Travel control system, travel control method, and program
The travel control system for a transport vehicle with an angle detection unit and speed adjustment based on relative angle changes addresses sudden load issues during direction changes, ensuring smoother operation and improved durability.
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- LEXXPLUSS INC
- Filing Date
- 2024-11-01
- Publication Date
- 2026-05-07
AI Technical Summary
Existing robot travel control systems apply sudden loads when changing direction due to frequent obstacle avoidance, which can strain the vehicle and affect its responsiveness to environmental changes.
A travel control system for a transport vehicle that tows an object, utilizing an angle detection unit to monitor the relative angle between the object and the vehicle, and adjusts speed by accelerating from a first speed to a second speed when the angle exceeds a specific threshold during direction changes.
This approach reduces sudden loads on the transport vehicle, allowing smoother direction changes and improved durability by gradually increasing speed based on the relative angle, thus enhancing the vehicle's responsiveness and reducing torque requirements.
Smart Images

Figure JP2024039130_07052026_PF_FP_ABST
Abstract
Description
Travel Control System, Travel Control Method, and Program
[0001] The present disclosure relates to a travel control system, a travel control method, and a program.
[0002] In the travel controller of the robot described in Patent Document 1, the direction and speed for moving the own vehicle to avoid an obstacle are calculated, and the process of actually moving the own vehicle according to the calculation result is repeatedly executed until it is determined that there is no possibility of collision. As a result, the robot moves along a trajectory deviating from the original path. Then, in the process of avoidance behavior, the front direction of the robot is controlled to maintain the direction (path vector) in the original path.
[0003] With this control, the robot can avoid obstacles with little change in the front direction of the own vehicle. Therefore, since the direction of the laser range finder does not change frequently, the load of the obstacle recognition process can be reduced, and the robot can quickly respond to changes in the external environment.
[0004] Japanese Patent Application Laid-Open No. 2009-288931
[0005] However, the robot described in Patent Document 1 can only avoid obstacles with little change in the front direction of the own vehicle, and depending on the situation, there is a possibility that a sudden load may be applied to the robot during avoidance behavior.
[0006] Therefore, the present disclosure has been made in view of the above problems, and an object thereof is to provide a travel control system, a travel control method, and a program that can suppress a sudden load from being applied to a carrier vehicle when the carrier vehicle changes its traveling direction and travels.
[0007] According to this disclosure, a travel control system for a transport vehicle that travels while towing an object to be transported, which is rotatably connected to the transport vehicle, is provided, comprising an angle detection unit for detecting the relative angle of the object to be transported with respect to the front-rear direction of the transport vehicle, starting the transport vehicle to travel in the front-rear direction from a state where the relative angle is an initial angle, traveling the transport vehicle at a first speed until the relative angle becomes a specific angle greater than the initial angle, and when the relative angle becomes greater than or equal to the specific angle, accelerating the transport vehicle from the first speed to a second speed greater than the first speed.
[0008] Furthermore, the present disclosure provides a method for controlling the travel of a transport vehicle that tows an object to be transported, which is rotatably connected to the transport vehicle, the method comprising: starting the transport vehicle to travel in a direction along the front-rear direction from a state in which the relative angle of the object to be transported with respect to the front-rear direction of the transport vehicle is an initial angle; driving the transport vehicle at a first speed until the relative angle becomes a specific angle greater than the initial angle; and, when the relative angle becomes greater than or equal to the specific angle, accelerating the transport vehicle from the first speed to a second speed greater than the first speed.
[0009] Furthermore, the present disclosure provides a program for causing a computer to execute a method for controlling the movement of a transport vehicle that travels while towing an object to be transported which is rotatably connected to the transport vehicle, the method of controlling the movement of the transport vehicle comprising: starting the transport vehicle to travel in a direction along the front-rear direction from a state in which the relative angle of the object to be transported with respect to the front-rear direction of the transport vehicle is an initial angle; traveling the transport vehicle at a first speed until the relative angle becomes a specific angle greater than the initial angle; and, when the relative angle becomes greater than or equal to the specific angle, accelerating the transport vehicle from the first speed to a second speed greater than the first speed.
[0010] According to this disclosure, it is possible to provide a travel control system, a travel control method, and a program that can suppress the sudden load on a transport vehicle when the transport vehicle changes direction of travel.
[0011] This is a plan view showing an example of a transport vehicle and a trolley according to one embodiment of the present disclosure. (a) to (c) are plan views showing the initial flow of an example of a travel control method according to the present embodiment. (a) to (c) are plan views showing the subsequent flow of an example of a travel control method according to the present embodiment. (a) to (c) are plan views showing the initial flow of another example of a travel control method according to the present embodiment. (a) and (b) are plan views showing the middle flow of another example of a travel control method according to the present embodiment. (a) and (b) are plan views showing the subsequent flow of another example of a travel control method according to the present embodiment. This is a perspective view showing an example of the hardware configuration of a transport vehicle according to the present embodiment. This is a bottom view showing an example of the hardware configuration of a transport vehicle according to the present embodiment. This is a perspective view showing an example of the hardware configuration when a transport vehicle and a trolley according to the present embodiment are connected. This is a plan view showing an example of the configuration of an operating area according to the present embodiment. This is a bottom view showing the positional relationship between the guideline and the transport vehicle when the line detection unit according to the present embodiment detects a two-dimensional code constituting the guideline. This is a bottom view showing the positional relationship between the guideline and the transport vehicle when the line detection unit according to the present embodiment detects a magnetic tape constituting the guideline. This is a diagram showing an example of the overall configuration of a transport system according to the present embodiment. This is a diagram showing the configuration of the central control device in this embodiment. This is a diagram showing the functional configuration of the transport vehicle according to this embodiment. This is a flowchart showing an example of a driving control method according to this embodiment. This is a flowchart showing an example of a driving control method according to a modified example of this embodiment.
[0012] Preferred embodiments of this disclosure will be described in detail below with reference to the attached drawings. In this specification and the drawings, components having substantially the same functional configuration are denoted by the same reference numerals, and redundant descriptions will be omitted.
[0013] A driving control system according to one embodiment of the present disclosure is used, for example, to control an automated guided vehicle (hereinafter also simply referred to as "transport vehicle") used to transport various manufactured parts, cargo, and other items in a manufacturing plant, logistics warehouse, etc. The driving control system is implemented, as an example, by the transport system 1000 (Figure 13) described later. This system is not limited to automated guided vehicles, but can also be applied to other manned and unmanned mobile vehicles.
[0014] For example, a transport vehicle has both an autonomous driving mode and a guided driving mode. Guided driving mode is a mode in which the transport vehicle moves along real or virtual guidelines. Autonomous driving mode is a mode in which the transport vehicle can move in areas where no guidelines are placed by estimating its own position.
[0015] Furthermore, the transport vehicle tows the object to be transported in both autonomous and guided driving modes. The object to be transported is rotatably connected to the transport vehicle. The object to be transported typically has at least one wheel. In this case, the object to be transported may be, for example, a trolley, a conveyor, or a robot (for example, a robot with a robotic arm).
[0016] First, the transport vehicle 10 and the trolley 2000 will be described with reference to Figure 1. Figure 1 is a plan view showing an example of a transport vehicle 10 and a trolley 2000 according to one embodiment of the present disclosure. As shown in Figure 1, the transport robot 20 comprises a transport vehicle 10 and a coupling device 21. The transport robot 20 transports the trolley 2000 by towing it.
[0017] The transport vehicle 10 includes a control unit 260, a recording unit 220, and an angle detection unit 237. The control unit 260 includes a processor such as a CPU (Central Processing Unit) and a GPU (Graphics Processing Unit). The control unit 260 is an example of a computer. The recording unit 220 stores data and computer programs. The recording unit 220 includes a main memory device such as a semiconductor memory, and an auxiliary memory device such as a semiconductor memory and a hard disk drive. The recording unit 220 may also include removable media such as an optical disc. The recording unit 220 may also include, for example, a non-temporary computer-readable storage medium.
[0018] The coupling device 21 connects the transport vehicle 10 and the trolley 2000 so that the trolley 2000 can rotate (oscillate) relative to the transport vehicle 10. The trolley 2000 corresponds to an example of the "object to be transported" in this disclosure.
[0019] As an example, the coupling device 21 includes a coupling body 22, a shaft member 23, and a coupling mechanism 24. One longitudinal end of the coupling body 22 is connected to the transport vehicle 10 by the shaft member 23. The shaft member 23 supports the coupling body 22 so that it can rotate (swing) around a pivot axis AX. The pivot axis AX extends, for example, along the vertical direction. In the example of Figure 1, the shaft member 23 is positioned on the center line CL1 of the width direction D10 of the transport vehicle 10 in a plan view. The width direction D10 of the transport vehicle 10 is approximately perpendicular to the front-rear direction D20 of the transport vehicle 10.
[0020] A coupling mechanism 24 is attached to the other longitudinal end of the connecting body 22. The coupling mechanism 24 connects to the bogie 2000 at the coupling point P3 of the bogie 2000. In this case, the coupling mechanism 24 connects to the bogie 2000 in such a way that the connecting body 22 cannot rotate (or swing) relative to the bogie 2000. As an example, the coupling mechanism 24 connects to the bogie 2000 at the coupling point P3 by gripping a predetermined part of the bogie 2000. In the example in Figure 1, in a plan view, the coupling point P3 is located on the center line CL2 of the width direction D11 of the bogie 2000. The width direction D11 of the bogie 2000 is approximately perpendicular to the front-rear direction D21 of the bogie 2000.
[0021] The coupling mechanism 24 is coupled to the trolley 2000 at coupling point P3 in a non-rotatable state, but it may be rotatable. If the coupling mechanism 24 is coupled to the trolley 2000 in a rotatable state, one end of the coupling body 22 in the longitudinal direction may be coupled to the transport vehicle 10 in a non-rotatable state.
[0022] As a result, the trolley 2000 is connected to the transport vehicle 10 by the coupling device 21 so that it can rotate around the pivot axis AX. In the example shown in Figure 1, the trolley 2000 is connected to the transport vehicle 10 at the rear by the coupling device 21.
[0023] Referring to Figure 1, the first specific location P1 and the rotation center P4 of the transport vehicle 10, and the second specific location P2 of the trolley 2000 will be explained. The first specific location P1 indicates the position of the transport vehicle 10. In other words, the position of the transport vehicle 10 is indicated by the position of the first specific location P1. The position of the transport vehicle 10 indicated by the first specific location P1 may be described as "self-position" or "vehicle position".
[0024] Here, the transport vehicle 10 further includes a line detection unit 16. The line detection unit 16 detects the guideline. Details of the line detection unit 16 will be described later.
[0025] The first specific location P1 is, for example, the center of the line detection unit 16. The rotation center P4 is the center of rotation when the transport vehicle 10 rotates. Rotation indicates that the transport vehicle 10 rotates around the rotation center P4 while virtually no movement in the forward, backward, left, or right directions. In the example in Figure 1, the first specific location P1 and the rotation center P4 are located on the center line CL1. The first specific location P1 and the rotation center P4 may be in different positions or they may coincide.
[0026] The second specific point P2 on the trolley 2000 indicates the position of the trolley 2000. In other words, the position of the trolley 2000 is indicated by the position of the second specific point P2. In the example in Figure 1, the second specific point P2 is located on the centerline CL2 of the trolley 2000. Furthermore, the orientation of the trolley 2000 is indicated by the relative angle α of the centerline CL2 of the trolley 2000 with respect to the centerline CL1 of the transport vehicle 10. In other words, the orientation of the trolley 2000 is indicated by the relative angle α of the trolley 2000 with respect to the longitudinal direction D20 of the transport vehicle 10. The relative angle α is defined with respect to the front in the longitudinal direction D20 of the transport vehicle 10. For example, the relative angle α is expressed as the range from zero to 180 degrees clockwise around the rotation axis AX, with the front of the transport vehicle 10 as the reference point in a plan view, and from zero to 180 degrees counterclockwise around the rotation axis AX, with the front of the transport vehicle 10 as the reference point in a plan view. Note that positive and negative signs may be assigned to the clockwise and counterclockwise directions. In this case, for example, in the travel control shown in Figures 2 to 6, 16 and 17, the relative angle α represents the absolute value of the relative angle α.
[0027] Furthermore, guideline 111 is placed on the floor surface. In the example in Figure 1, guideline 111 is a real guideline. Note that guideline 111 may also be a virtual guideline. For example, guideline 111 extends in a straight line.
[0028] The transport vehicle 10 can move along real or virtual guidelines 111 while towing the trolley 2000. Real guidelines 111 are signs installed on the floor, wall, or ceiling, or signs rising from these surfaces, to guide the transport vehicle 10, and may be in a continuous linear pattern or signs arranged intermittently in a linear pattern. The guidelines 111 may be made of magnetic tape, for example. Alternatively, the guidelines 111 may be made of multiple 2D codes arranged in a continuous or intermittent pattern. Virtual guidelines 111 may be virtual 2D or 3D guidelines set on 2D or 3D map data corresponding to real space. In any case, the guidelines 111 are set and arranged so that the transport vehicle 10 can be guided to a predetermined location (destination, waypoint) by being referred to when the transport vehicle 10 is operating.
[0029] The angle detection unit 237 detects the relative angle α of the trolley 2000 with respect to the front-rear direction D20 of the transport vehicle 10. In the example shown in Figure 1, the angle detection unit 237 is positioned at the connection point between the transport vehicle 10 and the connecting body 22. For example, the angle detection unit 237 includes a rotary encoder provided on the shaft member 23 and measures the relative angle α as the displacement angle from a predetermined state. Alternatively, for example, the angle detection unit 237 includes an angle sensor such as a rotary potentiometer to detect the relative angle α. Alternatively, for example, the angle detection unit 237 includes a distance measuring sensor and estimates the relative angle α with respect to the transport vehicle 10 by measuring the distance from the transport vehicle 10 to specific points on the left and right sides of the trolley 2000. In addition, the angle detection unit 237 may measure the relative angle α by means of a resolver, for example.
[0030] The angle detection unit 237 outputs information indicating the relative angle α to the control unit 260, for example, at regular time intervals, when specific conditions are met, or in response to a request from the control unit 260. When specific conditions are met, for example, when the transport vehicle 10 has traveled a predetermined distance (each time it travels a predetermined distance), when the direction of travel of the transport vehicle 10 has changed by a predetermined angle, or when the transport vehicle 10 has moved from a stationary state (each time it has moved from a stationary state).
[0031] Furthermore, Figure 1 shows the state in which the transport vehicle 10 enters the guideline 111 at an angle β. Angle β represents the angle of the transport vehicle 10 in the front-rear direction D20 (centerline CL1) relative to the guideline 111. Angle β is, for example, approximately 90 degrees, an acute angle, or an obtuse angle. Note that, for example, if the line detection unit 16 uses an image recognition method in which a two-dimensional code or barcode is read by a camera, the control unit 260 can generate position information based on the detected code information in addition to the detection signal of the guideline 111, and further analyze the image information of the code to generate angle β, which is the relative angle information between the guideline 111 and the transport vehicle 10.
[0032] In the following explanation of Figures 2 to 6, as an example, the axle member 23 of the transport vehicle 10 is positioned at the center of rotation P4, and the second specific point P2 of the trolley 2000 is set as the center of gravity of the trolley 2000.
[0033] Next, an example of a method for controlling the movement of the transport vehicle 10 will be described with reference to Figures 2 and 3. For example, a method for controlling movement in autonomous driving mode will be shown. Figures 2 and 3 are plan views showing an example of the flow of the movement control method. As shown in Figures 2 and 3, the method for controlling the movement of the transport vehicle 10 includes steps S1 to S6.
[0034] First, as shown in Figure 2(a), in step S1, the control unit 260 moves the transport vehicle 10 in direction D1. In the example in Figure 2(a), the relative angle α (Figure 1) of the trolley 2000 with respect to the transport vehicle 10 is approximately 180 degrees.
[0035] Next, as shown in Figure 2(b), in step S2, the control unit 260 stops the transport vehicle 10.
[0036] Next, as shown in Figure 2(c), in step S3, the control unit 260 rotates the transport vehicle 10 so that the relative angle α becomes the initial angle θa from the stopped state of the transport vehicle 10. As a result, the transport vehicle 10 faces the target direction D2. In other words, the control unit 260 rotates the transport vehicle 10 so that it faces the target direction D2 from the stopped state of the transport vehicle 10. The initial angle θa is the angle at which the transport vehicle 10 starts moving after it has stopped. Direction D1 is the direction of travel of the transport vehicle 10 before it moves in the target direction D2. Therefore, before it moves in the target direction D2, the center line CL2 of the trolley 2000 is approximately parallel to direction D1. Also, in this example, since the direction of travel of the transport vehicle 10 is changed by approximately 90 degrees from direction D1 (Figure 2(a)), the target direction D2 is approximately perpendicular to direction D1.
[0037] The initial angle θa is greater than zero degrees. The initial angle θa is not particularly limited, but for example, it is an angle between approximately 80 degrees and approximately 100 degrees. In the example in Figure 2(c), the initial angle θa is approximately 90 degrees.
[0038] In the example shown in Figure 1, the rotation center P4 and the shaft member 23 are separated, but as shown in Figure 2(c), it is preferable that the positions of the rotation center P4 and the shaft member 23 coincide. This is because even when the transport vehicle 10 rotates, the movement of the trolley 2000 is suppressed, allowing the transport vehicle 10 to rotate smoothly.
[0039] Next, as shown in Figure 3(a), in step S4, the control unit 260 starts the transport vehicle 10 traveling toward the target direction D2 from a stopped state (Figure 2(c)). In this case, the target direction D2 coincides with the direction along the front-rear direction D20 of the transport vehicle 10. In other words, the control unit 260 starts the transport vehicle 10 traveling toward the front-rear direction D20 of the transport vehicle 10 from a stopped state (from a state where the relative angle α is the initial angle θa).
[0040] Next, as shown in Figure 3(b), in step S5, the control unit 260 accelerates the transport vehicle 10 from a stopped state to a first speed V1. The control unit 260 then maintains the speed of the transport vehicle 10 at the first speed V1. As the transport vehicle 10 moves, the relative angle α gradually increases. The control unit 260 then drives the transport vehicle 10 at the first speed V1 until the relative angle α becomes a specific angle θb that is greater than the initial angle θa.
[0041] The control unit 260 acquires information indicating the speed of the transport vehicle 10 from a speed sensor (for example, the distance traveled detection unit 233 in Figure 15).
[0042] Next, as shown in Figure 3(c), in step S6, when the relative angle α becomes greater than or equal to a specific angle θb, the control unit 260 accelerates the transport vehicle 10 from the first speed V1 to the second speed V2. The second speed V2 is greater than the first speed V1. The control unit 260 then maintains the speed of the transport vehicle at the second speed V2.
[0043] As described above with reference to Figures 2 and 3, according to this embodiment, the transport vehicle 10 travels at a first speed V1 which is smaller than the second speed V2 until the relative angle α becomes a specific angle θb (step S5). Therefore, the relative angle α gradually increases as the vehicle travels at a small first speed V1. When the relative angle α becomes greater than or equal to the specific angle θb, the transport vehicle 10 accelerates to the second speed V2 (step S6). In this way, the target speed of the transport vehicle 10 is increased in stages according to the magnitude of the relative angle α of the trolley 2000 with respect to the longitudinal direction D20 of the transport vehicle 10. In other words, in the initial stages of travel when the relative angle α is relatively small, the transport vehicle 10 travels at a small first speed V1, and when the relative angle α becomes relatively large, the transport vehicle 10 is accelerated to a large second speed V2.
[0044] Therefore, when the transport vehicle 10 changes direction and travels, compared to the case where the transport vehicle 10 is immediately accelerated to the second speed V2 after rotation, the sudden load on the transport vehicle 10 can be suppressed. As a result, the transport vehicle 10 is not required to generate a sudden torque when changing direction and can start traveling smoothly. In addition, the durability of the transport vehicle 10 and the coupling device 21 can be improved.
[0045] In particular, the closer the initial angle θa is to 90 degrees, the greater the load on the carrier vehicle 10 may be when accelerating the carrier vehicle 10 in the direction along the longitudinal direction D20. Therefore, when the carrier vehicle 10 changes its traveling direction by approximately 90 degrees, the load on the carrier vehicle 10 may be the greatest when accelerating the carrier vehicle 10.
[0046] That is, in step S3, in order to change the traveling direction by approximately 90 degrees, the control unit 260 may rotate the carrier vehicle 10 from a stopped state so that the relative angle α becomes approximately 90 degrees (= initial angle θa). In this case, if the speed of the carrier vehicle 10 is immediately accelerated to the second speed V2, the load on the carrier vehicle 10 may become particularly large. Therefore, in the present embodiment, by gradually increasing the target speed of the carrier vehicle 10 according to the magnitude of the relative angle α (steps S5, S6), even when changing the traveling direction by approximately 90 degrees, the abrupt load on the carrier vehicle 10 can be more effectively suppressed. As a result, the carrier vehicle 10 is not required to generate an abrupt torque and can smoothly start running.
[0047] Further, in the present embodiment, the control unit 260 directs the carrier vehicle 10 toward the target direction D2 by rotating the carrier vehicle 10 in a stopped state (step S3). Therefore, compared with the case of changing the traveling direction without stopping the carrier vehicle 10, the control for directing the carrier vehicle 10 toward the target direction D2 is easy, and the time for directing the carrier vehicle 10 toward the target direction D2 can be shortened.
[0048] Furthermore, in the present embodiment, the specific angle θb when changing the target speed of the carrier vehicle 10 to the second speed V2 is preferably an angle of approximately 110 degrees or more and approximately 120 degrees or less. According to this preferred example, experimentally and / or empirically, the speed of the carrier vehicle 10 can be accelerated from the first speed V1 to the second speed V2 more smoothly.
[0049] Next, with reference to Figures 4 to 6, other examples of the travel control method for the transport vehicle 10 will be described. For example, a travel control method in guided travel mode will be shown. Figures 4 to 6 are plan views showing other examples of the flow of the travel control method. As shown in Figures 4 to 6, the travel control method for the transport vehicle 10 includes steps S11 to S17.
[0050] First, as shown in Figure 4(a), in step S11, the control unit 260 causes the transport vehicle 10 to travel in the direction D1 indicating the position of the guideline 111 (not shown in Figure 4(a)).
[0051] Next, as shown in Figure 4(b), in step S12, the control unit 260 stops the transport vehicle 10 so that the first specific location P1 is positioned on the guideline 111. In other words, the control unit 260 stops the transport vehicle 10 at the position where the line detection unit 16 detects the guideline 111.
[0052] Next, as shown in Figure 4(c), in step S13, the control unit 260 moves the transport vehicle 10 forward (straight) along the longitudinal direction D20 so that the rotation center P4 of the transport vehicle 10 is positioned on the guideline 111. Specifically, the control unit 260 moves the transport vehicle 10 forward along the longitudinal direction D20 by a distance L4 and then stops it. The distance L4 is the distance between the first specific point P1 (line detection unit 16) and the rotation center P4. Information indicating the distance L4 is stored in advance in the recording unit 220 (Figure 1).
[0053] Next, as shown in Figure 5(a), in step S14, the control unit 260 rotates the transport vehicle 10 so that the relative angle α becomes the initial angle θa, starting from the state where the rotation center P4 is located on the guideline 111. As a result, the transport vehicle 10 faces the target direction D2.
[0054] In this case, the target direction D2 of the transport vehicle 10 coincides with the longitudinal direction D20 of the transport vehicle 10 and the direction in which the guideline 111 extends. Therefore, the initial angle θa represents the angle of the longitudinal direction D21 of the trolley 2000 relative to the guideline 111. Thus, in step S14, the control unit 260 substantially rotates the transport vehicle 10 so that the first specific location P1 (Figure 4(c)), which is located outside the guideline 111, is positioned on the guideline 111. In other words, the control unit 260 rotates the transport vehicle 10 until the line detection unit 16 detects the guideline 111.
[0055] The initial angle θa is the same as the subtraction result obtained by subtracting the angle β (Figure 1) when the transport vehicle 10 enters the guideline 111 from 180 degrees.
[0056] Here, the initial angle θa is the same as the initial angle θa explained with reference to Figure 2(c). For example, if the transport vehicle 10 enters the guideline 111 at an angle β (Figure 1) of approximately 90 degrees, then in Figure 5(a), the initial angle θa is approximately 90 degrees.
[0057] Next, as shown in Figure 5(b), in step S15, the control unit 260 starts the transport vehicle 10 moving along the guideline 111 toward the target direction D2, starting from a stopped state (Figure 5(a)). In other words, the control unit 260 starts the transport vehicle 10 moving along the guideline 111 in the direction along the front-rear direction D20 of the transport vehicle 10, starting from a stopped state.
[0058] Next, as shown in Figure 6(a), in step S16, the control unit 260 accelerates the transport vehicle 10 from a stopped state to a first speed V1. Then, the control unit 260 maintains the speed of the transport vehicle 10 at the first speed V1. Otherwise, step S16 is the same as step S5 in Figure 3(b).
[0059] Next, as shown in Figure 6(b), in step S17, if the relative angle α becomes greater than or equal to a specific angle θb, the control unit 260 accelerates the transport vehicle 10 from the first speed V1 to the second speed V2. The control unit 260 then maintains the speed of the transport vehicle at the second speed V2. Otherwise, step S17 is the same as step S6 in Figure 3(c). Furthermore, it is preferable that the specific angle θb is an angle of approximately 110 degrees or more and approximately 120 degrees or less.
[0060] As described above with reference to Figures 4 to 6, according to the driving control method of this embodiment, the target speed of the transport vehicle 10 is increased in steps according to the magnitude of the relative angle α of the trolley 2000 with respect to the longitudinal direction D20 of the transport vehicle 10 (steps S16, S17). Therefore, even in the guided driving mode, as in the case of the autonomous driving mode described with reference to Figures 2 and 3, it is possible to suppress the sudden load on the transport vehicle 10 when the transport vehicle 10 changes direction of travel. As a result, the transport vehicle 10 is not required to generate a sudden torque when changing direction of travel, and can start driving smoothly. In addition, the durability of the transport vehicle 10 and the coupling device 21 can be improved.
[0061] <Transport Vehicle Configuration> Figure 7 is a perspective view showing an example of the hardware configuration of the transport vehicle 10 according to this embodiment. Although the transport vehicle 10 in this example is an unmanned transport vehicle, it can also be applied to various vehicles that can carry people. The arrow 15 in Figure 7 indicates the direction of travel (forward) of the transport vehicle 10. The direction of travel is basically forward of the transport vehicle 10, but it can also be backward depending on the situation. As shown in Figure 7, the transport vehicle 10 is equipped with an object position detection unit 12 for detecting objects around the transport vehicle 10, drive wheels 13, and non-drive wheels 14. The transport vehicle 10 is also equipped with a shaft member 23 of a coupling device 21 (Figure 1) for connecting a trolley 2000.
[0062] The object position detection unit 12 corresponds to an example of the "object detection unit" in this disclosure.
[0063] The object position detection unit 12 detects objects without contact. Specifically, the object position detection unit 12 can also detect the relative distance and angle from the transport vehicle 10 to an object (including a trolley 2000, a person, etc.). The object position detection unit 12 can be a laser distance sensor (such as LiDAR (Light detection and ranging)) that measures the distance and direction to an object by irradiating a laser beam and measuring the time it takes for the beam to hit the object and bounce back, a millimeter-wave radar that detects the distance to an object based on a millimeter-wave transmission signal and a received signal that is reflected back from the object, or a camera-type distance sensor that measures the distance to an object by photographing the object with a camera and analyzing the captured image. In this embodiment, an example is shown in which the object position detection unit 12 is placed on the upper surface of the transport vehicle 10 in the direction of travel, but it may be placed on the front side in the direction of travel instead. It may also be placed not only on the front but also on the rear side or both left and right sides in the direction of travel.
[0064] The object position detection unit 12 can detect the position and orientation (relative position and angle to the transport vehicle 10) of the trolley 2000 connected to the transport vehicle 10. The object position detection unit 12 may be configured to detect objects in a 360-degree radius around the transport vehicle 10, but it is configured to detect objects at least in the direction of travel 15 of the transport vehicle 10. The direction of travel 15 may be in front of or behind the transport vehicle 10.
[0065] Figure 8 is a bottom view showing an example of the hardware configuration of the transport vehicle 10 according to this embodiment. Figure 8 shows the bottom surface of the transport vehicle 10. Drive wheels 13 are provided on the bottom surface of the transport vehicle 10 at positions on both the left and right sides with respect to the direction of travel 15 of the transport vehicle 10, and non-drive wheels 14 are provided in front of and behind each drive wheel 13. The drive wheels 13 are wheels that are driven by being connected to the rotating shaft of a motor, and the right drive wheel 13 and the left drive wheel 13 are controlled individually. The control unit 260 can control the speed of the transport vehicle 10 by controlling the rotation speed of the drive wheels 13. Furthermore, by individually controlling the rotation speed and rotation direction of each drive wheel 13, the control unit 260 can make the transport vehicle 10 curve, rotate the transport vehicle 10 in place to change direction, stop, or move in reverse.
[0066] For example, the control unit 260 can make the transport vehicle 10 rotate around the center of rotation P4 by controlling the two drive wheels 13 to have the same rotational speed and different rotational directions (for example, step S3 in Figure 2(c), step S14 in Figure 5(a)). The midpoint of the pair of drive wheels 13 is the center of rotation P4. For example, the control unit 260 can make the transport vehicle 10 rotate by controlling the two drive wheels 13 to have different rotational speeds and the same rotational direction.
[0067] The non-driven wheels 14 are wheels that are not driven and rotate passively as the transport vehicle 10 moves due to the drive wheels 13. The non-driven wheels 14 have, for example, forks that fix the wheel to the axle, and the forks are composed of swivel casters that are rotatably connected to the bottom surface member of the transport vehicle 10. Therefore, the direction of rotation of the non-driven wheels 14 changes passively according to the direction of travel and rotational movement of the transport vehicle 10. In other words, the non-driven wheels 14 are swivel wheels that can rotate freely 360 degrees while in contact with the floor surface.
[0068] Figure 8 illustrates a hardware configuration of a transport vehicle 10 having two drive wheels 13 and four non-drive wheels 14 at the four corners. However, this disclosure is not limited to this hardware configuration. It is also possible to adopt a configuration with a total of four wheels, consisting of two drive wheels 13 and two non-drive wheels 14. Furthermore, it is possible to adopt a configuration in which the front wheels are steerable in this four-wheel configuration.
[0069] A line detection unit 16 for detecting the guideline 111 is provided on the bottom surface of the transport vehicle 10. Preferably, the line detection unit 16 is provided in front of the drive wheels 13 in the direction of travel of the transport vehicle 10. This makes it easier to follow the guideline 111 when traveling along a curved section of the guideline 111, and also allows for quick execution of stopping or other processing by receiving information from the guideline 111 as soon as the transport vehicle 10 and the towing trolley 2000 move. The line detection unit 16 uses a sensor according to the type of guidance method. If an electromagnetic guidance method is used, a pickup coil is used; if a magnetic guidance method is used, a magnetic sensor is used; and if an image recognition method is used, a camera is used as the sensor of the line detection unit 16. The guideline 111 is not limited to the floor surface, but may also be provided on the side walls or ceiling of a building, and the sensors (including cameras) of the transport vehicle 10 can be installed in a position where the guideline 111 can be recognized (such as the bottom, side, or top surface of the transport vehicle 10). Furthermore, the guideline 111 may be a virtual track provided on two-dimensional or three-dimensional map data. The control unit 260 of the transport vehicle 10 may control the movement of the transport vehicle 10 in accordance with the virtual guideline 111 based on map information and track information (movement path information) stored in advance in the recording unit 220, and current self-position information estimated based on information from cameras, sensors, etc.
[0070] Information regarding the position of the shaft member 23 is stored in advance in the recording unit 220. The position of the line detection unit 16 may be set using three-dimensional coordinates. As shown in Figure 8, the center point (midpoint) between the left and right drive wheels 13 is the rotation center P4. In this example, the rotation center P4 coincides with the center of the transport vehicle 10, but it may be offset. Information regarding the relative positional relationship between the rotation center P4, the center of the transport vehicle 10, and the shaft member 23, such as the distance L2 from the rotation center P4 to the shaft member 23 and the distance L3 from the center of the transport vehicle 10 to the shaft member 23, is also stored in advance in the recording unit 220. In addition, the distance L4 between the line detection unit 16 (first specific location P1) and the rotation center P4, and the distance L1 between the line detection unit 16 (first specific location P1) and the shaft member 23 are also stored in advance in the recording unit 220.
[0071] Figure 9 shows an example of the hardware configuration when the transport vehicle 10 and the trolley 2000 are coupled according to this embodiment. The trolley 2000 is connected to the transport vehicle 10 by a coupling device 21 so as to be able to rotate (oscillate) with the axle member 23 as the pivot point.
[0072] The trolley 2000 has at least one wheel 2001. In the example shown in Figure 9, the trolley 2000 has four wheels 2001. All wheels 2001 are, for example, swivel wheels that can rotate freely 360 degrees while in contact with the floor surface. Note that some of the wheels 2001 may include fixed wheels.
[0073] Figure 10 shows an example of the configuration of the operating area 130 according to this embodiment. As shown in Figure 10, guidelines 131 are laid within the operating area 130, and when a transport vehicle 10 traveling in autonomous driving mode detects the guidelines 131 at a pre-set driving mode switching position 132, the driving control mode is switched from autonomous driving mode to guided driving mode. Conversely, when a transport vehicle 10 traveling in guided driving mode on the guidelines 131 enters a pre-set driving mode switching position 132, the driving control mode is switched from guided driving mode to autonomous driving mode. In order to guide the transport vehicle 10 to a position close to shelves or belt conveyors where goods are stored or to the work positions of workers, the track composed of the guidelines 131 is laid at positions close to the shelves and work positions via multiple branching points.
[0074] When a transport vehicle 10 is traveling in autonomous driving mode in an autonomous driving area where guideline 131 is not laid, it changes its driving mode to guided driving mode, which follows guideline 131, provided that it enters a driving mode switching position 132 and detects guideline 131. On the other hand, when a transport vehicle 10 traveling in guided driving mode on guideline 131 enters a driving mode switching position 132, the driving control mode switches from guided driving mode to autonomous driving mode, and the transport vehicle 10 leaves guideline 131 and starts autonomous driving.
[0075] As shown in Figure 10, the guideline 131 can be one of various commonly used induction methods, as described later. Specifically, for example, an electromagnetic induction method can be applied, in which a magnetic field generated by passing a weak alternating current through a metal wire installed as the guideline 131 is detected by a pickup coil on the transport vehicle side; a magnetic induction method can be applied, in which a magnetic tape laid on the floor as the guideline 131 is read by a magnetic sensor on the transport vehicle side; or an image recognition method can be applied, in which an image of a code (barcode, two-dimensional code, etc.) laid on the floor as an induction line is captured by a camera on the transport vehicle 10 and image processing is performed.
[0076] Figure 11 shows the positional relationship between the guideline 111 and the transport vehicle 10 when the line detection unit 16 detects the two-dimensional code 1001 that constitutes the guideline 111. The guideline 111 consists of multiple two-dimensional codes 1001, each printed with code information on a two-dimensional plane as shown in the two-dimensional code 1001, and these codes are printed in a line aligned in the direction in which the guideline 111 is laid. When the line detection unit 16 detects a two-dimensional code 1001, it obtains the positional information of the two-dimensional code 1001 based on the code information obtained from the two-dimensional code 1001.
[0077] Figure 12 shows the positional relationship between the guideline 111 and the transport vehicle 10 when the line detection unit 16 detects the magnetic tape constituting the guideline 111. The line detection unit 16 shown in Figure 12 is configured to have multiple magnetic sensors 17 for detecting the magnetic tape, arranged laterally in the direction of travel of the transport vehicle 10. Each of the multiple magnetic sensors 17 provided in the line detection unit 16 outputs a detection signal indicating whether or not it has detected the magnetic tape. In the case shown in Figure 12, the three magnetic sensors 17A located in the center of the line detection unit 16 have detected the magnetic tape, while the two magnetic sensors 17B on each side of the line detection unit 16 have not detected the magnetic tape. This makes it possible to detect where the guideline is located (rightward, leftward, center, etc.) within the range of the line detection unit 16 (the entire area including the multiple magnetic sensors).
[0078] <Configuration of the Transport System> Next, the configuration of the transport system 1000 of this embodiment will be described. The transport system 1000 corresponds to an example of the "travel control system" of this disclosure. In other words, the transport system 1000 is a travel control system for a transport vehicle 10 to which a trolley 2000 is rotatably (swingably) connected, and which can move along a real or virtual guideline 111 while towing the trolley 2000.
[0079] Figure 13 shows an example of an overall configuration diagram of the transport system 1000 according to this embodiment. The transport system 1000 includes a plurality of transport vehicles 10, a trolley 2000 which is the object to be transported, a control unit 3000 which can display the status of the transport vehicles 10 or input commands to the transport vehicles 10, a central control unit 4000 which manages information necessary for the operation of the transport vehicles 10, an input / output device 5000 which displays information from the central control unit 4000 and inputs information to the central control unit 4000, and a communication network 6000 which connects the plurality of transport vehicles 10, the control unit 3000 and the central control unit 4000 so that they can communicate with each other. Various devices such as the control unit 3000, the central control unit 4000 and the input / output device 5000 may be separate devices, or some or all of them may be formed as an integrated device.
[0080] Furthermore, the transport system 1000 can also be connected to an external system 7000 via a communication network 6000. When the transport system 1000 is introduced into a manufacturing plant to transport parts necessary for manufacturing from a storage area to the production line, the transport system 1000 acts as an external system 7000 and performs system-to-system coordination with the manufacturing management system. In this case, by obtaining information on the operational progress of manufacturing work from the manufacturing management system, the transport volume and transport route of the transport vehicle 10 can be dynamically adjusted according to the operational progress of the manufacturing work.
[0081] As another example, if the transport system 1000 is introduced into a logistics warehouse to transport incoming goods from the entrance to the storage area when goods are brought into the warehouse by truck, etc., and transport outgoing goods from the storage area to the exit when goods are shipped from the warehouse, the transport system 1000 will function as an external system 7000 and perform system-to-system communication with the logistics management system. In this case, by obtaining information on incoming goods and outgoing goods from the logistics management system, the transport volume and transport route of the transport vehicle 10 can be changed.
[0082] In facilities where the transport system 1000 is introduced, multiple transport vehicles 10 are generally in operation, and each transport vehicle 10 is connected to other transport vehicles 10 and other components via a communication network 6000 so as to be able to communicate with them. For example, a transport vehicle 10 transmits various detection information and other control information detected by its own detection unit to the control unit 3000, the central control unit 4000, and other transport vehicles 10. The transport vehicle 10 is also electrically connected to the trolley 2000 or connected to it via short-range communication means so as to be able to receive information regarding the connection status and identification information of the trolley 2000 from the trolley 2000.
[0083] The control unit 3000 has the function of displaying status information for each transport vehicle 10 and the function of inputting commands to a designated transport vehicle 10. For example, the status information of the transport vehicles 10 displayed on the control unit 3000 includes the identification information of each transport vehicle 10, its position (coordinates, position on the map), speed, direction, travel history, information on the charge level of the battery mounted on the transport vehicle 10 that powers the transport vehicle 10, and the identification information of the trolley 2000 that the transport vehicle 10 transports. Commands to be input to the transport vehicle 10 include, for example, command information regarding the destination (target position) of the transport vehicle 10, commands for connecting to and disconnecting from the trolley 2000, a command to start the transport vehicle 10 from traveling, a command to stop the transport vehicle 10, and a command to return to the charging station.
[0084] Figure 14 shows a configuration diagram of the central control device 4000 in this embodiment. The central control device 4000 includes a status information recording unit 4010 that records status information of multiple transport vehicles 10 operating in the facility area, an operation scenario management unit 4020 that manages operation scenarios of multiple transport vehicles 10, a map management unit 4030 that generates and updates a work area map based on detection information of the transport vehicles 10, including detection information of guidelines 111 acquired by the line detection unit 16 of the transport vehicles 10, an abnormality determination unit 4040 that determines abnormalities in the guidelines 111 and the transport vehicles 10 based on the detection information of the transport vehicles 10, and a communication unit 4050 that communicates with an external input / output device 5000 and a communication network 6000.
[0085] The status information of the transport vehicle 10 recorded by the status information recording unit 4010 includes, for example, obstacle detection locations, guideline detection locations, and historical information of the transport vehicle 10's travel position, as well as battery charge level information, identification information of the trolley 2000 connected to the multiple transport vehicles 10, the operating mode of the multiple transport vehicles 10 (guided driving mode or autonomous driving mode), various detection information detected by the detection unit 230 of the transport vehicle 10, and map information of the work area. The operation scenario managed by the operation scenario management unit 4020 is information that defines a series of operations that the transport vehicle 10 should perform. The operation scenario includes, for example, information on the destination of each of the multiple transport vehicles 10, multiple operations to be performed to reach the destination, the order of operations for the multiple operations, and the conditions for switching between operations.
[0086] The map management unit 4030 generates a map containing location information of obstacles and guidelines 111 within the work area based on the obstacle detection locations, guideline detection locations, and historical information of the transport vehicle 10's travel position detected by the transport vehicle 10. Furthermore, the map management unit 4030 updates the information of the guidelines 111 and work area registered in the map based on the guideline detection location information accumulated by one or more transport vehicles 10.
[0087] The abnormality determination unit 4040 determines abnormalities in the guideline 111 and the transport vehicle 10 based on the location information of the guideline 111 registered in the map information and the detection information of the transport vehicle 10, which includes the detection location information of the guideline 111 detected by the transport vehicle 10.
[0088] The input / output device 5000 displays information recorded in the status information recording unit 4010 of the central control device 4000, map information (including map update information), and the judgment results from the abnormality judgment unit 4040. It also allows the addition or updating of operation scenarios by inputting operation scenarios managed by the operation scenario management unit 4020. The information input to the input / output device 5000 includes, for example, that the destination of any transport vehicle 10 is a work area in the guided driving area, the operation details for entering the guided driving area and reaching the work area, and operation switching conditions.
[0089] <Functions of the Transport Vehicle> The functions of the transport vehicle 10 will be explained using Figure 15. Figure 15 is a diagram showing the functional configuration of the transport vehicle 10 according to this embodiment. The transport vehicle 10 includes a communication unit 210 that communicates with an external trolley 2000 and a communication network 6000, a recording unit 220 (including a storage unit), a detection unit 230 equipped with various sensors which will be described later, a wheel drive unit 280 that drives the drive wheels 13, an input unit 240, a display unit 250, and a control unit 260. The control unit 260 controls the operation of the transport vehicle 10 by controlling the wheel drive unit 280 of the transport vehicle 10.
[0090] The recording unit 220 has the function of recording information received from the outside by the communication unit 210, detection information detected by the detection unit 230, and information generated and output by the control unit 260. The recording unit 220 stores location information of the first specific location P1 of the transport vehicle 10, etc. The recording unit 220 can store information such as the destination location, travel route, and travel history of the transport vehicle 10. The recording unit 220 can store speed information corresponding to the distance to the destination location, calculation formula (program) information for calculating said speed information, etc.
[0091] The detection unit 230 includes an object position detection unit 12, a line detection unit 16, a travel distance detection unit 233, a collision detection unit 234, an attitude detection unit 235, a charge level detection unit 236, and an angle detection unit 237. As described above, the object position detection unit 12 is composed of a laser distance sensor (such as LiDAR (Light detection and ranging)) that measures the distance and direction to an object by irradiating a laser beam and measuring the time it takes for the beam to hit the object and bounce back, a millimeter-wave radar that detects the distance to an object based on a millimeter-wave transmission signal and a received signal that is reflected back from the object, or a camera-type distance sensor that measures the distance to an object by photographing the object with a camera and analyzing the captured image. The control unit 260 can estimate the current position and current speed of the transport vehicle 10 based on the information from the detection unit 230. The detection unit 230 may also include a position sensor including GNSS, etc., for detecting the current position of the transport vehicle 10, and a speed sensor for detecting the speed of the transport vehicle 10.
[0092] As described above, the line detection unit 16 uses a sensor corresponding to the type of induction method. When using the electromagnetic induction method, a pickup coil is used as the sensor for the line detection unit 16; when using the magnetic induction method, a magnetic sensor is used; and when using the image recognition method, a camera is used. The line detection unit 16 detects the guideline 111 and outputs a detection signal when it is positioned directly above the guideline 111. Furthermore, in the case of the image recognition method, in which the camera reads the guideline 111 using a two-dimensional code or barcode, the control unit 260 generates position information based on the detected code information in addition to the detection signal of the guideline 111, and can generate relative angle information (angle β in Figure 1) between the guideline 111 and the transport vehicle 10 by further analyzing the image information of the code.
[0093] The distance detection unit 233 can detect the rotational speed of the non-driven wheels 14 or the driven wheels 13, and measure the distance traveled and the speed of the transport vehicle 10 based on the detected rotational speed information and the diameter (or circumference) information of the non-driven wheels 14 or the driven wheels 13. In this case, the distance detection unit 233 functions as a speed sensor. Alternatively, it is also possible to apply a method that uses a millimeter-wave sensor to detect the speed of the transport vehicle 10 by irradiating millimeter waves in any horizontal direction (even a wall or floor) and detecting the reflected wave, and then estimate the distance traveled by integrating the said speed. Furthermore, any method other than those described above for measuring distance traveled or obtaining speed traveled can be applied.
[0094] The collision detection unit 234 has the function of detecting when the transport vehicle 10 collides with an object or a person. Specifically, it can detect acceleration using a gyro sensor or the like, and determine that a collision has occurred when a sudden change in acceleration is detected. As an alternative, it is also possible to apply a means in which a physical switch is installed along with the bumper in the forward direction of travel of the transport vehicle 10, and a collision is determined when the physical switch is pressed. In addition, collision detection methods other than those described above can be applied. When the collision detection unit 234 detects a collision, it stops the transport vehicle 10, records at least one of the collision occurrence information and the collision occurrence location information in the recording unit 220, and notifies the integrated control unit 4000 and the control unit 3000 of this information. The attitude detection unit 235 detects the orientation (attitude) of the transport vehicle 10 (itself) based on a magnetic compass, information on the rotation speed of the left and right drive wheels, or steering information of the wheels.
[0095] The charge level detection unit 236 detects the charge level of the battery, which is the power source for the transport vehicle 10. If the charge level detected by the charge level detection unit 236 falls below a predetermined value, it is determined that charging is necessary, and the detection information of the decrease in charge level is recorded in the recording unit 220, and this information is notified to the central control unit 4000 and the control unit 3000. Furthermore, if it is detected that the charge level is below a predetermined value, in addition to the above process, the vehicle may be automatically moved to a charging spot to perform charging. The predetermined value for which the charge level detection unit 236 determines that charging is necessary may be a value that is set in advance based on at least one of the distance to the destination set for the transport vehicle 10 and the weight of the trolley 2000 connected to the transport vehicle 10. The angle detection unit 237 detects the attitude of the trolley 2000 relative to the transport vehicle 10 (for example, the relative angle α in Figure 1).
[0096] The input unit 240 consists of a physical switch or touch panel mounted on the transport vehicle 10, allowing the user to directly input operation commands to the transport vehicle 10. The display unit 250 consists of, for example, a liquid crystal panel mounted on the transport vehicle 10, and can display status information of the transport vehicle 10 (various detection information from the detection unit 230, type of driving mode, currently running operation scenario, etc.).
[0097] The control unit 260 includes an operation determination unit 261, a mode switching unit 262, a coupling control unit 263, a display control unit 264, a position estimation unit 265, and a driving control unit 266. Specifically, the control unit 260 functions as the operation determination unit 261, the mode switching unit 262, the coupling control unit 263, the display control unit 264, the position estimation unit 265, and the driving control unit 266 by executing a computer program stored in the recording unit 220.
[0098] The operation determination unit 261 determines the operation of the transport vehicle 10 based on the operation scenario of the transport vehicle obtained from the operation scenario management unit 4020. The mode switching unit 262 switches the driving mode of the transport vehicle 10 between guided driving mode and autonomous driving mode based on predetermined conditions such as the operation scenario or commands entered in the input unit 240. The coupling control unit 263 controls the operation of the coupling device 21 (Figure 1) to control coupling / uncoupling with the trolley 2000 based on predetermined conditions such as the operation scenario or commands entered in the input unit 240. The display control unit 264 controls the input IF of the input unit 240 and the display unit 250 as described above.
[0099] The position estimation unit 265 can estimate the position and attitude of the vehicle at a predetermined time, including its current position and attitude within the entire driving area, based on the distance traveled detected by the distance traveled detection unit 233, the orientation information of the vehicle detected by the attitude detection unit 235, and the map information of the entire area recorded in the recording unit 220. Alternatively, the position estimation unit 265 can also estimate the position and attitude of the vehicle within the entire driving area based on the distance and direction information from the vehicle to an object measured by the object position detection unit 12, and the map information of the entire area recorded in the recording unit 220. If the map information includes guidelines 111, the position and attitude relative to the guidelines 111 can also be estimated. Alternatively, if the transport vehicle 10 is traveling on guidelines 111 composed of two-dimensional codes, the position and attitude of the vehicle within the entire driving area can also be estimated based on the identification information of the two-dimensional codes and the map information. The position estimation unit 265 can also acquire position information using GNSS or the like installed on the transport vehicle 10.
[0100] The position estimation unit 265 can estimate the location of an object based on the estimated self-position information (vehicle position information) and the distance information from the vehicle to the object detected by the object position detection unit 12. It is also possible to estimate the installation position and extension angle of the guideline 111 based on the self-position information (vehicle position information) and attitude information when the line detection unit 16 detects the guideline 111.
[0101] The travel control unit 266 controls the movement of the transport vehicle 10 based on at least one of the determination information from the operation determination unit 261 and the mode switching unit 262. The travel control unit 266 can control the forward, reverse, stop, rotational movement, rotation, straight-line speed, rotational movement speed, and rotation speed of the transport vehicle 10. Specifically, the travel control unit 266 individually controls the right wheel drive unit 281 and the left wheel drive unit 282 of the wheel drive unit 280. The right wheel drive unit 281 and the left wheel drive unit 282 are composed of motors, for example, and by individually controlling the rotational speed and rotational direction of each drive wheel 13, it becomes possible to make the transport vehicle 10 curve and move along an arbitrary trajectory radius, or to rotate the transport vehicle 10 in place to change its direction.
[0102] The driving control unit 266 controls the drive wheels 13 by, for example, controlling the wheel drive unit 280, and executes the driving control method described with reference to Figures 1 to 6.
[0103] The control unit 260 can, for example, perform a travel control process to control the travel speed of the transport vehicle 10 when it moves along the guideline 111, based on the difference in distance between the current position of the transport vehicle 10 and the target position in the extending direction of the guideline 111. The travel control unit 266 may perform a distance estimation process to calculate the difference in distance between the current position of the transport vehicle 10 and the target position in the extending direction of the guideline 111, based on the current position information and target position information of the transport vehicle 10.
[0104] The distance estimation process can estimate the difference between the current position of the transport vehicle 10 and the target position in the direction extending of the guideline 111 by calculating the difference between the position coordinates of the transport vehicle 10 as current position information and the position coordinates of the target position as target position information.
[0105] Furthermore, the control unit 260 may perform travel control processing based on the distance to the target position when the transport vehicle 10 moves forward toward the target position, and if the transport vehicle 10 passes the target position, it may perform travel control processing to control the speed in the reverse direction based on the distance, similar to the case when moving forward. In this case, even if the transport vehicle passes the target position, it can reach the target position efficiently and with high precision while moving backward, just as it does when moving forward.
[0106] The control unit 260 may perform an angle estimation process to estimate the angle of the transport vehicle 10 with respect to the extending direction of the guideline 111 based on information from sensors installed on the transport vehicle 10, a relative position estimation process to estimate the relative position between the guideline 111 and the first specific point P1 of the transport vehicle 10 in a direction perpendicular to the extending direction of the guideline 111 based on information from sensors installed on the transport vehicle 10, and control the orientation of the transport vehicle 10 based on the angle and relative position of the transport vehicle 10. For example, in the case of an image recognition method in which a camera reads the guideline 111 using a two-dimensional code or barcode, in addition to the detection signal of the guideline 111, position information may be generated based on the information of the detected code, and relative angle information between the guideline 111 and the transport vehicle 10 (for example, angle β in Figure 1) may be generated by further analyzing the image information of the code. For example, the control unit 260 may control the transport vehicle 10 so that the angle (direction) of the transport vehicle 10 ultimately matches the extending direction of the guideline 111 (or the difference in angle is less than or equal to a predetermined value (e.g., 1°, 3°, 5°, etc.)), and so that the deviation between the guideline 111 and the transport vehicle 10 in a direction perpendicular to the extending direction of the guideline 111 is less than or equal to a predetermined value. For example, if it is determined that the deviation between the guideline 111 and the transport vehicle 10 in a direction perpendicular to the guideline 111 exceeds a predetermined value, the control unit 260 can control the transport vehicle 10 to move forward or backward, with its direction (angle) facing the guideline 111, so that the transport vehicle 10 approaches the guideline 111. Also, if the deviation between the guideline 111 and the transport vehicle 10 in a direction perpendicular to the guideline 111 is less than or equal to a predetermined value, the control unit 260 can control the transport vehicle 10 to face the same direction as the guideline 111.
[0107] The control unit 260 may calculate the distance from the current position to the target position based on the difference between the current position obtained from the position estimation unit 265 and the target position obtained from the recording unit 220 during the distance estimation process. Alternatively, it may perform image recognition on a two-dimensional code provided on the floor or wall and obtain the distance information (distance from the current position to the target position) associated with the two-dimensional code.
[0108] The control unit 260 may perform driving control processing based on speed information acquired by the speed sensor of the transport vehicle 10. The type of speed sensor is not particularly limited; any sensor, such as a sensor that detects the rotational speed or rotational speed of the drive wheels 13, or a camera can be used as a speed sensor. The control unit 260 can detect the speed of the transport vehicle 10 at predetermined intervals, determine whether the speed matches the target speed, and repeatedly adjust the driving control. That is, the control unit 260 determines whether the difference between the actual speed and the target speed is less than or equal to a predetermined value (a predetermined threshold, etc.), maintains control if it is less than or equal to the predetermined value, and can decelerate or accelerate to approach the target speed if it exceeds the predetermined value. By repeating this speed adjustment processing, deviations from the target speed can be suppressed (reduced).
[0109] The control unit 260 may also acquire information such as the current position, the distance to the destination position, and / or the target speed at that point by scanning a two-dimensional code installed on the road surface with a sensor (camera). For example, if target speed information is associated with the two-dimensional code, the transport vehicle 10 can acquire the target speed information from the two-dimensional code and perform the speed control described above.
[0110] Next, an example of a travel control method according to this embodiment will be described with reference to Figure 16. The travel control method is a method for controlling the travel of a transport vehicle 10 that travels by towing a trolley 2000 which is rotatably connected to the transport vehicle 10. Figure 16 is a flowchart of an example of a travel control method. As shown in Figure 16, the travel control method for the transport vehicle 10 includes steps S101 to S112.
[0111] First, in step S101, the control unit 260 starts the transport vehicle 10 moving in the direction D1.
[0112] Next, in step S102, the angle detection unit 237 starts detecting the relative angle α of the trolley 2000 with respect to the front-rear direction D20 of the transport vehicle 10. Then, the control unit 260 starts acquiring information indicating the relative angle α from the angle detection unit 237.
[0113] Next, in step S103, the control unit 260 determines whether a specific event has occurred. The specific event is a trigger for changing the direction of travel of the transport vehicle 10. The specific event is not particularly limited, but for example, it may be that the operation scenario requires a change in the direction of travel of the transport vehicle 10. Alternatively, for example, the specific event may be that the object position detection unit 12 has detected an object on the path of travel of the transport vehicle 10. The object may include, for example, obstacles, walls, and people.
[0114] If the result in step S103 is negative (NO), the control proceeds to step S112.
[0115] On the other hand, if the result in step S103 is positive (YES), the control proceeds to step S104.
[0116] Next, in step S104, the control unit 260 stops the transport vehicle 10.
[0117] Next, in step S105, the control unit 260 rotates the transport vehicle 10 so that the relative angle α becomes the initial angle θa.
[0118] Next, in step S106, the control unit 260 starts the transport vehicle 10 traveling in the direction along the front-rear direction D20 from a state where the relative angle α is the initial angle θa.
[0119] Next, in step S107, the control unit 260 causes the transport vehicle 10 to travel at the first speed V1.
[0120] Next, in step S108, the control unit 260 determines whether the relative angle α has become greater than or equal to a specific angle θb.
[0121] If the result in step S108 is negative (NO), the control returns to step S107.
[0122] On the other hand, if the result in step S108 is positive (YES), the control proceeds to step S109.
[0123] Next, in step S109, the control unit 260 accelerates the transport vehicle 10 from a first speed V1 to a second speed V2 which is greater than the first speed V1.
[0124] Next, in step S110, the control unit 260 determines whether the speed of the transport vehicle 10 has reached the second speed V2.
[0125] If the result in step S110 is negative (NO), the control returns to step S109.
[0126] On the other hand, if the result in step S110 is positive (YES), the control proceeds to step S111.
[0127] Next, in step S111, the control unit 260 causes the transport vehicle 10 to travel at the second speed V2.
[0128] Next, in step S112, the control unit 260 controls the movement of the transport vehicle 10 according to the operation scenario stored in the recording unit 220. When all operations defined in the operation scenario are completed, the movement control method ends.
[0129] As described above with reference to Figure 16, according to the travel control method of this embodiment, the target speed of the transport vehicle 10 is increased in steps according to the magnitude of the relative angle α of the trolley 2000 with respect to the longitudinal direction D20 of the transport vehicle 10 (steps S107 to S111). Therefore, when the transport vehicle 10 changes direction of travel, it is possible to suppress the sudden load on the transport vehicle 10, so the transport vehicle 10 is not required to generate a sudden torque and can start traveling smoothly.
[0130] Furthermore, in this embodiment, the control unit 260 stops the transport vehicle 10 (step S104) on the condition that the object position detection unit 12 detects an object (YES in step S103), and rotates the transport vehicle 10 from the stopped state so that the relative angle α becomes the initial angle θa (step S105). Then, the control unit 260 starts the transport vehicle 10 traveling in the direction along the front-rear direction D20 from the state where the relative angle α is the initial angle θa (step S106). Furthermore, the target speed of the transport vehicle 10 is increased in stages according to the magnitude of the relative angle α (steps S107 to S111). Therefore, when an object such as an obstacle is present on the travel path, it is possible to suppress the sudden load on the transport vehicle 10 when the transport vehicle 10 changes direction of travel.
[0131] Here, if the trolley 2000 is not connected to the transport vehicle 10, the control unit 260 does not need to gradually increase the target speed of the transport vehicle 10 when changing the direction of travel of the transport vehicle 10. In other words, in this case, the control unit 260 may start the transport vehicle 10 to travel after the transport vehicle 10 has rotated, and accelerate the transport vehicle 10 from a stopped state toward the third speed V3, without depending on the magnitude of the relative angle α. This is because if the trolley 2000 is not connected to the transport vehicle 10, there is no load on the transport vehicle 10 due to the trolley 2000. The third speed V3 is greater than the first speed V1. The third speed V3 may be the same as, for example, the second speed V2.
[0132] Furthermore, in Figure 16, the control unit 260 sets the target speed in two stages, such as the first speed V1 and the second speed V2. However, for example, the control unit 260 may set the target speed in three or more stages depending on the relative angle α.
[0133] (Modified Version) A modified version of the above embodiment will be described with reference to Figures 15 and 17. In the modified version, the travel control parameters (e.g., second speed V2) used when changing the direction of travel of the transport vehicle 10 are changed according to the load on the transport vehicle 10 (e.g., the weight of the trolley 2000 and the load). The differences between the modified version and the above embodiment will be mainly described below.
[0134] The control unit 260 shown in Figure 15 sets direction change control information according to the traction load information. Therefore, the control unit 260 can change the direction change control information according to the traction load information.
[0135] The towing load information indicates the load applied to the transport vehicle 10 when the transport vehicle 10 tows the trolley 2000.
[0136] Specifically, the towing load information includes information indicating the weight of the trolley 2000, information indicating the weight of the load on the trolley 2000, or information indicating the weight of both the trolley 2000 and the load.
[0137] The information indicating the weight of the trolley 2000 may be, for example, the weight of the trolley 2000 itself, or a physical quantity correlated with the weight of the trolley 2000. In this case, the physical quantity may be, for example, the load applied to the transport vehicle 10 when it pulls the trolley 2000.
[0138] The information indicating the weight of the load on the trolley 2000 may be the weight of the load on the trolley 2000 itself, or it may be a physical quantity correlated with the weight of the load on the trolley 2000. In this case, the physical quantity may be, for example, the load attributable to the load among the load applied to the transport vehicle 10 when the transport vehicle 10 pulls the trolley 2000 loaded with the load.
[0139] The information indicating the weight of the trolley 2000 and the load may be the sum of the weight of the trolley 2000 and the weight of the load, or it may be a physical quantity that correlates with the sum of the weight of the trolley 2000 and the weight of the load. In this case, the physical quantity may be, for example, the load applied to the transport vehicle 10 when the transport vehicle 10 pulls the trolley 2000 loaded with the load.
[0140] The units of the above physical quantities are not particularly limited and may be, for example, units related to mass (such as kg), or units of the output value output by a load sensor.
[0141] The direction change control information indicates the travel control parameters when changing the direction of travel of the transport vehicle 10.
[0142] Specifically, the travel control parameters include at least one of the following: a first speed V1, a second speed V2, acceleration A1 from when the transport vehicle 10 is stopped until it reaches the first speed V1, acceleration A2 from when the transport vehicle 10 reaches the second speed V2, and a specific angle θb.
[0143] For example, the control unit 260 sets the travel control parameters (excluding the specific angle θb) to smaller values as the load indicated by the traction load information increases. And / or, for example, the control unit 260 sets the travel control parameters (specific angle θb) to larger values as the load indicated by the traction load information increases. As a result, the sudden load on the transport vehicle 10 when it changes direction can be suppressed.
[0144] Next, an example of a modified travel control method will be described with reference to Figure 17. Figure 17 is a flowchart showing an example of a modified travel control method. As shown in Figure 17, the travel control method for the transport vehicle 10 includes steps S201 to S214.
[0145] First, steps S201 to S203 are executed. Steps S201 to S203 are the same as steps S101 to S103 in Figure 16, respectively.
[0146] If the result in step S203 is negative (NO), the control proceeds to step S214.
[0147] On the other hand, if the result in step S203 is positive (YES), the control proceeds to step S204.
[0148] Next, in step S204, the control unit 260 acquires traction load information.
[0149] For example, the weight of the trolley 2000 is pre-stored in the recording unit 220. In this case, the control unit 260 obtains the weight information of the trolley 2000 from the recording unit 220. Alternatively, the weight of the load may be pre-stored in the recording unit 220. In this case, the control unit 260 obtains the weight information of the load on the trolley 2000 from the recording unit 220.
[0150] For example, a load cell is installed on the coupling device 21 (for example, the coupling body 22). The load cell detects the load applied to the transport vehicle 10 due to the trolley 2000 and the load. Alternatively, for example, multiple load cells are installed on the loading platform of the trolley 2000. The multiple load cells detect the load due to the load placed on the loading platform.
[0151] Information indicating the load detected by the load cell is transmitted to the transport vehicle 10 via communication equipment mounted on the trolley 2000, either through the central control unit 4000 and the communication network 6000, or directly. The control unit 260 receives the information indicating the load.
[0152] For example, the control unit 260 estimates the load on the transport vehicle 10 due to the trolley 2000 and its load, based on the power consumption (current × voltage) of the motor of the wheel drive unit 280. Specifically, the power consumption of the motor increases as the load on the transport vehicle 10 increases. For example, the power consumption of the motor is approximately proportional to the load on the transport vehicle 10. Therefore, the control unit 260 can estimate the load on the transport vehicle 10 based on the power consumption of the motor of the wheel drive unit 280.
[0153] Next, in step S205, the control unit 260 sets direction change control information according to the traction load information. Therefore, according to the modified example, the control unit 260 can set the travel control parameters (excluding the specific angle θb) to smaller values as the load indicated by the traction load information increases. For example, the control unit 260 can set the travel control parameters (specific angle θb) to larger values as the load indicated by the traction load information increases. As a result, the sudden load on the transport vehicle 10 when it changes direction can be suppressed more effectively. Therefore, the transport vehicle 10 is not required to generate sudden torque and can start traveling smoothly.
[0154] Next, steps S206 to S214 are executed. Steps S206 to S214 are the same as steps S104 to S112 in Figure 16, respectively. Then, once all operations defined in the operation scenario are completed, the driving control method is terminated.
[0155] Here, the direction change control information may include at least one of the following: a first speed V1, a second speed V2, acceleration A1 from when the transport vehicle 10 is stopped until it reaches the first speed V1, acceleration A2 from when the transport vehicle 10 reaches the second speed V2, a specific angle θb, and additional control information.
[0156] The additional control information includes information on the target speed Vn after the transport vehicle 10 reaches the second speed V2, and information on the target angle θn of the relative angle α, which is the condition for starting acceleration when accelerating the transport vehicle 10 from the second speed V2 to the target speed Vn. The additional control information may also include information on the acceleration An when accelerating the transport vehicle 10 toward the target speed Vn.
[0157] In this case, the control unit 260 accelerates the transport vehicle 10 toward the target speed Vn when the relative angle α becomes greater than or equal to the target angle θn after the transport vehicle 10 has reached the second speed V2. In this case, the control unit 260 may change at least one of the following pieces of information: the first speed V1, the second speed V2, acceleration A1, acceleration A2, and the specific angle θb, depending on the content of the additional control information.
[0158] Furthermore, the target velocity Vn, target angle θn, and acceleration An are not limited to one each, but may be set to multiple values.
[0159] While preferred embodiments of the present disclosure have been described in detail above with reference to the attached drawings, the technical scope of the present disclosure is not limited to such examples. It is clear to any person with ordinary skill in the art of the present disclosure that various modifications or alterations may be conceived within the scope of the technical idea set forth in the claims, and these will naturally also fall within the technical scope of the present disclosure.
[0160] The devices described herein may be implemented as single devices, or they may be implemented by multiple devices (e.g., cloud servers) that are partially or entirely connected via a network. For example, the control unit 260 and recording unit 220 of the transport vehicle may be implemented by different servers connected to each other via a network, or they may be implemented by, for example, the overall control unit 4000 of the transport system 1000. Furthermore, in the transport system 1000 described herein, an example was described in which the pilot 3000, the overall control unit 4000, and the input / output device 5000 are each composed of separate hardware connected via a network, but some or all of the functions of the pilot 3000, the overall control unit 4000, and the input / output device 5000 may be implemented in the transport vehicle 10.
[0161] The series of processes performed by the apparatus described herein may be implemented using software, hardware, or a combination of software and hardware. Computer programs for implementing each function of the control unit 260 according to this embodiment can be created and implemented on a PC or the like. Furthermore, a computer-readable recording medium containing such a computer program can also be provided. Examples of recording media include magnetic disks, optical disks, magneto-optical disks, and flash memory. Alternatively, the computer program may be distributed without using a recording medium, for example, via a network.
[0162] In Figures 2 to 6, 16 and 17, the control unit 260 executes each step included in the driving control method by executing a computer program stored in the recording unit 220. In other words, the computer program causes the control unit 260 to execute each step included in the driving control method. The control unit 260 corresponds to an example of the "computer" in this disclosure. To put it another way, the computer program product realizes each step included in the driving control method when the computer program is executed by the control unit 260.
[0163] Furthermore, the effects described herein are merely descriptive or illustrative and not limiting. In other words, the technology relating to this disclosure may produce other effects that are obvious to those skilled in the art from the description herein, in addition to or instead of the effects described herein.
[0164] Furthermore, the following configurations also fall within the technical scope of this disclosure.
[0165] (Item 1) A travel control system for a transport vehicle that travels while towing an object to be transported, which is rotatably connected to the transport vehicle, comprising an angle detection unit for detecting the relative angle of the object to be transported with respect to the front-rear direction of the transport vehicle, the system starting the transport vehicle to travel in the direction along the front-rear direction from a state where the relative angle is an initial angle, the system driving the transport vehicle at a first speed until the relative angle becomes a specific angle greater than the initial angle, and when the relative angle becomes greater than or equal to the specific angle, the system accelerating the transport vehicle from the first speed to a second speed greater than the first speed.
[0166] (Item 2) The driving control system described in Item 1, wherein the initial angle is approximately 90 degrees.
[0167] (Item 3) A travel control system according to Item 1 or Item 2, wherein the transport vehicle is rotated from a stopped state so that the relative angle becomes the initial angle, and the transport vehicle starts traveling in the direction along the front-rear direction from the state where the relative angle is the initial angle.
[0168] (Item 4) The driving control system according to any one of Items 1 to 3, wherein the specified angle is an angle of approximately 110 degrees or more and approximately 120 degrees or less.
[0169] (Item 5) A driving control system according to any one of Items 1 to 4, further comprising an object detection unit that detects an object without contact, wherein, on the condition that the object detection unit detects the object, the transport vehicle is stopped, the transport vehicle is rotated from the stopped state so that the relative angle becomes the initial angle, and the transport vehicle starts to travel in the direction along the front-rear direction from the state where the relative angle is the initial angle.
[0170] (Item 6) A driving control system according to any one of Items 1 to 5, wherein the driving control system sets direction change control information according to the towing load information, the towing load information is information indicating the weight of the object to be transported, information indicating the weight of the load on the object to be transported, or information indicating the weight of the object to be transported and the load, the direction change control information includes at least one of the following: the first speed, the second speed, the acceleration from when the transport vehicle is stopped until it reaches the first speed, the acceleration from the first speed until the transport vehicle reaches the second speed, the specific angle, and additional control information, the additional control information includes information on the target speed after the transport vehicle's speed reaches the second speed, and the target angle of the relative angle which is the condition for starting acceleration when accelerating the transport vehicle from the second speed to the target speed.
[0171] (Item 7) A method for controlling the travel of a transport vehicle that travels while towing an object to be transported which is rotatably connected to the transport vehicle, the method comprising: starting the transport vehicle to travel in the direction along the front-rear direction from a state in which the relative angle of the object to be transported with respect to the front-rear direction of the transport vehicle is an initial angle; traveling the transport vehicle at a first speed until the relative angle becomes a specific angle greater than the initial angle; and, when the relative angle becomes greater than or equal to the specific angle, accelerating the transport vehicle from the first speed to a second speed greater than the first speed.
[0172] (Item 8) A program that causes a computer to execute a method for controlling the movement of a transport vehicle that tows an object to be transported which is rotatably connected to the transport vehicle, the method comprising: a step of starting the transport vehicle to move in a direction along the front-rear direction from a state in which the relative angle of the object to be transported with respect to the front-rear direction of the transport vehicle is an initial angle; a step of driving the transport vehicle at a first speed until the relative angle becomes a specific angle greater than the initial angle; and a step of accelerating the transport vehicle from the first speed to a second speed greater than the first speed when the relative angle becomes greater than or equal to the specific angle.
[0173] This disclosure provides a vehicle travel control system, a travel control method, and a program, and has industrial applicability.
[0174] 10 Transport vehicle, 12 Object position detection unit (object detection unit), 13 Drive wheels, 14 Non-drive wheels, 16 Line detection unit, 17 Magnetic sensor, 21 Coupling device, 111 Guideline, 132 Driving mode switching position, 210 Communication unit, 220 Recording unit, 230 Detection unit, 237 Angle detection unit, 240 Input unit, 250 Display unit, 260 Control unit, 280 Wheel drive unit, 1000 Transport system (driving control system), 2000 Trolley (object to be transported), 3000 Driver, 4000 Integrated control unit, 5000 Input / output device, 6000 Communication network, 7000 External system
Claims
A travel control system for a transport vehicle that travels while towing an object to be transported, which is rotatably connected to the transport vehicle, The transport vehicle is equipped with an angle detection unit that detects the relative angle of the transported object with respect to the front-rear direction of the transport vehicle, Starting from the state where the relative angle is the initial angle, the transport vehicle begins to travel in the direction along the front-rear direction. The transport vehicle is driven at a first speed until the relative angle becomes a specific angle greater than the initial angle. A driving control system that accelerates the transport vehicle from the first speed to a second speed greater than the first speed when the relative angle exceeds the specified angle. The driving control system according to claim 1, wherein the initial angle is approximately 90 degrees. The transport vehicle is rotated from a stationary position so that the relative angle becomes the initial angle. A travel control system according to claim 1 or claim 2, wherein the transport vehicle starts traveling in the direction along the front-rear direction from a state in which the relative angle is the initial angle. The driving control system according to claim 1 or claim 2, wherein the specified angle is an angle of approximately 110 degrees or more and approximately 120 degrees or less. It further includes an object detection unit that detects objects without contact, If the object detection unit detects the object, the transport vehicle is stopped, and the transport vehicle is rotated from the stopped state so that the relative angle becomes the initial angle. A travel control system according to claim 1 or claim 2, wherein the transport vehicle starts traveling in the direction along the front-rear direction from a state in which the relative angle is the initial angle. Direction change control information is set according to the towing load information. The towing load information is information indicating the weight of the object to be transported, information indicating the weight of the load on the object to be transported, or information indicating the weight of both the object to be transported and the load. The direction change control information includes at least one of the following: the first speed, the second speed, the acceleration from when the transport vehicle is stopped until it reaches the first speed, the acceleration from when the transport vehicle reaches the second speed until it reaches the first speed, the specific angle, and additional control information. The travel control system according to claim 1 or 2, wherein the additional control information includes information on the target speed after the speed of the transport vehicle reaches the second speed, and the target angle of the relative angle which is the condition for starting acceleration when accelerating the transport vehicle from the second speed to the target speed. A method for controlling the movement of a transport vehicle that travels while towing an object to be transported, which is rotatably connected to the transport vehicle, The steps include: starting the transport vehicle to travel in the direction along the front-rear direction from a state where the relative angle of the object to be transported with respect to the front-rear direction of the transport vehicle is the initial angle; The steps include: driving the transport vehicle at a first speed until the relative angle becomes a specific angle greater than the initial angle; A driving control method comprising the step of accelerating the transport vehicle from the first speed to a second speed greater than the first speed when the relative angle becomes greater than or equal to the specified angle. A program that causes a computer to execute a method for controlling the movement of a transport vehicle that tows an object to be transported, which is rotatably connected to the transport vehicle, The aforementioned driving control method is: The steps include: starting from a state where the relative angle of the object to be transported with respect to the front-rear direction of the transport vehicle is the initial angle, the transport vehicle begins to travel in a direction along the front-rear direction; The steps include: driving the transport vehicle at a first speed until the relative angle becomes a specific angle greater than the initial angle; A program that includes the step of accelerating the transport vehicle from the first speed to a second speed greater than the first speed when the relative angle becomes greater than or equal to the specified angle.
Citation Information
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