Field work vehicle

Abstract

To provide a field work vehicle in which a work device can be automatically lowered at a lowering position at an appropriate timing.SOLUTION: A field work vehicle includes: a grounding work device; a positioning unit 8 having a satellite positioning module 8A; a vehicle body position calculation part 53 for calculating a vehicle body position based on the positioning data from the positioning unit 8; a vehicle speed calculation part 54 for calculating a vehicle speed based on the vehicle body position; a vertically moving mechanism which vertically moves the grounding work device between a lowered position at which a grounding work is available and a lifted position at which the grounding work is not available; and a vertical movement control part 51A for controlling the vertically moving mechanism. The vertical movement control part 51A controls a lowering of the grounding work device to the lowered position by the vertically moving mechanism such that the grounding work device reaches the lowered position when the grounding work device reaches the work start position based on the vehicle speed and the work start position of the grounding work.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a field work vehicle that performs field work by repeating work travel, which performs ground work along an internal route set in a field, and turning travel, which connects the internal routes. [Background technology]

[0002] In a field work vehicle such as a rice transplanter, after turning with the ground work implement raised to the raised position, the ground work implement must be lowered from the raised position to the lowered position in order to travel along an internal path to perform field work. For this reason, the work vehicle described in Patent Document 1 is equipped with a drive mechanism that raises and lowers the work implement, which is mounted on the vehicle body so that it can be raised and lowered. This drive mechanism automatically lowers the raised work implement to the ground when the vehicle has traveled a set distance since transitioning from a straight-ahead state to a turning state. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2002-233220 Summary of the Invention [Problem to be solved by the invention]

[0004] In the work vehicle disclosed in Patent Document 1, the timing for lowering the raised working implement to the ground is determined based on the travel distance of the vehicle, but this travel distance is calculated based on the sensor value of a distance sensor that measures the rotation speed of the transmission shaft. However, the travel distance calculated from the rotation speed of the transmission shaft tends to be inaccurate due to wheel slippage, etc., which can result in the working implement not being able to be lowered to the lowered position at the desired timing.

[0005] In view of the above circumstances, an object of the present invention is to provide a farm work vehicle that can automatically lower a ground work implement to a lowered position at an appropriate timing. [Means for solving the problem]

[0006] A field work vehicle according to the present invention performs field work by repeating work travel to perform ground work along an internal route set in the field and turning travel that connects the internal routes, and comprises a ground work device mounted on a vehicle body, a positioning unit having a satellite positioning module, a vehicle body position calculation section that calculates the vehicle body position based on positioning data from the positioning unit, a vehicle speed calculation section that calculates the vehicle speed based on the vehicle body position, a lifting mechanism that raises and lowers the ground work device between a lowered position at which the ground work is possible and an raised position at which the ground work is impossible, and a lifting control section that controls the lifting mechanism, The lifting control unit controls the descent of the ground work device to the lowered position by the lifting mechanism based on at least the vehicle speed and the work start position of the ground work so that the ground work device has reached the lowered position when the ground work device reaches the work start position.

[0007] According to this configuration, the vehicle speed calculated using satellite positioning (GNSS, etc.) can be used to determine the timing for lowering the ground work device to the lowered position, so that the ground work device will reach the lowered position when the field work vehicle (i.e., the ground work device) reaches the work start position, without being adversely affected by slippage of the wheels, etc.

[0008] The work start position for ground work can be determined from the work end position or the swing start position. Therefore, it is also possible to control the lowering of the ground work device to the lowered position by the lifting mechanism based on the work end position or the swing start position. For this reason, in one preferred embodiment of the present invention, the lifting control unit controls the lowering of the ground work device to the lowered position by the lifting mechanism based on the work end position or the swing start position so that the ground work device reaches the work start position. If the travel distance from the end position or the swing start position to the work start position is long or short, it is advisable to adjust the lifting timing taking into account the vehicle speed.

[0009] A field work vehicle travels at a substantially constant speed. Therefore, if an accurate vehicle speed can be obtained, the distance between the vehicle body position and the work start position can be used to determine the accurate time it takes for the field work vehicle at that vehicle body position to reach the work start position. This also accurately determines the timing to start lowering the ground work device so that the ground work device is in the lowered position at the desired vehicle position. For this reason, in one preferred embodiment of the present invention, the lift control unit starts lowering the ground work device to the lowered position based on the vehicle body position, the vehicle speed, and the work start position.

[0010] Furthermore, this farm work vehicle performs ground work by turning (usually a 180° turn) from the internal route (original travel route) that it has traveled on with the ground work implement raised, and then entering the next internal route (next travel route) with the ground work implement lowered. Therefore, the vehicle position on the turning route can be estimated from the vehicle body orientation during turning, and the timing to start lowering the ground work implement can be determined based on this estimated vehicle body position. For this reason, in another preferred embodiment of the present invention, a vehicle body orientation calculation unit is provided that calculates vehicle body orientation, and the lift control unit starts lowering the ground work implement to the lowered position based on the vehicle body orientation and the vehicle speed.

[0011] When a farm work vehicle starts turning, it is necessary to raise the ground work equipment from a lowered position to a raised position. Conventionally, the start of turning is detected based on the turning angle of the steering wheels (front wheels), and this is used to determine the timing to raise the ground work equipment. Alternatively, the vehicle body orientation calculated by the vehicle body orientation calculation unit can also be used to determine the timing to raise the ground work equipment. For this reason, the present invention proposes that the lift control unit start raising the ground work equipment to the raised position based on the vehicle body orientation and the vehicle speed.

[0012] The lifting / lowering speed (lowering speed) of the ground work apparatus by the lifting mechanism can vary depending on various factors, such as the weight of the ground work apparatus and the capacity of the actuator (hydraulic cylinder, electric cylinder, etc.) of the lifting mechanism. Therefore, by taking into account the descent speed of the ground work apparatus by the lifting mechanism, it is possible to more accurately ensure that the ground work apparatus reaches the lowered position when the field work vehicle (i.e., the ground work apparatus) reaches the work start position. For this reason, in a preferred embodiment of the present invention, a lifting / lowering speed management unit is provided that manages the descent speed of the ground work apparatus by the lifting mechanism, and the lifting / lowering control unit adjusts the timing of descent to the lowered position in accordance with the descent speed.

[0013] The quality of the positioning data from the positioning unit varies depending on the reception conditions of satellite radio waves, and if the quality of the positioning data deteriorates, the accuracy of the vehicle position and vehicle speed calculated based on the positioning data also deteriorates. As a result, a problem occurs in that the timing of lowering the ground work implement to the lowered position is not performed as desired. Due to this problem, if a situation occurs in which the ground work implement reaches the lowered position after the field work vehicle (i.e., the ground work implement) has passed the work start position, an unworked area will be created, which must be avoided. For this reason, in a preferred embodiment of the present invention, a positioning status detection unit is provided that detects deterioration of the positioning data from the positioning unit, and the lifting control unit accelerates the descent of the ground work implement to the lowered position when deterioration of the positioning data is detected.

[0014] Clouds, mountains, trees, houses, and other obstacles can obstruct satellite radio waves, reducing the quality of positioning data. Furthermore, vibrations of the vehicle body can cause momentary radio wave interference when the antenna installed on the vehicle body for receiving satellite radio waves shakes. To avoid such problems, it is preferable to average vehicle speeds, which are typically calculated every few milliseconds. Therefore, in a preferred embodiment of the present invention, the vehicle speed calculation unit outputs the average value of multiple vehicle speeds calculated at different times over time as the effective vehicle speed. This average value can be a simple arithmetic average, a weighted average, a moving average, or even a representative value calculated by statistical calculation from multiple values ​​obtained over time. [Brief explanation of the drawings]

[0015] [Figure 1] FIG. 1 is a side view of an automatically traveling rice transplanter. [Figure 2] FIG. 1 is a schematic diagram illustrating the travel path of a rice transplanter in a field. [Figure 3] This is a schematic diagram showing the behavior of the rice transplanter when transitioning from the internal route, which is the original travel route, to the internal route, which is the next travel route, after turning travel. [Figure 4] FIG. 2 is a functional block diagram showing the control system of the rice transplanter. [Figure 5] 10 is a flowchart showing an example of a lowering process of the seedling planting device. DETAILED DESCRIPTION OF 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. In other words, the longitudinal direction of the vehicle body is the traveling direction, with the forward direction indicated by arrow F in FIG. 1 and the backward direction indicated by arrow B in FIG. 1. Furthermore, the left-right direction or lateral direction means the transverse direction of the vehicle body (vehicle body width direction) that is perpendicular to the longitudinal direction of the vehicle body. "Up" or "down" refers to the positional relationship in the vertical direction (perpendicular direction) of the vehicle body, and indicates the relationship regarding the height above the ground.

[0017] Next, one specific embodiment of a field work vehicle according to the present invention will be described with reference to the drawings. Figure 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 Figure 1, the rice transplanter is a ride-on four-wheel drive vehicle. A lifting mechanism 13 of a parallel quadruple link type connected so as to be able to lift and swing is provided at the rear of the vehicle body 1, and a seedling planting device 3 is attached to the rear end region of the lifting mechanism 13 so as to be able to roll. The lifting mechanism 13 is equipped with a hydraulic cylinder 13a as a lifting actuator. Furthermore, the vehicle is equipped with a fertilizer applicator 4 extending from the rear end region of the vehicle body 1 to the seedling planting device 3, and a chemical sprayer 30 provided in the rear end region of the seedling planting device 3. The seedling planting device 3, fertilizer applicator 4, and chemical sprayer 30 are examples of ground work 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 as a main transmission. The continuously variable transmission 9 is, for example, an HST (Hydro-Static Transmission), and changes the driving force (rotation speed) output from the engine 2 by adjusting the angles of a motor swash plate and a pump swash plate. The wheels 12 include left and right front wheels 12A that can be steered, and left and right rear wheels 12B that cannot be steered. The engine 2 and the continuously variable transmission 9 are mounted at the front of the vehicle body 1. Power from the engine 2 is supplied to the front wheels 12A, rear wheels 12B, ground work equipment, etc. via the continuously variable transmission 9 and the like.

[0020] As an example, the seedling planting device 3 is configured for eight rows of planting. The seedling planting device 3 includes a seedling loading table 21, eight rows of planting mechanisms 22, etc. The seedling planting device 3 can be changed to two-row, four-row, six-row, etc. planting by clutch control.

[0021] The seedling tray 21 is a base on which eight rows of mat-shaped seedlings can be placed. The seedling tray 21 moves back and forth in the left-right direction at a constant stroke corresponding to the left-right width of the mat-shaped seedlings, and the vertical feed mechanism 23 vertically feeds each mat-shaped seedling on the seedling tray 21 toward the bottom end of the seedling tray 21 at a predetermined pitch each time the seedling tray 21 reaches the left-right stroke end. The eight planting mechanisms 22 are rotary type and are arranged in the left-right direction at constant intervals corresponding to the spacing between the planting rows. Each planting mechanism 22 receives driving force from the engine 2 when the seedling planting clutch is engaged, and cuts one seedling (also referred to as a planted seedling) from the bottom end of each mat-shaped seedling placed on the seedling tray 21 and plants it in the muddy soil after leveling.

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

[0023] The blower 27 generates a conveying wind that carries the fertilizer dispensed by each dispensing mechanism 26 toward the muddy surface of the field. The fertilizer applicator 4 also has 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 a driver's section 14 in its rear side area. The driver's section 14 is equipped with a steering wheel 10 for steering the front wheels, a main speed change lever 7A that adjusts the vehicle speed by changing the speed of the continuously variable transmission 9, an auxiliary speed change lever 7B that enables speed change operation of the auxiliary speed change lever, an operation operation lever 11 that enables raising and lowering the seedling planting device 3 and switching its operating state, an on-board terminal 6 that displays (announces) various information to the operator and notifies (outputs) it to the operator and has the function of accepting input of various information, and a driver's seat 16 for the operator (driver / worker). Furthermore, in front of the driver's section 14, a spare seedling storage device 15 that stores spare seedlings is supported on 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 by rotating the steering wheel 10.

[0026] The spare seedling support frame 17 has a two-tiered structure consisting of a base frame 17a and an arch-shaped upper frame 17b attached to the upper end of the base frame 17a. The upper frame 17b consists of a pair of left and right legs and a cross beam connecting the legs. The upper frame 17b is positioned diagonally above and in front of the driving unit 14.

[0027] The positioning unit 8 is attached to the cross beam of the upper frame 17b. Although not shown in FIG. 1, a remote control receiver 9A (see FIG. 4) is attached to the cross beam of the upper frame 17b alongside the positioning unit 8. A storage container 18 is attached below the positioning unit 8. In order to use the positioning unit 8 as a satellite positioning unit, a satellite positioning module 8A (see FIG. 4) provided in the positioning unit 8 employs a network-type RTK-GNSS positioning method (VRS method), and therefore a virtual reference point data receiving unit used in the VRS method is stored in the storage container 18. As one of the notification device group 1C, a stacked light 19 that notifies the driving status, such as automatic driving or manual driving, is attached to the top of the base frame 17a in the area below the storage container 18.

[0028] This rice transplanter can be driven manually, remotely, or automatically. In manual driving, the driver manually operates operating devices such as the steering wheel 10, main shift lever 7A, sub-shift lever 7B, and work operation lever 11 to drive the rice transplanter for work. In automatic driving, the rice transplanter performs work while automatically driving along a pre-set driving route. In addition, automatic driving can be performed in two modes: manned automatic driving, which requires a driver on board, and unmanned automatic driving, which does not require a driver on board. In manned automatic driving, the driver performs some operations according to guidance provided by the rice transplanter, while the rice transplanter automatically drives and performs other operations associated with driving and work. In unmanned automatic driving, a driver does not need to be on board, but a driver may be on board during unmanned automatic driving.

[0029] [Route] FIG. 2 shows the travel path of a rice transplanter traveling through a field while planting seedlings and applying fertilizer. This field is surrounded by a boundary line SH, which is a boundary object such as a ridge, and the boundary line SH is set as the field's edge. In the example of FIG. 2, the field is rectangular, and the field's edges consist of a base edge SH0 (bottom edge) and three remaining edges. The remaining edges are a left edge SH1, a top edge SH2, and a right edge SH3. The base edge SH0 is adjacent to a farm road, and an entrance / exit for the field work machine is formed in its end area. For this reason, the base edge SH0 is used as a supply edge for supplying seedlings and fertilizer, and hereinafter the base edge SH0 will also be referred to as the supply edge. The rice transplanter travels substantially along this travel path at a predetermined working width to complete work on the entire field (such as planting seedlings, applying fertilizer, and spraying chemicals).

[0030] The field is divided into an outer peripheral area OA and an inner area IA located inside the outer peripheral area OA. In the example of Figure 2, two circular travel routes CR are set up for the rice transplanter to travel around and work. Work in the inner area IA is carried out using a round-trip travel route IR consisting of multiple inner routes IRS parallel to the left side SH1, one of the remaining edges, and a turning route IRT connecting the two inner routes IRS. Travel on the round-trip travel route IR starts at a start point S and ends at an end point G. The inner route IRS is also called a straight route, but it does not necessarily have to be a straight line; for example, it may be a large arc or may have a bend along the way. The turning route IRT is essentially a 180° turning route and is located in the outer peripheral area OA.

[0031] To actually generate the travel routes shown in Figure 2, i.e., the circular travel route CR and the round-trip travel route IR, it is necessary to calculate the accurate field shape and map coordinates of the boundary line SH. For example, the field shape is calculated based on the basic edge travel trajectory obtained during the basic edge travel, which is a non-work travel along the basic edge SH0, and the remaining edge travel trajectory obtained during the remaining edge travel, which is a work travel along the remaining edge. In the example of Figure 2, the outermost circular travel route OC, consisting of the basic edge travel and the remaining edge travel, and the first circular travel route C1 inside the outermost circular travel route OC are set as the outer periphery area OA. The number of circular travel routes CR is determined by the required space for the turning route IRT of the round-trip travel route IR, i.e., the space required for the rice transplanter to turn. In Figure 2, the number of circular driving routes CR is two, but if the number of circular driving routes CR is set to three, in the outer peripheral area OA, in addition to the outermost circular driving route OC and the first circular driving route C1 inside this outermost circular driving route OC, a second circular driving route is set inside the first circular driving route C1.

[0032] In actual field work, when the rice transplanter enters the field, the driver first manually steers the rice transplanter along the basic side SH0 of the outermost circular travel path OC without performing any work, thereby obtaining a basic side travel trajectory. Next, the driver manually steers the rice transplanter along the remaining sides SH1, SH2, and SH3 of the outermost circular travel path OC while performing work, thereby obtaining a remaining side travel trajectory. The field shape is calculated based on the basic side travel trajectory, which is the travel trajectory during the outermost circular travel, and the remaining side travel trajectory.

[0033] Once the field shape is calculated, the number of circular travel routes CR is determined based on the space required for turning travel on the round-trip travel route IR or based on the intentions 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 circumferential area OA is an area in which two circular travel routes CR are set. The inner area IA is set inside the outer circumferential area OA. Once the inner area IA is set, a round-trip travel route IR is generated for automatic round-trip work travel within this inner area IA from the start point S to the end point G.

[0034] FIG. 3 is a schematic diagram illustrating an example of the general behavior of the rice transplanter when it travels from the internal route IRS (original travel route) along which it has traveled for work (seedling planting) through the turning route IRT, and then enters the internal route IRS (next travel route) along which it will travel for work. The seedling planting operation stops at the end point EP (the work end position) of the internal route IRS, which is the original travel route. Furthermore, for the turning operation, the front wheels 12A are steered to a predetermined steering angle, and the seedling planting device 3 rises to a raised position. The start point of this rise of the seedling planting device 3 is indicated by the symbol UP in FIG. 3. When the rice transplanter approaches the start point SP (the work start position) of the internal route IRS, which is the next travel route, through the turning operation, the front wheels 12A are returned to a neutral angle, and the seedling planting device 3 descends to a lowered position in preparation for seedling planting operation from the start point SP (the work start position) of the internal route IRS. The starting point of the descent of the seedling planting device 3 is indicated by the symbol DP in FIG.

[0035] [Control system] Next, the control system of the rice transplanter will be explained using Figure 4.

[0036] The control system of the rice transplanter includes a control unit 5 that controls various operations of the rice transplanter, and an on-board terminal 6 that can exchange data with the control unit 5. The control unit 5 and the on-board terminal 6 form a driving control system. Signals are input to the control unit 5 from a positioning unit 8, a manual operation tool sensor group 31, a driving sensor group 32, a work sensor group 33, etc. Control signals are output from the control unit 5 to the driving 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 three axes of the vehicle body 1. The control unit 5 obtains positioning data for calculating the position and orientation (forward / backward orientation of the vehicle body) of the vehicle body 1 from the satellite positioning module 8A of the positioning unit 8, and obtains inertial measurement data relating to the inclination 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 the inertial measurement data.

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

[0039] The work equipment group 1B includes a hydraulic cylinder 13a that raises and lowers the seedling planting device 3, an adjustment device for the seedling amount of the planting mechanism 22, an adjustment device for the fertilizer feed amount, and a clutch control device for the planting clutch and the material supply row number adjustment clutch.

[0040] The notification device group 1C includes the aforementioned stacked lights 19, headlights for notifying material replenishment reservations, turn signals, speakers, as well as notification lamps and notification buzzers. 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 operating status of various manual operation tools. The travel sensor group 32 includes various sensors that detect the steering angle, gear position, engine RPM, etc. The work sensor group 33 includes various sensors that detect the status of the lifting mechanism 13, seedling planting device 3, fertilizer applicator 4, etc.

[0042] In this embodiment, the control unit 5 is equipped with a driving control unit 50, an operation control unit 51, a positioning status detection unit 52, a vehicle position calculation unit 53, a vehicle speed calculation unit 54, a vehicle orientation calculation unit 55, a vehicle deviation calculation unit 56, a driving route setting unit 57, a notification control unit 58, and a remote control control unit 59.

[0043] The travel control unit 50 is equipped with an automatic travel control unit 50A and a manual travel control unit 50B. The travel of this rice transplanter can be switched between an automatic travel mode for automatic travel, a remote control travel mode for remotely controlled travel, and a manual travel mode for manual travel. Based on the state of a travel mode switching operating device (not shown) and commands 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.

[0044] The automatic driving control unit 50A used in the automatic driving mode performs steering control so that the vehicle body 1 travels along the target driving route set in the driving route setting unit 57. In this steering control, the vehicle body position calculated by the vehicle body position calculation unit 53 and the vehicle body orientation calculated by the vehicle body orientation calculation unit 55 are used to calculate the position deviation of the vehicle body 1 from the target driving route (lateral deviation from the target driving route) and the orientation deviation of the vehicle body 1 (deviation angle of the vehicle body orientation from the orientation of the target driving route), and steering control (automatic driving control) is performed so that the position deviation and orientation deviation become small.

[0045] The manual driving control unit 50B used in the manual driving mode controls the steering equipment based on the amount of operation of the steering wheel 10, and also controls the transmission equipment based on the operation of manual operating tools such as the main shift lever 7A and the sub-shift lever 7B.

[0046] In the remote control driving mode, based on operation commands from the remote control 90 received by the remote control receiver 9A, the remote control control unit 59 issues commands to the driving control unit 50 and the work control unit 51 to operate the driving equipment group 1A and the work equipment group 1B.

[0047] In automatic driving, the work control unit 51 automatically controls the work equipment group 1B based on a program that has been given to it in advance; in manual driving, the work control unit 51 controls the work equipment group 1B based on the operation of the driver; and in remote control driving, the work control unit 51 controls the work equipment group 1B based on operation commands from the remote control 90.

[0048] In this embodiment, the work control unit 51 includes a lifting control unit 51A and a lifting speed management unit 51B. The lifting control unit 51A controls the movement of the hydraulic cylinder 13a of the lifting mechanism 13 to raise and lower the seedling planting device 3 between an elevated position where seedling planting (ground work) is not possible and a lowered position where seedling planting is possible. The basic control function of the lifting control unit 51A is to lower the seedling planting device 3 to the lowered position based on the vehicle speed and the work start position of the seedling planting work so that the seedling planting device 3 will have reached the lowered position when it reaches the work start position (start point SP of the internal route IRS).

[0049] The following specific functions are given as specific examples of the basic functions of the lift control section 51A described above. (Function A) Starts the lowering of the seedling planting device 3 to the lowering position based on the vehicle body position, vehicle speed, and work start position (starting point SP of the internal route IRS). (Function B) Based on the vehicle direction and vehicle speed, the seedling planting device 3 starts to lower to the ground work device's lowering position, assuming the elapsed time and traveled distance from the work end position (end point EP of the internal route IRS) as prerequisites. (Function C) Adjust the timing of lowering the seedling planting device 3 to the lowered position according to the lowering speed of the seedling planting device 3. (Function D) When the positioning state detection unit 52 detects that the positioning data has deteriorated, the seedling planting device 3 is lowered to the lowered position more quickly. These functions A-4 can be optionally selected and equipped as optional functions.

[0050] Furthermore, the lifting control unit 51A can also determine the timing at which the seedling planting device 3 starts to rise to the raised position after passing the work end position of the internal route IRS (end point EP of the internal route IRS) based on the vehicle orientation and the vehicle speed.

[0051] The lifting speed management unit 51B is a functional unit for realizing the above-mentioned function C, and calculates and manages the lowering speed of the seedling planting device 3 by the hydraulic cylinder 13a of the lifting mechanism 13. Specifically, if the lowering speed is slower than the set speed, the timing at which the seedling planting device 3 starts to lower to the lowered position is advanced.

[0052] The positioning status detection unit 52 detects deterioration in the quality of the positioning data based on the number of captured satellites and the like from the positioning information including the positioning data sent from the positioning unit 8. This detection result is used in function D of the elevation control unit 51A described above.

[0053] The vehicle position calculation unit 53 calculates the map coordinates (vehicle position) of the vehicle 1 based on the satellite positioning data and inertial navigation data successively sent from the positioning unit 8. These map coordinates may be coordinates in not only latitude and longitude but also in a field coordinate system or a specific coordinate system.

[0054] The vehicle speed calculation unit 54 calculates the vehicle speed from the distance between two vehicle positions calculated over time and the elapsed time. In this embodiment, the vehicle speed calculation unit 54 outputs the average value (or representative value) obtained by averaging multiple vehicle speeds calculated over time as the vehicle speed. Note that the section travel time required for a certain travel distance section can be treated equivalently to the vehicle speed, so in the present invention, such section travel time should also be treated equivalently to the vehicle speed in the present invention. In other words, the present invention also includes determining the lowering position of the seedling planting device 3 based on the section travel time.

[0055] The vehicle body direction calculation unit 55 calculates and outputs the vehicle body direction (direction of vehicle body travel direction) based on a direction vector determined from two vehicle body positions calculated over time.

[0056] The vehicle body deviation calculation unit 56 calculates the deviation amount of the vehicle body 1 from the target driving route (for example, the internal route IRS or an extension of the internal route IRS) and the vehicle body position. The deviation amount of the vehicle body 1 includes an orientation deviation, which is the intersection angle between the target driving route and the longitudinal center line of the vehicle body 1 indicated by the vehicle body orientation, and a position deviation, which is the distance between the internal route IRS and a reference point of the vehicle body 1 in the transverse direction perpendicular to the target driving route.

[0057] The driving route setting unit 57 receives and manages the driving routes generated by the in-vehicle terminal 6, and sequentially sets the driving routes that are targets for automatic driving control as target driving routes.

[0058] Upon receiving a notification request from the control system, the notification control unit 58 generates a control signal to be output to the notification device group 1C, and performs the necessary notification through each notification device.

[0059] The in-vehicle terminal 6 is a communication terminal equipped with a touch panel 6A, and can be detached 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 has the function of displaying and inputting information through the touch panel 6A, as well as the function of acting as a data input / output interface for the control unit 5.

[0060] In this embodiment, the vehicle-mounted terminal 6 is equipped with a supply edge setting unit 61, a field shape calculation unit 62, a driving trajectory management unit 63, an area setting unit 64, and a driving route generation unit 65, which are essentially applications installed on the vehicle-mounted terminal 6.

[0061] The on-board terminal 6 has a data communication function, and acquires and stores information about the farm field through data communication. The information about the farm field includes the location of the farm field, the name of the farm field, the location of the entrance (exit) of the farm field, and places that can be used to replenish seedlings and fertilizer.

[0062] The supply edge setting unit 61 sets a supply edge automatically or manually. A supply edge is an edge used for supply, and the basic edge SH0 is usually selected. An entrance / exit for agricultural vehicles is formed at both ends or at either end of the basic edge SH0.

[0063] In this embodiment, the supply side setting unit 61 can set in advance to stop the rice transplanter at a predetermined timing and at a predetermined supply side in order to supply materials.

[0064] The traveling trajectory management unit 63 operates in cooperation with the vehicle body position calculation unit 53. The traveling trajectory management unit 63 generates and stores a traveling trajectory of the vehicle body 1 based on the vehicle body position calculated by the vehicle body position calculation unit 53. The field shape calculation unit 62 operates in cooperation with the traveling trajectory management unit 63. When the field shape is unknown, the field shape calculation unit 62 calculates the field shape using the method described using FIG. 2. The area setting unit 64 sets an outer periphery area OA including the basic side traveling trajectory and the remaining side traveling trajectory, and an inner area IA inside the outer periphery area OA, based on the field shape.

[0065] The travel path generation unit 65 has a circular travel path generation function that generates a circular travel path CR for automatically traveling around the outer peripheral area OA for work, and a round trip travel path generation function that generates a round trip travel path IR (consisting of a turning path IRT and an internal path IRS) for automatically traveling back and forth for work in the internal area IA.

[0066] The control unit 5 and the in-vehicle terminal 6 are essentially configured as computer systems. Each functional unit configured in these computer systems can be realized by the cooperation of hardware associated with each computer system and programs installed in each computer system. Of course, the function of a specific functional unit may be realized only by hardware or programs, or may be realized in cooperation with an external application server.

[0067] Next, an example of the lifting and lowering process of the seedling planting device 3 will be described with reference to Fig. 5. This lifting and lowering process is the lifting and lowering process of the seedling planting device 3 when the rice transplanter turns from the internal route IRS (original travel route) where the seedling planting work has been carried out, and enters the internal route IRS (next travel route) where the next seedling planting work will be carried out.

[0068] During seedling planting operations along the internal route IRS, the vehicle position is acquired (#01), and a check is made to see if the vehicle 1 (more precisely, the seedling planting device 3) has passed the end point EP of this internal route IRS (original travel route) (#02). When the seedling planting device 3 passes the end point EP of this internal route IRS (original travel route) (#02 Yes branch), the seedling planting operation of the seedling planting device 3 is stopped, and the seedling planting device 3 rises from the lowered position to the raised position (#03), and the device begins turning toward the next travel route, which is the next internal route IRS to be traveled (#04). The timing of the seedling planting device 3's ascent is determined by the travel distance and travel time since passing the end point EP, or the steering angle of the steering wheel, a predetermined vehicle orientation, etc.

[0069] When turning travel begins, the position of the start point SP, which is the work start position on the next travel route, is acquired (#05). Next, the vehicle speed is acquired (#06). Once the vehicle speed and work start position are acquired, the timing to start descending the seedling planting device 3 from the raised position to the lowered position is determined (#07). This descent start timing is determined so that when the seedling planting device 3 reaches the work start position (start point SP of the internal route IRS), the seedling planting device 3 will have descended to the lowered position. This determination can be made based on the descent control function of the lifting / lowering control unit 51A and the adopted function from the above-mentioned functions A, B, C, and D.

[0070] When the determined timing for starting descent arrives (#08: Yes branch), the seedling planting device 3 starts to descend from the raised position to the lowered position (#09). When the seedling planting device 3 has finished descending to the lowered position (#10), a check is made to see if the vehicle body 1 (more precisely, the seedling planting device 3) has reached the start point SP of the internal route IRS (next travel route) along which the next seedling planting work will be carried out (#10). When the seedling planting device 3 has reached the start point SP (#11: Yes branch), or just before the seedling planting device 3 reaches the start point SP, the seedling planting operation of the seedling planting device 3 begins (#12).

[0071] 5 does not clearly show the conditions for starting (180° turning steering angle) and stopping (returning to neutral steering angle) turning, but in the case of manual turning, the start and stop are determined by the driver. In the case of automatic turning, turning is started when, for example, the travel distance or travel time since passing the end point EP reaches a predetermined value, and turning is stopped when the vehicle heading nearly matches the heading of the next travel route.

[0072] [Another embodiment] (1) In the above-described embodiment, the turning path IRT is a 180° turn, but it may be a 90° turn or any other turning angle.

[0073] (2) In the above-described embodiment, the lifting control section 51A controlled the lowering of the ground work apparatus 3 by the lifting mechanism 13 to the lowered position based on at least the vehicle speed and the work start position of the ground work so that the ground work apparatus 3 had reached the lowered position when the ground work apparatus 3 reached the work start position. Since this can be determined from the work end position or the swing start position, it is also possible to control the lowering of the ground work apparatus 3 by the lifting mechanism 13 to the lowered position based on the work end position or the swing start position. Therefore, the lifting control section 51A may control the lowering of the ground work apparatus 3 by the lifting mechanism 13 to the lowered position based on the work end position or the swing start position so that the ground work apparatus 3 had reached the work start position.

[0074] (3) The functional blocks constructed in the control unit 5 and the in-vehicle terminal 6 shown in Fig. 4 can be subdivided into any functional blocks, or conversely, can be integrated into one functional block. Also, any functional block can be made into an ECU, and they can be interconnected via an in-vehicle LAN.

[0075] (4) In the above embodiment, a rice transplanter has been described as an example, but the present invention can be applied to field work vehicles such as direct seeding machines, fertilizer applicators, chemical sprayers, harvesters, and tractors.

[0076] The configurations disclosed in the above embodiments (including other embodiments, the same applies below) can be applied in combination with configurations disclosed in other embodiments, as long as no contradiction arises. Furthermore, the embodiments disclosed in this specification are examples, and the embodiments of the present invention are not limited to these, and can be modified as appropriate within the scope that does not deviate from the purpose of the present invention. [Industrial Applicability]

[0077] The present invention is applicable to a field work vehicle that automatically travels along a travel route set in a field as a control target. [Explanation of symbols]

[0078] 1: Body 3: Seedling planting device (ground work device) 5: Control unit 8: Positioning unit 8A: Satellite positioning module 13: Lifting mechanism 13a: Hydraulic cylinder 50: Driving control unit 51: Work control unit 51A: Lift control section 51B: Elevation speed control section 52: Positioning status detection unit 53: Vehicle position calculation unit 54:Vehicle speed calculation section 55: Vehicle direction calculation unit EP: End point (work end position) IR: Round-trip route IRS: Internal Route IRT: Turning Path SP: Start point (work start position)

Claims

1. A field work vehicle that performs field work by repeating work travel that performs ground work along an internal path set in a field and turning travel that connects the internal paths, A ground work device equipped on the vehicle body; a positioning unit having a satellite positioning module; a vehicle body position calculation unit that calculates a vehicle body position based on the positioning data from the positioning unit; a vehicle speed calculation unit that calculates a vehicle speed based on the vehicle body position; a lifting mechanism that raises and lowers the ground work device between a lowered position at which the ground work is possible and an elevated position at which the ground work is impossible; a lifting control unit that controls the lifting mechanism, The lifting control unit controls the lowering of the ground work device by the lifting mechanism to the lowered position based on at least the vehicle speed and the work start position for the ground work so that the ground work device has reached the lowered position when the ground work device reaches the work start position.

2. 2. The field work vehicle according to claim 1, wherein the lifting control unit controls the lifting mechanism to lower the ground work device to the lowered position based on a work end position or a swing start position so that the ground work device reaches the work start position.

3. The farm work vehicle according to claim 1, wherein the lifting control unit starts lowering the ground work implement to the lowered position based on the vehicle body position, the vehicle speed, and the work start position.

4. A vehicle orientation calculation unit is provided to calculate the vehicle orientation, The farm work vehicle according to claim 1, wherein the lifting control unit starts lowering the ground work implement to the lowered position based on the vehicle body orientation and the vehicle speed.

5. The farm work vehicle according to claim 4, wherein the lifting control unit starts raising the ground work implement to the raised position based on the vehicle body orientation and the vehicle speed.

6. a lifting speed control unit that controls the descent speed of the ground work device by the lifting mechanism, The farm work vehicle according to claim 1 , wherein the lifting control unit adjusts the timing of descent to the lowered position in accordance with the descent speed.

7. a positioning state detection unit that detects deterioration of the positioning data of the positioning unit; The farm work vehicle according to claim 1 , wherein the lift control unit accelerates the descent of the ground work implement to the lowered position when deterioration of the positioning data is detected.

8. The field work vehicle according to any one of claims 1 to 7, wherein the vehicle speed calculation unit outputs an average value of a plurality of vehicle speeds calculated at different times over time as the effective vehicle speed.

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