Field work vehicle

Abstract

To prevent unnecessary restart of automatic traveling from being automatically performed after the automatic traveling is stopped.SOLUTION: The field work vehicle includes an automatic travel control section 511 configured to execute automatic travel along a target travel route as a travel target in straight travel, a first automatic travel start command section 535 configured to issue a start command for starting automatic travel to the automatic travel control section 511 based on a manual operation, an automatic travel stop command section 536 configured to issue a stop command for stopping automatic travel to the automatic travel control section 511 based on a manual operation, a second automatic travel start command section 537 configured to issue an automatic start command for starting automatic operation travel to the automatic travel control section 511 without a start command when an automatic travel condition is satisfied, and an automatic travel check section 538 configured to prohibit the second automatic travel start command section 537 from issuing an automatic start command or invalidate an automatic start command based on a vehicle travel state.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a field work vehicle that performs field work using a work implement while transitioning from straight travel, through turning travel, to the next straight travel. [Background technology]

[0002] The field work vehicle disclosed in Patent Document 1 is a work vehicle that performs field work by combining straight-line driving and turning driving to transition from straight-line driving to the next straight-line driving, and this field work vehicle is equipped with a route setting unit that sets a target driving route that serves as a driving target for straight-line driving, an automatic steering switch that outputs an automatic steering request based on operation by the driver, and an automatic steering control unit that starts automatic steering driving if it determines that automatic steering driving is possible in response to the automatic steering request that requests driving along the target driving route with automatic steering. During teaching driving, the route setting unit sets a driving route parallel to the teaching route calculated from the set start and end positions as the target driving route. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2019-176801 Summary of the Invention [Problem to be solved by the invention]

[0004] Because it may be necessary to temporarily stop or change direction during straight-ahead driving (auto-steering driving) using automatic driving (auto-steering), such field work vehicles also employ an automatic steering stop switch to stop automatic steering driving. In the field work vehicle disclosed in Patent Document 1, the driver must operate the automatic steering switch to resume straight-ahead driving (auto-steering driving) using automatic steering after stopping. To eliminate this inconvenience, it is desirable to provide a function that automatically starts automatic driving when the conditions for automatic steering driving (auto-driving) are met. However, simply combining the automatic driving stop switch with the function that automatically starts automatic driving can result in the inconvenience of automatically resuming automatic driving in a vehicle driving state that the driver does not intend, such as before starting a turn.

[0005] For this reason, there is a demand for preventing unnecessary automatic restart of automatic driving after the automatic driving has been stopped. [Means for solving the problem]

[0006] The field work vehicle according to the present invention performs field work using a work implement while transitioning from straight-line driving to turning driving and then to the next straight-line driving, and comprises a traveling body, a route setting unit that sets a target driving route that serves as a driving target for the straight-line driving, an automatic driving control unit that executes automatic driving along the set target driving route, a first automatic driving start command unit that issues a start command to the automatic driving control unit to start the automatic driving based on human operation, an automatic driving stop command unit that issues a stop command to the automatic driving control unit to stop the automatic driving based on the human operation, a second automatic driving start command unit that issues an automatic start command to the automatic driving control unit to start automatic operated driving without the start command if automatic driving conditions are met, and an automatic driving restraint unit that prohibits the second automatic driving start command unit from issuing the automatic start command or disables the automatic start command.

[0007] According to this configuration, if automatic driving is stopped by a driver's operation while the vehicle is automatically traveling along a set target driving route, automatic driving can be resumed (started) along the same target driving route by the driver's operation, but the automatic resumption of automatic driving by the second automatic driving start command unit is prohibited (cancelled) or disabled (canceled) by the automatic driving restraint unit based on a specific vehicle driving state. In other words, this avoids the inconvenience of automatic resumption of automatic driving in a vehicle driving state in which resumption of automatic driving is not desired. Note that when it is desired to resume automatic driving along the same target driving route, the first automatic driving start command unit can start automatic driving based on a human operation.

[0008] Restarting the automatic driving that was stopped halfway along the target driving route is particularly inappropriate when the work driving on the set target driving route is in the final process and the vehicle is in the process of preparing for turning. For this reason, the present invention proposes that the automatic driving restraint unit be configured to prohibit the issuance of the automatic start command or invalidate the automatic start command on the same target driving route where the automatic driving was temporarily stopped.

[0009] When the working device finishes turning in a non-working attitude, automatic driving begins along the target driving path set for the next straight driving. Before this automatic driving begins, the working device is changed from a non-working attitude to a working attitude. Therefore, the vehicle driving state before the working device is changed from a non-working attitude to a working attitude is suitable for the automatic start of automatic driving. In other words, a vehicle driving state in which the working device has not been changed to a non-working attitude is not suitable for the automatic start of automatic driving. For this reason, the present invention proposes that the working device be capable of changing its attitude between a non-working attitude and a working attitude, and that the automatic driving restraint unit prohibits the issuance of the automatic start command or disables the automatic start command unless the working device has been changed to the non-working attitude.

[0010] For example, if the field work vehicle is a rice transplanter, the working device is a seedling planting device, and therefore the vehicle running state in which the seedling planting device is raised to an elevated position, which is a non-working posture, is considered to be the vehicle running state suitable for the automatic start of automatic travel. For this reason, the present invention proposes that the working device is a seedling planting device that can be raised and lowered between an elevated position, which is a non-working posture, and a lowered position, which is a working posture, and that the automatic travel restraint unit prohibits the issuance of the automatic start command or disables the automatic start command unless the seedling planting device is in the elevated position.

[0011] From a similar perspective, it is proposed that a preferred embodiment of the present invention is such that the work device has a leveling device (such as a leveling float or leveling roller) that can be raised and lowered between a lowered position where it touches the rice field surface and an elevated position where it is lifted off the rice field surface, and the working posture of the work device is created by the leveling device in the lowered position, and the automatic travel restraint unit prohibits the issuance of the automatic start command or disables the automatic start command unless the leveling device has lifted off the rice field surface. Furthermore, from a similar point of view, as a preferred embodiment of the present invention, it is proposed that the work device can be raised and lowered by a link mechanism, and that the automatic driving restraint unit prohibits the issuance of the automatic start command or disables the automatic start command based on the raised and lowered position of the work device detected by a lifting detection sensor.

[0012] The function of the second automatic driving start command unit, which starts automatic driving without a start command based on human operation, is beneficial, especially for unskilled operators. However, depending on the field conditions and the type of implement, the disadvantages may outweigh the benefits. For this reason, the present invention proposes providing a function switching device that enables or disables the function of the second automatic driving start command unit. [Brief explanation of the drawings]

[0013] [Figure 1] FIG. [Figure 2] FIG. 1 is a schematic diagram illustrating the raising and lowering of the planting device and the ground leveling float. [Figure 3]FIG. 2 is a schematic diagram showing an outline of an automatic driving mechanism. [Figure 4] FIG. 2 is a functional block diagram of a control system. [Figure 5] FIG. 1 is a plan view illustrating the travel of a rice transplanter using automatic travel control. [Figure 6] 10 is a flowchart showing an example of travel control of a rice transplanter using automatic travel control. DETAILED DESCRIPTION OF THE INVENTION

[0014] The following describes a rice transplanter as an example of one embodiment of a field work vehicle of the present invention. In this embodiment, unless otherwise specified, "front" (the direction of arrow F shown in FIG. 1) means the front in the fore-and-aft direction (traveling direction) of the machine body, and "rear" (the direction of arrow B shown in FIG. 1) means the rear in the fore-and-aft direction (traveling direction) of the machine body. Furthermore, left-right or lateral direction means the left-right direction of the machine body (machine body width direction) perpendicular to the fore-and-aft direction of the machine body, and "left" means the direction toward the front of the paper in FIG. 1, and "right" means the direction toward the back of the paper in FIG. 1.

[0015] [Overall structure] As shown in Figure 1, the rice transplanter is equipped with a riding four-wheel drive traveling body 1. The traveling body 1 is equipped with a parallel quadruple linkage mechanism 13 connected to the rear of the traveling body 1 so that it can be raised and lowered and swung, a hydraulic lifting cylinder 13a that drives the linkage mechanism 13 to swing, a seedling planting device 3A connected to the rear end region of the linkage mechanism 13 so that it can roll, and a fertilizer applicator 3B installed from the rear end region of the traveling body 1 to the seedling planting device 3A. In this embodiment, the seedling planting device 3A and the fertilizer applicator 3B are the working devices 3 provided on the field work vehicle of the present invention.

[0016] The traveling vehicle body 1 includes a wheeled traveling device 12, an engine 2A, and a hydraulic continuously variable transmission 2B, which serves as the main transmission. The continuously variable transmission 2B is, for example, an HST (Hydro-Static Transmission), and changes the power (rotation speed) output from the engine 2A by adjusting the angles of a motor swash plate and a pump swash plate. The traveling device 12 has left and right front wheels 12A that function as steering wheels for changing the vehicle's orientation, and left and right rear wheels 12B that cannot be steered.

[0017] As shown in Figure 1, the traveling vehicle body 1 has a driver's section 14 in its rear side area. The driver's section 14 is equipped with a steering wheel 10 for steering the front wheels, a main speed change lever 7A that adjusts the vehicle speed by changing the speed of the continuously variable transmission 2B, an auxiliary speed change lever 7B that enables speed change operation of the auxiliary speed change lever, an operation control lever 11 that operates to raise and lower the seedling planting device 3A, and a driver's seat 16 for passengers (driver, worker, manager). Furthermore, in front of the driver's section 14, a spare seedling storage table that stores spare seedlings is supported on a spare seedling support frame 17.

[0018] The seedling planting device 3A is raised and lowered by a link mechanism 13 that is displaced by the extension and retraction of a lifting cylinder 13a. As shown in FIG. 2, the lifting cylinder 13a is extended and retracted by a hydraulic valve 13b controlled by a control command from the control device CU. The raised and lowered position of the seedling planting device 3A can be detected, for example, by a lifting position sensor S2, which functions as a lifting detection sensor that detects the raised and lowered position of the seedling planting device 3A. The soil leveling float 15 is attached to the frame of the seedling planting device 3A by a swing link 15A so that it can swing up and down. The swing angle of the soil leveling float 15 is detected by a float swing detection sensor that also functions as a ground contact sensor S1 and sent to the control device CU. When the height of the seedling planting device 3A relative to the field surface (the surface of the paddy field, which is the muddy soil beneath the paddy field surface) changes, the ground contact reaction force acting on the soil leveling float 15 causes the front end of the soil leveling float 15 to swing up and down relative to the frame of the seedling planting device 3A. The seedling planting device 3A, together with the soil leveling float 15, can be moved by the lifting cylinder 13a between a lowered position as a working position and an elevated position as a non-working position. A soil leveling rotor may be used instead of the soil leveling float 15, or both the soil leveling float 15 and the soil leveling rotor may be used. In this specification, the soil leveling float 15 and the soil leveling rotor are collectively referred to as the soil leveling device.

[0019] The rice transplanter is further equipped with a positioning unit 8. The positioning unit 8 outputs positioning data for calculating the position and orientation of the traveling body 1. The positioning unit 8 includes a satellite positioning module 81 that receives radio waves from satellites of the Global Navigation Satellite System (GNSS), and an inertial measurement module 82 that detects the inclination and acceleration of the three axes of the traveling body 1. The positioning unit 8 is supported on the top of the spare seedling support frame 17.

[0020] As shown in Fig. 3, the traveling vehicle body 1 is equipped with a steering mechanism 40 that can automatically drive the left and right front wheels 12A. The steering mechanism 40 is equipped with a steering operation shaft 44, a pitman arm 41, left and right linkage mechanisms 42 that are interlocked and connected to the pitman arm 41, a steering motor 46, and a gear mechanism 43. The steering operation shaft 44 is interlocked and connected to the steering wheel 10 via a clutch 47. The pitman arm 41 is configured to swing in accordance with the rotation of the steering operation shaft 44. The gear mechanism 43 interlocks and connects the steering motor 46 to the steering operation shaft 44.

[0021] The steering operation shaft 44 is interlocked and connected to the left and right front wheels 12A via a pitman arm 41 and left and right linkage mechanisms 42. A steering angle sensor 45 consisting of a rotary encoder is provided at the lower end of the steering operation shaft 44, and the amount of rotation of the steering operation shaft 44 is detected by the steering angle sensor 45.

[0022] When the steering mechanism 40 is operated automatically during automatic driving, the steering motor 46 is driven, and the steering shaft 44 is rotated by the driving force of the steering motor 46, thereby changing the steering angle of the front wheels 12A. When automatic driving is not performed, the steering mechanism 40 can be rotated by manually operating the steering wheel 10.

[0023] Next, we will explain the positioning unit 8, which is also used for automatic driving control. As shown in Figs. 1 and 4, this rice transplanter is equipped with a satellite positioning module 81 and an inertial measurement module 82 as the positioning unit 8. The satellite positioning module 81 has a satellite positioning function that determines the position of the vehicle using a satellite positioning system (GNSS: Global Navigation Satellite System) that receives radio waves from satellites to detect the position of the vehicle. The inertial measurement module 82 includes a triaxial gyro sensor and a triaxial acceleration sensor.

[0024] As shown in FIG. 1, the satellite positioning module 81 including the satellite positioning antenna is attached to the spare seedling support frame 17 via a support bracket.

[0025] The inertial measurement module 82 has a gyro sensor and an acceleration sensor, and can detect the angular velocity of the turning angle of the traveling vehicle body 1, and can obtain the angular displacement of the vehicle body orientation by integrating the angular velocity. In addition to the angular velocity of the turning angle of the traveling vehicle body 1, the inertial measurement module 82 can also measure the angular velocity of the left and right tilt angle of the traveling vehicle body 1 and the front and rear tilt angle of the traveling vehicle body 1. The inertial measurement module 82 is disposed below and behind the driver's seat 16, in a low position in the center of the traveling vehicle body 1 in the width direction. The inertial measurement module 82 may be disposed in the same position as the satellite positioning module 81.

[0026] Figure 4 shows the functions of the automatic driving control system of the rice transplanter in the form of a functional block diagram. The control unit CU is equipped with an input / output processing unit 50 as an input / output interface. The input / output processing unit 50 is connected to various devices such as a state detector group 70 and a manual operation tool group 90. In this functional block diagram, the positioning unit 8 is connected to the control unit CU via an on-board LAN. An alarm device 73 receives an alarm signal from an alarm unit 72 connected to the control unit CU via an on-board LAN.

[0027] The status detector group 70, which is made up of various sensors and switches, includes a traveling equipment status detector 74 and a work equipment status detector 75. In addition to the steering angle sensor 45 described above, the traveling equipment status detector 74 includes sensors that detect the traveling status, such as a vehicle speed sensor, an engine RPM sensor, a brake pedal detection sensor, and a parking brake detection sensor (not shown). The work equipment status detector 75 includes sensors that detect the status of various components that make up the seedling planting device 3A, a sensor that detects the elevation position of the seedling planting device 3A, a sensor that detects the number of seedlings on the seedling tray, and a sensor that detects the attitude of the soil leveling float 15.

[0028] A group of manual operating devices 90, consisting of operating levers, switches, buttons, volumes, etc., is manually operated by the driver to give control commands, and these operating commands are input to the control unit CU. The group of manual operating devices 90 includes, as devices particularly relevant to the present invention, a start and end point setting switch 91, an automatic driving start switch 92, an automatic driving stop switch 93, and a function changeover switch 94 as a function changeover operating device. In Fig. 4, the switches are abbreviated as SW.

[0029] The control device CU includes a vehicle position calculation unit 56, a driving control unit 51, a work control unit 52, an automatic driving management unit 53, and the like.

[0030] The vehicle position calculation unit 56 calculates the map coordinates (vehicle position) of the traveling vehicle body 1 and the direction (azimuth) of the traveling vehicle body 1 based on the positioning data successively sent from the positioning unit 8. At this time, the vehicle position can be converted to the position of a specific point of the traveling vehicle body 1 (for example, the center of the vehicle body or the work center of the seedling planting device 3A).

[0031] The travel control unit 51 provides steering control signals and vehicle speed control signals to the steering mechanism 40 and other travel devices. Since this rice transplanter can perform rice planting work by either automatic or manual travel, the travel control unit 51 includes an automatic travel control unit 511 and a manual travel control unit 512.

[0032] The work control unit 52 controls the lifting and lowering of the seedling planting device 3A and the driving of the seedling planting device 3A as the traveling body 1 travels.

[0033] An automatic driving mode is set to perform automatic driving, and a manual driving mode is set to perform manual driving. When the automatic driving mode is set, the automatic driving control unit 511 receives automatic driving data (such as steering amount) from the automatic driving management unit 53.

[0034] The automatic driving management unit 53 includes a teaching route calculation unit 531, a route setting unit 532, a deviation amount calculation unit 533, a steering amount calculation unit 534, a first automatic driving start command unit 535, an automatic driving stop command unit 536, a second automatic driving start command unit 537, and an automatic driving restraint unit 538.

[0035] The teaching path calculation unit 531 calculates data of a reference path defined through teaching travel. The path setting unit 532 sets a target travel path (a path that serves as a travel target for straight-ahead automatic travel) that serves as a target for automatic travel based on the data of the reference path. The deviation amount calculation unit 533 calculates the position deviation and azimuth deviation of the traveling vehicle body 1 from the target travel path. The steering amount calculation unit 534 calculates a steering amount that reduces the position deviation and azimuth deviation.

[0036] The first automatic driving start command unit 535 issues a start command to the automatic driving control unit 511 to start automatic driving, which automatically drives the target driving route set by the route setting unit 532, based on an operation on the automatic driving start switch 92, which is one of the manual operation tools. The automatic driving stop command unit 536 issues a stop command to the automatic driving control unit 511 to stop automatic driving, based on an operation on the automatic driving stop switch 93, which is one of the manual operation tools. The second automatic driving start command unit 537 issues an automatic start command to the automatic driving control unit 511 to start automatic driving without a start command if the automatic driving conditions are met. The automatic driving restraint unit 538 prohibits the second automatic driving start command unit 537 from issuing the automatic start command or disables the automatic start command, based on the vehicle driving state.

[0037] The driver can start automatic driving at his / her own discretion using the function of the first automatic driving start command unit 535. Furthermore, even if automatic driving is started by the first automatic driving start command unit 535 or the second automatic driving start command unit 537, the driver can stop automatic driving at his / her own discretion using the function of the automatic driving stop command unit 536. There are various reasons for stopping automatic driving midway along the target driving route, such as field conditions, vehicle driving conditions, and work conditions, and therefore, the decision to stop automatic driving in this way is left to the driver's discretion.

[0038] The second automatic driving start command unit 537 determines whether or not automatic driving along the set target driving route can be performed, and if automatic driving becomes possible (the automatic driving conditions are met), it automatically issues an automatic start command. At this time, some examples of events that are considered to be impossible to automatically drive are as follows: (1) A deviation in direction between the traveling vehicle body 1 and the target traveling route is equal to or greater than a predetermined value. (2) A positional deviation of a predetermined value or more between the traveling vehicle body 1 and the target traveling route. (3) A steering angle of the front wheels 12A greater than a predetermined value. (4) The vehicle 1 stops or travels at an inappropriate speed. (5) Poor control of steering motor 46. (6) Detecting malfunction of the operating devices in the steering mechanism 40. (7) Mechanical malfunction of the steering mechanism 40. (8) Malfunction of the positioning unit 8 and communication failure.

[0039] Examples of vehicle driving states in which the automatic driving restraint unit 538 prohibits the second automatic driving start command unit 537 from issuing an automatic start command are shown below. (1) Issuance of an automatic start command on the same target driving route where automatic driving has been stopped is prohibited. (2) Unless the seedling planting device 3A, which is an example of the working device 3, is changed to a non-working position, the issuance of an automatic start command is prohibited. (3) The issuance of an automatic start command is prohibited unless the leveling float 15 has left the paddy field contact area. (4) When a soil leveling rotor is used instead of the soil leveling float 15, the issuance of an automatic start command is prohibited or the automatic start command is invalidated unless the soil leveling rotor leaves the paddy field contact area. Also, when both the soil leveling float 15 and the soil leveling rotor are used, the issuance of an automatic start command may be prohibited or the automatic start command may be invalidated unless at least one of them leaves the paddy field contact area, or the issuance of an automatic start command may be prohibited or the automatic start command may be invalidated unless both of them leave the paddy field contact area.

[0040] As shown in Fig. 6, this rice transplanter alternates between traveling along a straight path while planting seedlings, and turning near the edge of the paddy field to move to a straight path for the next seedling planting trip. In this case, the first straight path is a manually steered teaching path, and the subsequent straight paths are target travel paths set by the path setting unit 532 based on information about the teaching path so as to run parallel to the teaching path, and are indicated by the symbols LM(1) to LM(6) in Fig. 6.

[0041] To start seedling planting work, the driver positions the traveling vehicle body 1 at the start position Ts of the ridge in the field and operates the start / end point setting switch 91. At this time, the control device CU is set to manual steering mode. Then, while manually steering, the driver drives the traveling vehicle body 1 from the start position Ts along the straight line of the ridge on the side of the field to the end position Tf near the ridge on the opposite side, and then operates the start / end point setting switch 91 again. This executes the teaching process. That is, a teaching path connecting the start position Ts and the end position Tf is set from the position coordinates of the start position Ts and the position coordinates of the end position Tf based on the positioning data acquired by the satellite positioning module 81. The direction along this teaching path is set as the reference target orientation. The position coordinates at the end position Tf may be calculated not only based on the positioning data from the satellite positioning module 81, but also based on the distance from the start position Ts based on a vehicle speed sensor (not shown) and the orientation information of the traveling vehicle body 1 based on the inertial measurement module 82. Furthermore, the traveling of the traveling vehicle body 1 between the start position Ts and the end position Tf may be a work traveling involving rice planting work, or may be a non-work traveling.

[0042] After the teaching path has been set, a 180-degree turn is performed to move to the start position Ls adjacent to the teaching path, where the first target driving path: LM(1) is set. The turn is performed by manual steering, in which the driver manually operates the steering wheel 10.

[0043] When this turning travel is completed, the target travel route: LM(1) is set by the route setting unit 532. When the traveling vehicle body 1 approaches the set target travel route: LM(1), the driver operates the automatic travel start switch 92 to cause the first automatic travel start command unit 535 to function, or the function changeover switch 94 to cause the second automatic travel start command unit 537 to function, thereby starting automatic travel and executing automatic travel along the target travel route: LM(1).

[0044] When the automatic traveling, which is the work traveling on the target traveling route: LM(1), is completed, that is, when the traveling vehicle body 1 reaches the end position Lf(1) of the target traveling route: LM(1), turning traveling is performed. Next, the route setting unit 532 sets the next target traveling route: LM(2) adjacent to the unworked area side of the previous target traveling route: LM(1), and automatic traveling is performed along this newly set target traveling route: LM(2).

[0045] After the traveling vehicle body 1 reaches the end position Lf(2) of the target traveling route LM(2), the same process is repeated to set the target traveling route after turning traveling and the work traveling in the order of LM(3), LM(4), LM(5), and LM(6).

[0046] During autonomous driving, information on the vehicle's position is acquired over time by the satellite positioning module 81. Furthermore, the vehicle speed is calculated, and the relative heading change angle is measured over time by the inertial measurement module 82. The deviation amount calculation unit 533 calculates the vehicle's heading from the point where autonomous driving started over time by integrating the heading change angle. The deviation amount calculation unit 533 then calculates the heading deviation between the vehicle's heading and the target heading. The steering amount calculation unit 534 calculates a steering amount so that the vehicle's heading matches the target heading, and provides this to the autonomous driving control unit 511. The autonomous driving control unit 511 drives the steering motor 46 based on the provided steering amount. As a result, the traveling vehicle body 1 automatically travels accurately along the target driving route.

[0047] Next, an example of a travel control routine for the rice transplanter in which the second automatic travel start command unit 537 is set to function by the function changeover switch 94 will be described with reference to FIG.

[0048] First, teaching travel is performed (#01), and when turning travel is performed, a target travel route is set (#02).

[0049] A check is made to see if the automatic driving conditions, which are the conditions for issuing an automatic start command by the second automatic driving start command unit 537, are met (#10). If the automatic driving conditions are met (Yes branch at #10), the C flag is set to "ON" (#11), and automatic driving begins (#20).

[0050] When automatic driving starts, it is checked whether an automatic driving stop command has been issued during automatic driving (#21). If an automatic driving stop command has not been issued (NO branch in #21), this automatic driving continues until it is confirmed in step #22 that the target driving route has been traveled.

[0051] If the check in step #21 indicates that an automatic driving stop command has been issued (Yes branch in #21), automatic driving is stopped and non-automatic driving (manual steering driving) is started (#30). In non-automatic driving, the automatic driving start switch 92 is operated, and it is checked whether the first automatic driving start command unit 535 has issued a start command (#31). If a start command has been issued (Yes branch in #31), automatic driving is resumed (#32), and the process proceeds to step #22.

[0052] If the check in step #31 shows that a start command has not been issued (No branch in #31), it is checked whether the conditions for issuing an automatic start command by the second automatic driving start command unit 537 (automatic conditions) are met (#33). If the automatic conditions are met (Yes branch in #33), it is further checked whether the C flag is "OFF" (#34). In the example of this flowchart, since the C flag is set to "ON" in step #11, this step #34 has only one option, the Yes branch, and issuing an automatic start command by the second automatic driving start command unit 537 is prohibited (#35). Next, it is checked whether traveling along the target traveling route has been achieved (#36). Even if the No branch is taken in steps #33 and #34, it is still checked in step #36 whether traveling along the target traveling route has been achieved.

[0053] If the checks in steps #22 and #36 show that travel along the target travel path has been achieved, preparations for turning travel (for example, transitioning the seedling planting device 3A to a non-working position) are made (#40), the C flag is set to "OFF" (#41), and turning travel begins (#42). Once turning travel is complete (Yes branch in #43), a check is made to see if all straight travel has been completed (#44). If not completed (No branch in #44), the routine jumps to step #02, where the next target travel path is set. If all straight travel has been completed (Yes branch in #44), this routine ends.

[0054] [Another embodiment] (1) The functional block diagram of Figure 4 showing the control system in the above-described embodiment is for explanatory purposes, and each functional unit constructed in the control device CU, particularly each functional unit in the automatic driving management unit 53, may be further divided or combined.

[0055] (2) In this specification, the automatic driving of the field work vehicle has been referred to as automatic driving, but this automatic driving also includes automatic steering control in which steering is performed automatically, vehicle speed control in which vehicle speed is automatically controlled, automatic work control in which the work implement 3 is automatically controlled, and the like. In the present invention, automatic driving control may be automatic steering control in which only steering control is performed automatically, or may include vehicle speed control and automatic work control in addition to automatic steering control. Note that when automatic driving control is considered to be automatic steering control, the term "automatic driving" used in this specification can be replaced with "automatic steering."

[0056] (3) In the above-described embodiment, a rice transplanter is used as the field work vehicle, but the present invention can also be applied to other field work vehicles, such as chemical sprayers, combine harvesters, tractors, and mowers.

[0057] The configurations disclosed in the above embodiments (including other embodiments, the same applies below) can be applied in combination with configurations disclosed in other embodiments, as long as no contradiction arises. Furthermore, the embodiments disclosed in this specification are examples, and the embodiments of the present invention are not limited to these, and can be modified as appropriate within the scope that does not deviate from the purpose of the present invention. [Industrial Applicability]

[0058] The present invention is applicable to a field work vehicle that performs field work using a work implement while automatically traveling. [Explanation of symbols]

[0059] 1: Running vehicle 3: Work equipment 3A: Seedling planting device 51: Driving control unit 52: Work control section 53: Autonomous Driving Management Unit 56: Vehicle position calculation unit 70: State detector group 90:Artificial operating tools group 91: Start and end point setting switch 92: Automatic driving start switch 93: Automatic stop switch 94: Function switch 511: Automatic driving control unit 512: Manual driving control unit 531: Teaching path calculation unit 532: Route setting section 533: Deviation amount calculation unit 534: Steering amount calculation unit 535: First automatic driving start command unit 536: Automatic driving stop command unit 537: Second automatic driving start command unit 538:Autonomous Driving Control Department CU: Control unit

Claims

1. A field work vehicle that performs field work using a work implement while transitioning from straight travel to turning travel and then to the next straight travel, A running vehicle body, a route setting unit that sets a target travel route that is a travel target for the straight-ahead travel; an automatic driving control unit that executes automatic driving along the set target driving route; a first automatic driving start command unit that issues a start command to the automatic driving control unit to start the automatic driving based on a human operation; an automatic driving stop command unit that issues a stop command to the automatic driving control unit to stop the automatic driving based on the human operation; a second automatic driving start command unit that issues an automatic start command to the automatic driving control unit to start automatic operation driving without the start command if an automatic driving condition is met; an automatic driving restraint unit that prohibits the second automatic driving start command unit from issuing the automatic start command or invalidates the automatic start command based on a vehicle driving state; A field work vehicle equipped with the above.

2. The field work vehicle according to claim 1 , wherein the automatic travel restraint unit prohibits the issuance of the automatic start command or invalidates the automatic start command on the same target travel route where the automatic travel has been temporarily stopped.

3. 2. The field work vehicle according to claim 1, wherein the working device is capable of changing its posture between a non-working posture and a working posture, and the automatic travel restraint unit prohibits the issuance of the automatic start command or disables the automatic start command unless the working device has changed its posture to the non-working posture.

4. 2. The field work vehicle according to claim 1, wherein the working device is a seedling planting device that can be raised and lowered between an elevated position that is a non-working position and a lowered position that is a working position, and the automatic travel restraint unit prohibits the issuance of the automatic start command or disables the automatic start command unless the seedling planting device is in the elevated position.

5. 2. A field work vehicle according to claim 1, wherein the work device has a ground leveling device that can be raised and lowered between a lowered position where it touches the rice field surface and an elevated position where it is clear of the rice field surface, the work posture of the work device is created by the ground leveling device in the lowered position, and the automatic travel restraint unit prohibits the issuance of the automatic start command or disables the automatic start command unless the ground leveling device has cleared the rice field surface.

6. 2. The field work vehicle according to claim 1, wherein the work device can be raised and lowered by a link mechanism, and the automatic travel restraint unit prohibits the issuance of the automatic start command or disables the automatic start command based on the raised or lowered position of the work device detected by a lift detection sensor.

7. The farm work vehicle according to any one of claims 1 to 6, further comprising a function switching device for enabling or disabling the function of the second automatic travel start command unit.

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