JP7143773B2 - Turn control method and turn control device - Google Patents

Description

The present invention relates to a swing control method and a swing control device.

As a conventional turning control method for an unmanned towing vehicle, for example, the technique described in Patent Document 1 is known. In Patent Document 1, the towing vehicle travels so as to follow the guide line while towing the vehicle to be towed. When the tow vehicle reaches a point where the guide line it is following and another guide line cross each other, it turns before the intersection and transfers to another guide line. After that, the towing vehicle travels so as to follow another guide line.

Japanese Patent Publication No. 8-20901

In the turning control method described above, the towing vehicle passes through the inner peripheral portion between the guide lines that intersect each other. In this case, since there is an inner wheel difference between the towing vehicle and the towed vehicle, the towed vehicle needs to make a large turn inward in the vicinity of the intersection. In addition, the towed vehicle must travel a long distance before it becomes parallel to the guide line to which it has transferred. In this way, various problems arise when the towed vehicle makes a large turn, so it is required that the towed vehicle makes a small turn when turning.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a turning control method and a turning control device capable of making the motion of a towed vehicle in a tight turn.

A turning control method according to an aspect of the present invention turns a towed vehicle that travels in a traveling direction following a first guide line while towing a towed vehicle, thereby turning a second vehicle that intersects the first guide line. A turning control method for transferring to the second guide line, comprising a turning step of autonomously turning the tractor in a region downstream of the second guide line in the direction of travel.

The turning control method includes a turning step of autonomously turning the towing vehicle in a region downstream of the second guide line in the traveling direction. When the towing vehicle turns in a region downstream of the second guide line in the traveling direction, the towing vehicle makes a large turn. In this case, the towed vehicle towed on the upstream side in the direction of travel of the towing vehicle is near the intersection of the first guide line and the second guide line by reducing the influence of the inner wheel difference with the tow vehicle. You can change direction with a small turn. As described above, the motion of the towed vehicle at the time of turning can be reduced to a small radius.

The turning control method further includes a follow-up travel step of causing the tow vehicle to follow the first guide line for a certain distance after detecting the mark while the tow vehicle is traveling following the first guide line. In addition, the follow-up travel step may be switched to the turning step in a region downstream of the second guide line in the traveling direction. In this way, the tractor follows the first guide line for a certain distance instead of automatically running immediately after detecting the mark. Thus, using the first guide line, it is possible to change the distance that the towing vehicle is caused to travel to a region downstream of the second guide line in the traveling direction according to the dimensions of the towed vehicle. To switch to a turning step at an ideal position without changing the mark position even if a plurality of different towed vehicles exist.

In the turning control method, in the turning step, the connecting portion between the towing vehicle and the towed vehicle turns around a virtual point where the distance from the first guide line is equal to the distance from the second guide line. , the tow vehicle may be turned. In this way, by causing the connecting portion to turn around the center of rotation, the movement of the towed vehicle can be made a small turn, and the center line and the second guide line after turning of the towed vehicle can be achieved. deviation can be minimized.

In the turn control method, at the start of the turning step, the towing vehicle may be rotated about the connection between the towing vehicle and the towed vehicle to turn. The tow vehicle can make turns without moving the towed vehicle. In this case, there is no need to consider the trajectory of the towed vehicle when the towed vehicle changes direction, and the amount of movement of the towed vehicle can be reduced. As a result, it is possible to simplify the content of processing for autonomous travel, and to make the towed vehicle move in a small radius.

In the turning control method, a plurality of constant distance parameters may be stored, and the step switching point for switching from the following travel step to the turning step may be changed based on the dimensional information of the towed vehicle. In this case, the turning can be started at a position according to the dimensions of the towed vehicle.

In the turning control method, a plurality of constant distance parameters are stored, and the step switching point for switching from the following travel step to the turning step is changed based on the dimensional information of the towed vehicle. In this case, it is possible to switch to the turning step at a timing according to the dimensions of the towed vehicle.

A turning control device according to one aspect of the present invention turns a towed vehicle that travels in a traveling direction following a first guide line while towing a towed vehicle, thereby turning a second guide line that intersects the first guide line. A turning control device for transferring to the second guide line, which performs control to turn the towing vehicle by autonomous travel in a region downstream of the second guide line in the direction of travel.

According to this turning control device, it is possible to obtain the same functions and effects as those of the turning control method described above.

ADVANTAGE OF THE INVENTION According to this invention, the turning control method and turning control apparatus which can make the motion of a towed vehicle at the time of turning into a small turn can be provided.

FIG. 4 is a side view of a transport vehicle that makes a turn by the turning control method according to the present embodiment; 2 is a schematic configuration diagram of a transport vehicle shown in FIG. 1; FIG. 4 is a flow chart showing a turning control method according to the embodiment; FIG. 5 is a schematic plan view showing the state of the transport vehicle at each timing during turning; FIG. 5 is a schematic plan view showing the state of the transport vehicle at each timing during turning; FIG. 5 is a schematic plan view showing the state of the transport vehicle at each timing during turning; FIG. 11 is a schematic plan view showing the movement of a carrier employing a turning control method according to a comparative example; FIG. 11 is a schematic plan view showing the movement of a carrier employing a turning control method according to a comparative example;

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a side view of a transport vehicle 100 that turns by the turning control method according to this embodiment. FIG. 2 is a schematic configuration diagram of the carrier 100 shown in FIG. As shown in FIGS. 1 and 2, the transport vehicle 100 includes a tractor 1 that runs unmanned and a towed vehicle 2 that is towed by the tractor 1 with a load.

The towing vehicle 1 has one or more slewing wheels 3 having a rotating shaft for turning and two or more fixed wheels 4 having no rotating shaft for turning. In this embodiment, the towing vehicle 1 has one turning wheel 3 on the front side of the vehicle body 6 and two fixed wheels 4 on the rear side of the vehicle body 6 . The towed vehicle 2 has one or more slewing wheels 7 having a rotating shaft for turning and two or more fixed wheels 8 having no rotating shaft for turning. In this embodiment, the towed vehicle 2 has two turning wheels 7 on the front side of the vehicle body 9 and two fixed wheels 8 on the rear side of the vehicle body 9 . The slewing wheels 3 and 7 rotate in plan view (viewpoint shown in FIG. 2) in accordance with the traveling direction. The fixed wheels 4 and 8 are immovable in plan view regardless of the traveling direction.

The vehicle 2 to be towed has a traction lever 11 extending forward from the front end of the vehicle body 9 . A front end portion of the towing lever 11 is rotatably connected to the vehicle body 6 of the towing vehicle 1 via a connecting portion 12 . The vehicle 2 to be towed is towed by the towing vehicle 1 via the connecting portion 12 . The towed vehicle 2 is relatively rotatable with respect to the towing vehicle 1 in a plan view, with the connecting portion 12 as the center. The connecting portion 12 is arranged at a substantially central position in the width direction of the vehicle body 6 . In addition, the connecting portion 12 is arranged at a position overlapping the axle AX1 of the fixed wheel 4 or in the vicinity of the axle AX1 in the longitudinal direction of the vehicle body 6 .

The towing vehicle 1 includes an induction sensor 13 and a mark sensor 14 on the lower surface side of the vehicle body 6. - 特許庁The guidance sensor 13 is a sensor that detects guidance lines TL1 and TL2 (see FIG. 4A) formed on the road surface. The guidance sensor 13 has a shape extending in the width direction so that the guidance lines TL1 and TL2 can be detected within a certain range in the width direction of the vehicle body 6 . The mark sensor 14 is a sensor that detects marks MK (see FIG. 4A) placed on the road surface. The mark sensor 14 is provided on at least one end side of the vehicle body 6 in the width direction. The details of the induction sensor 13 and the mark sensor 14 will be described later along with their operations.

As shown in FIG. 2, the towing vehicle 1 has a control device 20 (swing control device). The control device 20 includes an ECU [Electronic Control Unit] for overall control of the device. The ECU is an electronic control unit having a CPU [Central Processing Unit], a ROM [Read Only Memory], a RAM [Random Access Memory], a CAN [Controller Area Network] communication circuit, and the like. In the ECU, for example, programs stored in the ROM are loaded into the RAM, and the programs loaded into the RAM are executed by the CPU, thereby realizing various functions. The ECU may consist of a plurality of electronic units. The control device 20 includes an information acquisition section 21 , a travel control section 22 and a storage section 23 .

The information acquisition unit 21 acquires detection results from the guidance sensor 13 and the mark sensor 14 . The travel control unit 22 performs travel control of the towing vehicle 1 based on the information acquired by the information acquisition unit 21 . The travel control unit 22 performs travel control based on the detection result from the guidance sensor 13 when the towing vehicle 1 follows the guide lines TL1 and TL2. When the towing vehicle 1 makes a turn, the traveling control unit 22 performs turning control to turn the towing vehicle 1 by autonomous traveling. The storage unit 23 stores various information for controlling the towing vehicle 1 . The storage unit 23 stores information for the towing vehicle 1 to make turns in autonomous travel.

The steering method of the towing vehicle 1 is not particularly limited, and either a steered wheel method or a two-wheel speed difference method may be employed. The steered wheel system is a system in which the towing vehicle 1 turns by rotating the turning wheel 3 with a steering motor in accordance with the traveling direction. In this case, at least one of the slewing wheel 3 and the fixed wheel 4 serves as a driving wheel rotated by the traveling motor. The travel control unit 22 controls the turning motion of the towing vehicle 1 by controlling the steering motor. The two-wheel speed difference method is a method in which the left and right fixed wheels 4 are driven by separate traveling motors and the towing vehicle 1 turns by providing a speed difference to each fixed wheel 4 . The travel control unit 22 controls the turning motion of the towing vehicle 1 by controlling the speed of each travel motor.

Next, a turning control method according to the present embodiment will be described with reference to FIGS. 3 and 4 to 6. FIG. In this turning control method, the towed vehicle 1 turns while towing the towed vehicle 2, following the first guide line TL1 and traveling in the first traveling direction D1 (advancing direction). This is a control method for transferring to the second guide line TL2 that intersects the line TL1. FIG. 3 is a flow chart showing a turning control method according to this embodiment. Note that the flowchart shown in FIG. 3 shows an example of processing contents in the turning control method, and the processing contents may be changed as appropriate. 4 to 6 are schematic plan views showing the state of the transport vehicle 100 at each timing during turning.

First, in this embodiment, the configuration of the road surface where the towing vehicle 1 turns will be described. As shown in FIG. 4A, at this location, the linearly extending first guide line TL1 and the linearly extending second guide line TL2 intersect each other perpendicularly. The first guide line TL1 and the second guide line TL2 are lines for guiding the towing vehicle 1 to follow the guide lines TL1 and TL2. The guide wires TL1, TL2 may be formed of magnetic tape or the like, and in this case, the guide sensor 13 detects magnetism from the guide wires TL1, TL2. The guide lines TL1 and TL2 may be lines drawn in a color different from that of the road surface. In this case, the guide sensor 13 optically detects the guide lines TL1 and TL2. The towing vehicle 1 travels in the first traveling direction D1 along the first guide line TL1, and after transferring to the second guide line TL2, travels along the second guide line TL2 to the second direction. It travels in the traveling direction D2. Here, the region on the upstream side in the first traveling direction D1 of the second guide line TL2 is defined as a "first region E1", and the region on the downstream side thereof is defined as a "second region E2".

The mark MK is a mark indicating that the towing vehicle 1 has approached a turning position. The mark MK is formed in the vicinity of the first guide line TL1 in the first region E1 and in front of the intersection with the second guide line TL2. The mark MK is formed at a position spaced downstream from the second guide line TL2 in the first traveling direction D1. The mark MK is formed downstream of the first guide line TL1 in the second traveling direction D2, but may be formed upstream. The mark sensor 14 may magnetically, electrically, or optically detect the mark MK.

In the stage before the process shown in FIG. 3 is started, as shown in FIG. Travel in direction D1. At the timing when the towing vehicle 1 reaches the position where the mark MK is detected by the mark sensor 14, the process shown in FIG. 3 is started. The control device 20 detects the mark MK at a position on the first guide line TL1 on the upstream side of the second guide line TL2 in the first traveling direction D1 (that is, the first region E1). After that, a follow-up travel step S10 is executed in which the tractor 1 travels a certain distance following the first guide line TL1.

In following travel step S10, as shown in FIG. 4B, the control device 20 causes the vehicle to follow the first guide line TL1 even when the guide sensor 13 reaches the position of the second guide line TL2. continue. The control device 20 continues the following travel step S10 until the towing vehicle 1 reaches the position shown in FIG. 4(c). The control device 20 controls the position of the first guide line TL1 downstream of the second guide line TL2 in the first traveling direction D1 (that is, the second region E2) from the follow-up traveling step S10 to the turning described later. Switch to step S50. When the switching is performed, the induction sensor 13, the axle AX1 of the rear wheels, and the connecting portion 12 are positioned in the second region E2.

Specifically, the towing vehicle 1 performs the follow-up traveling step S10 until the axle AX2 of the fixed wheel 8, which is the rear wheel of the towed vehicle 2, reaches the position of the rotation center CP in the first traveling direction D1. Run. The center of rotation CP is an imaginary point whose distance from the first guide line TL1 is equal to the distance from the second guide line TL2. Let the distance at this time be "distance L1." The center of rotation CP is separated from the first guide line TL1 by a distance L1 in the second traveling direction D2. The center of rotation CP is separated from the second guide line TL2 by a distance L1 in the direction opposite to the first traveling direction D1. In this embodiment, the distance L1 is set to the distance between the front and rear wheels of the vehicle 2 to be towed. However, the distance L1 is a value that can be arbitrarily set depending on the size and shape of the transport vehicle 100 and the positional relationship of surrounding obstacles. Note that the lower limit of the distance L1 can be set to, for example, half the wheelbase of the fixed wheels 8 of the towed vehicle 2 . In addition, since the angle formed by the towing vehicle 1 and the towed vehicle 2 becomes large in FIG. 11 is short, or depending on the shape of the vehicle to be towed 2, the distance L1 may be set larger in consideration of the situation.The upper limit of the distance L1 is not particularly limited, but is within a range in which interference does not occur. Note that the fixed distance that the towing vehicle 1 travels following the first guide line TL1 after the mark sensor 14 detects the mark MK is the distance L4 shown in FIG. The distance L4 is obtained by subtracting the distance L1 from the distance between the axle AX2 and the second guide line TL2 when the mark sensor 14 detects the mark MK. is detected, followed by the towing vehicle 1 for a distance L4.

Note that the distance L4 is stored in the storage unit 23 . A plurality of these numerical values may be stored according to the dimensions of the bogie of the towed vehicle 2 . The size of the towed vehicle 2 connected to the towing vehicle 1 can be notified by radio, and an RFID antenna is installed at the connecting part to read the information of the RFID attached to the towed vehicle 2 side. It is also possible to grasp the dimensions by, for example, The control device 20 changes the step switching point for switching from the following travel step S10 to the turning step S50 based on the dimension information of the towed vehicle 2 . That is, it is possible to change how long the follow-up travel is performed according to the dimensions of the towed vehicle 2 .

Next, the control device 20 executes a turning step S50 in which the tractor 1 turns by autonomous traveling in a second region E2 downstream of the second guide line TL2 in the first traveling direction D1. The turning step S50 includes a turning step S20, a turning step S30, and a turning step S40. Note that the program table for autonomous travel in the turning step S<b>50 is stored in the storage unit 23 . Therefore, the control device 20 reads out the program table from the storage unit 23 and executes the program. Autonomous driving is not a driving method that follows the guidance line while reading it with the guidance sensor 13, but the towing vehicle 1 runs based on a program in which the angle and distance are set in advance, regardless of the guidance line. It is a running method that allows

As shown in FIG. 5(a), the control device 20 causes the towing vehicle 1 to rotate about the connecting portion 12 between the towing vehicle 1 and the towed vehicle 2 at the start of the turning step S50 to change direction. , the direction change step S20 is executed. In the direction change step S20, the control device 20 controls so that only the towing vehicle 1 turns around the connecting portion 12 on the spot so that the towed vehicle 2 does not move. When the steered wheel system is employed, the control device 20 steers the axle AX3 of the turning wheel 3 of the towing vehicle 1 by 90°. When adopting the two-wheel speed difference method, the left and right fixed wheels 4 are set to rotate in opposite directions. Incidentally, even when the two-wheel speed difference method is adopted, the axle AX3 of the slewing wheel 3 rotates by 90°. The control device 20 changes the direction of the towing vehicle 1 until the extension of the axle AX1 of the fixed wheel 4 of the towing vehicle 1 passes through the center of rotation CP. The control device 20 changes from the state shown in FIG. 4C to the state shown in FIG. You can judge that

After the turning step S20, the control device 20 executes the turning step S30. In the turning step S30, the controller 20 causes the tractor 1 to turn until the transport vehicle 100 changes from the state shown in FIG. 5(a) to the state shown in FIG. 5(b). In the turning step S30, the control device 20 turns the towing vehicle 1 so that the connecting portion 12 between the towing vehicle 1 and the towed vehicle 2 turns around the center of rotation CP. The turning radius of the connecting portion 12 corresponds to the length of a straight line connecting the connecting portion 12 and the center of rotation CP. In the state shown in FIG. 5A, the dimension of the straight line in the first traveling direction is indicated by distance L2, and the dimension in the second traveling direction is indicated by distance L1. Therefore, the turning radius of the connecting portion 12 is obtained by the square root of "(distance L1) ² +(distance L2) ² ". A distance L2 is the distance between the connecting portion 12 and the axle AX2 of the fixed wheel 8 . Distance L2 is a unique value of towed vehicle 2 . It should be noted that not only the connecting portion 12 but also each portion of the towing vehicle 1 and the towed vehicle 2 rotate around the center of rotation CP.

When the steered wheel system is employed, the control device 20 steers the slewing wheel 3 so that the extension of the axle AX3 of the slewing wheel 3 of the towing vehicle 1 passes through the center of rotation CP, and maintains this state. to make the tractor 1 turn. When adopting the two-wheel speed difference method, the control device 20 rotates the fixed wheel 4 so that the speed ratio between the fixed wheel 4 on the inner peripheral side and the fixed wheel 4 on the outer peripheral side becomes "distance L3: distance L3 + dimension T". Control speed. A distance L3 is the distance between the center of rotation CP and the central position of the fixed ring 4 on the inner peripheral side. A dimension T is a dimension between the fixed ring 4 on the inner peripheral side and the fixed ring 4 on the outer peripheral side. The distance L3 is a value that varies depending on the set value of the distance L1. Dimension T is a characteristic value of tractor 1 . Even when the two-wheel speed difference method is adopted, the extension of the axle AX3 of the slewing wheel 3 passes through the center of rotation CP. The control device 20 causes the tractor 1 to turn until the connecting portion 12 reaches the second guide line TL2 or near the second guide line TL2.

Note that there is a timing at which the guidance sensor 13 detects the second guidance line TL2 between the state shown in FIG. 5(a) and the state shown in FIG. 5(b). If the guidance sensor 13 fails to detect the second guidance line TL2 during the turning step S30, the control device 20 may determine an abnormality and stop the automatic operation of the towing vehicle 1. Note that the abnormality determination may also be performed while the state shown in FIG. 4(b) changes to the state shown in FIG. 4(c).

As shown in FIG. 6, the control device 20 rotates the towing vehicle 1 about the connecting portion 12 between the towing vehicle 1 and the towed vehicle 2 at the end of the turning step S50, that is, after the turning step S30 is completed. Then, the direction change step S40 is executed by changing the direction. In the direction change step S40, the control device 20 controls so that only the towing vehicle 1 turns around the connecting portion 12 on the spot so that the towed vehicle 2 does not move. When the steered wheel system is employed, the control device 20 steers the axle AX3 of the turning wheel 3 of the towing vehicle 1 by 90°. When adopting the two-wheel speed difference method, the left and right fixed wheels 4 are set to rotate in opposite directions. Incidentally, even when the two-wheel speed difference method is adopted, the axle AX3 of the slewing wheel 3 rotates by 90°. The control device 20 performs the direction change step S40 until the orientation of the towing vehicle 1 coincides with the second traveling direction D2. The control device 20 stops the direction change at the position where the guidance sensor 13 detects the second guidance line TL2 at the center position.

As described above, the control process shown in FIG. 3 is completed, and transfer of the transport vehicle 100 to the second guide line TL2 is completed. After that, the towing vehicle 1 travels in the second traveling direction D2 so as to follow the second guide line TL2.

Note that the parameters for the above control may be stored in advance in the storage unit 23 as fixed values. For example, the distances L1, L3 and other calculated values may be stored in the storage unit 23 in advance. Alternatively, parameters such as the distances L1 and L3 may be sent to the control device 20 via communication at the required timing, and other calculated values may be calculated by the control device 20 each time. For example, when there are multiple types of towed vehicles 2, it is effective to use communication.

Next, the operation and effects of the turning control method and the control device 20 according to this embodiment will be described.

First, a turning control method according to a comparative example will be described. FIG. 7 is a conceptual diagram showing the operation of the transport vehicle 200 that employs the turning control method according to the comparative example. The tractor 201 of the transport vehicle 200 travels following the first guide line TL1, and in the first region E1 on the upstream side of the second guide line TL2 in the first traveling direction D1, autonomously travels. to turn and transfer to the second guide line TL2. In this case, since there is an inner wheel difference between the towing vehicle 201 and the towed vehicle 202, the towed vehicle 202 needs to make a large turn inward in the vicinity of the intersection. In this case, the equipment EB needs to be installed at a large distance from the guide lines TL1 and TL2 so that the equipment EB on the inner peripheral side and the towed vehicle 202 do not come into contact with each other. In addition, the towed vehicle 202 must travel a long distance until the direction of the towed vehicle 202 becomes parallel to the second guide line TL2 (until the state shown by A in FIG. 7 is reached). For example, when loading and unloading at a place near the turning place (a place closer to the first guide line TL1 than the place indicated by A), the towed vehicle 202 stopped at an angle must be worked. Gone. Therefore, there is a problem that the automatic transfer equipment becomes difficult to use.

FIG. 8 is a conceptual diagram showing the operation of a transport vehicle 300 that employs a turning control method according to another comparative example. In this turn control method, a third guide line TL3 is provided for the tractor 301 to make a large turn in the second region E2 downstream of the second guide line in the first traveling direction D1. The towing vehicle 301 is controlled to follow the third guide line TL3 without autonomous travel. As a result, the towed vehicle 302 can reduce the influence of the inner wheel difference near the intersection and make a small turn. However, in the turning control method, it is necessary to lay a guide wire such as a magnetic tape in a complicated shape, and there is a problem that it takes a lot of time and effort when there are many turning places. Furthermore, when there are towed vehicles of a plurality of sizes, there is a problem that there is no optimal laying shape for each size.

On the other hand, in the turning control method according to the present embodiment, the towing vehicle 1 traveling in the first traveling direction D1 following the first guide line TL1 while towing the towed vehicle 2 turns. In a turning control method for transferring to a second guide line TL2 that intersects with the first guide line TL1, in a second area E2 on the downstream side of the second guide line TL2 in the first travel direction D1, the towing A turning step S50 is provided for turning the vehicle 1 by autonomous driving.

When the towing vehicle 1 turns in the second area E2 downstream of the second guide line TL2 in the first travel direction D1, the towing vehicle 1 makes a large turn. In this case, the towed vehicle 2 towed on the upstream side of the towed vehicle 1 in the first traveling direction D1 is less affected by the inner wheel difference from the towed vehicle 1. 2 (at least compared to the comparative example shown in FIG. 7), the direction can be changed in a small turn. As described above, the motion of the towed vehicle 2 during turning can be reduced to a small radius.

The turning control method detects the mark MK while the towing vehicle 1 is traveling following the first guiding line TL1, and then causes the towing vehicle 1 to travel a certain distance following the first guiding line TL1. A following travel step S10 is further provided, and the following travel step S10 is switched to a turning step S50 in a second area E2 downstream of the second guide line TL2 in the first traveling direction D1. In this way, the towing vehicle 1 is made to follow the first guide line TL1 for a certain distance instead of automatically running immediately after detecting the mark MK. As a result, using the first guide line TL1, the towing vehicle 1 can be made to reach the second region E2 on the downstream side in the first traveling direction D1 from the second guide line TL2. As a result, using the first guide line TL1, the towed vehicle 2 travels the distance to the second area E2 downstream of the second guide line TL2 in the first traveling direction D1. It can be changed according to the dimensions, and even if there are a plurality of towed vehicles 2 with different dimensions, switching to the turning step can be performed at an ideal position without changing the position of the mark MK.

In the turning control method, in the turning step S50, the connecting portion 12 between the towing vehicle 1 and the towed vehicle 2 forms a virtual point at which the distance from the first guide line TL1 is equal to the distance from the second guide line TL2. The towing vehicle 1 is turned so as to turn as the center of rotation CP. In this way, by causing the connecting portion 12 to turn around the center of rotation CP, the movement of the towed vehicle 2 can be made a small turn, and the center line of the towed vehicle 2 after turning and the center line of the towed vehicle 2 can be aligned with each other. 2 of the guide line TL2 can be minimized.

In the turning control method, at the start of the turning step S50, the towing vehicle 1 is rotated about the connecting portion 12 between the towing vehicle 1 and the towed vehicle 2 to change direction. The towing vehicle 1 can turn without moving the towed vehicle 2 . In this case, there is no need to consider the track of the towed vehicle 2 when the towing vehicle 1 changes direction, and the amount of movement of the towed vehicle 2 can be reduced. As a result, it is possible to simplify the contents of processing for autonomous travel, and to make the motion of the towed vehicle 2 in a small radius.

In the turning control method, a plurality of constant distance parameters (for example, distance L4) are stored, and the step switching point for switching from the following travel step S10 to the turning step S50 is changed based on the dimensional information of the towed vehicle 2. In this case, it is possible to switch to the turning step S50 at a timing according to the dimensions of the towed vehicle 2 .

The control device 20 crosses the first guide line TL1 by turning the towing vehicle 1 traveling in the first traveling direction D1 following the first guide line TL1 while towing the towed vehicle 2. A control device 20 for transferring to the second guide line TL2, which performs control to turn the towing vehicle 1 by autonomous travel in a region E2 on the downstream side of the second guide line TL2 in the first traveling direction D1. .

According to this control device 20, it is possible to obtain the same functions and effects as those of the turning control method described above.

The invention is not limited to the embodiments described above.

In the above-described embodiment, the mark MK is arranged at a position spaced forward from the second guide line TL2. However, the position of the mark MK may be adjusted to a position on the upstream side or the downstream side in the first traveling direction D1. The mark MK may be arranged in the second region E2. However, when the mark MK is arranged in the first area E1, the mark sensor 14 can detect the second guide line TL2, and the detection result can be used to confirm the current position or estimate the traveled distance. can be used effectively. Also, after the mark is detected, the size of the trajectories of the towing vehicle 1 and the towed vehicle 2 may be adjusted by varying the distance traveled following the first guide line TL1.

After detecting the mark MK, the control device 20 may cause the towing vehicle 1 to travel autonomously to the second region E2.

In the above-described embodiment, the control device 20 executes the turning step S50 in which the towing vehicle 1 turns by autonomous traveling in the second region E2. In the direction changing step S40 of the turning step S50, part of the vehicle body of the towing vehicle 1 has entered the first area E1. In this way, during the entire period of the turning step S50, the entire body of the towing vehicle 1 does not need to be present in the second region E2. It may enter the first area E1. For example, in the turning step S50, the processing was started from a state in which the entire vehicle body of the towing vehicle 1 exists in the second region E2, but part or the entire vehicle body of the towing vehicle 1 exists in the second region E2. Processing may start from a state. In this case, the autonomous travel is controlled so that the connecting portion 12 of the towing vehicle 1 exists in the second region E2 during at least a part of the period of the turning travel step S30.

Also, the intersection angle between the first guide line TL1 and the second guide line TL2 may not be 90°, and may be an inclined angle. Note that the mark MK and the intersection angle are associated with each other, and the control device 20 may grasp the intersection angle at the same time as detecting the mark MK.

DESCRIPTION OF SYMBOLS 1... Towing vehicle, 2... Towed vehicle, 12... Connection part, 20... Control device (swing control device), TL1... 1st guide line, TL2... 2nd guide line, MK... Mark.

Claims (4)

A turning control method in which a towed vehicle traveling in a traveling direction following a first guide line while towing a vehicle to be towed turns, thereby transferring to a second guide line that intersects the first guide line. hand,
A turning step of turning the towing vehicle by autonomous traveling in a region downstream of the second guide line in the traveling direction ,
After detecting the mark while the towing vehicle is traveling following the first guide line, a following travel step of causing the towing vehicle to travel a certain distance following the first guide line is further included. prepared,
switching from the following travel step to the turning step in a region downstream of the second guide line in the traveling direction;
A turning control method , wherein a plurality of parameters of the constant distance are stored, and a step switching point for switching from the following travel step to the turning step is changed based on the dimensional information of the towed vehicle . In the turning step, the connecting portion between the towing vehicle and the towed vehicle turns around a virtual point at which the distance from the first guide line and the distance from the second guide line are equal. 2. The turning control method according to claim 1 , further comprising turning the towing vehicle. 3. The turning control method according to claim 1 or 2 , wherein at the start of said turning step, said towing vehicle is rotated about a connecting portion between said towing vehicle and said towed vehicle to change direction. The turning control device moves to a second guide line that intersects the first guide line by turning the towing vehicle that travels in the traveling direction following the first guide line while towing the towed vehicle. hand,
controlling a turning step for turning the towing vehicle by autonomous travel in a region downstream of the second guide line in the direction of travel ;
After detecting a mark while the towing vehicle is traveling following the first guide line, control of a follow-up travel step in which the towing vehicle travels a certain distance following the first guide line. and
switching from the following travel step to the turning step in a region downstream of the second guide line in the traveling direction;
A turning control device that stores a plurality of parameters of the constant distance, and changes a step switching point for switching from the following travel step to the turning step based on the dimensional information of the towed vehicle .

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