JP7507113B2 - Work vehicle and work vehicle control system - Google Patents

Description

This disclosure relates to a work vehicle and a control system for the work vehicle.

Research and development is underway to automate work vehicles such as tractors used in farm fields. For example, work vehicles that run with automatic steering using positioning systems such as the Global Navigation Satellite System (GNSS), which allows precise positioning, have been put to practical use. Work vehicles that automatically control speed in addition to automatic steering have also been put to practical use. For example, Patent Documents 1 to 6 disclose examples of work vehicles that run automatically in farm fields.

Patent Document 1 discloses an example of a work vehicle that can turn smoothly during automatic driving. The work vehicle disclosed in Patent Document 1 sets a deceleration point before the turning start point, and if the gear shift is faster than a specified gear shift at the deceleration point, it switches to the specified gear shift and decelerates. It is described that this enables smooth and safe turning.

Patent Document 2 discloses an automatic driving system for a work vehicle. The automatic driving system of Patent Document 2 limits the speed of the work vehicle according to the distance from the work vehicle to the outer edge of the work site in the direction of travel of the work vehicle when the work vehicle is automatically driving along one of multiple parallel paths. In other words, the work vehicle slows down as it approaches the outer edge of the work site. It is described that this makes it possible to prevent the work vehicle from going out of the field and coming into contact with other objects such as ridges when the work vehicle is stopped near the outer edge of the field or turned along a turning path.

Patent Document 3 discloses a work vehicle that properly recognizes when it has reached a ridge area (or headland) and performs appropriate direction changes. The work vehicle disclosed in Patent Document 3 detects that the work vehicle has approached or reached a ridge area based on the position of the vehicle or work equipment measured by a positioning unit while traveling. It is described that this makes it possible to automatically change direction in the ridge area and to notify the driver of its approach to the ridge area.

Patent Document 4 discloses a driving assistance system that manages in a user-friendly manner the work driving sequences that are performed in the transition region from straight driving to headland turning, and in the transition region from headland turning to the next straight driving. This driving assistance system displays on the display buttons for selecting a work driving sequence, and a group of icons showing the contents of the selected work driving sequence.

Patent document 5 discloses an example of a work vehicle equipped with a headland management system (HMS) that executes a headland turn sequence (HTS) at a predetermined position in a field. The HMS causes a display to show a real-time map including the vehicle's position and at least some events of the HTS that will be executed later. The operator can modify at least one event of the HTS displayed on the real-time map. For example, the operator can add and delete HTS events, and change the position where the HTS events are executed.

Patent Document 6 discloses a guidance system for a work vehicle. The guidance system includes a control system. The control system determines a turning path at the end of the row on which the work vehicle is traveling based on the relative position of the work vehicle with respect to the work area and the minimum turning radius of the work vehicle, and causes the work vehicle to perform the turn.

JP 2019-187358 A JP 2020-028243 A JP 2020-058384 A JP 2020-168002 A International Publication No. 2016/131684 US Patent Publication No. 2020/0296878

This disclosure provides a work vehicle and its control system that can perform turns more smoothly using automatic steering.

A control system according to yet another exemplary embodiment of the present disclosure is a control system for a work vehicle that performs automatic steering operation. The control system includes a storage device that stores a target route for the work vehicle, and a control device that can switch between an automatic steering mode and a manual steering mode, and that controls the steering of the work vehicle in the automatic steering mode so that the work vehicle travels along the target route based on the position of the work vehicle identified by a positioning device and the target route stored in the storage device. The target route includes a plurality of parallel main routes and one or more turning routes connecting the plurality of main routes. In the automatic steering mode, when the work vehicle travels along one of the plurality of main routes and reaches the start point of a turning route connected to the main route or a point a predetermined distance before the start point, if the speed of the work vehicle exceeds a threshold value, the control device cancels the automatic steering mode and switches to the manual steering mode, and if the speed of the work vehicle does not exceed the threshold value, the control device continues the automatic steering mode and controls the steering of the work vehicle so that the work vehicle turns along the turning route.

The general or specific aspects of the present disclosure may be realized by an apparatus, a system, a method, an integrated circuit, a computer program, or a computer-readable non-transitory storage medium, or any combination thereof. The computer-readable storage medium may include a volatile storage medium or a non-volatile storage medium. The apparatus may be composed of multiple devices. When the apparatus is composed of two or more devices, the two or more devices may be arranged in one device or may be arranged separately in two or more separate devices.

Embodiments of the present disclosure enable work vehicles to more smoothly perform turns using automatic steering.

1 is a perspective view showing an example of the appearance of a work vehicle in a first embodiment. FIG. 1 is a side view showing a schematic diagram of an example of a work vehicle and a work implement coupled to the work vehicle; 1 is a block diagram showing an example of a schematic configuration of a work vehicle and a work machine. FIG. 1 is a conceptual diagram showing an example of a work vehicle performing positioning using RTK-GNSS. 4 is a schematic diagram showing an example of an operation terminal and an operation switch group provided inside the cabin. FIG. FIG. 11 is a diagram illustrating an example of the traveling of a work vehicle in an automatic steering mode. 1 is a diagram showing a schematic example of a target route of a work vehicle traveling in a farm field using automatic steering; FIG. 11 is a first diagram for explaining the flow of an operation for recording a target path and an operation sequence. FIG. 2 is a second diagram for explaining the flow of operations for recording a target path and an operation sequence. FIG. 3 is a third diagram for explaining the flow of operations for recording a target path and an operation sequence. FIG. 4 is a fourth diagram for explaining the flow of operations for recording a target path and an operation sequence. FIG. 5 is a fifth diagram for explaining the operational flow of recording a target path and an operation sequence. FIG. 6 is a sixth diagram for explaining the operational flow of recording a target path and an operation sequence. 4 is a flowchart showing an example of an operation during automatic steering executed by the control device. FIG. 2 is a diagram illustrating an example of a work vehicle traveling along a target route. FIG. 13 is a diagram showing an example of a work vehicle in a position shifted to the right from the target route. FIG. 13 is a diagram showing an example of a work vehicle in a position shifted to the left from a target route. FIG. 13 is a diagram showing an example of a work vehicle facing in an inclined direction with respect to a target route. FIG. 13 is a diagram showing an example of a setting screen related to route deviation notification. FIG. 13 is a diagram showing another example of a setting screen relating to route deviation notification. 13 is a flowchart showing an example of an operation for outputting two warnings when a route deviates; 13 is a flowchart showing another example of the operation of outputting two warnings when a route deviates; FIG. 13 is a diagram showing an example of a pop-up notification displayed when a route deviates. 13 is a diagram showing an example of a display screen in a state in which the work vehicle is correctly positioned on a target route by the user's driving after switching to manual steering mode. FIG. 1A and 1B are diagrams illustrating an example of deviation from a target path that may occur when a work vehicle turns at high speed. 1A and 1B are diagrams illustrating examples of deviations from a target route that may occur when a work vehicle travels at high speed along a main route that includes a sharp curve within a work area. FIG. 13 is a diagram illustrating an example of a calculation position of a radius of curvature. FIG. 11 is a diagram illustrating an example of a method for calculating a radius of curvature. 10 is a flowchart showing a first example of an operation for limiting the speed of a work vehicle in accordance with a radius of curvature. 10 is a flowchart showing a second example of the operation of limiting the speed of a work vehicle depending on the radius of curvature. 11 is a graph showing a first example of a function indicating the relationship between the radius of curvature and the speed limit. 13 is a graph showing a second example of a function showing the relationship between the radius of curvature and the speed limit. 13 is a graph showing a third example of a function showing the relationship between the radius of curvature and the speed limit. 13 is a graph showing a fourth example of a function showing the relationship between the radius of curvature and the speed limit. 10 is a flowchart showing an example of an operation for limiting the speed of a work vehicle in accordance with a time rate of change of a radius of curvature. 11 is a graph showing a first example of a function indicating the relationship between the absolute value of the time rate of change of the radius of curvature and the speed limit. 13 is a graph showing a second example of a function indicating the relationship between the absolute value of the time rate of change of the radius of curvature and the speed limit. 13 is a graph showing a third example of a function indicating the relationship between the absolute value of the time rate of change of the radius of curvature and the speed limit. FIG. 11 is a diagram for explaining an example of the timing of deceleration during turning. FIG. 13 is a diagram showing an example of a pop-up notification indicating that a work vehicle is approaching a turning path. 13A to 13C are diagrams illustrating an example of the operation of a work vehicle in the third embodiment. 11 is a diagram showing an example of a screen displayed on a display device when a work vehicle is traveling with automatic steering along a straight main route. FIG. FIG. 13 is a diagram showing an example of a pop-up screen that is displayed when a user instructs on-demand turning. FIG. 13 is a diagram showing an example of a screen for configuring settings related to semi-automatic driving. FIG. 13 is a diagram showing an example of a screen for making settings related to semi-automatic driving on a headland. 11 is a diagram showing an example of a route created by a control device when an instruction for on-demand turning is issued by a user. FIG. FIG. 13 is a diagram showing an example of a corrected route. FIG. 13 is a diagram showing an example of a pop-up that is displayed when a route that overlaps with already cultivated land is created during on-demand turning. FIG. 13 is a diagram showing an example of a display screen when changing the route of an on-demand turning operation. 13 is a diagram for explaining the operation of the work vehicle of the fourth embodiment. FIG. 11 is a graph showing a first example of a function indicating the correspondence relationship between the curvature of a turning path and a distance d2. 13 is a graph showing a second example of a function indicating the correspondence relationship between the curvature of a turning path and a distance d2. 13 is a graph showing a third example of a function indicating the correspondence relationship between the speed of the work vehicle and the distance d2. 13 is a graph showing a first example of a function indicating the correspondence relationship between the speed of the work vehicle and a distance d2. 13 is a graph showing a second example of a function indicating the correspondence relationship between the speed of the work vehicle and the distance d2. 13 is a graph showing a third example of a function indicating the correspondence relationship between the speed of the work vehicle and the distance d2. 11 is a graph showing a first example of a function indicating a correspondence relationship between a curvature of a turning path and a speed threshold value. 13 is a graph showing a second example of a function indicating the correspondence relationship between the curvature of a turning path and a speed threshold value. 13 is a graph showing a third example of a function indicating the correspondence relationship between the curvature of a turning path and a speed threshold value. 13 is a flowchart showing an example of the operation of a control device in embodiment 4. FIG. 13 is a diagram illustrating an example of a pop-up notification indicating a switch from automatic steering mode to manual steering mode.

Below, an embodiment of the present disclosure will be described. However, more detailed explanation than necessary may be omitted. For example, detailed explanation of already well-known matters and duplicate explanation of substantially the same configuration may be omitted. This is to avoid the following explanation becoming unnecessarily redundant and to facilitate understanding by those skilled in the art. Note that the inventor provides the attached drawings and the following explanation to enable those skilled in the art to fully understand the present disclosure, and does not intend for them to limit the subject matter described in the claims. In the following explanation, components having the same or similar functions are given the same reference symbols.

The following embodiments are illustrative, and the technology of the present disclosure is not limited to the following embodiments. For example, the numerical values, shapes, materials, steps, the order of the steps, the layout of the display screen, and the like shown in the following embodiments are merely examples, and various modifications are possible as long as no technical contradictions arise. In addition, one aspect can be combined with another aspect as long as no technical contradictions arise.

Below, an embodiment in which the technology of the present disclosure is applied to a tractor, which is an example of a work vehicle, is described. The technology of the present disclosure can be applied not only to tractors, but also to any work vehicle that runs with automatic steering. The work vehicle may be, for example, a rice transplanter, a combine harvester, a grass cutter, a harvester, a snowplow, or a construction vehicle.

(Embodiment 1)
A work vehicle and a control system for the work vehicle in a first exemplary embodiment of the present disclosure will be described.

The work vehicle in this embodiment is equipped with a control system that performs control to realize automatic steering operation. The control system is a computer system equipped with a storage device and a control device. The storage device includes one or more storage media and stores various data such as the target route of the work vehicle. The control device includes one or more processors or control circuits and controls the operation of the work vehicle. The control device controls the steering of the work vehicle so that the work vehicle travels along the target route based on the position of the work vehicle identified by the positioning device and the target route stored in the storage device. The positioning device is disposed inside or outside the work vehicle. The positioning device includes, for example, a GNSS receiver and identifies the position of the work vehicle based on signals from GNSS satellites. The positioning device may include devices other than the GNSS receiver, such as a LiDAR sensor or a camera. The position of the work vehicle can be estimated by matching the data acquired by the LiDAR sensor or the camera with a previously prepared environmental map. The target route is a route that is a target for travel set in the environment in which the work vehicle travels. The target route is set before starting automatic steering operation and recorded in the storage device. The target route includes multiple parallel main routes and one or more turning routes that connect the multiple main routes. The control device controls the steering angle of the steering wheels (e.g., the front wheels) of the work vehicle so that the work vehicle travels back and forth within the field along the target route.

The main route is set within a work area, for example, within a farm field, where the work vehicle performs plowing, mowing, sowing, fertilizing, pest control, and other tasks. The main route may be a straight route or a route that includes curved portions. The turning route may be set, for example, in a headland located near the outer edge of the farm field.

If the work vehicle deviates from the target turning path when turning in the headland using automatic steering, it may take time to return to the target path after the turn, and in some cases the work vehicle may end up going outside the field. If a deviation from the path occurs, it is important to notify the user promptly.

One possible method for notifying the user that the work vehicle has deviated from the target route is to display the deviation (distance) between the work vehicle's position and the target route on a display device (display) of an operation terminal installed on the work vehicle while the vehicle is traveling using automatic steering. However, simply displaying the deviation on a display device may take time for the user to notice the deviation from the route.

In this embodiment, when the work vehicle is turning along the turning path by automatic steering, if the position of the work vehicle is away from the turning path by a reference distance or more, the warning device outputs a warning. The warning device may include, for example, an audio output device such as a buzzer or speaker and/or a display device. The warning may be issued by a method that strongly stimulates the user's five senses, such as a loud sound, a strong light, or vibration. This allows the user to be notified of the situation early when the work vehicle deviates from the target path during turning by automatic steering. As a result, the user can operate the device to avoid deviation before the work vehicle deviates significantly from the target path. The reference distance is set to an appropriate value according to the work accuracy required by the user. The above operation allows the user to notice at an early stage when the work accuracy required by the user is not being met.

<Configuration>
Fig. 1 is a perspective view showing an example of the appearance of a work vehicle 100 in this embodiment. Fig. 2 is a side view showing a schematic example of the work vehicle 100 and a work implement 300 coupled to the work vehicle 100. The work vehicle in this embodiment is a tractor used in farm fields. The techniques in this embodiment and other embodiments described below can also be applied to work vehicles other than tractors, unless there is a contradiction.

In this embodiment, the work vehicle 100 is equipped with a positioning device 120 and one or more obstacle sensors 130. Although one obstacle sensor 130 is illustrated in FIG. 1, the obstacle sensor 130 may be provided at multiple locations on the work vehicle 100.

As shown in FIG. 2, the work vehicle 100 includes a vehicle body 101, a prime mover (engine) 102, and a transmission 103. The vehicle body 101 is provided with tires 104 (wheels) and a cabin 105. The tires 104 include a pair of front wheels 104F and a pair of rear wheels 104R. Inside the cabin 105, a driver's seat 107, a steering device 106, an operation terminal 200, and a group of switches for operation are provided. One or both of the front wheels 104F and the rear wheels 104R may be crawlers instead of tires. The work vehicle 100 may be a four-wheel drive vehicle equipped with four tires 104 as drive wheels, or may be a two-wheel drive vehicle equipped with a pair of front wheels 104F or a pair of rear wheels 104R as drive wheels. In the following description, it is assumed that the work vehicle 100 can switch between a two-wheel drive (2W) mode and a four-wheel drive (4W) mode.

The positioning device 120 in this embodiment includes a GNSS receiver. The GNSS receiver includes an antenna that receives signals from GNSS satellites and a processing circuit that determines the position of the work vehicle 100 based on the signals received by the antenna. The positioning device 120 receives GNSS signals transmitted from the GNSS satellites and performs positioning based on the GNSS signals. GNSS is a general term for satellite positioning systems such as GPS (Global Positioning System), QZSS (Quasi-Zenith Satellite System, e.g., Michibiki), GLONASS, Galileo, and BeiDou. The positioning device 120 in this embodiment is provided on the top of the cabin 105, but may be provided in another location.

The positioning device 120 may include other types of devices such as a LiDAR sensor or a camera (including an image sensor) instead of or in addition to the GNSS receiver. If there is a feature functioning as a feature point in the environment in which the work vehicle 100 travels, the position of the work vehicle 100 can be estimated with high accuracy based on the data acquired by the LiDAR sensor or camera and the environmental map previously recorded in the storage device 170. The LiDAR sensor 110 or the camera may be used in combination with a GNSS receiver. The position of the work vehicle 100 can be specified with higher accuracy by correcting or complementing the position data based on the GNSS signal using the data acquired by the LiDAR sensor 110 or the camera. The positioning device 120 can further complement the position data using a signal from an inertial measurement unit (IMU). The IMU can measure the tilt and minute movement of the work vehicle 100. Positioning performance can be improved by complementing position data based on GNSS signals with data acquired by the IMU.

1 and 2, an obstacle sensor 130 is provided at the rear of the vehicle body 101. The obstacle sensor 130 may be provided at a location other than the rear of the vehicle body 101. For example, one or more obstacle sensors 130 may be provided at any of the sides, front, and cabin 105 of the vehicle body 101. The obstacle sensor 130 detects objects present around the work vehicle 100. The obstacle sensor 130 may include, for example, a laser scanner or an ultrasonic sonar. When an object is present closer than a predetermined distance from the obstacle sensor 130, the obstacle sensor 130 outputs a signal indicating the presence of an obstacle. Multiple obstacle sensors 130 may be provided at different positions on the body of the work vehicle 100. For example, multiple laser scanners and multiple ultrasonic sonars may be provided at different positions on the body. By providing such a large number of obstacle sensors 130, blind spots in monitoring obstacles around the work vehicle 100 can be reduced.

The prime mover 102 is, for example, a diesel engine. An electric motor may be used instead of a diesel engine. The transmission 103 can change the propulsive force and travel speed of the work vehicle 100 by changing gears. The transmission 103 can also switch the work vehicle 100 between forward and reverse.

The steering device 106 includes a steering wheel, a steering shaft connected to the steering wheel, and a power steering device that assists steering by the steering wheel. The front wheels 104F are steered wheels, and the traveling direction of the work vehicle 100 can be changed by changing the turning angle (also called the "steering angle"). The steering angle of the front wheels 104F can be changed by operating the steering wheel. The power steering device includes a hydraulic device or an electric motor that supplies an auxiliary force to change the steering angle of the front wheels 104F. When automatic steering is performed, the steering angle is automatically adjusted by the force of the hydraulic device or the electric motor under the control of a control device arranged in the work vehicle 100.

A coupling device 108 is provided at the rear of the vehicle body 101. The coupling device 108 includes, for example, a three-point support device (also called a "three-point link" or "three-point hitch"), a PTO (Power Take Off) shaft, a universal joint, and a communication cable. The coupling device 108 can attach and detach the working machine 300 to the work vehicle 100. The coupling device 108 can raise and lower the three-point link using, for example, a hydraulic device, to control the position or attitude of the working machine 300. In addition, power can be sent from the work vehicle 100 to the working machine 300 via the universal joint. The work vehicle 100 can make the working machine 300 perform a predetermined task while pulling the working machine 300. The coupling device may be provided at the front of the vehicle body 101. In that case, the working machine can be connected to the front of the work vehicle 100.

The working machine 300 shown in FIG. 2 is a rotary tiller, but the working machine 300 is not limited to a rotary tiller. For example, any working machine, such as a mower, a seeder, a spreader, a rake, a baler, a harvester, a sprayer, or a harrow, can be connected to the work vehicle 100 and used.

Figure 3 is a block diagram showing an example of a schematic configuration of the work vehicle 100 and the work machine 300. The work vehicle 100 and the work machine 300 can communicate with each other via a communication cable included in the coupling device 108.

In the example of FIG. 3, the work vehicle 100 includes a positioning device 120, an obstacle sensor 130, an operation terminal 200, a drive unit 140, a steering wheel sensor 150, a turning angle sensor 152, a control system 160, a communication interface (IF) 190, an operation switch group 210, and a buzzer 220. The positioning device 120 includes a GNSS receiver 121, an RTK receiver 122, and an inertial measurement unit (IMU) 125. The control system 160 includes a storage device 170 and a control device 180. The control device 180 includes multiple electronic control units (ECUs) 181 to 186. The work machine 300 includes a drive unit 340, a control device 380, and a communication interface (IF) 390. Note that FIG. 3 shows components that are relatively highly related to the automatic steering or automatic driving operation of the work vehicle 100, and the illustration of other components is omitted.

The positioning device 120 shown in FIG. 3 uses RTK (Real Time Kinematic)-GNSS to perform positioning of the work vehicle 100. FIG. 4 is a conceptual diagram showing an example of a work vehicle 100 performing positioning using RTK-GNSS. In positioning using RTK-GNSS, in addition to GNSS signals transmitted from multiple GNSS satellites 50, a correction signal transmitted from a reference station 60 is used. The reference station 60 may be installed around the field in which the work vehicle 100 runs (for example, within 10 km of the work vehicle 100). The reference station 60 generates a correction signal based on the GNSS signals received from the multiple GNSS satellites 50 and transmits it to the positioning device 120. The GNSS receiver 121 in the positioning device 120 receives the GNSS signals transmitted from the multiple GNSS satellites 50. The RTK receiver 122 in the positioning device 120 receives the correction signal transmitted from the reference station 60. The positioning device 120 performs positioning by calculating the position of the work vehicle 100 based on the GNSS signal and the correction signal. By using RTK-GNSS, it is possible to perform positioning with an accuracy of, for example, a few centimeters. Position information including latitude, longitude, and altitude information is obtained by high-precision positioning using RTK-GNSS. The positioning device 120 calculates the position of the work vehicle 100 at a frequency of, for example, about 1 to 10 times per second.

The positioning method is not limited to RTK-GNSS, and any positioning method (such as interferometric positioning or relative positioning) that can obtain position information with the required accuracy can be used. For example, positioning may be performed using a Virtual Reference Station (VRS) or a Differential Global Positioning System (DGPS). Furthermore, if position information with the required accuracy can be obtained without using a correction signal transmitted from the reference station 60, the position information may be generated without using a correction signal. In that case, the positioning device 120 does not need to be equipped with an RTK receiver 122.

The positioning device 120 in this embodiment further includes an IMU 125. The IMU 125 includes a three-axis acceleration sensor and a three-axis gyroscope. The IMU 125 may include a direction sensor such as a three-axis geomagnetic sensor. The IMU 125 functions as a motion sensor and can output signals indicating various quantities such as the acceleration, speed, displacement, and attitude of the work vehicle 100. The positioning device 120 can estimate the position and orientation of the work vehicle 100 with higher accuracy based on the signal output from the IMU 125 in addition to the GNSS signal and the correction signal. The signal output from the IMU 125 can be used to correct or complement the position calculated based on the GNSS signal and the correction signal. The IMU 125 outputs a signal at a higher frequency than the GNSS signal. Using the high-frequency signal, the position and orientation of the work vehicle 100 can be measured at a higher frequency (e.g., 10 Hz or more). Instead of the IMU 125, a three-axis acceleration sensor and a three-axis gyroscope may be provided separately. The IMU 125 may be provided as a device separate from the positioning device 120.

The positioning device 120 may include other types of sensors, such as a LiDAR sensor or an image sensor, in addition to or instead of the GNSS receiver 121, the RTK receiver 122, and the IMU 125. Depending on the environment in which the work vehicle 100 travels, the position and orientation of the work vehicle 100 can be estimated with high accuracy based on data from these sensors.

The drive device 140 includes various devices necessary for the travel of the work vehicle 100 and the driving of the work equipment 300, such as the aforementioned prime mover 102, the transmission 103, the differential including a differential lock mechanism, the steering device 106, and the coupling device 108. The prime mover 102 includes an internal combustion engine such as a diesel engine. The drive device 140 may include an electric motor for traction instead of or in addition to the internal combustion engine.

The steering wheel sensor 150 measures the rotation angle of the steering wheel of the work vehicle 100. The turning angle sensor 152 measures the turning angle of the front wheels 104F, which are the steered wheels. The measurements by the steering wheel sensor 150 and the turning angle sensor 152 are used for steering control by the control device 180.

The storage device 170 includes one or more storage media, such as a flash memory or a magnetic disk. The storage device 170 stores various data generated by each sensor and the control device 180. The data stored in the storage device 170 may include map data of the environment in which the work vehicle 100 travels, and data on a target route for automatic steering. The storage device 170 also stores computer programs that cause each ECU in the control device 180 to execute various operations described below. Such computer programs may be provided to the work vehicle 100 via a storage medium (e.g., a semiconductor memory or an optical disk) or an electric communication line (e.g., the Internet). Such computer programs may be sold as commercial software.

The control device 180 includes a plurality of ECUs. The plurality of ECUs include an ECU 181 for speed control, an ECU 182 for steering control, an ECU 183 for automatic steering control, an ECU 184 for work machine control, an ECU 185 for display control, and an ECU 186 for buzzer control. The ECU 181 controls the speed of the work vehicle 100 by controlling the prime mover 102, the transmission 103, and the brakes included in the drive device 140. The ECU 182 controls the steering of the work vehicle 100 by controlling the hydraulic device or the electric motor included in the steering device 106 based on the measurement value of the steering wheel sensor 150. The ECU 183 performs calculations and control to realize automatic steering operation based on signals output from the positioning device 120, the steering wheel sensor 150, and the turning angle sensor 152. During automatic steering operation, the ECU 183 sends a command to the ECU 182 to change the steering angle. The ECU 182 changes the steering angle by controlling the steering device 106 in response to the command. The ECU 184 controls the operation of the coupling device 108 to cause the work machine 300 to perform the desired operation. The ECU 184 also generates a signal to control the operation of the work machine 300 and transmits the signal from the communication IF 190 to the work machine 300. The ECU 185 controls the display of the operation terminal 200. For example, the ECU 185 realizes various displays on the display device of the operation terminal 200, such as a map of the field, the position and target route of the work vehicle 100 on the map, pop-up notifications, and setting screens. The ECU 186 controls the output of a warning sound by the buzzer 220.

Through the operation of these ECUs, the control device 180 realizes driving by manual steering or automatic steering. During automatic steering driving, the control device 180 controls the drive device 140 based on the position of the work vehicle 100 measured or estimated by the positioning device 120 and the target route stored in the storage device 170. In this way, the control device 180 causes the work vehicle 100 to travel along the target route. The control device 180 also has a function of automatically driving the work vehicle 100 at a reference speed set by the user. This function is called an auto cruise control function or simply a cruise control function. The cruise control function is realized by the operation of the ECU 181.

The multiple ECUs included in the control device 180 can communicate with each other according to a vehicle bus standard such as CAN (Controller Area Network). In FIG. 3, each of the ECUs 181 to 186 is shown as an individual block, but the functions of each of these may be realized by multiple ECUs. Also, an on-board computer that integrates at least some of the functions of the ECUs 181 to 186 may be provided. The control device 180 may include ECUs other than the ECUs 181 to 186, and any number of ECUs may be provided depending on the functions. Each ECU has a control circuit including one or more processors.

The communication IF 190 is a circuit that communicates with the communication IF 390 of the working machine 300. The communication IF 190 transmits and receives signals that conform to the ISOBUS standard, such as ISOBUS-TIM, between the communication IF 390 of the working machine 300. This makes it possible to cause the working machine 300 to perform a desired operation and to obtain information from the working machine 300. The communication IF 190 may communicate with an external computer via a wired or wireless network. The external computer may be, for example, a server computer in an agricultural management support system that centrally manages information about fields on the cloud and supports agriculture by utilizing the data on the cloud.

The operation terminal 200 is a terminal through which the user performs operations related to the traveling of the work vehicle 100 and the operation of the work equipment 300, and is also called a virtual terminal (VT). The operation terminal 200 may have a display device such as a touch screen, and/or one or more buttons. By operating the operation terminal 200, the user can perform various operations such as switching the automatic steering mode on/off, switching the cruise control on/off, setting the initial position of the work vehicle 100, setting a target route, recording or editing a map, switching between 2WD/4WD, switching the differential lock on/off, and switching the work equipment 300 on/off. At least some of these operations can also be realized by operating the operation switch group 210. The display on the operation terminal 200 is controlled by the ECU 185.

The buzzer 220 is an audio output device that emits a warning sound to notify the user of an abnormality. For example, the buzzer 220 emits a warning sound when the work vehicle 100 deviates from the target route by a predetermined distance or more during automatic steering operation. Instead of the buzzer 220, a similar function may be realized by the speaker of the operation terminal 200. The buzzer 220 is controlled by the ECU 186.

The drive unit 340 in the work machine 300 performs the operations required for the work machine 300 to perform a specified task. The drive unit 340 includes devices according to the application of the work machine 300, such as a hydraulic device, an electric motor, or a pump. The control device 380 controls the operation of the drive unit 340. The control device 380 causes the drive unit 340 to perform various operations in response to signals transmitted from the work vehicle 100 via the communication IF 390. In addition, signals according to the state of the work machine 300 can also be transmitted from the communication IF 390 to the work vehicle 100.

Figure 5 is a diagram showing an example of an operation terminal 200 and an operation switch group 210 provided inside the cabin 105. Inside the cabin 105, a switch group 210 including a plurality of switches that can be operated by the user is arranged. The switch group 210 may include, for example, a switch for selecting a main or sub-transmission gear ratio, a switch for switching between an automatic steering (autosteer) mode and a manual steering (manualsteer) mode, a switch for switching between forward and reverse, a switch for raising and lowering the work machine 300, and a switch for switching on and off an auto-cruise control function that maintains a constant speed while traveling.

<Operation>
Next, the operation of the work vehicle 100 will be described. The control device 180 in this embodiment can switch between a manual steering mode and an automatic steering mode in response to the operation of the user (e.g., the driver) of the work vehicle 100. In the manual steering mode, the control device 180 controls steering by driving the power steering device in response to the operation of the steering wheel by the user. In the automatic steering mode, the control device 180 controls steering by driving the power steering device based on the position of the work vehicle 100 measured by the positioning device 120 and a pre-recorded target route. Even in the automatic steering mode, the speed is adjusted by the accelerator operation and the brake operation by the user. However, when the cruise control function is enabled, the control device 180 also performs speed control and drives the work vehicle 100 at a speed set by the user. In the automatic steering mode and when the cruise control function is enabled, the control device 180 drives the work vehicle 100 automatically without the user's operation. In this manner, the work vehicle 100 of this embodiment can automatically control only the steering, or can automatically control both the steering and the speed.

Figure 6 is a diagram showing an example of the traveling of the work vehicle 100 in the automatic steering mode. (a) of Figure 6 is a schematic diagram showing the traveling of the work vehicle 100 along the straight target route P. (b) of Figure 6 is a schematic diagram showing the traveling of the work vehicle 100 along the curved target route P. (c) of Figure 6 is a schematic diagram showing the traveling of the work vehicle 100 along the target route P including two adjacent straight routes and a curved route connecting them. The target route P is set in advance and recorded in the storage device 170. When the work vehicle 100 is traveling in the automatic steering mode, the control device 180 calculates the deviation between the position and orientation of the work vehicle 100 measured by the positioning device 120 and the target route P, and repeats the operation of controlling the steering device so as to reduce the deviation. This causes the work vehicle 100 to travel along the target route P.

Figure 7 is a diagram showing a schematic example of a target route of the work vehicle 100 traveling in a field with automatic steering. In this example, the field includes a work area 70 in which the work vehicle 100 and the work machine 300 perform work, and a headland 80 located near the outer edge of the field. Which areas on the map of the field correspond to the work area 70 and the headland 80 can be set in advance by the user using the operation terminal 200. The target route includes multiple parallel main paths P1 and multiple turning paths P2 connecting the multiple main paths P1. The main path P1 is located within the work area 70, and the turning path P2 is located in the headland 80. The dashed line in Figure 7 represents the working width of the work machine 300. The working width is set in advance and recorded in the storage device 170. The working width can be set by the user operating the operation terminal 200 and recorded in the storage device 170. Alternatively, the working width may be automatically recognized when the work machine 300 is connected to the work vehicle 100 and recorded in the storage device 170. The spacing between the multiple main paths P1 is adjusted to the working width. The target path may be determined based on the user's operation before the automatic steering operation is started.

An example of a method for setting a target route will be described. First, the user operates the operation terminal 200 to register a start point A and an end point B located at the end of the field (for example, the boundary between the headland 80 and the work area 70). For example, the user manually drives the work vehicle 100 and drives the work vehicle 100 from the start point A to the end point B. The user presses a registration button displayed on the operation terminal 200 when the work vehicle 100 is located at the start point A and the end point B. This registers the start point A and the end point B. When this operation is performed, the control device 180 determines a reference line (guidance line) P0 connecting the start point A to the end point B. The reference line P0 shown in FIG. 7 is a straight line, but it is also possible to set a curved line as the reference line. The control device 180 determines a plurality of main paths P1 arranged at equal intervals from the reference line P0 and a plurality of turning paths P2 connecting the main paths P1 based on the working width of the work machine 300 recorded in advance in the storage device 170. This determines the target route. The target route can be determined to cover the entire work area 70 in the field, for example. The target route can also be set by the user operating the operation terminal 200 without manually driving the work vehicle 100. For example, the target route can be set at the same time as the work area 70 and headland 80 are registered.

In this embodiment, not only traveling within the working area 70 but also turning on the headland 80 can be performed by automatic steering. When turning on the headland 80, the work vehicle 100 can be set to perform a series of operations recorded in advance. A program that defines this series of operations is called an "operation sequence". The operation sequence is set by the user and recorded in the storage device 170. When the work vehicle 100 turns along a turning path by automatic steering, the control device 180 causes the work vehicle 100 to perform a series of operations according to the operation sequence recorded in advance. Different operation sequences can be recorded when starting headland turning at the end of the main path P1 (at the time of field-in) and when ending headland turning and starting traveling along the next main path P1 (at the time of field-out). For example, the following operations can be recorded as the operation sequence.
- Raising/lowering the three-point linkage - Turning the PTO on/off - Turning the differential lock on/off - Switching between 4WD/2WD - Increasing/reducing engine speed - Switching the transmission

The control system 160 functions as a headland management system (HMS) that manages a series of operations executed during headland turning. The series of operations may include a first operation performed at the start of turning and a second operation performed at the end of turning. The first operation may include at least one of the following operations: raising the working machine 300 connected to the work vehicle 100, stopping the power output to the working machine 300, stopping the differential lock function of the work vehicle 100, switching from two-wheel drive mode to four-wheel drive mode, and reducing the engine speed of the work vehicle 100. The second operation may include at least one of the following operations: lowering the working machine 300, starting the power output to the working machine 300, starting the differential lock function, switching from four-wheel drive mode to two-wheel drive mode, and increasing the engine speed. The control device 180 can display a setting screen on the display device to allow the user to set the contents of the series of operations. The control device 180 stores an operation sequence based on the contents of the set series of operations in the storage device 170.

The recording of the operation sequence can also be performed together with the operation of setting the target route before starting automatic steering operation. Below, an example of the flow of operations for recording the target route and the operation sequence is described with reference to Figures 8A to 8F.

Figure 8A shows a situation in which the work vehicle 100 is traveling manually within the work area 70 of the field. At this point, the starting point A shown in Figure 7 has already been registered, and the user manually drives the work vehicle 100 toward the end point B of the reference line P0. When the work vehicle 100 reaches the end point B as shown in Figure 8B, the user operates the operation terminal 200 to register the end point B. Furthermore, in order to start turning, the user performs operations such as raising the three-point link, turning off the PTO rotation, turning off the differential lock, and reducing the engine speed, and records the series of operations by operating the operation terminal 200. After that, the user manually drives the work vehicle 100 to turn. Figure 8C shows a situation in which the work vehicle 100 finishes turning and returns to the work area 70 from the headland 80. At this time, in order to resume work, the user performs operations such as lowering the three-point link, turning on the PTO rotation, turning on the differential lock, and increasing the engine speed, and records the series of operations by operating the operation terminal 200. After that, the user operates the operation terminal 200 to switch from the manual steering mode to the automatic steering mode. Then, as shown in FIG. 8D, the work vehicle 100 starts traveling with automatic steering along the main route P1 in the target route. During traveling with automatic steering, the user can adjust the speed of the work vehicle 100 by manually operating the accelerator and brake. In addition, when the work vehicle 100 is traveling at a desired speed, the user can operate the operation terminal 200 to record the speed at that time in the storage device 170. After recording, the user can automatically travel the work vehicle 100 at the recorded speed by turning on the cruise control function. After the state of FIG. 8D, when the work vehicle reaches the headland 80 on the opposite side as shown in FIG. 8E, the control device 180 of the work vehicle 100 plays the recorded operation sequence at the time of fielding out, automatically executes the recorded series of operations, and causes the work vehicle 100 to automatically execute a headland turn. When the turn is completed, as shown in FIG. 8F, the control device 180 plays the recorded operation sequence at the time of fielding in, automatically executes the recorded series of operations, and starts automatic steering operation along the next main route P1. By repeating the same operation thereafter, the work vehicle 100 can travel back and forth in the field with automatic steering along the target route to the end of the field.

Next, we will explain an example of control during automatic steering by the control device 180.

Figure 9 is a flowchart showing an example of the operation during automatic steering performed by the control device 180. The control device 180 performs automatic steering operation by executing the operations of steps S121 to S125 shown in Figure 9 while the work vehicle 100 is traveling. The control device 180 first acquires data indicating the position of the work vehicle 100 generated by the positioning device 120 (step S121). Next, the control device 180 calculates the deviation between the position of the work vehicle 100 and the target route (step S122). The deviation represents the distance between the position of the work vehicle 100 at that time and the target route. The control device 180 determines whether the deviation of the calculated position exceeds a preset threshold value (step S123). If the deviation exceeds the threshold value, the control device 180 changes the steering angle by changing the control parameters of the steering device included in the drive device 140 so that the deviation is reduced. If the deviation does not exceed the threshold value in step S123, the operation of step S124 is omitted. In the next step S125, the control device 180 determines whether or not a command to end the operation has been received. The command to end the operation may be issued, for example, when the user uses the operation terminal 200 to instruct the automatic steering mode to be stopped, or when the work vehicle 100 reaches the destination. If the command to end the operation has not been issued, the process returns to step S121, and the same operation is performed based on the newly measured position of the work vehicle 100. The control device 180 repeats the operations of steps S121 to S125 until a command to end the operation is issued. The above operations are executed by the ECU 183 in the control device 180.

In the example shown in FIG. 9, the control device 180 controls the drive device 140 based only on the deviation between the position of the work vehicle 100 identified by the positioning device 120 and the target route, but the control may also take into account the azimuth deviation. For example, when the azimuth deviation, which is the angular difference between the orientation of the work vehicle 100 identified by the positioning device 120 and the direction of the target route, exceeds a preset threshold, the control device 180 may change the control parameter (e.g., steering angle) of the steering device of the drive device 140 in accordance with the deviation.

Below, an example of steering control by the control device 180 will be described in more detail with reference to Figures 10A to 10D.

Figure 10A is a diagram showing an example of a work vehicle 100 traveling along a target route P. Figure 10B is a diagram showing an example of a work vehicle 100 in a position shifted to the right from the target route P. Figure 10C is a diagram showing an example of a work vehicle 100 in a position shifted to the left from the target route P. Figure 10D is a diagram showing an example of a work vehicle 100 facing in an inclined direction with respect to the target route P. In these figures, the pose indicating the position and orientation of the work vehicle 100 measured by the positioning device 120 is expressed as r (x, y, θ). (x, y) are coordinates representing the position of the reference point of the work vehicle 100 in the XY coordinate system, which is a two-dimensional coordinate system fixed to the earth. In the examples shown in Figures 10A to 10D, the reference point of the work vehicle 100 is at the position where the GNSS antenna on the cabin is installed, but the position of the reference point is arbitrary. θ is an angle representing the measured orientation of the work vehicle 100. In the illustrated example, the target path P is parallel to the Y axis, but generally the target path P is not necessarily parallel to the Y axis.

As shown in FIG. 10A, if the position and orientation of the work vehicle 100 do not deviate from the target path P, the control device 180 maintains the steering angle and speed of the work vehicle 100 unchanged.

As shown in FIG. 10B, when the position of the work vehicle 100 has shifted to the right from the target path P, the control device 180 changes the steering angle by changing the rotation angle of the steering wheel included in the drive device 140 so that the traveling direction of the work vehicle 100 tilts to the left and approaches the path P. At this time, in addition to the steering angle, the speed may also be changed. The magnitude of the steering angle may be adjusted, for example, according to the magnitude of the position deviation Δx.

As shown in FIG. 10C, when the position of the work vehicle 100 has shifted to the left from the target path P, the control device 180 changes the steering angle by changing the rotation angle of the steering wheel so that the traveling direction of the work vehicle 100 tilts to the right and approaches the path P. In this case, the speed may also be changed in addition to the steering angle. The amount of change in the steering angle may be adjusted, for example, according to the magnitude of the position deviation Δx.

As shown in FIG. 10D, when the position of the work vehicle 100 is not far from the target route P but the direction is different from the direction of the target route P, the control device 180 changes the steering angle so that the azimuth deviation Δθ is reduced. In this case, the speed may also be changed in addition to the steering angle. The magnitude of the steering angle may be adjusted, for example, according to the magnitudes of the position deviation Δx and the azimuth deviation Δθ. For example, the smaller the absolute value of the position deviation Δx, the larger the amount of change in the steering angle according to the azimuth deviation Δθ may be. When the absolute value of the position deviation Δx is large, the steering angle is changed significantly to return to the route P, so the absolute value of the azimuth deviation Δθ inevitably becomes large. Conversely, when the absolute value of the position deviation Δx is small, it is necessary to bring the azimuth deviation Δθ closer to zero. For this reason, it is appropriate to relatively increase the weight of the azimuth deviation Δθ (i.e., the control gain) for determining the steering angle.

Control techniques such as PID control or MPC control (model predictive control) can be applied to the steering control and speed control of the work vehicle 100. By applying these control techniques, it is possible to smooth the control that brings the work vehicle 100 closer to the target path P.

If an obstacle is detected by one or more obstacle sensors 130 while traveling, the control device 180 stops the work vehicle 100 or switches from automatic steering mode to manual steering mode. The control device 180 may control the drive device 140 to avoid the obstacle when an obstacle is detected.

Next, we will explain an example of the operation of outputting a warning when the work vehicle 100 deviates from the target route in automatic steering mode.

In this embodiment, when the work vehicle 100 is traveling in the automatic steering mode, the control device 180 causes the display device of the operation terminal 200 and the buzzer 220 to output a warning when the position of the work vehicle 100 is away from the target route by a reference distance or more. The display device of the operation terminal 200 and the buzzer 220 function as warning devices. The display device displays a warning display (e.g., a pop-up notification) indicating that the work vehicle 100 is deviating from the target route. The buzzer 220 outputs a warning sound. By such an operation, the user can be notified that the work vehicle 100 is deviating from the route. The reference distance may be set to a different value when the work vehicle 100 is traveling along the main route P1 and when the work vehicle 100 is traveling along the turning route P2. In the following description, the reference distance corresponding to the main route P1 may be referred to as the "first reference distance", and the reference distance corresponding to the turning route P2 may be referred to as the "second reference distance". The user may be able to set the first reference distance and the second reference distance individually by operating the operation terminal 200.

Fig. 11A is a diagram showing an example of a setting screen for route deviation notification. In the example of Fig. 11A, a reference distance (indicated as "route deviation amount" in Fig. 11A) can be set separately for the working area 70 and the headland 80. The user can set each reference distance from a setting screen such as that shown in Fig. 11A, which is displayed on the operation terminal 200. In the example of Fig. 11A, the first reference distance is set to 0.5 m, and the second reference distance is set to 1.1 m. The value of each reference distance can be changed by the user as desired within a specified range.

Figure 11B is a diagram showing another example of a setting screen related to route deviation notification. In the example shown in Figure 11B, the user can set one reference distance value. In other words, a common reference distance is set for the working area 70 and the headland 80. In this way, the setting screen may be configured so that a common reference distance is set for the working area 70 and the headland 80.

In this embodiment, a warning is output when the work vehicle 100 deviates from the route both when it is traveling in the work area 70 and when it is turning on the headland 80. Instead of this operation, for example, a warning may be output when the work vehicle 100 deviates from the route only when it is turning on the headland 80. In the headland 80, the ground may be roughened due to repeated turning, and route deviations tend to occur more easily than in the work area 70. In addition, since the headland 80 is located near the outer edge of the field, the impact of the work vehicle 100 deviating from the target route is generally greater than in the work area 70. For this reason, even if a warning is output when the work vehicle 100 deviates from the route only when the work vehicle 100 is turning on the headland 80, beneficial effects can be obtained.

The notification of route deviation may be given not only once, but multiple times. For example, if a certain time has elapsed since the control device 180 caused the warning device (the display device or the buzzer 220 in this embodiment) to output a warning and the position of the work vehicle 100 is still a reference distance or more away from the target route (the main route or the turning route), the control device 180 may cause the warning device to output a second warning that has a stronger warning effect than the first warning. For example, the control device 180 may cause the buzzer 220 to output a warning sound that is louder than the previously output warning sound. Alternatively, the control device 180 may cause the display device to output a warning display that is more noticeable than the previously output warning display.

Figure 12A is a flowchart showing an example of the operation of outputting two warnings when the vehicle deviates from the route. In this example, the control device 180 first acquires the deviation between the position of the work vehicle 100 and the target route (step S131). This step S131 represents the operation of acquiring the value of the deviation calculated in step S122 shown in Figure 9. The control device 180 judges whether the deviation is equal to or greater than the reference distance (step S132). If the deviation is less than the reference distance, the process returns to step S131. If the deviation is equal to or greater than the reference distance, the control device 180 causes the warning device to output a first warning (step S133). The first warning may be, for example, a warning sound by the buzzer 220 and/or a pop-up notification displayed on the display device. After step S133, the control device 180 judges whether a preset certain time (e.g., 2 seconds) has elapsed (step S134). When the certain time has elapsed, the control device 180 again acquires the deviation between the position of the work vehicle and the target route (step S135). The control device 180 determines whether the deviation is equal to or greater than the reference distance (step S136). If the deviation is less than the reference distance, the process returns to step S131. If the deviation is equal to or greater than the reference distance, the control device 180 causes the warning device to output a second warning (step S137). The second warning has a higher warning effect than the first warning. For example, a louder warning sound or a more noticeable warning display may be output as the second warning. The more noticeable warning display may be, for example, a pop-up notification in a larger window, a pop-up notification in a brighter color, or a flashing pop-up notification.

Figure 12B is a flowchart showing another example of the operation of outputting two warnings when the vehicle deviates from the route. In this example, after the control device 180 causes the warning device to output the first warning, when the position of the work vehicle 100 is separated from the target route (main route or turning route) by a second reference distance or more that is greater than the above-mentioned reference distance (referred to as the first reference distance), the control device 180 causes the warning device to output a second warning having a higher warning effect than the first warning. The second reference distance may be a value obtained by multiplying the first reference distance by a predetermined constant (e.g., 1.5 times) that is greater than 1. In the example of Figure 12B, the control device 180 acquires the deviation between the position of the work vehicle 100 and the target route (step S141). The control device 180 determines whether the deviation is equal to or greater than the first reference distance (step S142). If the deviation is less than the first reference distance, the process returns to step S141. If the deviation is equal to or greater than the reference distance, the control device 180 causes the warning device to output the first warning (step S143). The operations of steps S141 to S143 are the same as the operations of steps S131 to S133 shown in FIG. 12A. After step S143, the control device 180 again acquires the deviation between the position of the work vehicle 100 and the target route (step S144). The control device 180 determines whether the deviation is equal to or greater than the value (second reference distance) obtained by multiplying the first reference distance by a predetermined constant (e.g., 1.5) (step S145). If the deviation is less than the second reference distance, the process returns to step S141. If the deviation is equal to or greater than the second reference distance, the control device 180 outputs a second warning that is more effective than the first warning (step S146). Through the above operations, after the first warning is output, if the work vehicle 100 deviates further from the target route, the second warning that is more effective can be output.

In each of the above examples, when the position of the work vehicle 100 is separated from the turning path by a reference distance or more, a notification is given by the buzzer 220 or the like, but the work vehicle 100 continues to travel. Not limited to such an operation, the control device 180 may stop the work vehicle 100 after notifying the work vehicle 100 by the buzzer 220 or the like when the position of the work vehicle 100 is separated from the turning path by a reference distance or more. Alternatively, in the example shown in FIG. 12A or FIG. 12B, the work vehicle 100 may continue traveling when the first warning is output, and the work vehicle 100 may be stopped when the second warning is output. The reference distance for outputting a warning and the reference distance for stopping may be set separately. By stopping the work vehicle 100 when it deviates from the target path, further deviation from the target path can be avoided. Note that a warning when the path deviates may be output three or more times.

Next, we will explain an example of a pop-up notification that is displayed on the display device of the operation terminal 200.

13A is a diagram showing an example of a pop-up notification displayed when the vehicle deviates from the route. When the vehicle 100 is traveling in automatic steering, the display device of the operation terminal 200 displays a map of the field including the vehicle 100 and the target route P, as shown in FIG. 13A. When the vehicle 100 is away from the target route P by a reference distance or more, a beep is emitted from the buzzer 220 as a warning sound, and a pop-up notification 90 is displayed as shown in FIG. 13A. The pop-up notification 90 may include a message such as "You have deviated from the route by 1 m." In the example of FIG. 13A, in addition to the pop-up notification 90, a pop-up notification 91 is also displayed, which includes a display for confirming with the user whether or not to switch from the automatic steering mode to the manual steering mode. The user can switch from the automatic steering mode to the manual steering mode by pressing a button 98 displayed at the bottom right of the screen. The user can continue the automatic steering mode by pressing a button 99 displayed to the right of the button 98.

Figure 13B is a diagram showing an example of a display screen in a state in which the work vehicle 100 has been correctly positioned on the target route P by the user's driving after switching to the manual steering mode. In this example, the control device 180 causes the display device to display a pop-up notification 92 for the user to confirm whether or not to return to the automatic steering mode after turning in the manual steering mode is completed. When the user presses button 98, the control device 180 returns to the automatic steering mode in response to the operation. When the user presses button 99, the manual steering mode continues.

When the work vehicle 100 enters a turning path using automatic steering, the cruise control function may be active, i.e., the control device 180 may automatically control the speed, or the user may manually control the speed. When the work vehicle 100 enters a turning path with the cruise control function active and deviation from the path occurs, and the user switches from automatic steering mode to manual steering mode in accordance with the pop-up notification 91, the control device 180 may return to the automatic steering mode with the cruise control function active after the turning in the manual steering mode is completed. With such an operation, cruise control continues without the user having to perform an operation to enable the cruise control function again, thereby improving convenience.

In this embodiment, if the work vehicle 100 deviates from the target route P, a pop-up notification 90 is displayed on the operation terminal 200, but this function may be omitted. In that case, if a route deviation occurs, only a warning sound from the buzzer 220 is output as a warning. Even in that case, the user can immediately notice the route deviation by the warning sound from the buzzer 220. In a form in which a warning sound is output from the buzzer 220 or an audio output device such as a speaker as a warning, the user can notice the route deviation even if he or she is not looking at the screen of the display device. Since the user is not always looking at the screen, the user can be notified of the route deviation more quickly by having the audio output device output a warning sound.

In each of the above examples, the control device 180 causes a warning device such as the buzzer 220 to output a warning when the deviation between the position of the work vehicle 100 and the target route becomes equal to or greater than a reference distance. In addition to such an operation, the control device 180 may decelerate the work vehicle 100 or notify the user when the work vehicle 100 is likely to deviate significantly from the target route. For example, before causing the warning device to output a warning, the control device 180 may execute an operation to cause the warning device to output another warning and/or an operation to decelerate the work vehicle 100 when at least one of the time rate of change of the deviation between the position of the work vehicle 100 during turning and the turning route, the magnitude of the acceleration of the work vehicle 100, the time rate of change of the pitch angle of the work vehicle 100, and the time rate of change of the roll angle of the work vehicle 100 exceeds the respective threshold values. Such an operation makes it easier to prevent deviation from the target route when the work vehicle 100 is likely to deviate from the target route.

When the control device 180 causes the warning device to output a warning, the control device 180 may store the turning path in the storage device 170. When the work vehicle 100 next travels along a turning path adjacent to the turning path, the control device 180 may perform an operation to cause the warning device to output another warning and/or an operation to decelerate the work vehicle 100 before reaching the turning path. If the work vehicle 100 deviates significantly from the target turning path, there is a high possibility that the ground is rough around the turning path. By recording a turning path located on such a headland that is likely to be rough, the next time the work vehicle travels along an adjacent turning path located in the vicinity, it is possible to more smoothly turn on a rough headland by providing advance notice or decelerating before turning.

As described above, according to this embodiment, if the work vehicle 100 deviates from the route while turning using automatic steering, the user can be notified quickly. This allows the user to immediately perform an operation to return the work vehicle 100 to the target route by manual driving, for example. As a result, it is possible to solve problems such as the work vehicle 100 going outside the field or taking a long time to return to the target route. In addition, the user can notice at an early stage if the automatic steering accuracy required by the user is not being met.

(Embodiment 2)
Next, a second exemplary embodiment of the present disclosure will be described.

When the work vehicle 100 of this embodiment turns along a turning path by automatic steering, the speed is controlled according to the curvature of the turning path. This makes it possible to prevent the work vehicle 100 from deviating from the turning path even if the curvature of the turning path is large. The configuration of the work vehicle 100 of this embodiment is the same as the configuration of the work vehicle 100 in embodiment 1. Below, differences from embodiment 1 will be mainly described, and explanations of overlapping points will be omitted.

Figure 14A is a diagram showing an example of deviation from the target path P that can occur when the work vehicle 100 turns at high speed. A turning path generally has a large curvature (i.e., a small radius of curvature). For this reason, when the work vehicle 100 turns at high speed on the headland 80, depending on the turning performance of the work vehicle, the work vehicle 100 may deviate from the target turning path due to control delays, etc. In the diagram on the right of Figure 14A, the solid curved line shows an example of the actual travel path of the work vehicle 100. When such a deviation occurs, the work vehicle 100 may go outside the field when turning, or it may take time to return to the original path.

The above problem is not limited to turning routes, but can also occur when the main route includes a sharp curve. Figure 14B is a diagram showing an example of deviation from the target route P that can occur when the work vehicle 100 travels at high speed within the work area 70 along a main route that includes a sharp curve. As shown in the diagram on the right of Figure 14B, there is a possibility that the work vehicle 100 will deviate significantly from the target route P. When deviation from the target route P occurs in this way, overlapping or missing work locations may occur, making it necessary to redo the work.

Therefore, in this embodiment, in the automatic steering mode, the control device 180 controls the speed of the work vehicle 100 according to the curvature of the target route P. For example, the control device 180 reduces the speed of the work vehicle 100 as the curvature of the target route P increases (i.e., as the radius of curvature decreases). This type of control makes it possible to prevent the work vehicle 100 from deviating from the target turning route, for example, when turning on a headland. Furthermore, even if the target route P includes a sharp curve in the working area 70, it is possible to reduce overlap or gaps in working locations.

A specific example of speed control in this embodiment will be described below. An example of controlling the speed of the work vehicle 100 based on the radius of curvature of the target route will be described below. Instead of the radius of curvature, the reciprocal of the curvature, that is, the curvature, may be calculated, and the speed of the work vehicle 100 may be controlled based on the curvature.

First, we will explain how to calculate the radius of curvature.

Figure 15 is a diagram showing an example of the calculation position of the radius of curvature. The radius of curvature can be calculated, for example, for the position of a reference point of the work vehicle 100 that serves as the basis for steering control, or a position a predetermined distance (e.g., several meters) ahead of that position. The position of the reference point can be, for example, the position where the GNSS antenna is installed in the positioning device 120, the center position of the rear axle, or the center position of the work machine 300. When a position a predetermined distance ahead of the reference point position is used as the calculation position of the radius of curvature, the predetermined distance may be a fixed value, or the predetermined distance may be changed depending on the speed of the work vehicle 100.

Fig. 16 is a diagram showing an example of a method for calculating the radius of curvature. The radius of curvature is calculated by determining three points on the target route including any of the calculation positions shown in Fig. 15 and two points in the vicinity thereof, and determining a circle passing through these three points. For example, if the coordinates of the three points are ( _x1 , _y1 ), ( _x2 , _y2 ), and ( _x3 , _y3 ), the center coordinates of the circle are (a, b), and the radius is r, the center coordinates (a, b) and radius r of the circle can be obtained by solving the following simultaneous equations.
( _x1 -a) ² + ( _y1 -b) ² = ^r2
( _x2 - a) ² + ( _y2 - b) ² = ^r2
( _x3 -a) ² + ( _y3 -b) ² = ^r2
The control device 180 calculates the radius r as the radius of curvature.

Next, we will explain a specific example of the operation of limiting the speed of the work vehicle 100 depending on the radius of curvature.

Figure 17 is a flowchart showing a first example of the operation of limiting the speed of the work vehicle 100 according to the radius of curvature. As a premise, it is assumed that the work vehicle 100 runs with automatic steering, and the speed is adjusted by the user or maintained at a constant speed by auto-cruise control. The control device 180 executes the operation shown in Figure 17 when the work vehicle 100 turns along a turning path or runs along a main path including a curve. In the example of Figure 17, the control device 180 first determines whether the speed of the work vehicle 100 (hereinafter also referred to as "vehicle speed") is higher than a predetermined speed limit (e.g., 10 km/h) (step S201). The speed limit is determined in advance based on the turning performance of the work vehicle 100 and the minimum radius of curvature of the turning path, and is recorded in the storage device 170. If the vehicle speed does not exceed the speed limit, the operation of step S201 is executed again after a predetermined time has elapsed (e.g., 0.2 seconds). If the vehicle speed exceeds the speed limit, the control device 180 calculates the radius of curvature of the target route (turning route or main route) (step S202). The control device 180 calculates the radius of curvature at the position of the reference point of the work vehicle 100 at that time on the target route, or at a position a predetermined distance (for example, 1 meter) ahead of the reference point, by the above-mentioned method. Next, the control device 180 judges whether the calculated radius of curvature is less than a reference value (step S203). Note that judging whether the radius of curvature is less than the reference value is equivalent to judging whether the curvature exceeds the reference value. The radius of curvature or the reference value of the curvature is determined in advance according to the turning performance of the work vehicle 100 and recorded in the storage device 170. If the radius of curvature is equal to or greater than the reference value (i.e., if the curvature is equal to or less than the reference value), the process returns to step S201. If the radius of curvature is less than the reference value (i.e., if the curvature exceeds the reference value), the control device 180 limits the speed of the work vehicle 100 to less than the speed limit (step S204). The control device 180 automatically performs a brake operation or switches the gears to decelerate the work vehicle 100. The control device 180 may forcibly decelerate the work vehicle 100 even if the user is operating the accelerator. Alternatively, the control device 180 may prioritize the operation by the user when the user is operating the accelerator. In other words, the control device 180 may limit the speed according to the curvature only when the speed control is automatically performed by the auto cruise control. After step S204, the process returns to step S201. The above operations are repeated while the work vehicle 100 is traveling with automatic steering. If the automatic steering mode is released or a command to stop the operation is issued while the operation shown in FIG. 17 is being performed, the operation is terminated. Such operations can prevent the work vehicle 100 from deviating from the target route when turning or traveling on a curve.

Figure 18 is a flowchart showing a second example of the operation of limiting the speed of the work vehicle 100 according to the radius of curvature. In this example, the speed limit is not a fixed value, but a variable value determined according to the radius of curvature. Data such as a table or a function that specifies the correspondence between the radius of curvature and the speed limit is pre-recorded in the storage device 170. Note that since the radius of curvature is the reciprocal of the curvature, the data that specifies the correspondence between the radius of curvature and the speed limit is equivalent to the data that specifies the correspondence between the curvature and the speed limit. In the example of Figure 18, when the work vehicle 100 is traveling along the target route by automatic steering, the control device 180 calculates the radius of curvature of the target route (step S211). Next, the control device 180 determines the speed limit based on the data recorded in the storage device 170 and the calculated radius of curvature (step S212). The control device 180 determines whether the vehicle speed exceeds the speed limit (step S213). If the vehicle speed does not exceed the speed limit, the process returns to step S211. If the vehicle speed exceeds the speed limit, the control device 180 limits the vehicle speed to less than the speed limit (step S214). After step S214, the process returns to step S211. The above operations are repeated while the work vehicle 100 is traveling with automatic steering. If the automatic steering mode is released or a command to stop the operation is issued while the operation shown in FIG. 18 is being performed, the operation ends. This operation makes it possible to prevent the work vehicle 100 from deviating from the target route when turning or traveling around a curve.

Next, with reference to Figures 19A to 19D, we will explain an example of data that defines the correspondence between curvature and speed limits.

Figure 19A is a graph showing an example of a function in which the speed limit increases monotonically and linearly with increasing radius of curvature. Figure 19B is a graph showing an example of another function in which the speed limit increases monotonically with increasing radius of curvature. In the example of Figure 19B, data of a broken line function in which multiple points are linearly interpolated is used. Figure 19C is a graph showing an example of a function in which the speed limit increases nonlinearly with increasing radius of curvature. Figure 19D is a graph showing an example of a function in which the speed limit is proportional to the square root of the radius of curvature. In the example of Figure 19D, the vehicle speed is limited so that the lateral acceleration of the work vehicle 100 is equal to or less than a threshold value. Steering control is performed appropriately when the lateral acceleration is small. If the lateral acceleration is a, the vehicle speed is v, and the radius of curvature is r, the relationship v = √(r a) is established. It is effective to set the speed limit according to a function such as that shown in Figure 19D so that the lateral acceleration a is equal to or less than a certain value even when the radius of curvature is small (i.e., the curvature is large). The data of a function or table as shown in any one of Figures 19A to 19D may be used as data defining the correspondence between the curvature and the speed limit. As in these examples, the speed limit may be set to a lower value as the radius of curvature becomes smaller (i.e., as the curvature becomes larger).

The control device 180 may repeatedly calculate the curvature of the turning path while the work vehicle 100 is traveling, and change the speed limit according to the rate of change of the curvature over time. Calculating the curvature is synonymous with calculating the radius of curvature, and changing the speed limit according to the rate of change of the curvature is synonymous with changing the speed limit according to the rate of change of the radius of curvature. Cases in which the work vehicle 100 deviates from the target path include not only cases in which the work vehicle 100 cannot turn even if the steering angle is maximized because the radius of curvature is too small (i.e., the curvature is too large) relative to the speed of the work vehicle 100, but also cases in which the work vehicle 100 cannot turn even if the steering speed is maximized because the rate of change of the curvature over time is too high relative to the speed. For this reason, it is effective to change the speed limit according to the rate of change of the curvature (or the radius of curvature) over time. For example, the greater the magnitude (i.e., the absolute value) of the rate of change of the curvature (or the radius of curvature) over time, the more effective it is to increase the speed limit.

Figure 20 is a flowchart showing an example of the operation of limiting the speed of the work vehicle 100 according to the time rate of change of the radius of curvature. In this example, the control device 180 calculates the time rate of change of the radius of curvature of the target route (i.e., the differential value) when the work vehicle 100 is traveling with automatic steering (step S221). Next, the control device 180 determines the speed limit based on the table previously recorded in the storage device 170 and the calculated time rate of change of the radius of curvature. The control device 180 determines whether the vehicle speed exceeds the speed limit (step S223). If the vehicle speed does not exceed the speed limit, the process returns to step S221. If the vehicle speed exceeds the speed limit, the control device 180 limits the vehicle speed to less than the speed limit (step S224). After step S224, the process returns to step S221. The above operations are repeated while the work vehicle 100 is traveling with automatic steering. If the automatic steering mode is released or a command to stop the operation is issued while the operation shown in Figure 20 is being performed, the operation is terminated. This operation can prevent the work vehicle 100 from deviating from the target route when turning or traveling along a curve.

21A to 21C are graphs showing examples of functions defined by the table used in the example of FIG. 20. In these graphs, the horizontal axis shows the absolute value of the time rate of change of the radius of curvature. FIG. 21A shows an example of a function in which the speed limit increases monotonically and linearly with an increase in the absolute value of the time rate of change of the radius of curvature. FIG. 21B shows another example of a relationship in which the speed limit increases monotonically with an increase in the absolute value of the time rate of change of the radius of curvature. In the example of FIG. 21B, data of a function linearly interpolated between multiple points is used. FIG. 21C shows an example of a function in which the speed limit increases monotonically and nonlinearly with an increase in the absolute value of the time rate of change of the radius of curvature. Data of a function or table such as those shown in any of FIG. 21A to 21C can be used as data that defines the correspondence relationship between the rate of change of the curvature and the speed limit. In these examples, the speed limit is set to a lower value as the absolute value of the time rate of change of the curvature increases.

Next, we will explain another example of the operation of limiting the speed when the work vehicle 100 turns along a turning path.

Figure 22 shows an example of a situation in which the work vehicle 100 is traveling along one main path P1 in the work area 70 toward the headland 80. When the work vehicle 100 is traveling toward the headland 80 at a relatively high speed, the control device 180 suppresses the work vehicle 100 from deviating from the turning path P2 by limiting the speed according to the curvature of the turning path P2. In one example, when the work vehicle 100 reaches the start point S0 of the turning path P2, if the speed of the work vehicle 100 exceeds the speed limit and the curvature of the turning path P2 exceeds a reference value, the control device 180 reduces the speed of the work vehicle 100 to below the speed limit. If the curvature of the turning path P2 is too large or the speed of the work vehicle 100 entering the headland 80 is too high, it may not be enough to start decelerating at the timing when the work vehicle 100 reaches the start point S0 of the turning path P2. In such a case, the control device 180 may start decelerating the work vehicle 100 when the work vehicle 100 reaches a point that is a predetermined distance d1 before the start point of the turning path P2. The predetermined distance d1 may be determined according to the curvature of the turning path P2 or the speed of the work vehicle 100.

The control device 180 may perform the speed control according to the curvature of the route described above only when the cruise control function is enabled. Alternatively, the control device 180 may perform the speed control according to the curvature of the route described above even when the cruise control function is disabled, that is, when the user is operating the accelerator pedal himself.

When the cruise control function is enabled, the control device 180 drives the work vehicle 100 along the main path P1 at a reference speed set by the user. When the work vehicle 100 approaches the turning path P2 in this state, as described above, the control device 180 decelerates the work vehicle 100 along the turning path P2 to a speed determined according to the curvature of the turning path P2 and turns the work vehicle 100. After turning, the control device 180 may return the speed of the work vehicle 100 to the reference speed and continue cruise control. In other words, after turning, the control device 180 may drive the work vehicle 100 at the reference speed along the other main path P1 connected to the turning path P2.

In this embodiment, the steering of the work vehicle 100 is controlled by the ECU 182 in accordance with commands from the ECU 183 shown in FIG. 3. The speed of the work vehicle 100 is controlled by the ECU 181. The ECU 182 functions as a first control circuit that controls the steering of the work vehicle 100. The ECU 181 functions as a second control circuit that controls the speed of the work vehicle.

When the work vehicle 100 enters a predetermined range including the turning path P2, the control device 180 may display a pop-up notification on the display device of the operation terminal 200 indicating that the work vehicle 100 has approached the turning path P2. The predetermined range including the turning path P2 is, for example, a range located at a predetermined distance from the end of the turning path P2.

Figure 23 is a diagram showing an example of a pop-up notification indicating that the work vehicle 100 is approaching the turning path P2. In the example of Figure 23, when the work vehicle 100 approaches the headland, a pop-up notification 93 including information on the time and distance required to reach the headland is displayed on the display device. The pop-up notification 93 shown in Figure 23 includes the words "5 seconds to headland" and "14.0 m", as well as a mark indicating that the turning direction is left.

The control device 180 may change how close the work vehicle 100 must be to the turning path P2 (or headland) before displaying the pop-up notification 93, depending on the speed of the work vehicle 100. Also, the user may be able to set how close the work vehicle 100 must be to the turning path P2 before displaying the pop-up notification 93.

In the example of FIG. 23, a pop-up notification 94 is also displayed at the bottom left of the screen, urging the user to check the settings for automatic headland turning, auto cruise control at the headland, and HMS trigger (hereinafter, these functions may be referred to as "semi-automatic driving functions"). The HMS trigger function is a function that executes a series of operations according to a pre-recorded operation sequence when turning at the headland. The pop-up notification 94 in the example of FIG. 23 indicates that automatic headland turning is ON, HMS trigger is OFF, auto cruise control at the headland is ON, and the set speed for auto cruise control is 3 km/h. The user can change the settings for these semi-automatic driving functions by pressing a specific icon or button on the display screen or a specific switch provided in the driver's seat.

In this way, the pop-up notification that is displayed when the work vehicle 100 approaches the turning path P2 may include at least one piece of information: the turning direction, the distance and/or time to the start point of the turn, whether or not to turn using automatic steering, and the speed during the turn. The pop-up notification may also include other information, such as the line numbers before and after the turn.

23 includes an icon 85 for transitioning to a setting screen, an icon 86 for switching the automatic steering (autosteer) function ON/OFF, an indicator 96 indicating that the auto-cruise control function is enabled (ON), and an indicator 97 indicating that the automatic headland turning function is enabled (ON). The control device 180 turns on the indicator 96 when the auto-cruise control function is enabled, and turns on the indicator 97 when the automatic headland turning function is enabled. When the control device 180 is limiting the speed of the work vehicle 100 based on the curvature of the turning path, the control device 180 may display information indicating that the speed is being limited on the display device of the operation terminal 200. For example, when the control device 180 is limiting the speed of the work vehicle 100 based on the curvature of the turning path, the control device 180 may display that the speed is being limited by flashing the indicator 97. Such a display can inform the user that the deceleration is not due to a malfunction but is to avoid deviation from the path.

When the work vehicle 100 enters a predetermined range including the turning path, the control device 180 may cause an audio output device such as the buzzer 220 or the speaker of the operation terminal 200 to emit a warning sound. By not only displaying a pop-up notification but also emitting a warning sound, the user can be effectively notified of the approach to the headland.

(Embodiment 3)
Next, a third exemplary embodiment of the present disclosure will be described.

As mentioned above, the semi-automatic driving function includes a headland turning function, an auto-cruise control function, and an HMS trigger function. A work vehicle 100 capable of semi-automatic driving performs control that combines these functions. Normally, turning is performed on the headland, but depending on the work situation, the user may perform turning at any time. The function that allows the user to instruct turning using automatic steering at any time is referred to in this specification as "on-demand turning."

When a user turns the work vehicle 100 at any time, it is up to the user whether or not to always use the HMS trigger function and the auto cruise control function in combination. Depending on the situation, the user may turn while performing work such as plowing with the work implement 300, or may turn with the work implement 300 stopped and raised.

In this embodiment, when an on-demand turning operation is performed by the user, the control device 180 displays a pop-up on the display device to allow the user to select whether or not to use the HMS trigger function, etc. That is, when the user performs an operation to instruct turning while the work vehicle 100 is traveling along one of the multiple main routes by automatic steering, the control device 180 displays a pop-up on the display device in response to the operation. The pop-up includes a display for allowing the user to select whether or not to cause the work vehicle 100 to perform a series of operations according to a pre-recorded operation sequence. When it is selected that the work vehicle 100 is to perform a series of operations, the control device 180 causes the work vehicle 100 to perform a turn accompanied by a series of operations according to a pre-recorded operation sequence. Conversely, when it is selected that the work vehicle 100 is not to perform a series of operations, the control device 180 causes the work vehicle 100 to perform a turn without the series of operations. Such an operation allows the user to select whether or not to use the HMS trigger function depending on the situation when turning within the work area.

As described above, the series of operations may include a first operation performed at the start of turning and a second operation performed at the end of turning. The first operation may include at least one of the following operations: raising the working machine 300 connected to the work vehicle 100, stopping the power output to the working machine 300, stopping the differential lock function of the work vehicle 100, switching from two-wheel drive mode to four-wheel drive mode, and reducing the engine speed of the work vehicle 100. The second operation may include at least one of the following operations: lowering the working machine 300, starting the power output to the working machine 300, starting the differential lock function, switching from four-wheel drive mode to two-wheel drive mode, and increasing the engine speed. The control device 180 can display a setting screen on the display device to allow the user to set the contents of the series of operations. The control device 180 stores an operation sequence based on the contents of the set series of operations in the storage device 170.

The operation of the work vehicle 100 of this embodiment will be described in more detail below. The configuration of the work vehicle 100 of this embodiment is the same as that of embodiment 1. Below, differences from embodiment 1 will be mainly described.

24 is a diagram showing an example of the operation of the work vehicle 100 in this embodiment. As shown by the arrow in FIG. 24, the work vehicle 100 in this embodiment has an on-demand turning function that automatically turns in response to a user's operation while traveling along the main route P1 with automatic steering. The user can instruct on-demand turning by, for example, pressing a specific button or icon on a screen displayed on the operation terminal 200 when the work vehicle 100 is traveling with automatic steering. When on-demand turning is instructed, the control device 180 displays a pop-up on the display device for the user to select whether or not to perform a series of operations similar to the normal turning operation in the headland 80. After the user selects whether or not to perform the series of operations, the control device 180 causes the work vehicle 100 to perform a turn. In this on-demand turning, a route deviation notification by a warning device such as the buzzer 220 in embodiment 1 and/or speed control according to the curvature in embodiment 2 may be performed, as when the work vehicle 100 turns along the turning route P2 shown by the dotted line in FIG. 24.

In this embodiment, the control device 180 continues the automatic steering mode even after the work vehicle 100 executes a turn in response to a user operation instructing the work vehicle to turn. This allows the work vehicle 100 to continue traveling by automatic steering after starting to turn without the user having to perform any particular operation.

Figure 25 is a diagram showing an example of a screen displayed on the display device when the work vehicle 100 is traveling along the linear main path P1 with automatic steering. This screen includes an icon 85 for configuring settings related to semi-automatic driving, and an icon 87 for instructing on-demand turning. When the user presses icon 85, the screen transitions to a settings screen for configuring settings related to the semi-automatic driving function, including on-demand turning. When the user presses icon 87 while the work vehicle 100 is traveling, an on-demand turning operation is initiated. At this time, a pop-up is first displayed, prompting the user to select whether or not to execute a series of operations according to a pre-recorded HMS operation sequence.

26 is a diagram showing an example of a pop-up screen that is displayed when the user presses the icon 87. According to this pop-up screen, the user can set the on-demand turning operation. In this example, the pop-up includes an arrow for specifying the turning direction (left/right), an input box for specifying the number of rows to skip when turning, an indication of whether or not auto-cruise control is being executed during turning (ON/OFF) and the speed when it is being executed, an indication of whether or not auto-cruise control is being executed after turning (ON/OFF) and the speed when it is being executed, and a button for selecting ON/OFF of the HMS trigger. When the user sets according to this pop-up screen and presses the check button 88 at the bottom right, the control device 180 turns the work vehicle 100 according to the set contents. When the user presses the cancel button 89, the on-demand turning is canceled and traveling along the main route P1 continues.

In the example of FIG. 26, when starting an on-demand turn, the user can specify the turning direction, the number of rows to skip, and whether or not to enable the HMS trigger function. Furthermore, it may be possible to change whether or not to enable the autocruise function during and after the turn, and the speed at which it is enabled. In this way, the pop-up includes a display for allowing the user to set various items such as the turning direction and the number of rows to skip. The control device 180 causes the work vehicle 100 to perform a turn according to the contents of the turning direction, the number of rows to skip, etc. that have been set.

In the example of FIG. 26, cruise control is set to ON both during and after turning. In such a case, the control device 180 continues to enable the cruise control function even after causing the work vehicle 100 to turn in response to a user operation instructing the work vehicle 100 to turn while the cruise control function is enabled. In this case, the work vehicle 100 can automatically turn and travel after turning without any operation by the user.

Settings for on-demand turning can be made in advance. Figure 27 shows an example of a screen to which the screen transitions after pressing icon 85 in Figure 25. In this example, settings for semi-automatic driving in each of the work area 70 (field) and headland 80 can be made. When the user selects either the "field" or "headland" button included in this screen and presses the check button at the bottom right, the screen transitions to a screen for making settings for semi-automatic driving in the selected area.

Figure 28 is a diagram showing an example of a screen for setting semi-automated driving on the headland. On this screen, the user can set the HMS trigger function, the auto cruise control function, and the route deviation amount when notifying deviation from the route. The user can enable/disable the HMS trigger function when turning by pressing the "auto HMS trigger" icon 81. The user can also enable/disable the auto cruise control function by pressing the "auto cruise control" icon 82. In the example of Figure 28, the user can also set the speed during auto cruise control and the route deviation amount when notifying deviation from the route. The contents set on this screen can be applied not only to headland turns but also to on-demand turns. Different settings may be possible for headland turns and on-demand turns.

When an instruction for on-demand turning is issued by the user, the control device 180 creates an on-demand turning route based on the spacing between the rows before and after the turn, and turns the work vehicle 100 along the route. At this time, if the spacing between the rows before and after the turn is short, the work vehicle 100 may run over an area where work such as plowing has already been completed. In such a case, the control device 180 may display a warning such as a pop-up on the display device to warn the user. When this function is implemented, the control device 180 sequentially stores in the storage device 170 the areas of the work area 70 where work by the work vehicle 100 has been completed. When the created route overlaps with the area where work has been completed, the control device 180 causes the display device to display a warning. When the control device 180 causes the display device to display a warning, the control device 180 may further cause the display device to display a user interface that allows the user to change the turning route. For example, the user may be able to select a turning route in a pop-up display such that the work vehicle 100 does not run over an area where work has already been completed.

29A is a diagram showing an example of a route created by the control device 180 when an instruction for on-demand turning is issued by the user. In this example, the work vehicle 100 uses the working machine 300 to perform plowing work. In the following description, the area of the work area 70 where plowing work has been completed by the working machine 300 is referred to as "already cultivated land", and the area where plowing work has not yet been performed is referred to as "uncultivated land". In the example shown in FIG. 29A, a part of the work area 70 is already cultivated land 71, and the rest of the work area 70 is uncultivated land 72. A part of the route created by the control device 180 overlaps with the already cultivated land 71. When the work vehicle 100 travels along such a route, the work vehicle 100 will step on a part of the already cultivated land 71. There is no problem in turning along such a route on the pillow area, but in on-demand turning, turning along such a route may require redoing the work. In such a case, the control device 180 displays a pop-up on the display device to allow the user to select a turning route that does not step on the cultivated land 71. For example, a pop-up may be displayed that has a user interface that allows the user to select a route such as that shown by the dashed arrow in FIG. 29B.

30A is a diagram showing an example of a pop-up that is displayed when a route that overlaps with cultivated land is created during on-demand turning. In this example, a pop-up 95 containing the message "There is a possibility that you will step on cultivated land" is displayed. In the example of FIG. 30A, a message "Do you want to change the route?" is also displayed in a window at the bottom of the screen. If the route is to be changed, the user presses the check button 98. If the route is not to be changed, the user presses the cancel button 99. When the user presses the check button 98, the control device 180 displays candidates for the changed route on the display device, as shown in FIG. 30B, for example. In the example of FIG. 30B, one candidate route is displayed, but multiple candidates may be displayed. Alternatively, the user may be able to edit the route by an operation such as drag and drop. In the example of FIG. 30B, one of the candidate routes is selected, and a message "Do you want to change to this route?" is displayed in a window at the bottom of the screen. When the user presses the check button 98, the changed route is decided, and the work vehicle 100 starts turning along the route. When the user presses the cancel button 99, the change is canceled.

In this way, the control device 180 can display candidate turning paths on the display device, allowing the user to check the movement of the work vehicle 100 after the turn begins. If the movement is not what the user intended, the user can reset the route. This function makes it possible to prevent the work vehicle 100 from stepping on areas that have already been worked on, such as cultivated land, when turning on demand.

As described above, in this embodiment, when the user performs an operation to start on-demand turning, a pop-up that allows the user to confirm and change the settings of semi-automatic driving functions such as the HMS trigger function is displayed on the display device. This prevents the semi-automatic driving function from being activated unintentionally by the user during on-demand turning, and allows the user to freely set operations specific to on-demand turning. Furthermore, since the user can select the route to be taken when turning, it is possible to prevent the work vehicle 100 from stepping on an area that has already been worked on during on-demand turning. This eliminates the need to redo work, and improves work efficiency.

(Embodiment 4)
Next, a fourth embodiment of the present disclosure will be described.

When turning around the headland using automatic steering, the turning path is created based on geometric conditions such as the working width or the turning radius. However, if the work vehicle 100 enters the headland at a speed greater than a predetermined speed and attempts to turn along the turning path, there is a possibility that it will deviate significantly from the path. If shift control or braking control is possible through electronic control, it is relatively easy to instantly slow down or brake when entering. However, if shift control or braking control is not electronic, such as when it is performed hydraulically, it is not easy to instantly slow down or brake.

Therefore, in this embodiment, when the work vehicle 100 enters the headland using automatic steering, if the speed exceeds a threshold, the automatic steering is released. Also, even if the speed does not exceed the threshold when entering the headland, if the speed exceeds the threshold during turning, the automatic steering is released. After the automatic steering is released, the user drives the work vehicle 100 using manual steering. By the user manually steering, deviation from the target route can be suppressed.

The configuration of the work vehicle 100 in this embodiment is the same as the configuration of the work vehicle 100 in embodiment 1. Below, differences from embodiment 1 will be mainly described.

Figure 31 is a diagram for explaining the operation of the work vehicle 100 of this embodiment. Figure 31 shows the work vehicle 100 traveling along one of the main routes P1 in the work area 70 toward the pillow area 80. In the automatic steering mode, the control device 180 in this embodiment determines whether the speed of the work vehicle 100 exceeds a threshold value when the work vehicle 100 travels along one of the main routes P1 and reaches the start point S0 of the turning path P2 or a point S2 a predetermined distance d2 before the start point S0. In the example of Figure 22, the position of the GNSS sensor mounted on the cabin of the work vehicle 100 is set as the reference position of the work vehicle 100, and when the reference position reaches a point S2 a predetermined distance d2 before the start point S0 of the turning path P2, it is determined whether the speed of the work vehicle 100 exceeds a threshold value. If the speed of the work vehicle 100 exceeds the threshold value, the control device 180 cancels the automatic steering mode and switches to the manual steering mode. If the speed of the work vehicle 100 does not exceed the threshold, the control device 180 continues the automatic steering mode and controls the steering of the work vehicle 100 so that the work vehicle 100 turns along the turning path.

The distance d2 between the point S2 at which it is determined whether the speed of the work vehicle 100 exceeds the threshold and the start point S0 of the turning path P2 is not limited to a fixed value and can be set to any value. The distance d2 may be set to a value that differs depending on the speed, such as the distance traveled by the work vehicle 100 in a predetermined time (e.g., 5 seconds). Alternatively, the distance d2 may be determined according to the curvature of the turning path P2. Depending on the situation, the distance d2 may be set to zero (0).

The distance d2 may be determined based on data such as a table or a function previously recorded in the storage device 170. For example, the storage device 170 may store data such as a table or a function that defines the correspondence between the curvature of the turning path P2 and the distance d2. Figures 32A to 32C show examples of functions that indicate the correspondence between the curvature of the turning path P2 and the distance d2. The control device 180 may determine the distance d2 according to the curvature of the turning path P2 based on data that defines a function such as that shown in any of Figures 32A to 32C. The distance d2 may be set so that it is longer as the curvature of the turning path is larger. If the curvature is not constant on the turning path P2, the predetermined distance may be determined according to the maximum curvature on the turning path P2. The storage device 170 may store data such as a table or a function that defines the correspondence between the speed of the work vehicle 100 and the distance d2. Figures 33A to 33C show examples of functions that indicate the correspondence between the speed of the work vehicle 100 and the distance d2. The control device 180 may determine the distance d2 according to the speed of the work vehicle 100 traveling along the main path P1, based on data that defines a function such as that shown in any one of Figures 33A to 33C. The distance d2 may be set to be longer as the speed of the work vehicle 100 increases.

The speed threshold for determining whether to cancel the automatic steering mode is not limited to a fixed value and may be changeable. For example, the speed threshold may be changed according to the curvature of the turning path P2. The storage device 170 may store data such as a table or a function that defines the correspondence between the curvature of the turning path P2 and the speed threshold. Figures 34A to 34C show examples of functions that show the correspondence between the curvature of the turning path P2 and the speed threshold. The control device 180 may determine the speed threshold according to the curvature of the turning path P2 based on data that defines a function such as that shown in any of Figures 34A to 34C. The speed threshold may be set to a smaller value as the curvature of the turning path P2 increases.

Figure 35 is a flowchart showing an example of the operation of the control device 180 in this embodiment. While the work vehicle 100 is traveling with automatic steering, the control device 180 executes the operation shown in Figure 35. The control device 180 calculates the distance D between the position of the work vehicle 100 and the start point S0 of the next turning path P2 (step S401). The control device 180 judges whether the calculated distance D is equal to or less than the above-mentioned predetermined distance d2 (step S402). If the distance D is greater than the distance d2, the process returns to step S401. If the distance D is equal to or less than the distance d2, the control device 180 judges whether the speed (vehicle speed) of the work vehicle 100 at that time exceeds the threshold value (step S403). If the vehicle speed does not exceed the threshold value, the control device 180 continues the automatic steering mode and judges whether the turning has ended (step S404). If the turning has not ended in step S404, the process returns to step S403. If the turning is completed in step S404, the process returns to step S401, and the same operation is performed for the next turning route. If the vehicle speed exceeds the threshold in step S403, the control device 180 releases the automatic steering mode and switches to the manual steering mode (step S405). After step S405, the control device 180 judges whether the turning is completed (step S406). If the turning is not completed in step S406, the judgment in step S406 is repeated at regular intervals (for example, several milliseconds to several hundred milliseconds) until the turning is completed. If the turning is completed in step S406, the control device 180 switches from the manual steering mode to the automatic steering mode (step S407). After that, the process returns to step S401, and the same operation is performed for the next turning route. If the user performs an operation to release the automatic steering mode or receives a command to stop the operation while the operation shown in FIG. 35 is being performed, the operation is terminated.

35, when the control device 180 determines in step S403 that the vehicle speed does not exceed the threshold, the control device 180 continues the automatic steering mode and controls the steering of the work vehicle 100 so that the work vehicle 100 turns along the turning path P2. Thereafter, the control device 180 performs the determination in step S403 again at predetermined time intervals unless the turning is completed. This is because the speed of the work vehicle 100 may increase during turning due to the accelerator operation by the user. When the control device 180 determines that the speed of the work vehicle 100 exceeds the threshold during turning, the control device 180 proceeds to step S405, cancels the automatic steering mode, and switches to the manual steering mode. In this way, even if the vehicle speed does not exceed the threshold before starting the turning, if the vehicle speed exceeds the threshold during turning, the automatic steering is canceled. Once the automatic steering is canceled, the user drives the work vehicle 100 with manual steering. By operating the control device by the user, the work vehicle 100 can be prevented from deviating from the turning path.

In the above example, when the control device 180 cancels the automatic steering mode and switches to the manual steering mode in step S405, it returns to the automatic steering mode in step S407 after turning in the manual steering mode is completed. This return may be performed automatically or based on a user operation. After turning in the manual steering mode is completed, the control device 180 may display a pop-up notification on the display device to confirm with the user whether or not to return to the automatic steering mode. In that case, the control device 180 returns to the automatic steering mode in response to the user's operation. This pop-up notification is, for example, the same notification as the pop-up notification 92 shown in FIG. 13B.

In the example of FIG. 35, the control device 180 determines whether the speed of the work vehicle 100 exceeds the threshold and switches the mode, regardless of whether the cruise control function is enabled or disabled. The control device 180 may determine whether the speed of the work vehicle 100 exceeds the threshold and switch the mode only when the cruise control function is enabled. In that case, since the vehicle speed does not increase during turning by automatic steering, if it is determined in step S403 that the vehicle speed does not exceed the threshold, the control device 180 does not transition to step S404, but instead performs a turn by automatic steering and then returns to step S401.

When the control device 180 cancels the automatic steering mode and switches to the manual steering mode in step S405 while the cruise control function is enabled, after the turning in the manual steering mode is completed, in step S407, the control device 180 may return to the automatic steering mode with the cruise control function enabled. This operation can eliminate the need for the user to enable the cruise control again after the turning is completed with manual steering.

In this embodiment, as in the second embodiment, the control device 180 may cause the display device to display a pop-up notification indicating that the work vehicle 100 is approaching the turning path P2 when the work vehicle 100 enters a predetermined range that includes the turning path P2. An example of such a pop-up notification is as shown in FIG. 23. Also, a speed limit may be imposed according to the curvature of the turning path P2 in the second embodiment.

When switching from the automatic steering mode to the manual steering mode, the control device 180 may cause the display device to display a pop-up notification indicating that the mode has been switched. FIG. 36 is a diagram showing an example of such a pop-up notification. In this example, a pop-up notification is displayed that includes the message "Switched to manual steering mode." The user can see this notification and manually control the steering of the work vehicle 100 to prevent the work vehicle 100 from deviating from the turning path.

The control device 180 may cause an audio output device such as a buzzer 220 to emit a warning sound when the work vehicle 100 enters a predetermined range including the turning path. Since the user is not always looking at the display screen, the warning sound can be used to more effectively alert the user when the work vehicle 100 is approaching the turning path. The control device 180 may cause an audio output device such as a buzzer 220 to emit a warning sound when the automatic steering mode is switched to the manual steering mode. This can effectively notify the user that the mode has been switched.

Other Embodiments
Each technique of the above-described first to fourth embodiments can be combined with a technique of another embodiment as long as no contradiction occurs.

In the above embodiments, the work vehicle 100 may be an unmanned work vehicle that performs automatic driving. In that case, components that are necessary only for manned driving, such as a cabin, a driver's seat, a steering wheel, and an operation terminal, may not be provided in the work vehicle 100. The unmanned work vehicle may perform operations similar to those in each of the above-mentioned embodiments by autonomous driving or remote operation by a user.

A control system that provides the various functions in the above embodiments can also be retrofitted to a work vehicle that does not have those functions. Such a control system can be manufactured and sold independently of the work vehicle. A computer program used in such a control system can also be manufactured and sold independently of the work vehicle. The computer program can be provided, for example, by being stored in a computer-readable non-transitory storage medium. The computer program can also be provided by downloading via a telecommunications line (for example, the Internet).

As described above, the present disclosure includes the control system and work vehicle described in the following items.

[Item a1]
A control system for a work vehicle that performs automatic steering operation,
A storage device that stores a target route for the work vehicle;
a control device that controls steering of the work vehicle so that the work vehicle travels along the target route based on the position of the work vehicle specified by the positioning device and the target route stored in the storage device;
Equipped with
the target route includes a plurality of parallel main routes and one or more turning routes connecting the plurality of main routes;
the control device causes a warning device to output a warning when a position of the work vehicle deviates from the turning path by a reference distance or more while the work vehicle is turning along one of the turning paths by automatic steering;
Control system.

[Item a2]
The control system according to item a1, wherein the warning device includes a buzzer or a speaker that outputs a warning sound as the warning.

[Item a3]
The control system described in item A1 or A2, wherein the control device causes the warning device to output a warning having a greater warning effect than the warning when a certain time has elapsed since the warning device output the warning and the position of the work vehicle is away from the turning path by more than the reference distance.

[Item a4]
The control system described in item A1 or A2, wherein after causing the warning device to output the warning, if the position of the work vehicle deviates from the turning path by more than a value obtained by multiplying the reference distance by a predetermined constant greater than 1, the control device causes the warning device to output a warning having a greater warning effect than the warning.

[Item a5]
The control device includes:
displaying a setting screen on a display device for allowing a user to set the reference distance;
determining whether or not the position of the work vehicle is away from the turning path by the reference distance or more based on the set reference distance;
A control system according to any one of items a1 to a4.

[Item a6]
The control device, when the work vehicle is traveling along one of the plurality of main routes by automatic steering, causes the warning device to output a warning when the position of the work vehicle is away from the main route by more than the reference distance or another reference distance different from the reference distance.

[Item a7]
The control system according to any one of items a1 to a6, wherein the warning device includes a display device that outputs a pop-up notification as the warning.

[Item a8]
The control device is capable of switching between an automatic steering mode and a manual steering mode,
the pop-up notification includes a display for confirming with a user whether or not to switch from the automatic steering mode to the manual steering mode.
The control system according to item a7.

[Item a9]
The control device includes:
switching from the automatic steering mode to the manual steering mode in response to an operation by the user;
After the turning in the manual steering mode is completed, the automatic steering mode is returned to.
The control system according to item a8.

[Item a10]
The control device includes:
After the turning in the manual steering mode is completed, a pop-up notification is displayed on the display device to prompt the user to decide whether or not to return to the automatic steering mode;
returning to the automatic steering mode in response to an operation by the user;
The control system according to item a9.

[Item a11]
The control device includes:
a cruise control function for causing the work vehicle to travel at a reference speed set by a user;
The work vehicle enters the turning path with the cruise control function enabled, the user switches from the automatic steering mode to the manual steering mode in accordance with the pop-up notification, and after the turning in the manual steering mode is completed, the work vehicle returns to the automatic steering mode with the cruise control function enabled.
The control system according to item a9 or a10.

[Item a12]
The control system according to any one of items a1 to a11, wherein the control device stops the work vehicle when the position of the work vehicle is away from the turning path by more than the reference distance.

[Item a13]
A control system described in any of items a1 to a12, wherein the control device causes the warning device to output another warning and/or decelerates the work vehicle when at least one of the time rate of change of the deviation between the position of the work vehicle during a turn and the turning path, the magnitude of the acceleration of the work vehicle, the time rate of change of the pitch angle of the work vehicle, and the time rate of change of the roll angle of the work vehicle exceeds their respective threshold values before causing the warning device to output the warning.

[Item a14]
The control device includes:
When the warning device is caused to output the warning, the turning path is stored in the storage device;
When the work vehicle next travels along a turning path adjacent to the turning path, causing the warning device to output another warning and/or decelerating the work vehicle before the work vehicle reaches the turning path.
A control system according to any one of items a1 to a13.

[Item a15]
The plurality of main paths are located within a farm field,
The one or more turning paths are located on a headland of the field,
A control system according to any one of items a1 to a14.

[Item a16]
A control system according to any one of items a1 to a15;
The positioning device;
The warning device;
A work vehicle equipped with:

[Item b1]
A control system for a work vehicle that performs automatic steering operation,
A storage device that stores a target route for the work vehicle;
a control device that controls steering of the work vehicle so that the work vehicle travels along the target route based on the position of the work vehicle specified by the positioning device and the target route stored in the storage device;
Equipped with
the target route includes a plurality of parallel main routes and one or more turning routes connecting the plurality of main routes;
The control device changes a speed at which the work vehicle turns along the turning path by automatic steering in accordance with a curvature of the turning path.
Control system.

[Item b2]
The control system according to item b1, wherein the control device limits the speed at which the work vehicle turns along the turning path to a speed limit or less when a curvature of the turning path exceeds a reference value.

[Item b3]
The control system described in item b1 or b2, wherein when the work vehicle travels along one of the multiple main routes by automatic steering and reaches the start of a turning route connected to the main route or a point a predetermined distance before the start point, if the speed of the work vehicle exceeds a speed limit and the curvature of the turning route exceeds a reference value, the control device reduces the speed of the work vehicle to below the speed limit.

[Item b4]
The storage device further stores data defining a correspondence relationship between the curvature and the speed limit;
The control device determines the speed limit according to the curvature based on the data,
The larger the curvature, the lower the speed limit.
The control system according to item b2 or b3.

[Item b5]
The control system according to any one of items b2 to b4, wherein the control device repeatedly calculates a curvature of the turning path while the work vehicle is traveling, and changes the speed limit according to a rate of change of the curvature.

[Item b6]
The control device includes:
a cruise control function for causing the work vehicle to travel at a reference speed set by a user;
When the cruise control function is enabled, a speed at which the work vehicle turns along the turning path is changed in accordance with a curvature of the turning path.
A control system according to any one of items b1 to b5.

[Item b7]
When the cruise control function is enabled, the control device
causing the work vehicle to travel along one of the plurality of main routes at the reference speed;
turning the work vehicle along a turning path connected to the main path at a speed determined according to a curvature of the turning path;
After the turning, the work vehicle is caused to travel at the reference speed along another main route connected to the turning route.
The control system according to item b6.

[Item b8]
The control device includes:
A first control circuit for controlling steering of the work vehicle;
A second control circuit that controls a speed of the work vehicle;
The control system according to any of items b1 to b7, comprising:

[Item b9]
A control system described in any of items b1 to b8, wherein the control device, when the work vehicle enters a predetermined range including the turning path, causes a display device to display a pop-up notification indicating that the work vehicle has approached the turning path.

[Item b10]
The control system described in item b9, wherein the pop-up notification includes at least one piece of information: a turning direction, a distance and/or time to a starting point of the turn, whether or not to turn using automatic steering, and a speed during the turn.

[Item b11]
The control system according to any one of items b1 to b10, wherein the control device causes an audio output device to emit a warning sound when the work vehicle enters a predetermined range including the turning path.

[Item b12]
A control system described in any of items b1 to b11, wherein, when the control device limits the speed of the work vehicle based on the curvature of the turning path, the control device causes a display device to display information indicating that the speed is being limited.

[Item b13]
When the control device is controlling the speed of the work vehicle, the control device causes the display device to light up an indicator indicating that speed control is being performed,
When the speed of the work vehicle is limited based on the curvature of the turning path, the indicator is caused to flash to display the information indicating that the speed is limited.
The control system according to item b12.

[Item b14]
The plurality of main paths are located within a farm field,
The one or more turning paths are located on a headland of the field,
A control system according to any of items b1 to b13.

[Item b15]
A control system according to any one of items b1 to b14;
The positioning device;
A work vehicle equipped with:

[Item c1]
A control system for a work vehicle that performs automatic steering operation,
a storage device that stores a target route for the work vehicle and an operation sequence that defines a series of operations to be performed by the work vehicle when turning;
a control device that controls steering of the work vehicle so that the work vehicle travels along the target route based on the position of the work vehicle specified by the positioning device and the target route stored in the storage device;
Equipped with
the target route includes a plurality of parallel main routes and one or more turning routes connecting the plurality of main routes;
The control device includes:
When the work vehicle turns along the turning path by automatic steering, the work vehicle is caused to execute the series of operations in accordance with the operation sequence;
when a user performs an operation to instruct a turn while the work vehicle is traveling along one of the plurality of main routes by automatic steering, a pop-up is displayed on a display device in response to the operation, allowing the user to select whether or not to cause the work vehicle to execute the series of operations;
When it is selected to cause the work vehicle to execute the series of operations, the work vehicle is caused to execute a turn involving the series of operations in accordance with the operation sequence;
When it is selected that the work vehicle should not execute the series of operations, the work vehicle is caused to execute a turn that does not involve the series of operations.
Control system.

[Item c2]
The control device includes:
It is possible to switch between automatic and manual steering modes,
continuing the automatic steering mode even after causing the work vehicle to turn in response to the operation of the user instructing the turning;
The control system according to item c1.

[Item c3]
The control device includes:
a cruise control function for causing the work vehicle to travel at a reference speed set by a user;
and maintaining the cruise control function in an enabled state even after the work vehicle is caused to turn in response to the operation of the user instructing the work vehicle to turn while the cruise control function is enabled.
The control system according to item c1 or c2.

[Item c4]
the pop-up includes a display for allowing the user to set a rotation direction and a number of skipped columns,
The control device causes the work vehicle to turn in accordance with the set turning direction and the set number of skip rows.
A control system according to any one of items c1 to c3.

[Item c5]
The series of movements includes a first movement performed at the start of a turn and a second movement performed at the end of the turn,
the first operation includes at least one of the following operations: raising a work implement coupled to the work vehicle, stopping power output to the work implement, stopping a differential lock function of the work vehicle, switching from a two-wheel drive mode to a four-wheel drive mode, and reducing an engine speed of the work vehicle;
the second operation includes at least one operation of lowering the work machine, starting power output to the work machine, starting the differential lock function, switching from the four-wheel drive mode to the two-wheel drive mode, and increasing the engine speed.
A control system according to any one of items c1 to c4.

[Item c6]
the control device causes the display device to display a setting screen for allowing a user to set contents of the series of operations;
The control device stores the operation sequence based on the set content of the series of operations in the storage device.
A control system according to any one of items c1 to c5.

[Item c7]
The control device includes:
storing in the storage device an area in which work by the work vehicle has been completed;
When an operation for instructing the turning is performed by the user, a path for the turning is created;
When the route overlaps with the area in which the work has been completed, a warning is displayed on the display device.
A control system according to any of items c1 to c6.

[Item c8]
The control device includes:
When the warning is displayed on the display device, a user interface that allows the user to change the turning route is further displayed on the display device.
The control system according to item c7.

[Item c9]
The plurality of main paths are located within a farm field,
The one or more turning paths are located on a headland of the field,
A control system according to any of items c1 to c8.

[Item c10]
A control system according to any one of items c1 to c9;
The positioning device;
The display device;
A work vehicle equipped with:

[Item d1]
A control system for a work vehicle that performs automatic steering operation,
A storage device that stores a target route for the work vehicle;
a control device capable of switching between an automatic steering mode and a manual steering mode, and in the automatic steering mode, controlling steering of the work vehicle so that the work vehicle travels along the target route based on the position of the work vehicle identified by a positioning device and the target route stored in the storage device;
Equipped with
the target route includes a plurality of parallel main routes and one or more turning routes connecting the plurality of main routes;
When the work vehicle travels along one of the plurality of main routes and reaches a starting point of a turning route connected to the main route or a point a predetermined distance before the starting point, in the automatic steering mode, if the speed of the work vehicle exceeds a threshold value, the control device cancels the automatic steering mode and switches to the manual steering mode, and if the speed of the work vehicle does not exceed the threshold value, the control device continues the automatic steering mode and controls the steering of the work vehicle so that the work vehicle turns along the turning route.
Control system.

[Item d2]
The control system described in item d1, wherein when the control device continues the automatic steering mode and controls the steering of the work vehicle so that the work vehicle turns along the turning path, if the speed of the work vehicle exceeds the threshold value, the control device cancels the automatic steering mode and switches to the manual steering mode.

[Item d3]
The storage device further stores first data defining a correspondence relationship between a curvature of the turning path and the threshold value;
The control device determines the threshold value in accordance with a curvature of the turning path based on the first data,
The threshold value is smaller as the curvature of the turning path is larger.
The control system according to item d1 or d2.

[Item d4]
The storage device further stores second data defining a correspondence relationship between a curvature of the turning path and the predetermined distance;
The control device determines the predetermined distance in accordance with a curvature of the turning path based on the second data,
The greater the curvature of the turning path, the longer the predetermined distance.
A control system according to any one of items d1 to d3.

[Item d5]
the storage device further stores third data defining a correspondence relationship between a speed of the work vehicle and the predetermined distance;
The control device determines the predetermined distance according to a speed of the work vehicle traveling along one of the main routes based on the third data,
The higher the speed, the longer the predetermined distance.
A control system according to any one of items d1 to d3.

[Item d6]
The control device includes:
When the automatic steering mode is released and switched to the manual steering mode, the automatic steering mode is restored after turning in the manual steering mode is completed.
A control system according to any one of items d1 to d5.

[Item d7]
The control device includes:
After the turning in the manual steering mode is completed, a pop-up notification is displayed on a display device to prompt the user to decide whether or not to return to the automatic steering mode;
returning to the automatic steering mode in response to an operation by the user;
The control system according to item d6.

[Item d8]
The control device includes:
a cruise control function for causing the work vehicle to travel at a reference speed set by a user;
When the cruise control function is enabled, a determination is made as to whether the speed of the work vehicle exceeds the threshold value.
A control system according to any one of items d1 to d7.

[Item d9]
The control device includes:
When the automatic steering mode is released and switched to the manual steering mode while the cruise control function is enabled, after turning in the manual steering mode is completed, the automatic steering mode is returned to with the cruise control function enabled.
The control system according to item d8.

[Item d10]
A control system described in any of items d1 to d9, wherein the control circuit, when the work vehicle enters a predetermined range including the turning path, causes a display device to display a pop-up notification indicating that the work vehicle is approaching the turning path.

[Item d11]
The control system described in item d10, wherein the pop-up notification indicating that the work vehicle is approaching the turning path includes at least one piece of information: the turning direction, the distance and/or time to the start point of the turn, whether to turn in automatic steering mode, and the speed at which to turn.

[Item d12]
A control system described in any of items d1 to d11, wherein, when the control device switches from the automatic steering mode to the manual steering mode, the control device displays a pop-up notification on the display device indicating that the mode has been switched.

[Item d13]
The control system according to any one of items d1 to d12, wherein the control circuit causes an audio output device to emit a first warning sound when the work vehicle enters a predetermined range including the turning path.

[Item d14]
A control system described in any of items d1 to d13, wherein the control circuit causes an audio output device to emit a second warning sound when switching from the automatic steering mode to the manual steering mode.

[Item d15]
The plurality of main paths are located within a farm field,
The one or more turning paths are located on a headland of the field,
A control system according to any one of items d1 to d14.

[Item d16]
A control system according to any one of items d1 to d15;
The positioning device;
A work vehicle equipped with:

The technology disclosed herein can be applied to work vehicles used in agricultural applications, such as tractors, rice transplanters, combines, and harvesters. The technology disclosed herein can also be applied to work vehicles used in non-agricultural applications, such as construction vehicles or snowplows.

50 GNSS satellite 60 Reference station 70 Working area 80 Headland 81 Auto HMS trigger icon 82 Auto cruise control icon 85 Settings icon 86 Autosteer icon 87 On-demand turn icon 88, 89 Buttons 90, 91, 92, 93, 94, 95 Pop-up notification 96 Auto cruise indicator 97 Auto turn indicator 98, 99 Buttons 100 Work vehicle 101 Vehicle body 102 Prime mover (engine)
103 Transmission
104 Tire 105 Cabin 106 Steering device 107 Driver's seat 108 Coupling device 120 Positioning device 121 GNSS receiver 122 RTK receiver 125 Inertial measurement unit (IMU)
130 Obstacle sensor 140 Drive device 150 Steering wheel sensor 152 Turn angle sensor 160 Control system 170 Storage device 180 Control device 181, 182, 183, 184, 185, 186 ECU
190 Communication interface 200 Operation terminal 210 Operation switch group 220 Buzzer 300 Work machine 340 Driving device 360 Control device 390 Communication interface

Claims (16)

A control system for a work vehicle that performs automatic steering operation,
A storage device that stores a target route for the work vehicle;
a control device capable of switching between an automatic steering mode and a manual steering mode, and in the automatic steering mode, controlling steering of the work vehicle so that the work vehicle travels along the target route based on the position of the work vehicle identified by a positioning device and the target route stored in the storage device;
Equipped with
the target route includes a plurality of parallel main routes and one or more turning routes connecting the plurality of main routes;
When the work vehicle travels along one of the plurality of main routes and reaches a starting point of a turning route connected to the main route or a point a predetermined distance before the starting point, in the automatic steering mode, if the speed of the work vehicle exceeds a threshold value, the control device cancels the automatic steering mode and switches to the manual steering mode, and if the speed of the work vehicle does not exceed the threshold value, the control device continues the automatic steering mode and controls the steering of the work vehicle so that the work vehicle turns along the turning route.
Control system. The control system according to claim 1, wherein when the automatic steering mode is continued and the steering of the work vehicle is controlled so that the work vehicle turns along the turning path, if the speed of the work vehicle exceeds the threshold value, the control device cancels the automatic steering mode and switches to the manual steering mode. The storage device further stores first data defining a correspondence relationship between a curvature of the turning path and the threshold value;
The control device determines the threshold value in accordance with a curvature of the turning path based on the first data,
The threshold value is smaller as the curvature of the turning path is larger.
A control system according to claim 1 or 2. The storage device further stores second data defining a correspondence relationship between a curvature of the turning path and the predetermined distance;
The control device determines the predetermined distance in accordance with a curvature of the turning path based on the second data,
The greater the curvature of the turning path, the longer the predetermined distance.
A control system according to any one of claims 1 to 3. the storage device further stores third data defining a correspondence relationship between a speed of the work vehicle and the predetermined distance;
The control device determines the predetermined distance according to a speed of the work vehicle traveling along one of the main routes based on the third data,
The higher the speed, the longer the predetermined distance.
A control system according to any one of claims 1 to 3. The control device includes:
When the automatic steering mode is released and switched to the manual steering mode, the automatic steering mode is restored after turning in the manual steering mode is completed.
A control system according to any one of claims 1 to 5. The control device includes:
After the turning in the manual steering mode is completed, a pop-up notification is displayed on a display device to allow a user to confirm whether or not to return to the automatic steering mode;
returning to the automatic steering mode in response to an operation by the user;
7. The control system of claim 6. The control device includes:
a cruise control function for causing the work vehicle to travel at a reference speed set by a user;
When the cruise control function is enabled, a determination is made as to whether the speed of the work vehicle exceeds the threshold value.
A control system according to any one of claims 1 to 7. The control device includes:
When the automatic steering mode is released and switched to the manual steering mode while the cruise control function is enabled, after turning in the manual steering mode is completed, the automatic steering mode is returned to with the cruise control function enabled.
9. The control system of claim 8. 10. The control system according to claim 1, wherein the control device , when the work vehicle enters a predetermined range including the turning path, causes a display device to display a pop-up notification indicating that the work vehicle has approached the turning path. The control system according to claim 10, wherein the pop-up notification indicating that the work vehicle is approaching the turning path includes at least one piece of information regarding the turning direction, the distance and/or time to the turning start point, whether or not to turn in automatic steering mode, and the speed during the turn. The control system according to any one of claims 1 to 11, wherein when the control device switches from the automatic steering mode to the manual steering mode, the control device causes the display device to display a pop-up notification indicating that the mode has been switched. 13. The control system according to claim 1, wherein the control device causes an audio output device to emit a first warning sound when the work vehicle enters a predetermined range including the turning path. The control system according to claim 1 , wherein the control device causes an audio output device to emit a second warning sound when switching from the automatic steering mode to the manual steering mode. The plurality of main paths are located within a farm field,
The one or more turning paths are located on a headland of the field,
A control system according to any preceding claim. A control system according to any one of claims 1 to 15;
The positioning device;
A work vehicle equipped with:

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