Field operation vehicle

Abstract

A field work vehicle travels along a surrounding travel path set in an outer peripheral region of a field and a reciprocating travel path comprising an inner path (IRS) set in an inner region inside the outer peripheral region and a turning path, and is provided with: a vehicle body position calculation unit for calculating a vehicle body position; a vehicle body deviation calculation unit that calculates the amount of deviation of the vehicle body with respect to the internal path (IRS) or a target newly set so as to be different from the internal path (IRS), on the basis of the internal path (IRS), which is the target travel path, and the vehicle body position; and an automatic travel control unit that has a turning deviation correction control mode in which, when the amount of deviation occurring when transitioning from the turning path to the internal path (IRS) exceeds the allowable deviation range, the amount of deviation is reduced using at least the backward movement.

Description

Technical Field

[0001] The present invention relates to a field operation vehicle that automatically travels with a set travel path in a field as a control target. Background Art

[0002] Patent Document 1 discloses a rice transplanter equipped with an automatic steering unit that steers a traveling body along a target travel path based on the position of the own vehicle and the orientation of the traveling body relative to the target travel path. When the rice transplanter transfers from a turning travel realized by manual steering to a straight travel along the target travel path realized by automatic steering, if the orientation of the traveling body exceeds a specified allowable range, the transfer of the automatic steering unit to automatic steering travel is prohibited.

[0003] Prior Art Documents

[0004] Patent Documents

[0005] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2016-024541

[0006] In the rice transplanter of Patent Document 1, when entering the next linear travel path after a turning travel for changing the direction, if the orientation of the body exceeds the specified allowable range, it is necessary to correct the posture of the body by manual steering of the driver. In unmanned automatic travel without a driver on board, it is necessary to stop the travel or perform a deviation correction travel with a large change in the posture of the body while continuing to move forward to make the body follow the travel path. When performing such a deviation correction travel while performing a rice seedling transplanting operation, an uneven rice seedling transplanting trajectory is generated. In addition, when performing a deviation correction travel without performing a rice seedling transplanting operation, a rice seedling missing area is generated. Summary of the Invention

[0007] In view of the above actual situation, an object of the present invention is to provide an automatically traveling field operation vehicle that can effectively eliminate a large deviation of the vehicle body even when entering the next travel path after a turning travel for changing the direction.

[0008] The field operation vehicle of the present invention travels along a circular travel path and a reciprocating travel path, wherein the circular travel path is set in an outer peripheral area along the outer periphery of the field, and the reciprocating travel path is composed of an inner path and a turning path set in an inner area inside the outer peripheral area. The field operation vehicle includes: a vehicle body position calculation unit that calculates the vehicle body position; a vehicle body deviation calculation unit that calculates the deviation amount of the vehicle body relative to the inner path or a target newly set in a manner different from the inner path based on the inner path as the target travel path and the vehicle body position; and an automatic travel control unit having a turning deviation correction control mode as follows: when the deviation amount generated when transferring from the turning path to the inner path exceeds the deviation allowable range, at least use reverse to reduce the deviation amount.

[0009] According to this structure, during automatic travel, when transferring from the turning path to the inner path, if the deviation amount relative to the inner path or a target newly set in a manner different from the inner path exceeds the deviation allowable range, enter the inner path as the operation travel path in a manner that at least uses reverse to reduce the deviation amount, so that operation travel can be performed from the starting point of the inner path. Therefore, if the field operation vehicle is a rice transplanter, the generation of an uneven rice seedling planting trajectory and a rice seedling missing area can be avoided. Other field operation vehicles can also perform good field operations.

[0010] In order to perform automatic travel on the reciprocating travel path composed of the inner path and the turning path, in the present invention, the automatic travel control unit further has a path deviation correction control mode as follows: reduce the deviation amount during forward travel along the inner path. That is, the automatic travel control unit has two different deviation correction control modes, namely, a first deviation correction control mode as this path deviation correction control mode and a second deviation correction control mode as the above-mentioned turning deviation correction control mode. Thereby, the field operation vehicle can automatically travel on all inner paths and turning paths.

[0011] The appropriate posture of the vehicle body (field operation vehicle) required for appropriately performing automatic travel along the target travel path is defined by an azimuth deviation and a position deviation. The azimuth deviation is the intersection angle between the target travel path and the center line in the front-rear direction of the vehicle body, and the position deviation is the distance between the target travel path and the reference point of the vehicle body in the cross-cutting direction orthogonal to the target travel path. Therefore, preferably, the deviation allowable range is determined based on the distribution of function values obtained from a bivariate function, where the bivariate function takes the azimuth deviation and the position deviation as variables and is obtained based on experience and experiments. Therefore, the present invention proposes that the deviation allowable range is determined based on the azimuth deviation and the position deviation.

[0012] The turning deviation correction control mode (second deviation correction control mode) is a deviation amount correction driving accompanied by backward movement. Therefore, as a result of driving while working, an inappropriate working trajectory will be caused. Therefore, the present invention proposes non-working driving without field work in the turning deviation correction control mode.

[0013] In order to eliminate only by forward movement the deviation amount exceeding the deviation allowable range generated when transferring from the turning path to the internal path, it is necessary to drive forward for a long distance in the area where the internal path is set. At this time, the working trajectory (in the case where the field working vehicle is a transplanter, it is the seedling transplanting trajectory) that has worked along the adjacent internal path may be disturbed. The driving place for deviation amount correction is preferably the outer peripheral area where the turning path is set. Therefore, it is proposed that in the turning deviation correction control mode, the deviation amount is reduced by backward driving from the internal area to the outer peripheral area towards the outer periphery.

[0014] When backward driving from the internal area to the outer peripheral area is used for deviation amount correction, sometimes the distance required for correction driving cannot be obtained according to the deviation amount. Therefore, in the present invention, it is proposed that in the turning deviation correction control mode, before the backward driving, forward driving is performed for a specified distance. The specified distance of the backward driving used at this time can be calculated based on the deviation amount and the deviation allowable range. Therefore, the present invention also proposes that the specified distance is set to a distance that can make the deviation amount fall within the deviation allowable range through the backward driving.

[0015] In a preferred embodiment of the present invention, the maximum deviation correction amount per unit backward driving distance in the backward driving is set, and the specified distance is obtained based on the maximum deviation correction amount and the deviation amount. With this structure, the specified distance required for correction driving that can make the deviation amount fall within the deviation allowable range can be easily obtained.

[0016] According to the deviation amount, it may be necessary to make the deviation amount fall within the deviation allowable range by slightly moving forward and then moving backward. In such a case, it is efficient when the end point of the backward driving coincides with the start point of the internal path, that is, the start point of the field work. Therefore, the present invention also proposes to execute the turning deviation correction control mode in such a way that the end point of the backward driving becomes the start point of the field work on the internal path. Description of the Drawings

[0017] Figure 1 It is a side view of a transplanter capable of automatic driving.

[0018] Figure 2 It is a schematic diagram for explaining the driving path of the transplanter in the field.

[0019] Figure 3It is a functional block diagram showing the control system of a rice transplanter.

[0020] Figure 4 It is a schematic diagram explaining the deviation amount of the vehicle body.

[0021] Figure 5 It is a flowchart showing an example of a row alignment routine.

[0022] Figure 6 It is a schematic diagram showing the operation of the rice transplanter during row alignment in chronological order.

[0023] Explanation of reference numerals

[0024] 1: Vehicle body; 5: Control unit; 6: On-vehicle terminal; 8: Position measuring unit; 50: Travel control unit; 50A: Automatic travel control unit; 50a: Control mode setting unit; 52: Vehicle body position calculation unit; 53: Travel path setting unit; 55: Vehicle body deviation calculation unit; 65: Travel path generation unit; IA: Inner area; IR: Reciprocating travel path; IRS: Inner path; IRT: Turning path; OA: Outer peripheral area; SH: Boundary line; WSP: Starting point. Detailed implementation manner

[0025] It should be noted that in this specification, unless otherwise specified, "front" refers to the front in the front-rear direction of the vehicle body, and "rear" refers to the rear in the front-rear direction of the vehicle body. That is to say, the front-rear direction of the vehicle body is the travel direction, and the forward direction is Figure 1 shown by the arrow F in Figure 1 and the reverse direction is shown by the arrow B in

[0026] In addition, the left-right direction or the lateral direction refers to the vehicle body cross-cutting direction (vehicle body width direction) orthogonal to the front-rear direction of the vehicle body. "Up" or "down" is the positional relationship in the vertical direction (perpendicular direction) of the vehicle body, indicating the relationship related to the ground clearance.

[0026] Next, a specific implementation manner of the work vehicle of the present invention will be described with reference to the drawings. Figure 1 It is an example of a field work vehicle and is a side view of a transplanter (hereinafter only referred to as a rice transplanter) that automatically travels in the field.

[0027] 〔Overall structure〕

[0028] As Figure 1As shown, the transplanter is a ride-on four-wheel drive vehicle. At the rear of the vehicle body 1, a parallel link mechanism 13 is connected in a manner that can be lifted and swung, and a seedling planting device 3 is assembled to the rear end area of the link mechanism 13 in a manner that can roll. Moreover, a fertilizer application device 4 that is installed from the rear end area of the vehicle body 1 to the seedling planting device 3, a chemical spraying device 30 provided in the rear end area of the seedling planting device 3, etc. are provided. The seedling planting device 3, the fertilizer application device 4, and the chemical spraying device 30 are examples of working devices.

[0029] The vehicle body 1 includes wheels 12, an engine 2 as a power unit, and a hydraulic continuously variable transmission 9 as a main transmission device as mechanisms for traveling. The continuously variable transmission 9 is, for example, an HST (Hydro-Static Transmission: hydrostatic continuously variable transmission), and the driving force (rotation speed) output from the engine 2 is shifted by adjusting the angles of the motor swash plate and the pump swash plate. The wheels 12 include left and right steerable front wheels 12A and left and right non-steerable rear wheels 12B. The engine 2 and the continuously variable transmission 9 are mounted on the front part of the vehicle body 1. The power from the engine 2 is supplied to the front wheels 12A, the rear wheels 12B, the working devices, etc. via the continuously variable transmission 9, etc.

[0030] As an example, the seedling planting device 3 is configured for eight-row planting. The seedling planting device 3 includes a seedling table 21, a planting mechanism 22 for eight rows, etc. It should be noted that the seedling planting device 3 can be changed to two-row planting, four-row planting, six-row planting, etc. forms through clutch control.

[0031] The seedling table 21 is a base for placing cushion-shaped seedlings for eight rows. The seedling table 21 reciprocates in the left-right direction along a fixed stroke corresponding to the left-right width of the cushion-shaped seedlings, and the longitudinal transfer mechanism 23 longitudinally transfers each cushion-shaped seedling on the seedling table 21 toward the lower end of the seedling table 21 at a prescribed interval each time the seedling table 21 reaches the left-right stroke ends. The eight planting mechanisms 22 are rotary type and are arranged in the left-right direction at a fixed interval corresponding to the planting row spacing. And, by the seedling planting clutch being brought into a transmission state, each planting mechanism 22 receives the driving force from the engine 2, cuts a quantity of one seedling (also called a planted seedling) from the lower end of each cushion-shaped seedling placed on the seedling table 21, and plants it into the soil part after land preparation.

[0032] The fertilizer application device 4 includes a hopper 25 that is long in the lateral direction, a feeding mechanism 26, an electric blower 27, a plurality of fertilizer hoses 28, and a furrow opener 29 provided for each row. The hopper 25 stores granular or powdered fertilizer. The feeding mechanism 26 feeds out a quantity of fertilizer for two rows each time from the hopper 25 at a prescribed amount.

[0033] The blower 27 generates a conveying wind that conveys the fertilizer to be conveyed by each conveying mechanism 26 toward the mud surface of the field. The fertilizer application device 4 further includes a clutch mechanism that can switch between a working state in which the fertilizer stored in the hopper 25 is supplied to the field in a specified amount and a non-working state in which the supply is stopped.

[0034] The vehicle body 1 has a driver's cab 14 in the rear side area thereof. The driver's cab 14 includes: a steering wheel 10 for front-wheel steering, a main shift lever 7A for adjusting the vehicle speed by performing a shifting operation of the continuously variable transmission 9, a sub-shift lever 7B for performing a shifting operation of the sub-transmission device, an operation lever 11 for performing operations such as raising and lowering operations and switching of the working state of the seedling planting device 3, an in-vehicle terminal 6 having a function of displaying (notifying) various information and notifying (outputting) it to the operator and accepting the input of various information, and a driver's seat 16 for the operator (driver / worker), etc. Moreover, in front of the driver's cab 14, a pre-seedling storage device 15 for accommodating pre-seedlings is supported by a pre-seedling support frame 17.

[0035] The steering wheel 10 is connected to the front wheels 12A via a steering mechanism (not shown), and the steering angle of the front wheels 12A is adjusted by rotating the steering wheel 10.

[0036] The pre-seedling support frame 17 has an upper and lower two-layer structure composed of a base frame 17a and an arched upper frame 17b provided at the upper end of the base frame 17a. The upper frame 17b is composed of a pair of left and right legs and a cross beam connecting the legs, and is arranged at a height obliquely above the front of the driver's cab 14.

[0037] The positioning unit 8 is assembled to the cross beam of the upper frame 17b. Although not shown in Figure 1 , the remote control receiving unit 9A (refer to Figure 3 ) is assembled to the cross beam of the upper frame 17b side by side with the positioning unit 8 in the horizontal direction. A receiver is assembled below the positioning unit 8. In order to use the positioning unit 8 as a satellite positioning unit, the satellite positioning module 8A (refer to Figure 3 ) provided in the positioning unit 8 adopts a network-type RTK-GNSS (Real-Time Kinematic - Global Navigation Satellite System) positioning method (VRS (Virtual Reference Station) method), so a virtual reference point data receiving unit used in the VRS method is stored in the receiver. As one of the notification device groups 1C, a stacked lamp 19 for notifying driving states such as automatic driving and manual driving is assembled to the upper part of the base frame 17a in the lower area of the receiver.

[0038] This transplanter can perform manual driving, remote control driving, and automatic driving. During manual driving, the driver manually operates operating components such as the steering wheel 10, main transmission lever 7A, sub-transmission lever 7B, and operation lever 11 to perform operation driving. During automatic driving, the transplanter performs operations while driving along a pre-set driving path through automatic control. In addition, automatic driving can be divided into manned automatic driving that requires a driver to board and unmanned automatic driving that does not require a driver to board. During manned automatic driving, while the driver performs part of the operations according to the guidance provided by the transplanter, the transplanter automatically controls other actions that occur during driving and operation. Unmanned automatic driving does not require a driver to board, but a driver can also board during unmanned automatic driving.

[0039] 〔Travel path〕

[0040] Figure 2 The travel path when the transplanter is traveling in the field while performing seedling transplanting operations and fertilization operations is shown. The field is surrounded by a boundary line SH of boundary objects such as dikes, and the boundary line SH is set as the edge of the field. In Figure 2 this example, the field is rectangular, and the edges of the field are composed of a basic edge SH0 (lower edge) and the other three remaining edges. The remaining edges are the left edge SH1, the upper edge SH2, and the right edge SH3. The basic edge SH0 is connected to the farm road, and an entrance / exit for the field operation machine is formed in the end area of the basic edge SH0. Therefore, the basic edge SH0 serves as a supply edge for replenishing seedlings and fertilizers. Therefore, hereinafter, the basic edge SH0 is also referred to as the supply edge, and the same reference numeral SH0 is also given to the supply edge. The transplanter substantially performs operation driving along this travel path with a specified operation width, thereby completing the operations of the entire field (seedling transplanting operations, fertilization operations, chemical spraying operations, etc.).

[0041] The field is divided into an outer peripheral area OA and an inner area IA located inside the outer peripheral area OA. In Figure 2 this example, the transplanter is set with two circumferential travel paths CR for performing circumferential operation driving. The operations for the inner area IA are performed through a reciprocating travel path IR, which is composed of a plurality of inner paths IRS parallel to one of the remaining edges, the left edge SH1, and a turning path IRT connecting the two inner paths IRS. The travel of the reciprocating travel path IR starts at the start point S and ends at the end point G. The inner path IRS is also referred to as a straight path, but it does not necessarily have to be a straight line. For example, it can also be a large arc-shaped line, or it can have a bent portion in the middle. The turning path IRT is substantially a 180° reversing path and is arranged in the outer peripheral area OA.

[0042] For actual generation Figure 2The shown driving paths are the circular driving path CR and the reciprocating driving path IR, and the map coordinates of the accurate field shape and the boundary line SH need to be calculated. For example, the field shape is calculated based on the basic side driving trajectory and the remaining side driving trajectory. Among them, the basic side driving trajectory is obtained by non-operation driving along the basic side SH0, that is, basic side driving, and the remaining side driving trajectory is obtained by operation driving along the remaining side, that is, remaining side driving. In Figure 2 In the example of, the area where the outermost peripheral circular driving path OC and the first circular driving path C1 inside the outermost peripheral circular driving path OC are set is the outer peripheral area OA. Among them, the outermost peripheral circular driving consists of basic side driving and remaining side driving. The number of circular driving paths CR is determined by the necessary space of the turning path IRT of the reciprocating driving path IR, that is, the space required for the turning driving of the transplanter. In Figure 2 In, the number of circular driving paths CR is two. In the case where the circular driving path CR is set to three, in the outer peripheral area OA, in addition to setting the outermost peripheral circular driving path OC and the first circular driving path C1 inside the outermost peripheral circular driving path OC, a second circular driving path is also set inside the first circular driving path C1.

[0043] In actual field operations, when the transplanter enters the field, first, the driver manually steers the transplanter to drive along the basic side SH0 in the outermost peripheral circular driving path OC in a non-operation mode, thereby obtaining the basic side driving trajectory. Next, the driver manually steers the transplanter to drive along the left side SH1, the upper side SH2, and the right side SH3 as the remaining sides on the outermost peripheral circular driving path OC while performing operations, thereby obtaining the remaining side driving trajectory. The field shape is calculated based on the basic side driving trajectory and the remaining side driving trajectory as the driving trajectories in the outermost peripheral circular driving.

[0044] When the field shape is calculated, the number of circular driving paths CR is determined according to the space required for the turning driving in the reciprocating driving path IR or based on the intention of the operation manager. In Figure 2 In the example of, the number of circular driving paths CR other than the outermost peripheral circular driving path OC is one. Therefore, in Figure 2 In, the outer peripheral area OA is the area where two circular driving paths CR are set. The inner area IA is set inside the outer peripheral area OA. When the inner area IA is set, a reciprocating driving path IR for automatically performing reciprocating operation driving from the starting point S to the ending point G in the inner area IA is generated.

[0045] In actual operations, during the reciprocating operation using the reciprocating travel path IR, the vehicle advances to the supply stop position SP, which is a supply point set on the supply side SH0, by means of a supply run, and stops to conduct material supply. In Figure 2 , the supply stop position SP is indicated by a black circle. As Figure 2 shown, during seedling supply, the vehicle proceeds straight from the end of the in-vehicle path IRS during travel and stops at the supply stop position SP in the front docking posture. When the supply is completed, the vehicle advances from the starting point of the in-vehicle path IRS, which is the next travel target (labeled as WSP in Figure 2 ), toward the end of the in-vehicle path IRS via a reverse run using reverse travel.

[0046] 〔Control System〕

[0047] Next, Figure 3 the control system of the transplanter will be described.

[0048] The control system of the transplanter includes a control unit 5 that controls various operations of the transplanter and a vehicle-mounted terminal 6 capable of data exchange with the control unit 5. A travel control system is constructed by the control unit 5 and the vehicle-mounted terminal 6. Signals from a positioning unit 8, a manual operation part sensor group 31, a travel sensor group 32, a work sensor group 33, etc. are input to the control unit 5. Control signals are output from the control unit 5 to the travel machine group 1A and the work machine group 1B.

[0049] The positioning unit 8 includes a satellite positioning module 8A that receives radio waves from satellites of the Global Navigation Satellite System (GNSS) and an inertial measurement module 8B that detects the tilt and acceleration of the three axes of the vehicle body 1. The control unit 5 obtains positioning data for calculating the position and orientation (orientation in the vehicle body front-rear direction) of the vehicle body 1 from the satellite positioning module 8A of the positioning unit 8, and obtains inertial measurement data related to the tilt and acceleration of the three axes of the vehicle body 1 from the inertial measurement module 8B. Here, it is assumed that the positioning data received by the positioning unit 8 also includes inertial measurement data.

[0050] The travel machine group 1A includes a steering machine and a transmission machine. Various machines are controlled based on control signals from the control unit 5 to control the travel of the vehicle body 1.

[0051] The work machine group 1B includes machines that perform lifting adjustment of the seedling planting device 3, adjustment of the seedling taking amount of the planting mechanism 22, adjustment of the fertilizer delivery amount, clutch control for the planting clutch or the material supply row number adjustment clutch, etc.

[0052] The notification device group 1C includes, in addition to the aforementioned stacked lights 19, headlamps for notifying material supply reservations, direction indicators, and speakers, a notification lamp and a notification buzzer. It should be noted that the in-vehicle terminal 6 and the remote controller 90 also function as notification devices.

[0053] The manual operation member sensor group 31 includes sensors, switches, etc. that detect the operation states of various manual operation members. The traveling sensor group 32 includes various sensors that detect states such as steering angle, vehicle speed, and engine speed. The work sensor group 33 includes various sensors that detect the states of the link mechanism 13, the seedling planting device 3, the fertilizer application device 4, etc.

[0054] The control unit 5 includes a traveling control unit 50, a work control unit 51, a vehicle body position calculation unit 52, a traveling path setting unit 53, a notification control unit 54, and a vehicle body deviation calculation unit 55.

[0055] The work control unit 51 automatically controls the work machine group 1B based on a pre-given program during automatic traveling, and controls the work machine group 1B based on the driver's operation during manual traveling.

[0056] The vehicle body position calculation unit 52 calculates the map coordinates (vehicle body position) of the vehicle body 1 based on the satellite positioning data and inertial navigation data sequentially transmitted from the positioning unit 8. These map coordinates can be not only latitude and longitude, but also coordinates in a field coordinate system or a specific coordinate system.

[0057] The traveling path setting unit 53 receives the traveling path generated by the in-vehicle terminal 6 and manages it, and sequentially sets the traveling path as the target traveling path for automatic traveling control.

[0058] The notification control unit 54 receives a notification request from the control system, generates a control signal output to the notification device group 1C, and performs necessary notifications through each notification device.

[0059] The vehicle body deviation calculation unit 55 calculates the deviation amount of the vehicle body 1 relative to the internal path IRS based on the internal path IRS as the target traveling path and the vehicle body position. As Figure 4As shown, the deviation amount of the vehicle body 1 includes an azimuth deviation θ and a position deviation Δd. Among them, the azimuth deviation θ is the intersection angle between the internal path IRS of the target driving path and the center line in the front-rear direction of the vehicle body 1, and the position deviation Δd is the distance between the internal path IRS in the transverse cutting direction orthogonal to the internal path IRS (including the extension line of the internal path IRS) of the target driving path and the reference point of the vehicle body 1. Therefore, the allowable deviation range determined based on the azimuth deviation and the position deviation is determined based on the distribution of the function values obtained from the bivariate function, where the bivariate function takes the azimuth deviation and the position deviation as variables and is obtained based on experience and experiments. This bivariate function may not change continuously or may change in a stepped manner. Preferably, in the determination of whether the deviation amount exceeds the allowable deviation range, a look-up table is used that takes the azimuth deviation and the position deviation as input values and outputs a binary value indicating whether it falls within the allowable deviation range. It should be noted that as the deviation amount of the vehicle body 1, in addition to the above-mentioned azimuth deviation, or on the basis of the azimuth deviation, the inclination of the steering angle of the steering wheel 10 (the steering angle of the front wheel 12A) relative to the neutral state can also be used. In addition, as the azimuth deviation, instead of using the current vehicle body azimuth, the future vehicle body azimuth estimated based on the turn can be used. Moreover, in addition to the above-mentioned position deviation relative to the internal path IRS, or on the basis of such a position deviation, the deviation between the newly set target driving path (an example of a target newly set in a different manner from the internal path IRS for deviation determination during turning) and the reference point of the vehicle body 1 can be used as the position deviation in a different manner from the internal path IRS. Such a newly set target driving path can be preset at a specific timing such as before and after turning or during automatic straight running based on an operator's instruction, and such a target driving path can be set by a path obtained by shifting an existing internal path IRS by a specified amount in the parallel direction. Of course, instead of always calculating the deviation amount of the vehicle body 1 based on both the position deviation and the azimuth deviation, the following automatic driving control can be performed: considering factors such as slipping, errors of the positioning satellite, and the orientation (azimuth) sensor, removing the calculation results of sensors with untrustworthy calculation results, calculating the deviation amount based on only one of the position deviation and the azimuth deviation, and correcting the deviation amount.

[0060] The travel control unit 50 includes an automatic travel control unit 50A, a manual travel control unit 50B, and a control management unit 50C. The travel of this transplanter can be switched between an automatic travel mode for automatic travel, a remote control travel mode for remote control travel, and a manual travel mode for manual travel. Based on the state of an unillustrated travel mode switching operation member and instructions from other functional units of the control unit 5, one of the automatic travel mode (unmanned automatic travel mode, manned automatic travel mode), remote control travel mode, and manual travel mode is selected.

[0061] The manual travel control unit 50B used in the manual travel mode controls the steering machine based on the operation amount of the steering wheel 10, and controls the transmission machine based on the operations of manual operation members such as the main shift lever 7A and the sub-shift lever 7B.

[0062] In the remote control travel mode, the travel control unit 50 controls the steering machine and the transmission machine based on the operation instructions received from the remote controller 90 through the remote control receiving unit 9A.

[0063] The automatic travel control unit 50A used in the automatic travel mode has a control mode setting unit 50a that selectively switches between a first deviation correction control mode (path deviation correction control mode) and a second deviation correction control mode (turn deviation correction control mode). The first deviation correction control mode is an automatic travel mode for normal automatic travel, and realizes the travel of the transplanter along the travel path by automatically steering in a manner that reduces the deviation amount of the vehicle body 1 from the target travel path. Specifically, in the present embodiment, the automatic travel control unit 50A has a path following steering function and a turning automatic steering function, and the automatic travel control unit 50A performs path following control using the first deviation correction control mode so that the vehicle body 1 travels along the target travel path set by the travel path setting unit 53. In the path following control, the vehicle body position calculated by the vehicle body position calculation unit 52 is used to calculate the position deviation of the vehicle body 1 from the target travel path (lateral deviation from the target travel path) and the azimuth deviation of the vehicle body 1 (the deviation angle of the vehicle body azimuth from the azimuth of the target travel path), and steering control (automatic travel control) is performed in a manner that reduces the position deviation and the azimuth deviation.

[0064] The second deviation correction control mode is an automatic travel mode for reducing the deviation amount when the deviation amount calculated by the vehicle body deviation calculation unit 55 exceeds the deviation allowable range when transferring from the turning path IRT to the internal path IRS. As will be described in detail later, the second deviation correction control mode uses reverse to correct the deviation amount, so it is very different from the first deviation correction control mode. Therefore, in the second deviation correction control mode, non-operation travel without accompanying field operations is performed instead of operation travel while performing field operations.

[0065] The in-vehicle terminal 6 is a communication terminal equipped with a touch panel 6A, and the in-vehicle terminal 6 can also be detached from the vehicle body 1 and used as a remote control operation machine for operating the vehicle body 1. The in-vehicle terminal 6 has a graphical interface and has the function of displaying and inputting information through the touch panel 6A; the function of an input / output interface for data of the control unit 5. Of course, in addition to the operations through the touch panel 6A, various operations can also be performed using an operation member (physical device) capable of performing screen operations.

[0066] In this embodiment, the in-vehicle terminal 6 includes a supply side setting unit 61, a field shape calculation unit 62, a travel trajectory management unit 63, a region setting unit 64, and a travel path generation unit 65 as application programs substantially installed in the in-vehicle terminal 6.

[0067] The in-vehicle terminal 6 has a data communication function, and obtains and stores information related to the field through data communication. Information related to the field includes the location of the field, the name of the field, the position of the entrance (exit) of the field, and the locations where supplies such as seedlings and fertilizers can be replenished.

[0068] The supply side setting unit 61 functions as a basic side setting unit, and automatically or manually sets a supply side SH0 as the basic side. The supply side SH0 is a side for replenishment, and usually there are entrances and exits for the agricultural work vehicle formed at both ends or either end of this side.

[0069] In this embodiment, the supply side setting unit 61 can be preset to stop the rice transplanter body at a specified timing and at a specified supply side for material replenishment.

[0070] The travel trajectory management unit 63 operates in association with the vehicle body position calculation unit 52. The travel trajectory management unit 63 generates and stores the travel trajectory of the vehicle body 1 based on the vehicle body position calculated by the vehicle body position calculation unit 52. The field shape calculation unit 62 operates in association with the travel trajectory management unit 63. When the field shape is unknown, the field shape calculation unit 62 calculates the field shape by using, for example, Figure 2 the method described. The region setting unit 64 sets an outer peripheral region OA including a basic side travel trajectory and a remaining side travel trajectory and an inner region IA inside the outer peripheral region OA based on the field shape.

[0071] The travel path generation unit 65 includes: a surrounding travel path generation function that generates a surrounding travel path CR for automatically performing surrounding operation travel in the outer peripheral region OA; and a reciprocating travel path generation function that generates a reciprocating travel path IR (constituted by a turning path IRT and an inner path IRS) for automatically performing reciprocating operation travel in the inner region IA.

[0072] The control unit 5 and the in-vehicle terminal 6 are substantially composed of a computer system. Each functional unit constructed in these computer systems can be realized through the cooperation of the hardware attached to each computer system and the programs installed in each computer system. Of course, in a specific functional unit, its function can be realized only by hardware or only by a program, or can be realized by cooperating with an external application server.

[0073] Next, use Figure 5 andFigure 6 This represents an example of an alignment routine to the internal path IRS when transferring from the turning path IRT to the internal path IRS (commonly referred to as row alignment in field operations). This alignment is characterized in that if the deviation amount is within the allowable deviation range, the normal first deviation correction control mode is used, and if the deviation amount exceeds the allowable deviation range, a special second deviation correction control mode using reverse travel is used.

[0074] First, obtain the vehicle body position calculated by the vehicle body position calculation unit 52 (#11). Calculate the deviation amount between the vehicle body position and the internal path IRS or its extended path to be traveled next by the vehicle body deviation calculation unit 55 (#12). Next, check whether the deviation amount exceeds the allowable deviation range (#13). This situation is shown in Figure 6 #A of

[0075] When the deviation amount falls within the allowable deviation range (the "no" branch of #13), set the first deviation correction control mode (#41), and perform seedling transplanting during normal autonomous driving (automatic steering) (#42).

[0076] When the deviation amount exceeds the allowable deviation range (the "yes" branch of #13), set the second deviation correction control mode (#21). In the second deviation correction control mode, check whether a sufficient reverse distance required for row alignment driving is obtained (#22). When the reverse distance required for row alignment driving is insufficient (the "no" branch of #22), drive forward by a specified distance (#23), and enter #24. This specified distance is calculated as the distance by which the deviation amount can fall within the allowable deviation range through reverse travel. It should be noted that when setting the maximum deviation correction amount that can be corrected per unit reverse travel distance during this reverse travel, the specified distance here is obtained based on this maximum deviation correction amount and the deviation amount. This situation is shown in Figure 6 #B of

[0077] In #24, while performing reverse travel, perform row alignment in such a way that the reference point of the vehicle body 1 is on the extended path of the internal path IRS. This row alignment during reverse travel is shown in Figure 6 #C of Figure 6#D. In this forward movement, it is also preferable to perform automatic steering along the extended path of the internal path IRS or automatic steering targeting the starting point WSP of the internal path IRS. It should be noted that during the control process, the deviation can also be eliminated (row alignment) only by reversing towards the starting point WSP of the internal path IRS.

[0078] When the vehicle body 1 reaches the starting point WSP of the internal path IRS through the forward movement of #26 (the "yes" branch of #27), the first deviation correction control mode is set instead of the second deviation correction control mode (#31), and seedling planting under normal automatic driving is performed (#32).

[0079] In Figure 5 and Figure 6 In the row alignment routine shown, the row alignment in the second deviation correction control mode is performed during the reverse movement towards the outer periphery of the boundary line SH (#24), and this reverse movement proceeds from the internal area IA to the outer peripheral area OA. Instead, the reverse movement for row alignment can also be performed only in the internal area IA or only in the outer peripheral area OA.

[0080] Moreover, in Figure 5 and Figure 6 In the row alignment routine shown, the row alignment completion position is the outer peripheral area OA, and then forward movement (#26) is performed. However, if the row alignment completion position is the internal area IA, the forward movement of #26 is replaced with a reverse movement. In addition, if the row alignment completion position coincides with the starting point WSP of the internal path IRS, #26 is not performed and directly proceeds to #31 and #32 to perform seedling planting under normal automatic driving. Therefore, the second deviation correction control mode can also be executed in such a way that the end point of the reverse movement (row alignment completion position) becomes the starting point WSP, which is the starting point of field operation on the internal path IRS.

[0081] 〔Other Embodiments〕

[0082] (1) In the above embodiments, the field shape is rectangular, but the same driving path is generated for parallelograms and trapezoids. Moreover, the field shape can also be a polygon other than a quadrilateral.

[0083] (2) The functional blocks of the control unit 5 and the in-vehicle terminal 6 shown in Figure 3 can be either subdivided into arbitrary functional blocks or, conversely, integrated into one functional block. In addition, a structure can also be adopted in which arbitrary functional blocks are ECU-ized and connected to each other through the in-vehicle LAN.

[0084] (3) In the above embodiments for row alignment, forward movement is performed at a specified distance ( Figure 5) and correct the deviation amount during the subsequent backward travel ( Figure 5 ) #24), or it may be that steering control for correcting part or all of the deviation amount is also performed during the forward travel.

[0085] (4) In the above-described embodiment, a transplanter was taken as an example for explanation, but the present invention can be applied to direct seeding machines, fertilizer applicators, chemical sprayers, harvesters, tractors, etc.

[0086] It should be noted that the structures disclosed in the above-described embodiments (including other embodiments, the same hereinafter) can be combined and applied with the structures disclosed in other embodiments as long as there is no conflict. In addition, the embodiments disclosed in this specification are illustrative, and the embodiments of the present invention are not limited thereto, and can be appropriately changed without departing from the purpose of the present invention.

[0087] Industrial Applicability

[0088] The present invention can be applied to a field operation vehicle that automatically travels with a travel path set in a field as a control target.

Claims

1. A field work vehicle that travels along a circular travel path and a reciprocating travel path, wherein: The circular driving route is set in an outer peripheral area along the outer periphery of the field, and the reciprocating driving route is composed of an inner route set in an inner area inside the outer peripheral area and a turning route, and is characterized by comprising: A vehicle body position calculation unit, for calculating a vehicle body position; a vehicle body deviation calculation unit that calculates a deviation amount of the vehicle body from the internal path or a target newly set in a manner different from the internal path based on the internal path as a target travel path and the vehicle body position; and The automatic driving control unit has a turning deviation correction control mode for reducing the deviation amount by at least backing up when the deviation amount generated when the turning path is shifted to the inner path exceeds a deviation allowable range.

2. The field work vehicle according to claim 1, characterized in that: In the turning deviation correction control mode, when the deviation amount generated when the vehicle shifts from the turning path to the inner path exceeds the deviation allowable range, the automatic travel control unit reduces the deviation amount by using forward and reverse travel.

3. The field work vehicle according to claim 1, characterized in that: The automatic travel control unit further includes a path deviation correction control mode for reducing the deviation amount during forward travel along the internal path.

4. The field work vehicle according to claim 1, characterized in that: The deviation tolerance range is determined based on the orientation deviation and the position deviation.

5. The field work vehicle according to claim 1, characterized in that: In the turn deviation correction control mode, non-working travel without field work is performed.

6. The field work vehicle according to claim 5, characterized in that: In the turning deviation correction control mode, the deviation amount is reduced by reverse traveling toward the outer periphery from the inner area to the outer peripheral area.

7. The field work vehicle according to claim 6, characterized in that: In the turning deviation correction control mode, the vehicle travels forward for a predetermined distance before the vehicle travels backward.

8. The field work vehicle according to claim 7, characterized in that: The predetermined distance is a distance at which the deviation amount can fall within the deviation allowable range by the reverse running.

9. The field work vehicle according to claim 7, characterized in that: A maximum deviation correction amount per unit reverse travel distance in the reverse travel is set, and the predetermined distance is obtained based on the maximum deviation correction amount and the deviation amount.

10. The field work vehicle according to claim 8, characterized in that: The turn deviation correction control mode is executed so that the end point of the reverse travel becomes the start point of the field work on the internal path.

Images