Drive control device, drive device, wheel and vehicle

Abstract

To maintain a speed difference of rotation speed among a plurality of motors with high accuracy.SOLUTION: A drive control device includes: a command value output part for outputting a first command value to a first motor for rotating a first rotation object, and outputting a second command value to a second motor for rotating a second rotation object different from the first rotation object; a calculation part for calculating a first speed deviation that is a difference between the first command value and first rotation speed that is rotation speed of an output shaft of the first motor operated on the basis of the first command value, and a second speed deviation that is a difference between the second command value and second rotation speed that is rotation speed of an output shaft of the second motor operated on the basis of the second command value; and a correction part for calculating a reference value on the basis of the first speed deviation and the second speed deviation, and correcting the second command value using the calculated reference value.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present disclosure relates to a drive control device, a drive unit, a wheel, and a vehicle. [Background technology]

[0002] There are known drive control device configurations that synchronously control multiple motors. For example, Patent Document 1 describes a drive control device that controls multiple motors so that when the same rotation speed command value is input to each motor, the output value of each motor is the same. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2010-178510 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the drive control device described in Patent Document 1 is not configured to control a plurality of motors so as to maintain the difference in rotation speed when different rotation speed command values are input to the motors.

[0005] The present disclosure has been made in consideration of the above, and aims to provide a drive control device, a drive device, a wheel, and a vehicle that are capable of maintaining the speed difference in rotational speed between multiple motors with high precision. [Means for solving the problem]

[0006] A drive control device according to one embodiment of the present disclosure includes: a command value output unit that outputs a first command value to a first motor that rotates a first rotating object, and outputs a second command value to a second motor that rotates a second rotating object different from the first rotating object; and a calculation unit that calculates a first speed error that is the difference between the first command value and a first rotational speed that is the rotational speed of an output shaft of the first motor when the first command value is input, and a second speed error that is the difference between the second command value and a second rotational speed that is the rotational speed of an output shaft of the second motor when the second command value is input, calculates a reference value based on the first speed error and the second speed error, and corrects the second command value input to the second motor using the reference value.

[0007] With this configuration, a reference value is calculated based on the speed deviation of the rotational speed of the first motor and the speed deviation of the rotational speed of the second motor, and the second command value of the second motor is corrected based on the calculated reference value. Therefore, even when the motor is affected by, for example, a disturbance, the second command value is corrected in accordance with the disturbance, making it possible to accurately maintain the speed difference between the first rotational speed of the first motor and the second rotational speed of the second motor.

[0008] In the drive control device, the output shaft of the first motor is connected to the first rotating object via a first reducer having a first reduction ratio, and the output shaft of the second motor is connected to the second rotating object via a second reducer having a second reduction ratio. The calculator calculates the difference between the first speed deviation multiplied by the first value and the second speed deviation multiplied by the second value, and then divides the calculated difference by the second value to obtain the reference value. With this configuration, when the output shaft of the first motor and the output shaft of the second motor are connected to the first rotating object and the second rotating object via the first reducer and the second reducer, respectively, the reduction ratios of the first reducer and the second reducer can be reflected in the reference value. This enables the second command value to be corrected with high accuracy.

[0009] In the drive control device, the calculation unit corrects the second command value by adding the reference value to the second command value output from the command value output unit. This configuration makes it possible to correct the second command value with high accuracy.

[0010] A drive device according to one embodiment of the present disclosure includes a drive control device having: a first motor that rotates a first rotating object; a second motor that rotates a second rotating object different from the first rotating object; a command value output unit that outputs a first command value to the first motor and a second command value to the second motor; and a calculation unit that calculates a first speed error that is the difference between the first command value and a first rotational speed that is the rotational speed of an output shaft of the first motor when the first command value is input, and a second speed error that is the difference between the second command value and a second rotational speed that is the rotational speed of an output shaft of the second motor when the second command value is input, calculates a reference value based on the first speed error and the second speed error, and corrects the second command value input to the second motor using the reference value.

[0011] This configuration makes it possible to provide a drive device that can maintain the difference between the first rotation speed of the first motor and the second rotation speed of the second motor with high precision.

[0012] In the above drive device, the torque generated by the second motor to rotate the second rotating object is smaller than the torque generated by the first motor to rotate the first rotating object. With this configuration, the second command value of the second motor, which generates a smaller torque, is corrected, allowing for more accurate correction than when correcting the first motor.

[0013] A wheel according to one embodiment of the present disclosure comprises a wheel body that rotates around an axle by a first motor, an arm that is supported on the wheel body so as to be rotatable around an arm rotation axis parallel to the wheel body and that rotates between a retracted position and an extended position by a second motor in accordance with the rotation of the wheel body, a command value output unit that outputs a first command value to the first motor and a second command value to the second motor, and a calculation unit that calculates a first speed deviation that is the difference between the first command value and a first rotation speed that is the rotation speed of an output shaft of the first motor when the first command value is input, and a second speed deviation that is the difference between the second command value and a second rotation speed that is the rotation speed of an output shaft of the second motor when the second command value is input, calculates a reference value based on the first speed deviation and the second speed deviation, and corrects the second command value input to the second motor using the reference value.

[0014] With this configuration, even when at least one of the wheel body and the arm is affected by external disturbances, etc., the speed difference in rotational speed between the first motor and the second motor can be maintained with high precision, thereby maintaining stability during rotation.

[0015] A wheel according to one embodiment of the present disclosure comprises a drive control device having: a wheel body rotatable about an axle by a first motor and a second motor, and rotatable about a pivot axis perpendicular to the axle in accordance with a speed difference between the rotational speed of the first motor and the rotational speed of the second motor; a command value output unit that outputs a first command value to the first motor and a second command value to the second motor; and a calculation unit that calculates a first speed deviation that is the difference between the first command value and a first rotational speed that is the rotational speed of an output shaft of the first motor when the first command value is input, and a second speed deviation that is the difference between the second command value and a second rotational speed that is the rotational speed of an output shaft of the second motor when the second command value is input, calculates a reference value based on the first speed deviation and the second speed deviation, and corrects the second command value input to the second motor using the reference value.

[0016] With this configuration, even when the wheel body is affected by external disturbances, etc., the speed difference in rotational speed between the first motor and the second motor can be maintained with high precision, thereby maintaining stability during rotation and cornering.

[0017] A vehicle according to one aspect of the present disclosure includes the above-described wheel and a vehicle body that supports the wheel rotatably around the axle.

[0018] This configuration provides a vehicle that is capable of running stably, since it is equipped with wheels that can maintain stability when rotating. [Effects of the Invention]

[0019] According to the present disclosure, the speed difference between the rotational speeds of multiple motors can be maintained with high precision. [Brief explanation of the drawings]

[0020] [Figure 1] FIG. 1 is a schematic diagram showing an example of a drive device according to this embodiment. [Figure 2] FIG. 2 is a control block diagram showing an example of control content in the drive device. [Figure 3] FIG. 3 is a diagram showing an example of a wheel according to this embodiment. [Figure 4] FIG. 4 is a diagram showing the configuration along the cross section AA in FIG. [Figure 5] FIG. 5 is a diagram showing an example of a state in which the arms of the wheel are protruded. [Figure 6] FIG. 6 is a diagram schematically illustrating an example of the configuration of a vehicle equipped with wheels. [Figure 7] FIG. 7 is a diagram illustrating an example of the operation of the vehicle. [Figure 8] FIG. 8 is a diagram illustrating an example of the operation of the vehicle. [Figure 9] FIG. 9 is a diagram illustrating an example of the operation of the vehicle. [Figure 10] FIG. 10 is a diagram illustrating an example of the operation of the vehicle. [Figure 11]FIG. 11 is a diagram illustrating an example of the operation of the vehicle. [Figure 12] FIG. 12 is a diagram illustrating an example of the operation of the vehicle. [Figure 13] FIG. 13 is a diagram showing a vehicle according to another example. [Figure 14] FIG. 14 is a diagram showing an example of a driving wheel. DETAILED DESCRIPTION OF THE INVENTION

[0021] The embodiments of the present disclosure will be described in detail with reference to the drawings. The present disclosure is not limited to the contents described in the following embodiments. Furthermore, the components described below include those that can be easily imagined by a person skilled in the art and those that are substantially the same. Furthermore, the components described below can be combined as appropriate.

[0022] [Drive control device and drive device] Fig. 1 is a schematic diagram showing an example of a driving device 100 according to this embodiment. As shown in Fig. 1, the driving device 100 includes a driving source 10 and a drive control device 20. The driving source 10 includes a first motor 11, a second motor 12, a first encoder 13, and a second encoder 14.

[0023] The first motor 11 and the second motor 12 have, for example, the same configuration. In this embodiment, for example, the first motor 11 is the master side and the second motor 12 is the slave side, but this is not limiting. The first motor 11 and the second motor 12 are, for example, inner rotor motors. The first motor 11 and the second motor 12 include, for example, a stator, a rotor that rotates relative to the stator when power is supplied, and output shafts 11a and 12a that rotate together with the rotors. The first encoder 13 detects a first rotational speed N1, which is the rotational speed of the output shaft 11a of the first motor 11. The second encoder 14 detects a second rotational speed N2, which is the rotational speed of the output shaft 12a of the second motor 12.

[0024] The output shaft 11a of the first motor 11 is connected to a first rotating object 17 via a first reducer 15. The first rotating object 17 rotates or turns by the driving force of the first motor 11. The first reducer 15 is configured using, for example, multiple gears. The first reducer 15 has a reduction ratio of a first value G1.

[0025] The output shaft 12a of the second motor 12 is connected to a second rotating object 18 via a second reducer 16. The second rotating object 18 rotates or turns due to the driving force of the second motor 12. The second reducer 16 is configured using, for example, a plurality of gears. The second reducer 16 has a reduction ratio of a second value G2. For example, the second value G2 can be set to a value smaller than the first value G1, but is not limited to this.

[0026] The drive control device 20 controls the drive source 10. The drive control device 20 has a processing device such as a CPU (Central Processing Unit) and a storage device such as a RAM (Random Access Memory) or a ROM (Read Only Memory). The drive control device 20 includes a command value output unit 21 and a calculation unit 22.

[0027] FIG. 2 is a control block diagram showing an example of control details in the drive device 100. The command value output unit 21 has a first output unit 21a and a second output unit 21b. The first output unit 21a sets and outputs a first command value C1 for the first motor 11. The first output unit 21a sets the first command value C1 as a value for rotating the output shaft 15a of the first motor 11 so that a predetermined first torque is applied to the first rotating object 17. The first command value C1 is input to a driver 11b of the first motor 11. The first motor 11 rotates the output shaft 11a based on the first command value C1 input to the driver 11b. The first encoder 13 detects the rotation speed (first rotation speed N1) of the output shaft 11a.

[0028] The second output unit 21b sets and outputs a second command value C2 for the second motor 12. In this embodiment, the second output unit 21b can set the second command value C2 as a value for rotating the output shaft 16a of the second motor 12 so that a second torque smaller than the first torque is applied to the second rotating object 18. The second command value C2 is input to a driver 12b of the second motor 12. The second motor 12 rotates the output shaft 12a based on the second command value C2 input to the driver 12b. The second encoder 14 detects the rotation speed (second rotation speed N2) of the output shaft 12a.

[0029] The calculation unit 22 has speed deviation calculation units 23 and 24, multiplication value calculation units 25 and 26, a difference calculation unit 27, a reference value calculation unit 28, and a correction calculation unit 29. The calculation unit 22 calculates a first speed deviation E1 and a second speed deviation E2, calculates a reference value RN based on the first speed deviation E1 and the second speed deviation E2, and corrects a second command value C2 input to the second motor 12 using the reference value RN.

[0030] The speed deviation calculation unit 23 acquires a first command value C1 and a first rotation speed N1 of the first motor 11 when the first command value C1 is input. The speed deviation calculation unit 23 calculates a first speed deviation E1, which is the difference between the first command value C1 and the first rotation speed N1. The speed deviation calculation unit 24 acquires a second command value C2 and a second rotation speed N2 of the second motor 12 when the second command value C2 is input. The speed deviation calculation unit 24 calculates a second speed deviation E2, which is the difference between the second command value C2 and the second rotation speed N2.

[0031] The multiplication value calculation unit 25 calculates a multiplication value (E1·G1) by multiplying the first speed deviation E1 by a first value G1, which is the reduction ratio of the first reducer 15. The multiplication value calculation unit 26 calculates a multiplication value (E2·G2) by multiplying the second speed deviation E2 by a second value G2, which is the reduction ratio of the second reducer 16. The difference calculation unit 27 calculates the difference between the multiplication value (E1·G1) and the multiplication value (E2·G2). The reference value calculation unit 28 calculates a value obtained by dividing the difference by the second value G2, which is the reduction ratio of the second reducer 16, as the reference value RN. In other words, the reference value RN can be expressed by the following equation.

[0032] RN=(E1 G1 - E2 G2) / G2 =E1 G1 / G2 - E2

[0033] The correction calculation unit 29 subtracts the reference value RN from the second command value C2 input to the second motor 12. The calculation unit 22 can correct the second command value C2 by performing calculations using the multiplication value calculation unit 25, the multiplication value calculation unit 26, the difference calculation unit 27, the reference value calculation unit 28, and the correction calculation unit 29. When the second command value C2 is corrected, the corrected second command value (C2-RN) is input to the driver 12b of the second motor 12.

[0034] As described above, the drive control device 20 according to this embodiment includes a command value output unit 21 that outputs a first command value C1 to the first motor 11 that rotates the first rotating object 17 and outputs a second command value C2 to the second motor 12 that rotates the second rotating object 18 that is different from the first rotating object 17, and a calculation unit 22 that calculates a first speed error E1 that is the difference between the first command value C1 and a first rotation speed N1 that is the rotation speed of the output shaft 11a of the first motor 11 when the first command value C1 is input, and a second speed error E2 that is the difference between the second command value C2 and a second rotation speed N2 that is the rotation speed of the output shaft 12a of the second motor 12 when the second command value C2 is input, calculates a reference value RN based on the first speed error E1 and the second speed error E2, and corrects the second command value C2 input to the second motor 12 using the reference value RN.

[0035] According to this configuration, the reference value RN is calculated based on the first speed error E1 of the rotational speed of the first motor 11 and the second speed error E2 of the rotational speed of the second motor 12, and the second command value C2 of the second motor is corrected based on the calculated reference value RN. Therefore, even when there is an influence of an external disturbance, for example, the second command value C2 is corrected in accordance with the disturbance, so that the speed difference between the first rotational speed N1 of the first motor 11 and the second rotational speed N2 of the second motor 12 can be maintained with high accuracy.

[0036] In the drive control device 20 according to this embodiment, the output shaft 11a of the first motor 11 is connected to the first rotating object 17 via a first reducer 15 having a reduction ratio of a first value G1, and the output shaft 12a of the second motor 12 is connected to the second rotating object 18 via a second reducer 16 having a reduction ratio of a second value G2. The calculation unit 22 calculates the difference between the value obtained by multiplying the first speed deviation E1 by the first value G1 and the value obtained by multiplying the second speed deviation E2 by the second value G2, and then divides the calculated difference by the second value G2 to obtain the reference value RN. With this configuration, when the output shaft 11a of the first motor 11 and the output shaft 12a of the second motor 12 are connected to the first rotating object 17 and the second rotating object 18 via the first reducer 15 and the second reducer 16, respectively, the reduction ratios of the first reducer 15 and the second reducer 16 can be reflected in the reference value RN. This enables the second command value C2 to be corrected with high accuracy.

[0037] In the drive control device 20 according to this embodiment, the calculation unit 22 corrects the second command value C2 by subtracting the reference value RN from the output second command value C2. This configuration makes it possible to correct the second command value C2 with high accuracy.

[0038] The drive device 100 according to this embodiment includes a first motor 11 that rotates a first rotating object 17, a second motor 12 that rotates a second rotating object 18 that is different from the first rotating object 17, a command value output unit 21 that outputs a first command value C1 to the first motor 11 and a second command value C2 to the second motor 12, and a drive control device 20 that has a calculation unit 22 that calculates a first speed error E1, which is the difference between the first command value C1 and a first rotation speed N1, which is the rotation speed of the output shaft 11a of the first motor 11 when the first command value C1 is input, and a second speed error E2, which is the difference between the second command value C2 and a second rotation speed N2, which is the rotation speed of the output shaft 12a of the second motor 12 when the second command value C2 is input, calculates a reference value RN based on the first speed error E1 and the second speed error E2, and corrects the second command value C2 input to the second motor 12 using the reference value RN. This configuration makes it possible to provide the driving device 100 that can maintain the difference between the first rotation speed N1 of the first motor 11 and the second rotation speed N2 of the second motor 12 with high precision.

[0039] In the driving device 100 according to this embodiment, the torque used by the second motor 12 to rotate the second rotating object is smaller than the torque used by the first motor 11 to rotate the first rotating object 17. With this configuration, the second command value C2 of the second motor 12, which generates a smaller torque, is corrected, and therefore the correction can be performed more accurately than when correcting the first motor 11.

[0040] [Wheels and vehicles] Next, a wheel and a vehicle according to this embodiment will be described. FIG. 3 is a diagram showing an example of a wheel 200 according to this embodiment. FIG. 4 is a diagram showing a configuration along the AA cross section in FIG. 3. FIG. 5 is a diagram showing an example of a state in which the arm 40 of the wheel 200 is protruding. In the following description, the rotation direction when the wheel 200 rotates in a direction to travel over a step is referred to as the forward direction R1, and the rotation direction opposite to the forward direction R1 is referred to as the reverse direction R2. The traveling direction when the wheel 200 rotates in the forward direction R1 is the right direction in FIG. 3. The forward direction R1 is the clockwise direction in FIG. 3. The reverse direction R2 is the counterclockwise direction in FIG. 3. The front refers to the surface facing the traveling direction when the wheel 200 rotates in the forward direction R1, and the side refers to the surface facing the outer or inner side of the vehicle body when the wheel 200 is mounted on a self-propelled vehicle. In FIG. 4, the outer side is the left, and the inner side is the right.

[0041] 3 to 5 is a drive wheel mounted on a self-propelled vehicle such as a delivery robot, an unmanned transport vehicle, a transport cart, an electric wheelchair, a cleaning robot, or a partner robot. The self-propelled vehicle is assumed to be, for example, a four-wheel vehicle (see, for example, FIG. 6 described later) in which the wheels 200 are arranged symmetrically, but the present disclosure is not limited to this. The wheel 200 includes a wheel main body 30, an arm 40, a wheel drive unit 50, an arm drive unit 60, a support unit 70, and a drive control device 80.

[0042] The wheel main body 30 is mounted on an axle member 31. The axle member 31 is a cylindrical shaft member whose axis coincides with the axle Aw. The axle member 31 is provided rotatably around the axle Aw relative to a support part 70, which will be described later. The axle member 31 is inserted into a first through-hole 71 of the support part 70, and is supported rotatably around the axle Aw relative to the support part 70 via a bearing B1. One end of the axle member 31 in the axial direction of the axle Aw is connected to an output shaft 62 of the arm drive part 60, which will be described later. A gear 34 is fixed to the other end of the axle member 31 in the axial direction of the axle Aw.

[0043] The gear 34 is an external gear with teeth 34a formed on its outer circumferential surface. The gear 34 is fixed to the axle member 31 so that its axis coincides with the axle Aw. The teeth 34a mesh with teeth 41a formed on a base 41 of an arm 40, which will be described later. The gear 34 and the base 41 correspond to, for example, the second reducer 16 in the embodiment of the drive unit 100 described above.

[0044] The wheel body 30 is provided rotatably around the axle Aw relative to the axle member 31. In this embodiment, the wheel body 30 is provided adjacent to the outer surface 70a of the support portion 70, which will be described later. The wheel body 30 has a configuration that corresponds to the first rotation object 17 in the embodiment of the drive unit 100 described above. The wheel body 30 includes a through hole 32, an annular recess 33, an outer ring portion 35, three arm support shafts 36, three restriction portions 37, and a gear 38.

[0045] The through-hole 32 penetrates the wheel main body 30 in the direction of the axle Aw. The through-hole 32 is open at both ends in the direction of the axle Aw. An axle member 31 is inserted into the through-hole 32. The wheel main body 30 is supported in the through-hole 32 via a bearing B2 to be rotatable about the axle Aw relative to the axle member 31. The wheel main body 30 is also supported via the through-hole 32, bearing B2, axle member 31, and bearing B1 to be rotatable about the axle Aw relative to a support portion 70 described below.

[0046] The annular recess 33 is provided on a first surface 30a of the wheel body 30 that faces the support portion 70. The annular recess 33 is an annular recess formed around the axle Aw. A gear 38, which will be described later, is disposed in the annular recess 33.

[0047] The outer ring portion 35 is cylindrical with an axis coinciding with the axle Aw. The outer ring portion 35 constitutes the outer peripheral surface of the wheel body 30. The outer ring portion 35 may have an annular tire portion (not shown) attached along the circumferential direction. The tire portion is made of, for example, rubber, and absorbs impacts that the wheel body 30 receives from the contact surface during driving.

[0048] The arm support shaft 36 is a cylindrical shaft member whose axis coincides with the arm rotation axis Aa. The arm rotation axis Aa is parallel to the wheel axis Aw. In this embodiment, three arm support shafts 36 are provided for one wheel 200. Each arm support shaft 36 is provided to protrude from the second surface 30b of the wheel main body 30, which is on the reverse side of the first surface 30a. The second surface 30b is the side that faces the outside of the vehicle body when the wheel 200 is mounted on a self-propelled vehicle. The arm support shaft 36 is inserted into an arm 40 (described below) and supports the arm 40 rotatably about the arm rotation axis Aa via a bearing B3. The three arm rotation axes Aa corresponding to the three arm support shafts 36 are all equidistant from the wheel axis Aw. The three arm rotation axes Aa are also provided rotationally symmetrically and equidistantly around the wheel axis Aw. In this embodiment, three arm support shafts 36 are provided, but two or less or four or more may be provided. The arm support shafts 36 correspond to the number of arms 40 (described later) provided, and one arm support shaft 36 is provided for each arm 40.

[0049] The restricting portion 37 is a stopper member that restricts the rotation range of the arm 40 (described later) in one direction around the arm rotation axis Aa. The restricting portion 37 restricts the rotation range of the arm 40 in one direction by contacting the arm 40. The one direction is a protruding direction Rp (described later). In the embodiment, three restricting portions 37 are provided for one wheel 200. The three restricting portions 37 are provided rotationally symmetrically and at equal intervals around the wheel axis Aw. In other words, the three restricting portions 37 restrict the corresponding arm 40 to the same rotation angle. One restricting portion 37 is provided for each arm 40, corresponding to the number of arms 40 (described later).

[0050] The gear 38 is an external gear with teeth 38a formed on its outer circumferential surface. The gear 38 is fixed to the inner circumferential surface 33a of the annular recess 33 so that its axis coincides with the axle Aw. The teeth 38a mesh with teeth 53a of a gear 53 of the wheel drive unit 50 (described later). The gear 38 rotates integrally with the wheel main body 30 around the axle Aw. In this embodiment, the gear 38 directly meshes with the gear 53 and rotates in the opposite direction to the rotational direction of the gear 53, but this configuration is not limited to this. The rotation of the gear 38 may be transmitted via a gear other than the gear 53, or the gear 38 may be provided to rotate in the same direction as the rotational direction of the gear 53. The gear 38 and the gear 53 correspond to the first reducer 15 in the embodiment of the drive unit 100 described above.

[0051] In this embodiment, three arms 40 are provided for one wheel 200. The arm support shaft 36 of the wheel body 30 is inserted into each arm 40. Each arm 40 is supported by the arm support shaft 36 of the wheel body 30 so as to be rotatable around the corresponding arm rotation axis Aa. The arm 40 is rotatable around the arm rotation axis Aa between the stored position shown in FIG. 3 and the extended position shown in FIG. 5. The arm 40 has a base 41 and a claw 42. The arm 40 has a configuration corresponding to the second rotation object 18 in the embodiment of the drive device 100 described above.

[0052] The base 41 has a cylindrical portion that surrounds the arm support shaft 36, and has teeth 41a on the outer peripheral surface of the cylindrical portion. A plurality of teeth 41a are provided around the arm rotation axis Aa. The teeth 41a mesh with the teeth 34a of the gear 34 that is fixed to the axle member 31 described above. As the teeth 41a mesh with the teeth 34a of the gear 34, when the axle member 31 rotates, the base 41 rotates in the direction opposite to the rotation direction of the axle member 31. The claws 42 extend from the base 41 radially outward of the wheel body 30, and have a shape that is bent along the circumferential direction of the wheel body 30.

[0053] The arm 40 moves from the stored position to the protruding position relative to the wheel body 30 by rotating in the protruding direction Rp. The protruding direction Rp is a rotation direction around the arm rotation axis Aa and in the same direction as the reverse direction R2. In Figures 3 and 5, the protruding direction Rp is a counterclockwise direction centered on the arm rotation axis Aa. When the arm 40 is in the protruding position, the claw portion 42 protrudes radially outward from the outer periphery of the wheel body 30.

[0054] The arm 40 moves from the extended position to the stored position relative to the wheel body 30 by rotating in the storage direction Rs. The storage direction Rs is a rotation direction around the arm rotation axis Aa and in the same direction as the forward direction R1. In Figures 3 and 5, the storage direction Rs is a clockwise direction centered on the arm rotation axis Aa. When the arm 40 is in the storage position, the claw portion 42 is stored radially inward from the outer periphery of the wheel body 30.

[0055] The wheel drive unit 50 rotates the wheel body 30 around the axle Aw relative to the support unit 70, which will be described later. The wheel drive unit 50 has a first motor 51. The first motor 51 is a rotational drive source for the wheel body 30. The first motor 51 has a configuration equivalent to the first motor 11 in the embodiment of the drive device 100 described above, and is, for example, an inner rotor type motor. The first motor 51 includes, for example, a stator, a rotor that rotates relative to the stator when power is supplied, and an output shaft 52 that rotates together with the rotor. The output shaft 52 has a configuration equivalent to the output shaft 11a of the first motor 11 in the embodiment of the drive device 100 described above. The first motor 51 also has a first encoder 54 that detects the rotational speed of the output shaft 52.

[0056] The output shaft 52 is a cylindrical shaft member whose axis coincides with the rotation axis Ad parallel to the axle Aw. The output shaft 52 is provided rotatably about the rotation axis Ad with respect to a support part 70 described below. The output shaft 52 is inserted into a second through-hole 73 of the support part 70 and is supported rotatably about the rotation axis Ad with respect to the support part 70 via a bearing B5. A gear 53 is fixed to the output shaft 52.

[0057] The gear 53 is an external gear with teeth 53a formed on its outer circumferential surface. The gear 53 is fixed to the output shaft 52 so that its axis coincides with the rotation axis Ad. The teeth 53a mesh with teeth 38a formed on the gear 38 of the wheel main body 30. Torque from the first motor 51 is transmitted to the wheel main body 30 via the output shaft 52, gear 53, and gear 38.

[0058] The first motor 51 is supplied with power from a power source (not shown) provided on the body of the self-propelled vehicle on which the wheel 200 is mounted. When power is supplied, the first motor 51 rotates the wheel body 30 around the rotation axis Ad. The rotation direction and rotation speed of the output shaft 52 of the first motor 51 are controlled by a drive control device 80, which will be described later.

[0059] The arm driving unit 60 rotates the axle member 31 around the axle Aw relative to the support unit 70, which will be described later. The arm driving unit 60 includes a second motor 61. The second motor 61 is a rotational drive source for the axle member 31. Torque from the second motor 61 is transmitted to the arm 40 via the gear 34 of the axle member 31.

[0060] The second motor 61 has a configuration equivalent to the second motor 12 in the embodiment of the drive device 100 described above, and is, for example, an inner rotor motor. The second motor 61 includes, for example, a stator, a rotor that rotates relative to the stator when power is supplied, and an output shaft 62 that rotates together with the rotor. The output shaft 62 is coaxial with the axle Aw. The output shaft 62 is inserted into and fixed to the axle member 31. The output shaft 62 has a configuration equivalent to the output shaft 12a of the second motor 12 in the embodiment of the drive device 100 described above. The second motor 61 also has a second encoder 64 that detects the rotational speed of the output shaft 62.

[0061] The second motor 61 is supplied with power from a power source (not shown) provided on the body of the self-propelled vehicle on which the wheel 200 is mounted. When power is supplied, the second motor 61 rotates the axle member 31 around the axle Aw. The direction and speed of rotation of the output shaft 62 of the second motor 61 are controlled by a drive control device 80, which will be described later.

[0062] The support portion 70 supports the axle member 31, the arm drive unit 60, and the wheel drive unit 50. In the embodiment, the support portion 70 has a plate shape having a thickness in the direction of the axle Aw. In the embodiment, the support portion 70 supports the wheel main body 30 on the outer surface 70a side via the axle member 31. The outer surface 70a is the surface that faces the outside of the vehicle body when the wheel 200 is mounted on a self-propelled vehicle. The support portion 70 includes a first through hole 71, a first cylindrical portion 72, a second through hole 73, and a second cylindrical portion 74.

[0063] The first through-hole 71 is provided so that its axis coincides with the axle Aw. The axle member 31 is inserted into the first through-hole 71. The first through-hole 71 supports the axle member 31 via the bearing B1 so that the axle member 31 is rotatable around the axle Aw.

[0064] The first cylindrical portion 72 is provided so as to protrude toward the inner surface 70b of the support portion 70. The inner surface 70b is the surface opposite the outer surface 70a and is the side surface that faces toward the inside of the vehicle body when the wheel 200 is mounted on a motor vehicle. The inner circumferential surface of the first cylindrical portion 72 communicates with the first through-hole 71. The first cylindrical portion 72 supports the housing of the second motor 61.

[0065] The second through-hole 73 is provided so that its axis coincides with the rotation axis Ad. The output shaft 52 of the wheel drive unit 50 is inserted into the second through-hole 73. The second through-hole 73 supports the output shaft 52 via a bearing B5 so that the output shaft 52 is rotatable around the rotation axis Ad.

[0066] The second cylindrical portion 74 is provided to protrude toward the inner surface 70b of the support portion 70. The inner circumferential surface of the second cylindrical portion 74 communicates with the second through-hole 73. The second cylindrical portion 74 supports the housing of the first motor 51.

[0067] The support part 70 is fixed to a body 201 of a self-propelled vehicle (vehicle 300) on which the wheel 200 is mounted, for example, as shown in Fig. 7 described later. By fixing the support part 70 to the body 201, the axle Aw and rotation axis Ad of the wheel 200 are fixed to the body 201. Note that the support part 70 may be provided integrally with the body 201.

[0068] The drive control device 80 controls the rotation direction and rotation speed of the wheel body 30 and the arm 40. Specifically, in this embodiment, the drive control device 80 controls the rotation direction and rotation speed of the output shaft 52 of the first motor 51 and the output shaft 62 of the second motor 61. The drive control device 80 is provided, for example, on the body side of the self-propelled vehicle on which the wheel 200 is mounted. The drive control device 80 has a configuration equivalent to the drive control device 20 in the embodiment of the drive device 100 described above, and has the same functions as the drive control device 20. In other words, the drive control device 80 has a command value output unit 81 and a calculation unit 82 that have the same functions as the command value output unit 21 and the calculation unit 22 of the drive control device 20.

[0069] In the drive control device 80, the command value output unit 81 controls the first motor 51 and the second motor 61 by setting command values (first command value, second command value) and outputting them to the first motor 51 and the second motor 61 so that the rotational speed of the axle member 31 in the forward direction R1 is greater than the rotational speed of the wheel main body 30 in the forward direction R1. In this case, the axle member 31 rotates in the forward direction R1 relative to the wheel main body 30. In this way, when the drive control device 80 controls the rotational direction and rotational speed of the axle member 31 and the wheel main body 30 so that the axle member 31 rotates in the forward direction R1 relative to the wheel main body 30, the arm 40 rotates in the protruding direction Rp from the retracted position to the protruding position.

[0070] The command value output unit 81 controls the first motor 51 and the second motor 61 by setting command values (first command value, second command value) and outputting them to the first motor 51 and the second motor 61 so that the rotational speed of the axle member 31 in the forward direction R1 is smaller than the rotational speed of the wheel main body 30 in the forward direction R1. In this case, the axle member 31 rotates relative to the wheel main body 30 in the reverse direction R2. In this way, when the drive control device 80 controls the rotational direction and rotational speed of the axle member 31 and the wheel main body 30 so that the axle member 31 rotates relative to the wheel main body 30 in the reverse direction R2, the arm 40 rotates in the retracted direction Rs from the extended position to the retracted position.

[0071] The command value output unit 81 controls the first motor 51 and the second motor 61 by setting command values (first command value, second command value) so that the rotational speed of the axle member 31 in the forward direction R1 is equal to the rotational speed of the wheel main body 30 in the forward direction R1 and outputting the command values to the first motor 51 and the second motor 61. In this case, the axle member 31 does not rotate relative to the wheel main body 30. In this way, when the drive control device 80 controls the axle member 31 and the wheel main body 30 to rotate in the same rotational direction and at the same rotational speed so that the axle member 31 does not rotate relative to the wheel main body 30, the arm 40 maintains its position relative to the wheel main body 30.

[0072] In the drive control device 80, a calculation unit 82 calculates a first speed deviation in the first motor 51 and a second speed deviation in the second motor 61, calculates a reference value based on the calculation results, and uses the reference value to correct a second command value to be input to the second motor 61. When the second command value has been corrected, the corrected second command value is input to a driver (not shown) of the second motor 61.

[0073] Next, the configuration of a vehicle 300 as an application example of the wheel 200 will be described with reference to Fig. 6. Fig. 6 is a diagram that schematically shows an example configuration of a vehicle 300 equipped with the wheel 200. In Fig. 6, the traveling direction of the vehicle 300 when the wheel 200 rotates in a direction that allows it to travel over a step is the front of the vehicle 300. In other words, the front of the vehicle 300 is the right in Fig. 6. Fig. 6 is also a side view of the vehicle 300 as viewed from the right.

[0074] The vehicle 300 of the application form is a bogie including a vehicle body 201 and four wheels 200 (the wheel 200 disposed on the left side is not shown). The vehicle body 201 is equipped with, for example, a power source for supplying power to the first motor 51 and the second motor 61 (see FIG. 3), a drive control device 80 for controlling the rotation direction and rotation speed of the first motor 51 and the second motor 61, a detection device for detecting steps in the traveling direction, and the like. The detection device may include, for example, a sensor such as an infrared sensor for detecting the distance to the step. The detection device may include, for example, an imaging unit for capturing an image of the step, and may detect the step based on the captured image.

[0075] The four wheels 200 are fixed to the vehicle body 201 via support parts 70. The four wheels 200 are arranged on the left, right, front and rear of the vehicle body 201. As a result, the axles Aw and rotation axes Ad of the wheels 200 are fixed to the vehicle body 201. In the application form, the upper ends of the support parts 70 of the wheels 200 are fixed to the underside of the vehicle body 201. In the application form, the vehicle 300 has four wheels 200 arranged on the left, right, front and rear, but when the wheels 200 are applied to a self-propelled vehicle, three or more wheels 200 may be provided. Turning the vehicle 300 in the left and right directions does not use a steering device for steering, but uses the difference in rotational speed between the right wheel 200 and the left wheel 200.

[0076] Next, the operation of the vehicle 300 will be described. Figures 7 to 12 are diagrams showing an example of the operation of the vehicle 300. As shown in Figure 7, the vehicle 300 has not reached a step and is traveling on flat ground. In this case, the drive control device 80 controls the first motor 51 and the second motor 61 so that the axle member 31 and the wheel main body 30 rotate in the same rotational direction and at the same rotational speed, thereby maintaining the stored position of the arm 40 of the wheel 200.

[0077] When the arm 40 of the wheel 200 is in the stored position shown in Fig. 3, the claw portion 42 is stored radially inward from the outer periphery of the wheel body 30 and is not subjected to external force by coming into contact with the running surface of the wheel 200. When the arm 40 is in the stored position shown in Fig. 1, the claw portion 42 does not protrude radially outward from the outer periphery of the wheel body 30, so the wheel 200 maintains its circular shape and can run in the same way as a normal wheel.

[0078] The arm support shaft 36 of the wheel body 30 rotates around the axle Aw together with the wheel body 30. When the axle member 31, i.e., the gear 34, rotates in the same rotational direction and at the same rotational speed as the wheel body 30 (no relative rotation), the gear 34 does not rotate with respect to the teeth 41a of the arm 40, and therefore the arm 40, which is in the stored position, does not move from the stored position. In other words, when traveling on flat ground, the drive control device 80 controls the first motor 51 and the second motor 61 so that the axle member 31 and the wheel body 30 rotate in the same rotational direction and at the same rotational speed, thereby maintaining the stored position of the arm 40.

[0079] 8, when the vehicle 300 approaches a step, the drive control device 80 controls the first motor 51 and the second motor 61 of the wheel 200 so that the rotational speed of the axle member 31 in the forward direction R1 is greater than the rotational speed of the wheel main body 30 in the forward direction R1. This control causes the arm 40 to move from the retracted position to the extended position. The wheel 200 lifts the wheel main body 30 off the running surface, with the ground contact point Pc at the tip of the claw portion 42 serving as a fulcrum.

[0080] In this control, the drive control device 80 controls the rotation speed of the axle member 31, i.e., the gear 34, in the forward direction R1 to be greater than the rotation speed of the wheel main body 30 in the forward direction R1. In this case, the gear 34 rotates in the forward direction R1 relative to the tooth portion 41a of the arm 40. As a result, the arm 40 rotates in the protruding direction Rp about the arm rotation axis Aa. This rotation moves the arm 40, which is in the retracted position, to the protruding position. After the arm 40 moves to the protruding position, the drive control device 80 controls the gear 34 to rotate in the same direction and at the same rotation speed as the wheel main body 30 (no relative rotation). With this control, the wheel 200 rotates with the arm 40 maintained in the protruding position. The vehicle 300 continues traveling with the claw portion 42 protruding until the front wheel 200 reaches a step.

[0081] The timing for rotating the arm 40 in the protruding direction Rp may also be when the front wheel 200 reaches and hits a step. That is, when the approach of a step is detected by an imaging device or the like, the arm 40 may be rotated in the protruding direction Rp in advance before the front wheel 200 reaches the step, but when a collision with a step is detected by an acceleration sensor or the like, the arm 40 is rotated in the protruding direction Rp when the front wheel 200 reaches and hits the step.

[0082] As shown in FIG. 9, when the front wheel 200 of the vehicle 300 reaches a step, the tip of the claw 42 located on the front side of the front wheel 200 becomes caught on the upper surface of the step. By hooking the tip of the claw 42 on the step in this way, the vehicle can travel over the step. Note that depending on the rotational position of the claw 42 around the axle Aw, the claw 42 may not get caught on the step. In such a case, the wheel 200 spins in the forward direction R1 just before the step until one of the claws 42 gets caught on the upper surface of the step, and the adjacent claw 42 on the reverse direction R2 side gets caught on the step.

[0083] As shown in Figure 10, the wheel 200 continues to rotate in the forward direction R1. As a result, the front wheel 200 climbs up onto the step, using the claw portion 42 that is in contact with the upper surface of the step as a fulcrum. The wheel 200 continues to rotate in the forward direction R1. At this time, the front wheel 200 travels on the upper surface of the step, and the rear wheel 200 travels on the traveling surface below the step.

[0084] As shown in Fig. 11, the wheel 200 further rotates in the forward direction R1. As a result, the rear wheel 200 climbs up the step, using the claw portion 42 that contacts the upper surface of the step as a fulcrum. The wheel 200 further rotates in the forward direction R1. As a result, the front wheel 200 and the rear wheel 200 run on the upper surface of the step, as shown in Fig. 12.

[0085] After the front wheel 200 and the rear wheel 200 have traveled over the step, the drive control device 80 controls the first motor 51 and the second motor 61 so that the rotational speed of the axle member 31 in the forward direction R1 is smaller than the rotational speed of the wheel body 30 in the forward direction R1. Through this control, the wheel 200 moves the arm 40 from the extended position to the retracted position.

[0086] After the arm 40 reaches the stored position, the drive control device 80 controls the first motor 51 and the second motor 61 so that the axle member 31 and the wheel body 30 rotate in the same direction and at the same rotational speed. This control causes the wheel 200 to rotate while maintaining the stored position of the arm 40.

[0087] When traveling over a step, the drive control device 80 controls the first motor 51 and the second motor 61 so that the rotational speed of the axle member 31 in the forward direction R1 is greater than the rotational speed of the wheel body 30 in the forward direction R1. This control causes the wheel 200 to deform so that the arm 40 moves from the retracted position to the extended position. At this time, the drive control device 80 may control the rotational speed of the axle member 31 in the forward direction R1 to be greater than the rotational speed of the wheel body 30 in the forward direction R1, for example, by stopping or slowing down the rotation of the output shaft 52 of the first motor 51 in the forward direction R1 while maintaining the rotational speed of the output shaft 62 of the second motor 61 in the forward direction R1.

[0088] After the arm 40 reaches the protruding position shown in Figure 5, the drive control device 80 controls the first motor 51 and the second motor 61 so that the axle member 31 and the wheel body 30 rotate in the same direction and at the same rotational speed, thereby maintaining the protruding position of the arm 40.

[0089] When the rotation speed of the axle member 31, i.e., the gear 34, in the forward direction R1 is smaller than the rotation speed of the wheel body 30 in the forward direction R1, the gear 34 rotates in the reverse direction R2 relative to the tooth portion 41a of the arm 40, so that the arm 40 rotates in the storage direction Rs around the arm rotation axis Aa, and the arm 40, which is in the extended position, moves from the extended position to the stored position.

[0090] That is, when the vehicle finishes traveling over bumps and transitions to traveling on flat ground, the drive control device 80 controls the first motor 51 and the second motor 61 so that the rotational speed of the axle member 31 in the forward direction R1 is smaller than the rotational speed of the wheel body 30 in the forward direction R1, thereby moving the arm 40 from the extended position to the retracted position and deforming the wheel 200 into a circular shape. At this time, the drive control device 80 may, for example, stop or slow down the rotation of the output shaft 62 of the second motor 61 in the forward direction R1 while maintaining the rotational speed of the output shaft 52 of the first motor 51 in the forward direction R1, thereby controlling the rotational speed of the axle member 31 in the forward direction R1 to be smaller than the rotational speed of the wheel body 30 in the forward direction R1.

[0091] 3, the drive control device 80 controls the first motor 51 and the second motor 61 to maintain the stored position of the arm 40 so that the axle member 31 and the wheel body 30 rotate in the same direction and at the same rotational speed. As a result, the wheel 200 again maintains its circular shape and can travel in the same way as a normal wheel.

[0092] When the arm 40 is in the retracted position and the claw portion 42 is positioned radially inward from the outer periphery of the wheel body 30, the wheel 200 in contact with the running surface is subjected to an external force from the running surface. Also, when the arm 40 is in the protruding position and the claw portion 42 protrudes radially outward from the outer periphery of the wheel body 30, the arm 40 in contact with the running surface is subjected to an external force from the running surface. This external force may become a disturbance when controlling the rotational speed of the first motor 51 that rotates the wheel body 30 and the rotational speed of the second motor 61 that rotates the arm 40. In other words, when at least one of the wheel body 30 and the arm 40 is subjected to an external force, the speed difference between the rotational speed of the first motor 51 and the rotational speed of the second motor 61 may change due to the external force.

[0093] In response to this, the drive control device 80 calculates the first speed deviation in the first motor 51 and the second speed deviation in the second motor 61, calculates a reference value based on the calculation result, and uses the reference value to correct the second command value input to the second motor 61. When the second command value is corrected, the corrected second command value is input to a driver (not shown) of the second motor 61. Therefore, even when at least one of the wheel body 30 and the arm 40 is subjected to an external force, fluctuations in the speed difference between the rotational speed of the first motor 51 and the rotational speed of the second motor 61 can be suppressed.

[0094] As described above, the wheel 200 according to this embodiment includes the wheel body 30 that rotates around the axle by the first motor 51, the arm 40 that is supported on the wheel body 30 so as to be rotatable around the arm rotation axis Aa that is parallel to the wheel body 30 and that rotates between a stored position and an extended position by the second motor 61 as the wheel body 30 rotates, a command value output unit 81 that outputs a first command value to the first motor 51 and a second command value to the second motor 61, a calculation unit 82 that calculates a first speed deviation that is the difference between the first command value and a first rotational speed that is the rotational speed of the output shaft 52 of the first motor 51 when the first command value is input, and a second speed deviation that is the difference between the second command value and a second rotational speed that is the rotational speed of the output shaft 62 of the second motor 61 when the second command value is input, calculates a reference value based on the first speed deviation and the second speed deviation, and corrects the second command value input to the second motor 61 using the reference value, and a drive control device 80.

[0095] With this configuration, even when at least one of the wheel body 30 and the arm 40 is affected by external disturbances, etc., the speed difference in rotational speed between the first motor 51 and the second motor 61 can be maintained with high precision, thereby maintaining stability during rotation.

[0096] The vehicle 300 according to this embodiment includes the above-described wheel 200 and a vehicle body 201 that supports the wheel 200 rotatably around the axle Aw. With this configuration, the vehicle 300 is provided with the wheel 200 that can maintain stability during rotation, and therefore can run stably.

[0097] [Other examples of wheels and vehicles] Next, another example of the wheel and vehicle will be described. Fig. 13 is a diagram schematically showing a vehicle 400 according to another example. As shown in Fig. 13, the vehicle 400 has a body 401, a handle 402, driving wheels (wheels) 403, and driven wheels 404.

[0098] The vehicle body 401 is, for example, a loading platform on which luggage or the like can be loaded. The vehicle body 401 is, for example, a steel frame. On the front side in the traveling direction of the vehicle 400, one driven wheel 404 is attached to each side of the vehicle body 401. On the rear side in the traveling direction, one drive wheel 403 is attached to each side of the vehicle body 401. Also, a handle portion 402 is provided facing upward at the rear end of the vehicle body 401.

[0099] 14 is a diagram schematically illustrating an example of a drive wheel 403. As shown in FIG. 14, the drive wheel 403 has a drive unit 405 including a drive source 410 and a drive control unit 420, a coupling mechanism 430, and a wheel body 440.

[0100] The driving source 410 includes a first motor 411 and a second motor 412. The first motor 411 and the second motor 412 correspond to the first motor 11 and the second motor 12 in the embodiment of the driving device 100 described above, respectively, and are, for example, inner rotor motors. The first motor 411 and the second motor 412 each include, for example, a stator, a rotor that rotates relative to the stator when power is supplied, and output shafts 411a and 412a that rotate together with the rotors. The first motor 411 includes a first encoder 413 that detects the rotation speed of the output shaft 411a. The second motor 412 includes a second encoder 414 that detects the rotation speed of the output shaft 412a.

[0101] The drive control device 420 controls the rotational movement and turning movement of the wheel body 440 of the drive wheel 403. Specifically, in this embodiment, the drive control device 420 controls the rotation direction and rotation speed of the output shaft 411a of the first motor 411 and the output shaft 412a of the second motor 412. The drive control device 420 has a configuration corresponding to the drive control device 20 in the embodiment of the drive device 100 described above, and has the same functions as the drive control device 20. In other words, the drive control device 420 has a command value output unit 421 and a calculation unit 422 that have the same functions as the command value output unit 21 and the calculation unit 22 of the drive control device 20.

[0102] The coupling mechanism 430 couples the driving source 410 and the wheel body 440. The coupling mechanism 430 transmits the driving force of the driving source 410 to the wheel body 440 so that the wheel body 440 rotates around the axle Ax and turns around the turning axis As by the driving force of the driving source 410, depending on the speed difference between the rotational speed of the first motor 411 and the rotational speed of the second motor 412.

[0103] The connecting mechanism 430 has a first gear mechanism 431 , a belt mechanism 432 , a cylindrical shaft 433 , a second gear mechanism 434 , an output gear mechanism 435 , a helical gear mechanism 436 , a belt mechanism 437 , a steering arm 438 , and a crank 439 .

[0104] The first gear mechanism 431 has an external gear 431a and a bevel gear 431b. The external gear 431a is fixed to an output shaft 411a of the first motor 411. The bevel gear 431b meshes with the external gear 431a and an output gear 435a, which will be described later.

[0105] The belt mechanism 432 has pulleys 432a and 432b and a belt 432c. The pulley 432a is fixed to an output shaft 412a of the second motor 412. The pulley 432b is fixed to a cylindrical shaft 433, which will be described later. The belt 432c is stretched between the pulleys 432a and 432b, and transmits the rotation of the pulley 432a to the pulley 432b.

[0106] The cylindrical shaft 433 is disposed so as to surround the output shaft 411a of the first motor 411. The cylindrical shaft 433 shares a common axis with the output shaft 411a via, for example, a bearing (not shown) and is disposed so as to be rotatable independently of the output shaft 411a.

[0107] The second gear mechanism 434 has an external gear 434a and a bevel gear 434b. The external gear 434a is fixed to the cylindrical shaft 433. The bevel gear 434b meshes with the external gear 434a and an output gear 435a, which will be described later.

[0108] The output gear mechanism 435 has an output gear 435a and a shaft member 435b. The output gear 435a is an external gear and meshes with the bevel gears 431b and 434b. The output gear 435a is fixed to one end of the shaft member 435b, and a helical gear 436a (described later) is fixed to the other end. The shaft member 435b is rotatably supported by a crank 439.

[0109] The helical gear mechanism 436 has helical gears 436a and 436b and a shaft member 436c. The helical gear 436a rotates integrally with a shaft member 435b of the output gear mechanism 435. The helical gear 436b is fixed to the shaft member 436c and meshes with the helical gear 436a. The shaft member 436c is disposed so that its axis intersects with the shaft member 435b of the output gear mechanism 435, and rotates integrally with the helical gear 436b.

[0110] The belt mechanism 437 has pulleys 437a and 437b and a belt 437c. The pulley 437a is fixed to a shaft member 436c of the helical gear mechanism 436 and rotates integrally with the shaft member 436c. The pulley 437b is fixed to the wheel body 440 and rotates integrally with the wheel body 440 in the direction around the wheel axis Aw. The belt 437c transmits the rotation of the pulley 437a to the pulley 437b.

[0111] The steering arm 438 is connected to a motor support mechanism 450. The motor support mechanism 450 supports the first motor 411 and the second motor 412. The steering arm 438 rotatably supports the output shaft 411a of the first motor 411 via a bearing (not shown). The steering arm 438 rotatably supports the cylindrical shaft 433 via a bearing (not shown). When the output gear 435a rotates around the turning axis As, the steering arm 438, which supports the shaft member 435b to which the output gear 435a is fixed, rotates. When the steering arm 438 rotates, the crank 439 supported by the steering arm 438 and the wheel main body 440 supported by the crank 439 rotate.

[0112] The crank 439 is held by the steering arm 438 and supports the shaft member 436c of the helical gear mechanism 436. The steering arm 438 supports the output gear mechanism 435, the helical gear mechanism 436, the belt mechanism 437, and the wheel main body 440 via the crank 439.

[0113] The configuration of the coupling mechanism 430 is not limited to the above configuration and may be different. For example, the coupling mechanism 430 may have different types and arrangements of gears from those of the above configuration.

[0114] The wheel body 440 has an axle member 441 and a wheel body 442. The axle member 441 is fixed to the pulley 437b. The wheel body 442 is fixed to the axle member 441. The wheel body 442 rotates integrally with the pulley 437b and the axle member 441 in the direction around the wheel axis Ax. The wheel body 440 is supported by the steering arm 438 via a crank 439. Therefore, the wheel body 440 rotates around the rotation axis As.

[0115] When the external gear 431a and the external gear 434a rotate in the same direction and at the same rotational speed, there is no difference in rotational speed between them. Therefore, the output gear 435a, which meshes with them via the bevel gears 431b and 434b, does not rotate. In this case, the force from the external gear 431a to rotate the output gear 435a around the rotation axis As and the force to rotate the external gear 434a around the rotation axis As act in the same direction. Therefore, the output gear 435a rotates around the rotation axis As without rotating. When the output gear 435a rotates around the rotation axis As, the steering arm 438 rotates around the rotation axis As together with the output gear 435a. As a result, the wheel main body 440 rotates around the rotation axis As, changing the traveling direction.

[0116] When the external gear 431a and the external gear 434a rotate in opposite directions at the same rotational speed, the absolute values of their rotational speeds are the same, but their rotational directions are opposite. In this case, a difference in rotational speed occurs between them. As a result, the output gear 435a rotates via the bevel gears 431b and 434b, respectively. Also, in this case, because the absolute values of their rotational speeds are the same, the force from the external gear 431a to rotate the output gear 435a around the rotation axis As and the force from the external gear 434a to rotate the output gear 435a around the rotation axis As cancel each other out and become zero. In this case, the output gear 435a does not rotate around the rotation axis As. As a result, the output gear 435a rotates around the rotation axis Ab without rotating. When the output gear 435a rotates around the rotation axis Ab, the rotation is transmitted to the wheel body 440 via the belt mechanism 437, and the wheel body 440 rotates in the direction around the axle Aw.

[0117] When the external gear 431a rotates in one direction at a predetermined rotational speed and the external gear 434a does not rotate, a difference in rotational speed occurs between the two. Furthermore, a force acts on the output gear 435a to rotate it around the rotation axis As. As a result, the output gear 435a rotates around the rotation axis Ab and also revolves around the rotation axis As. In this case, the wheel main body 440 revolves around the rotation axis As while rotating around the axle Aw.

[0118] As described above, the drive wheel 403 according to this embodiment can rotate around the axle Aw by the first motor 411 and the second motor 412, and includes a wheel body 440 provided so as to be able to turn around the turning axis As perpendicular to the axle Aw in accordance with the speed difference between the rotation speed of the first motor 411 and the rotation speed of the second motor 412, a command value output unit 421 that outputs a first command value to the first motor 411 and a second command value to the second motor 412, and a control unit 422 that receives the first command value and the second command value. and a calculation unit 422 that calculates a first speed deviation, which is the difference between a first command value and a first rotation speed, which is the rotation speed of an output shaft 411a of the first motor 411 when the first command value is input, and a second speed deviation, which is the difference between a second command value and a second rotation speed, which is the rotation speed of an output shaft 412a of the second motor 412 when the second command value is input, calculates a reference value based on the first speed deviation and the second speed deviation, and corrects the second command value to be input to the second motor 412 using the reference value.

[0119] With this configuration, even when the wheel body 440 is affected by external disturbances, etc., the speed difference in rotational speed between the first motor 411 and the second motor 412 can be maintained with high precision, thereby maintaining stability during rotation and cornering.

[0120] The technical scope of the present invention is not limited to the above-described embodiment, and appropriate modifications can be made without departing from the spirit of the present invention. For example, in the above-described embodiment, the drive control device 20 corrects the rotation speed of the second motor 12, which has a smaller torque, when the torque of the first motor 11 is greater than the torque of the second motor 12. However, the present invention is not limited to this. The drive control device 20 may also correct the rotation speed of the motor with a larger torque or a motor with approximately the same torque. [Explanation of symbols]

[0121] 10,410 Drive source 11,51,411 First motor 11a, 12a, 15a, 16a, 52, 62, 411a, 412a output shaft 11b,12b drivers 12,61,412 Second motor 13,54,413 1st Encoder 14,64,414 Second Encoder 15 1st reducer 16 2nd reducer 20,80,420 Drive control device 21,81,421 Command value output section 22,82,422 Arithmetic unit 30,440,442 Wheel body 31,441 Axle members 34, 38, 53 Gears 36 Arm support axis 40 Arm 41 Base 42 Claw 50 Wheel drive unit 60 Arm drive unit 100,405 Drive unit 200 wheels 201,401 Body 300,400 vehicles 403 Drive Wheel 430 Connection mechanism 431 First Gear Mechanism 432,437 Belt mechanism 433 Cylindrical shaft 434 Second Gear Mechanism 435 Output gear mechanism 436 Helical Gear Mechanism 438 Steering Arm 439 Crank

Claims

1. a command value output unit that outputs a first command value to a first motor that rotates a first rotational object and outputs a second command value to a second motor that rotates a second rotational object different from the first rotational object; a calculation unit that calculates a first speed error, which is a difference between the first command value and a first rotation speed, which is a rotation speed of an output shaft of the first motor when the first command value is input, and a second speed error, which is a difference between the second command value and a second rotation speed, which is a rotation speed of an output shaft of the second motor when the second command value is input, calculates a reference value based on the first speed error and the second speed error, and corrects the second command value input to the second motor using the reference value; A drive control device comprising:

2. an output shaft of the first motor is connected to the first rotational object via a first reducer having a reduction ratio of a first value; an output shaft of the second motor is connected to the second rotational object via a second reducer having a second reduction ratio; The calculation unit calculates a difference between a value obtained by multiplying the first speed deviation by the first value and a value obtained by multiplying the second speed deviation by the second value, and calculates a value obtained by dividing the calculated difference by the second value as the reference value. The drive control device according to claim 1 .

3. The calculation unit corrects the second command value by subtracting the reference value from the output second command value. The drive control device according to claim 2 .

4. a first motor that rotates a first rotation object; a second motor that rotates a second rotational object different from the first rotational object; a drive control device including: a command value output unit that outputs a first command value for the first motor and a second command value for the second motor; and a calculation unit that calculates a first speed error that is a difference between the first command value and a first rotation speed that is a rotation speed of an output shaft of the first motor when the first command value is input, and a second speed error that is a difference between the second command value and a second rotation speed that is a rotation speed of an output shaft of the second motor when the second command value is input, calculates a reference value based on the first speed error and the second speed error, and corrects the second command value input to the second motor using the reference value; A drive unit comprising:

5. The torque for the second motor to rotate the second rotational object is smaller than the torque for the first motor to rotate the first rotational object. The drive device according to claim 4.

6. a wheel body that rotates around an axle by a first motor; an arm supported by the wheel body so as to be rotatable about an arm rotation axis parallel to the wheel body, and which rotates between a stored position and a protruding position by a second motor in accordance with the rotation of the wheel body; a drive control device including: a command value output unit that outputs a first command value for the first motor and a second command value for the second motor; and a calculation unit that calculates a first speed error that is a difference between the first command value and a first rotation speed that is a rotation speed of an output shaft of the first motor when the first command value is input, and a second speed error that is a difference between the second command value and a second rotation speed that is a rotation speed of an output shaft of the second motor when the second command value is input, calculates a reference value based on the first speed error and the second speed error, and corrects the second command value input to the second motor using the reference value; A wheel equipped with:

7. a wheel body that is rotatable about an axle by a first motor and a second motor and that is rotatable about a pivot axis perpendicular to the axle in accordance with a speed difference between a rotation speed of the first motor and a rotation speed of the second motor; a drive control device including: a command value output unit that outputs a first command value for the first motor and a second command value for the second motor; and a calculation unit that calculates a first speed error that is a difference between the first command value and a first rotation speed that is a rotation speed of an output shaft of the first motor when the first command value is input, and a second speed error that is a difference between the second command value and a second rotation speed that is a rotation speed of an output shaft of the second motor when the second command value is input, calculates a reference value based on the first speed error and the second speed error, and corrects the second command value input to the second motor using the reference value; A wheel equipped with:

8. A wheel according to claim 6 or claim 7; a vehicle body that supports the wheels rotatably around the axles; A vehicle equipped with:

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