Mobile work machine

Abstract

The present invention provides a mobile work machine capable of accurately setting a target movement path adjacent to the work trajectory of the mobile work machine. [Solution] The system includes a mobile machine C that travels across the field, a work device W that performs work on the field, and a control unit capable of automatic turning control to the target movement path LM2 for the next process. When transitioning from the target movement path LM to the target movement path LM2 for the next process, the control unit can perform automatic turning control. After reaching the end of the target movement path LM, the system reverses along the target movement path, and then the control unit automatically starts automatic turning control.

Description

Technical Field

[0001] The present invention relates to a traveling work machine including a traveling body that travels in a field, a working device that performs work on the field, and a route setting unit that sets a target movement route for working travel in which the traveling body travels while performing work by the working device.

Background Art

[0002] [[ID=eleven]] For example, Patent Document 1 discloses a work vehicle including a traveling body (referred to as “traveling vehicle body C” in the document), a working device that performs work on the field (referred to as “seedling planting device W” in the document), and a route setting unit (referred to as reference numeral “68” in the document) that sets a target movement route along which the traveling body should travel during working travel. The route setting unit is configured to set a teaching route corresponding to a target route to be automatically steered by teaching travel and to set a plurality of target movement routes parallel to the teaching route.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The traveling body alternately repeats working travel along the target movement route and turning travel in which it turns toward the target movement route of the subsequent process at the edge of the ridge. However, in the configuration of Patent Document 1, each target movement route is set based on the teaching route, and the travel of the traveling body along the target movement route is not considered in setting the target for the traveling body to travel in the subsequent process. Therefore, if the traveling body performs working travel in a state where it is displaced from the actual target movement route, when working travel is performed along the target movement route of the subsequent process, the already planted seedlings in the already worked area may be trampled, or an unworked area may occur between the working travel trajectories before and after turning at the edge of the ridge.

[0005] In view of the circumstances described above, the object of the present invention is to provide a mobile work machine that can accurately set a target movement path adjacent to the work travel trajectory of the mobile machine. [Means for solving the problem]

[0006] The mobile work machine of the present invention comprises a mobile body that travels in a field, a work device that performs work on the field, and a control unit capable of automatic turning control to a target travel path for subsequent processes. When transitioning from the target travel path to the target travel path for subsequent processes, the control unit can perform the automatic turning control. After reaching the end of the target travel path, the machine reverses along the target travel path, and then the control unit automatically starts the automatic turning control. Furthermore, the mobile work machine of the present invention comprises a mobile body that travels in a field, a work device that performs work on the field, and a control unit capable of automatic turning control to a target travel path for subsequent processes. When transitioning from the target travel path to the target travel path for subsequent processes, the control unit can perform the automatic turning control. After reaching the end of the target travel path, the machine reverses along the target travel path, and then the control unit starts the automatic turning control based on the operator's input. Furthermore, the mobile work machine of the present invention comprises a mobile body that travels in a field, The system includes a work device for performing work on a field, and a path setting unit for setting a target movement path for work travel in which the traveling machine moves while performing work with the work device, wherein the path setting unit sets a target for a subsequent process to be traveled by the traveling machine after it has traveled along the target movement path, based on the position acquired while the traveling machine is traveling along the target movement path, when the traveling machine alternately repeats work travel along the target movement path and turning travel toward the next target movement path.

[0007] According to the present invention, the movement of the mobile machine along the target movement path is taken into consideration when setting a target for the mobile machine to move in a subsequent process. That is, even if the mobile machine is misaligned with the actual target movement path during the work run, the target for the subsequent process is set from the position acquired during the run. As a result, the target after the turning run is set appropriately, and the work run after the turning run is performed appropriately along the work run trajectory before the turning run. As a result, a mobile work machine is realized that can accurately set a target movement path adjacent to the work run trajectory of the mobile machine.

[0008] In this configuration, The aforementioned target for the subsequent process is preferably a target movement path for the subsequent process on which the traveling machine travels.

[0009] In this configuration, the target movement path for subsequent processes is set based on the work travel trajectory of the work travel that has already been performed. This prevents the risk of trampling on already planted seedlings in the previously worked area or the creation of unworked areas between the work travel trajectory before and after turning at the edge of the ridge when the work travel is performed along the target movement path for subsequent processes. As a result, a mobile work implement is realized that can accurately set a target movement path adjacent to the work travel trajectory of the mobile implement.

[0010] In this configuration, It is preferable that the system is equipped with notification means for notifying the discrepancy between the position of the mobile body and the next target movement path when the mobile body transitions from turning to moving along the next target movement path.

[0011] Immediately after turning, the position of the vehicle is prone to deviating from the target travel path. Therefore, with this configuration, when traveling along the next target travel path, the driver is notified of the position deviation, making it easier for the driver to correct the deviation from the target travel path.

[0012] In this configuration, The notification means is preferably configured to provide notification after the completion of the turning maneuver.

[0013] During a turning maneuver, the vehicle's position is misaligned with the target travel path. If this misalignment is reported during the turning maneuver, it can easily lead the operator to mistakenly believe there is a malfunction or other problem, potentially causing inconvenience to the operator. With this configuration, the misalignment is reported only after the turning maneuver is complete, eliminating unnecessary reports and allowing the operator to receive only the necessary information.

[0014] In this configuration, Preferably, the notification means is configured to notify that the target for the subsequent process cannot be set when the target for the subsequent process cannot be set.

[0015] With this configuration, the driver is notified when it is not possible to set targets for the subsequent process, making it easier for the driver to take measures such as manual operation.

[0016] In this configuration, It is equipped with a ridge detection means that detects proximity to the ridge edge, When the ridge detection means detects proximity to the ridge, it is preferable that the path setting unit sets the target for the subsequent process.

[0017] The work run along the target movement path is completed near the edge of the field ridge. With this configuration, a target for the next process is set by detecting proximity to the edge of the ridge, so it becomes possible to set the target for the next process based on the work run trajectory along the target movement path.

[0018] In this configuration, It is preferable that the path setting unit sets the target for the subsequent process when the traveling machine transitions from traveling along the target movement path to turning.

[0019] With this configuration, the target for the next process can also be used as the target position during turning. Therefore, even if the turning is automated, for example, there is no need to set up a separate target position specifically for automated turning, and the machine can move smoothly to the target for the next process.

[0020] In this configuration, When the traveling body tilts by a preset angle or more with respect to the target movement path, it is preferable that the path setting unit sets the target for the subsequent process.

[0021] With this configuration, based on the tilt of the traveling body with respect to the target movement path, the turning travel of the traveling body can be determined, so that the target for the subsequent process can be set with a simple configuration.

[0022] In this configuration, It is preferable that the path setting unit sets the target for the subsequent process after an operation is performed on the manual operation tool.

[0023] With this configuration, since the target for the subsequent process is set by manual operation, for example, it is possible to prevent the setting of an unintended target for the subsequent process. As a result, it is possible to select either the work travel along the target movement path for the subsequent process or the work travel not along the target movement path for the subsequent process.

[0024] In this configuration, position detection means for acquiring position information based on the positioning signal of the navigation satellite is provided, it is preferable that the target for the subsequent process is set based on the average position of a plurality of the position information measured immediately before the end of the work travel.

[0025] Examples of the position detection means include DGPS (Differential GPS) and RTK-GPS (Real Time Kinematic GPS). Generally, RTK-GPS is more expensive than DGPS, but the positioning accuracy of RTK-GPS is higher than that of DGPS. Also, generally, when positioning between two points by DGPS is performed in a short time, it is known that the relative error between the two points is small. When the time during which the traveling body turns and moves to the target for the subsequent process after the end of the work travel is short, with this configuration, it is possible to accurately set the target for the subsequent process adjacent to the work travel trajectory of the traveling body without using expensive RTK-GPS.

[0026] <00…​ Preferably, the aforementioned targets for the subsequent process are configured to allow multiple targets to be set in parallel.

[0027] With this configuration, targets for subsequent processes can be set all at once, making it easier to set targets for subsequent processes, for example, when multiple mobile work machines are operating simultaneously.

[0028] In this configuration, Preferably, the target for the subsequent process is set based on the positional deviation of the traveling machine with respect to the target movement path.

[0029] This configuration allows for setting targets for subsequent processes based on the movement of the mobile machine along the target travel path.

[0030] In this configuration, Preferably, the target for the subsequent process is set at a position that is separated from the target movement path by a predetermined interval, and then shifted in parallel by an amount equal to the positional displacement of the traveling machine relative to the target movement path.

[0031] This configuration ensures that, when the machine travels along the target movement path of the subsequent process, the risk of previously planted seedlings in the previously worked area being trampled or of unworked areas being created between the work travel trajectory before and after turning at the edge of the ridge is reliably avoided.

[0032] In this configuration, Preferably, the target for the subsequent process is configured to be correctable after it has been set.

[0033] Immediately after completing a turning maneuver, the vehicle may be misaligned with the target movement path immediately following the turning maneuver. With this configuration, even if a target for a subsequent process is set, the operator can correct the misalignment of the vehicle with respect to the target movement path by changing the target for the subsequent process as needed.

[0034] In this configuration, The aforementioned target for the subsequent process is preferably set along the working trajectory of the traveling machine.

[0035] Even if the target movement path is straight, the actual working trajectory of the machine may be curved due to factors such as the machine slipping or avoiding obstacles in the field. With this configuration, even if the working trajectory is curved, the target for the subsequent process can be set so that the path based on the target for the subsequent process follows the working trajectory. This prevents the risk of trampling on already planted seedlings in the previously worked area or the creation of unworked areas between the working trajectory before and after turning at the edge of the field when the machine is working along the target movement path of the subsequent process.

[0036] In this configuration, Preferably, the route based on the aforementioned target for the subsequent process is configured to have a more linear shape than the aforementioned work travel trajectory.

[0037] If the working trajectory of the mobile machine meanders in a complex way relative to the target movement path, and the subsequent process target is set along the working trajectory of the mobile machine, the path based on the subsequent process target will also meander in a complex way, and there is a risk that the mobile machine will not be able to move along that path accurately. With this configuration, the path based on the subsequent process target is set to be a straight line, so that the mobile machine can work smoothly along the target movement path.

[0038] In this configuration, A control means is provided that outputs a control signal so that the aforementioned work drive is performed. The aforementioned target movement path is substantially straight, Preferably, the route setting unit is configured to set the target for the subsequent process as a function independent of the control means.

[0039] This configuration allows for automatic operation along a roughly linear target movement path. Furthermore, since the control means and the path setting unit are independent functions, it is possible to wait for the operator's decision on whether to operate the machine along a path based on a subsequent target after the machine has completed operation along the target movement path.

[0040] In this configuration, A control means is provided that outputs a control signal so that the aforementioned work drive is performed. The aforementioned target movement path is substantially straight, Preferably, the route setting unit is configured to set the target for the subsequent process as a function linked to the control means.

[0041] In this configuration, after the mobile machine performs work along the target movement path, a target for the next process is set, and the machine automatically performs work along the path based on the next process target. This enables automatic work along the path based on the next process target, in conjunction with the setting of the next process target.

[0042] In this configuration, Preferably, if the traveling machine deviates significantly from the target travel path by a distance greater than a preset distance, the target travel path is configured not to be used for the work travel.

[0043] If the vehicle deviates significantly from the target travel path, it is highly likely that the operator is intentionally manipulating the vehicle. With this configuration, the target travel path can be avoided for work travel, making it easy to prioritize the operator's manual actions even without specialized control tools.

[0044] In this configuration, A reference path is set based on the work run immediately before the aforementioned turning run. In other fields, it is preferable that the route setting unit is configured to set the target for the subsequent process based on the reference route.

[0045] With this configuration, the reference path can be used to set targets for subsequent processes in other fields, making it easy to set target movement paths without having to perform teaching runs in other fields.

[0046] In this configuration, It is preferable that the system is equipped with a memory unit capable of storing multiple reference routes for each field.

[0047] With this configuration, the target movement path can be set simply by reading the corresponding reference path for each field from the memory unit, eliminating the need to repeatedly perform teaching runs. [Brief explanation of the drawing]

[0048] [Figure 1] This is an overall side view of the rice transplanter. [Figure 2] This is an overall plan view of the rice transplanter. [Figure 3] This is a front view of a rice transplanter. [Figure 4] This is a diagram showing the steering and steering unit. [Figure 5] This is a control configuration cylinder. [Figure 6] This is a plan view diagram illustrating the operation of the automatic steering control system across the entire rice paddy field. [Figure 7] This is an explanatory diagram illustrating automatic steering control using an inertial measurement unit. [Figure 8] This is an explanatory diagram showing the setting of target movement paths for subsequent processes. [Figure 9] This is an explanatory diagram illustrating automatic turning control at the edge of a field. [Figure 10] This is an explanatory diagram illustrating automatic turning control at the edge of a field. [Figure 11] This is an explanatory diagram illustrating automatic turning control at the edge of a field. [Figure 12] This is an explanatory diagram illustrating the correction of positional deviations in automatic steering control. [Figure 13] This is an explanatory diagram showing the display unit. [Figure 14] This is an explanatory diagram showing another embodiment of setting the target movement path for the subsequent process. [Figure 15] This is an explanatory diagram showing another embodiment of setting the target movement path for the subsequent process. [Figure 16] This is an explanatory diagram showing another embodiment of setting the target movement path for the subsequent process. [Modes for carrying out the invention]

[0049] [Basic configuration of a mobile work machine] Embodiments of the present invention will be described based on the drawings. Here, a riding-type rice transplanter will be used as an example of a mobile implement of the present invention. As shown in Figure 2, in this embodiment, arrow F is the front side of the mobile implement C, arrow B is the rear side of the mobile implement C, arrow L is the left side of the mobile implement C, and arrow R is the right side of the mobile implement C.

[0050] As shown in Figures 1 to 3, the riding-type rice transplanter is equipped with a traveling body C having a pair of left and right steering wheels 10 and a pair of left and right rear wheels 11, and a seedling planting device W as a working device capable of planting seedlings in the field. The pair of left and right steering wheels 10 are located on the front side of the traveling body C and are configured to allow the direction of the traveling body C to be changed, while the pair of left and right rear wheels 11 are located on the rear side of the traveling body C. The seedling planting device W is connected to the rear end of the traveling body C so as to be able to move up and down by the extension and retraction of a lifting hydraulic cylinder 20.

[0051] The front of the mobile unit C is equipped with an openable bonnet 12. At the tip of the bonnet 12 is a rod-shaped center mascot 14, which serves as a guide for traveling along an indicator line (not shown) drawn on the field by a marker device 33. The mobile unit C is equipped with a body frame 15 that extends in the front-to-back direction, and a support column frame 16 is erected at the front of the body frame 15.

[0052] An engine 13 is housed inside the bonnet 12. Although not described in detail, the power from the engine 13 is transmitted to the steering wheels 10 and rear wheels 11 via an HST (hydrostatic continuously variable transmission) (not shown) installed on the aircraft, and the power after gear changes is transmitted to the seedling planting device W via an electric motor-driven planting clutch (not shown).

[0053] As shown in Figures 1 and 2, the seedling planting device W is equipped with four transmission cases 22, eight rotating cases 23, a leveling float 25, a seedling tray 26, and a marker device 33. The rotating cases 23 are rotatably supported on the left and right rear sides of each transmission case 22. A pair of rotary planting arms 24 are provided at both ends of each rotating case 23. The leveling floats 25 are used to level the surface of the field, and multiple floats are provided on the seedling planting device W. Mat-shaped seedlings for planting are placed on the seedling tray 26. The marker device 33 is provided on the left and right sides of the seedling planting device W and forms indicator lines (not shown) on the surface of the field.

[0054] The seedling planting device W rotates each rotating case 23 using power transmitted from the transmission case 22 while driving the seedling tray 26 to move back and forth horizontally. The planting arms 24 alternately take out seedlings from the bottom of the seedling tray 26 and plant them on the field surface. The seedling planting device W is configured as an eight-row planting type, with planting arms 24 provided on eight rotating cases 23 to plant seedlings. However, the seedling planting device W may also be a four-row planting type, a six-row planting type, a seven-row planting type, or a ten-row planting type.

[0055] Although not described in detail, the marker device 33 is configured to be switchable between an operational position and a retracted position. In the operational position, the marker device 33 makes contact with the field surface as the traveling machine C moves, forming an indicator line (not shown) on the field surface corresponding to the next work step. In the retracted position, the marker device 33 moves upward away from the field surface. The position switching of the marker device 33 is performed by an electric motor (not shown).

[0056] As shown in Figures 1 to 3, the left and right sides of the bonnet 12 of the mobile unit C are equipped with a plurality (for example, four) of normal spare seedling trays 28 and spare seedling trays 29. The normal spare seedling trays 28 are configured to hold spare seedlings for supplying the seedling planting device W. The spare seedling trays 29 are configured as rails on which spare seedlings for supplying the seedling planting device W can be placed. The left and right sides of the bonnet 12 of the mobile unit C are equipped with a pair of left and right spare seedling frames 30, which are tall frame members that support each of the normal spare seedling trays 28 and spare seedling trays 29, and the upper parts of the left and right spare seedling frames 30 are connected by a connecting frame 31.

[0057] As shown in Figures 1 to 3, the central part of the mobile body C is equipped with a control unit 40 where various driving operations are performed. The control unit 40 is equipped with a driver's seat 41, a steering wheel 43, a main gear lever 44, and an operating lever 45. The driver's seat 41 is located in the central part of the mobile body C and is configured so that a driver can sit in it. The steering wheel 43 is configured to allow manual steering of the steering wheels 10. The main gear lever 44 is configured to allow switching between forward and reverse movement and changing the driving speed. The raising and lowering of the seedling planting device W and the switching of the left and right marker devices 33 are performed by the operating lever 45. The steering wheel 43, main gear lever 44, operating lever 45, etc. are located on top of the control tower 42, which is located on the front side of the mobile body of the driver's seat 41. A boarding step 46 is provided at the foot area of ​​the control unit 40. Boarding step 46 also extends to both the left and right sides of the bonnet 12.

[0058] When the main transmission lever 44 is operated, the angle of the swash plate in the HST (not shown) is changed, and the power of the engine 13 is continuously variable. Although not shown, the swash plate angle of the HST is controlled by a hydraulic unit equipped with a servo-hydraulic control device. Known hydraulic pumps and hydraulic motors are used for the servo-hydraulic control device.

[0059] When the operating lever 45 is moved to the raised position, the planting clutch (not shown) is disengaged, interrupting the power transmission to the seedling planting device W. This activates the lifting hydraulic cylinder 20, causing the seedling planting device W to rise and the left and right marker devices 33 (see Figure 1) to be moved to the retracted position. When the operating lever 45 is moved to the lowered position, the seedling planting device W lowers and comes to rest on the field surface. In this lowered state, when the operating lever 45 is moved to the right marker position, the right marker device 33 moves from the retracted position to the operating position. When the operating lever 45 is moved to the left marker position, the left marker device 33 moves from the retracted position to the operating position.

[0060] When the operator starts rice planting, they operate the control lever 45 to lower the seedling planting device W and start the power transmission to the seedling planting device W to begin the rice planting operation. When stopping the rice planting operation, they operate the control lever 45 to raise the seedling planting device W and disconnect the power transmission to the seedling planting device W.

[0061] The control panel 47 at the top of the control tower 42 of the driver's unit 40 is equipped with a display unit 48 capable of displaying various information using a liquid crystal display. The display unit 48 may be a touch-panel type liquid crystal display. A push-operated start / end point setting switch 49A is provided to the right of the display unit 48, and a push-operated target setting switch 49B (operating device) is provided to the left of the display unit 48. Alternatively, the start / end point setting switch 49A may be provided to the left of the display unit 48, and the target setting switch 49B may be provided to the right of the display unit 48. The functions of the start / end point setting switch 49A and the target setting switch 49B will be described later.

[0062] The grip portion of the main gear shift lever 44 is equipped with a push-operated automatic steering switch 50. The automatic steering switch 50 is of the automatic return type and commands the switching of automatic steering control on and off each time it is pressed. The automatic steering switch 50 is positioned so that it can be pressed, for example, with the thumb while the grip portion of the main gear shift lever 44 is held in the hand.

[0063] As shown in Figure 4, the vehicle body C is equipped with a steering unit U as a steering operation means capable of steering the left and right steering wheels 10. The steering unit U includes a steering shaft 54, a pitman arm 55, left and right connecting mechanisms 56 that are linked to the pitman arm 55, a steering motor 58, and a gear mechanism 57. The steering shaft 54 ​​is linked to the steering handle 43 via a clutch 53. The pitman arm 55 is configured to swing in conjunction with the rotation of the steering shaft 54. The gear mechanism 57 is configured to link the steering motor 58 to the steering shaft 54.

[0064] The steering shaft 54 ​​is linked to the left and right steering wheels 10 via the pitman arm 55 and the left and right connecting mechanisms 56. A steering angle sensor 60, consisting of a rotary encoder, is provided at the lower end of the steering shaft 54, and the amount of rotation of the steering shaft 54 ​​is detected by the steering angle sensor 60. A torque sensor 61 is provided in the middle of the steering shaft 54 ​​to detect the torque applied to the steering wheel 43.

[0065] For example, when the steering motor 58 is rotating the steering shaft 54 ​​in a predetermined direction, if the steering handle 43 is manually operated in the opposite direction to that rotation, the torque sensor 61 can detect this. Also, when the steering motor 58 is stopped, if the steering handle 43 is manually operated in any direction, the torque sensor 61 can detect this. When such manual operation occurs, the steering motor 58 can be activated based on the manual operation, taking precedence over automatic steering control.

[0066] The clutch 53 is provided between the steering shaft 54 ​​and the steering handle 43, and when the clutch 53 is disengaged, power is no longer transmitted between the steering handle 43 and the steering shaft 54. The clutch 53 is configured to be disengaged, for example, when automatically turning at the edge of a field, so that during automatic turning, the rotation of the steering shaft 54 ​​caused by the operation of the steering motor 58 is no longer transmitted to the steering handle 43.

[0067] When the steering unit U performs automatic steering, the steering motor 58 is driven, and the driving force of the steering motor 58 rotates the steering shaft 54, thereby changing the steering angle of the steering wheels 10. When automatic steering is not performed, the steering unit U can be rotated manually by operating the steering handle 43.

[0068] [Configuration of automatic steering control] Next, we will describe the configuration for performing automatic steering control. The mobile vehicle C is equipped with a satellite positioning unit 70 (position detection means) that determines the vehicle's position using GPS (Global Positioning System), a well-known technology, as an example of a satellite positioning system (GNSS: Global Navigation Satellite System) that receives radio waves from satellites to detect the vehicle's position. In this embodiment, the satellite positioning unit 70 uses DGPS (Differential GPS: relative positioning method), but it is also possible to use RTK-GPS (Real Time Kinematic GPS: interferometric positioning method).

[0069] Specifically, as a means of position detection, a satellite positioning unit 70 is installed on the object to be positioned (mobile vehicle C). The satellite positioning unit 70 has a receiving device 72 with an antenna 71 that receives radio waves transmitted from multiple GPS satellites orbiting the Earth. Based on the radio wave information (positioning signals) received from navigation satellites, the position of the receiving device 72, i.e., the satellite positioning unit 70, is determined.

[0070] As shown in Figures 1 to 3, the satellite positioning unit 70 is located at the front of the mobile vehicle C and is attached to the connecting frame 31 via a plate-shaped support plate 73. As shown in Figures 1 and 3, the receiving device 72 is supported at a high position by the connecting frame 31 and the auxiliary seedling frame 30. This reduces the risk of reception interference to the receiving device 72 and improves the radio wave reception sensitivity of the receiving device 72.

[0071] Furthermore, the receiving device 72 is not limited to being attached to a connecting frame 31 provided on the upper part of the spare seedling frame 30. For example, a separate frame may be provided that has the function of moving the receiving device 72 to a position lower than the upper part of the spare seedling frame 30, separate from the spare seedling frame 30. In addition, the separate frame may be configured to extend to the rear side of the machine.

[0072] In addition to the satellite positioning unit 70, the vehicle C is equipped with an inertial measurement unit 74, which has, for example, an IMU (Inertial Measurement Unit) 74A, as a means for detecting the orientation of the vehicle C. The inertial measurement unit 74 may also have a gyro sensor or an acceleration sensor instead of the IMU 74A. Although not shown in the figures, the inertial measurement unit 74 is located, for example, below and behind the driver's seat 41, at a low position in the center of the vehicle C in the lateral direction. The inertial measurement unit 74 can detect the angular velocity of the turning angle of the vehicle C, and the orientation change angle ΔNA of the vehicle (see Figure 7) can be determined by integrating the angular velocity. Therefore, the measurement information measured by the inertial measurement unit 74 includes orientation information of the vehicle C. Although not described in detail, the inertial measurement unit 74 can also measure the angular velocity of the left-right tilt angle and the front-rear tilt angle of the vehicle C, in addition to the angular velocity of the turning angle of the vehicle C.

[0073] As shown in Figure 5, the vehicle body C is equipped with a control device 75. The control device 75 is configured to be switchable 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.

[0074] The control device 75 includes a route setting unit 76 (route setting means), an azimuth deviation calculation unit 77, a control unit 78 (control unit), and a steering control unit 79 (control unit). The route setting unit 76 sets the target movement path LM (see Figure 6) that the mobile vehicle C should travel. Details of the azimuth deviation calculation unit 77 will be described later. The control unit 78 calculates and outputs an operation amount so that the mobile vehicle C travels along the target movement path LM, based on the position information of the mobile vehicle C measured by the satellite positioning unit 70 and the azimuth information of the mobile vehicle C measured by the inertial measurement unit 74. The steering control unit 79 controls the steering motor 58 based on the operation amount. Specifically, the control device 75 is equipped with a microcomputer, and the route setting unit 76, the azimuth deviation calculation unit 77, the control unit 78, and the steering control unit 79 are configured by a control program.

[0075] A start / end point setting switch 49A is provided for setting the target movement path LM used for automatic steering control through a teaching process. The start position Ts and the end position Tf are set by operating the start / end point setting switch 49A. Note that the start / end point setting switch 49A does not have to consist of a single switch; it may be configured with a switch for setting the start position Ts and a switch for setting the end position Tf, each located side by side. As mentioned above, the start / end point setting switch 49A is located on the right side of the display unit 48, but is not limited to this, and may be located on the left side of the display unit 48.

[0076] The control device 75 receives information from the satellite positioning unit 70, the inertial measurement unit 74, the automatic steering switch 50, the start / end point setting switch 49A, the target setting switch 49B, the steering angle sensor 60, the torque sensor 61, the vehicle speed sensor 62, the obstacle detection unit 63 (edge ​​detection means), and other sources. The vehicle speed sensor 62 is configured to detect vehicle speed by, for example, the rotational speed of the transmission shaft in the transmission mechanism relative to the rear wheels 11. The vehicle speed may also be determined by considering positioning data from the satellite positioning unit 70, in addition to the vehicle speed sensor 62. The obstacle detection unit 63 is provided on the front and both sides of the vehicle body C and is configured to detect obstacles such as field edges and transmission towers within the field, for example, by using an optical distance sensor or an image sensor. When an obstacle is detected by the obstacle detection unit 63, the driver is alerted by, for example, a buzzer or voice guidance from the alarm unit 64. The control device 75 is connected to an alert unit 59 (alert means), which is configured to alert the driver of status such as vehicle speed and engine speed. The alert unit 59 may be configured to display information on the display unit 48, or it may be configured to change the flashing pattern of the LED lighting on the center mascot 14. Furthermore, the alarm unit 64 may be configured to display alarms on the display unit 48 via the notification unit 59. In this case, for example, an alarm for edge detection will be displayed on the display unit 48. Alternatively, the alarm unit 64 may be configured as part of the notification unit 59.

[0077] Based on the operation of the start / end point setting switch 49A, a teaching route corresponding to the target route to be automatically steered is set by the route setting unit 76 through a teaching process.

[0078] The azimuth deviation calculation unit 77 calculates the angular deviation, i.e., the azimuth deviation, between the detected direction of the mobile vehicle C (self-direction NA) detected by the inertial measurement unit 74 and the target direction LA in the target movement path LM. When the control device 75 is set to automatic steering mode, the control unit 78 calculates and outputs an operation amount for controlling the steering motor 58 so that the angular deviation is minimized.

[0079] During automatic steering control of the mobile vehicle C, the steering control unit 79 performs automatic steering control based on the control input output by the control unit 78. Specifically, the steering motor 58 is operated so that the detected position of the mobile vehicle C (self-position NM), detected by the satellite positioning unit 70 and the inertial measurement unit 74, becomes a position on the target movement path LM.

[0080] In this embodiment, the control signal may be an input variable output by the control unit 78, or it may be a voltage value or current value used by the steering control unit 79 to operate the steering motor 58.

[0081] [Target travel route] In a paddy field, the rice transplanter alternates between working along a straight row planting path and performing a turn-around near the edge of the ridge to move to the next row planting path. Figure 6 shows multiple target movement paths LM arranged in parallel along the teaching path. In this embodiment, each target movement path LM(1) to LM(6) is set by the path setting unit 76 in the following procedure.

[0082] First, the operator positions the mobile unit C at the starting point Ts at the edge of the field ridge and operates the start / end point setting switch 49A. At this time, the control device 75 is set to manual steering mode. Then, while manually steering, the operator moves the mobile unit C from the starting point Ts along the straight shape of the edge of the field ridge on the side, to the end point Tf near the edge of the field ridge on the opposite side, and then operates the start / end point setting switch 49A again. This executes the teaching process. In other words, a teaching path is set connecting the starting point Ts and the end point Tf based on the position coordinates based on the position data acquired by the satellite positioning unit 70 at the starting point Ts and the position coordinates based on the position data acquired by the satellite positioning unit 70 at the end point Tf. The direction along this teaching path is set as the reference target bearing LA. Furthermore, the position coordinates at the endpoint Tf may be calculated not only based on positioning data from the satellite positioning unit 70, but also based on the distance from the starting point Ts based on the vehicle speed sensor 62 and the azimuth information of the mobile vehicle C based on the inertial measurement unit 74. In addition, the movement of the mobile vehicle C between the starting point Ts and the endpoint Tf may be work-related movement involving rice planting, or non-work-related movement.

[0083] After the teaching path has been set, the machine performs a turn along the edge of the ridge to move to a planting path adjacent to the teaching path. In this embodiment, the machine moves to the starting position Ls(1). The turn along the edge of the ridge may be performed by the operator manually operating the steering handle 43, or it may be performed by automatic turning control as described later. At this time, the control unit 78 can determine that the machine has turned by reversing its own heading NA. The reversal of the own heading NA can be detected by the satellite positioning unit 70 and the inertial measurement unit 74.

[0084] The turning of the mobile unit C may be determined not only by reversing its own heading NA, but also by the operation of various devices. Examples of the operation of various devices include the raising of the seedling planting device W, the leveling rotor (not shown), the leveling float 25, etc., the disengagement of the side clutch (not shown), or the interruption of the power transmission to the seedling planting device W. Furthermore, the arrival of the mobile unit C at its starting position Ls(1) may be determined by the satellite positioning unit 70.

[0085] After the teaching route has been set, the target movement route LM(1) is set by the route setting unit 76 at any time. The target movement route LM(1) may be set when the teaching route has been set, while the mobile unit C is turning, or after the mobile unit C has turned. At the timings described above, the target movement route LM(1) is set by the operator operating the target setting switch 49B. However, the system is not limited to the target setting switch 49B; for example, the target movement route LM(1) may be set by the operator operating the automatic steering switch 50 or the like. Furthermore, the target movement route LM(1) may be set automatically without any operator intervention.

[0086] After it is determined that the turning of the mobile vehicle C is complete, the manual steering mode of the control device 75 continues, and straight-line driving by human operation continues. During this time, the control device 75 checks the determination conditions such as the azimuth deviation of the vehicle's heading NA calculated by the azimuth deviation calculation unit 77, the direction of the steering wheels 10, and the steering angle of the steering handle 43, and determines whether it is possible to switch to automatic steering mode. If it is possible to switch to automatic steering mode, the control device 75 permits operation of the automatic steering switch 50. At this time, whether the control device 75 is in a state where it can switch to automatic steering mode is notified by the notification unit 59.

[0087] If the control device 75 is unable to switch to automatic steering mode, the notification unit 59 is configured to also notify the reason for this. This allows the driver to be notified of unfavorable conditions for automatic steering control, making it easier for the driver to prepare the conditions for starting automatic steering control. The notification by the notification unit 59 may be an audible sound such as a buzzer, or it may be the illumination or flashing of an LED light on the center mascot 14, or it may be displayed on the display unit 48. Furthermore, the notification by the notification unit 59 may be configured to be a temporary notification or a continuous notification.

[0088] Examples of adverse conditions for automatic steering control include a significantly large deviation in the aircraft's heading NA from the target heading LA, a large lateral displacement of the steering wheels 10, and the vehicle speed of the aircraft C being too fast or too slow. Another example of an adverse condition for automatic steering control is when the number of navigation satellites that the satellite positioning unit 70 can acquire is less than the number set in advance.

[0089] When the operator operates the automatic steering switch 50 while operation of the automatic steering switch 50 is permitted, the route setting unit 76 sets the target movement path LM(1), and the control device 75 switches from manual steering mode to automatic steering mode. Then, automatic steering control along the target movement path LM(1) is started. The target movement path LM(1) is set adjacent to the teaching path and along the direction of the target direction LA, and is the target movement path LM on which the mobile machine C performs its first work run after the teaching process. In addition, the operator operates the control lever 45 to lower the seedling planting device W after the mobile machine C has turned and perform the rice planting work, but it is also possible that the configuration is such that when the control device 75 switches from manual steering mode to automatic steering mode, the seedling planting device W lowers and the rice planting work begins.

[0090] Automatic steering control continues until the obstacle detection unit 63 detects the edge of a ridge near the end point Lf(1) on the opposite side of the starting point Ls(1) of the target movement path LM(1). During this time, for example, when automatic steering control is in operation, the swashplate of the HST is operated by an electric motor, and even if the driver operates the main shift lever 44, the operation of the main shift lever 44 is not transmitted to the HST (not shown). Alternatively, the main shift lever 44 may be constrained to a predetermined position so as not to move during automatic steering control. This configuration is particularly useful in configurations where the main shift lever 44 and the HST are mechanically linked. Furthermore, even if the main shift lever 44 cannot operate the HST during automatic steering control, the engine 13 may stop or the traveling machine C may stop through a dedicated operating tool (not shown) or brake operation, making it possible for the main shift lever 44 to operate the HST.

[0091] When the obstacle detection unit 63 determines that the distance between the vehicle C and the edge of the field is within a preset range, the driver is notified by an alarm from the alarm unit 64. At this time, the alarm from the alarm unit 64 may be an audible sound such as a buzzer, or it may be the illumination or flashing of an LED light on the center mascot 14, or it may be displayed on the display unit 48. Then, when the obstacle detection unit 63 continues to detect the edge of the field for a preset period of time, the detection of the edge of the field is determined, the engine 13 stops, and the control device 75 switches to manual steering mode, canceling automatic steering control. Alternatively, when the detection of the edge of the field is determined, the engine 13 may not stop, but the vehicle C may decelerate or stop. In other words, when the distance between the vehicle C and the edge of the field is determined to be within a preset range, it is sufficient for the automatic steering control to be canceled.

[0092] Thus, the system is configured to deactivate the automatic steering control near the edge of a field once the detection of the edge of a field is determined. However, the system may also be configured to continue the automatic steering control even near the edge of a field if certain conditions are met. For example, even if the obstacle detection unit 63 detects the edge of a field and the driver is notified of an alarm, the system may be configured to continue the automatic steering control without determining the detection of the edge of a field if the driver continues to operate the automatic steering switch 50. In this case, the system may be configured to deactivate the automatic steering control when the driver stops operating the automatic steering switch 50. This allows the automatic steering control to continue regardless of the detection of the edge of a field until the vehicle C reaches the final position Lf(1). Furthermore, the continuation of the automatic steering control as described above is not limited to operation of the automatic steering switch 50, but may also be achieved by operation of, for example, the start / end point setting switch 49A or the target setting switch 49B.

[0093] When the mobile machine C reaches the endpoint Lf(1) of the target movement path LM(1), the operator operates the steering handle 43 towards the unworked area of ​​the target movement path LM(1) to perform a turn along the edge of the field, and the mobile machine C moves to the starting position Ls(2) of the next work run. Note that this turn along the edge of the field may be performed by automatic turning control, which will be described later. Before the mobile machine C turns, the operator can operate the control lever 45 to raise the seedling planting device W, but it is also possible that the operation of the steering handle 43 will interrupt the power transmission to the seedling planting device W, causing the seedling planting device W to rise. Then, it is determined that the mobile machine C has turned.

[0094] After the work run along the target movement path LM(1) is completed, the target movement path LM(2) is set by the path setting unit 76 at any time. The target movement path LM(2) may be set when the obstacle detection unit 63 determines the edge of a ridge, while the mobile machine C is turning, or after the mobile machine C has turned. At the timings described above, the target movement path LM(2) is set by the operator operating the target setting switch 49B. However, the system is not limited to the target setting switch 49B; for example, the operator may operate the automatic steering switch 50 or the like to set the target movement path LM(2). Furthermore, the system may be configured so that the target movement path LM(2) is set automatically without any operator intervention. After the target movement path LM(2) is set adjacent to the unworked area side of the target movement path LM(1), automatic steering control is started along the target movement path LM(2), and the mobile machine C performs the work run.

[0095] After the mobile machine C reaches the endpoint Lf(2) of the target movement path LM(2), the process of setting the target movement path LM after turning along the edge of the field and then performing the work run is repeated for target movement paths LM(3), LM(4), LM(5), and LM(6) in that order. In other words, each target movement path LM is set one at a time.

[0096] During automatic steering control, the satellite positioning unit 70 acquires information on the vehicle's position NM over time. In addition, the vehicle speed is calculated by the vehicle speed sensor 62, and the relative azimuth change angle ΔNA is measured over time by the inertial measurement unit 74, as shown in Figure 7. The azimuth deviation calculation unit 77 calculates the vehicle's azimuth NA from the point where automatic steering control started over time by integrating the azimuth change angle ΔNA. The azimuth deviation calculation unit 77 then calculates the azimuth deviation between the vehicle's azimuth NA and the target azimuth LA. The control unit 78 outputs an input variable so that the vehicle's azimuth NA matches the target azimuth LA, and the steering control unit 79 operates the steering motor 58 based on the input variable. As a result, the vehicle C travels accurately along the target travel path LM. The driver does not operate the steering wheel 43.

[0097] [Setting the target travel route] Figure 8 shows the next-process target movement path LM2, which is adjacent to the target movement path LM. The next-process target movement path LM2 is set as the target movement path that the traveling machine C will perform work on after the target movement path LM. Therefore, if the target movement path LM in Figure 8 corresponds to the target movement path LM(1) in Figure 6, then the next-process target movement path LM2 in Figure 8 corresponds to the target movement path LM(2) in Figure 6. Also, if the target movement path LM in Figure 8 corresponds to the target movement path LM(2) in Figure 6, then the next-process target movement path LM2 in Figure 8 corresponds to the target movement path LM(3) in Figure 6. The same applies to the target movement path LM and the next-process target movement path LM2 in Figures 9 to 11, which will be described later.

[0098] Note that the target movement path LM in Figure 8 may be the teaching path described above. In this case, the target movement path LM2 for the downstream process in Figure 8 corresponds to the target movement path LM(1) in Figure 6.

[0099] Basically, the target movement path LM2 for the subsequent process is set based on the positioning data of the satellite positioning unit 70, and is set at a predetermined distance P from the target movement path LM. Here, the predetermined distance P is the distance corresponding to the working width in which the seedling planting device W performs the rice planting work.

[0100] However, DGPS errors can generally range from a few meters. Therefore, when DGPS is used as the satellite positioning unit 70, the coordinate position NM of the vehicle based on the positioning data actually acquired by the satellite positioning unit 70 may be misaligned with the actual target movement path LM. Consequently, if the target movement path LM2 for subsequent processes is set based solely on the coordinate position NM of the vehicle actually acquired by the satellite positioning unit 70, there is a risk that already planted seedlings in the work area may be trampled, or that unworked areas may occur between the work trajectory before and after turning at the edge of the ridge.

[0101] In this embodiment, the distance between the target movement path LM2 for the subsequent process and the target movement path LM is calculated based on the actual positional deviation of the mobile machine C, which has undergone automatic steering control along the target movement path LM. As mentioned above, DGPS errors can range from several meters, but it is known that when positioning between two points by DGPS is performed in a short period of time, such as ten seconds, the error in the relative position between the two points is extremely small. Taking advantage of this characteristic, the path setting unit 76 is configured to set the target movement path LM2 for the subsequent process at a position separated from the machine's position NM by a relative distance, based on positioning data measured immediately before turning at the edge of the field. In other words, the target movement path LM2 for the subsequent process is set at a position separated by a set distance P from the machine's position NM, which is calculated based on positioning data from the satellite positioning unit 70.

[0102] In automatic steering control along the target movement path LM, if the mobile unit C performs work while being misaligned by a position deviation d toward the unworked area relative to the target movement path LM, the actual work trajectory of the mobile unit C will be the dashed-dotted line La shown in Figure 8. The dashed-dotted line La trajectory is calculated based on positioning data from the satellite positioning unit 70. The absolute error in the positioning data measured by the satellite positioning unit 70 is also included in the position deviation d.

[0103] Immediately before the vehicle turns along the edge of the field, the position coordinates NM3 of the vehicle's position NM are determined as positioning data by the satellite positioning unit 70. After the position coordinates NM3 are determined, and before automatic driving control begins, the vehicle turns along the edge of the field, and at any arbitrary timing, the target movement path LM2 for the subsequent process is set. Since normal vehicle turns along the edge of the field are completed in a few seconds, the relative error between the position coordinates determined by the satellite positioning unit 70 immediately after the completion of the vehicle turns along the edge of the field and the position coordinates NM3 immediately before the vehicle turns along the edge of the field is small. Note that the position coordinates NM3 may be the average of multiple positioning data determined by the satellite positioning unit 70 near the endpoint position Lf (the average position of multiple position information).

[0104] Normally, the target movement path LM2 for the subsequent process is set at a position separated by a set distance P from the target movement path LM, i.e., at the position indicated by the dashed line lm in Figure 8. In contrast, in this embodiment, the target movement path LM2 for the subsequent process is set to be shifted parallel to the unworked area by a position deviation d from the dashed line lm, corresponding to the position deviation d of the traveling machine C.

[0105] Furthermore, it is conceivable that the actual working trajectory of the mobile machine C may be shifted by a positional deviation d toward the already working area relative to the target movement path LM. In this case, the target movement path LM2 for the subsequent process is set by shifting it parallel to the target movement path LM by a positional deviation d toward the already working area from the set distance P.

[0106] This allows the target to be set at a distance P from the current position NM, even if the positioning data measured by the satellite positioning unit 70 contains errors. By setting the target movement path LM2 for the subsequent process at a distance equal to the working width of the seedling planting device W, the risk of trampling on already planted seedlings in the already worked area or the occurrence of unworked areas between the work travel trajectory before and after turning at the edge of the ridge is prevented. This configuration is particularly useful when DGPS is used as the satellite positioning unit 70.

[0107] [Regarding automatic turning at the edge of the field] Basically, turning at the edge of a field is performed by the operator operating the steering handle 43. However, turning at the edge of a field by manual operation requires changing the direction of the machine so that it reaches the starting position Ls of the next target movement path LM and the forward direction of the machine matches the target bearing of the target movement path LM. For this reason, there are many factors that depend on the operator's skill level, which can be burdensome for inexperienced operators. In particular, in the configuration described above, where the target movement path LM2 for the next process is set based on the position coordinates NM3 measured immediately before turning at the edge of a field, it is desirable that the traveling machine C reaches the starting position Ls of the next work run within a certain period of time and prepares the conditions for starting automatic steering control within that certain period of time. For this reason, in this embodiment, the control unit 78 is configured to be switchable to automatic turning control.

[0108] In automatic turning control, the control unit 78 is configured to instruct the steering control unit 79 to perform a steering operation based on the vehicle's position NM, which is determined by the satellite positioning unit 70, for example, through data conversion in a lookup table. Furthermore, the system is not limited to the satellite positioning unit 70; for example, the vehicle's position NM may be calculated by integrating the vehicle speed measured by the vehicle speed sensor 62 and the azimuth change angle ΔNA (see Figure 7) measured by the inertial measurement unit 74. The control unit 78 is configured to initiate automatic turning based on the detection of an obstacle at the edge of a field by the obstacle detection unit 63, and to start automatic turning control at any desired timing. The target position for automatic turning control is the starting position Ls of the next work run, and the turning control is performed so that the vehicle's azimuth NA and the target azimuth LA coincide at the starting position Ls.

[0109] The following describes the patterns of turning around at the edge of the field. In the turning travel pattern shown in Figure 9, the machine travels along the target travel path LM with a width of W1 from left to right, and then performs a U-shaped turning travel from the end point Lf of the work travel towards the starting point Ls of the next work travel. The work width W1 is the work width of the seedling planting device W, and the work widths W1 and W2 have the same width. The same applies to the work widths W1 and W2 shown in Figures 10 and 11, which will be described later.

[0110] In the turning travel pattern shown in Figure 9, the distance W3 between the endpoint Lf or starting point Ls and the edge of the field ridge is twice the working width W1 or working width W2. Therefore, after completing the work travel along all target travel paths LM, the traveling machine C performs work travel while making two circular turns along the edge of the field ridge. The turning travel pattern shown in Figure 9 is mainly used in rice transplanters equipped with four-row or six-row seedling planting devices W.

[0111] When the mobile unit C approaches the edge of the field, the obstacle detection unit 63 detects the edge of the field over time, and after it is determined that the mobile unit C is moving away from the edge of the field, automatic turning control is initiated. The location indicated by P1 in Figure 9 is approximately the midpoint of the turning travel along the edge of the field, and is the position where the mobile unit C is closest to the edge of the field. Therefore, after the mobile unit C passes the location of P1, it is determined that the mobile unit C is moving away from the edge of the field, and automatic turning control by the control unit 78 is initiated. The same applies to the location indicated by P1 in Figure 10, which will be described later.

[0112] The timing for initiating automatic turning control may be, for example, after the mobile machine C has passed location P1, the operator may be notified via the notification unit 59 that automatic turning is possible, and the automatic turning control may be initiated by operating the start / end point setting switch 49A, the target setting switch 49B, or the automatic steering switch 50. Alternatively, the automatic turning control may be initiated automatically. Furthermore, even before the mobile machine C has passed location P1, automatic turning control may be permitted by operating the start / end point setting switch 49A, the target setting switch 49B, or the automatic steering switch 50, and after the mobile machine C has passed location P1, it may be determined that the mobile machine C has moved away from the edge of the field, and the automatic turning control may be initiated.

[0113] In the turning travel pattern shown in Figure 10, the work travel is performed along the target travel path LM with a width of W1 from left to right, and then a U-shaped turning travel is performed from the end point Lf of the work travel towards the starting point Ls of the next work travel.

[0114] In the turning travel pattern shown in Figure 10, the distance between the endpoint Lf or starting point Ls and the edge of the field ridge is the same as the working width of the seedling planting device W. Therefore, in the case of a rice transplanter with a seven-row or eight-row seedling planting device W, for example, if the turning travel along the edge of the field is performed as is, there is a risk that the front of the traveling machine C will come into contact with the edge of the field ridge. For this reason, in the turning travel pattern shown in Figure 10, after the traveling machine C reaches the endpoint Lf of the target travel path LM, the traveling machine C reverses to position Lff, and then the traveling machine C performs a U-shaped turning travel towards the starting point Ls of the next work run.

[0115] Furthermore, in the turning travel pattern shown in Figure 10, the timing at which automatic turning control is initiated is not limited to the timing previously described for the turning travel pattern shown in Figure 9. For example, the automatic turning control may be initiated when it is determined that the mobile vehicle C has moved backward from the end position Lf to position Lff. Alternatively, after the mobile vehicle C reaches the end position Lf, the automatic turning control may be performed by operating the automatic steering switch 50 or the like, which may include the backward movement from the end position Lf to position Lff.

[0116] In the turning travel pattern shown in Figure 11, the distance between the endpoint Lf or starting point Ls and the edge of the field ridge is the same as the working width of the seedling planting device W. Furthermore, the traveling device C is configured such that its turning radius is smaller than the working width of the seedling planting device W. Thus, in the turning travel pattern shown in Figure 11, after the device travels along the target travel path LM with a width of W1, the traveling device C first turns in an L-shape from the endpoint Lf of the work travel to position P1 along the edge of the field ridge. Next, the traveling device C travels straight along the edge of the field ridge to position P2. Then, from position P2 towards the starting point Ls of the next work travel, the traveling device C makes another L-shaped turning motion, completing the turning motion along the edge of the field. The turning travel pattern shown in Figure 11 is mainly used in rice transplanters equipped with a ten-row seedling planting device W.

[0117] The turning maneuver from position P2 towards the starting position Ls of the next work run is a turning maneuver in which the steering wheels 10 are steered in a direction that moves the machine C away from the edge of the field. Therefore, after the machine C passes point P2, it is determined that the machine C has moved away from the edge of the field, and the control unit 78 starts automatic turning control. As for the timing of starting automatic turning control, for example, the system may be configured to start automatic turning control when the steering handle 43 is detected to be operated toward the starting position Ls of the next work run while the machine C is traveling along the edge of the field. Alternatively, the system may be configured to start automatic turning control after the machine C has passed point P2 by operating the automatic steering switch 50 or the like. In addition, even before the mobile unit C passes the location P2, automatic turning control may be permitted by operating the start / end point setting switch 49A, the target setting switch 49B, the automatic steering switch 50, etc., and after the mobile unit C passes the location P2, it may be determined that the mobile unit C has moved away from the edge of the field ridge, and the automatic turning control may be initiated.

[0118] While automatic turning control is in operation, the steering handle 43 is configured such that even if the steering angle of the steering wheels 10 changes, the steering angle of the steering wheels 10 is not transmitted to the steering handle 43. For example, if the operation of the steering handle 43 is transmitted to the steering control unit 79 by an electrical signal, the steering control unit 79 should be configured to perform automatic turning control regardless of the operation of the steering handle 43. Also, if a clutch is interposed between the steering handle 43 and the steering wheels 10, the clutch should be configured to be disengaged while automatic turning control is in operation. Before automatic turning control is started, the driver is notified by the notification unit 59 or the warning unit 64 that automatic turning control is about to start, and is prompted to release their hands from the steering handle 43. Furthermore, even if the driver cannot operate the steering handle 43 during automatic turning control, the system may be configured to allow the driver to operate the steering handle 43 through a dedicated operating tool (not shown) or brake operation.

[0119] [Position misalignment correction process] If the mobile vehicle C deviates laterally from the target movement path LM by a predetermined range, the following positional deviation correction process is performed. As shown in Figure 12, when the mobile vehicle C is moving with its own position NM deviated laterally from the target movement path LM by a deviation amount ΔP, the control unit 78 changes the target heading LA to a heading tilted by a set inclination angle α1. In other words, when performing automatic steering control, the control unit 78 changes the target heading LA to a heading tilted by a set inclination angle α1 toward the side where the target movement path LM is located and performs automatic steering control.

[0120] In this system, the further the vehicle's position NM is from the point corresponding to the target movement path LM, the larger the set inclination angle α1 is set to be. Conversely, the closer the vehicle's position NM is to the point corresponding to the target movement path LM, the smaller the set inclination angle α1 is set to be. Also, if the vehicle speed is low, the set inclination angle α1 is set to be high, and the faster the vehicle speed, the smaller the set inclination angle α1 is set to be. However, an upper limit is set for the set inclination angle α1, so no matter how low the vehicle speed is or how large the positional deviation, the set inclination angle α1 will not exceed the set upper limit. This prevents the vehicle C from making sharp turns and becoming unstable.

[0121] When the aircraft's heading NA reaches the target heading LA tilted by a set inclination angle α1, the target heading LA is changed to a heading tilted by a less steep inclination angle α2 than α1. Furthermore, when the aircraft's heading NA reaches the target heading LA tilted by an inclination angle α2, the target heading LA is changed to a heading tilted by a less steep inclination angle α3 than α2. In this way, the aircraft C travels diagonally while the azimuth deviation with respect to the target travel path LM gradually decreases, allowing the positional deviation ΔP to be reduced rapidly.

[0122] The area corresponding to the target movement path LM described above has a region of a predetermined width (first distance) in the lateral direction on both the left and right sides of the position corresponding to the target movement path LM. In other words, a control dead zone is set for position deviation, and when the position deviation falls within the range of the control dead zone (within the range of the first distance), the target bearing LA does not tilt and is set in the direction along the original target movement path LM.

[0123] With the above configuration, the mobile vehicle C is guided to the target movement path LM, and in particular, in the automatic steering control that starts immediately after the automatic turning control described above, the positional deviation of the mobile vehicle C relative to the target movement path LM is quickly corrected.

[0124] Furthermore, the system may be configured so that the positional deviation correction control described above is not executed if a decrease in the accuracy of the positioning data from the satellite positioning unit 70 is detected. In this case, the positional deviation is not taken into consideration, and automatic steering control is performed so that the aircraft's heading NA aligns with the target heading LA in the direction along the target movement path LM.

[0125] [Display] As shown in Figure 13, the status of the machine is displayed on the screen of the display unit 48 via the notification unit 59. The display unit 48 is divided into several display areas, such as the work information area 100, the position deviation information area 101, and the vehicle speed information area 102. The work information area 100 displays the date and time of work and work results at the upper left end of the display unit 48. The position deviation information area 101 displays the amount of position deviation of the traveling machine C (own position NM) relative to the target movement path LM at the upper center. The vehicle speed information area 102 displays the vehicle speed at the upper right end. The large area other than the upper part of the display unit 48 is the position information area 104, which shows the position of the traveling machine C in the field. The small area at the left end of the position information area 104 is the steering status information area 103, which displays the status of the control device 75 in automatic steering mode or manual steering mode. A group of touch-panel operated software buttons 120 is located at the right edge of the location information area 104. Further to the right of the display unit 48, a group of physical buttons 121 is located.

[0126] The position information area 104 displays the working status of the field around the mobile unit C, the target movement path LM, and the unit symbol SY indicating the unit's own position NM. The target movement path LM during work is drawn with a thick solid line for clarity. Furthermore, areas where rice planting has already been completed are displayed with each planted seedling represented as a dot. This clearly distinguishes between areas that have been worked on and areas that have not. Note that this display of planted seedlings may also be represented by lines indicating planting rows, rather than dots.

[0127] Although not explicitly shown in Figure 13, the actual route taken by the mobile vehicle C, i.e., its trajectory, can also be displayed on the display unit 48. By comparing this trajectory with the target movement path LM, the accuracy of the automatic steering control can be checked. The trajectory is displayed on the display unit 48 based on positioning data from the satellite positioning unit 70. The vehicle symbol SY is shown as an arrow, with the pointed end indicating the direction of travel, i.e., the vehicle's heading NA. To make the azimuth deviation between the vehicle's heading NA and the target heading LA more visually clear, a pointer 110 extending from the center of the vehicle symbol SY in the direction of travel, and a direction scale 111 indicating the angular range of its direction are overlaid on the display. A boundary line 112 indicating the allowable range of the azimuth deviation is also displayed. The digital value of the azimuth deviation can also be displayed. The driver can visually confirm the positional and azimuth deviations of the mobile vehicle C relative to the target movement path LM through the display unit 48.

[0128] When the target movement path LM2 for the next process is set based on the work run along the target movement path LM, the amount of positional deviation of the traveling machine C relative to the target movement path LM2 for the next process is displayed in the positional deviation information area 101, as shown in Figure 13. The timing of when the amount of positional deviation is displayed may be during the turn run along the edge of the field from the target movement path LM to the target movement path LM2 for the next process, or after the completion of the turn run along the edge of the field.

[0129] As mentioned above, when positioning between two points is performed by DGPS in a short period of time, such as ten seconds, the error in the relative position between the two points is extremely small. However, the error in position coordinates measured over time by DGPS increases as time passes from the time when position coordinate NM3 (see Figure 8) was measured, compared to position coordinate NM3 measured immediately before turning at the edge of the field. In other words, the relative positioning accuracy with respect to position coordinate NM3 decreases with the passage of time. For this reason, when DGPS is used in the satellite positioning unit 70, the display unit 48 is configured so that the amount of position deviation is not displayed in the position deviation information area 101 if a decrease in the accuracy of the position deviation amount is detected. For example, a setting time for displaying the position deviation amount in the position deviation information area 101 may be set in advance, and the position deviation amount may not be displayed in the position deviation information area 101 once the set time has elapsed from the time when position coordinate NM3 was measured.

[0130] While the aforementioned automatic turning control is being performed, the position of the mobile vehicle C and the amount of positional deviation are not displayed in the positional deviation information area 101 and positional deviation information area 104 of the screen displayed on the display unit 48. In other words, the display unit 48 will show that automatic turning is in progress, making it easy for the driver to understand. Alternatively, the system may be configured to allow the driver to switch on or off the display of the position of the mobile vehicle C and the amount of positional deviation during automatic turning. Switching between display and non-display may be done by operating the software button group 120 or the physical button group 121. Furthermore, notification of the amount of positional deviation may be done by voice notification from the notification unit 59 or by a switch illumination or flashing indicator.

[0131] If the satellite positioning unit 70 has insufficient reception sensitivity due to factors such as a small number of navigation satellites it can acquire, there is a risk that the positioning data of the satellite positioning unit 70 may contain a large error. In such cases, the configuration may be such that the amount of position deviation is not displayed in the position deviation information area 101. Alternatively, the configuration may be such that the insufficient reception sensitivity of the satellite positioning unit 70 is notified via the notification unit 59 in the position deviation information area 101 and the position information area 104. This prompts the driver to perform the work driving manually. The notification of insufficient reception sensitivity of the satellite positioning unit 70 may also be provided by voice guidance or by a switch indicator that lights up or flashes, and it is configured to be switchable off. The notification time of the notification unit 59 may also be set and adjusted as needed. Furthermore, if the automatic steering switch 50 is operated in this state, the configuration may be such that the position deviation is not taken into consideration, and automatic steering control is performed so that the vehicle's heading NA aligns with the target heading LA.

[0132] The target movement path LM may be configured to be correctable after setting. For example, a manual operation may be performed immediately after the completion of a turn along the edge of a field, and the current machine position NM may be misaligned to the left or right relative to the target movement path LM in the forward view of the machine C. In such a case, the system may be configured to allow the operator to correct the target movement path LM by moving it horizontally in the direction of the current machine position NM in the forward view of the machine C. With this configuration, even if the misalignment of the current machine position NM relative to the target movement path LM is outside the acceptable range, the misalignment of the current machine position NM can be brought within the acceptable range relative to the target movement path LM by correcting the target movement path LM. This allows automatic steering control along the target movement path LM to be started quickly. The correction of the target movement path LM may be performed by operating the software button group 120 or by operating the physical button group 121.

[0133] [Another embodiment] The present invention is not limited to the configurations exemplified in the embodiments described above, and other representative embodiments of the present invention are exemplified below.

[0134] [1] In the embodiment described above, the target movement paths LM2 for subsequent processes are configured to be set one at a time, but the embodiment is not limited to the above. For example, as shown in Figure 14, the target movement paths LM2 for subsequent processes may be configured to be set multiple times simultaneously. In Figure 14, the target movement paths LM2(A1), LM2(A2), and LM2(A3) for subsequent processes are set at pre-set equal intervals on the unworked area side of the target movement path LM. The target movement paths LM2(A1), LM2(A2), and LM2(A3) for subsequent processes are set based on the working travel trajectory of the mobile machine C in the target movement path LM. In addition, the target movement paths LM2(B1), LM2(B2), and LM2(B3) for subsequent processes are set at equal intervals based on the working travel trajectory of the mobile machine C in the target movement path LM2(A3).

[0135] The timing for setting the target movement paths LM2(A1), LM2(A2), and LM2(A3) for subsequent processes may be set when the obstacle detection unit 63 determines the edge of the ridge near the end point Lf, or when the mobile machine C is performing a turn along the edge of the ridge towards the starting point Ls(A1), or when the mobile machine C has reached the starting point Ls(A1). Similarly, the timing for setting the target movement paths LM2(B1), LM2(B2), and LM2(B3) for subsequent processes may be set when the obstacle detection unit 63 determines the edge of the ridge near the end point Lf(A3), or when the mobile machine C is performing a turn along the edge of the ridge towards the starting point Ls(B1), or when the mobile machine C has reached the starting point Ls(B1). At the timings described above, each target movement path LM2 for the subsequent process is set by the driver operating the target setting switch 49B. However, the configuration is not limited to this, and for example, it may be set by the driver operating the automatic steering switch 50, or it may be set automatically without any operation by the driver.

[0136] In a configuration where multiple mobile work implements operate simultaneously, each mobile work implement may operate in parallel along the subsequent target movement paths LM2(A1), LM2(A2), and LM2(A3), and then operate in parallel along the subsequent target movement paths LM2(B1), LM2(B2), and LM2(B3).

[0137] [2] In the embodiment described above, the path setting unit 76 is configured such that the target movement path LM2 for the next process is set on the unworked area side of the target movement path LM, but the embodiment is not limited to the one described above. For example, if both the left and right sides of the target movement path LM are unworked areas, the configuration may be such that the target movement paths LM2(L) and LM2(R) for the next process are set on both the left and right sides of the target movement path LM, as shown in Figure 15. In this case, the configuration may be such that the machine performs a turn-around run along the edge of the field toward one of the target movement paths LM2(L) and LM2(R), and after the turn of the machine C is determined, the setting of the target movement path LM2 for the next process is finalized. Ideally, the target movement paths LM2(L) and LM2(R) for the next process are set at a distance P away from the target movement path LM, that is, at the positions indicated by the dashed lines lm(L) and lm(R) in Figure 15. In contrast, in this embodiment, the target movement paths LM2(L) and LM2(R) for the subsequent process are set to be shifted in parallel from the dashed lines lm(L) and lm(R) by a positional deviation d, corresponding to the positional deviation d of the traveling machine C.

[0138] [3] Even when the target movement path LM is set in a straight line, the actual working trajectory of the mobile machine C may meander as shown by the dashed line in Figure 16, for example, due to slippage of the mobile machine C or avoidance of obstacles in the field. In such cases, the target movement path LM2 for subsequent processes is set along the actual working trajectory of the mobile machine C. The target movement path LM2(1) for subsequent processes shown in Figure 16 meanders along the actual working trajectory of the mobile machine C. This prevents the risk of already planted seedlings in the already worked area being trampled or of unworked areas occurring between the working trajectory before and after turning along the edge of the field when working along the target movement path LM2 for subsequent processes. The actual working trajectory of the mobile unit C may be calculated based on positioning data from the satellite positioning unit 70, or it may be calculated by integrating the vehicle speed measured by the vehicle speed sensor 62 and the azimuth change angle ΔNA (see Figure 7) measured by the inertial measurement unit 74.

[0139] When the target movement path LM2 for the next process is set along the actual working trajectory of the mobile machine C, the target movement path LM2 for the next process is configured to have a more linear shape than the actual working trajectory of the mobile machine C. For example, if the working trajectory of the mobile machine C is complexly meandering relative to the target movement path LM, the target movement path LM2 for the next process will also be complexly meandering, and there is a risk that the mobile machine C will not be able to travel along the target movement path LM2 with accuracy. For this reason, the target movement path LM2(1) for the next process shown in Figure 16 is set at a position that is a set distance P away from the target movement path LM, and then a further distance Δp away from that position. The target movement path LM2(1) for the next process is set when the meandering section shown by the dashed line in Figure 16 and the meandering section of the target movement path LM2(1) are separated by a set distance P. As a result, the target movement path LM2(2) set after the setting of the target movement path LM2(1) is set to be more linear than the target movement path LM2(1), and the target movement path LM2(3) set after the setting of the target movement path LM2(2) is set to be approximately linear. Consequently, even if the actual working trajectory of the traveling machine C accidentally meanders, it will be gradually corrected to a linear shape by the subsequent target movement path LM2 set. The number of meandering sections in the target movement path LM2 between the target movement path LM shown in Figure 16 and the approximately linear target movement path LM2(3) shown at the right end of Figure 16 can be changed as appropriate.

[0140] [4] In the embodiments described above, the target movement path LM is configured to be set within a single, self-contained field, but the embodiment is not limited to those described above. For example, the target movement path LM may be configured to be set across multiple fields. In this case, the teaching path and the actual work travel trajectory relative to the target movement path LM may be stored as reference paths and used to set the target movement path LM in other fields. The reference paths may be stored in the memory of a microcomputer provided in the mobile unit C, or in the memory of an external terminal. If the reference paths are stored in the memory of an external terminal, the mobile unit C may be equipped with communication equipment capable of communicating with the external terminal via a WAN (Wide Area Network), etc., and the reference paths may be read from the memory of the external terminal to the microcomputer of the mobile unit C. Multiple reference paths may be stored in the memory of the external terminal or the microcomputer of the mobile unit C. This configuration allows the target movement path (LM) to be set without teaching the system, simply by reading the corresponding reference path for each field.

[0141] [5] The setting of the target movement path LM2 for the post-processing stage shown in the above-described embodiment may be configured so that it is not performed after the setting time has elapsed from the time the position coordinates NM3 (see Figure 8) are determined. When DGPS is used in the satellite positioning unit 70, the relative positioning accuracy with respect to the position coordinates NM3 decreases over time. For this reason, if the path setting unit 76 determines that it cannot set the target movement path LM2 for the post-processing stage accurately, it may be configured so that setting the target movement path LM2 for the post-processing stage becomes impossible.

[0142] [6] If the target movement path LM2 for the next process cannot be set, the system may be configured to notify the operator via the notification unit 59 that it is impossible to set the target movement path LM2 for the next process. The notification by the notification unit 59 may be an audible sound such as a buzzer, or it may be the illumination or flashing of an LED light provided on the center mascot 14, or it may be displayed on the display unit 48. Examples of cases where the target movement path LM2 for the next process cannot be set include when the setting path of the target movement path LM2 for the next process is located on the headland or edge of the field, when the setting position of the target movement path LM2 for the next process crosses the field boundary and enters the adjacent field, when an obstacle is detected on the setting path of the target movement path LM2 for the next process, or when a malfunction of the satellite positioning unit 70 is detected.

[0143] [7] If the mobile machine C deviates significantly from the target travel path LM by a distance greater than a preset distance, the target travel path LM may be configured not to be used for work travel. If the mobile machine C deviates significantly from the target travel path LM, it is highly likely that the operator is intentionally manipulating the mobile machine C. In such cases, a configuration that prioritizes the operator's human intervention is preferable. Of course, if a turn-around maneuver is performed along the target travel path LM after the completion of work travel along the target travel path LM, and the mobile machine C deviates significantly from the target travel path LM2 for the subsequent process by a distance greater than a preset distance (a second distance longer than the first distance), the target travel path LM2 for the subsequent process may also be configured not to be used for work travel.

[0144] [8] The route setting unit 76 may be configured to set the target movement path LM2 for the next process in conjunction with the control unit 78 and the steering control unit 79. For example, the control unit 78 may be configured to determine whether the route setting unit 76 has set the target movement path LM2 for the next process and to perform either or both of the automatic turning control and automatic driving control described above. In addition, the operator may individually decide whether to perform work along the target movement path LM2 for the next process after the machine C has performed work along the target movement path LM. For this reason, the route setting unit 76 may be configured to be switchable between a configuration in which it sets the target movement path LM2 for the next process in conjunction with the control unit 78 and the steering control unit 79, and a configuration in which it sets the target movement path LM2 for the next process independently of the control unit 78 and the steering control unit 79.

[0145] [9] The embodiment is not limited to those described above. For example, the path setting unit 76 may be configured to set the target movement path LM2 for the next process when the azimuth difference between the self-azimuth NA of the mobile machine C and the target azimuth LA of the target movement path LM exceeds a preset range. For example, the configuration may be such that when the angle of the azimuth difference becomes 90 degrees or more, the turning of the mobile machine C is determined and the target movement path LM2 for the next process is set. In this case, the target movement path LM2 for the next process may be set automatically, or it may be set by operating the target setting switch 49B or the automatic steering switch 50. Alternatively, the setting of the target movement path LM2 for the next process may be permitted by operating the target setting switch 49B or the automatic steering switch 50, and then the angle of the azimuth difference exceeds a preset range and the target movement path LM2 for the next process is set.

[0146]

[10] In addition to the target setting switch 49B, other operating tools for setting the target movement path LM2 for the subsequent process may include, for example, the software button group 120 on the display unit 48 or the physical button group 121 located to the right of the display unit 48. In other words, the operating tool may be a dedicated operating tool, or it may be an existing button switch or lever with added functionality.

[0147]

[11] In the embodiment described above, the target for the next process is the target movement path LM2 for the next process, but the target for the next process may be, for example, the starting position Ls after turning at the edge of the ridge. When the operator operates the target setting switch 49B, the target movement path LM2 for the next process, which is parallel to the target movement path LM that has already been traveled, may be set with respect to the starting position Ls. Furthermore, the target for the next process may be a part of the target movement path LM2 for the next process, for example, an area of ​​the target movement path LM2 that is a few meters from the starting position Ls. Moreover, when the mobile machine C has completed all of its work along the target movement path LM, or when refueling is required in the middle of rice planting, the target for the next process may be the headland area along the edge of the ridge.

[0148]

[12] In addition to the rice transplanters described above, the present invention is applicable to other direct seeding machinery, including direct seeders. Furthermore, the present invention is applicable to agricultural machinery other than direct seeding machinery, such as tractors and combine harvesters. [Industrial applicability]

[0149] The present invention is applicable to mobile implements that perform work along a target movement path in a field. [Explanation of Symbols]

[0150] 43: Steering handle (artificial operating tool) 59: Information Department (Information Methods) 63: Obstacle detection unit (ridge edge detection means) 70: Satellite positioning unit (position detection means) 76: Route setting section 78: Control Unit (Control Unit) 79: Steering control section (control section) C: Mobile body W: Seedling planting device (work device) LM: Target movement path LM2: Target movement path for downstream processes (target for downstream processes)

Claims

[Claim 1] A vehicle that travels across the field, A work device for performing work on the field, It is equipped with a control unit capable of automatic turning control to a target travel path for subsequent processes, When transitioning from the target travel path to the target travel path for the subsequent process, the control unit can perform the automatic turning control. A mobile work machine that, after reaching the end of the target travel path, reverses along the target travel path, and then the automatic turning control by the control unit is automatically initiated.

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