnidirectional wheels 12 are applied to a care robot. When holding the hand of a care recipient and guiding the care recipient to walk, the care recipient is likely to feel resistance if the vibration is large. Therefore, the low vibration property of the omnidirectional wheels 12 is useful for a care robot. Furthermore, the step-crossing ability of the omnidirectional wheels 12 is useful for preventing the care robot from getting caught on wiring or fallen objects and falling over.

[0173] 5. Supplementary Notes Although preferred embodiments of the present disclosure have been described in detail above with reference to the accompanying drawings, the technical scope of the present disclosure is not limited to such examples. It is clear that a person skilled in the art of the present disclosure can conceive of various modified or altered examples within the scope of the technical idea described in the claims, and it is understood that these also naturally fall within the technical scope of the present disclosure.

[0174] For example, among the techniques according to the present disclosure, the technique relating to the protrusion 61A that enables the vehicle to traverse higher steps S can be applied to, for example, an omni-wheel.

[0175] The omni-wheel will be described with reference to Figures 39 to 41. Figures 39 to 41 are perspective views showing an example of the omni-wheel 13.

[0176] For example, as shown in FIGS. 39 to 41 , an omni-wheel 13 is a wheel in which a plurality of barrel-shaped auxiliary wheels 92 are provided around the outer periphery of a circular main wheel 91. The omni-wheel 13 can achieve multi-directional movement by actively rotating the main wheel 91 using a motor and passively rotating the auxiliary wheels 92. Specifically, the omni-wheel 13 can move in a direction perpendicular to the rotation axis of the main wheel 91 by actively rotating the main wheel 91. Furthermore, the omni-wheel 13 can move in a direction parallel to or oblique to the rotation axis of the main wheel 91 by rotating the auxiliary wheels 92 in response to the rotation of the main wheel 91 of another omni-wheel 13. The omni-wheel 13 can be used in a set of, for example, three or four wheels.

[0177] The omniwheel 13 may be a wheel in which a plurality of auxiliary wheels 92 are provided along the outer periphery of one main wheel 91, as shown in Figure 39, or a wheel in which a plurality of auxiliary wheels 92 are provided along the outer periphery of two main wheels 91 attached to each other in the direction of the rotation axis, as shown in Figures 40 and 41. The number of auxiliary wheels 92 provided along the outer periphery of the main wheel 91 may be 4, 6, or 9, and is not particularly limited as long as it is plural.

[0178] An omni-wheel 14 to which the technology according to the present disclosure is applied will be described with reference to Figures 42 to 45. Figure 42 is a front view showing the configuration of an omni-wheel 14 to which the technology according to the present disclosure is applied. Figures 43 to 45 are side views showing variations of the protrusion 93A of an omni-wheel 14 to which the technology according to the present disclosure is applied. Figure 46 is a top view showing an example of the configuration of a moving body 1A equipped with an omni-wheel 14.

[0179] 42 to 44 , an omni-wheel 14 to which the technology according to the present disclosure is applied is provided with a frame 93 that protrudes from the side of a main wheel 91 in the direction of the rotation axis of the main wheel 91. The frame 93 is provided with at least one or more protrusions 93A that protrude in the radial direction of the main wheel 91. This allows the omni-wheel 14 to rotate the frame 93 and the protrusions 93A around the rotation axis of the main wheel 91 as the main wheel 91 rotates. Therefore, similar to the omni-directional wheel 12 according to the above embodiment, the omni-wheel 14 can traverse a step S by hooking the protrusions 93A onto the step S.

[0180] In FIGS. 42 to 44, three protrusions 93A protrude from the frame 93, but the number of protrusions 93A is not particularly limited as long as it is at least one.

[0181] The planar shape of the frame 93 cut along a plane perpendicular to the rotation axis of the main body wheels 91 may be any of a circle, a polygon, and a rounded polygon. The frame 93 and the protrusion 93A may be integrated with each other as shown in Fig. 44. In such a case, the planar shape of the frame 93 and the protrusion 93A cut along a plane perpendicular to the rotation axis of the main body wheels 91 may be a polygon or a rounded polygon.

[0182] Furthermore, as shown in Figure 45, the omni-wheel 14 may not have a frame 93, but may have at least one or more protrusions 93A protruding from the side of the main wheel 91 in the direction of the rotation axis of the main wheel 91. Even in such a case, the omni-wheel 14 can traverse a step S by hooking the protrusion 93A onto the step S, just like the omni-directional wheel 12 according to the above embodiment. However, in order to traverse the step S, it is important for the omni-wheel 14 to hook the protrusion 93A onto the step S and then move the auxiliary wheel 92 onto the top surface of the step S. Therefore, in order to smoothly move the auxiliary wheel 92 onto the top surface of the step S, it is desirable that the protrusion 93A be provided, for example, near the auxiliary wheel 92.

[0183] The frame 93 and the protrusion 93A may protrude from one side surface of the main wheel 91, or may protrude from both side surfaces of the main wheel 91. When the frame 93 and the protrusion 93A protrude from both side surfaces of the main wheel 91, the omniwheel 14 can improve its ability to traverse steps evenly in all directions, front to back, left to right.

[0184] On the other hand, when the frame 93 and the protrusion 93A protrude from only one side of the main wheel 91, the omni-wheel 14 can improve its ability to traverse steps in a specific direction depending on how it is attached to the moving body.

[0185] As shown in FIG. 46 , when improving the step-neighboring ability in the traveling direction F, the omni-wheels 14 are attached to the main body 11 of the mobile body 1A so that the frame 93 and protrusion 93A protrude toward the traveling direction F. For example, each omni-wheel 14 is arranged so as to intersect obliquely with the traveling direction F. In an omni-wheel 14 arranged on the front side with respect to the traveling direction F, the frame 93 and protrusion 93A are arranged to protrude outward from the mobile body 1A so as to protrude further toward the traveling direction F. In an omni-wheel 14 arranged on the rear side with respect to the traveling direction F, the frame 93 and protrusion 93A are arranged to protrude inward from the mobile body 1A so as to protrude further toward the traveling direction F. This makes it easier for the protrusion 93A of the mobile body 1A to hook onto steps S present in the traveling direction F, thereby further improving the step-neighboring ability in the traveling direction F.

[0186] The omni-wheel 14 can be attached to the main body 11 using the support member 52 in the same manner as in the above embodiment.

[0187] Furthermore, the effects described herein are merely descriptive or exemplary and are not limiting. In other words, the technology according to the present disclosure may achieve other effects that will be apparent to those skilled in the art from the description of this specification, in addition to or in place of the above-described effects.

[0188] Note that the following configurations also fall within the technical scope of the present disclosure. (1) A wheel structure comprising: a rotating frame rotatable about a first rotation axis and extending in the axial direction of the first rotation axis; three or more wheel units each provided on approximately the same circumference of a side surface of the rotating frame, each having a contact surface that constitutes a part of the spherical surface of an imaginary sphere, and rotatable about a second rotation axis perpendicular to the first rotation axis; and at least one or more protrusions provided to protrude from a side surface of the rotating frame extending from at least one side of the wheel units and extending in the axial direction of the first rotation axis. (2) The wheel structure described in (1) above, in which the wheel units are provided on the side surface of the rotating frame in rotational symmetry when viewed in the axial direction of the first rotation axis. (3) The wheel structure described in (1) above, in which a plurality of the protrusions are provided, and are provided on the side surface of the rotating frame in rotational symmetry when viewed in the axial direction of the first rotation axis. (4) The wheel structure according to (3), wherein the number of the protrusions is the same as the number of the wheel units, and the protrusions are provided between the wheel units when viewed in the axial direction of the first rotation shaft. (5) The wheel structure according to (1), wherein the protrusions are provided on each side surface of the rotating frame extending from both sides of the wheel units. (6) The wheel structure according to (1), wherein the friction coefficient of at least a part of the protrusions is higher than the friction coefficient of the rotating frame. (7) The wheel structure according to (6), wherein the end of the protrusion opposite to the side on which the wheel units are provided is made of a rubber member. (8) The wheel structure according to (7), wherein the rubber member is provided so as to be freely rotatable about an axis parallel to the first rotation shaft. (9) The wheel structure according to (1), wherein the upper surface of the protrusion in the protruding direction is provided with a recess extending in the rotation direction of the first rotation shaft. (10) The wheel structure according to (1), further comprising an auxiliary wheel provided inside the wheel unit so as to expose the ground contact surface from an opening provided at the top of the wheel unit, and rotatable about a third rotation axis perpendicular to both the first rotation axis and the second rotation axis. (11) The wheel structure according to (1), further comprising a drive unit provided inside the rotating frame and rotating the rotating frame about the first rotation axis.(12) The wheel structure according to (11), further comprising a sensor unit including at least one of an acceleration sensor that measures acceleration applied to the wheel structure and a current sensor that measures current flowing in the drive unit. (13) The wheel structure according to (1), further comprising a pair of support members that sandwich the rotating frame from the axial direction of the first rotating shaft. (14) The wheel structure according to (13), wherein the support members are provided with openings that allow access to the outer periphery of the rotating frame. (15) The wheel structure according to (13), wherein the support members are provided with a tapered planar shape that narrows toward the connection point with the rotating frame when viewed from above from the axial direction of the first rotating shaft. (16) The wheel structure according to (15), wherein a recessed structure that is recessed toward the inside of the planar shape is further provided midway along the slope of the taper. (17) The wheel structure according to (1), wherein an alert member is further provided on a side surface of the protrusion in the axial direction of the first rotation shaft, or on an upper surface or side surface of the protrusion in the protruding direction. (18) The wheel structure according to (17), wherein the alert member is a phosphorescent material or a reflective material. (19) The wheel structure according to (1), wherein a protective part having a spherical shape with a radius smaller than the radius of the imaginary sphere is further provided between the rotating frame and the wheel unit. (20) A moving body having at least three or more wheel structures, each of the wheel structures being rotatable around a first rotation axis and extending in the axial direction of the first rotation axis; three or more wheel units each provided on approximately the same circumference on a side surface of the rotation frame, each having a contact surface that forms a part of the spherical surface of an imaginary sphere, and rotatable around a second rotation axis that is perpendicular to the first rotation axis; and at least one or more protrusions provided on a side surface of the rotation frame extending from at least one side of the wheel unit and extending in the axial direction of the first rotation axis.

[0189] REFERENCE SIGNS LIST 1 Mobile body 11 Main body 12 Omnidirectional wheel 52 Support member 53 Bearing 55 Cable 61 Rotating frame 61A Protrusion 62 First frame 63 Second frame 71 Spherical annular wheel 72 Auxiliary wheel 73 Support member 74 Bearing 75 Bearing 76 Sealing member 111 Output shaft 112 Drive unit 123 Encoder

Claims

1. A wheel structure comprising: a rotating frame rotatable about a first rotation axis and extending in the axial direction of the first rotation axis; three or more wheel units each provided on approximately the same circumference on the side of the rotating frame, each having a contact surface that constitutes a portion of the spherical surface of an imaginary sphere, and rotatable about a second rotation axis that is perpendicular to the first rotation axis; and at least one or more protrusions provided on the side of the rotating frame extending from at least one side of the wheel units and extending in the axial direction of the first rotation axis.

2. A wheel structure as set forth in claim 1, wherein the wheel units are provided on the side surfaces of the rotating frame in rotational symmetry when viewed in the axial direction of the first rotating shaft.

3. A wheel structure as described in claim 1, wherein a plurality of the protrusions are provided on the side surface of the rotating frame, and are rotationally symmetrical when viewed from the axial direction of the first rotating shaft.

4. A wheel structure as described in claim 3, wherein the number of said protrusions is the same as the number of said wheel units, and said protrusions are provided between said wheel units when viewed in the axial direction of said first rotation shaft.

5. The wheel structure according to claim 1, wherein the protrusions are provided on the sides of the rotating frame extending from both sides of the wheel unit.

6. The wheel structure of claim 1, wherein the coefficient of friction of at least some of the protrusions is higher than the coefficient of friction of the rotating frame.

7. A wheel structure according to claim 6, wherein the end of the protrusion opposite to the side on which the wheel unit is provided is made of a rubber material.

8. A wheel structure according to claim 7, wherein the rubber member is provided so as to be freely rotatable about an axis parallel to the first rotation axis.

9. A wheel structure as set forth in claim 1, wherein a recess extending in the rotation direction of the first rotation shaft is provided on the upper surface of the protruding portion in the protruding direction.

10. The wheel structure described in claim 1, further comprising an auxiliary wheel provided inside the wheel unit so that the ground contact surface is exposed from an opening provided at the top of the wheel unit, and rotatable around a third rotation axis perpendicular to both the first rotation axis and the second rotation axis.

11. The wheel structure according to claim 1, further comprising a drive unit provided inside the rotating frame for rotating the rotating frame about the first rotation axis.

12. The wheel structure according to claim 11, further comprising a sensor unit including at least one of an acceleration sensor that measures acceleration applied to the wheel structure, or a current sensor that measures current flowing in the drive unit.

13. The wheel structure according to claim 1, further comprising a pair of support members that sandwich the rotating frame in the axial direction of the first rotating shaft.

14. The wheel structure of claim 13, wherein the support member is provided with an opening that provides access to the outer periphery of the rotating frame.

15. A wheel structure as described in claim 13, wherein the support member has a tapered planar shape that narrows toward the connection point with the rotating frame when viewed in a plan view from the axial direction of the first rotating shaft.

16. The wheel structure according to claim 15, wherein a recessed structure recessed toward the inside of the planar shape is further provided midway along the inclination of the taper.

17. The wheel structure according to claim 1, further comprising an alert member provided on a side surface of the protrusion in the axial direction of the first rotation shaft, or on an upper surface or side surface of the protrusion in the protruding direction.

18. The wheel structure according to claim 17, wherein the alert member is a luminous member or a reflective member.

19. The wheel structure according to claim 1, further comprising a protective portion having a spherical shape with a radius smaller than the radius of the imaginary sphere, provided between the rotating frame and the wheel unit.

20. A mobile body comprising at least three or more wheel structures, each of which is rotatable around a first rotation axis and extends in the axial direction of the first rotation axis; three or more wheel units each provided on approximately the same circumference on the side of the rotation frame, each having a contact surface that forms a part of the spherical surface of an imaginary sphere, and rotatable around a second rotation axis that is perpendicular to the first rotation axis; and at least one or more protrusions provided on the side of the rotation frame extending from at least one side of the wheel unit and extending in the axial direction of the first rotation axis.

Images