Control system for work vehicles

The control system for work vehicles optimizes route calculation by generating tangent circles based on vehicle position and direction, reducing computational load and enhancing efficiency in autonomous driving.

JP2026109254APending Publication Date: 2026-07-01ISEKI & CO LTD

Patent Information

Authority / Receiving Office
JP · JP
Patent Type
Applications
Current Assignee / Owner
ISEKI & CO LTD
Filing Date
2024-12-19
Publication Date
2026-07-01

AI Technical Summary

Technical Problem

Conventional control systems for work vehicles, such as agricultural tractors, increase calculation load due to the need to consider multiple routes with forward and reverse movements, as they do not account for the vehicle's current position and direction relative to the work start point.

Method used

A control system that includes a vehicle body, positioning device, azimuth acquisition means, and a control unit to generate a work path by setting starting and entry circles tangent to specific vectors, reducing the number of candidate paths by considering turning radii and allowing autonomous driving.

Benefits of technology

This approach reduces computational load and improves efficiency by selecting the shortest path to the work start point, ensuring smooth and efficient movement while suppressing calculation overhead.

✦ Generated by Eureka AI based on patent content.

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Abstract

To provide a control system for work vehicles that can improve the efficiency of movement to the work start point while suppressing the computational load. [Solution] The system comprises a portable terminal device for inputting information about the work equipment to be attached, and a control unit that generates a work route including the work start point in the field and controls the vehicle body to perform work while autonomously driving along the generated work route. The control unit generates a starting circle which is a circle with a turning radius that is tangent to the azimuth vector acquired by the azimuth acquisition means and the self-position acquired by the positioning device, and an entry circle which is a circle with a turning radius that is tangent to the work route vector and the work start point. Based on the information about the work equipment, the control unit generates a plurality of candidate movement routes including the portion along the starting circle and the entry circle, and sets the route that is the shortest between the self-position and the work start point from the plurality of generated routes as the autonomous driving movement route.
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Description

Technical Field

[0001] The present invention relates to a control system for a work vehicle.

Background Art

[0002] Conventionally, in a work vehicle such as an agricultural tractor capable of autonomous driving, a plurality of routes are set by a circle tangent to a work start point, a circle tangent to the self-position, and a line or a circle tangent to both of these circles as a movement route to a work start point where the position and orientation are determined, and the shortest one is selected from them as an actual movement route. A control system for a work vehicle is known (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the conventional technology as described above, the route could be set by a unified algorithm regardless of the relationship between the vehicle's current position and direction and the position and direction of the work start point. However, since the route was calculated assuming that the moving vehicle only moves forward, while the time can be shortened by switching between forward and reverse, the number of candidates for the shortest possible route increases with the switching between forward and reverse, and there is a concern that the calculation load will increase.

[0005] The present invention has been made in view of the above, and an object thereof is to provide a control system for a work vehicle that can improve the efficiency of moving to a work start point while suppressing the calculation load.

Means for Solving the Problems

[0006] To solve the above-mentioned problems and achieve the objective, the control system for a work vehicle according to the embodiment comprises a vehicle body capable of traveling within a field, a positioning device for acquiring the vehicle body's own position, an azimuth angle acquisition means for acquiring the azimuth angle of the vehicle body, a portable terminal device for inputting information on the work equipment to be attached, and a control unit for generating a work path including the work start point within the field and controlling the vehicle body to perform work while autonomously traveling along the generated work path, wherein the control unit pre-determines the turning radius of the vehicle body when it moves within the field. The system is characterized by setting the following: generating a starting circle which is a circle with a turning radius that is tangent to the vector of the azimuth acquired by the azimuth acquisition means and the self-position acquired by the positioning device; generating an entry circle which is a circle with a turning radius that is tangent to the vector of the work path and the work start point; generating a plurality of candidate movement paths that include the portion along the starting circle and the entry circle based on the information of the work machine; and setting the path that is the shortest between the self-position and the work start point from the plurality of generated paths as the autonomous driving movement path. [Effects of the Invention]

[0007] According to the work vehicle of this embodiment, instead of comparing all possible shortest travel routes, the number of possible shortest travel routes can be reduced based on information about the work equipment. This allows for more efficient movement to the work starting point while suppressing the computational load. [Brief explanation of the drawing]

[0008] [Figure 1] Figure 1 is a schematic left side view showing a work vehicle according to an embodiment. [Figure 2] Figure 2 is a block diagram showing the control system for a work vehicle according to an embodiment. [Figure 3] Figure 3 is an explanatory diagram (part 1) of autonomous driving in a field. [Figure 4] Figure 4 is an explanatory diagram (part 2) of autonomous driving in a field. [Figure 5] Figure 5 is a flowchart (part 1) showing the process of setting the travel route. [Figure 6] Figure 6 is a flowchart (part 2) showing the process of setting the travel route. [Modes for carrying out the invention]

[0009] Hereinafter, embodiments of the control system for work vehicles disclosed in this application will be described in detail with reference to the attached drawings. However, this invention is not limited to the embodiments described below.

[0010] First, an overview of the work vehicle 1 according to the embodiment will be described with reference to Figure 1. Figure 1 is a schematic left side view showing the work vehicle 1 according to the embodiment. In the following description, a tractor will be used as an example of the work vehicle 1. Furthermore, the tractor 1, which is the work vehicle, is an agricultural tractor that performs farm work in the field while moving under its own power.

[0011] Furthermore, the tractor 1, which is a work vehicle, can perform predetermined tasks while being driven around the field with an operator (also called a worker) on board. In addition, it can perform predetermined tasks while autonomously driving around the field, controlled by a control system centered on the control unit 200 (see Figure 2), which will be described later.

[0012] In the following explanation, the forward and backward directions refer to the direction of travel when the tractor 1 is moving straight, with the front side of the direction of travel defined as "forward" and the rear side as "rear." The direction of travel of the tractor 1 is the direction from the driver's seat 8 (described later) towards the steering wheel 9 when the tractor 1 is moving straight.

[0013] Furthermore, the left-right direction is the direction perpendicular to the front-rear direction. In the following, left and right are defined with respect to the "front" side. That is, with the operator seated in the cockpit 8 facing forward, the left side is "left" and the right side is "right". The up-down direction is the vertical direction. The front-rear direction, left-right direction, and up-down direction are perpendicular to each other in three dimensions. Also, in the following explanation, the tractor 1 or the vehicle body 2 may be referred to as the "machine body".

[0014] As shown in Figure 1, the tractor 1 comprises a vehicle body 2 and an implement 6. The vehicle body 2 is capable of traveling within a field and is equipped with front wheels 3 and rear wheels 4. The front wheels 3 are a pair of steering wheels (steering wheels) provided on the left and right sides. The rear wheels 4 are a pair of drive wheels (drive wheels) provided on the left and right sides. The vehicle body 2 may also be equipped with a crawler system instead of wheels (at least one of the front wheels 3 and rear wheels 4). In this case, the crawler is the drive wheel.

[0015] The rotational power generated by the engine E, which is the drive source housed in the bonnet 5, is transmitted to the rear wheels 4, which are the drive wheels, after being appropriately reduced by the transmission 121 (see Figure 2) located in the power transmission case 12. The rear wheels 4 are driven by the rotational power transmitted from the engine E. The transmission 121 switches the rotational power transmitted from the engine E to one of several gears (for example, 1st to 8th gear).

[0016] The vehicle body 2 is configured to transmit power generated by the engine E and reduced by the transmission 121 to the front wheels 3 via the 4WD clutch. In this case, when the 4WD clutch transmits power, all four wheels, the front wheels 3 and the rear wheels 4, are driven by the power transmitted from the engine E. When the 4WD clutch disconnects the power transmission, only the rear wheels 4 are driven by the power transmitted from the engine E. Thus, the vehicle body 2 is configured to be switchable between two-wheel drive (2WD) and four-wheel drive (4WD).

[0017] A work implement 6 for use in the field is attached to the rear of the vehicle body 2, and a PTO (Power take-off) device 7 with a PTO shaft 71 that transmits power to drive the work implement 6 is provided. In the center of the vehicle body 2 is a driver's seat 8 where the operator sits when operating the tractor 1.

[0018] In front of the driver's seat 8, a steering wheel 9, which is a handle for steering the front wheels 3, is provided. The steering wheel 9 and a drive unit for driving the steering wheel, etc. constitute a steering device 122 (see FIG. 2). The steering wheel 9 is provided at the upper end of a handle post 10. Below the handle post 10 and near the feet of the operator when the operator is sitting on the driver's seat 8, various operation pedals 11 (an accelerator pedal, a brake pedal, a clutch pedal) are provided.

[0019] Also, at the rear of the traveling vehicle body 2, a lifting device 13 for raising and lowering the working machine 6 is provided. The lifting device 13 moves the working machine 6 to a non-working position by raising the working machine 6. Also, the lifting device 13 moves the working machine 6 to a ground working position by lowering the working machine 6. The lifting device 13 includes a hydraulic lifting cylinder 131, a lift arm 132, a lift rod 133, a lower link 134, and a top link 135.

[0020] When hydraulic oil is supplied to the lift arm 132, the lift arm 132 rotates around the axis AX to raise the working machine 6, and when the hydraulic oil is discharged from the lift arm 132, the lift arm 132 rotates around the axis AX to lower the working machine 6. A lift arm sensor for detecting the rotation angle of the lift arm 132 is provided at the base of the lift arm 132 (near the axis AX). The height of the working machine 6 is calculated based on the detection value of the lift arm sensor.

[0021] Also, the lift arm 132 is connected to the lower link 134 via the lift rod 133. Thus, the lifting device 13 connects the working machine 6 to the traveling vehicle body 2 so that the working machine 6 can be raised and lowered by the lower link 134 and the top link 135.

[0022] In the example shown in FIG. 1, the case where the working machine 6 is a rotary tiller is illustrated. The rotary tiller tills the field surface (soil) by rotating the tilling claws 61 by the power transmitted from the PTO shaft 71 of the PTO device 7.

[0023] Furthermore, the tractor 1 is equipped with a control unit 200 (see Figure 2). The control unit 200 controls the engine E and the travel speed of the vehicle body 2. The control unit 200 also controls the implement 6.

[0024] Furthermore, the tractor 1 is equipped with a positioning device 150. The positioning device 150 is mounted on the upper part of the vehicle body 2 and measures the position of the vehicle body 2 at predetermined intervals and acquires information (for example, latitude and longitude) of the vehicle body 2's own position P0 (see Figure 3). The positioning device 150 is, for example, a GNSS (Global Navigation Satellite System) and can perform positioning and timing by receiving radio waves from navigation satellites S orbiting overhead.

[0025] Furthermore, the tractor 1 allows the operator to set various tasks in a specific field by operating a portable terminal device 160. The portable terminal device 160 is, for example, a tablet device that can connect to a communication network such as the internet and can connect to a work management device via the communication network. In this case, the work management device is a system that is capable of so-called cloud computing. The portable terminal device 160 and the work management device are connected, for example, via a wireless LAN (Local Area Network).

[0026] The mobile terminal device 160 includes a storage unit, such as a hard disk, ROM (Read Only Memory), and RAM (Random Access Memory), and a display unit and operation unit, which are configured as a touch panel. Various keys and buttons may be provided separately as part of the operation unit. Furthermore, the mobile terminal device 160 may include a processing unit, such as a CPU (Central Processing Unit), to enable electronic control of each component, similar to the control unit 200 described later.

[0027] A work management device is a computer equipped with a processing unit such as a CPU, storage devices such as ROM (Read Only Memory), RAM (Random Access Memory), and HDD (Hard Disk Drive), and input / output devices.

[0028] Furthermore, the tractor 1 is equipped with an azimuth acquisition means 170 (see Figure 2). The azimuth acquisition means 170 acquires the azimuth of the vehicle body. The azimuth acquisition means 170 is, for example, an azimuth sensor. Hereinafter, the azimuth acquisition means 170 will be referred to as the azimuth sensor.

[0029] The azimuth sensor 170 detects, for example, the absolute azimuth of the direction of travel of the vehicle body 2 (for example, with "north" as 0° (360°), "east" as 90°, "south" as 180°, and "west" as 270°). The azimuth sensor 170 detects the absolute azimuth at regular intervals and transmits the detected absolute azimuth to the control unit 200 or the like. In addition to the azimuth sensor, the azimuth acquisition means 170 may also include, for example, a geomagnetic sensor.

[0030] Next, with reference to Figure 2, the control system 100 of the work vehicle according to the embodiment, that is, the control system of the work vehicle (tractor) 1 centered on the control unit 200, will be described. Figure 2 is a block diagram of the control system 100 of the work vehicle according to the embodiment. As shown in Figure 2, the control unit 200 includes an engine ECU (Electronic Control Unit) 201, a driving system ECU 202, and a work implement lifting system ECU 203.

[0031] The engine ECU 201 controls the rotational speed of the engine E. The drive system ECU 202 controls the travel speed of the vehicle body 2 (see Figure 1) by controlling the rotation of the drive wheels (rear wheels 4). The work equipment lifting system ECU 203 controls the lifting device 13 to drive the work equipment 6 up and down.

[0032] The control unit 200 is capable of controlling each part by electronic control and includes a processing unit having a CPU (Central Processing Unit), as well as a storage unit consisting of, for example, a hard disk, ROM (Read Only Memory), RAM (Random Access Memory), etc., which stores necessary data such as various programs and the planned travel route (hereinafter referred to as the work route) R1 of the vehicle body 2, which is set in advance for each field.

[0033] As shown in Figure 2, the control unit 200 is connected to a positioning device (GNSS) 150, an azimuth sensor 170, an engine speed sensor 110, a vehicle speed sensor 111, a gear shift sensor 112, a steering angle sensor 113, and the like. The control unit 200 is also connected to the engine E, a transmission 121, a steering device 122, a lifting device 13, and the like.

[0034] The engine speed sensor 110 detects the rotational speed of the engine E. The vehicle speed sensor 111 detects the driving speed (vehicle speed) of the vehicle body 2 (see Figure 1). The gear shift sensor 112 detects which of the multiple gears the transmission 121 is in. The steering angle sensor 113 detects the steering angle of the front wheels 3 (see Figure 1), which are the steering wheels.

[0035] The control unit 200 receives the following inputs: position information (self-position) of the vehicle body 2 in a field, etc., from the positioning device 150; engine speed from the engine speed sensor 110; vehicle speed from the vehicle speed sensor 111; current gear from the gear shift sensor 112; and steering angle of the front wheels 3 from the steering angle sensor 113. When the vehicle body 2 is autonomously driven, the control unit 200 steers the steering wheel 9 (see Figure 1) by controlling the steering cylinder connected to the steering wheel 9 while feeding back the steering angle of the front wheels 3 using the detected value from the steering angle sensor 113, as described above.

[0036] In the control unit 200, the engine ECU 101 is connected to the engine E, the drive system ECU 102 is connected to the transmission 121 and steering system 122, and the work equipment lifting system ECU 103 is connected to the lifting device 13. The work equipment lifting system ECU 103 raises and lowers the work equipment via the lifting device 13.

[0037] Furthermore, when the vehicle body 2 is to move autonomously, the control unit 200 pre-determines a work path R1 (see Figure 3) for each field according to the work performed by the implement 6, digitizes the data, and stores it in the memory unit. Based on the measurement results of the positioning device 150, the control unit 200 controls the engine E, transmission 121, steering device 122, lifting device 13, etc., so that the vehicle moves along the work path R1 stored in the memory unit and performs the work. The work path R1 is set according to the shape and size of the field, the width, length and number of ridges formed in the field, and the type of crop. The control unit 200 also pre-sets the turning radius when the tractor 1 (vehicle body 2) moves within the field.

[0038] Furthermore, as described above, the control unit 200 is wirelessly connected to, for example, a portable terminal device (tablet terminal) 160 that can be carried by the operator. The control unit 200 controls each part of the tractor 1 based on instruction signals from the portable terminal device 160 operated by the operator. The control unit 200 may also have a database of machine information for the tractor 1 and be configured to allow the exchange of information such as the model number from the portable terminal device 160 or the like.

[0039] Next, the autonomous driving of the work vehicle (tractor) 1 within field F1 will be explained with reference to Figures 3 to 6. Figures 3 and 4 are explanatory diagrams of autonomous driving within field F1, and are schematic diagrams viewed from above the field. Figure 3 shows the case where the distance between the starting circle C1, which is the turning radius circle when the vehicle body 2 starts moving, and the entry circle C2, which is the turning radius circle when entering the work path R1, is a predetermined distance (for example, 10 m) or more, while Figure 4 shows the case where the distance between the starting circle C1 and the entry circle C2 is less than the predetermined distance.

[0040] Figures 5 and 6 are flowcharts showing the process for setting the travel path R2. Figure 6 shows the process for setting a travel path R2 that does not deviate from the deviation-prohibition area A2.

[0041] For example, in the case of tilling work performed by tractor 1 while autonomously driving, the control unit 200 (see Figure 2) generates a work path R1 in which appropriate turning positions and tilling depths are defined, based on information such as the overall length, overall width, and tread of tractor 1, the capacity of implement 6 (see Figure 1), and the shape and area of ​​field F1.

[0042] Furthermore, worker H can also remotely send instructions to tractor 1 by operating a portable terminal device 160 from a ridge F2 or other location.

[0043] As shown in Figures 3 and 4, tractor 1 enters field F1 from the entrance / exit along the work path R1 and automatically performs tilling work while appropriately turning within the work area A1 set up within field F1. Depending on the program, tractor 1 can also be controlled to exit field F1 from the entrance / exit after tilling work and stop at a predetermined location.

[0044] Tractor 1 (vehicle body 2) performs ground work while circling within a predetermined area inside the ridge F2, i.e., the area inside the edge of field F1, which is designated as the headland area. In the work area A1 inside the headland area, tractor 1 performs ground (plowing) work along the work path R1, alternating between moving straight and turning, from a predetermined work start point P1 to a work end point P2.

[0045] Furthermore, in this embodiment, as shown in Figures 3 and 4, the movement path R2 of the tractor 1 (vehicle body 2) is set so that when the tractor 1 starts work, it moves along an appropriate path to the work start point P1.

[0046] In this case, as shown in Figures 3 and 4, the control unit 200 sets a starting circle C1 that is tangent to the azimuth vector V1 acquired by the azimuth acquisition means 170 and the self-position P0 acquired by the positioning device 150, and sets an entry circle C2 that is tangent to the vector V2 of the work path R1 and the work start point P1. The control unit 200 also sets a tangent L1 to the starting circle C1 and entry circle C2 of the two turning radii. Based on the starting circle C1 and entry circle C2 of the two turning radii and the tangent L1, the control unit 200 generates multiple paths.

[0047] Here, the starting circle C1, which is tangent to the azimuth vector V1 and the self-position P0, has two forms: a leftward starting circle C1L that is tangent to the azimuth vector V1 to the left, and a rightward starting circle C1R that is tangent to the azimuth vector V1 to the right. Also, the entry circle C2, which is tangent to the work path R1 vector V2 and the work start point P1, has two forms: a leftward entry circle C2L that is tangent to the work path R1 vector V2 to the left, and a rightward entry circle C2R in which the traveling vehicle body 2 is tangent to the work path R1 to the right.

[0048] When moving along path R2 only in the forward direction, the Dubins curve allows for a maximum of six possible paths, including a leftward starting circle C1L or a rightward starting circle C1R, and a leftward entry circle C2L or a rightward entry circle C2R, with the shortest path being the shortest between the two points.

[0049] If the movement path R2 includes both forward and reverse movement, as shown in Figure 4, the shortest path can also be the one along the first intermediate circle C12 tangent to the starting circle C1 and the second intermediate circle C22 tangent to the entry circle C2. In total, the Reeds-Shepp curve can produce up to 48 possible shortest paths. For example, the first intermediate circle C12 is tangent to the leftward starting circle C1L and the second intermediate circle C22, and the second intermediate circle C22 is defined by the circle tangent to the first intermediate circle C12 and the rightward entry circle C2R. After starting to move by turning left along the leftward starting circle C1L, the movement switches to turning right along the first intermediate circle C12 from the point of contact with the first intermediate circle C12, switches to reverse from the point of contact with the second intermediate circle C22 and moves clockwise along the second intermediate circle C22, and then moves counterclockwise along the rightward entry circle C2R from the point of contact with the rightward entry circle C2R to reach the work start point. The work can begin by switching to forward motion from the starting point.

[0050] The control unit 200 calculates candidate shortest paths, including reverse movement, and sets the shortest path from its own position P0 to the work start point P1 as the movement path R2. The control unit 200 also displays the set movement path R2 on the display screen of the portable terminal device 160.

[0051] When setting a movement path R2, the control unit 200 generates multiple paths based on the starting circle C1, entry circle C2, first intermediate circle C12, second intermediate circle C22 and tangent line L1, depending on the situation, as shown in Figure 5 (step S101).

[0052] Next, the control unit 200 selects the shortest path from multiple paths between its own position P0 and the work start point P1 (step S102). Then, the control unit 200 sets the selected shortest path as the movement path R2 (step S103) and terminates the process.

[0053] With this configuration, during autonomous driving of the tractor 1, a path is generated by smoothly connecting the self-position P0 of the vehicle body 2 with the work start point P1. Since the tractor can move along the shortest path (movement path) R2 among the generated paths, the efficiency of movement to the work start point P1 can be improved, and work can be started smoothly. As a result, work efficiency can be improved.

[0054] Furthermore, as shown in Figure 3, the control unit 200 sets a deviation prevention area A2 outside the work area A1 to prevent the vehicle body 2 from deviating. Therefore, the vehicle body 2 can travel (move) within the deviation prevention area A2. If, among multiple paths, the shortest path from its own position P0 to the work start point P1 includes a portion of the path that deviates from the deviation prevention area A2, the control unit 200 excludes the path that includes the portion of the path. In other words, if a path contains a component (partial path) that deviates from the deviation prevention area A2, that path is excluded.

[0055] The control unit 200 then sets the shortest path from its own position P0 to the work start point P1 as the movement path R2, excluding the path containing the deviation component from the remaining paths. In this case, even if the shortest path contains the deviation component, such a path is not set as the movement path R2. Furthermore, if the next shortest path contains the deviation component, it is also not set as the movement path R2. This process is repeated until the shortest path does not contain the deviation component. In addition, if all paths contain the deviation component, the control unit 200 does not set the movement path R2 and, for example, displays on the display screen of the mobile terminal device 160 that the movement path R2 cannot be set.

[0056] When the control unit 200 sets a movement path R2 that does not deviate from the deviation-prohibition area A2, it generates multiple paths based on the movement start circle C1, entry circle C2, first intermediate circle C12, second intermediate circle C22 and tangent line L1, depending on the situation, as shown in Figure 6 (step S201).

[0057] Next, the control unit 200 selects the shortest path from multiple paths between its own position P0 and the work start point P1 (step S202). Then, the control unit 200 determines whether the shortest path includes a portion of the path that deviates from the deviation prohibition area A2 (step S203).

[0058] If the control unit 200 determines that the shortest path includes a portion of the path that deviates from the deviation-prohibited area A2 (step S203: Yes), it selects the shortest path again from the paths that do not include the deviating portion, sets the newly selected shortest path as the travel path R2 (step S204), and terminates the process.

[0059] Furthermore, if the control unit 200 determines that the shortest path does not include a portion of the path that deviates from the deviation-prohibited area A2 (step S203: No), the control unit 200 sets the selected shortest path as the travel path R2 (step S103) and terminates the process. Note that in the processes of steps S203 and S204, the control unit 200 may also determine whether the newly selected shortest path includes a portion of the path that deviates from the deviation-prohibited area A2, and may repeat this process until it determines that the path does not include a portion of the path that deviates from the deviation-prohibited area A2.

[0060] With this configuration, movement can be made along the shortest path (travel path) R2 while preventing deviation from field F1 and contact with ridge F2, thus improving the efficiency of movement to the work starting point P1 while ensuring safety.

[0061] The control unit 200, if the distance from its own position P0 to the work start point P1 is greater than a predetermined distance (for example, 6 times the turning radius), excludes paths that do not contain straight lines from the candidates and performs calculations. There are up to 48 Reeds-Shepp curves, but by excluding paths that do not contain straight lines, the number of candidates is reduced to 30, thus reducing the computational load.

[0062] Furthermore, if the control unit 200 obtains information that automatic reverse movement is impossible for the connected work machine from the communication standard connecting to the work machine 6 or from the portable terminal device 160, it excludes paths that include reverse movement from the candidates and performs calculations. If paths that include reverse movement are excluded from the candidates, the number of shortest path candidates becomes a maximum of 6 using the Dubins curve, and if the distance from the self-position P0 to the work start point P1 is greater than or equal to a predetermined distance (for example, 6 times the turning radius), the number becomes a maximum of 4, thereby reducing the computational load. If information that automatic reverse movement is impossible is not obtained and the distance from the self-position P0 to the work start point P1 is less than or equal to a predetermined distance, up to 48 candidate paths are generated, the lengths of each path are compared, and the shortest path is set as the movement path R2.

[0063] By excluding routes that involve reversing from the options, the vehicle can be driven autonomously even when vehicle control during reverse movement is difficult, such as when a towed trailer-type work machine is attached.

[0064] According to this control system 100 for work vehicles, during autonomous driving, the system smoothly connects the vehicle's own position P0 with the work start point P1 to generate a traversable path. Since the vehicle can move along the shortest path (travel path) R2 among the generated paths, the efficiency of movement to the work start point P1 can be improved, and work can be started smoothly. This improves work efficiency.

[0065] Further effects and modifications can be readily derived by those skilled in the art. Therefore, broader aspects of the present invention are not limited to the specific details and representative embodiments expressed and described above. Accordingly, various modifications are possible without departing from the spirit or scope of the overall concept of the invention as defined by the appended claims and their equivalents. [Explanation of Symbols]

[0066] 1. Work vehicle (tractor) 2. Running vehicle 6. Work equipment 100 Control systems for work vehicles 150 Positioning devices (GNSS) 160 Mobile devices (tablet devices) 170. Azimuth acquisition method (azimuth sensor) 200 Control Unit A1 work area A2 No deviation area C1 Starting Circle C2 approach circle E-engine F1 field P0 Self-position P1 Work starting point P2 End of work point R1 Work Route R2 Travel Path V1 Vector V2 Vector

Claims

1. A vehicle capable of traveling within a field, A positioning device that acquires the self-position of the vehicle body, A means for acquiring the azimuth angle of the vehicle body, A portable terminal device for inputting information about the work equipment to be attached, The system includes a control unit that generates a work path including the starting point of work within the field, and controls the vehicle body to perform work while autonomously driving along the generated work path, The control unit, The turning radius of the vehicle body when it moves within the field is set in advance. The system generates a starting circle which is a circle with a turning radius that is tangent to the vector of the azimuth acquired by the azimuth acquisition means and the self-position acquired by the positioning device, and an entry circle which is a circle with a turning radius that is tangent to the vector of the work path and the work start point. Multiple candidate movement paths, including the portion along the starting circle and the entry circle, are generated based on the information of the work machine. A control system for a work vehicle, characterized by setting the shortest route from the vehicle's own position to the work start point among the multiple routes generated as the autonomous driving route.

2. The control unit, If the information on the aforementioned work machine includes information that automatic reverse movement is not possible, candidate movement paths that do not include reverse movement are generated. The control system for a work vehicle according to claim 1, characterized in that if the information of the work machine does not include information that automatic reverse movement is not possible, it generates candidate movement paths that include reverse movement.

3. The control unit, when the distance between its own position and the work start point is greater than or equal to a predetermined distance, compares the lengths of the paths by excluding paths that do not include straight lines from among the candidates for the shortest possible path, and sets the shortest path as the movement path, as described in claim 2.