Mobile

Abstract

To provide a bogie which can perform a suitable revolving motion while preventing spinning.SOLUTION: A bogie 1 has: a vehicle body 2; a plurality of wheels 3; a drive unit 4 for driving each wheel; a handle 5 for receiving operation of a user; an input detection sensor 6 which detects a load and / or moment added to the handle; a rotation speed sensor 7 which detects each wheel rotation speed; and a control device 8 which sets get propulsion force to be outputted as propulsion force from each wheel on the basis of the load and / or moment, and controls the drive unit to output the target propulsion force as propulsion force. If a rotation speed of the wheel positioned on a side nearer to a center of revolution exceeds a prescribed threshold when revolving, the control device so sets the target propulsion force of the wheel positioned on a side far from the center of revolution as to be smaller the target propulsion force set on the basis of the load and / or moment.SELECTED DRAWING: Figure 7

Description

[Technical Field]

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

[0002] Patent Document 1 discloses a power-assist trolley having a handle for detecting the user's operating force and a power assist control means for driving the drive wheels for travel and steering based on the operating force input to the handle. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2004-114800 [Overview of the project] [Problems that the invention aims to solve]

[0004] In a trolley like the one described in Patent Document 1, if the forward and backward speed becomes too high during turning, the centrifugal force applied to the drive wheels increases. As a result, if the frictional force applied to the wheels located away from the center of rotation exceeds the maximum static friction force, those wheels will slip. This may cause the trolley to spin, beginning to rotate around a vertical axis that passes through its center of gravity.

[0005] In view of the above background, the object of the present invention is to provide a trolley that can perform appropriate turning movements while preventing spinning. [Means for solving the problem]

[0006] To solve the above problems, one aspect of the present invention provides a trolley (1) comprising: a body (2); a plurality of wheels (3) provided on the body; a drive unit (4) that drives each of the wheels; a handle (5) provided on the body that accepts user input; an input detection sensor (6) that detects the load and / or moment applied to the handle; a rotation speed sensor (7) that detects the rotation speed of each of the wheels; and a control device (8) that sets a target thrust force to be output as thrust force from each of the wheels based on the load and / or moment, and controls the drive unit to output the target thrust force as thrust force, wherein, when turning, if the rotation speed of the wheel located closer to the turning center exceeds a predetermined threshold, the control device sets the target thrust force of at least the wheel located further from the turning center to be smaller than the target thrust force set based on the load and / or moment.

[0007] In this embodiment, the thrust force of the wheels located on the side furthest from the center of rotation during a turn is set to be less than the target thrust force set based on the input load and / or moment. As a result, the trolley is decelerated, preventing the trolley from spinning and providing a trolley that can perform a proper turning motion.

[0008] In the above embodiment, preferably, the control device is configured to gradually decrease the target thrust of the wheel located on the side furthest from the pivot center over time.

[0009] According to this embodiment, it is possible to prevent the trolley from spinning and to prevent a sudden decrease in the propulsive force of the wheels.

[0010] In the above embodiment, preferably, the control device updates the target thrust of the wheel located on the side furthest from the pivot center by multiplying it by a predetermined value less than 1 at predetermined time intervals, thereby gradually decreasing the target thrust over time.

[0011] According to this embodiment, the propulsive force of the wheels can be gradually reduced by a simple method.

[0012] In the above embodiment, preferably, the threshold value differs depending on whether the wheels are arranged perpendicular to the turning direction or parallel to the turning direction.

[0013] According to this embodiment, a threshold can be set according to the direction of rotation.

[0014] In the above embodiment, preferably, the threshold value when the wheels are arranged perpendicular to the turning direction is greater than the threshold value when the wheels are arranged parallel to the turning direction.

[0015] When the wheels are arranged parallel to the turning direction, changing the turning radius by changing the thrust is not as easy as when the wheels are arranged perpendicular to the turning direction. In this embodiment, the threshold is set lower when the wheels are arranged parallel to the turning direction, where changing the turning radius is not easy, compared to when they are arranged perpendicularly. Therefore, when changing the turning radius is difficult, the thrust can be changed quickly.

[0016] In the above embodiment, preferably, the control device sets the target thrust force of the wheel located on the side furthest from the pivot center based on the load and / or moment obtained by multiplying the load and / or moment acquired by the input detection sensor by a predetermined first parameter of less than 1.

[0017] According to this embodiment, the thrust force of the wheels located on the side furthest from the center of rotation during a turn is set to be smaller than the target thrust force set based on the input load and / or moment, thereby preventing the bogie from spinning.

[0018] In the above aspect, preferably, the control device sets the target driving force of the wheel located closer to the turning center based on the load and / or the moment multiplied by a predetermined second parameter less than 1 with respect to the load and / or the moment acquired by the input detection sensor, and the first parameter and the second parameter are set to different values respectively.

[0019] According to this aspect, since the driving force of the carriage is set lower than the driving force set by the load and / or moment acquired by the input detection sensor, spinning of the carriage can be prevented.

[0020] In the above aspect, preferably, the first parameter is smaller than the second parameter.

[0021] According to this aspect, since the driving force of the wheel located farther from the turning center is set lower, spinning of the carriage can be effectively prevented.

[0022] In the above aspect, preferably, the wheel is an omnidirectional wheel that can be driven in the front-rear and left-right directions respectively, and the control device controls the drive unit to output the target driving force as the driving force in the front-rear direction, and sets the driving force in the left-right direction of the wheel located closer to the turning center in the same direction as the centrifugal force.

[0023] According to this aspect, the carriage is pushed in the direction away from the turning center, and the turning radius becomes larger, so spinning of the vehicle can be prevented.

[0024] In the above embodiment, preferably, the control device acquires the target speed and target angular velocity of the trolley based on the load and / or the moment, sets the target thrust force corresponding to the target speed and the target angular velocity, controls the drive unit to output the target thrust force as the thrust force, and when turning, if the rotational speed of the wheel located closer to the turning center exceeds the threshold, the control device sets the target speed to be lower than the target speed set based on the load and / or the moment.

[0025] In this embodiment, the target speed of the wheels located on the side furthest from the pivot center during turning is set lower than the target speed set based on the input load and / or moment. As a result, the trolley is decelerated, preventing spinning and providing a trolley that can perform proper turning maneuvers.

[0026] To solve the above problems, one aspect of the present invention provides a trolley (1) comprising: a body (2); a plurality of wheels (3) provided on the body; a drive unit (4) that drives each of the wheels; a handle (5) provided on the body that accepts user input; an input detection sensor (6) that detects the load and / or moment applied to the handle; a rotation speed sensor (7) that detects the rotation speed of each of the wheels; and a control device (8) that sets a target speed and target angular velocity of the trolley based on the load and / or moment, acquires the amount of drive of each of the wheels to drive the trolley at the target speed and target angular velocity, and controls the drive unit. The control device, when turning, acquires the amount of drive of at least the wheels located farther from the turning center based on a corrected target speed smaller than the target speed set based on the load and / or moment, and the target angular velocity, if the rotation speed of the wheel located closer to the turning center exceeds a predetermined threshold.

[0027] In this embodiment, the target speed of the wheels located on the side furthest from the pivot center during turning is set lower than the target speed set based on the input load and / or moment. As a result, the trolley is decelerated, preventing spinning and providing a trolley that can perform proper turning maneuvers. [Effects of the Invention]

[0028] With the above configuration, it is possible to provide a trolley that can perform appropriate turning movements while preventing spinning. [Brief explanation of the drawing]

[0029] [Figure 1] Perspective view of the trolley according to the present invention [Figure 2] Plan view of the trolley [Figure 3] Cross-sectional view of the omnidirectional wheel 3 [Figure 4] Side view of the main wheel [Figure 5] Block diagram showing the control device for the bogie. [Figure 6] A flowchart showing the drive process performed by the control device according to the first embodiment. [Figure 7] (A) Plan view and (B) Rear view to illustrate the position of the trolley during rotation. [Figure 8] A flowchart showing the correction process performed by the control device according to the second embodiment. [Figure 9] A flowchart showing the correction process performed by the control device according to the third embodiment. [Modes for carrying out the invention]

[0030] <<First Embodiment>> Hereinafter, an embodiment of the trolley according to the present invention will be described with reference to the drawings. Hereinafter, each direction will be defined with the trolley as the reference point.

[0031] As shown in Figure 1, the trolley 1 comprises a body 2, at least one omnidirectional wheel 3 mounted on the body 2 that moves the body 2 in all directions along the floor surface, a drive unit 4 that drives each of the omnidirectional wheels 3, a handle 5 mounted on the body 2 that receives user input, a force sensor 6 (an example of an input detection sensor) that detects the load applied to the handle 5, a rotation speed sensor 7 that acquires the rotation speed of the omnidirectional wheels 3, and a control device 8 that controls the drive unit 4 based on the load detected by each of the force sensors 6.

[0032] The vehicle body 2 extends in the front and rear directions. The rear part 2A of the vehicle body 2 extends upward above the front part 2B. The front part 2B of the vehicle body 2 is provided with a support base 11 for supporting other devices. The devices supported by the support base 11 include, for example, inspection equipment such as an X-ray scanner. The devices may be fastened to the support base 11. Inside the rear part 2A of the vehicle body 2, a control device 8, a battery, and various sensors may be provided.

[0033] In this embodiment, a pair of omnidirectional wheels 3 are provided at the lower part of the rear 2A of the vehicle body 2. In addition, left and right casters 13 are supported at the lower part of the front 2B of the vehicle body 2 via a suspension. The suspension is located below the vehicle body 2 and has arms 14 that extend to the left and right, and a spring 15 and a shock absorber 16 positioned between the vehicle body 2 and the arms 14. Each caster 13 is located below the left and right ends of the arms 14. Each caster 13 has a fork 13A that is rotatably coupled to the arm 14 about an axis that extends vertically, and a wheel 13B that is rotatably supported on the fork 13A about an axis that extends horizontally. The fork 13A rotates freely relative to the arm 14, and the wheel 13B rotates freely relative to the fork 13A.

[0034] As shown in Figure 2, the pair of omnidirectional wheels 3 are positioned with a gap between them to the left and right. In this embodiment, the pair of omnidirectional wheels 3 are positioned on the lower left and lower right of the rear 2A of the vehicle body 2. As shown in Figure 3, each omnidirectional wheel 3 has a frame 17, a pair of drive discs 18 rotatably supported by the frame 17, and an annular main wheel 19 positioned between the pair of drive discs 18.

[0035] As shown in Figures 1 and 3, the frame 17 has an upper frame 17A connected to the lower part of the vehicle body 2, and a pair of side frame portions 17B extending downward from both the left and right ends of the upper frame portion 17A. A support shaft 21 extending from left to right is spanned across the lower ends of the pair of side frame portions 17B. A pair of drive disks 18 are rotatably supported on the support shaft 21. The pair of drive disks 18 rotate about the axis Y1 of the support shaft 21. The position of each drive disk 18 in the left-right direction is restricted with respect to the support shaft 21. The drive disks 18 face each other at a distance in the left-right direction.

[0036] The drive disks 18 are positioned on either side of the annular main wheel 19, and apply frictional force to the main wheel 19, causing it to rotate around its central axis and annular axis. The drive disk 18 has a disc-shaped base 18A that is rotatably supported by the frame 17, and a plurality of drive rollers 18B that are rotatably supported on the outer circumference of the base 18A at an angle to each other and in contact with the main wheel 19. The base 18A is positioned coaxially with the support shaft 21.

[0037] Driven pulleys 18C are provided on opposite sides of each drive disk 18. The driven pulleys 18C are mounted coaxially with the drive disks 18. The drive unit 4 is located at the bottom of the vehicle body 2 and has a plurality of electric motors 25 corresponding to each drive disk 18. In this embodiment, four electric motors 25 are provided corresponding to four drive disks 18. A drive pulley 26 is provided on the output shaft of each electric motor 25. The corresponding drive pulleys 26 and driven pulleys 18C are connected by a belt 27. Each electric motor 25 rotates independently of each other, causing each drive disk 18 to rotate independently of each other.

[0038] As shown in Figure 4, the main wheel 19 is annular in shape, coaxially positioned between a pair of drive disks 18, in contact with a plurality of drive rollers 18B, and rotatable around a central axis and an annular axis. 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 in the circumferential direction of the core 31. Each driven roller 32 is rotatably supported on the annular core 31 about the axis A1 (annular axis) of the annular core 31. Each driven roller 32 can rotate about a tangent to the core 31 at its respective position relative to the core 31. Each driven roller 32 rotates relative to the core 31 when subjected to an external force.

[0039] The main wheel 19 is positioned along the outer circumference of a pair of drive disks 18 and is in contact with a plurality of drive rollers 18B provided on each drive disk 18. The drive rollers 18B of each drive disk 18 are in contact with the inner circumference of the main wheel 19, clamping the main wheel 19 from both the left and right sides. In addition, the drive rollers 18B of the left and right drive disks 18 restrict the radial displacement of the drive disks 18 around the axis Y1 by contacting the inner circumference of the main wheel 19. As a result, the main wheel 19 is supported by the left and right drive disks 18, and the central axis of the main wheel 19 (core body 31) is positioned coaxially with the axis Y1 of the left and right drive disks 18. The main wheel 19 is in contact with a plurality of drive rollers 18B of the left and right drive disks 18 at the plurality of driven rollers 32.

[0040] In each omnidirectional wheel 3, when a pair of drive discs 18 rotate in the same direction at the same rotational 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 coincides with the 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 body 31. In each omnidirectional wheel 3, when there is a difference in rotational speed between a pair of drive discs 18, a component force perpendicular 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. Because the axis of the drive roller 18B is inclined with respect to the circumferential direction of the drive roller 18B, a component force is generated between the drive discs 18 due to the difference in rotational speed. This component force causes the drive roller 18B to rotate relative to the base 18A, and the driven roller 32 to rotate relative to the core body 31. As a result, the main wheel 19 generates thrust in the left-right direction.

[0041] The trolley 1 moves forward as the left and right omnidirectional wheels 3 rotate forward at the same speed. The trolley 1 moves backward as the left and right omnidirectional wheels 3 rotate backward at the same speed. The trolley 1 turns to the right or left as there is a difference in the speed of rotation of the left and right omnidirectional wheels 3 in the forward and backward directions. The trolley 1 moves parallel to the right or left as the driven rollers 32 of each main wheel 19 of the left and right omnidirectional wheels 3 rotate.

[0042] As shown in Figures 1 and 2, a handle holder 35 protruding upward is provided on the upper part of the rear 2A of the vehicle body 2. The handle 5 is supported by the handle holder 35 via a force sensor 6. The force sensor 6 is preferably a three-axis force sensor that detects loads along two mutually orthogonal axes on the horizontal plane and a moment about the vertical axis (z axis). In this embodiment, the force sensor 6 detects a front-rear load (x axis), a load in the front-rear direction (x axis), a left-right load (y axis), and a moment about the vertical axis (z axis) applied to the handle 5. The force sensor 6 has a main body and an input unit provided on the main body. The main body is coupled to the handle holder 35.

[0043] The handle 5 has horizontal sections 5A extending to the left and right, and a pair of vertical sections 5B extending forward from both the left and right ends of the horizontal sections 5A. The central part of the horizontal section 5A in the left-right direction is connected to the input section of the force sensor 6.

[0044] As shown in Figure 2, when the user applies an external force fh and moment mhz to the position rh of the handle 5, the force sensor 6 detects a detected force fs and a detected moment msz at the sensor position rs. The detected force fs includes a longitudinal load fs1, which is the longitudinal component, and a lateral load fs2, which is the lateral component.

[0045] A rotation speed sensor 7 is provided for each omnidirectional wheel 3 and is supported by the vehicle body 2. The rotation speed sensor 7 detects the rotation speed of the corresponding omnidirectional wheel 3 around its axis Y1 (the number of times the omnidirectional wheel 3 rotates around its axis Y1 per unit time; also called rotational speed). However, the system is not limited to this configuration, and the rotation speed sensor 7 may also detect the rotation speed of the core body 31 of the omnidirectional wheel 3 around its axis Y1 and the rotation speed of the driven roller 32 around its axis A1.

[0046] The control unit 8 is an electronic control unit (ECU) that includes a processor such as a CPU and memory such as non-volatile memory (ROM) and volatile memory (RAM). The control unit 8 controls the drive unit 4 by executing arithmetic processing in accordance with a program stored in the non-volatile memory in the processor. The control unit 8 may be configured as a single piece of hardware or as a unit consisting of multiple pieces of hardware. Furthermore, at least a part of each functional part of the control unit 8 may be implemented by hardware such as an LSI, ASIC, FPGA, or by a combination of software and hardware.

[0047] As shown in Figure 5, the control device 8 is connected to the force sensor 6, the rotation speed sensor 7, and the drive unit 4. The force sensor 6 and the rotation speed sensor 7 output detection signals (detection results) to the control device 8. The control device 8 outputs control signals based on the signals from the force sensor 6 and the rotation speed sensor 7 to control the drive unit 4.

[0048] The force sensor 6 is interposed 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 8 determines the target longitudinal speed vt1, target lateral speed vt2, and target angular velocity ωt of the trolley 1 based on the signal from the force sensor 6, and determines the control amount of each electric motor 25 of the drive unit 4 based on the target longitudinal speed vt1, target lateral speed vt2, and target angular velocity ωt. Alternatively, the control device 8 may determine the control amount of each electric motor 25 based on the target propulsion force set for each omnidirectional wheel 3.

[0049] The control device 8 stores a predetermined counter in its memory. The counter is set to 0 when the trolley 1 is started. Hereafter, the value of the counter will be referred to as n.

[0050] While the trolley 1 is running, the control device 8 controls the drive unit 4 by performing the drive process shown in the flowchart of Figure 6 at predetermined intervals. The details of the drive process will be explained below with reference to Figure 6.

[0051] In the first step S1 of the drive process, the control device 8, based on the signal from the force sensor 6, determines the detected force f detected by the force sensor 6. s And obtain the detection moment msz. Detection force f s This includes the front-to-rear load fs1 and the left-to-right load fs2.

[0052] Once step S1 is completed, the control device 8 executes step S2. In step S2, the control device 8 sets the target longitudinal velocity vt1 of the vehicle body 2 based on the longitudinal load fs1, sets the target lateral velocity vt2 of the vehicle body 2 based on the lateral load fs2, and sets the target angular velocity ωt of the vehicle body 2 about the vertical axis based on the moment msz about the vertical axis. Hereafter, the velocity vector consisting of the target longitudinal velocity vt1 and the target lateral velocity vt2 will be referred to as the target velocity vt, as necessary.

[0053] When the longitudinal load fs1 is directed forward, the control device 8 sets the target longitudinal speed vt1 to be directed forward. In this embodiment, when the target longitudinal speed vt1 is directed forward, that is, when the trolley 1 is moving forward, the target longitudinal speed vt1 is set to be positive. Conversely, when the target longitudinal speed vt1 is directed backward, that is, when the trolley 1 is moving backward, the target longitudinal speed vt1 is set to be negative.

[0054] The target longitudinal speed vt1 may be set, for example, by multiplying the longitudinal load fs1 by a predetermined coefficient k1. Similarly, the target lateral speed vt2 may be set, for example, by multiplying the lateral load fs2 by a predetermined coefficient k2. Furthermore, the target angular velocity ωt may be set, for example, by multiplying the moment msz about the vertical axis by a predetermined coefficient k3. The target angular velocity ωt is set with respect to a reference point rc. The reference point rc may be set to a position that coincides with the center of gravity G of the trolley 1 in a plan view. In this embodiment, the reference point rc is located at the midpoint of the line segment connecting a pair of omnidirectional wheels 3. Note that the methods for setting the target longitudinal speed vt1, target lateral speed vt2, and target angular velocity ωt are not limited to these.

[0055] The lateral load fs2 applied by the worker moving the trolley 1 is sufficiently smaller than the front-to-back load fs1, or the coefficient k2 may be sufficiently smaller than the coefficients k1 and k3.

[0056] Once the control device 8 has completed setting the target longitudinal speed vt1, target lateral speed vt2, and target angular velocity ωt, it executes step S3. In step S3, the control device 8 calculates the target thrust F(i) that the left and right omnidirectional wheels 3 should output in order to output the target longitudinal speed vt1, target lateral speed vt2, and target angular velocity ωt, respectively. Here, i represents an argument (index) determined for each omnidirectional wheel 3, for example, i may be set to 1 for the left omnidirectional wheel 3 and 2 for the right omnidirectional wheel 3.

[0057] The target propulsion force F(i) may include the target rotational speed of the omnidirectional wheels 3 (core body 31) around their axis Y1. The target propulsion force F(i) may also include the target rotational speed of the driven rollers 32 around their axis A1. If there is a difference in the target rotational speeds of the left and right omnidirectional wheels 3 around their axis Y1, the trolley 1 will turn.

[0058] Next, once the calculation of the target thrust force F(i) is complete, the control device 8 executes step S4. In step S4, the control device 8 obtains the turning direction of the trolley 1 based on the target thrust force F(i). The control device 8 may also obtain the turning direction based on the difference in target rotational speeds around the axis Y1 of the left and right omnidirectional wheels 3. Alternatively, if the difference in target rotational speeds around the axis Y1 of the left and right omnidirectional wheels 3 is zero or less than or equal to a predetermined value, it may be determined that the trolley is moving straight (no turning direction).

[0059] Next, the control device 8 acquires the rotational speeds of the left and right omnidirectional wheels 3 around the axis Y1 detected by the rotational speed sensor 7. Then, the control device 8 determines whether the rotational speed around the axis Y1 detected by the rotational speed sensor 7 exceeds a predetermined rotational speed threshold for the omnidirectional wheels 3 that have a turning direction (i.e., are turning) and are located closer to the turning center. The control device 8 may also determine whether or not the vehicle is turning based on the difference in target rotational speeds around the axis Y1 of the left and right omnidirectional wheels 3.

[0060] When the trolley 1 is rotating and the rotational speed around axis Y1 detected by the omnidirectional wheels 3 located closer to the center of rotation exceeds the rotational speed threshold, the control device 8 performs step S5; otherwise, it performs step S6.

[0061] In step S5, the control device 8 updates the counter by adding 1 to the counter value, thereby updating it to n+1. Once the counter update is complete, the control device 8 executes step S7.

[0062] In step S7, the control device 8 performs a correction process. The correction process is a process to reduce the target thrust F(i) set in step S3 for the omnidirectional wheels 3 located on the side furthest from the center of rotation.

[0063] In this embodiment, the control device 8 first identifies an index i0 corresponding to the omnidirectional wheel 3 located on the side farther from the turning center, based on the turning direction acquired in step S4. Then, the control device 8 calculates the target thrust force F(i0) for the omnidirectional wheel 3 located on the side farther from the turning center by raising the target thrust force F(i0) obtained in step S3 to the power of n (α) by a predetermined value less than 1 (hereinafter referred to as the deceleration coefficient α). n The value obtained by multiplying the value of α raised to a power by (α n ×F(i0))(that is, α n The target thrust force F(i0) is corrected by updating it to the value obtained by multiplying it by α. As a result, the target thrust force F(i0) is corrected to the value obtained by multiplying it by α. n The product is corrected to the product of the two. However, at this time, the control device 8 may correct the target thrust force F(i0) by setting n to 1 and multiplying by the deceleration coefficient α (α × F(i0)). Once the correction is complete, the control device 8 executes step S8.

[0064] In step S6, the control device 8 changes the counter to 0 by substituting 0 for n, thereby resetting the counter. Once the counter reset is complete, the control device 8 executes step S8.

[0065] In step S8, the control device 8 sets the target rotational speed rt for each electric motor 25 based on the target thrust force F(i) set for each of the omnidirectional wheels 3. Then, in step S9, the control device 8 controls the current supplied to each electric motor 25 so that the rotational speed of each electric motor 25 reaches the target rotational speed, thereby controlling each electric motor 25.

[0066] Next, we will explain the effects of the trolley 1 configured in this way.

[0067] As shown in Figure 7(A), when the trolley 1 turns, centrifugal force can cause the vehicle body 2 to tilt outward in the direction of the turn, as shown in Figure 7(B). At this time, the omnidirectional wheels 3 located on the side of the turning center may lift off the floor, and the frictional force between these omnidirectional wheels 3 and the floor may decrease. The inventors of this application have found that this decrease in frictional force causes the omnidirectional wheels 3 located closer to the turning center to slip, spin freely, etc., and thus the rotational speed of the omnidirectional wheels 3 located closer to the turning center increases.

[0068] If the all-directional wheels 3 located closer to the pivot point slip or spin freely, the bogie 1 will primarily be driven by the all-directional wheels 3 located further from the pivot point. This will result in a smaller turning radius and a stronger centrifugal force. Consequently, the bogie 1 may end up spinning.

[0069] If the trolley 1 is turning and the rotation speed of the omnidirectional wheels 3 located closer to the turning center exceeds the rotation speed threshold (Yes in S4), the target thrust force F(i0) of the omnidirectional wheels 3 located further from the turning center during the turn is corrected to be less than the target thrust force F(i0) set in step S3 based on the input of load and / or moment (S7).

[0070] This correction reduces the thrust of the all-directional wheels 3 located farther from the pivot point, causing the bogie 1 to decelerate and increasing its turning radius. As a result, a bogie 1 can be provided that prevents spinning and allows for proper turning.

[0071] Furthermore, when the rotation speed of the omnidirectional wheels 3 located closer to the pivot center exceeds a rotation speed threshold (Yes in S4), a correction process is performed. Therefore, compared to the case where the rotation speed is based on the rotation speed of the omnidirectional wheels 3 located further from the pivot center, it is possible to quickly detect when the bogie 1 is transitioning to a spinning state, and thus effectively prevent the bogie 1 from spinning.

[0072] After the rotational speed of the omnidirectional wheel 3 located on the side closer to the turning center exceeds the rotational speed threshold value and this state is maintained, the counter is updated each time the drive process is performed. Therefore, each time the drive process is performed, the target propulsion force F(i0) is multiplied by the deceleration coefficient α. Thus, while the rotational speed of the omnidirectional wheel 3 located on the side closer to the turning center exceeds the rotational speed threshold value, the target propulsion force F(i0) output from the omnidirectional wheel 3 located on the side farther from the turning center gradually decreases over time.

[0073] Thus, while the rotational speed of the omnidirectional wheel 3 located on the side closer to the turning center exceeds the rotational speed threshold value, the counter increases, and the propulsion force output from the omnidirectional wheel 3 located on the side farther from the turning center gradually decreases over time. Therefore, it is possible to prevent the propulsion force output from the omnidirectional wheel 3 from suddenly decreasing. Also, the target propulsion force F(i0) obtained in step S3 is corrected by multiplying it by the value obtained by raising the deceleration coefficient α to the nth power (α n ). Thus, each time the drive process is performed, a value smaller than 1 is multiplied (multiplied) by the target propulsion force F(i0), so each time the drive process is performed, the target propulsion force F(i0) is updated to gradually decrease. In this way, by a simple method, the propulsion force output from the omnidirectional wheel 3 located on the side farther from the turning center can be gradually decreased.

[0074] <<Second Embodiment>> The carriage 1 according to the second embodiment differs in the correction process performed by the control device 8 in step S7 compared to the first embodiment, and since the other configurations are the same as those in the first embodiment, the description of the other configurations is omitted.

[0075] Hereinafter, the correction process of the carriage 1 according to the second embodiment will be described in detail with reference to the flowchart of FIG. 8.

[0076] The control device 8 uses the detected output f obtained in step S1 s ​​The first corrected detection force and first corrected detection moment are calculated by multiplying the detection moment msz by a predetermined first parameter B. That is, the control device 8 calculates the first corrected detection force as the detection force f s The first correction detection moment is calculated by the product of the detection moment msz and the first parameter B. The first parameter B may be set by a predetermined constant (hereinafter referred to as the first deceleration coefficient β) that is between 0 and 1. In addition, the first parameter B is the value obtained by raising the first deceleration coefficient β to the power of n, i.e., β n It may be set to that.

[0077] Once the calculation of the first corrected detection force and the first corrected detection moment is complete, the control device 8 executes step S12. In step S12, based on the first corrected detection force and the first corrected detection moment, the control device 8 calculates the target longitudinal velocity vt1 and target lateral velocity vt2, and the target angular velocity ωt, corresponding to the first corrected detection force and the first corrected detection moment, as the first corrected target longitudinal velocity, the first corrected target lateral velocity, and the first corrected target angular velocity, respectively, in the same manner as in step S2.

[0078] Once the calculation of the first corrected target longitudinal speed, first corrected target lateral speed, and first corrected target angular velocity is complete, the control device 8 executes step S13. In step S13, the control device 8 calculates the target thrust force F(i) for each of the all-direction wheels 3 corresponding to the first corrected target longitudinal speed, first corrected target lateral speed, and first corrected target angular velocity, as the first corrected target thrust force, similar to step S3.

[0079] Once the calculation of the first corrected target thrust force is complete, the control device 8 executes step S14. In step S14, the control device 8 detects the force f s The control device 8 calculates a second corrected detection force and a second corrected detection moment by multiplying each of the detection moments msz by a second parameter C, which is different from the first parameter B. That is, the control device 8 calculates the second corrected detection force as the detection force f sThe second correction detection moment is calculated by the product of the detection moment msz and the second parameter C.

[0080] The second parameter C may be set by a predetermined constant (hereinafter referred to as the second deceleration coefficient γ) that is greater than the first parameter B and is between 0 and 1. In this case, it is preferable that the second deceleration coefficient γ is set to a value greater than the first deceleration coefficient β, i.e., β < γ. The second parameter C is the value obtained by raising the second deceleration coefficient γ to the power of n, i.e., γ n It may be set to that.

[0081] Once the calculation of the second corrected detection force and the second corrected detection moment is complete, the control device 8 executes step S15. In step S15, based on the second corrected detection force and the second corrected detection moment, the control device 8 calculates the target longitudinal velocity vt1 and target lateral velocity vt2, and the target angular velocity ωt, corresponding to the second corrected detection force and the second corrected detection moment, as the second corrected target longitudinal velocity, the second corrected target lateral velocity, and the second corrected target angular velocity, respectively, in the same manner as in step S2.

[0082] Once the calculation of the second corrected target longitudinal speed, second corrected target lateral speed, and second corrected target angular velocity is complete, the control device 8 executes step S16. In step S16, the control device 8 calculates the target thrust force F(i) for each of the all-direction wheels 3 corresponding to the second corrected target longitudinal speed, second corrected target lateral speed, and second corrected target angular velocity as the second corrected target thrust force, similar to step S3.

[0083] Once the calculation of the second corrected target thrust force is complete, the control device 8 executes step S17. In step S17, the control device 8 sets the first corrected target thrust force of the omnidirectional wheels 3 located farther from the center of rotation as the target thrust force, and the second corrected target thrust force of the omnidirectional wheels 3 located closer to the center of rotation as the target thrust force. Once the setting is complete, the control device 8 finishes the correction process.

[0084] Next, we will explain the effects of the trolley 1 configured in this way.

[0085] The control device 8 obtains a first corrected target thrust force based on the first corrected detected force and first corrected detected moment obtained by multiplying the load and / or moment acquired by the force sensor 6 by a first parameter B of less than 1 (S11-S13), and sets the first corrected target thrust force to the thrust force of the omnidirectional wheels 3 located on the side furthest from the center of rotation (S17).

[0086] As a result, the thrust of the omnidirectional wheels 3 located on the side furthest from the center of rotation during a turn is set to be less than the thrust that is set based on the input load and / or moment, thus preventing the bogie 1 from spinning.

[0087] Furthermore, in this embodiment, the control device 8 obtains a second corrected target thrust force based on the second corrected detection force and second corrected detection moment obtained by multiplying the load and / or moment acquired by the force sensor 6 by a second parameter C of 1 or less (S14~S17), and sets the second corrected target thrust force as the thrust force of the omnidirectional wheels 3 located closer to the center of rotation (S17).

[0088] The first parameter B and the second parameter C are set to different values. Specifically, since the first deceleration coefficient β is smaller than the second deceleration coefficient γ (β < γ), the first parameter B is set to a smaller value than the second parameter C. The thrust force based on the first parameter B (first target thrust force) is set for the omnidirectional wheels 3 located closer to the turning center, and the thrust force based on the second parameter C (second target thrust force) is set for the omnidirectional wheels 3 located further away from the turning center. As a result, the thrust force for the omnidirectional wheels 3 located further away from the turning center is set lower, which effectively prevents the bogie 1 from spinning.

[0089] <<Third Embodiment>> The trolley 1 according to the third embodiment differs from the trolley 1 according to the first embodiment in the configuration of the correction process, but the other configurations are the same, so the other configurations will not be explained.

[0090] The correction process for the trolley 1 according to the third embodiment will be described in detail below with reference to the flowchart in Figure 9.

[0091] In the first step S21 of the correction process, the control device 8 calculates the first corrected target longitudinal speed and the first corrected target lateral speed by multiplying the target longitudinal speed and target lateral speed acquired in step S2 by the first parameter B, similar to that in the second embodiment. Hereinafter, the velocity vector consisting of the first corrected target longitudinal speed and the first corrected lateral speed will be referred to as the first corrected target speed. That is, in step S21, the control device 8 calculates the first corrected target speed by multiplying the target speed by the first parameter B. Once the calculation of the first corrected target speed is complete, the control device 8 executes step S22.

[0092] However, similar to the second embodiment, the first parameter B may be set by a first deceleration coefficient β which is a constant between 0 and 1. Alternatively, the first parameter B may be the value obtained by raising the first deceleration coefficient β, which is a constant between 0 and 1, to the power of n, i.e., β n It may be set to that.

[0093] In step S22, the control device 8 calculates the target thrust force F(i) for each of the omnidirectional wheels 3 corresponding to the first corrected target speed and target angular velocity, based on the first corrected target speed and target angular velocity, similar to step S3, as the first corrected target thrust force. Once the calculation of the first corrected target thrust force is complete, the control device 8 executes step S23.

[0094] In step S23, the control device 8 calculates the second corrected target longitudinal speed and the second corrected target lateral speed by multiplying the target longitudinal speed and target lateral speed acquired in step S2 by the second parameter C, similar to that of the second embodiment. That is, the control device 8 calculates the second corrected target longitudinal speed by the product of the target longitudinal speed and the second parameter C, and calculates the second corrected target lateral speed by the product of the target lateral speed and the second parameter C. Hereinafter, the velocity vector consisting of the second corrected target longitudinal speed and the second corrected lateral speed will be referred to as the second corrected target speed. That is, in step S23, the control device 8 calculates the second corrected target speed by multiplying the target speed by the second parameter C.

[0095] However, similar to the second embodiment, the second parameter C may be set by a second deceleration coefficient γ which is a constant between 0 and 1. Alternatively, the second parameter C may be the value obtained by raising the second deceleration coefficient γ, which is a constant between 0 and 1, to the power of n, i.e., γ n It may be set as follows: The first deceleration coefficient β is set to be smaller than the second deceleration coefficient γ, and the first parameter B is set to be smaller than the second parameter C. As a result, the first corrected target speed is set to be smaller than the second corrected target speed.

[0096] In step S24, the control device 8 calculates the target thrust force F(i) for each of the omnidirectional wheels 3 corresponding to the second corrected target speed and target angular velocity, based on the second corrected target speed and target angular velocity, similar to step S3, as the second corrected target thrust force. Once the calculation of the second corrected target thrust force is complete, the control device 8 executes step S25.

[0097] In step S25, the control device 8 sets the first corrected target thrust force of the omnidirectional wheels 3 located farther from the turning center to the target thrust force of the omnidirectional wheels 3 located farther from the turning center, and the second corrected target thrust force of the omnidirectional wheels 3 located closer to the turning center to the target thrust force of the omnidirectional wheels 3 located closer to the turning center. Once the settings are complete, the control device 8 finishes the correction process.

[0098] Next, we will explain the effects of the trolley 1 configured in this way.

[0099] When the control device 8 is turning, if the rotation speed of the omnidirectional wheels 3 located closer to the turning center exceeds a rotation speed threshold (Yes in S4), it calculates a first corrected target speed (S21) that is corrected to be smaller than the target speed set based on the load and / or moment, and corrects the target thrust force of the omnidirectional wheels 3 located further from the turning center based on the first corrected target speed (S25). As a result, the target thrust force of the omnidirectional wheels 3 located further from the turning center is set to be smaller than the target thrust force set based on the load and / or moment. Therefore, the trolley 1 is decelerated, preventing the trolley 1 from spinning, and providing a trolley 1 that can perform appropriate turning movements. Thus, the object of correction does not have to be the target thrust force; it can also be the target speed for obtaining the target thrust force.

[0100] At the same time, the control device 8 calculates a second corrected target speed that is smaller than the target speed set based on the load and / or moment (S23), and corrects the target thrust of the omnidirectional wheels 3 located closer to the turning center based on the second corrected target speed (S25). Since the first corrected target speed is smaller than the second corrected target speed, the thrust of the omnidirectional wheels 3 located further from the turning center is reduced by the correction to be less than the thrust of the omnidirectional wheels 3 located closer to the turning center. As a result, the bogie 1 is decelerated, the turning radius is widened, and the bogie 1 is prevented from spinning.

[0101] <<Variation>> In the above embodiment, the omnidirectional wheels 3 were arranged side by side on the vehicle body 2, but the embodiment is not limited to this configuration. The omnidirectional wheels 3 may also be arranged side by side on the vehicle body 2, front to back. However, when the omnidirectional wheels 3 are arranged side by side on the vehicle body 2, the rotation speed threshold is set to a larger value than when the omnidirectional wheels 3 are arranged side by side on the vehicle body 2.

[0102] When the omnidirectional wheels 3 are arranged parallel to the turning direction, changing the turning radius by changing the thrust of the omnidirectional wheels 3 is not as easy as when the omnidirectional wheels 3 are arranged perpendicular to the turning direction. Therefore, in the modified example, the threshold for when the omnidirectional wheels 3 are arranged parallel to the turning direction and changing the turning radius is not easy is set to be smaller than when they are arranged perpendicular to the turning direction. As a result, when changing the turning radius is difficult, the thrust is changed quickly, effectively preventing the bogie 1 from spinning.

[0103] In the third embodiment described above, when the control device 8 determines the control amount of each electric motor 25 of the drive unit 4 based on the target speed (target longitudinal speed vt1 and target lateral speed vt2) and target angular velocity ωt, steps S2, S22, and S24 may be omitted (i.e., the calculation of the target thrust force is omitted), and the control device 8 may be configured to perform steps S21 and S23 to correct the target speed. In this case, the control device 8 may set the target speed and target angular velocity for each of the left and right omnidirectional wheels 3 in step S2. Furthermore, in step S25, the control device 8 may correct the target speed of the omnidirectional wheel 3 located on the side farther from the turning center to the first corrected target speed, and correct the target speed of the omnidirectional wheel 3 located on the side closer to the turning center to the second corrected target speed. Subsequently, in step S8, the control device 8 may set the rotational speed of each of the omnidirectional wheels 3 based on the target speed and target angular velocity set for each of the omnidirectional wheels 3.

[0104] As a result, when the control device 8 turns, if the rotational speed of the omnidirectional wheels 3 located closer to the turning center exceeds a predetermined threshold, it acquires the drive amount (rotational speed) of the omnidirectional wheels 3 located further from the turning center based on a first corrected target speed and target angular velocity that are smaller than the target speed set based on the load and / or moment. Furthermore, the control device 8 acquires the drive amount (rotational speed) of the omnidirectional wheels 3 located closer to the turning center based on a second corrected target speed and target angular velocity that are smaller than the target speed set based on the load and / or moment. As a result, the trolley 1 is decelerated and the turning radius is widened compared to when the drive amount is calculated based on the target speed, thereby preventing the trolley 1 from spinning.

[0105] In the second and third embodiments described above, the first parameter B was configured to be smaller than (less than) the second parameter C. In the present invention, it is sufficient that at least the first parameter B is less than 1 and the second parameter C is set to 1 or less, and any configuration is acceptable as long as the target thrust set for the omnidirectional wheel 3 located on the side farther from the pivot center, and the target speed corresponding to that omnidirectional wheel 3, are set to be smaller than the target thrust and target speed set based on the load and / or the moment.

[0106] For example, the first parameter B and the second parameter C may each be set to a predetermined value less than 1. Alternatively, the first parameter B and the second parameter C may be set to be equal and less than 1. This reduces the rotation speed of all wheels 3 in all directions when spin is likely to occur, causing the bogie 1 to decelerate and thus preventing the bogie 1 from spinning.

[0107] This concludes the description of specific embodiments, but the present invention is not limited to the above embodiments and can be broadly modified and implemented.

[0108] In other embodiments, instead of the force sensor 6, sensors capable of detecting forward / backward loads, left / right loads, and moments around the vertical axis applied to the handle 5 may be used. For example, the sensors may be configured by combining a number of independent load sensors.

[0109] In the above embodiment, the trolley 1 was equipped with omnidirectional wheels 3, but the embodiment is not limited to this. Any embodiment in which the trolley 1 is equipped with a pair of left and right wheels that can be driven based on a target longitudinal speed and a target angular speed, instead of the omnidirectional wheels 3, is acceptable.

[0110] In the above embodiment, the control device 8 was configured to consider that slippage (spin) may occur in the trolley 1 when the rotation speed of the omnidirectional wheel 3 located closer to the pivot center exceeded a rotation speed threshold, and to correct the target propulsion force. However, the method by which the control device 8 detects slippage in the trolley 1 is not limited to the method of the above embodiment. For example, if the trolley 1 is equipped with omnidirectional wheels 3 arranged on the left and right sides, and speed sensors that detect the left and right speeds of each omnidirectional wheel 3, the control device 8 may calculate the difference in left and right speeds of the left and right omnidirectional wheels 3 based on the detection results from the speed sensors, and determine that slippage (slippage) of the trolley 1 may occur when the calculated difference (absolute value) of left and right speeds exceeds a predetermined threshold. [Explanation of symbols]

[0111] 1: Dolly 2: Vehicle body 3: Omnidirectional wheels (an example of wheels) 4: Drive Unit 5: Handle 6: Force sensor (an example of an input detection sensor) 7: Rotation speed sensor 8: Control device

Claims

1. A moving body, The car body and A plurality of wheels provided on the vehicle body; a drive unit for driving each of the wheels; an operation unit provided on the vehicle body and configured to receive operations from a user; an input detection sensor that detects a load and / or a moment applied to the operation unit; a rotation speed sensor for detecting the rotation speed of each of the wheels; a control device that sets a target thrust to be output as thrust from each of the wheels based on the load and / or the moment, and controls the drive units to output the target thrust as the thrust, The control device, when turning, sets the target propulsive force of at least the wheel located farther from the turning center to be smaller than the target propulsive force set based on the load and / or the moment when the rotation speed of the wheel located closer to the turning center exceeds a predetermined threshold.

2. 2. The moving body according to claim 1, wherein the control device sets the target thrust of the wheel located farther from the turning center so as to gradually decrease with time.

3. 3. The vehicle according to claim 2, wherein the control device updates the target thrust of the wheel located farther from the turning center by multiplying the target thrust by a predetermined numerical value less than 1 at predetermined time intervals, and gradually reduces the target thrust over time.

4. The vehicle according to any one of claims 1 to 3, wherein the threshold value is different when the wheels are arranged in a direction perpendicular to the turning direction from when the wheels are arranged in a direction parallel to the turning direction.

5. 5. The moving body according to claim 4, wherein the threshold value when the wheels are arranged in a direction perpendicular to the turning direction is greater than the threshold value when the wheels are arranged in parallel to the turning direction.

6. 2. The mobile body according to claim 1, wherein the control device sets the target propulsive force of the wheel located farther from the turning center based on the load and / or the moment obtained by multiplying the load and / or the moment acquired by the input detection sensor by a predetermined first parameter less than 1.

7. The control device setting the target thrust of the wheel located closer to the turning center based on the load and / or the moment obtained by multiplying the load and / or the moment acquired by the input detection sensor by a predetermined second parameter that is less than 1; The moving body according to claim 6 , wherein the first parameter and the second parameter are set to different values.

8. The moving body according to claim 7 , wherein the first parameter is smaller than the second parameter.

9. The wheels are omnidirectional wheels that can be driven in both forward and backward directions and left and right directions, The vehicle described in any one of claims 1 to 3, wherein the control device controls the drive unit to output the target propulsive force as the propulsive force in the forward / backward direction, and sets the propulsive force in the left / right direction of the wheel located closer to the turning center to the same direction as the centrifugal force.

10. the control device acquires a target speed and a target angular speed of the moving body based on the load and / or the moment, sets the target thrust corresponding to the target speed and the target angular speed, and controls the drive unit to output the target thrust as the thrust; 2. The mobile body according to claim 1, wherein, when the rotation speed of the wheel located closer to the turning center exceeds the threshold value during turning, the control device sets the target speed to be smaller than the target speed set based on the load and / or the moment.

11. A moving body, The car body and A plurality of wheels provided on the vehicle body; a drive unit for driving each of the wheels; an operation unit provided on the vehicle body and configured to receive operations from a user; an input detection sensor that detects a load and / or a moment applied to the operation unit; a rotation speed sensor for detecting the rotation speed of each of the wheels; a control device that sets a target speed and a target angular velocity of the moving body based on the load and / or the moment, acquires a drive amount for each of the wheels, and controls the drive unit so that the moving body travels at the target speed and the target angular velocity, When the rotation speed of the wheel located closer to the turning center exceeds a predetermined threshold value during turning, the control device obtains the drive amount of at least the wheel located farther from the turning center based on a corrected target speed that is smaller than the target speed set based on the load and / or the moment, and the target angular velocity.

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