Automated guided vehicles

Abstract

To provide an unmanned carrier capable of suppressing postural change of a carrier body in switching between a normal travel mode and a sideward travel mode.SOLUTION: An unmanned carrier capable of switching between a normal travel mode in which it can travel straight in a front-rear direction X and a sideward travel mode in which it can travel straight in a right-left direction Y comprises: a plurality of wheels (a left front wheel 3FL and a right front wheel 3FR, and a left rear wheel 3RL and a right rear wheel 3RR); a drive unit which limits rolling of the left front wheel 3FL and left rear wheel 3RL; a steering device which change directions of the plurality of wheels; and a control device. In the switching between the normal travel mode and sideward travel mode, the control device controls the steering device to change the directions of the right front wheel 3FR and left rear wheel 3RL after changing the directions of the left front wheel 3FL and right rear wheel 3RR, and also controls the drive unit to limit rolling of the left rear wheel 3RL when changing the direction of the left front wheel 3FL and right rear wheel 3RR and limit rolling of the left front wheel 3FL when changing the direction of the right front wheel 3FR and left rear wheel 3RL.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present invention relates to an automated guided vehicle that can switch between a normal driving mode and a lateral driving mode.

Background Art

[0002] An automated guided vehicle that can switch between a normal driving mode in which it can drive straight in the front-rear direction and a lateral driving mode in which it can drive straight in the left-right direction is known (see, for example, Patent Document 1). The switching between the normal driving mode and the lateral driving mode is performed by changing the direction of the wheels.

[0003] FIG. 8 illustrates a conventional automated guided vehicle including a vehicle body 102 and a plurality of wheels 103. As shown in FIG. 8(A), in the automated guided vehicle in the normal driving mode, the wheels 103 are oriented in the front-rear direction X. When switching from the normal driving mode to the lateral driving mode, as shown in FIG. 8(B), a steering device (not shown) changes the direction of the wheels 103 so that the wheels 103 are oriented in the left-right direction Y. At this time, due to the unevenness of the road surface and the grounding state of the wheels 103, there is a problem that the posture of the vehicle body 102 changes as shown in FIG. 8(C). Therefore, as described in Patent Document 1, correcting the posture change of the vehicle body during driving has been performed.

[0004] However, when correcting the posture change of the vehicle body during driving, if the distance from when starting to drive after switching between the normal driving mode and the lateral driving mode to when stopping is short, there is a problem that the posture change of the vehicle body cannot be sufficiently corrected.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] The present invention has been made in view of the above circumstances, and aims to provide an automated guided vehicle that can suppress changes in the vehicle's posture when switching between a normal driving mode and a traversing mode. [Means for solving the problem]

[0007] To solve the above problems, the present invention provides an automated guided vehicle (AGV) capable of switching between a normal driving mode that allows straight-line driving in the longitudinal direction and a traverse mode that allows straight-line driving in the left-right direction, comprising a plurality of wheels spaced apart in the longitudinal and left-right directions, a braking device that restricts the rolling of at least two of the wheels, a steering device that changes the direction of the plurality of wheels, and a control device that controls the braking device and the steering device, wherein the control device controls the steering device so that when switching between the normal driving mode and the traverse mode, it changes the direction of the primary steering wheels first and then the direction of the secondary steering wheels, and further controls the braking device so that when changing the direction of the primary steering wheels it restricts the rolling of at least one of the wheels included in the secondary steering wheels, and when changing the direction of the secondary steering wheels it restricts the rolling of at least one of the wheels included in the primary steering wheels.

[0008] Furthermore, the vehicle is equipped with front and rear wheels spaced apart in the front-rear direction, the front wheels consist of a left front wheel and a right front wheel spaced apart in the left-right direction, and the rear wheels consist of a left rear wheel and a right rear wheel spaced apart in the left-right direction. Preferably, one of the pair of the left front wheel and the right rear wheel, and the pair of the right front wheel and the left rear wheel, is a primary steering wheel and the other is a secondary steering wheel.

[0009] Furthermore, it is preferable that the rolling of any one of the following pairs—the left front wheel and the left rear wheel, the right front wheel and the right rear wheel, the left front wheel and the right front wheel, and the left rear wheel and the right rear wheel—is restricted by the braking device.

[0010] Furthermore, the vehicle is equipped with front and rear wheels spaced apart in the front-rear direction, the front wheels consist of a left front wheel and a right front wheel spaced apart in the left-right direction, and the rear wheels consist of a left rear wheel and a right rear wheel spaced apart in the left-right direction. Preferably, one pair of the left front wheel and the left rear wheel, one pair of the right front wheel and the right rear wheel, one pair of the left front wheel and the right front wheel, or one pair of the left rear wheel and the right rear wheel are primary steering wheels.

[0011] Furthermore, it is preferable that the rolling of one of the pairs of the left front wheel and the right rear wheel, or the pair of the right front wheel and the left rear wheel, is restricted by the braking device. [Effects of the Invention]

[0012] According to the present invention, it is possible to provide an automated guided vehicle that can suppress changes in the vehicle's posture when switching between a normal driving mode and a traversing mode. [Brief explanation of the drawing]

[0013] [Figure 1] This is a schematic diagram of an automated guided vehicle according to one embodiment of the present invention. [Figure 2] This is a block diagram showing the schematic configuration of an automated guided vehicle according to the same embodiment. [Figure 3] This flowchart shows the flow of the driving mode switching process according to the same embodiment. [Figure 4] (A) to (D) are schematic diagrams illustrating the operation of the automated guided vehicle according to the same embodiment. [Figure 5] (A) to (D) are schematic diagrams illustrating the operation of the automated guided vehicle in the modified form. [Figure 6] (A) to (D) are schematic diagrams illustrating the operation of the automated guided vehicle in the modified form. [Figure 7] (A) to (D) are schematic diagrams illustrating the operation of the automated guided vehicle in the modified form. [Figure 8](A) to (C) are schematic diagrams illustrating the operation of an automated guided vehicle (AGV) in a conventional example. [Modes for carrying out the invention]

[0014] An embodiment of the present invention will be described with reference to Figures 1 to 4. As shown in Figure 1, the automated guided vehicle 1 according to this embodiment comprises a vehicle body 2, front wheels 3F and rear wheels 3R, guidance sensors 4F and 4R for the normal driving mode, and guidance sensors 5L and 5R for the traverse driving mode. The automated guided vehicle 1 operates by switching between a normal driving mode in which it can travel in a straight line in the forward / backward direction X, and a traverse mode in which it can travel in a straight line in the left / right direction Y.

[0015] The vehicle body 2 is equipped with a cargo platform (not shown) that has a transfer device. The transfer device consists of, for example, a belt conveyor or roller conveyor driven by a cargo handling motor and is controlled by a control device 8 (see Figure 2), which will be described later.

[0016] The front wheels 3F and rear wheels 3R ​​are spaced apart in the longitudinal direction X. The front wheels 3F consist of the left front wheel 3FL and the right front wheel 3FR, which are spaced apart in the lateral direction Y. The rear wheels 3R ​​consist of the left rear wheel 3RL and the right rear wheel 3RR, which are spaced apart in the lateral direction Y. In this embodiment, the left front wheel 3FL and the left rear wheel 3RL are drive wheels that roll when the driving force for the automated guided vehicle 1 to travel is transmitted to them, and the right front wheel 3FR and the right rear wheel 3RR are driven wheels that roll in conjunction with the rolling of the left front wheel 3FL and the left rear wheel 3RL. When the left front wheel 3FL, the right front wheel 3FR, the left rear wheel 3RL, and the right rear wheel 3RR (hereinafter collectively referred to as "the four wheels") are facing in the longitudinal direction X, the automated guided vehicle 1 is in normal travel mode, and when the four wheels are facing in the lateral direction Y, the automated guided vehicle 1 is in lateral travel mode. Each of the four wheels is configured to rotate around an axis A that is perpendicular to the longitudinal direction X and the lateral direction Y.

[0017] The guiding sensors 4F and 4R are provided at intervals in the longitudinal direction X. When the driverless transport vehicle 1 travels in the normal driving mode, the guiding sensors 4F and 4R detect a guiding line LX provided on the road surface so as to extend in the longitudinal direction X, and output the detection result to a control device 8 (see FIG. 2) described later.

[0018] The guiding sensors 5L and 5R are provided at intervals in the lateral direction Y. When the driverless transport vehicle 1 travels in the lateral movement mode, the guiding sensors 5L and 5R detect a guiding line LY provided on the road surface so as to extend in the lateral direction Y, and output the detection result to a control device 8 (see FIG. 2) described later.

[0019] Also, as shown in FIG. 2, the driverless transport vehicle 1 includes drive units 6FL and 6RL (hereinafter collectively referred to as "drive unit 6"), steering devices 7FL, 7FR, 7RL, and 7RR (hereinafter collectively referred to as "steering device 7"), and a control device 8.

[0020] The drive unit 6 is composed of a traveling motor with a brake. The drive unit 6 functions as a driving device for driving drive wheels by operating the traveling motor, and also functions as a braking device for restricting the rolling of the drive wheels by operating the brake of the traveling motor. The drive unit 6FL is a driving device and a braking device for the left front wheel 3FL, and the drive unit 6RL is a driving device and a braking device for the left rear wheel 3RL.

[0021] The steering device 7 is composed of a steering motor with a potentiometer. The steering device 7 changes the direction (steering angle) of the wheels by rotating the wheels around an axis A (see FIG. 1). The steering device 7FL changes the direction of the left front wheel 3FL, the steering device 7FR changes the direction of the right front wheel 3FR, the steering device 7RL changes the direction of the left rear wheel 3RL, and the steering device 7RR changes the direction of the right rear wheel 3RR.

[0022] The control device 8 consists of a programmable logic controller and a motor driver. When the automated guided vehicle 1 is in normal travel mode, the control device 8 controls the drive unit 6 and steering device 7 so that it travels along the guide line LX detected by the guide sensors 4F and 4R, and when the automated guided vehicle 1 is in traverse mode, the control device 8 controls the drive unit 6 and steering device 7 so that it travels along the guide line LY detected by the guide sensors 5L and 5R.

[0023] Furthermore, the control device 8 controls the drive unit 6 and the steering device 7 to perform a driving mode switching process when switching from normal driving mode to traverse mode, and when switching from traverse mode to normal driving mode. In the driving mode switching process, the control device 8 controls the steering device 7 so that one pair of wheels out of the four wheels (multiple wheels) is designated as primary steering wheels and the other pair of wheels as secondary steering wheels, and changes the direction of the primary steering wheels first, and then changes the direction of the secondary steering wheels. In this embodiment, the control device 8 designates the left front wheel 3FL and the right rear wheel 3RR as primary steering wheels, and the right front wheel 3FR and the left rear wheel 3RL as secondary steering wheels, and controls the steering devices 7FL and 7RR first, and then controls the steering devices 7FR and 7RL.

[0024] Furthermore, the control device 8 restricts the rolling of at least one wheel included in the secondary steering wheels when changing the direction of the primary steering wheels, and controls the drive unit 6 to restrict the rolling of at least one wheel included in the primary steering wheels when changing the direction of the secondary steering wheels. In this embodiment, the control device 8 controls the drive unit 6RL to restrict the rolling of the left rear wheel 3RL when changing the direction of the left front wheel 3FL and the right rear wheel 3RR, and controls the drive unit 6FL to restrict the rolling of the left front wheel 3FL when changing the direction of the right front wheel 3FR and the left rear wheel 3RL.

[0025] Referring to Figure 3, the flow of the driving mode switching process for switching between the normal driving mode and the traversing mode will be explained in detail. Note that the driving mode switching process is started when the automated guided vehicle 1 is stopped moving.

[0026] First, the control device 8 releases the brake on the drive wheel included in the primary steering wheel (step S1). In this embodiment, the control device 8 releases the brake on the left front wheel 3FL by releasing the brake on the drive unit 6FL.

[0027] Next, the control device 8 changes the orientation of the primary steering wheels so that the steering angle of the primary steering wheels changes by 90 degrees (step S2). In this embodiment, the control device 8 changes the orientation of the left front wheel 3FL and the right rear wheel 3RR by operating the steering devices 7FL and 7RR so that the steering angles of the left front wheel 3FL and the right rear wheel 3RR change by 90 degrees.

[0028] Next, the control device 8 restricts the rolling of the drive wheels included in the primary steering wheels (step S3) and releases the brakes on the drive wheels included in the secondary steering wheels (step S4). In this embodiment, the control device 8 restricts the rolling of the left front wheel 3FL by operating the brake of the drive unit 6FL, and releases the brakes on the left rear wheel 3RL by releasing the brake of the drive unit 6RL.

[0029] Next, the control device 8 changes the direction of the secondary steering wheels so that the steering angle of the secondary steering wheels changes by 90 degrees (step S5). In this embodiment, the control device 8 changes the direction of the right front wheel 3FR and the left rear wheel 3RL by operating the steering devices 7FR and 7RL so that the steering angles of the right front wheel 3FR and the left rear wheel 3RL change by 90 degrees.

[0030] Then, the control device 8 restricts the rolling of the drive wheels included in the secondary steering wheels (step S6). In this embodiment, the control device 8 restricts the rolling of the left rear wheel 3RL by operating the brake of the drive unit 6RL.

[0031] Referring to Figure 4, the changes in the orientation of the front wheels 3F and rear wheels 3R ​​when switching from normal driving mode to traverse mode will be explained. In Figure 4, wheels with restricted rolling are shown with thicker lines compared to wheels with unrestricted rolling.

[0032] As shown in Figure 4(A), before switching from normal driving mode to traverse mode, the drive units 6FL and 6RL apply the brakes, restricting the rolling of the left front wheel 3FL and left rear wheel 3RL so that the automated guided vehicle 1 stops moving. However, if the automated guided vehicle 1 has stopped moving, the driving mode switching process may start without restricting the rolling of the left front wheel 3FL and left rear wheel 3RL.

[0033] Next, as shown in Figure 4(B), the steering units 7FL and 7RR change the direction of the left front wheel 3FL and the right rear wheel 3RR, so that the left front wheel 3FL and the right rear wheel 3RR face the left-right direction Y. At this time, the drive unit 6FL releases the brake, releasing the restriction on the rolling of the left front wheel 3FL, and the drive unit 6RL applies the brake, restricting the rolling of the left rear wheel 3RL. Therefore, displacement of the vehicle body 2 in the longitudinal direction X is suppressed by the left rear wheel 3RL, and displacement of the vehicle body 2 in the left-right direction Y is suppressed by the right front wheel 3FR and the left rear wheel 3RL.

[0034] Next, as shown in Figure 4(C), the steering units 7FR and 7RL change the direction of the right front wheel 3FR and the left rear wheel 3RL, causing the right front wheel 3FR and the left rear wheel 3RL to also face the left-right direction Y. At this time, the drive unit 6RL releases the brake, releasing the restriction on the rolling of the left rear wheel 3RL, and the drive unit 6FL applies the brake, restricting the rolling of the left front wheel 3FL. Therefore, displacement of the vehicle body 2 in the longitudinal direction X is suppressed by the left front wheel 3FL and the right rear wheel 3RR, and displacement of the vehicle body 2 in the left-right direction Y is suppressed by the left front wheel 3FL.

[0035] Then, as shown in Figure 4(D), after switching from normal driving mode to traverse mode, the drive units 6FL and 6RL apply the brakes, restricting the rolling of the left front wheel 3FL and left rear wheel 3RL until the automated guided vehicle 1 starts moving. However, the automated guided vehicle 1 may start moving after switching from normal driving mode to traverse mode without restricting the rolling of the left front wheel 3FL and left rear wheel 3RL.

[0036] In this embodiment, the following effects can be obtained. (1) The control device 8 controls the steering device 7 so that when switching between normal driving mode and traverse mode, it changes the direction of the primary steering wheels first, and then the direction of the secondary steering wheels, with the left front wheel 3FL and the right rear wheel 3RR as primary steering wheels and the right front wheel 3FR and the left rear wheel 3RL as secondary steering wheels. Furthermore, the control device 8 controls the drive unit 6 (braking device) so that when changing the direction of the primary steering wheels, it restricts the rolling of the left rear wheel 3RL which is included in the secondary steering wheels, and when changing the direction of the secondary steering wheels, it restricts the rolling of the left front wheel 3FL which is included in the primary steering wheels. With this configuration, when changing the direction of the primary steering wheels, the change in the attitude of the vehicle body 2 is suppressed because the secondary steering wheels, including the left rear wheel 3RL whose rolling is restricted, do not move, and when changing the direction of the secondary steering wheels, the change in the attitude of the vehicle body 2 is suppressed because the primary steering wheels, including the left front wheel 3FL whose rolling is restricted, do not move. Therefore, the change in the attitude of the vehicle body 2 can be suppressed when switching between normal driving mode and traverse mode.

[0037] (2) The left front wheel 3FL and the right rear wheel 3RR are the primary steering wheels, and the right front wheel 3FR and the left rear wheel 3RL are the secondary steering wheels. Therefore, by simultaneously changing the direction of the pair of front wheels 3F and rear wheels 3R, which are positioned at a distance from each other, changes in the attitude of the vehicle body 2 can be further suppressed.

[0038] The present invention is not limited to the embodiments described above, and the above configuration can be modified. For example, it can be implemented with the following modifications, or a combination of the following modifications can be used.

[0039] The right front wheel 3FR and the left rear wheel 3RL may be designated as primary steering wheels, and the left front wheel 3FL and the right rear wheel 3RR may be designated as secondary steering wheels. In this case, the control device 8 controls the drive unit 6 to restrict the rolling of the left front wheel 3FL, which is included in the secondary steering wheels, when changing the direction of the primary steering wheels, and to restrict the rolling of the left rear wheel 3RL, which is included in the primary steering wheels, when changing the direction of the secondary steering wheels.

[0040] By changing the configuration of the drive unit 6, the right front wheel 3FR and the right rear wheel 3RR may be made into drive wheels, and the left front wheel 3FL and the left rear wheel 3RL may be made into driven wheels. In other words, the rolling of the right front wheel 3FR and the right rear wheel 3RR may be limited by the braking device.

[0041] By changing the configuration of the drive unit 6, one of the front wheels 3F and the rear wheels 3R ​​may be made a drive wheel and the other a driven wheel. In other words, the rolling of the left front wheel 3FL and the right front wheel 3FR, or the rolling of the left rear wheel 3RL and the right rear wheel 3RR may be restricted by the braking device.

[0042] Referring to Figure 5, the changes in the orientation of the front wheels 3F and rear wheels 3R ​​when switching from normal driving mode to traverse mode in a configuration where the rolling of the left front wheel 3FL and the right front wheel 3FR is restricted will be explained.

[0043] As shown in Figure 5(A), the rolling of the left front wheel 3FL and the right front wheel 3FR is restricted so that the automated guided vehicle 1 stops moving before switching from the normal driving mode to the traversing mode.

[0044] Next, as shown in Figure 5(B), the steering devices 7FL and 7RR change the direction of the left front wheel 3FL and the right rear wheel 3RR, so that the left front wheel 3FL and the right rear wheel 3RR face the left-right direction Y. At this time, the restriction on the rolling of the left front wheel 3FL is released, and the rolling of the right front wheel 3FR is restricted. Therefore, displacement of the vehicle body 2 in the longitudinal direction X is suppressed by the right front wheel 3FR, and displacement of the vehicle body 2 in the left-right direction Y is suppressed by the right front wheel 3FR and the left rear wheel 3RL.

[0045] Next, as shown in Figure 5(C), the steering devices 7FR and 7RL change the direction of the right front wheel 3FR and the left rear wheel 3RL, causing the right front wheel 3FR and the left rear wheel 3RL to also face the left-right direction Y. At this time, the restriction on the rolling of the right front wheel 3FR is released, and the rolling of the left front wheel 3FL is restricted. Therefore, displacement of the vehicle body 2 in the longitudinal direction X is suppressed by the left front wheel 3FL and the right rear wheel 3RR, and displacement of the vehicle body 2 in the left-right direction Y is suppressed by the left front wheel 3FL.

[0046] Then, as shown in Figure 5(D), after switching from normal driving mode to traverse mode, the rolling of the left front wheel 3FL and the right front wheel 3FR is restricted until the automated guided vehicle 1 starts moving.

[0047] By changing the configuration of the drive unit 6, one of the pairs of the left front wheel 3FL and the right rear wheel 3RR, or the right front wheel 3FR and the left rear wheel 3RL, may be configured as a drive wheel and the other as a driven wheel. In other words, the rolling of the left front wheel 3FL and the right rear wheel 3RR, or the rolling of the right front wheel 3FR and the left rear wheel 3RL, may be restricted by the braking device.

[0048] Referring to Figure 6, the change in orientation of the front wheel 3F and rear wheel 3R when switching from normal driving mode to traverse mode will be explained in a configuration where the left front wheel 3FL and right rear wheel 3RR are drive wheels, and the left front wheel 3FL and left rear wheel 3RL are primary steering wheels.

[0049] As shown in Figure 6(A), the rolling of the left front wheel 3FL and the right rear wheel 3RR is restricted so that the automated guided vehicle 1 stops moving before switching from the normal driving mode to the traversing mode.

[0050] Next, as shown in Figure 6(B), the steering devices 7FL and 7RL change the direction of the left front wheel 3FL and the left rear wheel 3RL, so that the left front wheel 3FL and the left rear wheel 3RL face the left-right direction Y. At this time, the restriction on the rolling of the left front wheel 3FL is released, and the rolling of the right rear wheel 3RR is restricted. Therefore, displacement of the vehicle body 2 in the longitudinal direction X is suppressed by the right rear wheel 3RR, and displacement of the vehicle body 2 in the left-right direction Y is suppressed by the right front wheel 3FR and the right rear wheel 3RR.

[0051] Next, as shown in Figure 6(C), the steering devices 7FR and 7RR change the direction of the right front wheel 3FR and the right rear wheel 3RR, causing the right front wheel 3FR and the right rear wheel 3RR to also face the left-right direction Y. At this time, the restriction on the rolling of the right rear wheel 3RR is released, and the rolling of the left front wheel 3FL is restricted. Therefore, displacement of the vehicle body 2 in the longitudinal direction X is suppressed by the left front wheel 3FL and the left rear wheel 3RL, and displacement of the vehicle body 2 in the left-right direction Y is suppressed by the left front wheel 3FL.

[0052] Then, as shown in Figure 6(D), after switching from normal driving mode to traverse mode, the rolling of the left front wheel 3FL and the right rear wheel 3RR is restricted until the automated guided vehicle 1 starts moving.

[0053] Furthermore, referring to Figure 7, we will explain the change in orientation of the front wheel 3F and rear wheel 3R when switching from normal driving mode to traverse mode, in a configuration where the left front wheel 3FL and the right rear wheel 3RR are drive wheels and the front wheel 3F is the primary steering wheel.

[0054] As shown in Figure 7(A), the rolling of the left front wheel 3FL and the right rear wheel 3RR is restricted so that the automated guided vehicle 1 stops moving before switching from the normal driving mode to the traversing mode.

[0055] Next, as shown in Figure 7(B), the steering devices 7FL and 7FR change the orientation of the left front wheel 3FL and the right front wheel 3FR, so that the left front wheel 3FL and the right front wheel 3FR face the left-right direction Y. At this time, the restriction on the rolling of the left front wheel 3FL is released, and the rolling of the right rear wheel 3RR is restricted. Therefore, displacement of the vehicle body 2 in the longitudinal direction X is suppressed by the right rear wheel 3RR, and displacement of the vehicle body 2 in the left-right direction Y is suppressed by the left rear wheel 3RL and the right rear wheel 3RR.

[0056] Next, as shown in Figure 7(C), the steering devices 7RL and 7RR change the direction of the left rear wheel 3RL and the right rear wheel 3RR, causing the left rear wheel 3RL and the right rear wheel 3RR to also face the left-right direction Y. At this time, the restriction on the rolling of the right rear wheel 3RR is released, and the rolling of the left front wheel 3FL is restricted. Therefore, displacement of the vehicle body 2 in the longitudinal direction X is suppressed by the left front wheel 3FL and the right front wheel 3FR, and displacement of the vehicle body 2 in the left-right direction Y is suppressed by the left front wheel 3FL.

[0057] Then, as shown in Figure 7(D), after switching from normal driving mode to traverse mode, the rolling of the left front wheel 3FL and the right rear wheel 3RR is restricted until the automated guided vehicle 1 starts moving.

[0058] The automated guided vehicle 1 may have five or more wheels. The braking device may also restrict the rolling of three or more wheels, and the control device may control the steering device to restrict the rolling of two or more wheels included in the secondary steering wheels when changing the direction of the primary steering wheels, or to restrict the rolling of two or more wheels included in the primary steering wheels when changing the direction of the secondary steering wheels. [Explanation of Symbols]

[0059] 1. Automated Guided Vehicle (AGV) 2 car bodies 3F Front wheel 3R rear wheel (wheel) 3FL Left front wheel 3FR Right Front Wheel 3RL Left rear wheel 3RR Right Rear Wheel 7. Drive unit (braking device) 8. Steering gear 8 Control device X Anteroposterior direction Y left / right direction

Claims

1. An automated guided vehicle capable of switching between a normal driving mode that allows straight-line movement in the forward and backward directions and a traverse mode that allows straight-line movement in the left and right directions, It is equipped with multiple wheels spaced apart in the front-to-back and left-to-right directions, A braking device that limits the rolling of at least two of the aforementioned wheels, A steering device that changes the direction of multiple wheels, The system includes a control device for controlling the braking device and the steering device, The control device is Of the multiple wheels, one pair of wheels is designated as primary steering wheels, and the other pair of wheels is designated as secondary steering wheels. When switching between normal driving mode and traverse mode, the steering device is controlled so that the direction of the primary steering wheels is changed first, and then the direction of the secondary steering wheels is changed. Furthermore, the braking device is controlled to restrict the rolling of at least one of the wheels included in the secondary steering wheels when changing the direction of the primary steering wheels, and to restrict the rolling of at least one of the wheels included in the primary steering wheels when changing the direction of the secondary steering wheels. An automated guided vehicle characterized by the following features.

2. The aforementioned wheels consist of front and rear wheels spaced apart in the front-rear direction. The front wheels consist of a left front wheel and a right front wheel, spaced apart in the left-right direction, and the rear wheels consist of a left rear wheel and a right rear wheel, spaced apart in the left-right direction. In the pair of the left front wheel and the right rear wheel, and in the pair of the right front wheel and the left rear wheel, one is a primary steering wheel and the other is a secondary steering wheel. The automated guided vehicle according to feature 1.

3. The rolling motion of any one of the following pairs—the left front wheel and the left rear wheel, the right front wheel and the right rear wheel, the left front wheel and the right front wheel, or the left rear wheel and the right rear wheel—is restricted by the braking device. The automated guided vehicle according to feature 2.

4. The aforementioned wheels consist of front and rear wheels spaced apart in the front-rear direction. The front wheels consist of a left front wheel and a right front wheel, spaced apart in the left-right direction, and the rear wheels consist of a left rear wheel and a right rear wheel, spaced apart in the left-right direction. The primary steering wheels are one pair of the left front wheel and the left rear wheel, one pair of the right front wheel and the right rear wheel, one pair of the left front wheel and the right front wheel, or one pair of the left rear wheel and the right rear wheel. The automated guided vehicle according to feature 1.

5. The rolling motion of one of the following pairs of wheels—the left front wheel and the right rear wheel, and the right front wheel and the left rear wheel—is restricted by the braking device. The automated guided vehicle according to feature 4.

Images