Tractor

Abstract

To provide a tractor that allows a start point and an end point to be set by a simple operation when calculating a target azimuth.SOLUTION: A tractor includes: a machine body equipped with a travelling device; a position detection part capable of detecting position information on the machine body on the basis of a positioning signal of a navigation satellite; a travelling trajectory acquisition unit capable of acquiring a travelling trajectory of the machine body on the basis of the detection with time of the position information; a target azimuth calculation unit for calculating a target azimuth on the basis of the travelling trajectory; a steering control unit capable of executing steering control for the travelling device along the target azimuth; and an operation tool capable of setting a start point and an end point of the travelling trajectory acquired when calculating the target azimuth.SELECTED DRAWING: Figure 6

Description

[Technical field]

[0001] The present invention relates to a tractor. [Background technology]

[0002] For example, the work vehicle disclosed in Patent Document 1 is equipped with a position detection unit (referred to as a "receiving device" in the document) that can obtain position information on the vehicle using a satellite positioning system, and a steering control unit (referred to as an "automatic steering control unit" in the document) that can control the steering of the vehicle along a target orientation based on the position information obtained by the position detection unit. In addition, the target orientation that serves as the basis for the automatic steering control is set based on the positions of an operating tool that registers a start point (referred to as a "start point registration switch" in the document) and an operating tool that registers an end point (referred to as an "end point registration switch" in the document) when each of these is operated. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2018-148858 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the work vehicle disclosed in Patent Document 1, the start point and the end point are registered using separate and dedicated operating tools. With this configuration, there is a risk that the occupant will press the wrong operating tool when registering the start point and the end point, and in that case, the operation of registering the start point and the end point becomes troublesome for the occupant. Furthermore, if the operating tool is configured to be used as another operating means in addition to setting the start point and the end point, the number of operating tools can be reduced, which is advantageous in terms of cost.

[0005] An object of the present invention is to provide a tractor that enables the setting of a start point and an end point when calculating a target orientation with a simple operation. [Means for solving the problem]

[0006] A tractor according to the present invention comprises a vehicle equipped with a traveling device, a position detection unit capable of detecting position information of the vehicle based on a positioning signal of a navigation satellite, a traveling track acquisition unit capable of acquiring a traveling track of the vehicle based on detection of the position information over time, a target orientation calculation unit calculating a target orientation based on the traveling track, a target generation route setting unit generating a target traveling route based on the target orientation, a steering control unit capable of steering control of the traveling device along the target traveling route, an operating tool capable of setting a start point and an end point of the traveling track acquired when calculating the target orientation, and a display unit capable of displaying information relating to setting of the target orientation, wherein the target orientation calculation unit is configured such that the start point is set by operating the operating tool, and that after the vehicle has traveled a predetermined distance after setting the start point, it becomes possible to set the end point by operating the operating tool, and the display unit displays information indicating that the end point cannot be set if the traveling distance of the vehicle after the start point is set by operating the operating tool does not reach a predetermined distance or more. The display unit displays a symbol indicating the start point and a symbol indicating the end point, and a display mode of the symbol indicating the start point and the symbol indicating the end point changes before and after the start point is set. It is characterized by: In the above configuration, when the distance traveled by the aircraft after the start point is set has not reached a predetermined distance and the operating tool is operated, it is preferable that the display unit displays information indicating that the end point cannot be set. In the above configuration, it is preferable that when the travel distance exceeds a predetermined distance, the end point can be set by operating the operating tool. In addition, the mobile work machine according to the present invention is characterized in that it is equipped with a position detection unit capable of detecting position information of the machine based on a positioning signal of a navigation satellite, a traveling trajectory acquisition unit capable of acquiring the traveling trajectory of the machine based on detection of the position information over time, a target orientation calculation unit that calculates a target orientation based on the traveling trajectory, a steering control unit that is capable of steering control of the machine along the target orientation, and one operating tool that can set both the start point and the end point of the traveling trajectory acquired when calculating the target orientation.

[0007] According to the present invention, the start point and the end point can be set with one operating tool. Therefore, compared to a configuration in which separate operating tools are provided for registering the start point and the end point, the risk of the rider pressing the wrong operating tool is reduced, and the operation of registering the start point and the end point is simplified. Furthermore, by using this one operating tool as multiple operating means, the number of operating tools is reduced, which is advantageous in terms of cost. This realizes a traveling work machine that allows the setting of the start point and the end point when calculating the target orientation with a simple operation.

[0008] In the present invention, it is preferable that the target orientation calculation unit is configured so that the start point is set by operating the operating tool, and that after the aircraft has traveled a predetermined distance after the start point is set, the end point can be set by operating the operating tool.

[0009] With this configuration, the aircraft always runs after the start point is set, making it possible to set the end point at a position different from the start point. Also, with this configuration, by setting the distance between the start point and the end point to a preset distance or more, it becomes possible to calculate the target direction with a predetermined accuracy or higher.

[0010] In the present invention, a display unit capable of displaying information relating to the setting of the target orientation is provided, and when it becomes possible to set the end point by operating the operating tool, it is preferable that the display unit displays that it is possible to set the end point.

[0011] With this configuration, even if the passenger does not know how to set the target heading, the passenger can set the start point and the end point while checking the information displayed on the display unit. This makes it even easier to set the start point and the end point when calculating the target heading.

[0012] In the present invention, it is preferable that the target orientation calculation unit is configured to enable setting of the starting point by operating the operating tool when the accuracy of the acquisition of the position information by the position detection unit is equal to or higher than a predetermined accuracy.

[0013] If the accuracy of the position information is poor when setting the start point and the end point, there is a risk that the target direction cannot be calculated accurately. With this configuration, if the accuracy of the position information is poor, it is impossible to set the start point, so the risk of steering control being performed based on an incorrect target direction is avoided.

[0014] In the present invention, it is preferable that a steering operation detection means is provided for detecting a steering operation of the aircraft, and after the starting point is set by operating the operating tool, if a change in the steering operation is detected to exceed a predetermined range without the operating tool being operated, the setting of the starting point is canceled.

[0015] When the travel path is in a turning state, the target orientation is not calculated along the travel path, and there is a risk that the steering control as intended by the passenger will not be realized. With this configuration, it is possible to determine the turning of the aircraft based on the amount of change in the steering operation, and it is possible to avoid setting the start point and the end point when the travel path is in a turning state.

[0016] In the present invention, the vehicle is provided with a boarding section on which a passenger boards, and a steering operation device that is supported by a support member in the boarding section and can steer the traveling device, and it is preferable that the operation device is arranged above the support member and directly below the steering operation device.

[0017] With this configuration, the support member for supporting the steering operation tool also serves as a support member for the operation tool, making it possible to support the operation tool with a simple support configuration. In addition, it becomes easier for the passenger to operate the operation tool while operating the steering operation tool, and the operation of registering the start point and the end point becomes even easier. [Brief description of the drawings]

[0018] [Figure 1] FIG. 2 is a side view of a tractor serving as a traveling work machine. [Diagram 2] FIG. 4 is a diagram showing panels at the front part of the inside of the cab. [Diagram 3] FIG. 2 is a functional block diagram showing the functions and data flow of automatic steering control. [Figure 4]FIG. 2 is a plan view of a farm field, showing a typical travel path during tilling work by a tractor. [Diagram 5] FIG. 11 is a flowchart showing a process for generating a reference trajectory. [Figure 6] FIG. 11 is an explanatory diagram showing guidance information when generating a reference route. [Figure 7] FIG. 11 is a flowchart showing a process for displaying guidance information during turning. [Figure 8] FIG. 11 is an explanatory diagram showing guidance information when turning; [Figure 9] FIG. 11 is an explanatory diagram showing guidance information when turning; [Figure 10] FIG. 11 is an explanatory diagram showing guidance information when turning; [Figure 11] FIG. 11 is an explanatory diagram showing guidance information when turning; [Figure 12] FIG. 11 is a flowchart showing a process for displaying guidance information before automatic steering control is started. [Figure 13] FIG. 4 is an explanatory diagram showing guidance information before automatic steering control is started. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] [Basic configuration of traveling work machine] An embodiment of the traveling work machine according to the present invention will be described. FIG. 1 shows a side view of a tractor, which is an example of the traveling work machine. In this tractor, a riding section 15 is provided in the center of a machine body 1 supported by front wheels 11 and rear wheels 12 as a traveling device. A rotary type tiller 3 as a working device is mounted on the rear of the machine body 1 via a hydraulic lifting mechanism. The front wheels 11 function as steering wheels, and the traveling direction of the tractor is changed by changing the steering angle. The steering angle of the front wheels 11 is changed by the operation of a steering mechanism 13. The steering mechanism 13 includes a steering motor 14 for automatic steering control. A panel assembly 17 is provided in the front part inside the riding section 15, and a steering wheel 16 as a steering operation tool is arranged adjacent to the rear of the panel assembly 17. Although not described in detail, a recess is provided in the left and right central part of the rear part of the panel assembly 17, and the recess is recessed toward the front of the machine body from the left and right sides of the panel assembly 17. The steering wheel 16 is supported by a steering post 22 serving as a support member, and the front part of the vehicle body of the steering post 22 is located in a recessed portion. When the vehicle is driven manually, the front wheels 11 are steered by manually operating the steering wheel 16.

[0020] In addition, in the present invention, "steering operation" refers to changing the direction of the body 1 by changing the direction of the front wheels 11, but if the running gear is a crawler type, changing the direction of the body 1 by the speed difference between the left and right crawlers is also included in "steering operation".

[0021] 2, the panel assembly 17 is provided with a meter panel 20 and a side panel 21 arranged vertically, with the side panel 21 being disposed above the meter panel 20. The meter panel 20 displays information relating to the operation of the vehicle 1, such as the engine RPM and remaining fuel level. The side panel 21 displays guidance information for the automatic steering control, which will be described later. The meter panel 20 and the side panel 21 are configured as part of the display unit 4 in the configuration for the automatic steering control.

[0022] A dial switch 23 is disposed on the upper surface of the steering post 22. The side panel 21 is configured to be operable by the dial switch 23 as an operating tool, and the dial switch 23 is disposed on the upper part of the steering post 22 and directly below the steering wheel 16. The dial switch 23 is configured to be freely rotatable about an axis in the vertical direction (or in a direction inclined upward toward the rear in the longitudinal direction of the aircraft), and the passenger can switch the items of the guidance information displayed on the side panel 21 by turning the dial switch 23. The dial switch 23 is also configured to be pressed downward (or in a direction inclined downward toward the front in the longitudinal direction of the aircraft). The passenger can confirm the setting items and selection items related to the guidance information displayed on the side panel 21 by pressing the dial switch 23. The dial switch 23 also serves as a trigger switch 49, which will be described later with reference to FIG. 3 and the like, and is operated as the trigger switch 49 by the passenger pressing the dial switch 23. Hereinafter, the dial switch 23 will be referred to as the "trigger switch 49."

[0023] [Configuration of automatic steering control] Next, the configuration for performing automatic steering control will be described. As shown in Fig. 3, the vehicle 1 is equipped with a control device 75 consisting of a number of electronic control units called ECUs (electronic control units). The control device 75 is configured to be able to switch the control mode between an automatic steering mode in which automatic steering control is performed, and a manual steering mode in which automatic steering control is not performed.

[0024] The aircraft 1 is equipped with a satellite positioning unit 8a that uses a well-known technology, GPS (Global Positioning System), as an example of a satellite positioning system (GNSS: Global Navigation Satellite System) that receives radio waves from satellites to detect the position of the aircraft 1. In this embodiment, the satellite positioning unit 8a uses DGPS (Differential GPS: relative positioning method), but it is also possible to use RTK-GPS (Real Time Kinematic GPS: interferometric positioning method).

[0025] Specifically, the aircraft 1, which is the object of positioning, is provided with a satellite positioning unit 8a, which is one component of the position detection unit 8. The satellite positioning unit 8a receives, via an antenna, radio waves transmitted from a plurality of GPS satellites orbiting the Earth. The position of the satellite positioning unit 8a is determined based on information on the radio waves received from the navigation satellites.

[0026] In addition to the satellite positioning unit 8a, the airframe 1 is provided with an inertial measurement unit 8b having, for example, an IMU (Inertial Measurement Unit) as an orientation detection means for detecting the orientation of the airframe 1. The inertial measurement unit 8b may be configured to include a three-axis gyro sensor or a three-axis acceleration sensor. Although not shown, the inertial measurement unit 8b is provided, for example, at a low position in the center of the width direction of the airframe 1. The inertial measurement unit 8b can detect the angular velocity of the turning angle of the airframe 1, and can calculate the change in the azimuth angle of the airframe 1 by integrating the angular velocity. Therefore, the measurement information measured by the inertial measurement unit 8b includes the orientation information of the airframe 1. Although not described in detail, the inertial measurement unit 8b can measure the angular velocity of the turning angle of the airframe 1, the left and right tilt angle of the airframe 1, the forward and backward tilt angle of the airframe 1, and the like.

[0027] The control device 75 has a route setting unit 76, an orientation deviation calculation unit 77, a travel trajectory acquisition unit 78, a control unit 79, and a steering control unit 80. The route setting unit 76 sets a target travel route LM (see FIG. 4, FIG. 8, etc.) along which the vehicle 1 should travel. The orientation deviation calculation unit 77 is configured to be able to calculate an angle deviation between the travel orientation of the vehicle 1 and the target orientation LA, that is, an orientation deviation. The control unit 79 calculates and outputs an operation amount based on the orientation deviation information so that the vehicle 1 travels along the target travel route LM. Note that the control unit 79 can also calculate and output an operation amount based on the position information of the vehicle 1 measured by the satellite positioning unit 8a and the orientation information of the vehicle 1 measured by the inertial measurement unit 8b, in addition to the orientation deviation information. The steering control unit 80 controls the steering motor 14 based on the operation amount. Note that the control unit 79 and the steering control unit 80 may be configured integrally.

[0028] A trigger switch 49 is provided as an operating tool for setting a target travel path LM (see Figs. 4, 8, etc.) used for automatic steering control and starting automatic steering control. Although details will be described later, the target travel path LM is set based on a target orientation LA (see Fig. 4), which is calculated based on a travel path that the machine body 1 has traveled in a farm field in advance. Setting of a start position Ts (see Fig. 4) and an end position Tf (see Fig. 4) in travel for obtaining the travel path are performed by operating the trigger switch 49. Note that the trigger switch 49 does not have to be composed of a single switch, and may be configured to include a switch for setting the start position Ts and a switch for setting the end position Tf, each of which is provided side by side.

[0029] Information from the satellite positioning unit 8a, the inertial measurement unit 8b, the trigger switch 49 as an operating tool, the steering angle sensor 60 as a steering operation detection means, the torque sensor 61, the vehicle speed sensor 62, the obstacle detection unit 63, and the like is input to the control device 75. The vehicle speed sensor 62 is configured to detect the vehicle speed from the rotation speed of the transmission shaft in the transmission mechanism for the rear wheels 12, for example. The vehicle speed may be detected not only by the vehicle speed sensor 62 but also by the positioning signal of the satellite positioning unit 8a. The obstacle detection unit 63 is provided at the front and both left and right sides of the vehicle body 1, and is configured to be, for example, a light wave distance measuring type distance sensor or an image sensor, and is configured to be able to detect the edge of the field, a steel tower in the field, and the like. When an obstacle is detected by the obstacle detection unit 63, an alarm is issued to the passenger by the alarm unit 64, which is, for example, a buzzer or a voice guide. The control device 75 is connected to the notification unit 59, and the notification unit 59 is configured to notify the vehicle speed, engine speed, and other conditions. The notification unit 59 is configured to be displayed on the display unit 4, for example. The alarm unit 64 may be configured to display an alarm on the display unit 4 via the notification unit 59. In this case, for example, an alarm for edge detection is displayed on the display unit 4. The alarm unit 64 may be configured as a part of the notification unit 59. The display unit 4 is configured to be able to display various information on the screen based on signal input from the notification unit 59 and the alarm unit 64. The display unit 4 is configured to be able to display various types of guidance information according to the straight running status, turning running status, and the like of the machine body 1.

[0030] The azimuth deviation calculation unit 77 calculates the angular deviation between the detected azimuth of the vehicle 1 detected by the satellite positioning unit 8a and the inertial measurement unit 8b and the target azimuth LA on the target driving route LM, i.e., the azimuth deviation. When the control device 75 is set to the automatic steering mode, the control unit 79 calculates and outputs an operation amount for controlling the steering motor 14 so as to reduce the angular deviation. In this way, the steering control unit 80 is configured to be able to steer and control the vehicle 1 along the target azimuth LA.

[0031] The travel trajectory acquisition unit 78 calculates the position of the aircraft 1, that is, the aircraft's own position NM, based on the positioning signal measured by the satellite positioning unit 8a, the orientation of the aircraft 1 calculated by the orientation deviation calculation unit 77, and the vehicle speed detected by the vehicle speed sensor 62. The storage unit 81 is configured to be able to store the aircraft's own position NM as position information. The travel trajectory acquisition unit 78 stores the aircraft's own position NM over time in the storage unit 81, which is configured of, for example, a RAM (random access memory). The travel trajectory acquisition unit 78 is also configured to be able to acquire a travel trajectory based on a set of the aircraft's own positions NM stored in the storage unit 81. In short, the travel trajectory acquisition unit 78 is configured to be able to acquire the travel trajectory of the aircraft 1 based on the detection of the aircraft's own position NM over time as position information.

[0032] Based on the azimuth deviation information, the control unit 79 calculates the amount of operation. During automatic steering control of the aircraft 1, the steering control unit 80 executes automatic steering control based on the amount of operation output by the control unit 79. That is, the steering motor 14 is operated so that the detected position of the aircraft 1 (aircraft position NM) detected by the satellite positioning unit 8a and the inertial measurement unit 8b becomes a position on the target driving route LM.

[0033] The control signal in this embodiment may be an amount of operation output by the control unit 79, or may be a voltage value or a current value for the steering control unit 80 to operate the steering motor 14.

[0034] The route setting unit 76 includes a reference route setting unit 76A, a target orientation calculation unit 76B, and a target driving route setting unit 76C. As shown in FIG. 3, a reference route corresponding to a target route to be automatically steered is set by the reference route setting unit 76A through a reference route setting process based on the operation of the trigger switch 49. The target orientation calculation unit 76B calculates a target orientation LA based on an orientation along the longitudinal direction of the reference route. The target driving route setting unit 76C is configured to be able to generate a target driving route LM along the target orientation LA based on the reference route and the target orientation LA. In order to generate the target driving route LM, the route setting unit 76 includes a start position calculation unit 76D, an end determination unit 76E, and a distance calculation unit 76F. The start position calculation unit 76D, the end determination unit 76E, and the distance calculation unit 76F will be described later. The reference route setting unit 76A and the target orientation calculation unit 76B may be configured integrally.

[0035] [Target driving route] FIG. 4 shows a schematic diagram of an example of tilling work by a tractor. In this tilling work, a work run that advances along a linear work path accompanied by actual tilling work and a turning run that turns to move to the next linear work path are repeated multiple times alternately. In this case, the first linear work path is a reference path that is manually steered, and the subsequent linear paths are set by the path setting unit 76 to be parallel to the reference path in sequence. These paths are target travel paths LM for automatic steering control, and FIG. 4 shows multiple target travel paths LM1 to LM6. Work travel accompanied by automatic steering control is performed on each of the target travel paths LM1 to LM6. When the machine body 1 travels between each of the target travel paths LM1 to LM6, it moves from the end position Lf of the work run to the start position Ls of the next work run in an unworked area of ​​the field while reversing in the opposite direction to the advancing direction of the work run.

[0036] First, a reference path is generated. The rider manually moves the machine body 1 to a ridge at one corner of the field. When the machine body 1 reaches the ridge at one corner, the rider operates the trigger switch 49. The position at which the rider operates the trigger switch 49 is registered as the starting point position Ts by the reference path setting unit 76A. After the starting point position Ts is registered, the rider manually moves the machine body 1 straight (or approximately straight) from the starting point position Ts along the ridge at one side of the field. During this time, the traveling trajectory acquisition unit 78 calculates the machine body position NM over time and stores it in the memory unit 81. Then, after the machine body 1 moves straight (or approximately straight) from one end of the ridge at one side to the other end, the rider stops the machine body 1 and operates the trigger switch 49 again. Then, the position at which the rider operates the trigger switch 49 again is registered as the end point position Tf by the reference path setting unit 76A. The travel trajectory acquisition unit 78 acquires a travel trajectory based on a set of the aircraft's positions NM between the start position Ts and the end position Tf, and the reference path setting unit 76A calculates a reference path between the start position Ts and the end position Tf based on the travel trajectory. When the aircraft 1 travels along the target travel path LM, the direction along the reference path becomes the target orientation LA.

[0037] In addition, the traveling of the machine body 1 between the start position Ts and the end position Tf may be a work traveling accompanied by tilling work, or may be a non-work traveling. When the position coordinates of the reference route are set, it is also possible to perform automatic steering control on at least a part of this reference route.

[0038] After completing the setting of the reference path, the rider moves the machine 1 to the start position Ls of the target area of ​​the first work run in the field. In the embodiment shown in FIG. 4, since the target area of ​​the first work run is adjacent to the reference path, the rider performs a turning run in which the traveling direction of the machine 1 is reversed by 180 degrees in order to move the machine 1 to the start position Ls. At this time, the control unit 79 can determine that the machine 1 has turned by the reversal of the orientation of the machine 1. The reversal of the orientation of the machine 1 can be detected by the satellite positioning unit 8a or the inertial measurement unit 8b. The turning of the machine 1 may be determined by the operation of various devices other than the reversal of the orientation of the machine 1. As the operation of various devices, for example, a configuration in which the clutch of the PTO shaft is turned on and off may be used. In addition, the arrival of the machine 1 at the start position Ls may be determined by the satellite positioning unit 8a.

[0039] After the turning is completed, the manual steering mode of the control device 75 continues, and the rider manually drives the vehicle 1 along the target direction LA. During this time, the control device 75 checks the direction deviation of the vehicle 1 calculated by the direction deviation calculation unit 77, the direction of the front wheels 11, the steering angle of the steering wheel 16, and other discrimination conditions, and judges whether the state of the vehicle 1 is suitable for the next tilling work. Whether the state of the vehicle 1 is suitable for tilling work is judged, for example, based on whether the running deviation in the left-right direction of the vehicle 1 relative to a reference position that is an integer multiple of the working width away from the position before the turning in a direction perpendicular to the target direction LA is within an allowable range. If the running deviation is outside the allowable range, the rider manually steers the vehicle 1 so that the running deviation of the vehicle 1 is within the allowable range.

[0040] Examples of conditions that are not suitable for tilling work include a significantly large azimuth deviation of the machine body 1 from the target azimuth LA, the steering wheel 16 being continuously steered left and right so that the position of the steering wheel 16 is not stable, the vehicle speed of the machine body 1 being too fast or too slow, etc. Another example of a condition that is not suitable for tilling work is when the detection accuracy of the position detection unit 8 is lower than a preset threshold value.

[0041] When the control device 75 determines that the state of the machine body 1 is suitable for the next tilling work, automatic steering control is possible by operating the trigger switch 49. That is, when the rider operates the trigger switch 49, the target travel route LM1 is set by the target travel route setting unit 76C, and work travel is started. When work travel is started, automatic steering control is performed so that the machine body 1 travels along the target travel route LM1. The target travel route LM1 is set in a direction along the target orientation LA, and is the target travel route LM along which the machine body 1 first travels for work after the reference route is set. During the automatic steering control, automatic steering is performed by the operation of the steering mechanism 13, and the vehicle speed of the machine body 1 is also automatically adjusted. Note that even during the automatic steering control, the vehicle speed of the machine body 1 may be configured to be adjusted by manual operation of the rider.

[0042] When the automatic steering control along the target travel path LM1 is completed, the rider continues manual steering until the state of the machine body 1 becomes suitable for the next tilling work after the above-mentioned turning travel. If the operation of the trigger switch 49 is permitted, the rider operates the trigger switch 49, and the target travel path setting unit 76C sets the next target travel path LM2 in a direction along the target orientation LA. Then, automatic steering control is performed so that the machine body 1 travels along the target travel path LM2. After that, in the above-mentioned process, turning travel, setting of the target travel path LM, and work travel are repeated in the order of the target travel paths LM3, LM4, LM5, and LM6.

[0043] [Display of guidance information regarding reference route generation] The display of guidance information regarding the reference path generation will be described with reference to Figs. 3, 5 and 6. The reference path setting unit 76A generates a reference path based on the flowchart shown in Fig. 5. Before generating the reference path, the path setting unit 76 judges whether the position detection unit 8 can detect the position information of the machine body 1 (step #01). If the position information of the machine body 1 is not detected (step #01: No), a message indicating that it is not detectable is displayed on the display unit 4 (step #02), and the reference path is not generated. In this way, when the accuracy of the acquisition of position information by the position detection unit 8 is equal to or higher than a preset accuracy, the reference path setting unit 76A enables the setting of the start position Ts by operating the trigger switch 49 as an operating tool.

[0044] If the position information of the machine 1 is detected (step #01: Yes), guidance information of the starting point position Ts as shown in 6-A of FIG. 6 is displayed on the display unit 4 (step #03), and the starting point position Ts can be registered. The guidance information shown in 6-A, 6-B, and 6-C of FIG. 6 is displayed on the side panel 21 shown in FIG. 2. Note that this guidance information may be displayed on the meter panel 20 shown in FIG. 2. In the guidance information of the starting point position Ts shown in 6-A of FIG. 6, the starting point position Ts is displayed as "Start Point A". With the guidance information of the starting point position Ts displayed on the display unit 4, the operation of the trigger switch 49 is awaited (step #04). When the trigger switch 49 is operated (step #04: Yes), the reference path setting unit 76A registers the starting point position Ts (start point A) (step #05).

[0045] After the start position Ts is registered, the passenger moves the vehicle 1 in a straight line by manual operation. The reference path setting unit 76A then determines whether the vehicle 1 has traveled a preset distance or more by calculating the distance between the start position Ts and the vehicle's own position NM over time (step #06). If the travel distance of the vehicle 1 has not reached the set distance (step #06: No), guidance information indicating that the travel distance has not reached the set distance is displayed on the display unit 4 even if the passenger operates the trigger switch 49. As guidance information indicating that the travel distance has not reached the set distance, for example, a message such as "straight distance is insufficient" is displayed as shown in 6-B of FIG. 6. In this way, the reference path setting unit 76A sets the start position Ts (start point A) by operating the trigger switch 49 as an operating tool, and after the vehicle 1 has traveled a preset distance after the start position Ts is set, the reference path setting unit 76A can set the end position Tf (end point B) by operating the trigger switch 49.

[0046] While the aircraft 1 is moving straight by manual operation, the reference path setting unit 76A also determines whether the aircraft 1 is turning (step #07). The steering angle sensor 60 detects the amount of change in steering based on the operation of the steering wheel 16. The aircraft 1 is configured to be able to determine the turning of the aircraft 1 when the amount of change in steering based on the detection of the steering angle sensor 60 is detected to exceed a preset range. The azimuth deviation calculation unit 77 can calculate the turning azimuth of the aircraft 1 based on the positioning signal of the satellite positioning unit 8a and the inertial signal of the inertial measurement unit 8b. Then, when the reference path setting unit 76A determines that the aircraft 1 is turning (step #07: Yes), the registration of the start position Ts is cancelled and the generation of the reference path is stopped (step #12). At this time, the display unit 4 displays guidance information indicating that the generation of the reference path has been stopped, for example, a message saying "The generation of the reference path is terminated because a turn has been detected. Please start the generation of the reference path again." In this way, after the start position Ts (start point A) is set by operating the trigger switch 49 as an operating tool, if a change in steering operation is detected to exceed a preset range without the trigger switch 49 being operated, the setting of the start position Ts is canceled.

[0047] If the travel distance of the machine 1 has reached the set distance (step #06: Yes), guidance information for the end position Tf as shown in 6-C of FIG. 6 is displayed on the display unit 4 (step #08), and the end position Tf can be registered. In the guidance information for the end position Tf shown in 6-C of FIG. 6, the end position Tf is displayed as "end point B." With the guidance information for the end position Tf displayed on the display unit 4, the operation of the trigger switch 49 is awaited (step #09). In this way, when it becomes possible to set the end position Tf (end point B) by operating the trigger switch 49 as an operating tool, the display unit 4 displays that it is possible to set the end position Tf.

[0048] When the trigger switch 49 is operated (step #09: Yes), the reference path setting unit 76A registers the end position Tf (step #11). Through the above steps, the reference path is generated and the target orientation LA is calculated. In this manner, the reference path setting unit 76A sets the reference path based on the travel trajectory of the aircraft 1. In addition, the trigger switch 49 as an operating tool is configured to be able to set both the start position Ts (start point A) and the end position Tf (end point B) when setting the reference path.

[0049] While waiting for the operation of the trigger switch 49 (step #09: No), the reference path setting unit 76A determines whether the aircraft 1 is turning (step #11) using the same method as in step #07. If it is determined that the aircraft 1 is turning (step #11: Yes), as described above, the registration of the start position Ts is cancelled and the generation of the reference path is stopped (step #12), and guidance information to the effect that the generation of the reference path has been stopped is displayed on the display unit 4.

[0050] [Display of guidance information when turning] The display of guidance information in turning will be described with reference to FIG. 7 and FIG. 11. As shown in FIG. 8, when turning is performed after automatic steering control along the target driving route LM is completed, guidance information regarding turning is displayed on the display unit 4. Guidance information for turning left shown in 8-A of FIG. 8 and FIG. 9 is displayed on the display unit 4 after automatic driving control is performed along the target driving route LM[n-1]. Also, guidance information for turning right shown in 8-B of FIG. 8 and FIG. 9 is displayed on the display unit 4 after automatic driving control is performed along the target driving route LM[n]. These pieces of guidance information include a map screen that displays the machine body 1 and the surroundings of the machine body 1. Also, these pieces of guidance information are displayed on the side panel 21 shown in FIG. 2, but may be displayed on the meter panel 20 shown in the same figure.

[0051] As shown in Fig. 3, the route setting unit 76 includes a start position calculation unit 76D, an end determination unit 76E, and a distance calculation unit 76F. Fig. 7 shows a flowchart relating to the display of guidance information relating to turning, and the control device 75 performs processing based on this flowchart.

[0052] The end determination unit 76E determines whether the automatic steering control for traveling along the target travel path LM has ended (step #21). The end of the automatic steering control is determined by, for example, whether the PTO clutch lever (not shown) or the pump lever (not shown) has been operated. If the end of the automatic steering control is determined by the end determination unit 76E (step #21: Yes), the vehicle position NM at the time when the end of the automatic steering control is determined is stored in the storage unit 81 as the end position Lf (step #22). The end position Lf is used as the work travel position information WP for the start position calculation unit 76D to calculate the start position Ls2 of the next work travel. Among the end positions Lf shown in Figs. 8 to 11, the end position Lf of the target travel path LM[n] is also shown as the work travel position information WP for calculating the start position Ls2 of the next work travel. In this specification, the start position Ls2 is described separately from the start position Ls as the one to be calculated by the start position calculation unit 76D.

[0053] The memory unit 81 stores information about the previous turning. The start position calculation unit 76D is configured to be able to determine whether the previous turning was a right turn or a left turn by reading data about the turning from the memory unit 81. As shown in FIG. 4, when the machine body 1 repeats automatic steering control along the target direction LA, turning at the edge of a field generally alternates between right turns and left turns. For this reason, the start position calculation unit 76D determines whether the previous turning was a right turn or a left turn (step #23). The determination in step #23 may be performed by a module other than the start position calculation unit 76D. If the previous turning was a right turn (step #23: turn right), before the machine 1 starts turning, the start position calculation unit 76D calculates the next start position Ls2 on the left turning side based on the previous turning (step #25-1). Then, the display unit 4 displays guidance information for a left turn (step #25-2), and the display line L2 based on the start position Ls2 is also displayed on this guidance information. If the previous turn was a left turn (step #23: turn left), the start position calculation unit 76D calculates the next start position Ls2 on the right turn side based on the previous turn before the machine body 1 starts turning (step #24-1). Then, the display unit 4 displays guidance information for a right turn (step #24-2), and the display line L2 based on the start position Ls2 is also displayed on this guidance information.

[0054] In this way, when the end determination unit 76E determines the end of the work run, the start position calculation unit 76D calculates the start position Ls2 to either the left or right with respect to the traveling direction of the machine body 1 in the work run based on the work run position information WP as position information, and the display unit 4 displays guidance information that guides the turning run to the start position Ls2. At that time, if the start position calculation unit 76D calculated the start position Ls in the turning direction on one side, left or right, with respect to the traveling direction in the previous turning run, it calculates the start position Ls2 in the turning direction on the other side, left or right, with respect to the traveling direction in the current turning run, and the display unit 4 displays the display line L2 based on the start position Ls2 on the other side, left or right, of the machine body 1 on the map screen.

[0055] After the guidance information is displayed on the display unit 4 by the processing of step #24-2 or step #25-2, the passenger operates the steering wheel 16 to turn the vehicle 1. The control device 75 is configured so that the turning direction at this time can be determined by the steering angle sensor 60 as a steering operation detection means (step #24-3, step #25-3). Note that the means for determining the turning direction is not limited to the determination by the steering angle sensor 60, and may be, for example, a determination based on a set of position information of the vehicle 1 measured by the satellite positioning unit 8a, or a determination based on orientation information of the vehicle 1 measured by the inertial measurement unit 8b. In other words, the steering operation detection means may be configured to detect the steering operation by detecting the turning by, for example, the satellite positioning unit 8a or the inertial measurement unit 8b.

[0056] When the actual turning direction of the aircraft 1 is different from the guidance information displayed on the display unit 4, the guidance information displayed on the display unit 4 is changed to guidance information that matches the actual turning direction of the aircraft 1. When the right turn guidance information is displayed on the display unit 4 (step #24-2), if the actual turning direction of the aircraft 1 is a left turn (step #24-3: left turn), the start position calculation unit 76D calculates the next start position Ls2 on the left turn side (step #24-4). Then, the guidance information on the display unit 4 is changed to left turn guidance information (step #24-5). Also, when the left turn guidance information is displayed on the display unit 4 (step #25-2), if the actual turning direction of the aircraft 1 is a right turn (step #25-3: right turn), the start position calculation unit 76D calculates the next start position Ls2 on the right turn side (step #25-4). Then, the guidance information on the display unit 4 is changed to guidance information for a right turn (step #25-5). In this way, when the steering wheel 16 (steering operation tool) is operated in a turning direction opposite to the side on which the start position calculation unit 76D calculated the start position Ls2 during turning, the start position calculation unit 76D recalculates the start position Ls2 in the turning direction on the side on which the steering wheel 16 was operated, and the display unit 4 again displays the start position Ls2 on the map screen in the turning direction on the side on which the steering wheel 16 was operated relative to the vehicle 1.

[0057] Before describing steps #26 and after, a method for calculating the start position Ls2 by the start position calculation unit 76D will be described. In the embodiment shown in FIG. 8, after automatic travel control is performed along the target travel path LM[n], the vehicle position NM at the time when the end of the automatic steering control is determined based on step #22 in FIG. 7 is stored in the storage unit 81 as the terminal position Lf of the target travel path LM[n] (work travel position information WP). Before the automatic steering control on the target travel path LM[n], a left turn is performed between the terminal position Lf of the target travel path LM[n-1] and the start position Ls of the target travel path LM[n]. Therefore, a right turn is determined in step #23 in FIG. 7 before the vehicle 1 turns from the terminal position Lf of the target travel path LM[n], that is, the work travel position information WP.

[0058] In the embodiment shown in FIG. 8, the end position Lf of the target travel path LM[n-1] and the start position Ls of the target travel path LM[n] are separated by a first separation distance P1. The area of ​​the work travel based on the target travel path LM[n-1] and the area of ​​the work travel based on the target travel path LM[n] are adjacent to each other. For this reason, the first separation distance P1 is the same distance as the working width of the tilling implement 3 attached to the tractor via the PTO shaft, or is, for example, a distance smaller than the working width of the tilling implement 3 by about 10%. In FIG. 9 and FIG. 11 described later, this first separation distance P1 is as described based on FIG. 8. When the first separation distance P1 is a distance smaller than the working width of the tilling implement 3, the working width of the work travel based on the target travel path LM[n-1] and the working width of the work travel based on the target travel path LM[n] overlap by a predetermined width (for example, less than 10% of the working width).

[0059] The end position Lf of the target travel path LM[n-1] is the position where the previous turning travel started. The start position Ls of the target travel path LM[n] is the position where the previous turning travel ended. Furthermore, the end position Lf of the target travel path LM[n-1] and the start position Ls of the target travel path LM[n] are separated by a first separation distance P1. From this, the start position calculation unit 76D estimates that the next automatic steering control will be performed at a position separated by the first separation distance P1 in the lateral direction (direction perpendicular to the target orientation LA, the same below) from the target travel path LM[n]. Then, the start position calculation unit 76D calculates the start position Ls2 of the new work travel to a position separated by the first separation distance P1 from the work travel position information WP in the lateral direction opposite to the side where the target travel path LM[n-1] is located (step #25-1). The target travel route LM[n+1] shown in FIG. 8 is a target travel route LM that is scheduled to be set after the machine 1 reaches the start position Ls2.

[0060] Then, based on the processing of step #25-2, the right turn guidance information shown in 8-B of Fig. 8 is displayed as a map screen on the display unit 4. In this manner, the display unit 4 displays the surroundings of the machine body 1, including the machine body 1, as a map screen. On this map screen, the work travel position information WP and the start position Ls2 of the next work travel are displayed as linear display lines L1, L2 that are aligned with the target direction LA, respectively.

[0061] In this way, the start position calculation unit 76D calculates the start position Ls2 based on the distance between the position where the previous turning movement started and the position where the previous turning movement ended, and the display unit 4 displays the start position Ls2 calculated based on the distance in the guidance information.

[0062] The map screen of the guidance information displayed on the display unit 4 shows the machine symbol SY and the broken line turning path as shown in Fig. 8 and Fig. 9. While the machine 1 is turning, the machine symbol SY indicating the position of the machine 1 moves along the broken line turning path as shown in the guidance information of 8-B and 8-C in Fig. 9. The display unit 4 displays the turning path of the turning drive on the map screen, but in this embodiment, the turning path is not set in advance, and the broken line turning path is displayed on the map screen as a guide to reach the starting position Ls2. Based on the machine's position NM calculated by the running trajectory acquisition unit 78, the machine symbol SY is displayed as a guide at any point on the broken line turning path. In addition, the orientation of the machine symbol SY changes within the map screen in the guidance information based on the turning direction calculated by the direction deviation calculation unit 77 (see Fig. 3).

[0063] The explanation of the flowchart in FIG. 7 will be resumed. The distance calculation unit 76F (see FIG. 3) is configured to be able to calculate the separation distance between the position information stored in the storage unit 81 and the position information based on the current position of the machine body 1. While the machine body 1 is turning, the separation distance between the work travel position information WP and the machine's position NM is calculated over time by the distance calculation unit 76F (step #26). In other words, the distance calculation unit 76F calculates the separation distance using the position information when the end determination unit 76E (see FIG. 3) determines that the work travel has ended. The distance calculation unit 76F starts calculating the separation distance after the turning travel has started. Then, as shown in the guidance information 8-B and 8-C in FIG. 9, the separation distance display DF, which is the distance of the component of this separation distance that is perpendicular to the target direction LA, is displayed on the display unit 4 (step #27). In this way, when the end determination unit 76E determines that the work traveling has ended, the distance calculation unit 76F calculates the separation distance using the work traveling position information WP, which is position information based on the work traveling for which the end determination unit 76E has determined that the work traveling has ended, as position information stored in the memory unit 81. Furthermore, the display unit 4 is configured to be able to display the work traveling position information WP and the separation distance display DF. The display unit 4 starts displaying the separation distance after the turning traveling has started.

[0064] While the machine body 1 is turning, the control device 75 determines whether the machine body 1 is turning far away from the start position Ls2 of the next work run, crossing laterally based on the position information of the machine body 1 measured by the satellite positioning unit 8a (step #28). FIG. 9 shows the machine body 1 turning a distance longer than the first separation distance P1 from the work run position information WP and passing the start position Ls2 of the next work run (shown as the planned start position Ls2' in FIG. 9). The planned start position Ls2' shown in FIG. 9 was the start position Ls2 of the next work run that was initially set, but the planned start position Ls2' is not used as the start position Ls2 of the next work run. In this case, the determination of Yes is made in step #28 of FIG. 7. If the answer to step #28 is Yes, the start position calculation unit 76D calculates a new work travel start position Ls2 at a position that is a first separation distance P1 away from the planned start position Ls2' in the lateral direction opposite to the side where the work travel position information WP is located (step #29). The target travel route LM[n+2] shown in Fig. 9 is the target travel route LM that is scheduled to be set after the machine body 1 reaches the start position Ls2.

[0065] In FIG. 9, a second separation distance P2 is shown, which is the separation distance between the work travel position information WP and the start position Ls2 of the new work travel. The second separation distance P2 is twice the distance of the first separation distance P1. As a result, an unworked area of ​​a width equivalent to the working width of the tilling implement 3 is left in the horizontal direction between the work travel area based on the target travel route LM[n] and the work travel area to be performed based on the start position Ls2 of the new work travel. The width of this unworked area is a width that allows tilling work to be performed without gaps across the already worked areas on both sides when tilling work is performed. In the later-described FIGS. 10 and 11, the second separation distance P2 is the same as that described with reference to FIG.

[0066] In addition, when the start position calculation unit 76D calculates the start position Ls2 of the new work travel, the right turn guidance information shown in 8-C of FIG. 9 is displayed on the display unit 4 as a map screen based on the processing of step #30. On the map screen shown in 8-C, the work travel position information WP, the planned start position Ls2', and the start position Ls2 of the new work travel are displayed as linear display lines L1, L2', and L2 along the target direction LA. The display line L2' based on the planned start position Ls2' is located between the display line L1 based on the work travel position information WP and the display line L2 based on the start position Ls2 of the new work travel. Then, as a guide for reaching the start position Ls2 of the new work travel, a broken line turning route is displayed across the display line L1 based on the work travel position information WP and the display line L2 based on the start position Ls2 of the new work travel. The display of the aircraft symbol SY and the display of the separation distance display DF in the guidance information shown in 8-C of FIG. 9 are as described above based on the guidance information shown in 8-B of the same figure.

[0067] While the machine body 1 is turning, it is determined whether the azimuth deviation between the turning azimuth of the machine body 1 calculated by the azimuth deviation calculation unit 77 (see FIG. 3) and the target azimuth LA is within a preset allowable range (step #31). If the azimuth deviation is outside the allowable range (step #31: No), the determination process of step #28 and the processes of steps #29 and #30 in the case where the determination of step #28 is Yes are repeated. If the azimuth deviation is within the allowable range (step #31: Yes), the distance between the work travel position information WP and the start position Ls2 of the next work travel is stored in the memory unit 81 (see FIG. 3) (step #32), and the process proceeds to the process of the flowchart shown in FIG. 12 described later. In addition, the display unit 4 ends the display of the separation distance display DF after the turning travel ends.

[0068] In the judgment in step #31, it may be determined whether the lateral distance between the work travel position information WP and the vehicle's position NM calculated by the travel trajectory acquisition unit 78 is within a reference distance range based on the work width of the work travel. In this case, in addition to the work width of the work travel, an integer multiple of this work width may be used as the reference distance, or the value obtained by subtracting the amount of overlap described above from the integer multiple of this work width may be used as the reference distance.

[0069] The distance stored in the memory unit 81 in step #32 may be the actual distance between the work travel position information WP and the start position Ls2 of the next work travel, or may be a distance that is an integer multiple of a reference distance based on the work width of the work travel and is close to the actual distance. The distances stored in the memory unit 81 in this way are, for example, the first separation distance P1 and the second separation distance P2.

[0070] When turning is performed so that an unworked area of ​​a width equivalent to the working width of the tilling implement 3 is left in the lateral direction between the work travel position information WP and the start position Ls2 of the next work travel (see FIG. 9), guidance information as shown in FIG. 10 is displayed on the display unit 4 during the subsequent turning. The target travel route LM[n-1] in FIG. 10 may be considered to be the same as the target travel route LM[n+2] that is set after the machine body 1 reaches the start position Ls2 in FIG. 9.

[0071] In FIG. 10, before the automatic steering control on the target driving route LM[n], a left turn was made between the end position Lf of the target driving route LM[n-1] and the start position Ls of the target driving route LM[n]. The left turn guidance information shown in 10-A of FIG. 10 and FIG. 11 is displayed on the display unit 4 after the automatic driving control is performed along the target driving route LM[n-1]. The right turn guidance information shown in 10-B of FIG. 10 and FIG. 11 is displayed on the display unit 4 based on the processing of step #24-2 shown in FIG. 7 after the automatic driving control is performed along the target driving route LM[n] and before the vehicle 1 actually starts turning. The guidance information includes a map screen that displays the vehicle 1 and the surroundings of the vehicle 1. The guidance information is displayed on the side panel 21 shown in FIG. 2, but may be displayed on the meter panel 20 shown in the same figure.

[0072] The end position Lf of the target travel path LM[n-1] and the start position Ls of the target travel path LM[n] are separated by a second separation distance P2, and the second separation distance P2 is twice (or approximately but less than twice) the working width of the tilling implement 3. For this reason, in FIG. 10, an unworked land having a width equivalent to the working width of the tilling implement 3 is left between the work travel area based on the target travel path LM[n-1] and the work travel area based on the target travel path LM[n] in the lateral direction. When tilling work is performed on this unworked land, tilling work is performed without any gaps between the work travel area based on the target travel path LM[n-1] and the work travel area based on the target travel path LM[n].

[0073] In the embodiment shown in FIG. 10, in the previous turning run, the end position Lf of the target running path LM[n-1] and the start position Ls of the target running path LM[n] are separated by the second separation distance P2. From this, the start position calculation unit 76D estimates that the next automatic steering control will be performed at a position separated laterally by the second separation distance P2 from the target running path LM[n]. Then, the start position calculation unit 76D calculates the start position Ls2 of the next work running to a position laterally opposite to the side where the target running path LM[n-1] is located and separated by the second separation distance P2 from the work running position information WP. The target running path LM[n+1] shown in FIG. 10 is the target running path LM that is scheduled to be set after the machine body 1 reaches the start position Ls2.

[0074] The guidance information shown in FIG. 10 and FIG. 11, 10-B, shows a display line L1 based on the work travel position information WP and a display line L2 based on the start position Ls2 of the next work travel. In the embodiment shown in FIG. 10, an unworked area of ​​a width equivalent to the working width of the tilling implement 3 is left between the work travel position information WP and the start position Ls2 of the next work travel. Therefore, a display line L3 indicating this unworked area is shown between the display line L1 based on the work travel position information WP and the display line L2 based on the start position Ls2 of the next work travel. The width of this unworked area is a width that allows tilling work to be done without gaps across the already worked areas on both sides when tilling work is done.

[0075] As described above, the right turn guidance information shown in 10-B of FIG. 10 and FIG. 11 is displayed on the display unit 4 based on the processing of step #24-2 shown in FIG. 7 after automatic travel control is performed along the target travel route LM[n] and before the vehicle 1 actually starts turning. However, for example, when the target travel route LM[n] is approaching one side of the ridge of the field along the target direction LA, it is considered that the vehicle 1 cannot actually turn any further to the right from the work travel position information WP. When the vehicle 1 is actually turned to the left as shown in FIG. 11, a left turn is determined in step #24-3 of FIG. 7, and the information is changed to the left turn guidance information shown in 10-C of FIG. 11 based on the processing of step #24-5. The start position Ls2 shown in FIG. 10 is shown as the planned start position Ls2' in FIG. 11, and the planned start position Ls2' is not used as the start position Ls2 for generating the next target travel route LM.

[0076] In step #24-4 shown in FIG. 7, the start position calculation unit 76D calculates the start position Ls2 for generating the next target travel path LM based on the previous turning travel. Therefore, in principle, the start position calculation unit 76D calculates the start position Ls2 for generating the next target travel path LM to a position away from the work travel position information WP by the second separation distance P2. However, in FIG. 11, the work travel area based on the target travel path LM[n-1] has already been traveled. Therefore, when the machine body 1 turns left, if the start position Ls2 is calculated to be away from the work travel position information WP by the second separation distance P2, this area where the work travel has already been performed and the start position Ls2 of the next work travel will overlap. To avoid this inconvenience, the start position calculation unit 76D searches for the start position Ls2 by giving priority to the area of ​​the unworked land among the areas on the left turning side. In the embodiment shown in FIG. 11, as described above with reference to FIG. 10, an unworked area remains between the area of ​​work travel based on the target travel route LM[n-1] and the area of ​​work travel based on the target travel route LM[n]. The lateral width of this unworked area corresponds to the work width of the tilling implement 3. For this reason, the start position calculation unit 76D calculates the start position Ls2 for generating the next target travel route LM, instead of the planned start position Ls2' shown in FIG. 11, to a position away from the work travel position information WP by the first separation distance P1. The target travel route LM[n+2] shown in FIG. 11 is the target travel route LM that is scheduled to be set after the machine body 1 reaches the start position Ls2.

[0077] [Display of guidance information before starting automatic steering control] After the above-mentioned turning is completed, the manual steering mode of the control device 75 continues, and the straight-ahead driving by manual operation continues. During this time, the control device 75 checks the azimuth deviation of the aircraft 1 from the target azimuth LA, the direction of the front wheels 11, and the discrimination conditions of the steering state of the steering wheel 16, and judges whether or not the automatic steering mode can be switched to. Then, if the automatic steering mode can be switched to, the control device 75 starts automatic steering control by the passenger operating the trigger switch 49. At this time, the display unit 4 is configured so that the passenger can visually confirm whether or not the control device 75 can be switched to the automatic steering mode. At the same time, the display unit 4 displays guidance information to assist the passenger in steering.

[0078] While the working implement continues to travel straight ahead under manual operation, the display unit 4 displays guidance information screens shown in 13-A to 13-D in FIG. 13. The guidance information includes a map screen displaying the machine body 1 and the surroundings of the machine body 1. The guidance information is displayed on the side panel 21 shown in FIG. 2, but may also be displayed on the meter panel 20 shown in the same figure. At the right end of the guidance information screen, a steering display 82 of the steering wheel 16 and a azimuth deviation display 83 of the machine body 1 calculated by the azimuth deviation calculation unit 77 are displayed side by side vertically. In addition, a map screen including the machine body symbol SY is displayed to the left of the steering display 82 and the azimuth deviation display 83 on the screen, and a color drawing WA is displayed on the map screen in the already worked area where the tilling work has already been completed. The color drawing WA is calculated by a set of the machine position NM stored in the memory unit 81 and the working width of the tilling implement 3. This allows the already worked area and the unworked area to be visually clearly distinguished from each other. In addition, among the areas where the color drawing WA is displayed, the areas where the work runs have been performed three or more times, the areas where the work runs have been performed two times, and the areas where the work runs have been performed only once may be color-coded. In other words, the color drawing WA may be color-coded according to the number of work runs, and the already-worked areas in the guidance information may be displayed by the color drawing WA in different colors. Also, the color drawing WA may be a pointillist drawing or a pattern drawing.

[0079] The determination of the start of the automatic steering control is performed based on the flowchart shown in FIG. 12. The control device 75 is configured to use a counter Ctr for determination so that the control device 75 determines whether the automatic steering mode can be switched to. The value of the counter Ctr immediately after the end of turning is set to zero (step #40). First, it is determined whether the heading deviation of the vehicle 1 is within the range of the allowable range with respect to the target heading LA (step #41). If the heading of the vehicle 1 is tilted to the right with respect to the target heading LA (step #41: tilt to the right), the display unit 4 displays the left turn guidance information shown in 13-A of FIG. 13 (step #43-1). Then, the value of the counter Ctr is reset to zero (step #43-2). In the left turn guidance information shown in 13-A of FIG. 13, information is displayed that prompts the passenger to operate the steering wheel 16 counterclockwise. When the heading of the aircraft 1 is tilted leftward with respect to the target heading LA (step #41: tilt left), the display unit 4 displays right turn guidance information shown in 13-B of Fig. 13 (step #42-1). Then, the value of the counter Ctr is reset to zero (step #42-2). In the right turn guidance information shown in 13-B of Fig. 13, information is displayed that prompts the passenger to turn the steering wheel 16 clockwise.

[0080] If the aircraft 1 is moving straight in the direction along the target heading LA (step #41: moving straight), the counter Ctr is incremented (step #44), and the value of the counter Ctr increases. Then, it is determined whether the machine 1 has traveled a certain distance or more (step #45). Here, the "certain distance" may be a preset distance from the start position Ls2 (see Figs. 8 to 11), or may be a preset distance from a state in which the aircraft 1 travels straight in a direction along the target direction LA. If the aircraft 1 has not traveled a certain distance or more (step #45: No), the process returns to step #41.

[0081] If the vehicle 1 has traveled a certain distance or more (step #45: Yes), it is determined whether the change in the steering angle of the steering wheel 16 is maintained within an allowable range (step #46). The steering angle of the steering wheel 16 when the automatic steering control is permitted is, for example, a state in which the steering wheel 16 is not operated in the direction of right turning or left turning, and the direction of the front wheels 11 and the direction of the rear wheels 12 are parallel, but is not limited to this state. For example, if the driving area of ​​the vehicle 1 is a ground that slopes laterally, the vehicle 1 may gradually shift its position to the lower ground in the left-right direction if the vehicle 1 simply continues to move straight. In such a case, by maintaining the state in which the direction of the front wheels 11 is steered to the higher ground in the left-right direction, the vehicle 1 is likely to move forward along the target direction LA. For this reason, the steering angle of the steering wheel 16 when the automatic steering control is permitted also includes, for example, a state in which the steering wheel 16 is steered to the right or left turning direction. That is, the control device 75 is configured to permit automatic steering control when the turning angle of the steering wheel 16 continues to be maintained within a certain range. If the change in the turning angle of the steering wheel 16 is not maintained within the allowable range (step #46: No), the value of the counter Ctr is reset to zero (step #47). Note that in the process of step #47, the value of the counter Ctr may not be reset to zero, but may be decremented to decrease the value of the counter Ctr.

[0082] During the period from when it is determined in step #41 that the vehicle is traveling straight to when the determination in step #46 is being made, the display unit 4 displays guidance information as shown in 13-C of FIG. 13. Then, when the counter Ctr reaches a preset value (step #48: Yes), the display unit 4 displays guidance information as shown in 13-D of FIG. 13, and automatic steering control is permitted. Then, when the passenger operates the trigger switch 49, the control mode of the control device 75 is switched from the manual steering mode to the automatic steering mode, and automatic steering control is executed (step #49). Note that, if a sharp turn of the steering wheel 16 is detected after the determination in step #48 is Yes and before the passenger operates the trigger switch 49, the value of the counter Ctr may be reset to zero or decremented.

[0083] [Another embodiment] The present invention is not limited to the configurations exemplified in the above-described embodiments, and other representative embodiments of the present invention will be described below.

[0084] (1) In the above-described embodiment, the target orientation calculation unit 76B is configured so that the start position Ts is set by operating the trigger switch 49, and the end position Tf can be set by operating the trigger switch 49 after the vehicle 1 travels a preset distance after the start position Ts is set, but this embodiment is not limited to this. For example, the passenger may first acquire a travel trajectory by traveling the vehicle 1 for a preset distance or more, and then the passenger may set the start position Ts and the end position Tf of the acquired travel trajectory. In other words, the trigger switch 49 as one operating tool may be configured to be able to set both the start position Ts and the end position Tf of the travel trajectory acquired when calculating the target orientation LA.

[0085] (2) In the above embodiment, when it becomes possible to set the end position Tf by operating the trigger switch 49, the display unit 4 displays that it is possible to set the end position Tf, but this is not limited to the embodiment. For example, the display unit 4 may display a notice that it is possible to set the end position Tf before it becomes possible to set the end position Tf by operating the trigger switch 49. The notice may be, for example, the distance or time until it becomes possible to set the end position Tf.

[0086] (3) In the above embodiment, after the start position Ts is set by operating the trigger switch 49, if the change in steering operation is detected to exceed a preset range without the trigger switch 49 being operated, the setting of the start position Ts is canceled, but this is not limited to this embodiment. For example, when the passenger first acquires a travel trajectory by traveling the aircraft 1 for a preset distance or more, the passenger may select an area of ​​the travel trajectory excluding the turning area. In this case, the target orientation LA is calculated based on the travel trajectory excluding the turning area.

[0087] (4) In the above-described embodiment, the steering operation is performed by changing the direction of the front wheels 11, but the steering operation may be performed by changing the direction of the rear wheels 12. In short, the steering control unit 80 may be configured to be capable of controlling the steering of the traveling device along the target direction LA.

[0088] (5) As the position detection unit 8 described above, the satellite positioning unit 8a is provided in the vehicle 1 which is the target of positioning, but is not limited to a configuration in which the positioning signal of the satellite positioning system is directly received. For example, a configuration in which base stations that receive positioning signals from artificial satellites are provided at multiple locations around the work vehicle and the position information of the traveling work machine is identified by network communication processing with the multiple base stations is also possible. In short, the position detection unit 8 may be configured to be able to detect the position information of the vehicle 1 based on the positioning signal of a navigation satellite.

[0089] (6) In the above embodiment, the traveling trajectory acquisition unit 78 calculates the aircraft's position NM based on the positioning signal measured by the satellite positioning unit 8a, the orientation of the aircraft 1 calculated by the orientation deviation calculation unit 77, and the vehicle speed detected by the vehicle speed sensor 62, but is not limited to this embodiment. The traveling trajectory acquisition unit 78 may be configured to calculate the aircraft's position NM based on any one (or a combination of two) of the positioning signal, the orientation, and the vehicle speed of the aircraft 1 to acquire the traveling trajectory. In short, the traveling trajectory acquisition unit 78 may be configured to be able to acquire the traveling trajectory of the aircraft 1 based on the detection of position information over time.

[0090] (7) In the above-described embodiment, the trigger switch 49 as an operating tool is the dial switch 23. However, the trigger switch 49 may be, for example, a pump lever (not shown) that operates the tilling device 3, or a PTO clutch (not shown).

[0091] (8) Although the target travel routes LM1 to LM6 illustrated in Fig. 4 are formed in straight lines, the target travel routes LM1 to LM6 may be formed in curved lines, for example. In this case, the travel trajectory at the time of generating the reference route may be formed in a curved line, and the target orientation LA may be configured to gradually change along the curved line.

[0092] (9) In the above embodiment, the steering wheel 16 is shown as the steering operation tool. However, the steering operation tool may be, for example, a stick-type lever or a pair of buttons.

[0093] (10) Although a tractor has been given as an example of the traveling work machine according to the present invention, the present invention can also be applied to harvesters, rice transplanters, and seeding machines other than tractors.

[0094] The configurations disclosed in the above-described embodiment (including other embodiments, the same applies below) can be applied in combination with configurations disclosed in other embodiments, unless a contradiction occurs. Furthermore, the embodiments disclosed in this specification are merely examples, and the present invention is not limited to these embodiments, and can be modified as appropriate without departing from the scope of the present invention. [Industrial Applicability]

[0095] The present invention can be applied to a traveling work machine that is capable of calculating a target orientation based on a traveling trajectory and steering control of the machine body along the target orientation. [Explanation of symbols]

[0096] 1: Aircraft 4: Display section 8: Position detection section 8a: Satellite positioning unit (position detection section) 11: Front wheel (running gear) 12: Rear wheel (running gear) 15: Boarding section 16: Steering wheel (steering device) 22: Wheel support part (support member) 23: Dial switch (operating device) 49: Trigger switch (operating tool) 60: Steering angle sensor (steering operation detection means) 76B: Target direction calculation unit 78: Driving trajectory acquisition unit 80: Steering control section LA:Target direction Ts: Start position (start point) Tf: End position (end point)

Claims

1. A machine body equipped with a running gear; a position detection unit capable of detecting position information of the aircraft based on a positioning signal of a navigation satellite; a travel trajectory acquisition unit capable of acquiring a travel trajectory of the vehicle based on the time-series detection of the position information; A target orientation calculation unit that calculates a target orientation based on the travel path; a target route setting unit that generates a target travel route based on the target orientation; a steering control unit capable of controlling the steering of the traveling device along the target traveling route; An operating tool capable of setting a start point and an end point of the travel path obtained when calculating the target orientation; A display unit capable of displaying information related to the setting of the target azimuth; Equipped with the target orientation calculation unit is configured such that the start point is set by operating the operating tool, and the end point can be set by operating the operating tool after the aircraft has traveled a preset distance after the start point is set, the display unit displays information indicating that the end point cannot be set when a travel distance of the machine body after the start point is set by operating the operating tool does not reach a predetermined distance or more; The display unit displays a symbol indicating the start point and a symbol indicating the end point, and a display manner of the symbol indicating the start point and the symbol indicating the end point changes before and after the start point is set.

2. The tractor according to claim 1 , wherein the display unit displays information indicating that the start point has been set when the start point is set by operating the operating tool.

3. 3. The tractor according to claim 1, wherein when the travel distance of the vehicle after the start point is set has not reached a predetermined distance and the operating tool is operated, the display unit displays information indicating that the end point cannot be set.

4. The tractor according to any one of claims 1 to 3, wherein when it becomes possible to set the end point by operating the operating tool, the display unit displays that it is possible to set the end point.

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