trolley

Abstract

This invention provides a trolley capable of performing appropriate rotational movements. The trolley (1) includes: a body (2); left and right omnidirectional wheels (3); left and right drive units (4); handles (5) provided on the body; sensors (6) for detecting the front-rear load, left-right load, and torque about the vertical axis applied to the handles; and a control device (7) for controlling the drive units based on the front-rear load, left-right load, and torque about the vertical axis detected by the sensors. The control device sets a target front-rear speed of the body based on the front-rear load, sets a target left-right speed of the body based on the left-right load, sets a target angular velocity of the body about the vertical axis based on the torque about the vertical axis, and corrects the target left-right speed based on the target angular velocity so that the absolute value of the target angular velocity increases while the absolute value of the target left-right speed decreases, and controls the drive units based on the target front-rear speed, the corrected target left-right speed, and the target angular velocity.

Description

Technical Field

[0001] This invention relates to a trolley. Background Technology

[0002] Patent document 1 discloses a power-assisted trolley having: a handle for detecting the user's operating force; and a power-assisted control unit for driving and steering a drive wheel based on the operating force input to the handle.

[0003] Patent document 2 discloses an omnidirectional wheel that allows the vehicle body to move in all directions along the floor surface.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 2004-114800

[0007] Patent Document 2: Japanese Patent Application Publication No. 2017-210035 Summary of the Invention

[0008] The problem that the invention aims to solve

[0009] If the omnidirectional wheels of Patent Document 2 are applied to the wheels of the trolley in Patent Document 1, the trolley can move parallel to the left and right. Consider this: the trolley's control device sets a target left and right speed based on the load applied to the handle in the left and right direction, and drives the omnidirectional wheels in the left and right directions based on the target left and right speed. Furthermore, consider this: a target angular velocity about the vertical axis is set based on the torque applied to the handle about the vertical axis, and a difference is given to the forward and backward speeds of the left and right omnidirectional wheels based on the target angular velocity. However, when the user wants to turn the trolley and operates the handle, it is difficult to apply only the torque about the vertical axis to the handle without applying a load in the left and right direction. Therefore, when the user performs a turning operation, it is possible to apply an unintended left and right load to the handle, causing the trolley to move in an unintended left or right direction.

[0010] The objective of this invention is to provide a trolley capable of performing appropriate rotational movements, in view of the above background.

[0011] Technical means to solve the problem

[0012] To address the aforementioned problem, one embodiment of the present invention provides a trolley (1) comprising: a body (2); left and right omnidirectional wheels (3) disposed on the body, enabling the body to move in all directions along the floor surface; left and right drive units (4) driving each of the omnidirectional wheels; handles (5) disposed on the body for user operation; sensors (6) detecting front-rear loads, left-right loads, and torques about a vertical axis applied to the handles; and a control device (7) controlling the drive units based on the front-rear loads, left-right loads, and torques about a vertical axis detected by the sensors. The control device sets a target front-rear speed of the body based on the front-rear loads, sets a target left-right speed of the body based on the left-right loads, sets a target angular velocity of the body about a vertical axis based on the torques about a vertical axis, and corrects the target left-right speed based on the target angular velocity such that the absolute value of the target angular velocity increases as the absolute value of the target left-right speed decreases. The drive units are controlled based on the target front-rear speed, the corrected target left-right speed, and the target angular velocity.

[0013] According to this embodiment, a trolley capable of performing appropriate rotational movements can be provided. Because corrections are made to reduce the target lateral velocity in response to an increase in the target angular velocity, the trolley's left-right movement can be suppressed even if the user applies an unintentional lateral load to the handle during rotation.

[0014] In the described embodiment, the control device may set upper limits for left and right speeds based on the target angular velocity. The upper limits for left and right speeds are set such that the absolute value of the target angular velocity increases, and the absolute value of the upper limits for left and right speeds becomes smaller. The target left and right speeds are also corrected so that the absolute values ​​of the target left and right speeds are below the upper limits for left and right speeds.

[0015] According to this embodiment, the upper limit of the left and right speed is reduced in response to the increase of the target angular velocity, thereby suppressing the movement in the left and right directions during rotation.

[0016] In the embodiments described above, the upper limit of the left and right speeds may also be set to a value above a predetermined lower limit.

[0017] According to this embodiment, the trolley moves slightly to the left or right in response to the user's rotation operation. This allows the user's operating feel to closely approximate the trolley's response.

[0018] In the aforementioned embodiments, the upper limit of the left and right velocities may also have a negative linear relationship with the target angular velocity in the region above the lower limit.

[0019] According to this embodiment, the upper limit of the left and right velocities can be reduced in response to the increase of the target angular velocity.

[0020] In the described embodiments, the control device may also correct the target angular velocity so that the absolute value of the target angular velocity is below a predetermined upper limit value of angular velocity, and control the drive unit based on the corrected target angular velocity instead of the target angular velocity.

[0021] According to this embodiment, by setting an upper limit for the angular velocity of the trolley around the vertical axis, the operation of the trolley becomes easier.

[0022] In the aforementioned embodiments, the control device may also correct the left and right velocities of the target based on the correction value of the target angular velocity, such that the absolute value of the correction value of the target angular velocity increases, and the absolute value of the left and right velocities of the target becomes smaller.

[0023] According to this embodiment, the left and right velocities of the target are corrected based on the corrected target angular velocity, thus preventing excessive decrease in the left and right velocities of the target. As a result, the trolley can generate a driving force that is more in line with the user's operating feel.

[0024] In the described embodiment, the control device may also correct the target forward and backward speed so that the absolute value of the target forward and backward speed is below a predetermined upper limit value, and control the drive unit based on the corrected target forward and backward speed instead of the target forward and backward speed.

[0025] According to this embodiment, by setting an upper limit for the forward and backward speed of the trolley, the operation of the trolley becomes easier.

[0026] The effects of the invention

[0027] Based on the above structure, a trolley capable of performing appropriate rotational movements can be provided. Attached Figure Description

[0028] Figure 1 This is a perspective view of the trolley used in the implementation method.

[0029] Figure 2 This is a floor plan of the trolley.

[0030] Figure 3 This is a cross-sectional view of an omnidirectional wheel.

[0031] Figure 4 This is a side view of the main wheel.

[0032] Figure 5 This is a block diagram representing the control device of the trolley.

[0033] Figure 6 It is a flowchart representing the control process executed by the control device.

[0034] Figure 7 It is a mapping diagram showing the relationship between the target's angular velocity and the upper limit of its left and right velocities.

[0035] Figure 8 This is an explanatory diagram showing the trajectory of the trolley during rotation.

[0036] Explanation of symbols

[0037] 1: Cart

[0038] 2: Body

[0039] 3: Omnidirectional wheels

[0040] 4: Drive Unit

[0041] 5: Handle

[0042] 6: Force sensor

[0043] 7: Control device

[0044] 17: Framework

[0045] 18: Drive disk

[0046] 18A: Base

[0047] 18B: Drive roller

[0048] 19: Main wheel

[0049] 25: Electric motor

[0050] 27: Belt

[0051] 31: Core

[0052] 32: Driven roller Detailed Implementation

[0053] Hereinafter, embodiments of the trolley of the present invention will be described with reference to the accompanying drawings. The trolley will be used as a reference for defining each aspect.

[0054] like Figure 1 As shown, the trolley 1 has: a body 2; at least one omnidirectional wheel 3 disposed on the body 2, allowing the body 2 to move in all directions along the floor surface; a drive unit 4, driving each omnidirectional wheel 3; a handle 5 disposed on the body 2, receiving operation from the user; a force sensor 6, detecting the load applied to the handle 5; and a control device 7, controlling the drive unit 4 based on the load detected by each of the force sensors 6.

[0055] The vehicle body 2 extends front to back. The rear part 2A of the vehicle body 2 extends higher than the front part 2B. A support platform 11 for supporting other devices is provided at the front part 2B of the vehicle body 2. Devices supported by the support platform 11 include, for example, inspection machines containing X-ray scanners. These devices can be secured to the support platform 11. Inside the rear part 2A of the vehicle body 2, control devices 7, batteries, and various sensors can be provided.

[0056] In this embodiment, a pair of omnidirectional wheels 3 are provided at the lower part of the rear portion 2A of the vehicle body 2. Furthermore, left and right casters 13 are supported by a suspension at the lower part of the front portion 2B of the vehicle body 2. The suspension has an arm 14 positioned below the vehicle body 2 and extending laterally, and a spring 15 and a shock absorber 16 positioned between the vehicle body 2 and the arm 14. Each caster 13 is positioned below the left and right ends of the arm 14. Each caster 13 has: a fork 13A, rotatably coupled to the arm 14 with its vertically extending axis as the center; and a wheel 13B, rotatably supported on the fork 13A with its horizontally extending axis as the center. The fork 13A rotates freely relative to the arm 14, and the wheel 13B rotates freely relative to the fork 13A.

[0057] like Figure 2 As shown, a pair of omnidirectional wheels 3 are arranged spaced apart on the left and right sides. In this embodiment, the pair of omnidirectional wheels 3 are arranged on the lower left and lower right sides of the rear part 2A of the vehicle body 2. Figure 3 As shown, each omnidirectional wheel 3 has a frame 17, a pair of drive discs 18 rotatably supported on the frame 17, and an annular main wheel 19 disposed between the pair of drive discs 18.

[0058] like Figure 1 as well as Figure 3 As shown, the frame 17 has: an upper frame portion 17A attached to the lower part of the vehicle body 2, and a pair of frame side portions 17B extending downward from the left and right ends of the upper frame portion 17A. A left-right extending support shaft 21 is mounted at the lower end of the pair of frame side portions 17B. A pair of drive discs 18 are rotatably supported on the support shaft 21. The pair of drive discs 18 rotate about the axis Y1 of the support shaft 21. The position of each drive disc 18 relative to the support shaft 21 in the left-right direction is restricted. The drive discs 18 are spaced apart from each other in the left-right direction and face each other.

[0059] Drive discs 18 are respectively disposed on both sides of the annular main wheel 19, applying frictional force to the main wheel 19 to cause the main wheel 19 to rotate around the central axis and around the annular axis. The drive discs 18 have: a disc-shaped base 18A, rotatably supported on the frame 17; and a plurality of drive rollers 18B, inclined relative to each other and rotatably supported on the outer periphery of the base 18A, and in contact with the main wheel 19. The base 18A is coaxially arranged with the support shaft 21.

[0060] On opposite surfaces of each drive disc 18, driven pulleys 18C are provided. Driven pulleys 18C are coaxially arranged with the drive discs 18. A drive unit 4 is located at the lower part of the vehicle body 2 and has multiple electric motors 25 corresponding to each drive disc 18. In this embodiment, four electric motors 25 are provided corresponding to the four drive discs 18. A drive pulley 26 is provided on the output shaft of each electric motor 25. The corresponding drive pulley 26 is connected to the driven pulley 18C via a belt 27. Each electric motor 25 rotates independently, thereby causing each drive disc 18 to rotate independently.

[0061] like Figure 4 As shown, the main wheel 19 is annular and coaxially arranged between a pair of drive discs 18, and contacts a plurality of drive rollers 18B, thereby being rotatable about a central axis and about the axis of the annular shape. The main wheel 19 has an annular core 31 and a plurality of driven rollers 32 rotatably supported on the core 31. The plurality of driven rollers 32 are arranged at equal intervals along the circumference of the core 31. Each driven roller 32 is rotatably supported on the core 31 about the axis A1 (the axis of the annular shape) of the annular core 31. Each driven roller 32 can rotate about the tangent of the core 31 at various positions relative to the core 31. Each driven roller 32 rotates relative to the core 31 under the influence of an external force.

[0062] The main wheel 19 is arranged along the outer periphery of a pair of drive discs 18 and contacts a plurality of drive rollers 18B provided on each drive disc 18. The drive rollers 18B of each drive disc 18 contact the inner periphery of the main wheel 19, clamping the main wheel 19 from both sides. Furthermore, the drive rollers 18B of the left and right drive discs 18 contact the inner periphery of the main wheel 19, thereby limiting the radial displacement of the drive discs 18 towards the axis Y1. Thus, the main wheel 19 is supported by the left and right drive discs 18, and the central axis of the main wheel 19 (core 31) is coaxial with the axis Y1 of the left and right drive discs 18. The main wheel 19 contacts the plurality of drive rollers 18B of the left and right drive discs 18 in a plurality of driven rollers 32.

[0063] In each omnidirectional wheel 3, when a pair of drive discs 18 rotate in the same direction at the same speed, the main wheel 19 rotates together with the pair of drive discs 18. That is, the main wheel 19 rotates forward or backward around its own axis of rotation, which is aligned with axis Y1. At this time, the drive rollers 18B of the drive discs 18 and the driven rollers 32 of the main wheel 19 do not rotate relative to the core 31. In each omnidirectional wheel 3, when a speed difference is generated between the pair of drive discs 18, a component force orthogonal to the circumferential (tangential) force caused by the rotation of the pair of drive discs 18 acts from the left and right drive rollers 18B to the driven rollers 32 of the main wheel 19. Since the axis of the drive rollers 18B is inclined relative to the circumference of the drive rollers 18B, a component force is generated between the drive discs 18 due to the speed difference. With the aid of this component force, the drive rollers 18B rotate relative to the base 18A, and the driven rollers 32 rotate relative to the core 31. As a result, the main wheel 19 generates a driving force in the left and right directions.

[0064] The trolley 1 moves forward by rotating the left and right omnidirectional wheels 3 at the same speed in the forward direction. The trolley 1 moves backward by rotating the left and right omnidirectional wheels 3 at the same speed in the backward direction. The speed difference created by the rotation of the left and right omnidirectional wheels 3 in the forward and backward directions causes the trolley 1 to turn to the right or left. The rotation of the driven rollers 32 of each main wheel 19 of the left and right omnidirectional wheels 3 causes the trolley 1 to move parallel to the right or left.

[0065] like Figure 1 as well as Figure 2 As shown, a handlebar bracket 35 protruding upwards is provided at the upper part of the rear portion 2A of the vehicle body 2. The handlebar 5 is supported on the handlebar bracket 35 via a force sensor 6. The force sensor 6 can be a triaxial force sensor that detects loads along two axes orthogonal to each other on a horizontal plane and torques centered on the vertical axis (z-axis). In this embodiment, the force sensor 6 detects the loads applied to the handlebar 5 in the forward / backward direction (x-axis), i.e., the forward / backward load, the loads in the left / right direction (y-axis), i.e., the left / right load, and the torques about the vertical axis (z-axis). The force sensor 6 has a body portion and an input portion provided in the body portion. The body portion is attached to the handlebar bracket 35.

[0066] The handle 5 has a horizontal portion 5A extending to the left and right and a pair of vertical portions 5B extending forward from the left and right ends of the horizontal portion 5A. The central portion of the horizontal portion 5A in the left and right direction is connected to the input portion of the force sensor 6.

[0067] like Figure 2 As shown, when the user applies an external force fh and a torque mhz to the position rh of handle 5, the force sensor 6 detects the force fs and the torque msz at the sensor position rs. The detected force fs includes the front-rear load fs1 as the front-rear component and the left-right load fs2 as the left-right component.

[0068] The control device 7 is an electronic control unit (ECU) that includes a processor such as a central processing unit (CPU), non-volatile memory (read-only memory, ROM), and volatile memory (random access memory, RAM). The control device 7 controls the drive unit 4 by executing arithmetic operations in the processor based on a program stored in the non-volatile memory. The control device 7 can be configured as a single piece of hardware or as a unit containing multiple pieces of hardware. Furthermore, at least a portion of each functional unit of the control device 7 can be implemented in hardware such as large-scale integrated circuits (LSI), application-specific integrated circuits (ASIC), or field-programmable gate arrays (FPGA), or through a combination of software and hardware.

[0069] like Figure 5 As shown, the control device 7 is connected to the force sensor 6 and the drive unit 4. The force sensor 6 outputs a detection signal to the control device 7. The control device 7 outputs a control signal to the drive unit 4.

[0070] The control device 7 controls the drive unit 4 based on signals from the force sensor 6. The force sensor 6 is installed between the vehicle body 2 and the handle 5. The force sensor 6 detects the magnitude and direction of the operating force (load) applied by the user to the handle 5. The control device 7 can determine the target forward / backward speed vt1, the target left / right speed vt2, and the target angular velocity ωt of the trolley 1 based on the signals from the force sensor 6, and determine the control amount of each electric motor 25 of the drive unit 4 based on the target forward / backward speed vt1, the target left / right speed vt2, and the target angular velocity ωt.

[0071] Control device 7 is based on Figure 6 The flowchart shown illustrates the control of the drive unit 4. First, the control device 7 acquires the detected force fs and detected torque msz(S1) from the force sensor 6 based on the signal from the force sensor 6. The detected force fs includes the front and rear loads fs1 and the left and right loads fs2.

[0072] Next, the control device 7 sets the target front-rear velocity vt1 of the vehicle body 2 based on the front and rear load fs1, sets the target left and right velocity vt2 of the vehicle body 2 based on the left and right load fs2, and sets the target angular velocity ωt(S2) of the vehicle body 2 about the vertical axis based on the torque msz about the vertical axis.

[0073] The target forward / backward velocity vt can be set, for example, by multiplying the forward / backward load fs1 by a predetermined coefficient k1. Similarly, the target left / right velocity vt2 can be set, for example, by multiplying the left / right load fs2 by a predetermined coefficient k2. Furthermore, the target angular velocity ωt can be set, for example, by multiplying the torque msz about the vertical axis by a predetermined coefficient k3. The target angular velocity ωt is set with a reference point as the center. The reference point can be set to a position that coincides with the center of gravity of the trolley 1 when viewed from above. In this embodiment, the reference point is located at the midpoint of the line segment connecting a pair of omnidirectional wheels 3. However, the methods for setting the target forward / backward velocity vt1, the target left / right velocity vt2, and the target angular velocity ωt are not limited to these.

[0074] Next, the control device 7 corrects the target angular velocity ωt so that the absolute value of the target angular velocity ωt is below a predetermined upper limit value for angular velocity (S3). The upper limit value for angular velocity can be a preset predetermined value. For example, if the absolute value of the target angular velocity ωt is greater than the upper limit value for angular velocity, the control device 7 can set the value of the target angular velocity ωt in such a way that the absolute value of the target angular velocity ωt becomes equal to the upper limit value for angular velocity. Moreover, if the absolute value of the target angular velocity ωt is less than the upper limit value for angular velocity, the control device 7 can directly set the target angular velocity ωt to the corrected target angular velocity ωt.

[0075] Next, control device 7 sets the upper limit values ​​of the left and right velocities vt2u (S4) based on the corrected target angular velocity ωt. Control device 7 can, for example, use... Figure 7 The mapping diagram shown sets the upper limits of left and right velocities, vt2u, based on the target angular velocity ωt. The upper limits vt2u are set such that the absolute value of vt2u decreases as the absolute value of the target angular velocity ωt increases. The upper limits vt2u are set to values ​​above a predetermined lower limit vt2ul. The lower limit vt2ul is set to a value greater than 0. The upper limits vt2u can have a negative linear relationship with the target angular velocity ωt in the region above the lower limit vt2ul.

[0076] Next, the control device 7 corrects the target left-right speed vt2 based on the target left-right speed vt2 and the upper limit value of the left-right speed vt2u, so that the absolute value of the target left-right speed vt2 becomes less than or equal to the upper limit value of the left-right speed vt2u (S5). For example, if the absolute value of the target left-right speed vt2 is greater than the upper limit value of the left-right speed vt2u, the control device 7 can correct the value of the target left-right speed vt2 so that the absolute value of the target left-right speed vt2 is equal to the upper limit value of the left-right speed vt2u. Moreover, if the absolute value of the target left-right speed vt2 is less than the upper limit value of the left-right speed vt2u, the control device 7 can directly set the target left-right speed vt2 to the corrected target left-right speed vt2.

[0077] Next, the control device 7 corrects the target forward / backward speed vt1 so that the absolute value of the target forward / backward speed vt1 is below a predetermined upper limit value for forward / backward speed (S6). The upper limit value for forward / backward speed can be a predetermined value set in advance. For example, if the absolute value of the target forward / backward speed vt1 is greater than the upper limit value for forward / backward speed, the control device 7 can set the value of the target forward / backward speed vt1 in such a way that the absolute value of the target forward / backward speed vt1 becomes equal to the upper limit value for forward / backward speed. Moreover, if the absolute value of the target forward / backward speed vt1 is less than the upper limit value for forward / backward speed, the control device 7 can directly set the target forward / backward speed vt1 to the corrected target forward / backward speed vt1.

[0078] The control device 7 controls the drive unit 4 (S7) based on the corrected target forward / backward velocity vt1, the corrected target left / right velocity vt2, and the corrected target angular velocity ωt. The control device 7 sets the target rotational speed rt of each electric motor 25 based on the corrected target forward / backward velocity vt1, the corrected target left / right velocity vt2, and the corrected target angular velocity ωt. Furthermore, the control device 7 can control the current supplied to each electric motor 25 so that the rotational speed of each electric motor 25 becomes the target rotational speed.

[0079] The following describes an example of how the control device 7 controls the drive unit 4. First, the control device 7 sets a first rotational speed r1 of each electric motor 25 based on a modified target forward / backward speed vt1 by referring to a first mapping diagram. The first mapping diagram defines the relationship between the modified target forward / backward speed vt1 and the rotational speed of each electric motor 25. Next, the control device 7 sets a second rotational speed r2 of each electric motor 25 based on a modified target left / right speed vt2 by referring to a second mapping diagram. The second mapping diagram defines the relationship between the modified target left / right speed vt2 and the rotational speed of each electric motor 25. Next, the control device 7 sets a third rotational speed r3 of each electric motor 25 based on a modified target angular velocity ωt by referring to a third mapping diagram. The third mapping diagram defines the relationship between the modified target angular velocity ωt and the rotational speed of each electric motor 25. Next, the control device 7 calculates the target rotational speed rt (rt = r1 + r2 + r3) of each electric motor 25 by adding the first rotational speed r1, the second rotational speed r2, and the third rotational speed r3 of each electric motor 25. Furthermore, the control device 7 sets the current value It supplied to each electric motor 25 based on the target rotational speed rt of each electric motor 25 by referring to a fourth mapping diagram. The fourth mapping diagram defines the relationship between the target rotational speed rt and the current value It supplied to each electric motor 25.

[0080] According to the above implementation, corrections are made to decrease the target left-right velocity vt2 in response to the increase in the target angular velocity ωt. Therefore, even if the user applies an unintentional left-right load to the handle 5 during the rotation operation, the movement of the carriage 1 in the left-right direction can be suppressed. When the user pushes the carriage 1 from rear to front, if the user wants to turn the carriage 1 to the right, the user sometimes applies a leftward load to the handle 5 located at the rear 2A of the carriage 1. In the carriage 1 of this embodiment, corrections are made to decrease the target left-right velocity vt2 in response to the increase in the target angular velocity ωt. Therefore, the leftward target left-right velocity vt2 relative to the leftward load applied by the user is suppressed. Thus, as Figure 8 As shown in trajectory 50, the trolley 1 can turn appropriately to the right. On the other hand, in the comparative example where no correction is made to decrease the left-right velocity vt2 in response to the increase in the target angular velocity ωt, a relatively large left-right velocity vt2 is set relative to the left-right load applied by the user. Thus, as Figure 8 As shown in trajectory 51, the trolley 1 protrudes to the left while rotating to the right. Thus, according to this embodiment, a trolley 1 capable of suppressing sliding movement in the left and right directions during rotation can be provided.

[0081] The upper limit of the left and right speed, vt2u, is set to a value above the specified lower limit, vt2ul. Therefore, in response to the user's rotational operation, the trolley 1 moves slightly to the left or right. This allows the user's operating feel to closely approximate the response of the trolley 1.

[0082] Since the target's left and right velocities vt2 are corrected based on the corrected target angular velocity ωt, excessive decreases in the target's left and right velocities vt2 can be suppressed. As a result, the trolley 1 can generate a driving force that better matches the user's operating feel.

[0083] The above describes the specific implementation method, but the present invention is not limited to the described implementation method and can be widely modified. For example, various methods can be used to correct the target lateral velocity vt2 by the control device 7 in response to an increase in the target angular velocity ωt. For example, a coefficient can be set based on the target angular velocity ωt, and the target lateral velocity vt2 can be multiplied by the coefficient to correct the target lateral velocity vt2. The coefficient can, for example, decrease between 1 and 0 in response to an increase in the target angular velocity ωt.

[0084] In other embodiments, a sensor capable of detecting the front-to-back load, left-to-right load, and torque about the vertical axis applied to the handle 5 may be used instead of the force sensor 6. For example, the sensor may also be configured by combining multiple independent load sensors.

Claims

1. A trolley, comprising: Body; Omnidirectional wheels are provided on the left and right sides of the vehicle body, enabling the vehicle body to move in all directions along the floor surface; The left and right drive units drive each of the omnidirectional wheels; A handle is located on the vehicle body to receive user input. Sensors detect the front-to-back load, left-to-right load, and torque about the vertical axis applied to the handle; as well as The control device controls the drive unit based on the front-to-back load, the left-to-right load, and the torque about the vertical axis detected by the sensor. The control device is The target front-rear velocity of the vehicle body is set based on the front and rear loads, the target left-right velocity of the vehicle body is set based on the left and right loads, and the target angular velocity of the vehicle body about the vertical axis is set based on the torque about the vertical axis. The target's left and right velocities are corrected based on the target angular velocity, so that as the absolute value of the target angular velocity increases, the absolute values ​​of the target's left and right velocities become smaller. The drive unit is controlled based on the target's forward and backward velocity, the corrected left and right velocity, and the target's angular velocity. The control device corrects the target angular velocity so that the absolute value of the target angular velocity is below a predetermined upper limit value. The drive unit is controlled based on a modified target angular velocity instead of the target angular velocity.

2. The trolley according to claim 1, wherein... The control device sets upper limits for left and right velocities based on the target angular velocity. These upper limits are set such that the absolute value of the target angular velocity increases, and consequently, the absolute value of the upper limits for left and right velocities decreases. The target's left and right velocities are adjusted so that the absolute values ​​of the target's left and right velocities are below the upper limit of the left and right velocities.

3. The trolley according to claim 2, wherein the upper limit value of the left and right speed is set to a value above a predetermined lower limit value.

4. The trolley according to claim 3, wherein the upper limit of the left and right speed has a negative linear relationship with the target angular velocity in the region above the lower limit.

5. The trolley according to claim 1, wherein the control device corrects the target left and right speeds based on the correction value of the target angular velocity, such that the absolute value of the correction value of the target angular velocity increases, and the absolute value of the target left and right speeds becomes smaller.

6. The trolley according to any one of claims 1 to 4, wherein the control device corrects the target forward / backward speed so that the absolute value of the target forward / backward speed is below a predetermined upper limit value for forward / backward speed, and The drive unit is controlled based on a modified target forward / backward velocity instead of the target forward / backward velocity.

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