Automatic travel method, automatic travel program, and automatic travel system

Abstract

To provide an automatic travel method, an automatic travel program, and an automatic travel system with which a work vehicle can automatically travel accurately along a target path including a straight path and a turning path.SOLUTION: In an automatic travel system 1, a setting processing part 112 sets a target position to a predetermined position separated from a current position in a travel direction side by a predetermined distance on the basis of an angle formed by a first path in which the work vehicle 10 is traveling and a second path continuing to the first path and a distance from the current position of the work vehicle 10 to an end position of the first path. A travel processing part 111 causes the work vehicle 10 to travel so as to follow the target position.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a technique for automatically driving a work vehicle along a target route. [Background technology]

[0002] Conventionally, there is known a system that automatically drives a work vehicle along a predetermined target route in a farm field. For example, the work vehicle automatically drives along a straight route and a turning route included in the target route by performing steering control so as to follow a target position (travel target position) that is set at a predetermined position a predetermined distance in the traveling direction from the current position (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-078440 Summary of the Invention [Problem to be solved by the invention]

[0004] In conventional technology, for example, when a work vehicle moves from a straight path to a turning path, a target position is set on an extension of the straight path, and when the work vehicle reaches the end position of the straight path (the start position of the turning path), the target position is changed to the turning path, causing the work vehicle to turn. This causes the target position to suddenly switch from a position on an extension of the straight path to a position on the turning path, resulting in a problem of increased steering effort and unstable behavior of the work vehicle. On the other hand, a method can be considered in which the target position is changed to the turning path before the work vehicle reaches the end position of the straight path in order to reduce the steering effort, thereby switching the work vehicle to turning early. However, this method results in the work vehicle traveling further inward than the original target path (turning path), resulting in a problem of reduced work accuracy during turning.

[0005] An object of the present invention is to provide an automatic driving method, an automatic driving program, and an automatic driving system that are capable of automatically driving a work vehicle with high accuracy along a target path including a straight path and a turning path. [Means for solving the problem]

[0006] An automated driving method according to the present invention is an automated driving method for automatically driving a work vehicle along a target route including a straight route and a turning route. The automated driving method sets a target position at a predetermined position a predetermined distance in the traveling direction from the current position of the work vehicle based on an angle between a first route on which the work vehicle is traveling and a second route that follows the first route, and a distance from the current position of the work vehicle to an end position of the first route, and drives the work vehicle to follow the target position.

[0007] An automated driving program according to the present invention is an automated driving program for automatically driving a work vehicle along a target route including a straight route and a turning route. The automated driving program causes one or more processors to execute the following steps: set a target position at a predetermined position a predetermined distance in the traveling direction from the current position of the work vehicle based on an angle between a first route on which the work vehicle is traveling and a second route that follows the first route, and a distance from the current position of the work vehicle to an end position of the first route; and drive the work vehicle to follow the target position.

[0008] The automated driving system according to the present invention is an automated driving system that automatically drives a work vehicle along a target route including a straight route and a turning route. The automated driving system includes a setting processing unit and a driving processing unit. The setting processing unit sets a target position at a predetermined position a predetermined distance from the current position in the direction of travel based on the angle between a first route on which the work vehicle is traveling and a second route that follows the first route, and the distance from the current position of the work vehicle to the end position of the first route. The driving processing unit drives the work vehicle to follow the target position. [Effects of the Invention]

[0009] According to the present invention, it is possible to provide an automatic driving method, an automatic driving program, and an automatic driving system that are capable of automatically driving a work vehicle with high accuracy along a target route including a straight route and a turning route. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a block diagram showing the configuration of an automatic driving system according to an embodiment of the present invention. [Figure 2] FIG. 2 is an external view showing the configuration of a work vehicle according to an embodiment of the present invention. [Figure 3A] FIG. 3A is a diagram showing an example of a traveling method of a work vehicle according to an embodiment of the present invention. [Figure 3B] FIG. 3B is a diagram showing an example of a traveling method of the work vehicle according to the embodiment of the present invention. [Figure 4] FIG. 4 is a diagram showing an example of a method for registering a farm field according to an embodiment of the present invention. [Figure 5] FIG. 5 is a diagram showing an example of a method for registering a farm field according to an embodiment of the present invention. [Figure 6] FIG. 6 is a diagram showing an example of a menu screen displayed on the operation terminal according to the embodiment of the present invention. [Figure 7] FIG. 7 is a diagram showing an example of a method for setting the first reference line and the second reference line according to the embodiment of the present invention. [Figure 8A] FIG. 8A is a diagram showing an example of a method for converting a curve included in a second reference line into a straight line according to an embodiment of the present invention. [Figure 8B] FIG. 8B is a diagram showing an example of a method for converting a curve included in the second reference line into a straight line according to the embodiment of the present invention. [Figure 8C] FIG. 8C is a diagram showing an example of a method for converting a curve included in the second reference line into a straight line according to an embodiment of the present invention. [Figure 9] FIG. 9 is a diagram showing an example of a method for generating a target route according to an embodiment of the present invention. [Figure 10]FIG. 10 is a diagram showing an example of a traveling method of a work vehicle according to an embodiment of the present invention. [Figure 11A] FIG. 11A is a diagram showing an example of a method for setting a target position according to an embodiment of the present invention. [Figure 11B] FIG. 11B is a diagram showing an example of a method for setting a target position according to an embodiment of the present invention. [Figure 12] FIG. 12 is a flowchart showing an example of the procedure of a route generation process executed by the automated driving system according to the embodiment of the present invention. [Figure 13] FIG. 13 is a diagram showing another example of a traveling method for a work vehicle according to an embodiment of the present invention. [Figure 14] FIG. 14 is a diagram showing another example of a traveling method for a work vehicle according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0011] The following embodiment is an example of the present invention and does not limit the technical scope of the present invention.

[0012] As shown in Fig. 1, an automated driving system 1 according to an embodiment of the present invention includes a work vehicle 10 and an operation terminal 20. The work vehicle 10 and the operation terminal 20 can communicate with each other via a communication network N1. For example, the work vehicle 10 and the operation terminal 20 can communicate with each other via a mobile phone network, a packet network, or a wireless LAN. The automated driving system 1 is an example of an automated driving system according to the present invention.

[0013] In this embodiment, the work vehicle 10 will be described as a tractor. In other embodiments, the work vehicle 10 may be a combine harvester, rice transplanter, construction machinery, snowplow, or the like. The work vehicle 10 is configured to be able to automatically travel within a field F (see FIG. 4) along a predetermined target route.

[0014] For example, the worker (operator) registers the field F to be worked on and sets a target route for the work vehicle 10 to automatically travel through the field F. The work vehicle 10 automatically travels through the field F according to a predetermined target route based on position information of the current position of the work vehicle 10 acquired by the positioning unit 16. Specifically, the work vehicle 10 sets a target position (also called a travel target position or forward gaze point) at a predetermined position a predetermined distance in the direction of travel from the current position, and performs steering control to follow the target position, thereby automatically traveling along the target route. The work vehicle 10 also performs predetermined work while automatically traveling through the field F.

[0015] The operation terminal 20 is a portable terminal that can remotely operate the work vehicle 10, and is configured, for example, as a tablet terminal, a notebook personal computer, or a smartphone. The worker can perform setting operations for various setting items on the operation terminal 20. For example, the worker operates the operation terminal 20 to register a field F or set a target route for the registered field F. The operation terminal 20 can also display information such as the work status and driving status of the work vehicle 10 while it is traveling automatically, allowing the worker to grasp the work status and driving status on the operation terminal 20.

[0016] In the prior art, for example, when a work vehicle 10 moves from a straight path to a turning path, a target position is set on an extension of the straight path, and when the work vehicle 10 reaches the end position of the straight path (the start position of the turning path), the target position is changed to the turning path, causing the work vehicle 10 to turn. This causes the target position to suddenly switch from a position on an extension of the straight path to a position on the turning path, resulting in a problem of increased steering amount and unstable behavior of the work vehicle 10. On the other hand, a method can be considered in which the work vehicle 10 switches to turning early by changing the target position to the turning path before the work vehicle 10 reaches the end position of the straight path in order to reduce the steering amount. However, this method results in the work vehicle 10 traveling inside the original target path (turning path), resulting in a problem of reduced work accuracy during turning. In contrast, the automated driving system 1 according to this embodiment has a configuration that enables the work vehicle 10 to automatically travel accurately along a target path that includes a straight path and a turning path, as described below.

[0017] [Work vehicle 10] 1 and 2, the work vehicle 10 includes a vehicle control device 11, a memory unit 12, a traveling device 13, a work implement 14, a communication unit 15, a positioning unit 16, etc. The vehicle control device 11 is electrically connected to the memory unit 12, the traveling device 13, the work implement 14, and the positioning unit 16, etc. Note that the vehicle control device 11 and the positioning unit 16 may be capable of wireless communication.

[0018] The communication unit 15 is a communication interface that connects the work vehicle 10 to the communication network N1 by wire or wirelessly and performs data communication with external devices (such as the operation terminal 20) via the communication network N1 in accordance with a predetermined communication protocol.

[0019] The storage unit 12 is a non-volatile storage unit such as an HDD (Hard Disk Drive), SSD (Solid State Drive), or flash memory that stores various types of information. The storage unit 12 stores control programs such as an automatic driving program for causing the vehicle control device 11 to execute the automatic driving process (FIG. 12) described below. For example, the automatic driving program is non-temporarily recorded on a computer-readable recording medium such as a CD or DVD, and is read by a predetermined reading device (not shown) and stored in the storage unit 12. The automatic driving program may be downloaded from a server (not shown) to the work vehicle 10 via the communication network N1 and stored in the storage unit 12. The storage unit 12 also stores data such as a target route generated in the operation terminal 20.

[0020] The traveling device 13 is a drive unit that causes the work vehicle 10 to travel. As shown in Fig. 2, the traveling device 13 is equipped with an engine 131, front wheels 132, rear wheels 133, a transmission 134, a front axle 135, a rear axle 136, a handlebar 137, etc. The front wheels 132 and rear wheels 133 are provided on the left and right sides of the work vehicle 10, respectively. The traveling device 13 is not limited to a wheel type equipped with front wheels 132 and rear wheels 133, but may also be a crawler type equipped with crawlers provided on the left and right sides of the work vehicle 10.

[0021] The engine 131 is a drive source such as a diesel engine or a gasoline engine that runs on fuel supplied to a fuel tank (not shown). The traveling device 13 may be equipped with an electric motor as a drive source in addition to or instead of the engine 131. A generator (not shown) is connected to the engine 131, and power is supplied from the generator to the vehicle control device 11, positioning unit 16, and other electrical components provided on the work vehicle 10, as well as to a battery. The battery is charged with power supplied from the generator. The vehicle control device 11, positioning unit 16, and other electrical components provided on the work vehicle 10 can be driven by power supplied from the battery even after the engine 131 is stopped.

[0022] The driving force of the engine 131 is transmitted to the front wheels 132 via the transmission 134 and the front axle 135, and to the rear wheels 133 via the transmission 134 and the rear axle 136. The driving force of the engine 131 is also transmitted to the work implement 14 via a PTO shaft (not shown). When the work vehicle 10 performs autonomous driving, the traveling device 13 performs traveling operations in accordance with commands from the vehicle control device 11. The traveling device 13 also decelerates or stops the work vehicle 10 in accordance with commands from the vehicle control device 11.

[0023] The work implement 14 is, for example, a cultivator, a brush cutter, a plow, a fertilizer applicator, a sprayer (chemical applicator), a tiller, or a seed sower, and is detachable from the work vehicle 10. This allows the work vehicle 10 to perform various tasks using each of the work implements 14. FIG. 2 shows a case where the work implement 14 is a cultivator. For example, the work implement 14 is attached to the rear of the work vehicle 10. The work vehicle 10 performs tilling work by traveling within a field F with the work implement 14 attached to the rear.

[0024] The work implement 14 may be supported in the work vehicle 10 by a lifting mechanism (not shown) so that it can be raised and lowered. The vehicle control device 11 is able to raise and lower the work implement 14 by controlling the lifting mechanism. For example, the vehicle control device 11 lowers the work implement 14 when the work vehicle 10 travels straight forward in the field F, and raises the work implement 14 when the work vehicle 10 travels straight backward in the field F or when turning. Furthermore, when the work vehicle 10 performs work on a turning path, the vehicle control device 11 lowers the work implement 14 when the work vehicle 10 turns on the turning path. Furthermore, when the vehicle control device 11 acquires an instruction to stop work, it outputs a work stop command to the work implement 14. For example, when the operator performs a stop instruction operation on the operation terminal 20, the vehicle control device 11 acquires the stop instruction from the operation terminal 20. When the vehicle control device 11 acquires the instruction to stop work, it stops driving the PTO shaft to stop the work of the work implement 14.

[0025] The handle 137 is an operating unit that is operated by the worker or the vehicle control device 11. For example, in the traveling device 13, in response to operation of the handle 137 by the vehicle control device 11, the angle of the front wheels 132 is changed by a hydraulic power steering mechanism (not shown) or the like, and the traveling direction of the work vehicle 10 is changed.

[0026] In addition to the handlebars 137, the traveling device 13 is also equipped with a shift lever, accelerator, brake, etc. (not shown) that are operated by the vehicle control device 11. In the traveling device 13, the gear of the transmission 134 is switched to a forward gear, a reverse gear, etc. in response to operation of the shift lever by the vehicle control device 11, and the traveling mode of the work vehicle 10 is switched to forward, reverse, etc. The vehicle control device 11 also operates the accelerator to control the rotation speed of the engine 131. The vehicle control device 11 also operates the brake to brake the rotation of the front wheels 132 and rear wheels 133 using an electromagnetic brake.

[0027] The positioning unit 16 is a communication device including a positioning control unit 161, a memory unit 162, a communication unit 163, and a positioning antenna 164 (see FIG. 1). For example, as shown in FIG. 2, the positioning unit 16 is provided on top of the cabin 138 in which the worker rides. The installation location of the positioning unit 16 is not limited to the cabin 138. The positioning control unit 161, the memory unit 162, the communication unit 163, and the positioning antenna 164 of the positioning unit 16 may be disposed in different locations in the work vehicle 10. As described above, the battery is connected to the positioning unit 16, and the positioning unit 16 can operate even when the engine 131 is stopped. The positioning unit 16 may be substituted by, for example, a mobile phone terminal, a smartphone, a tablet terminal, or a quantum compass.

[0028] The positioning control unit 161 is a computer system including one or more processors and storage memories such as nonvolatile memory and RAM. The storage unit 162 is a nonvolatile memory or the like that stores data such as a program for causing the positioning control unit 161 to execute the positioning process, positioning information, and movement information. For example, the program is non-temporarily recorded on a computer-readable recording medium such as a CD or DVD, and is read by a predetermined reading device (not shown) and stored in the storage unit 162. Note that the program may be downloaded to the positioning unit 16 from a server (not shown) via the communication network N1 and stored in the storage unit 162.

[0029] The communication unit 163 is a communication interface that connects the positioning unit 16 to the communication network N1 via a wired or wireless connection and performs data communication in accordance with a predetermined communication protocol with external devices such as a base station server via the communication network N1.

[0030] The positioning antenna 164 is an antenna that receives radio waves (GNSS signals) transmitted from satellites.

[0031] The positioning control unit 161 calculates the current position of the work vehicle 10 based on the GNSS signals received by the positioning antenna 164 from satellites. For example, when the work vehicle 10 is autonomously traveling within a field F, the positioning antenna 164 receives radio waves (such as transmission time and orbit information) transmitted from each of a plurality of satellites. The positioning control unit 161 calculates the distance between the positioning antenna 164 and each satellite, and calculates the current position (latitude and longitude) of the work vehicle 10 based on the calculated distance. The positioning control unit 161 may also perform positioning using a real-time kinematic method (RTK-GNSS positioning method (RTK method)), which calculates the current position of the work vehicle 10 using correction information corresponding to a base station (reference station) close to the work vehicle 10. In this way, the work vehicle 10 performs autonomous traveling using positioning information obtained by the RTK method. The current position of the work vehicle 10 may be the same as the determined position (for example, the position of the positioning antenna 164), or may be displaced from the determined position. The positioning control unit 161 may calculate (measure) the current position of the work vehicle 10 using a quantum compass.

[0032] The vehicle control device 11 has control devices such as a CPU, ROM, and RAM. The CPU is a processor that executes various types of arithmetic processing. The ROM is a non-volatile storage unit in which control programs such as a BIOS and an OS that cause the CPU to execute various types of arithmetic processing are stored in advance. The RAM is a volatile or non-volatile storage unit that stores various types of information and is used as temporary storage memory for the various types of processing executed by the CPU. The vehicle control device 11 controls the work vehicle 10 by having the CPU execute various control programs that are stored in advance in the ROM or the storage unit 12.

[0033] Specifically, as shown in Fig. 1, the vehicle control device 11 includes various processing units such as a driving processing unit 111, a setting processing unit 112, and a vehicle speed control processing unit 113. The vehicle control device 11 functions as the various processing units by executing various processes in accordance with the automatic driving program using the CPU. Some or all of the processing units may be configured with electronic circuits. The automatic driving program may be a program for causing multiple processors to function as the processing units.

[0034] The driving processing unit 111 controls the driving of the work vehicle 10. For example, when the driving mode of the work vehicle 10 is manual driving (manual driving mode), the work vehicle 10 can be manually driven based on the operation (manual steering) of the worker. For example, the driving processing unit 111 acquires operation information corresponding to driving operations such as steering, gear shifting, driving direction switching, and braking by the worker, and causes the driving device 13 to perform driving operations based on the operation information. For example, when registering a field to be worked on, the worker gets on the work vehicle 10 and manually drives (teaching driving) the outer periphery of the work field within a predetermined area. Note that while the worker is teaching driving the work vehicle 10, the worker may lower the work implement 14 to perform a predetermined task (for example, tillage work).

[0035] Furthermore, when the driving mode of the work vehicle 10 is automatic driving (automatic driving mode), the driving processing unit 111 causes the work vehicle 10 to automatically drive based on position information (positioning information) indicating the current position of the work vehicle 10 measured by the positioning unit 16. For example, when the work vehicle 10 satisfies the conditions for starting automatic driving and the driving processing unit 111 receives a work start instruction (automatic driving start instruction) from the worker, the driving processing unit 111 causes the work vehicle 10 to automatically drive based on the positioning information. Furthermore, the driving processing unit 111 causes the work vehicle 10 to automatically drive from a driving start position (work start position) to a driving end position (work end position) according to a target route that is generated and set in advance in the operation terminal 20. For example, the driving processing unit 111 causes the work vehicle 10 to automatically drive straight along a straight route and to automatically drive turning along a turning route. In addition, the driving processing unit 111 automatically drives the work vehicle 10 along a plurality of work routes that are included in the target route and that cause the work vehicle 10 to perform predetermined work, and a plurality of non-work routes that connect the work routes.

[0036] Furthermore, the driving processing unit 111 automatically drives the work vehicle 10 along the target route so as to follow a target position that is set at a predetermined position a predetermined distance away from the current position of the work vehicle 10 in the traveling direction.

[0037] An example of a general automated driving method will now be described with reference to Figures 3A and 3B. Figures 3A and 3B show a straight route r1, a turning route r2 following the straight route r1, and a straight route r3 following the turning route r2. A target position Px (forward gaze point) is set for the work vehicle 10 at a position a predetermined distance L1 away from the current position Pv in the traveling direction.

[0038] As shown in FIG. 3A, when the work vehicle 10 travels along a straight route r1, the driving processing unit 111 automatically drives the work vehicle 10 along the straight route r1 so as to follow a target position Px set on the straight route r1. Also, as shown in FIG. 3B, when the work vehicle 10 travels along a turning route r2, the driving processing unit 111 automatically drives the work vehicle 10 along the turning route r2 so as to follow a target position Px set on the turning route r2. Note that the target position Px is set on the target route, for example. In this case, the target position Px moves along the straight route r1 as the work vehicle 10 travels, and when it reaches the end position Pe of the straight route r1 (the start position P1 of the turning route r2), it moves onto the turning route r2.

[0039] In the automated driving method, the automated driving system 1 according to this embodiment has a characteristic configuration for setting a target position Px. Specifically, the setting processing unit 112 sets the target position Px based on the angle (angle d1, described below) between a first route along which the work vehicle 10 is traveling and a second route that continues from the first route, and the distance (distance La, described below) from the current position of the work vehicle 10 to the end position of the first route (start position of the second route). A specific method for setting the target position Px will be described later.

[0040] The vehicle speed control processing unit 113 controls the traveling speed (vehicle speed) of the automatically traveling work vehicle 10. Specifically, the vehicle speed control processing unit 113 reduces the vehicle speed of the work vehicle 10 when the distance La from the current position of the work vehicle 10 to the end position of the first route (start position of the second route) is less than a threshold distance (threshold distance Lth1 described below), when the angle d1 formed is less than a threshold angle (threshold angle Dth described below), or when the length of the second route (length Lb described below) is less than a threshold length (threshold length Lth2 described below). A specific method for controlling the vehicle speed of the work vehicle 10 will be described later.

[0041] [Operation terminal 20] 1, the operation terminal 20 is an information processing device including an operation control unit 21, a storage unit 22, an operation display unit 23, and a communication unit 24. The operation terminal 20 may be configured as a mobile terminal such as a tablet terminal or a smartphone.

[0042] The communication unit 24 is a communication interface that connects the operation terminal 20 to the communication network N1 via a wired or wireless connection and performs data communication in accordance with a predetermined communication protocol with external devices such as one or more work vehicles 10 via the communication network N1.

[0043] The operation display unit 23 is a user interface equipped with a display unit such as a liquid crystal display or organic EL display that displays various information, and an operation unit such as a touch panel, mouse, or keyboard that accepts operations. The worker can operate the operation unit on the operation screen displayed on the display unit to register various information (such as work vehicle information, field information, and work information, which will be described later). The worker can also operate the operation unit to give instructions to the work vehicle 10 to start work, stop traveling, and so on. Furthermore, from a location away from the work vehicle 10, the worker can grasp the traveling status of the work vehicle 10, which is automatically traveling along a target route within the field F, by looking at the traveling trajectory displayed on the operation terminal 20 and images captured by the camera.

[0044] The storage unit 22 is a non-volatile storage unit such as an HDD, SSD, or flash memory that stores various types of information. The storage unit 22 stores a control program for causing the operation control unit 21 to execute various control processes. For example, the control program is non-temporarily recorded on a computer-readable recording medium such as a CD or DVD, and is read by a predetermined reading device (not shown) and stored in the storage unit 22. The control program may be downloaded to the operation terminal 20 from a server (not shown) via the communication network N1 and stored in the storage unit 22.

[0045] The operation control unit 21 has control devices such as a CPU, a ROM, and a RAM. The CPU is a processor that executes various types of arithmetic processing. The ROM is a non-volatile storage unit in which control programs such as a BIOS and an OS that cause the CPU to execute various types of arithmetic processing are stored in advance. The RAM is a volatile or non-volatile storage unit that stores various types of information and is used as a temporary storage memory (work area) for the various types of processing executed by the CPU. The operation control unit 21 controls the operation terminal 20 by having the CPU execute various control programs that are stored in advance in the ROM or the storage unit 22.

[0046] 1, the operation control unit 21 includes various processing units such as a registration processing unit 211, a setting processing unit 212, a generation processing unit 213, and an output processing unit 214. The operation control unit 21 functions as the various processing units by executing various processes in accordance with the control program using the CPU. Some or all of the processing units may be configured with electronic circuits. The control program may be a program for causing multiple processors to function as the processing units.

[0047] The registration processing unit 211 registers various setting information for causing the work vehicle 10 to perform autonomous driving. Specifically, the registration processing unit 211 registers information relating to the work vehicle 10 (hereinafter referred to as work vehicle information). The registration processing unit 211 registers information such as the type (model) of the work vehicle 10, the position where the positioning antenna 164 is attached on the work vehicle 10, the type of work implement 14, the size and shape of the work implement 14, the position of the work implement 14 relative to the work vehicle 10, the vehicle speed and engine rotation speed of the work vehicle 10 while working, and the vehicle speed and engine rotation speed of the work vehicle 10 while turning, by the operator performing a registration operation on the operation terminal 20.

[0048] For example, the registration processing unit 211 causes the operation display unit 23 to display the menu screen D1 shown in Fig. 6. The worker selects, for example, "Work machine registration" on the menu screen D1 to register work machine information related to the work machine 14.

[0049] The registration processing unit 211 also registers information relating to the field F (hereinafter referred to as field information). The registration processing unit 211 registers information such as the position and shape of the field F, the travel start position where work begins and the travel end position where work ends, and the work direction by performing a registration operation on the operation terminal 20. The work direction refers to the direction in which the work vehicle 10 will travel while working with the work implement 14 in the work area excluding the non-work area of ​​the field F. For example, the worker registers field information by selecting "Field registration" on the menu screen D1.

[0050] Information on the position and shape of the field F can be automatically obtained, for example, by having a worker get into the work vehicle 10 and drive it around the perimeter of a specified area AR (see Figure 4), and recording the changes in the position information of the positioning antenna 164 at that time.

[0051] Specifically, the registration processing unit 211 acquires position information of the current position of the work vehicle 10 based on the positioning information measured by the positioning unit 16. When the registration processing unit 211 acquires the position information, it registers it in the storage unit 22. For example, when an operator manually drives (teaching drives) the work vehicle 10 in a predetermined area AR when registering a field (see FIG. 4), the registration processing unit 211 acquires position information of the work vehicle 10 at predetermined sampling intervals. The black dots shown in FIG. 4 correspond to the position information of each positioning point.

[0052] Furthermore, while the worker is conducting teaching travel with the work vehicle 10, the work implement 14 may be lowered to perform a predetermined task. The registration processing unit 211 sequentially registers the position information of the work vehicle 10 while the work vehicle 10 is conducting teaching travel.

[0053] When teaching travel ends, the registration processing unit 211 registers the field based on the position information. For example, as shown in FIG. 4, the registration processing unit 211 obtains approximate lines connecting the travel trajectory (plot) traveled by the work vehicle 10, generates intersections (interpolated points a1 to a6) between extensions of adjacent approximate lines, and registers the area enclosed by the lines connecting the generated interpolated points a1 to a6 as field F. Note that the operator can change the positions of the interpolated points or add interpolated points. In this way, the registration processing unit 211 registers field F as a work area based on position information acquired by the operator's manual travel operation of the work vehicle 10.

[0054] The registration processing unit 211 also registers information relating to how work will be carried out specifically (hereinafter referred to as work information). The registration processing unit 211 is configured to be able to register, as work information, whether or not cooperative work will be carried out between an unmanned work vehicle 10 and a manned work vehicle 10, the skip number which is the number of work routes to skip when the work vehicle 10 turns on the headland, the width of the headland, and the width of the non-work area. For example, the worker selects "Route Creation" on the menu screen D1 to register information about the travel route.

[0055] The setting processing unit 212 sets a reference line (first reference line Ra) that serves as a reference when generating a target route for the work vehicle 10. Specifically, the setting processing unit 212 sets the first reference line Ra, which includes a plurality of partial straight routes (straight line segments), based on a plurality of pieces of position information acquired when registering the field. For example, the setting processing unit 212 sets the first reference line Ra based on position information indicating the travel trajectory of the work vehicle 10, which is acquired by the worker's manual travel operation (teaching travel operation) when registering the field. Below, a method for generating a target route corresponding to an area A1 where work is performed while turning in the field F shown in FIG. 5 will be described as an example.

[0056] First, the setting processing unit 212 sets a second reference line Rb including partial curves (curve segments) based on multiple pieces of position information acquired when registering the field. Specifically, as shown in FIG. 7, the setting processing unit 212 sets the second reference line Rb by connecting, with approximate straight lines and approximate curved lines, travel trajectories (plots) corresponding to the position information of the work vehicle 10 acquired during teaching travel (see FIG. 4). The plots included in the second reference line Rb shown in FIG. 7 indicate the connection points between the partial straight line path (x1, x2) of the approximate straight line and the partial curve (y1, y2) of the approximate curve. For example, when three consecutive plots are connected with two straight lines, if the angle between the two straight lines is equal to or greater than a predetermined angle, the three points are approximated by a single straight line, and if the angle between the two straight lines is less than the predetermined angle, the three points are approximated by a single curved line.

[0057] Next, the setting processing unit 212 sets the first reference line Ra based on the second reference line Rb. Specifically, the setting processing unit 212 converts the curve (turning path) included in the second reference line Rb into a straight line based on the turning angle. In the example shown in FIG. 7, the setting processing unit 212 converts the partial curve y1 (curve segment) into one or more partial straight path segments based on the turning angles corresponding to the partial straight path x1 and the partial straight path x2. A specific example of a method for converting a partial curve into a partial straight path segment will be described below.

[0058] 8A, when the turning angle θ of the partial straight path x1 and the partial straight path x2 is less than a first predetermined angle (e.g., 3 degrees), the setting processing unit 212 determines the intersection x0 between the extension line of the partial straight path x1 and the extension line of the partial straight path x2. Then, the setting processing unit 212 deletes the partial curve y1 and replaces it with the partial straight path x1 and the partial straight path x2 that are connected at the intersection x0. In other words, the setting processing unit 212 replaces the partial straight path x1, the partial curve y1, and the partial straight path x2 with the two extended partial straight paths x1 and x2.

[0059] 8B, when the turning angle θ in the partial straight path x1 and the partial straight path x2 is equal to or greater than a first predetermined angle (e.g., 3 degrees) and less than a second predetermined angle (e.g., 6 degrees), the setting processing unit 212 replaces the partial curve y1 with one complementary line (partial straight path x12). That is, the setting processing unit 212 replaces the partial straight path x1, the partial curve y1, and the partial straight path x2 with three partial straight paths x1, x12, and x2.

[0060] 8C, when the turning angle θ of the partial straight path x1 and the partial straight path x2 is equal to or greater than a second predetermined angle (e.g., 6 degrees), the setting processing unit 212 replaces the partial curve y1 with a plurality of complementary lines. Specifically, the setting processing unit 212 determines the number of complementary points by dividing the turning angle θ by the set angle, and arranges the calculated number of complementary points at equal intervals on the partial curve y1. In FIG. 8C, the setting processing unit 212 arranges two complementary points on the partial curve y1, and replaces the partial curve y1 with three partial straight path lines x121 to x123. The setting processing unit 212 replaces the partial straight path x1, the partial curve y1, and the partial straight path x2 with five partial straight path lines x1, x121, x122, x123, and x2.

[0061] The setting processing unit 212 converts each partial curve included in the second reference line Rb into a partial straight line path using the method described above. Then, as shown in Fig. 7, the setting processing unit 212 sets a first reference line Ra consisting of a plurality of straight lines (partial straight line paths) based on the second reference line Rb. In the first reference line Ra shown in Fig. 7, the partial curve y1 of the second reference line Rb is converted into partial straight line paths x11 to x13, and the partial curve y2 of the second reference line Rb is converted into partial straight line paths x21 to x23. In other words, the first reference line Ra is made up of eight partial straight line paths.

[0062] As described above, the setting processing unit 212 sets the first reference line Ra based on the second reference line Rb including partial curves generated based on multiple pieces of position information. Furthermore, the setting processing unit 212 sets the second reference line Rb including partial straight paths and partial curves based on multiple pieces of position information, converts the partial curves into one or more partial straight paths according to the angle (or turning angle) formed by the two partial straight paths, and sets the first reference line Ra by connecting the partial straight path included in the second reference line Rb with the partial straight path obtained by converting the partial curve included in the second reference line Rb. Furthermore, the setting processing unit 212 determines the number of partial straight paths into which the partial curves are converted based on the angle (turning angle) formed by the two partial straight paths.

[0063] The generation processing unit 213 generates a target route along which the work vehicle 10 will automatically travel in the field F. The generation processing unit 213 executes the target route generation process when the operator selects "Create route" on the menu screen D1 (see FIG. 6) and receives an instruction to generate a target route. Specifically, the generation processing unit 213 generates a target route based on the first reference line Ra. For example, as shown in FIG. 9, the generation processing unit 213 translates each of the multiple partial straight-line routes that make up the first reference line Ra by a predetermined distance W1, and connects each of the multiple partial straight-line routes x31 to x38 that correspond to the multiple partial straight-line routes after the translation to generate a target route R1.

[0064] After generating the target route R1 for the work vehicle 10, the generation processing unit 213 registers the target route R1 in association with the field F. Note that the generation processing unit 213 is capable of generating and registering multiple target routes for one field F according to the work content.

[0065] The output processing unit 214 outputs route data of the target route to the work vehicle 10. For example, when a worker selects a desired target route on the operation screen and issues a command to start work, the output processing unit 214 outputs the route data of the selected target route to the work vehicle 10.

[0066] The work vehicle 10 is configured so that route data for the target route generated in the operation terminal 20 is transferred to the work vehicle 10 and stored in the memory unit 12, and the work vehicle 10 is able to travel autonomously along the target route while detecting the current position of the work vehicle 10 using the positioning antenna 164. Note that the current position of the work vehicle 10 may normally coincide with the position of the positioning antenna 164.

[0067] When predetermined start conditions are met, and the worker presses the work start button on the operation screen to give a work start instruction, the work vehicle 10 starts automatic driving by the driving processing unit 111 and starts work using the work implement 14 (see FIG. 2). For example, the start of automatic driving of the work vehicle 10 is permitted on the condition that the current position of the work vehicle 10 is within a set distance from the driving start position and the vehicle heading is within a set heading. Note that the start conditions for permitting automatic driving of the work vehicle 10 are not limited to the above conditions.

[0068] The driving processing unit 111 of the work vehicle 10 automatically drives the work vehicle 10 from the driving start position to the driving end position according to the target route acquired from the operation terminal 20.

[0069] The operation terminal 20 may be able to access a website (agricultural support site) for an agricultural support service provided by a server (not shown) via the communication network N1. In this case, the operation terminal 20 can function as an operation terminal for the server by executing a browser program by the operation control unit 21. The server is provided with the above-mentioned processing units and executes each process.

[0070] [How to set target position Px] A specific method for setting the target position Px according to this embodiment will be described. In Fig. 10, the turning path r2 shown in Fig. 3A is represented by partial straight path paths r21 to r23, which are approximate straight lines. The path shown in Fig. 10 is an example of the target path R1 (see Fig. 9) according to this embodiment. The turning path of the present invention is made up of a plurality of consecutive straight path paths, and the second path of the present invention may be included in the plurality of straight path paths.

[0071] The setting processing unit 112 sets the target position Px at a predetermined position a predetermined distance from the current position in the traveling direction, based on the angle between a first route on which the work vehicle 10 is traveling and a second route that continues from the first route, and the distance from the current position of the work vehicle 10 to the end position of the first route (start position of the second route). In the example shown in Fig. 10, the straight route r1 corresponds to the first route, and the partial straight route r21 corresponds to the second route.

[0072] In the example shown in Figure 10, the setting processing unit 112 sets the target position Px based on the angle d1 between the straight path r1 on which the work vehicle 10 is traveling and the partial straight path r21, and the distance La from the current position Pv of the work vehicle 10 to the end position Pe of the straight path r1 (the starting position P1 of the partial straight path r21).

[0073] For example, when the angle d1 is large, the work vehicle 10 can be steered along the target route while traveling approximately straight, so the target position Px can be set at a position far from the work vehicle 10. In other words, when the target position Px is set at a position far from the work vehicle 10, even if the target position Px moves quickly from the straight route r1 onto the partial straight route r21, the work vehicle 10 can travel straight continuously along the straight route r1 and the partial straight route r21, so travel accuracy relative to the target route can be maintained.

[0074] On the other hand, when the angle d1 is small, it is desirable to set the target position Px at a position close to the work vehicle 10 in order to have the work vehicle 10 travel accurately along the straight path r1 and the partial straight path r21. For example, when the angle d1 is small and the target position Px is set at a position far from the work vehicle 10, the target position Px will move from the straight path r1 onto the partial straight path r21 early, causing the work vehicle 10 to deviate early from the straight path r1 and travel more inward than the target path toward the partial straight path r21, thereby reducing travel accuracy.

[0075] In this way, when the work vehicle 10 moves from the first route to the second route, the angle d1 formed between the first route and the second route affects the traveling accuracy.

[0076] Therefore, the setting processing unit 112 sets the predetermined distance L1 of the target position Px to be longer as the included angle d1 is larger, and sets the predetermined distance L1 of the target position Px to be shorter as the included angle d1 is smaller. For example, when the included angle d1 is greater than or equal to the threshold angle Dth, the setting processing unit 112 sets the predetermined distance L1 of the target position Px to the distance L11, and when the included angle d1 is less than the threshold angle Dth, the setting processing unit 112 sets the predetermined distance L1 of the target position Px to the distance L12 (L12 < L11). That is, the setting processing unit 112 sets the target position Px at a position farther from the work vehicle 10 as the included angle d1 is larger, and sets the target position Px at a position closer to the work vehicle 10 as the included angle d1 is smaller. Thereby, the work vehicle 10 can be accurately automatically traveled along the straight travel path r1 and the partial straight line path r21.

[0077] In addition, the setting processing unit 112 sets the target position Px according to the distance of the distance La. For example, when the distance La is greater than or equal to the threshold distance Lth1, the setting processing unit 112 sets the target position Px on the straight travel path r1, and when the distance La is less than the threshold distance Lth1, the setting processing unit 112 sets the target position Px on the extension line of the straight travel path r1 or on the partial straight line path r21. If the distance La is greater than or equal to the threshold distance Lth1, since there is a certain amount of time margin until the work vehicle 10 moves from the straight travel path r1 to the next partial straight line path r21, by setting the target position Px on the straight travel path r1, the straight travel path r1 and the partial straight line path r21 can be accurately automatically traveled. Therefore, when the distance La is greater than or equal to the threshold distance Lth1, the setting processing unit 112 sets the target position Px on the straight travel path r1 regardless of the included angle d1.

[0078] On the other hand, when the distance La is less than the threshold distance Lth1 (when the work vehicle 10 is close to the starting position P1 of the turning path r2), the target position Px may suddenly move onto the turning path r2, resulting in a large steering amount. Therefore, when the formed angle d1 is less than the threshold angle Dth, and the distance La is less than the threshold distance Lth1, the setting processing unit 112 sets the target position Px on an extension of the straight path r1. This allows the work vehicle 10 to move smoothly onto the turning path r2. Furthermore, because the steering amount does not become large when the formed angle d1 is equal to or greater than the threshold angle Dth, the setting processing unit 112 sets the target position Px on the turning path r2 when the distance La is less than the threshold distance Lth1. Note that the setting processing unit 112 may set the target position Px on the turning path r2 when the distance La becomes less than the threshold distance Lth1.

[0079] In another embodiment, when setting the target position Px on the second route, the setting processing unit 112 may move the target position Px on the second route so that the sum of the distance La and the distance Lc from the end position Pe of the straight route r1 (the start position P1 of the turning route r2) to the target position Px does not change. For example, as shown in Figures 11A and 11B, the setting processing unit 112 sets the target position Px on the second route so that the sum of the distance La and the distance Lc (La + Lc) does not change as the work vehicle 10 travels along the straight route r1.

[0080] As another embodiment of the configuration shown in FIGS. 11A and 11B, the setting processing unit 112 may set the target position Px such that the total (La + Lc) changes according to the angle d1 formed by the straight path r1 and the partial straight path r21. For example, when the angle d1 is large (for example, when d1 ≧ Dth), similar to the configuration shown in FIGS. 11A and 11B, the setting processing unit 112 sets the target position Px on the partial straight path r21 so that the total (La + Lc) does not change. On the other hand, when the angle d1 is small (for example, when d1 < Dth), since the steering amount of the turn becomes large, the setting processing unit 112 makes the movement amount (increase amount of the distance Lc) of the target position Px on the partial straight path r21 smaller as the target position Px is closer to the start position P1, and makes the movement amount (increase amount of the distance Lc) of the target position Px on the partial straight path r21 larger as the target position Px moves away from the start position P1. That is, the setting processing unit 112 sets the target position Px on the partial straight path r21 such that the increase rate of the distance Lc gradually increases. For example, when the angle d1 is large, the setting processing unit 112 sets the target position Px on the partial straight path r21 so that the total (La + Lc) is maintained at 1 m. On the other hand, when the angle d1 is small, the setting processing unit 112 sets the target position Px on the partial straight path r21 such that the increase rate of the distance Lc gradually increases until the total (La + Lc) reaches 3 m.

[0081] As another embodiment of the configuration shown in FIGS. 11A and 11B, the setting processing unit 112 may set the target position Px so that the sum (La + Lc) changes depending on the length Lb (see FIG. 10) of the partial straight-line path r21. For example, when the length Lb of the partial straight-line path r21 is short, the setting processing unit 112 sets the target position Px on the partial straight-line path r21 so that the sum (La + Lc) does not change, as in the configuration shown in FIGS. 11A and 11B. On the other hand, when the length Lb of the partial straight-line path r21 is long, the setting processing unit 112 decreases the movement amount of the target position Px on the partial straight-line path r21 (the increase in the distance Lc) as the target position Px is closer to the starting position P1, and increases the movement amount of the target position Px on the partial straight-line path r21 (the increase in the distance Lc) as the target position Px moves away from the starting position P1. That is, the setting processing unit 112 sets the target position Px on the partial straight-line path r21 so that the rate of increase of the distance Lc gradually increases. For example, when the length Lb of the partial straight path r21 is short, the setting processing unit 112 sets the target position Px on the partial straight path r21 so that the total (La+Lc) is maintained at 1 m. On the other hand, when the length Lb of the partial straight path r21 is long, the setting processing unit 112 sets the target position Px on the partial straight path r21 so that the rate of increase of the distance Lc gradually increases until the total (La+Lc) becomes 3 m.

[0082] [Vehicle speed control processing] In order to further improve the accuracy of turning from the straight path r1 to the partial straight path r21, the vehicle speed control processing unit 113 may control the vehicle speed of the work vehicle 10 in accordance with the distance La from the current position Pv of the work vehicle 10 to the end position Pe of the straight path r1 (start position P1 of the partial straight path r21). Specifically, the vehicle speed control processing unit 113 maintains the vehicle speed of the work vehicle 10 at a set vehicle speed when the distance La is equal to or greater than a threshold distance Lth1, and reduces the vehicle speed of the work vehicle 10 when the work vehicle 10 approaches the end position Pe of the straight path r1 (start position P1 of the turning path r2) and the distance La becomes less than the threshold distance Lth1. The vehicle speed control processing unit 113 may also gradually reduce the vehicle speed as the distance La becomes smaller.

[0083] In another embodiment, the vehicle speed control processing unit 113 may maintain the vehicle speed of the work vehicle 10 at a set vehicle speed when the formed angle d1 is equal to or greater than the threshold angle Dth, and may reduce the vehicle speed of the work vehicle 10 when the formed angle d1 is less than the threshold angle Dth. For example, when the formed angle d1 is less than the threshold angle Dth, the vehicle speed control processing unit 113 may reduce the vehicle speed of the work vehicle 10 when the distance La becomes less than the threshold distance Lth1.

[0084] In another embodiment, the vehicle speed control processing unit 113 may control the vehicle speed of the work vehicle 10 in accordance with the length Lb of the partial straight path r21. Specifically, the vehicle speed control processing unit 113 maintains the vehicle speed of the work vehicle 10 at a set vehicle speed when the length Lb of the partial straight path r21 next to the straight path r1 is equal to or greater than the threshold length Lth2. In contrast, when the length Lb of the partial straight path r21 is less than the threshold length Lth2, the vehicle speed control processing unit 113 decelerates the vehicle speed of the work vehicle 10, for example, when the work vehicle 10 travels along the straight path r1 and the target position Px reaches the end position Pe of the straight path r1. Furthermore, the vehicle speed control processing unit 113 may slow the vehicle speed the shorter the length Lb of the partial straight path r21.

[0085] Furthermore, when the length Lb of the partial straight path r21 is less than the threshold length Lth2, the vehicle speed control processing unit 113 may reduce the vehicle speed of the work vehicle 10, for example, when the work vehicle 10 is traveling along the straight path r1 and the distance La becomes less than the threshold distance Lth1. That is, the vehicle speed control processing unit 113 may reduce the vehicle speed of the work vehicle 10 when the length Lb of the partial straight path r21 is less than the threshold length Lth2 and the distance La becomes less than the threshold distance Lth1. Furthermore, when the length Lb of the partial straight path r21 is equal to or greater than the threshold length Lth2, the vehicle speed control processing unit 113 may maintain the vehicle speed of the work vehicle 10 at a set vehicle speed regardless of the distance La.

[0086] As another embodiment, the vehicle speed control processing unit 113 may control the vehicle speed of the work vehicle 10 according to the angle d1 formed between the straight travel path r1 and the partial straight line path r21. Specifically, when the angle d1 is large (for example, when d1 ≧ Dth), the vehicle speed control processing unit 113 may maintain the vehicle speed of the work vehicle 10 at the set vehicle speed, and when the angle d1 is small (for example, when d1 < Dth), the vehicle speed of the work vehicle 10 may be decelerated. Further, the vehicle speed control processing unit 113 may decrease the vehicle speed as the angle d1 becomes smaller.

[0087] In addition, the vehicle speed control processing unit 113 may decelerate the vehicle speed according to the operator's instruction. For example, the vehicle speed control processing unit 113 receives a user operation for presetting whether to enable or disable a process of decelerating the vehicle speed of the work vehicle 10 when the distance La becomes less than the threshold distance Lth1 ( "deceleration process according to distance"). When the "deceleration process according to distance" is preset to be enabled in advance, the vehicle speed control processing unit 113 decelerates the vehicle speed as the work vehicle 10 approaches the vicinity of the end of the first path. On the other hand, if the operator does not desire the vehicle speed to decrease each time the work vehicle 10 approaches the vicinity of the end of the first path, for example, the operator may preset the "deceleration process according to distance" to be disabled. In this case, the vehicle speed control processing unit 113 decelerates the vehicle speed of the work vehicle 10 regardless of the distance La, for example, when the angle d1 formed between the straight travel path r1 and the partial straight line path r21 is less than the threshold angle Dth, or when the length Lb of the partial straight line path r21 is less than the threshold length Lth2.

[0088] The above-described [method for setting the target position Px] and [vehicle speed control processing] can be appropriately combined. Specifically, when the angle d1 is large (for example, when d1 ≧ Dth), the vehicle control device 11 sets the target position Px to a far position and maintains the vehicle speed at the set vehicle speed, and when the angle d1 is small (for example, when d1 < Dth), the vehicle control device 11 sets the target position Px to a near position and decelerates the vehicle speed.

[0089] In addition, when the distance La from the current position Pv of the work vehicle 10 to the end position Pe of the straight path r1 (the starting position P1 of the partial straight path r21) is equal to or greater than the threshold distance Lth1, the vehicle control device 11 sets the target position Px on the straight path r1 and maintains the vehicle speed at the set vehicle speed, and when the distance La is less than the threshold distance Lth1, sets the target position Px on an extension of the straight path r1 or on the partial straight path r21 and decelerates the vehicle speed.

[0090] In the above example, the straight path r1 is described as the first path of the present invention, and the partial straight path r21 is described as the second path of the present invention, but both the first path and the second path may be the turning path r2. For example, in the example shown in Fig. 10, the partial straight path r21 may be the first path and the partial straight path r22 may be the second path, or the partial straight path r22 may be the first path and the partial straight path r23 may be the second path.

[0091] [Automatic driving processing] Hereinafter, an example of the automatic driving process executed by the automatic driving system 1 will be described with reference to FIG.

[0092] The present invention can be understood as an invention of an automatic driving method that executes one or more steps included in the automatic driving process. Furthermore, one or more steps included in the automatic driving process described herein may be omitted as appropriate. Furthermore, the order of execution of each step in the automatic driving process may be different as long as the same operational effect is achieved. Furthermore, while the description here takes as an example a case where the vehicle control device 11 executes each step in the automatic driving process, another embodiment can also be an automatic driving method in which one or more processors execute each step in the automatic driving process in a distributed manner.

[0093] <Step S1> In step S1, the vehicle control device 11 determines whether it has acquired a work start instruction. When the vehicle control device 11 acquires the work start instruction from the operation terminal 20 (S1: Yes), it transfers the process to step S2. The vehicle control device 11 waits until it acquires the work start instruction (S1: No).

[0094] <Step S2> In step S2, the vehicle control device 11 starts the automatic driving process. Specifically, the vehicle control device 11 causes the work vehicle 10 to start automatic driving according to the target route corresponding to the route data acquired from the operation terminal 20. Here, as shown in FIG. 3A, it is assumed that the work vehicle 10 starts automatic driving on the first route (straight route r1).

[0095] <Step S3> In step S3, the vehicle control device 11 determines whether the angle d1 (see FIG. 10) formed by the straight route r1 and the partial straight route r21 (second route) following the straight route r1 is less than the threshold angle Dth (d1 < Dth). When the vehicle control device 11 determines that the formed angle d1 is less than the threshold angle Dth, it transfers the process to step S4. On the other hand, when the vehicle control device 11 determines that the formed angle d1 is greater than or equal to the threshold angle Dth, it transfers the process to step S31.

[0096] <Step S31> In step S31, the vehicle control device 11 sets a target position Px (forward fixation point) at a position separated from the current position Pv of the work vehicle 10 by a predetermined distance L1 (here L1 = L11) in the traveling direction side (see FIG. 3A). For example, the vehicle control device 11 sets the target position Px at a position of distance L11 on the straight route r1. The vehicle control device 11 automatically drives the straight route r1 so that the work vehicle 10 follows the target position Px on the straight route r1.

[0097] <Step S32> In step S32, the vehicle control device 11 determines whether the target position Px on the straight - ahead path r1 has reached the end position Pe (the start position P1 of the turning path r2) (see FIG. 10) of the straight - ahead path r1. When the vehicle control device 11 determines that the target position Px has reached the end position Pe (the start position P1), it causes the process to shift to step S33. The vehicle control device 11 continues the automatic driving on the straight - ahead path r1 until the target position Px reaches the end position Pe (the start position P1) (S32: No).

[0098] <Step S33> In step S33, the vehicle control device 11 moves (sets) the target position Px onto the partial straight - line path r21. The vehicle control device 11 automatically drives the partial straight - line path r21 so that the work vehicle 10 follows the target position Px on the partial straight - line path r21. After step S33, the vehicle control device 11 causes the process to shift to step S8.

[0099] As another embodiment of steps S32 and S33, the vehicle control device 11 may move (set) the target position Px onto the partial straight - line path r21 when the current position Pv of the work vehicle 10 reaches the end position Pe (the start position P1). Thereby, the work can be surely performed up to the end position Pe of the straight - ahead path r1.

[0100] <Step S4> In step S4, the vehicle control device 设定s the target position Px at a position that is separated from the current position Pv of the work vehicle 10 by a predetermined distance L1 (here, L1 = L12, L12 < L11) in the traveling direction side (see FIG. 3A). For example, the vehicle control device 设定s the target position Px at the position of the distance L12 on the straight - ahead path r1. The vehicle control device 11 automatically drives the straight - ahead path r1 so that the work vehicle 10 follows the target position Px on the straight - ahead path r1.

[0101] <Step S5> In step S5, the vehicle control device 11 determines whether the distance La from the current position Pv of the work vehicle 10 to the end position Pe of the straight route r1 (start position P1 of the partial straight route r21) is less than the threshold distance Lth1. The threshold distance Lth1 is set to a distance shorter than the distance L11. If the vehicle control device 11 determines that the distance La is less than the threshold distance Lth1 (S5: Yes), it transitions the processing to step S6. If the distance La is equal to or greater than the threshold distance Lth1, the vehicle control device 11 continues automatic traveling on the straight route r1 until the distance La becomes less than the threshold distance Lth1 (S5: No).

[0102] <Step S6> In step S6, the vehicle control device 11 reduces the vehicle speed of the work vehicle 10. For example, if the distance La is less than the threshold distance Lth1 at the start of travel on the current travel route, the vehicle control device 11 reduces the vehicle speed of the work vehicle 10 at that time. Furthermore, if the distance La is equal to or greater than the threshold distance Lth1, the vehicle control device 11 reduces the vehicle speed of the work vehicle 10 from the set vehicle speed for straight travel to the set vehicle speed for turning travel when the distance La reaches the threshold distance Lth1.

[0103] In another embodiment, the vehicle control device 11 may reduce the vehicle speed of the work vehicle 10 when the length Lb of the partial straight path r21 is less than the threshold length Lth2 and the distance La is less than the threshold distance Lth1. The vehicle control device 11 may omit the vehicle speed reduction process (maintain the set vehicle speed for straight-ahead driving) when the length Lb of the partial straight path r21 is equal to or greater than the threshold length Lth2.

[0104] <Step S7> In step S7, the vehicle control device 11 moves (sets) the target position Px on the partial straight path r21. For example, the vehicle control device 11 may set the target position Px on the partial straight path r21 when the distance La reaches the threshold distance Lth1. As a result, the vehicle control device 11 causes the work vehicle 10 to automatically travel along the partial straight path r21 at the vehicle speed after deceleration so as to follow the target position Px on the partial straight path r21. Furthermore, the vehicle control device 11 may increase the predetermined distance L1 from the work vehicle 10 to the target position Px as the distance La becomes shorter. In other words, the vehicle control device 11 may move the target position Px set on the partial straight path r21 away as the work vehicle 10 approaches the end position Pe of the straight path r1.

[0105] In another embodiment, the vehicle control device 11 may set the target position Px on an extension of the straight route r1.

[0106] In another embodiment, the vehicle control device 11 may set the target position Px on an extension of the straight path r1, and when the current position Pv of the work vehicle 10 reaches the terminal position Pe (starting position P1), move (set) the target position Px onto the partial straight path r21.

[0107] The order of steps S6 and S7 is not limited. After step S7, the vehicle control device 11 advances the process to step S8.

[0108] <Step S8> In step S8, the vehicle control device 11 determines whether the work vehicle 10 has reached the work end position. When the vehicle control device 11 determines that the work vehicle 10 has reached the work end position (S8: Yes), it ends the automatic driving process. When the vehicle control device 11 determines that the work vehicle 10 has not reached the work end position (S8: No), it shifts the process to step S3. The vehicle control device 11 repeatedly executes the above-described process until the work vehicle 10 reaches the work end position (S8: No). For example, when returning to step S3, the vehicle control device 11 determines whether an angle d1 formed by a partial straight path r21 (first path) and a partial straight path r22 (second path) following the partial straight path r21 (see FIG. 10) is less than a threshold angle Dth (d1 < Dth), and executes subsequent processes.

[0109] In this way, the vehicle control device 11 repeatedly executes the above-described process from the work start position to the work end position, and automatically drives the work vehicle 10 along the target path while executing the setting process of the target position Px and the control process of the vehicle speed.

[0110] As described above, the automatic driving system 1 according to the present embodiment is a system that automatically drives the work vehicle 10 along a target path including a straight traveling path and a turning path. Specifically, the automatic driving system 1 sets a target position Px at a predetermined position separated from the current position Pv in the traveling direction by a predetermined distance L1 based on an angle d1 formed by a first path in which the work vehicle 10 is traveling and a second path following the first path, and the distance La from the current position Pv of the work vehicle 10 to the end position of the first path, and causes the work vehicle 10 to travel so as to follow the target position Px.

[0111] For example, when the included angle d1 (see FIG. 10) is greater than or equal to the threshold angle Dth, by setting the predetermined distance L1 of the target position Px to the long distance L11, even if the target position Px moves from the first path to the second path, the work vehicle 10 can be continuously driven straight ahead. Further, when the included angle d1 is less than the threshold angle Dth, by setting the predetermined distance L1 of the target position Px to the short distance L12 (L12 < L11), the target position Px moves to the second path earlier from the first path, so that the work vehicle 10 can be driven toward the second path earlier. Further, when the included angle d1 is less than the threshold angle Dth and the distance La is less than the predetermined distance L1, by setting the target position Px on the extension line of the first path or on the second path, the work vehicle 10 can be smoothly moved (turned) from the first path to the second path. Therefore, the work vehicle 10 can be accurately automatically driven according to the first path and the second path.

[0112] [Other Embodiments] The present invention is not limited to the above-described embodiments. Other embodiments of the present invention will be described below.

[0113] The automatic driving system 1 according to another embodiment may be configured to control the steering angle of the work vehicle 10 based on the length of the second path following the first path on which the work vehicle 10 is traveling and the lateral deviation from the current position Pv of the work vehicle 10 to the first path.

[0114] Specifically, as shown in FIG. 13, the vehicle control device 11 controls the steering angle of the work vehicle 10 based on the length Lb of the partial straight path r21 following the straight path r1 on which the work vehicle 10 is traveling and the lateral deviation t1 from the current position Pv of the work vehicle 10 to the straight path r1. In this configuration, the vehicle control device 11 stops the travel control (steering control) by the target position Px (forward viewing point) and executes the steering control by the deviation t1.

[0115] For example, the vehicle control device 11 pre-registers the steering angle of the steering wheel 137 corresponding to the deviation t1 and acquires the steering angle corresponding to the current deviation t1 by referring to the registered information. Then, when the length Lb of the partial straight path r21 is less than the threshold length Lth2, the vehicle control device 11 performs steering control in accordance with the steering angle corresponding to the deviation t1. Note that when the length Lb of the partial straight path r21 is equal to or greater than the threshold length Lth2, the vehicle control device 11 performs driving control (steering control) based on the target position Px (head gaze point). In this way, when the length of the next driving path is short, the vehicle control device 11 does not perform driving control based on the target position Px (head gaze point), but performs driving control based on the deviation t1.

[0116] The above configuration enables automatic driving along the target route while reducing hunting, particularly when the vehicle speed of the work vehicle 10 is slow. Note that even if deviation t1 occurs, the vehicle control device 11 does not need to execute steering control based on deviation t1 if the vehicle heading is heading in the direction of the target route.

[0117] The above configuration may also be applied to the above-described embodiment in which driving control (steering control) is performed using the target position Px (forward gaze point). For example, if the distance La from the current position Pv of the work vehicle 10 to the end position Pe of the first route is less than the threshold distance Lth1, if the angle d1 between the first route and the second route is less than the threshold angle Dth, or if the length Lb of the second route is less than the threshold length Lth2, the vehicle control device 11 decelerates the vehicle speed of the work vehicle 10, and when the vehicle speed is decelerated, switches from driving control using the target position Px to driving control using the deviation t1. In other words, the vehicle control device 11 executes driving control using the target position Px while the work vehicle 10 is traveling at a set vehicle speed (vehicle speed for straight-ahead traveling), and executes driving control using the deviation t1 while the work vehicle 10 is traveling at a vehicle speed slower than the set vehicle speed. This further improves driving accuracy during low-speed traveling.

[0118] In each of the above-described embodiments, the first route and the second route are both straight routes. However, in other embodiments, at least one of the first route and the second route may be a curved route. For example, as shown in FIG. 14, the first route may be a straight route r51, and the second route may be a curved route r52. In this case, the vehicle control device 11 sets the target position Px based on the angle d1 formed between the straight route r51 on which the work vehicle 10 is traveling and the next curved route r52, and the distance La from the current position Pv of the work vehicle 10 to the end position Pe of the straight route r51 (the start position P1 of the curved route r52). Furthermore, when the work vehicle 10 travels on the curved route r52 (corresponding to the first route), the vehicle control device 11 sets the target position Px based on the angle d2 formed between the curved route r52 and the next curved route r53 (corresponding to the second route) and the distance from the current position Pv to the end position Pe of the curved route r52 (the start position P2 of the curved route r53).

[0119] In the above-described embodiments, the automatic driving system 1 corresponds to the automatic driving system according to the present invention, but the automatic driving system according to the present invention may also be configured by the work vehicle 10 alone.

[0120] [Notes on the Invention] The following will provide an outline of the invention extracted from the above-described embodiments. Note that the configurations and processing functions described in the following supplementary notes can be selected and combined as desired.

[0121] <Appendix 1> An automatic driving method for automatically driving a work vehicle along a target route including a straight route and a turning route, setting a target position at a predetermined position a predetermined distance away from the current position in the traveling direction based on an angle between a first route on which the work vehicle is traveling and a second route that continues on the first route, and a distance from the current position of the work vehicle to an end position of the first route; causing the work vehicle to travel so as to follow the target position; An automated driving method that performs the above.

[0122] <Appendix 2> When the distance is less than a threshold distance, when the formed angle is less than a threshold angle, or when the length of the second path is less than a threshold length, the speed of the work vehicle is reduced. 1. The automated driving method according to claim 1.

[0123] <Appendix 3> accepting a user operation to set in advance whether to enable or disable a process for slowing down the speed of the work vehicle when the distance is less than the threshold distance; When the process is set to disabled, the speed of the work vehicle is reduced when the formed angle is less than a threshold angle or when the length of the second route is less than a threshold length. 2. The automated driving method according to claim 2.

[0124] <Appendix 4> The larger the angle, the longer the predetermined distance is set, and the smaller the angle, the shorter the predetermined distance is set. 4. The automatic driving method according to any one of appendices 1 to 3.

[0125] <Appendix 5> When the distance is less than the predetermined distance, the target position is set on an extension of the first path or on the second path. 5. The automatic driving method according to any one of appendices 1 to 4.

[0126] <Appendix 6> When the target position is set on the second route, the target position is moved on the second route so that the sum of the distance and the distance from the terminal position to the target position does not change as the work vehicle travels. 1. The automated driving method according to claim 5.

[0127] <Appendix 7> When the distance reaches the predetermined distance, the target position is set on the second path. 7. The automated driving method according to claim 5 or 6.

[0128] <Appendix 8> If the distance is less than the predetermined distance, the target position is set on the second path; As the distance becomes shorter, the predetermined distance is increased. An automatic driving method according to any one of appendices 5 to 7.

[0129] <Appendix 9> If the distance is less than the predetermined distance, the target position is set on the extension line; When the current position of the work vehicle reaches the terminal position, the target position is set on the second route. An automatic driving method according to any one of appendices 5 to 8.

[0130] <Appendix 10> When the vehicle speed of the work vehicle is reduced, the steering angle of the work vehicle is controlled based on the length of the second route and the lateral deviation from the current position of the work vehicle to the first route. An automatic driving method according to any one of appendices 1 to 9.

[0131] <Appendix 11> The turning path is made up of a plurality of consecutive straight path paths, the second path is included in the plurality of linear paths; An automatic driving method according to any one of appendices 1 to 10.

[0132] <Appendix 12> An automatic driving method for automatically driving a work vehicle along a target route including a straight route and a turning route, An automatic driving method that controls the steering angle of the work vehicle based on the length of a second route that follows a first route on which the work vehicle is traveling and the lateral deviation from the current position of the work vehicle to the first route. [Explanation of symbols]

[0133] 1:Automated driving system 10: Work vehicle 20: Operation terminal 11: Vehicle control device 111: Driving processing unit 112: Setting processing section 113: Vehicle speed control processing unit 211: Registration processing unit 212: Setting processing section 213: Generation processing unit 214: Output processing section F: Field R1: Target route Px:Target position Pv:Current position r1: Straight route (first route) r2: Turning path (second path) r21: Partial straight line path (second path) r51: Straight path (first path) r52: Curved route (second route) d1: angle Dth: Threshold angle L1: Predetermined distance Lth1: Threshold distance P1: Starting position Pe: End position t1: deviation

Claims

1. An automatic driving method for automatically driving a work vehicle along a target route including a straight route and a turning route, setting a target position at a predetermined position a predetermined distance away from the current position in the traveling direction of the work vehicle based on an angle formed between a first route on which the work vehicle is traveling and a second route that continues on the first route, and a distance from the current position of the work vehicle to an end position of the first route; causing the work vehicle to travel so as to follow the target position; An automated driving method that performs the above.

2. When the distance is less than a threshold distance, when the formed angle is less than a threshold angle, or when the length of the second path is less than a threshold length, the speed of the work vehicle is reduced. The automatic driving method according to claim 1 .

3. accepting a user operation to set in advance whether to enable or disable a process for slowing down the speed of the work vehicle when the distance is less than the threshold distance; When the process is set to disabled, the speed of the work vehicle is reduced when the formed angle is less than a threshold angle or when the length of the second route is less than a threshold length. The automatic driving method according to claim 2.

4. The larger the angle, the longer the predetermined distance is set, and the smaller the angle, the shorter the predetermined distance is set. The automatic driving method according to claim 1 .

5. When the distance is less than the predetermined distance, the target position is set on an extension of the first path or on the second path. The automatic driving method according to claim 1 .

6. When the target position is set on the second route, the target position is moved on the second route so that the sum of the distance and the distance from the end position to the target position does not change as the work vehicle travels. The automatic driving method according to claim 5.

7. When the distance reaches the predetermined distance, the target position is set on the second route. The automatic driving method according to claim 5.

8. If the distance is less than the predetermined distance, the target position is set on the second path; As the distance becomes shorter, the predetermined distance is increased. The automatic driving method according to claim 5.

9. If the distance is less than the predetermined distance, the target position is set on the extension line; When the current position of the work vehicle reaches the terminal position, the target position is set on the second route. The automatic driving method according to claim 5.

10. When the vehicle speed of the work vehicle is reduced, the steering angle of the work vehicle is controlled based on the length of the second route and the lateral deviation from the current position of the work vehicle to the first route. The automatic driving method according to claim 1 .

11. The turning path is made up of a plurality of consecutive straight path paths, the second path is included in the plurality of linear paths; The automatic driving method according to any one of claims 1 to 10.

12. An automatic driving method for automatically driving a work vehicle along a target route including a straight route and a turning route, An automatic driving method that controls the steering angle of the work vehicle based on the length of a second route that follows a first route on which the work vehicle is traveling and the lateral deviation from the current position of the work vehicle to the first route.

13. An automatic driving program that automatically drives a work vehicle along a target route including a straight route and a turning route, setting a target position at a predetermined position a predetermined distance away from the current position in the traveling direction of the work vehicle based on an angle formed between a first route on which the work vehicle is traveling and a second route that continues on the first route, and a distance from the current position of the work vehicle to an end position of the first route; causing the work vehicle to travel so as to follow the target position; An automated driving program for executing the above on one or more processors.

14. An automated driving system that automatically drives a work vehicle along a target route including a straight route and a turning route, a setting processing unit that sets a target position at a predetermined position a predetermined distance away from the current position in the traveling direction of the work vehicle based on an angle between a first route on which the work vehicle is traveling and a second route that follows the first route, and a distance from the current position of the work vehicle to an end position of the first route; a travel processing unit that causes the work vehicle to travel so as to follow the target position; An autonomous driving system equipped with

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