Field work vehicle

Abstract

To provide an automatic field work vehicle which can effectively solve a deviation amount of a vehicle body when entering the next drive path after a turning drive for turnaround.SOLUTION: A field work vehicle travels along: a periphery travel path set on an outer periphery region of the field; and a reciprocate travel path including an inner path IRS set in an inner region on an inner side of the outer peripheral region and a turning path. The field work vehicle includes: a vehicle body position calculating part for calculating a vehicle body position; a vehicle body deviation calculating part for calculating a deviation amount of the vehicle body from the inner path IRS and the target newly set separately from the inner path IRS based on the inner path IRS as a target travel path and the vehicle body position; and an automatic travel control part having a turn-deviation correction control mode for reducing the deviation amount using at least a backward drive when the deviation amount generated during a transition from the turn path to the inner path IRS exceeds the acceptable deviation range.SELECTED DRAWING: Figure 6

Description

Technical Field

[0001] The present invention relates to a field work vehicle that automatically travels with a driving route set in a field as a control target.

Background Art

[0002] Patent Document 1 discloses a rice transplanter including an automatic steering unit that steers a traveling body along a target traveling route based on the position of the own vehicle and the orientation of the traveling body with respect to the target traveling route. When shifting from turning travel by manual steering to straight travel along a target traveling route by automatic steering, the rice transplanter prohibits shifting to automatic steering travel as long as the orientation of the traveling body exceeds a predetermined allowable range.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the rice transplanter according to Patent Document 1, when entering the next linear traveling route through turning travel for direction change, if the orientation of the vehicle body exceeds a predetermined allowable range, it is necessary for the driver to manually steer to correct the posture of the vehicle body. In automatic driving without a driver on board, it is necessary to stop the travel or perform deviation correction travel with a large posture change of the vehicle body along the traveling route while moving forward. When such deviation correction travel is performed while performing the seedling planting work, uneven seedling planting marks are generated. In addition, when the deviation correction travel is performed without the seedling planting work, a seedling missing area is generated.

[0005] In view of the above-described circumstances, an object of the present invention is to provide a field work vehicle capable of automatic driving that can effectively eliminate even a large amount of deviation of the vehicle body when entering the next traveling route through turning travel for direction change.

Means for Solving the Problem

[0006] The field working vehicle according to the present invention travels along a reciprocating travel route including a circumferential travel route set in an outer peripheral region along the outer periphery of the field, an inner route set in an inner region inside the outer peripheral region, and a turning route, and calculates a vehicle body position. A vehicle body position calculation unit, a vehicle body deviation calculation unit that calculates a deviation amount of the vehicle body with respect to the inner route or a target newly provided separately from the inner route from the inner route and the vehicle body position as a target travel route, and when the deviation amount generated when shifting from the turning route to the inner route exceeds the allowable deviation range, an automatic travel control unit having a turning deviation correction control mode that reduces the deviation amount using at least reverse travel.

[0007] According to this configuration, during automatic travel, when shifting from the turning route to the inner route, if the deviation amount with respect to the inner route or a target newly provided separately from the inner route exceeds the allowable deviation range, the deviation amount is reduced using at least reverse travel and enters the inner route which is the work travel route. Therefore, work travel can be performed from the starting point of the inner route. Thus, if the field working vehicle is a rice transplanter, the occurrence of uneven seedling planting marks and seedling-deficient areas can be avoided. Even with other field working vehicles, good field work can be achieved.

[0008] In order to automatically travel the reciprocating travel route including the inner route and the turning route, in the present invention, the automatic travel control unit further has a route deviation correction control mode for reducing the deviation amount during forward travel along the inner route. That is, the automatic travel control unit has two different deviation correction control modes: a first deviation correction control mode which is this route deviation correction control mode, and a second deviation correction control mode which is the above-described turning deviation correction control mode. Thereby, the field working vehicle can automatically travel all of the inner route and the turning route.

[0009] The appropriate posture of the vehicle body (field working vehicle) required to properly perform automatic driving along the target driving route is defined by the azimuth deviation, which is the intersection angle between the target driving route and the center line in the longitudinal direction of the vehicle body, and the position deviation, which is the distance between the target driving route and the reference point of the vehicle body in the transverse direction orthogonal to the target driving route. From this, it is convenient if the deviation tolerance range is determined based on the distribution of function values obtained from an empirical and experimental bivariate function with the azimuth deviation and the position deviation as variables. Therefore, in the present invention, it is proposed that the deviation tolerance range is determined based on the azimuth deviation and the position deviation.

[0010] Since the turning deviation correction control mode (second deviation correction control mode) is a deviation amount correction driving with backward movement, the driving while performing work will result in an inappropriate work trajectory. Therefore, in the present invention, it is proposed that non-work driving without field work is performed in the turning deviation correction control mode.

[0011] In order to eliminate the deviation amount exceeding the deviation tolerance range generated when shifting from the turning route to the internal route only by forward movement, it is necessary to drive forward for a long distance in the area where the internal route is set. At that time, there is a possibility of disturbing the work traces (seedling planting traces in the case of a field working vehicle being a rice transplanter) worked along the adjacent internal route. The driving location for deviation amount correction is preferably the outer peripheral area where the turning route is set. Therefore, in the turning deviation correction control mode, it is proposed to reduce the deviation amount by backward driving from the internal area to the outer peripheral area toward the outer periphery.

[0012] When reverse running from the inner region into the outer peripheral region is used to correct the deviation amount, depending on the deviation amount, there may be a case where the distance required for the correction running cannot be obtained. For this reason, in the present invention, in the turning deviation correction control mode, it is also proposed that forward running is performed by a predetermined distance prior to the reverse running. The predetermined distance of the reverse running used at that time can be calculated based on the deviation amount and the allowable deviation range. Therefore, in the present invention, it is also proposed that the predetermined distance is a distance that allows the deviation amount to fall within the allowable deviation range by the reverse running.

[0013] In a preferred embodiment of the present invention, a maximum deviation correction amount per unit reverse running distance in the reverse running is set, and the predetermined distance is obtained based on the maximum deviation correction amount and the deviation amount. With this configuration, the predetermined distance required for the correction running to bring the deviation amount within the allowable deviation range can be easily obtained.

[0014] Depending on the deviation amount, there is a possibility that the deviation amount may fall within the allowable deviation range by a slight forward movement and subsequent reverse movement. In such a case, it is efficient if the end point of the reverse running coincides with the start point of the inner path, that is, the start point of the field work. For this reason, in the present invention, it is also proposed that the turning deviation correction control mode is executed so that the end point of the reverse running becomes the start point of the field work in the inner path.

Brief Description of the Drawings

[0015]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Best Mode for Carrying Out the Invention

[0016] In this specification, unless otherwise specified, "front" means the front in the longitudinal direction of the vehicle body, and "rear" means the rear in the longitudinal direction of the vehicle body. That is, the longitudinal direction of the vehicle body is the traveling direction, the forward direction is indicated by arrow F in FIG. 1, and the reverse direction is indicated by arrow B in FIG. 1. Also, the left-right direction or the lateral direction means the transverse direction of the vehicle body (the vehicle width direction) perpendicular to the longitudinal direction of the vehicle body. "Upper" or "lower" is the positional relationship in the vertical direction (perpendicular direction) of the vehicle body and indicates the relationship regarding the ground height.

[0017] Next, with reference to the drawings, one specific embodiment of the work vehicle according to the present invention will be described. FIG. 1 is a side view of a transplanter (hereinafter simply referred to as a rice transplanter) that automatically travels in a field, which is an example of a field work vehicle.

[0018] 〔Overall Structure〕 As shown in FIG. 1, the rice transplanter is a four-wheel drive vehicle of the passenger type. At the rear part of the vehicle body 1, a link mechanism 13 of a parallel four-link type that is connected so as to be able to lift and swing is provided, and a seedling planting device 3 that is connected so as to be able to roll is attached to the rear end region of the link mechanism 13. Further, a fertilizer application device 4 installed from the rear end region of the vehicle body 1 to the seedling planting device 3, and a chemical spraying device 30 provided in the rear end region of the seedling planting device 3 and the like are provided. The seedling planting device 3, the fertilizer application device 4, and the chemical spraying device 30 are examples of working devices.

[0019] The vehicle body 1 is equipped with wheels 12 as a mechanism for traveling, an engine 2 as a power unit, and a hydraulic continuously variable transmission 9 which is the main transmission device. The continuously variable transmission 9 is, for example, an HST (Hydro - Static Transmission), and varies the driving force (rotation speed) output from the engine 2 by adjusting the angles of the motor swash plate and the pump swash plate. The wheels 12 include steerable left and right front wheels 12A and non - steerable left and right rear wheels 12B. The engine 2 and the continuously variable transmission 9 are mounted at 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 device, etc. via the continuously variable transmission 9 and the like.

[0020] The seedling planting device 3 is configured in an 8 - row planting format as an example. The seedling planting device 3 includes a seedling placing table 21, planting mechanisms 22 for 8 rows, etc. Note that this seedling planting device 3 can be changed to formats such as 2 - row planting, 4 - row planting, 6 - row planting, etc. by clutch control.

[0021] The seedling placing table 21 is a pedestal for placing mat - shaped seedlings for 8 rows. The seedling placing table 21 reciprocates in the left - right direction with a certain stroke corresponding to the left - right width of the mat - shaped seedlings. The longitudinal feeding mechanism 23 longitudinally feeds each mat - shaped seedling on the seedling placing table 21 at a predetermined pitch toward the lower end of the seedling placing table 21 every time the seedling placing 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 constant interval corresponding to the row spacing for planting. And each planting mechanism 22 has the driving force transmitted from the engine 2 when the seedling - planting clutch is in the transmission state, cuts off a single - plant seedling (also referred to as a planted seedling) from the lower end of each mat - shaped seedling placed on the seedling placing table 21, and plants it in the soil part after soil preparation.

[0022] The fertilizer application device 4 includes a horizontally long hopper 25, a feeding mechanism 26, an electric blower 27, a plurality of fertilizer hoses 28, and furrow openers 29 provided for each row. The hopper 25 stores granular or powdered fertilizer. The feeding mechanism 26 feeds a predetermined amount of fertilizer for two rows from the hopper 25 each time.

[0023] The blower 27 generates a conveying air flow that conveys the fertilizer fed out by each feeding mechanism 26 toward the muddy surface of the field. This fertilizer application device 4 is also equipped with a clutch mechanism that switches between an operating state in which the fertilizer stored in the hopper 25 is supplied to the field in predetermined amounts and a non-operating state in which the supply is stopped.

[0024] The vehicle body 1 is provided with an operation unit 14 in the rear side region thereof. The operation unit 14 includes a steering wheel 10 for front wheel steering, a main shift lever 7A for adjusting the vehicle speed by performing a shift operation of the continuously variable transmission 9, a sub-shift lever 7B enabling a shift operation of the sub-transmission, a work operation lever 11 enabling lifting operations and switching of the operating state of the seedling planting device 3, an in-vehicle terminal 6 having a function of displaying (notifying) various information to notify (output) to the operator and receiving input of various information, and a driver's seat 16 for the operator (driver / worker), etc. Further, in front of the operation unit 14, a spare seedling storage device 15 for storing spare seedlings is supported by a spare seedling support frame 17.

[0025] 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 through the rotation operation of the steering wheel 10.

[0026] The spare seedling support frame 17 has an upper and lower two-stage structure composed of a base frame 17a and an arch-shaped 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 located obliquely upward in front of the operation unit 14.

[0027] The positioning unit 8 is attached to the cross beam of the upper frame 17b. Although not shown in FIG. 1, the remote control receiver 9A (see FIG. 4) is attached to the cross beam of the upper frame 17b side by side with the positioning unit 8. A storage device 18 is attached below the positioning unit 8. In order to use the positioning unit 8 as a satellite positioning unit, since the satellite positioning module 8A (see FIG. 4) provided in the positioning unit 8 adopts the network type RTK-GNSS positioning method (VRS method), a virtual reference point data receiving unit used in the VRS method is stored in the storage device 18. As one of the notification device groups 1C, a stacked lamp 19 for notifying the running state such as automatic running and manual running is attached to the upper part of the base frame 17a in the lower area of the storage device 18.

[0028] This rice transplanter can perform manual driving, remote control driving, and automatic driving. Manual driving is when the driver manually operates operating tools such as the steering wheel 10, main transmission lever 7A, sub-transmission lever 7B, and work operation lever 11 to perform work driving. Automatic driving is when the rice transplanter automatically controls while driving along a preset driving route to perform work. Also, automatic driving can be manned automatic driving that requires the driver to board and unmanned automatic driving that does not require the driver to board. Manned automatic driving is when the rice transplanter automatically controls the operations associated with other driving and work while the driver performs some operations along the guidance provided by the rice transplanter. In unmanned automatic driving, it is not necessary for the driver to board, but the driver may board during unmanned automatic driving.

[0029] 〔Travel Route〕 FIG. 2 shows a traveling route when the rice transplanter travels in the field while performing the seedling planting operation and the fertilizing operation. This field is surrounded by a boundary line SH of boundary objects such as ridges, and the boundary line SH is set as the side of the field. In the example of FIG. 2, the field is rectangular, and the sides of the field consist of a basic side SH0 (lower side) and the other three remaining sides. The remaining sides are the left side SH1, the upper side SH2, and the right side SH3. The basic side SH0 is in contact with the farm road, and an entrance / exit for the field working machine is formed in its end region. Therefore, since the basic side SH0 is used as a supply side for replenishing seedlings and fertilizers, hereinafter, the basic side SH0 is also referred to as the supply side, and the same reference numeral SH0 is given to the supply side. By the rice transplanter traveling along this traveling route substantially at a predetermined working width, the work for the entire field (seedling planting work, fertilizing work, chemical spraying work, etc.) is completed.

[0030] The field is divided into an outer peripheral region OA and an inner region IA located inside the outer peripheral region OA. In the example of FIG. 2, two circular traveling routes CR for the rice transplanter to perform circular working travel are set. The work for the inner region IA is performed by a reciprocating travel route IR consisting of a plurality of inner routes IRS parallel to one of the remaining sides, which is the left side SH1, and a turning route IRT connecting the two inner routes IRS. The travel of the reciprocating travel route IR starts at the starting point S and ends at the ending point G. The inner route IRS is also referred to as a straight travel route, but it does not necessarily have to be a straight line. For example, it may be a large arc-shaped line or may have a bent portion in the middle. The turning route IRT is substantially a 180° direction-changing route and is arranged in the outer peripheral region OA.

[0031] In order to actually generate the travel routes shown in Fig. 2, that is, the circular travel route CR and the reciprocating travel route IR, it is necessary to calculate the accurate field shape and the map coordinates of the boundary line SH. For example, the field shape is calculated based on the basic side travel locus obtained by non-working travel along the basic side SH0, which is the basic side travel, and the remaining side travel locus obtained by working travel along the remaining sides. In the example of Fig. 2, the outer peripheral region OA is the region where the outermost peripheral circular travel route OC composed of the basic side travel and the remaining side travel, and the first circular travel route C1 inside the outermost peripheral circular travel route OC are set. The number of circular travel routes CR is determined by the required space for the turning route IRT of the reciprocating travel route IR, that is, the space required for the turning travel of the rice transplanter. In Fig. 2, the number of circular travel routes CR is two. However, when the number of circular travel routes CR is set to three, in the outer peripheral region OA, in addition to the outermost peripheral circular travel route OC and the first circular travel route C1 inside this outermost peripheral circular travel route OC, a second circular travel route is set inside the first circular travel route C1.

[0032] In actual field work, when the rice transplanter enters the field, first, along the basic side SH0 of the outermost peripheral circular travel route OC, the driver manually steers and drives the rice transplanter without performing work, thereby obtaining the basic side travel locus. Next, along the remaining sides, which are the left side SH1, the upper side SH2, and the right side SH3, of the outermost peripheral circular travel route OC, the driver manually steers and drives the rice transplanter while performing work, thereby obtaining the remaining side travel locus. Based on the basic side travel locus and the remaining side travel locus, which are the travel loci in the outermost peripheral circular travel, the field shape is calculated.

[0033] When the field shape is calculated, the number of circular travel routes CR is determined by the space required for turning travel in the reciprocating travel route IR or based on the intention of the work manager. In the example of FIG. 2, the number of circular travel routes CR excluding the outermost circular travel route OC is one. Therefore, in FIG. 2, the outer peripheral region OA is a region where two circular travel routes CR are set. The inner region IA is set inside the outer peripheral region OA. When the inner region IA is set, a reciprocating travel route IR for automatically reciprocatingly traveling the inner region IA from the start point S to the end point G is generated.

[0034] In actual work, during the reciprocating work travel using the reciprocating travel route IR, it advances to the supply stop position SP which is a supply point set on the supply side SH0 by the material supply travel, stops, and the material supply is performed. In FIG. 2, the supply stop position SP is indicated by a black circle. As shown in FIG. 2, at the time of seedling supply, it goes straight from the end of the internal path IRS during travel and stops at the supply stop position SP in the forward collision posture. When the supply is completed, after going through the reverse travel using reverse, it advances from the start point of the internal path IRS (designated as WSP in FIG. 2) which is the next travel target to the end point of the internal path IRS (designated as WEP in FIG. 2).

[0035] 〔Control system〕 Next, the control system of the rice transplanter will be described with reference to FIG. 3.

[0036] The control system of the rice transplanter includes a control unit 5 that controls various operations of the rice transplanter and an in-vehicle terminal 6 that can exchange data with the control unit 5. A travel control system is constructed by the control unit 5 and the in-vehicle terminal 6. Signals from a positioning unit 8, a manual operation tool 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 equipment group 1A and the work equipment group 1B.

[0037] 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 inclination and acceleration of the vehicle body 1 in three axes. The control unit 5 acquires positioning data for calculating the position and orientation (orientation in the longitudinal direction of the vehicle body) of the vehicle body 1 from the satellite positioning module 8A of the positioning unit 8, and acquires inertial measurement data regarding the inclination and acceleration of the vehicle body 1 in three axes 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.

[0038] The traveling device group 1A includes a steering device and a transmission device. Based on the control signal from the control unit 5, various devices are controlled and the traveling of the vehicle body 1 is controlled.

[0039] The working device group 1B includes devices that perform operations such as raising and lowering adjustment of the seedling planting device 3, adjustment of the seedling take-up amount of the planting mechanism 22, adjustment of the fertilizer delivery amount, clutch control for the planting clutch and the material supply number adjustment clutch, and the like.

[0040] The notification device group 1C includes the aforementioned stacked lamp 19, a headlight, a direction indicator, and a speaker for the purpose of notifying a material supply reservation, and also includes a notification lamp and a notification buzzer. Note that the in-vehicle terminal 6 and the remote control 90 also function as notification devices.

[0041] The manual operation tool sensor group 31 includes sensors and switches that detect the operation states of various manual operation tools. The traveling sensor group 32 includes various sensors that detect states such as the steering angle, vehicle speed, and engine speed. The working 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, and the like.

[0042] The control unit 5 is provided with a traveling control unit 50, a working control unit 51, a vehicle body position calculation unit 52, a traveling route setting unit 53, a notification control unit 54, and a vehicle body deviation calculation unit 55.

[0043] In automatic driving, the operation control unit 51 automatically controls the working equipment group 1B based on a pre-given program, and in manual driving, it controls the working equipment group 1B based on the driver's operation.

[0044] 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 sent from the positioning unit 8. These map coordinates may be not only latitude and longitude but also coordinates in a field coordinate system or a specific coordinate system.

[0045] The travel route setting unit 53 receives and manages the travel route generated by the in-vehicle terminal 6, and sequentially sets the target travel route for automatic driving control as the target travel route.

[0046] The notification control unit 54 receives a notification request from the control system, generates a control signal to be output to the notification device group 1C, and performs necessary notifications through each notification device.

[0047] The vehicle body deviation calculation unit 55 calculates the deviation amount of the vehicle body 1 with respect to the internal route IRS as the target travel route from the internal route IRS as the target travel route and the vehicle body position. As shown in FIG. 4, the deviation amount of the vehicle body 1 is the azimuth deviation: θ, which is the intersection angle between the internal route IRS as the target travel route and the longitudinal center line of the vehicle body 1, and the position deviation: Δd, which is the distance between the internal route IRS in the transverse direction orthogonal to the internal route IRS (including the extension line of the internal route IRS) 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 an empirical and experimental two-variable function with the azimuth deviation and the position deviation as variables. This two-variable function does not have to change continuously and may change stepwise. For the determination of whether the deviation amount exceeds the allowable deviation range, it is convenient to use a look-up table with the azimuth deviation and the position deviation as input values and a binary value indicating whether it is within the allowable deviation range as the output value. In addition, as the deviation amount of the vehicle body 1, in addition to or in addition to the above-described azimuth deviation, the inclination of the steering angle of the steering wheel 10 (the steering angle of the front wheel 12A) from the neutral state may be used. Further, as the azimuth deviation, instead of using the current vehicle body azimuth, a future vehicle body azimuth estimated by turning may be used. Furthermore, in addition to or in addition to the position deviation with respect to the internal route IRS as described above, a deviation between a target travel route newly set for deviation determination during turning (an example of a target newly provided separately from the internal route IRS) and the reference point of the vehicle body 1 may be used as the position deviation. Such a newly set target travel route can be set in advance at a specific timing such as an operator's instruction before and after turning or during automatic straight travel, and such a target travel route can be set by a route obtained by shifting the existing internal route IRS by a predetermined amount in the parallel direction. Of course, the deviation amount of the vehicle body 1 is not always calculated by both the position deviation and the azimuth deviation, but in consideration of errors in slip, positioning satellites, direction (azimuth) sensors, etc., except for the calculation results by sensors with unreliable calculation results, the deviation amount is calculated by only one of the position deviation and the azimuth deviation, and automatic driving control for correcting the deviation amount is also possible.

[0048] The traveling control unit 50 is provided with an automatic traveling control unit 50A, a manual traveling control unit 50B, and a control management unit 50C. The traveling of this rice transplanter can be switched between an automatic traveling mode for performing automatic traveling, a remote control traveling mode for performing remote control traveling, and a manual traveling mode for performing manual traveling. Based on the state of a traveling mode switching operation tool (not shown) and commands from other functional units of the control unit 5, any one of the automatic traveling mode (unmanned automatic traveling mode, manned automatic traveling mode), the remote control traveling mode, and the manual traveling mode is selected.

[0049] The manual traveling control unit 50B used in the manual traveling mode controls the steering device based on the operation amount of the steering wheel 10, and controls the transmission device based on the operations of manual operation tools such as the main transmission lever 7A and the sub-transmission lever 7B.

[0050] In the remote control traveling mode, the traveling control unit 50 controls the steering device and the transmission device based on the operation commands from the remote control 90 received by the remote control receiving unit 9A.

[0051] The automatic driving control unit 50A used in the automatic driving 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 driving mode used for normal automatic driving. By automatically steering to reduce the deviation amount of the vehicle body 1 with respect to the target driving route, the traveling of the rice transplanter along the driving route is realized. Specifically, in this embodiment, the automatic driving control unit 50A has a path following steering function and a turning automatic steering function. The automatic driving control unit 50A performs path following control using the first deviation correction control mode so that the vehicle body 1 travels along the target driving route set in the driving route setting unit 53. In the path following control, using the vehicle body position calculated by the vehicle body position calculation unit 52, the position deviation of the vehicle body 1 with respect to the target driving route (lateral deviation with respect to the target driving route) and the azimuth deviation of the vehicle body 1 (deviation angle of the vehicle body azimuth with respect to the azimuth of the target driving route) are calculated, and steering control (automatic driving control) is performed so that this position deviation and azimuth deviation become small.

[0052] The second deviation correction control mode is an automatic driving mode used to reduce the deviation amount when the deviation amount calculated by the vehicle body deviation calculation unit 55 exceeds the deviation allowable range during the transition from the turning route IRT to the internal route IRS. As will be described in detail later, the second deviation correction control mode is quite different from the first deviation correction control mode because it uses reverse travel for correcting the deviation amount. Therefore, in the second deviation correction control mode, the work travel while performing field work is not performed, and the non-work travel without field work is performed.

[0053] The in-vehicle terminal 6 is a communication terminal equipped with a touch panel 6A, and can be removed from the vehicle body 1 and used as a remote control device for operating the vehicle body 1. The in-vehicle terminal 6 has a graphical interface and functions for displaying and inputting information through the touch panel 6A, and functions as an input / output interface for data to the control unit 5. Of course, in addition to the operation through the touch panel 6A, various operations may be performed using an operating tool (physical device) capable of performing screen operations.

[0054] In this embodiment, the in-vehicle terminal 6 is provided with a replenishment side setting unit 61, a field shape calculation unit 62, a travel locus management unit 63, a region setting unit 64, and a travel route generation unit 65, substantially as applications installed in the in-vehicle terminal 6.

[0055] The in-vehicle terminal 6 has a data communication function, and acquires and stores information about the field through data communication. The information about 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 seedlings and fertilizers can be replenished.

[0056] The replenishment side setting unit 61 functions as a basic side setting unit and automatically or through a manual operation, sets a replenishment side SH0 which is a basic side. The replenishment side SH0 is a side used for replenishment, and usually, an entrance / exit of the agricultural work vehicle is formed at both ends or one end of the side.

[0057] In this embodiment, the replenishment side setting unit 61 can preset to stop the rice transplanter body at a predetermined timing and at a predetermined replenishment side for material replenishment.

[0058] The travel locus management unit 63 operates in conjunction with the vehicle body position calculation unit 52. The travel locus management unit 63 generates and stores the travel locus 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 conjunction with the travel locus management unit 63. When the field shape is unknown, the field shape calculation unit 62 calculates the field shape by the method described with reference to FIG. 2. The region setting unit 64 sets an outer peripheral region OA including a basic side travel locus and a remaining side travel locus, and an inner region IA inside the outer peripheral region OA based on the field shape.

[0059] The travel route generation unit 65 includes a circular travel route generation function for generating a circular travel route CR for automatically traveling around the outer peripheral region OA, and a reciprocating travel route generation function for generating a reciprocating travel route IR (consisting of a turning route IRT and an internal route IRS) for automatically traveling back and forth in the internal region IA.

[0060] The control unit 5 and the in-vehicle terminal 6 are substantially configured by a computer system. Each functional unit constructed by these computer systems can be realized by the cooperation of the hardware associated with each computer system and the program installed in each computer system. Of course, in a specific functional unit, the function may be realized only by hardware, only by a program, or by cooperation with an external application server.

[0061] Next, with reference to FIGS. 5 and 6, an example of an alignment routine (generally called row alignment in field work) to the internal route IRS executed when shifting from the turning route IRT to the internal route IRS is shown. The feature of this alignment is that if the deviation amount is within the deviation allowable range, the normal first deviation correction control mode is used, and if the deviation amount exceeds the deviation allowable range, a special second deviation correction control mode using reverse travel is used.

[0062] First, the vehicle body position calculated by the vehicle body position calculation unit 52 is acquired (#11). The deviation amount of the vehicle body position from the internal route IRS to be traveled next or its extended route is calculated by the vehicle body deviation calculation unit 55 (#12). Next, it is checked whether the deviation amount exceeds the deviation allowable range (#13). This situation is shown at #A in FIG. 6.

[0063] When the deviation amount is within the deviation allowable range (#13 No branch), the first deviation correction control mode is set (#41), and seedling planting in normal automatic travel (automatic steering) is performed (#42).

[0064] When the deviation amount exceeds the deviation tolerance range (#13 Yes branch), the second deviation correction control mode is set (#21). In the second deviation correction control mode, it is checked whether there is enough reverse distance to perform alignment driving (#22). If there is not enough reverse distance to perform alignment driving (#22 No branch), the vehicle moves forward by a predetermined distance (#23) and proceeds to #24. This predetermined distance is calculated as the distance by which the deviation amount can enter the deviation tolerance range by reverse driving. If the maximum deviation correction amount that can be corrected per unit reverse driving distance in this reverse driving is set, the predetermined distance here is obtained based on the maximum deviation correction amount and the deviation amount. This situation is shown in #B of FIG. 6. If there is enough reverse distance to perform alignment driving (#22 Yes branch), it proceeds directly to #24.

[0065] At #24, while reversing, alignment is performed so that the reference point of the vehicle body 1 rides on the extended path of the internal path IRS. This alignment during reverse is shown in #C of FIG. 6. If this alignment during reverse is completed (#25 Yes branch), the vehicle moves forward toward the starting point (seedling planting start point) WSP of the internal path IRS, which is the driving target. This forward movement is shown in #D of FIG. 6. Also in this forward movement, it is preferable to perform automatic steering along the extended path of the internal path IRS or automatic steering with the starting point WSP of the internal path IRS as the target point. Note that in this control process, the deviation amount may be eliminated (aligned) only by reversing toward the starting point WSP of the internal path IRS.

[0066] When the vehicle body 1 reaches the starting point WSP of the internal path IRS by the forward movement of #26 (#27 Yes branch), the first deviation correction control mode is set instead of the second deviation correction control mode (#31), and seedling planting in normal automatic driving is performed (#32).

[0067] In the alignment routine shown in FIGS. 5 and 6, the alignment in the second deviation correction control mode is performed by the reverse travel (#24) toward the outer periphery which is the boundary line SH, and this reverse travel is performed from the inner region IA to the outer peripheral region OA. Instead of this, the reverse travel for alignment may be performed only in the inner region IA or only in the outer peripheral region OA.

[0068] Furthermore, in the alignment routine shown in FIGS. 5 and 6, assuming that the alignment completion position is the outer peripheral region OA, the forward travel (#26) is performed thereafter. However, if the alignment completion position is the inner region IA, the forward travel of #26 is replaced with the reverse travel. Also, if the alignment completion position coincides with the starting point WSP of the inner path IRS, #26 is not performed and instead, it proceeds directly to #31 and #32, and the seedling planting in the normal automatic travel is performed. For this reason, the second deviation correction control mode may be executed so that the end point of the reverse travel (alignment completion position) becomes the starting point WSP which is the starting point of the field work in the inner path IRS.

[0069] 〔Alternative Embodiment〕 (1) In the above-described embodiment, the field shape was rectangular, but the same travel path is generated even for a parallelogram or a trapezoid. Furthermore, the field shape may be a polygon other than a quadrilateral.

[0070] (2) The functional blocks constructed in the control unit 5 and the in-vehicle terminal 6 shown in FIG. 3 can be subdivided into arbitrary functional blocks, or conversely, can be integrated into one functional block. Also, a configuration may be adopted in which arbitrary functional blocks are made into ECUs and they are interconnected by an in-vehicle LAN.

[0071] (3) In the above-described embodiment for alignment, the forward travel ( #23 in FIG. 5) was performed by a predetermined distance, and the deviation amount was corrected in the subsequent reverse travel ( #24 in FIG. 5). However, in the forward travel as well, the steering control for correcting part or all of the deviation amount may be performed.

[0072] (4) In the above embodiment, the rice transplanter was taken as an example for explanation. However, the present invention can be applied to direct seeding machines, fertilizer applicators, chemical sprayers, harvesters, tractors, and the like.

[0073] In addition, the configurations disclosed in the above embodiments (including other embodiments, the same applies hereinafter) can be applied in combination with the configurations disclosed in other embodiments as long as there is no contradiction. Also, the embodiments disclosed in this specification are examples, and the embodiments of the present invention are not limited thereto, and can be appropriately modified within the scope not departing from the object of the present invention.

Industrial Applicability

[0074] The present invention is applicable to a field work vehicle that automatically travels with a driving route set in a field as a control target.

Explanation of Signs

[0075] 1: Vehicle body 5: Control unit 6: Vehicle-mounted terminal 8: Positioning unit 50: Travel control unit 50A: Automatic travel control unit 50a: Control mode setting unit 52: Vehicle body position calculation unit 53: Travel route setting unit 55: Vehicle body deviation calculation unit 65: Travel route generation unit IA: Internal area IR: Reciprocating travel route IRS: Internal route IRT: Turning route OA: Outer peripheral area SH: Boundary line WSP: Starting point

Claims

1. A field working vehicle that travels along a reciprocating travel route composed of a circumferential travel route set in an outer peripheral region along the outer periphery of a field, an inner path set in an inner region inside the outer peripheral region, and a turning path, 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 with respect to a target newly provided separately from the inner path or the inner path from the inner path as the target travel route and the vehicle body position, an automatic travel control unit having a turning deviation correction control mode for reducing the deviation amount using at least reverse travel when the deviation amount generated at the time of shifting from the turning path to the inner path exceeds the deviation allowable range, A field working vehicle comprising:

2. The automatic travel control unit reduces the deviation amount using forward and reverse travel when the deviation amount generated at the time of shifting from the turning path to the inner path exceeds the deviation allowable range in the turning deviation correction control mode. The field working vehicle according to claim 1.

3. The automatic travel control unit further has a path deviation correction control mode for reducing the deviation amount during forward travel along the inner path. The field working vehicle according to claim 1.

4. The deviation allowable range is determined based on an azimuth deviation and a position deviation. The field working vehicle according to claim 1.

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

6. In the turning deviation correction control mode, the deviation amount is reduced by reverse travel from the inner region toward the outer periphery up to the outer peripheral region. The field working vehicle according to claim 5.

7. In the turning deviation correction control mode, prior to the reverse travel, forward travel is performed for a predetermined distance. The field working vehicle according to claim 6.

8. The predetermined distance is a distance at which the deviation amount can enter the deviation allowable range by the reverse travel. The field working vehicle according to claim 7.

9. The 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. The field working vehicle according to claim 7.

10. The turning deviation correction control mode is executed such that the end point of the reverse travel becomes the field work start point on the inner path. The field working vehicle according to claim 8.

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