Work vehicle

Abstract

To provide a working vehicle capable of improving working accuracy by preventing a situation in which the working accuracy is reduced due to unstable automatic operation and meandering.SOLUTION: A correction amount operation part mounted on a work vehicle and used for setting a correction amount of automatic steering based on positioning, the correction amount operation part comprising: an operation member configured to be operated in two directions of left and right from a neutral position, the operation member being configured to be selectively operated to a right position, a right end position, a left position, and a left end position; and a biasing mechanism configured to apply a biasing force in a direction of pushing back the operation member to a neutral side when the operation member is operated to the right end position or the left end position.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a work vehicle that performs agricultural work while automatically driving in a field. [Background technology]

[0002] Conventionally, as shown in Patent Documents 1 and 2 below, for example, work vehicles are known that use position information obtained from a satellite-based positioning device to perform agricultural work (hereinafter simply referred to as work) while driving automatically in a field. This type of automatically driven work vehicle can switch between manual and automatic driving, and when in automatic driving mode, the deviation between the vehicle's current position and a planned driving line is calculated based on the acquired position information so that the vehicle travels along a pre-designed planned driving line, and a steering member (such as a steering wheel) is automatically steered in a direction that eliminates the calculated deviation.

[0003] Furthermore, Patent Document 3 discloses a work vehicle that, when an error occurs in the positioning of a positioning device, allows the driver to operate a correction switch that corrects the vehicle's position measured by the positioning device, thereby eliminating the deviation (also called the difference) between the vehicle's position and the planned traveling line. For example, if the vehicle's position detected by the positioning device deviates to the right due to some factor, the vehicle will travel on the left side of the planned traveling line, but according to this technology, the driver, who recognizes that the vehicle has deviated to the left of the planned traveling line, can operate a correction switch and correct the vehicle's position measured by the positioning device to the right, thereby returning the vehicle to the planned traveling line. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2019-187351 [Patent Document 2] Patent Publication No. 2021-069291 [Patent Document 3] Japanese Patent Publication No. 2020-06872 Summary of the Invention [Problem to be solved by the invention]

[0005] However, with conventional work vehicles such as those described in Patent Document 3, the operation of the control switches to correct the misalignment between the intended travel line and the vehicle's position was complicated, which easily led to confusion for the worker. In addition, it was difficult to fine-tune the vehicle's position, which resulted in a problem of reduced work speed.

[0006] Therefore, the present invention aims to solve such problems by providing a work vehicle that allows easy operation of an operating switch to eliminate any discrepancy between the intended travel line and the vehicle's position, and also makes it easy to fine-tune the vehicle's position. [Means for solving the problem]

[0007] In order to achieve the above object, the first invention is: A correction amount operation unit mounted on a work vehicle and used to set a correction amount for automatic steering based on positioning, An operating member is provided which can be operated in two directions, left and right, from a neutral position, and the operating member can be selectively operated to a right position, a rightmost position, a left position, and a leftmost position, The present invention provides a work vehicle comprising a biasing mechanism that applies a biasing force in a direction to push the operating member back toward the neutral side when the operating member is operated to the rightmost position or the leftmost position.

[0008] According to the first invention, by operating the operating member in two directions, it is possible to easily perform operations to eliminate any discrepancy between the intended travel line and the vehicle's position.In addition, when the operating member is operated to the right of the right position or to the left of the left position, a biasing force acts in the pushing back direction, making it easy to fine-tune the position of the vehicle.

[0009] The second invention has the same configuration as the first invention, but also: A correction amount control method for performing automatic steering based on a traveling vehicle body position detected by a positioning device, comprising: Neutral mode, which performs automatic steering relative to a reference position; right shift mode, which shifts the vehicle body to the right by correcting the left; left shift mode, which shifts the vehicle body to the left by correcting the right; a right-neutral transition mode for transitioning from the right shift mode to neutral, and a left-neutral transition mode for transitioning from the left shift mode to neutral; When the correction amount operation unit is operated to an end position, the correction amount is increased at a constant speed, while in the neutral transition mode the correction amount is decreased at a speed slower than the increasing speed to gradually return to neutral.

[0010] According to the second invention, in addition to the effect of the first invention, by differentiating the rate of increase and rate of decrease of the correction amount, it is possible to achieve both responsiveness during line shifting and stability during neutral return.

[0011] The third invention, in addition to the configuration of the second invention, A program for executing correction amount control for a work vehicle, The correction amount at the time of transition from the right / left shift mode to each neutral transition mode is memorized, The stored value is set and reproduced when transitioning from the neutral mode to the right / left shift mode again.

[0012] According to the third aspect of the invention, in addition to the effect of the second aspect of the invention, the value of the correction amount can be quickly reset by utilizing the history of the previous shift, thereby improving work efficiency. [Effects of the Invention]

[0013] According to the present invention, a work vehicle can be provided that allows easy operation of an operating unit to eliminate any discrepancy between the intended travel line and the position of the vehicle, and also makes it easy to fine-tune the position of the vehicle. [Brief explanation of the drawings]

[0014] [Figure 1]FIG. 1 is a left side view of a work vehicle according to an embodiment of the present invention. [Figure 2] Figure 2 is an explanatory diagram of the operating devices located in front of the cockpit. [Figure 3] FIG. 3(a) is a schematic plan view of the correction amount operation unit, FIG. 3(b) is a schematic side view as seen from the cockpit side, and FIG. 3(c) is a schematic plan view explaining the operation position of the correction amount operation unit. [Figure 4] FIG. 4 is a block diagram showing the configuration of the control device and its surroundings in the work vehicle. [Figure 5] FIG. 5 is an explanatory diagram relating to automatic driving of a work vehicle. [Figure 6] 6(a) to 6(c) are explanatory diagrams relating to correction of the amount of deviation of the work vehicle 1. FIG. [Figure 7] FIG. 7 is an explanatory diagram showing the correspondence between the operation position of the correction amount operation unit and the processing executed by the control device. [Figure 8] FIG. 8 is a state transition diagram showing the relationship between the operation position of the correction amount operation unit and the mode and function executed depending on the operation position. [Figure 9] FIG. 9 is a table showing the relationship between each mode and function in FIG. 8 and the operation position of the correction amount operation unit. [Figure 10] 10(a) and 10(b) are schematic front views of an operation panel provided on a control section of a work vehicle according to another embodiment. [Figure 11] FIG. 11 is an explanatory diagram relating to the design of a work vehicle according to another embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0015] A preferred embodiment of the present invention will be described below with reference to the accompanying drawings. In the following description, unless otherwise specified, the forward direction of the work vehicle 1 (the direction from the operator's seat 8 to the steering wheel 9, which will be described later) is referred to as the front, the opposite direction is referred to as the rear, and the right side when facing forward is referred to as the right, and the left side is referred to as the left. The work vehicle 1 (or the traveling vehicle body 2) may also be referred to simply as the machine body.

[0016] <1. Basic configuration of work vehicle> First, the basic configuration of a work vehicle 1 according to the embodiment will be described with reference to Figure 1. Figure 1 is a left side view of the work vehicle 1 according to the embodiment. Note that the following description will be given taking a tractor as an example of the work vehicle 1. Therefore, the work vehicle 1 will be mainly referred to as the tractor 1 below.

[0017] The tractor 1, which is a work vehicle, is an agricultural tractor that travels by itself to perform work in a field, etc. The tractor 1 not only performs predetermined work while a driver (also called an operator) rides on it and travels through the field, but also performs predetermined work while automatically driving through the field by controlling each part using a control system centered on a control device C (see Figure 4), which will be described later, that is disposed at an appropriate position on the vehicle body.

[0018] As shown in Fig. 1, the tractor 1 includes a traveling body 2 and a work implement W. The traveling body 2 includes a body frame 3, front wheels 4, rear wheels 5, a bonnet 6, an engine E, a control unit 7, and a transmission case 10. The body frame 3 and the transmission case 10 form the main frame of the traveling body 2.

[0019] The front wheels 4 are a pair of left and right wheels, and are primarily used for steering (steered wheels). The rear wheels 5 are a pair of left and right wheels, and are primarily used for driving (drive wheels). The tractor 1 may be configured to be switchable between two-wheel drive (2WD) in which the rear wheels 5 are driven, and four-wheel drive (4WD) in which both the front wheels 4 and the rear wheels 5 are driven. In this case, both the front wheels 4 and the rear wheels 5 are drive wheels. The traveling body 2 may be equipped with a crawler device instead of wheels (front wheels 4 and rear wheels 5). In this case, the traveling crawler is the drive wheel.

[0020] The hood 6 is provided at the front of the traveling vehicle body 2 so as to be able to be opened and closed freely. The hood 6 can be rotated (opened and closed) in the vertical direction with the rear part as the rotation center. When closed, the hood 6 covers the engine E mounted on the vehicle body frame 3. The engine E is the driving source of the tractor 1 and is a heat engine such as a diesel engine or a gasoline engine.

[0021] The control unit 7 receives operations from the worker and functions to steer the work vehicle 1, and a control room is defined inside a cabin box 7a that covers the top of the traveling body 2, and the control room is configured to be equipped with various operating members that receive operations from the worker, such as a driver's seat 8 where the worker sits and a steering wheel 9. The steering wheel 9 is a member that steers the front wheels 4, which are the steered wheels, and is steered manually by the worker during manual operation, and automatically steers by a steering device 31 (see Figure 4) that is configured including a steering actuator, steering cylinder, etc. (not shown) during automatic operation.

[0022] The transmission case 10 houses a transmission (speed change device 32). The power (rotational power) output from the engine E is appropriately reduced (shifted) by the transmission and transmitted to the front wheels 4 and rear wheels 5, as well as transmitted (supplied) to the PTO shaft 16. The transmission case 10 also houses a PTO forward / reverse clutch, a PTO speed change unit, etc., and makes it possible to control the transmission (on / off, speed change) of power to the PTO shaft. This enables the work vehicle A to control the drive of the work implement W.

[0023] A work implement W that performs work in the field is connected to the rear of the traveling body 2, and a PTO shaft 16 that transmits power to drive the work implement W protrudes rearward from the transmission case 10. The PTO shaft 16 transmits rotational power that has been appropriately reduced by the transmission to the work implement W that is attached to at least the rear of the traveling body 2.

[0024] In addition, a lifting device 12 that raises and lowers the work implement W is provided at the rear of the traveling body 2. The lifting device 12 raises the work implement W to move it to a non-working position. The non-working position is a position where the work implement W is raised when, for example, the traveling body 2 moves backward or turns. In addition, the lifting device 12 lowers the work implement W to move it to a ground work position. The lifting device 12 includes a hydraulic lifting cylinder 121, a lift arm 122, a lift rod 123, a lower link 124, and a top link 125.

[0025] When hydraulic oil is supplied to the lift cylinder 121, the lift arm 122 rotates around the axis AX, which serves as the rotation fulcrum, to raise the work implement W, and when hydraulic oil is discharged from the lift cylinder 121, the lift arm 122 rotates around the axis AX to lower the work implement W. A lift arm sensor 26 that detects the rotation angle of the lift arm 122 is provided at the base of the lift arm 122 (near the axis AX). The height of the work implement W is calculated based on the detection result of the lift arm sensor 26. In this way, by extending and retracting the lift cylinder 121, the position of the work implement W can be switched between a working position where the work implement W is lowered to perform work (in other words, a height position where the tillage body w3, described later, touches the ground), and a non-working position where the work implement W is raised to perform no work (in other words, a height position where the tillage body w3, described later, does not touch the ground).

[0026] The positioning device 30 is, for example, a GNSS (Global Navigation Satellite System) antenna, and can perform positioning and timing by receiving radio waves from navigation satellites S orbiting the sky. It can also calculate the traveling speed from the history of positioning results and the Doppler effect of radio waves. During autonomous driving, a control device C (described later) acquires positioning information (in other words, vehicle position information) from the positioning device 30 to calculate the vehicle's position, and controls the steering device 51 to eliminate deviation from a predetermined target driving route, thereby enabling autonomous driving. The positioning device 30 also includes an IMU (Inertial Measurement Unit), which can simultaneously measure the tilt angle of the traveling vehicle body 2 (i.e., the tilt of the field).

[0027] The lift arm 122 is connected to the lower link 124 via the lift rod 123. In this way, the lifting device 12 connects the work machine W to the traveling body 2 via the lower link 124 and the top link 125 so that the work machine W can be raised and lowered. The lower link 124 is attached to the rear of the transmission case 10.

[0028] The tractor 1 also allows the operator to set various tasks for a specific field by operating an information processing terminal (a mobile terminal such as a tablet terminal) 100. The information processing terminal 100 includes a storage unit configured with, for example, a hard disk, a ROM (Read Only Memory), a RAM (Random Access Memory), and the like, and a display unit and operation unit configured with a touch panel 101. Note that various keys, buttons, and the like may be provided separately as the operation unit.

[0029] The work implement W is a machine that performs work in a field (in this embodiment, tilling). In this embodiment, the work implement W is a rotary tiller that performs tilling work in the field, and performs tilling and leveling work while moving in the direction of travel across the field by the travel of the tractor 1. However, the work implement W is not limited to a tiller, and other work implements such as a seed sower, lawn mower, snow blower, etc. may also be used.

[0030] <2. Work vehicle sensors> Next, the group of sensors N arranged on the tractor 1 will be described.

[0031] The tractor 1 is equipped with a sensor group N consisting of multiple sensors that acquire various detection and sensing information required during work and transmit it to the control device C described below.The sensor group N includes, for example, the following sensors.

[0032] The obstacle sensor 20 functions to detect obstacles (people or objects) around the aircraft. This obstacle sensor 20 is a medium-range sensor, preferably an infrared sensor, that can detect obstacles by emitting an infrared beam and detecting the light reflected from the obstacle. In addition, the distance to the obstacle can be measured by measuring the time between emitting the infrared beam and detecting the light reflected from the obstacle. The obstacle sensor 20, which is an infrared sensor, detects obstacles two-dimensionally, with a detection range of, for example, several meters to several tens of meters. Note that other medium-range sensors, such as sonar or millimeter-wave radar, can also be used as the obstacle sensor 20, or a combination of these can be used.

[0033] The obstacle sensor 20 includes a front sensor 21 and a rear sensor 22. The front sensor 21 has a detection area that extends forward of the vehicle body, and the rear sensor 22 has a detection area that extends rearward of the vehicle body. The front sensor 21 is disposed at the front of the traveling vehicle body 2, for example, by being attached to a sensor mounting stay 13 provided in front of the hood 6, and detects obstacles (people or objects) that exist in front of the traveling vehicle body 2. The rear sensor 22 is disposed at the upper rear of the traveling vehicle body 2, for example, by being attached to the top of the cabin 7a, and detects obstacles that exist behind the traveling vehicle body 2. The angle of the rear sensor 22 relative to the cabin 7a, i.e., the traveling vehicle body 2, can be changed by a motor (not shown).

[0034] Although not described in detail, the tractor 1 also includes, as a sensor group N, in addition to the above-mentioned lift arm sensor 26, an engine rotation sensor 23 that detects the engine rotation speed, a vehicle speed sensor 24 that detects the vehicle speed, a steering angle sensor 25 that detects the steering angle of the front wheels 4, which are the steered wheels, and the like, each arranged at an appropriate position.

[0035] <3. Configuration of various control devices in the control section> FIG. 2 is an explanatory diagram of the operating devices located in front of the cockpit 8.

[0036] Next, various operating devices provided around the steering wheel 9 will be described with reference to Fig. 2. Fig. 2 is an explanatory diagram of the operating devices located in front of the cockpit 8. Note that the types and locations of the operating devices shown in each figure are merely examples and are not limited to these.

[0037] As shown in Figure 2, as described above, the steering wheel 9 is provided in front of the driver's seat 8 (see Figure 1). In addition, the clutch pedal 18 is provided on the lower left side of the handle post 350 to which the steering wheel 9 is attached, and the accelerator pedal 19 and the left and right brake pedals 15 (15L, 15R) are provided on the lower right side of the handle post 350.

[0038] A forward / reverse lever 201 is provided on the upper left side of the handle post 350. An accelerator lever 351 for adjusting the rotation speed of the engine E and a blinker lever 352 are provided on the upper right side of the handle post 350. An engine key switch 353 for operating the drive (on / off) of the engine E is also provided on the right side of the handle post 350, and a PTO shift lever 354 is provided in the center.

[0039] A dashboard cover 355 is provided in front of the steering wheel 9. The dashboard cover 355 also has a meter panel 11 mounted thereon so as to be visible to the driver in the cockpit 8. The meter panel 11 also has a display unit (liquid crystal monitor) 356, an engine revolution meter (tachometer) 357, and the like. The liquid crystal monitor 356 displays various information such as a gear display that displays the current gear, a fuel consumption rate display, and a traveling speed display, and the fuel consumption rate display and the traveling speed display may be displayed so as to switch at regular intervals.

[0040] 2, a correction amount operation unit B is provided on the handle post 350 at the lower left side of the position where the steering wheel 9 is disposed. This correction amount operation unit B will be described below. Note that the correction amount operation unit B may also be disposed at the upper right side of the position where the steering wheel 9 is disposed.

[0041] <4. Configuration of the correction amount operation section> FIG. 3(a) is a schematic plan view of the correction amount operation unit, FIG. 3(b) is a schematic side view as seen from the cockpit side, and FIG. 3(c) is a schematic plan view explaining the operation position of the correction amount operation unit.

[0042] The work vehicle 1 is equipped with a correction amount operation unit B that receives operation from the worker and adjusts the shift amount. The correction amount operation unit B is, for example, a microswitch-type lever that can be input in four directions, and is configured so that the operation position can be detected by multiple contact sensors (not shown).

[0043] The lever B1 receives input from the operator and determines the position of the lever B1, and includes a guide groove B2 that guides the operating direction of the lever B1. The guide groove B2 is formed by cutting out a roughly cross-shaped notch in a base B3 to which the lower end of the lever B1 is attached, and serves to guide the operating direction of the lever B1 and also define the operating range. This allows the operator to grasp the upper end of the lever B1 and tilt the lever B1 forward, backward, left, or right (tilt it diagonally) along the guide groove B2. The correction amount operating unit B is configured to allow input in four directions, forward, backward, left, and right, based on a neutral position b1 where the lever B1 is roughly upright. More specifically, as shown in FIG. 3, the correction amount operation unit B can be operated to a right position b2 which is an operation position in the right direction, a rightmost position b3, a left position b4 which is an operation position in the left direction, a leftmost position b5, a front position b6 which is an operation position in the forward direction, and a rear position b7 which is an operation position in the backward direction, relative to a neutral position b1 which is an initial position and a reference operation position.

[0044] Here, the correction amount operating unit B is configured such that when the lever unit B2 is operated to any of the neutral position b1, right position b2, and left position b4, the lever unit B2 is locked by a fixed contact (not shown) provided corresponding to each operating position, thereby maintaining that operating position unless the lever unit B2 is operated again by the operator.

[0045] The correction amount operation unit B can be operated by tilting the lever B1 further to the right from the right position b2 to the rightmost position b3. The lever B1 can also be tilted further to the left from the left position b4 to the leftmost position b5. When the correction amount operation unit B is tilted to the right of the right position b2 or to the left of the left position b4, a biasing force acts in a direction to push the lever B1 back by an elastic member (e.g., a spring or silicone rubber) (not shown). Therefore, if the operator applies an external force to the right and stops (e.g., releases) the lever B1 after it has been operated to the rightmost position b3, the biasing force returns the lever B1 to the right position b2. Similarly, when no external force is applied to the left, the biasing force returns the lever B1 from the leftmost position b5 to the left position b4. In other words, the right end position b3 and the left end position b5 are configured so that the operating positions can be maintained only when the operator applies an external force to the lever portion B1 in the direction of the operating positions.

[0046] Similarly, when the lever member B1 is tilted to the forward position b6 or the rearward position b7, a biasing force acts by an elastic member (not shown) in a direction to push the lever B1 back. Therefore, when an operator applies an external force forward to the lever B1 and stops the operation while operating it in the forward position, the biasing force returns the operating position of the lever B1 to the neutral position b1. Similarly, when the operator does not apply an external force to the rearward position b7, the biasing force returns the lever B1 from the rearward position b7 to the neutral position b1. Thus, the forward position b6 and the rearward position b7 are configured to maintain their operating positions only when the operator applies an external force to the lever B1 in the direction of the operating position.

[0047] <5. Control device peripheral configuration> FIG. 4 is a block diagram showing the configuration of the control device C and its surroundings of the work vehicle A. As shown in FIG.

[0048] The control device C is an information processing device configured by combining multiple ECUs (Electronic Control Units). Each of the multiple ECUs is configured with a CPU that performs arithmetic processing and a memory that can read and write information required for the arithmetic processing. The CPU operates in accordance with various control programs stored in the memory, thereby realizing the configuration shown as functional blocks in Fig. 4.

[0049] The control device C is equipped with an ECU for controlling each mechanism of the vehicle body, and more specifically, it is equipped with an operation system ECU 50 that controls the operation of each mechanism of the work vehicle 1, and a control system ECU 54 that determines the operation method (operation rules) of each mechanism.

[0050] Here, as shown in Figure 4, the operation system ECU 50 includes an engine ECU 51 that controls the operation of the engine E, a traveling system ECU 52 that controls the operation of mechanisms related to traveling such as the steering device 31, the transmission 32, and the braking device 33, and a work machine ECU 53 that controls the operation (lifting and lowering) of the lifting device 12.

[0051] The control device C is also connected to the input side with the positioning device 30 and the sensor group N, from which it is able to acquire detection information. It is also connected with the forward / reverse lever 201, accelerator lever 351, turn signal lever 352, engine key switch 353, PTO shift lever 354, and correction amount operation unit B, from which it is able to acquire information relating to the operation of these.

[0052] The output side is connected to the engine E, steering device 31, transmission 32, braking device 33, lifting device 12, etc., and is capable of transmitting control signals to these devices and mechanisms. It is also capable of transmitting various information to be displayed on the display unit 356. The control device C is equipped with a communication unit 60, which is a communication mechanism that connects with external devices physically separated from the control device C via a network NW and exchanges information through communication. In this embodiment, the communication unit 60 is connected to at least the mobile information terminal 100, and is capable of sending and receiving information.

[0053] Here, as described above, the steering device 31 is configured to include a steering actuator, a steering cylinder 31s, etc., and is a device that automatically steers the steering wheel 9 during automatic driving. The speed change device 32 is a transmission housed in the transmission case 10, and is a device that changes the speed of the rotational power output from the engine E. In addition, the braking device 33 is configured to include left and right brake cylinders, left and right brake devices, etc., and is a device that brakes the aircraft.

[0054] <6. Control examples using control devices (control ECUs)> The configuration of the control system ECU 54 will be described in more detail below, along with control examples. The control system ECU 54 includes, as control programs, a travel control unit 56 that controls the travel of the vehicle, and a travel route determination unit 57 that determines the travel route during automatic driving.

[0055] The control system ECU 54 also has a work information database DB in which work information, which is information related to work, is stored. The work information includes, for example, field information, which is information related to the field, information related to the planned travel line, information related to the registered reference position (described later), and information related to the working width of the work implement W. Furthermore, the field information includes field information necessary for the work, such as information on the shape, position, size, area, ridge position, latitude, longitude, and altitude of each field to be worked on.

[0056] [Control example] (I) Manual driving mode, automatic driving mode, road driving mode The driving control unit 56 includes a manual driving control unit 56a that controls driving in manual driving mode, an automatic driving control unit 56b that controls driving in automatic driving mode, and an on-road driving control unit 56c that controls driving in on-road driving mode 56c. Here, controlling driving means, more specifically, acquiring necessary detection information from the sensor group N to execute each mode, and sending necessary control commands to the operating ECU 50 when each mode is selected.

[0057] Each driving mode is well known and will not be described in detail, but in the automatic driving mode, the steering device 51 is controlled so that the vehicle travels along the planned driving line L2 (see FIG. 5, etc.) based on the measurement results of the positioning device 30. Note that other components such as the engine E, the transmission 52, the braking device 33, and the lifting device 12 may also be configured to be controlled.

[0058] In the manual driving mode, the operator can steer the machine by operating the steering wheel 9 to travel in a field. Similarly, in the road driving mode, the operator can steer the machine by operating the steering wheel 9 to travel on the road, but as described above, the upper limit of the vehicle speed is controlled so that the machine can travel at low speeds in the manual driving mode and at high speeds in the road driving mode.

[0059] (II) Registering the driving reference line and setting the planned driving line When the work vehicle 1 is driven automatically, it registers a driving reference line L1 and sets a planned driving line L2. The driving route determination unit 57 includes a driving reference line registration unit 57a that registers the driving reference line L1, a planned driving line setting unit 57b that sets the planned driving line, and a correction amount adjustment unit 57c that adjusts the shift amount during automatic driving.

[0060] FIG. 5 is an explanatory diagram relating to automatic driving of a work vehicle.

[0061] As shown in Fig. 5, when performing automatic driving, first a travel reference line L1 is set before performing automatic driving. After setting the travel reference line L1, a planned travel line L2 parallel to the travel reference line L1 is set, thereby enabling automatic driving in which the work vehicle 1 is automatically steered along the planned travel line L2. In other words, during automatic driving, the control device C is configured to automatically steer the direction of travel of the work vehicle 1 so that the vehicle body position measured by the positioning device 30 matches the planned travel line L2 (so that any deviation is eliminated).

[0062] Specifically, before performing automatic driving, the operator moves the work vehicle 1 to a predetermined position in the field (step S1), and when the operator performs a predetermined operation (described later) on the correction amount operation unit B at the desired position (step S2), the traveling reference line registration unit 57a registers the vehicle's position measured by the positioning device 30 as the reference position Ps of the start point of the traveling reference line L1 (step S3). Next, the work vehicle 1 is moved from the start point Ps of the traveling reference line L1 (step S4), and when the operator again performs a predetermined operation (described later) on the correction amount operation unit B at the desired position (step S5), the traveling reference line registration unit 57a registers the vehicle's position measured by the positioning device 40 as the end point Pe of the traveling reference line L1 (step S6). As a result, a straight line connecting the start point Ps and the end point Pe is set as the traveling reference line L1 based on the position information measured by the positioning device 30. The set travel reference line L1 and the position information of the start point Ps and end point Pe are registered (recorded) in the work information database DB.

[0063] After the travel reference line L1 is set, for example, the work vehicle 1 is moved to a location different from the location where the travel reference line L1 was set by automatic or manual travel along the turning path Lt (step S7), and when the worker performs a predetermined operation to start automatic driving (for example, turning on an automatic driving changeover switch, not shown) (step S8), the planned travel line setting unit 57b calculates and sets the planned travel line L2, which is a straight line parallel to the travel reference line L1 (step S9). After the planned travel line L2 is set, the automatic driving control unit 56b calculates a deviation based on the vehicle's position information, and controls the steering device 31 in a direction to eliminate the deviation, thereby starting automatic steering. As a result, the direction of the steered wheels (in this embodiment, the front wheels 4) is automatically changed so that the traveling direction of the work vehicle 1 is aligned with the planned travel line L2. During automatic driving, the travelling speed (vehicle speed) of the work vehicle 1 can be changed by the operator manually changing the amount of operation of the accelerator member (accelerator pedal 19, accelerator lever 351) or by changing the gear stage of the transmission 32.

[0064] Furthermore, after automatic steering has begun, if the operator performs a predetermined operation to end automatic driving (for example, turning off an automatic driving changeover switch, not shown) at any point (step S10), automatic driving (automatic steering) can be ended (step S11). In other words, the end point of the planned travel line L2 can be set by performing a predetermined operation to end automatic driving. Thereafter, by repeating the procedures of steps S7 to S11, it becomes possible to work with the work implement W while efficiently traveling back and forth in the field.

[0065] (III) Adjustment of correction amount If an error (deviation) occurs between the vehicle's position measured by the positioning device 30 and the actual vehicle's position during automatic driving, the work vehicle 1 will deviate from the planned travel line L2, but the correction amount adjustment unit 57c, which has accepted the operation of the correction amount operation unit B, can shift (move) the vehicle in the left / right direction by the amount of deviation, returning it to the planned travel line L2. Details will be explained below. In the following explanation, left and right not only mean left and right with respect to the vehicle's traveling direction, but also refer to the direction perpendicular to the planned travel line L2.

[0066] <7. Correcting the amount of misalignment> 6(a) to 6(c) are explanatory diagrams relating to correction of the amount of deviation of the work vehicle 1. FIG.

[0067] The work vehicle 1 can eliminate the discrepancy between the vehicle position measured by the positioning device 30 and the actual vehicle position by using the correction amount adjustment unit 57c in accordance with the operation of the correction amount operation unit B. First, the relationship between the vehicle position Pm measured by the positioning device 30, the actual vehicle position Pa, the deviation amount De which is the error therebetween, and the left and right correction amounts Df will be described with reference to Figures 6(a) and 6(b).

[0068] 6(a) shows a state in which an error (deviation) has occurred between the actual vehicle position Pm and the vehicle position Pm measured by the positioning device 30, by an amount of deviation De to the right of the actual vehicle position Pa. Note that the figure also shows a virtual vehicle 1' at the vehicle position Pm measured by the positioning device 30. As shown in the figure, due to the error (deviation), the work vehicle 1 is traveling deviating to the left from the planned traveling line L2.

[0069] At this time, as shown in FIG. 6(b), the operator can correct the vehicle position Pm measured by the positioning device 30 to the left by setting a leftward correction amount (left) Df for the deviation amount De occurring to the right from the actual vehicle position Pa through a predetermined operation (described later) of the correction amount operation unit B. The corrected vehicle position Pc is shown in the figure, and when the corrected vehicle position Pc matches the actual vehicle position Pa, the work vehicle 1 can move to the right by the shift amount Ds through automatic driving and return to the intended travel line L2, as shown in FIG. 6(c). At this time, the shift amount Ds and the deviation amount De are values ​​that indicate approximately the same distance in the left-right direction. The same is true for the correction amount Df.

[0070] In addition, Figures 6(a) to 6(c) show an example in which the actual vehicle position Pm measured by the positioning device 30 has an error (deviation) to the right of the actual vehicle position Pa by an amount De, and the vehicle position Pm measured by the positioning device 30 is corrected to the left by setting a correction amount (left) Df to the left.However, in the case in which an error (deviation) to the left of the actual vehicle position Pa by an amount De has occurred, the work vehicle 1 can be moved to the left by the shift amount Ds and returned to the planned traveling line L2 by setting a correction amount (left) Df to the right in a similar manner.

[0071] Here, the correction amount refers to a setting value for correcting the aircraft position measured by the positioning device 30. The correction amount is expressed, for example, as an integer value greater than or equal to 0, and a correction amount for the left direction (left) and a correction amount for the right direction (right) are set. Note that the correction amount is a setting value for correcting the aircraft position that serves as the reference for automatic steering in either the left or right direction from the aircraft position measured by the positioning device 30. Therefore, when the correction amount for the left direction (left) is greater than 0, the correction amount for the right direction (right) is 0, and when the correction amount for the right direction (right) is greater than 0, the correction amount for the left direction (left) is also 0.

[0072] As described above, if an error occurs in the positioning by the positioning device 30, the vehicle will travel off the planned travel line L2, but in order to make the vehicle travel on the planned travel line L2, it becomes necessary to correct the vehicle position Pa measured by the positioning device 30 to eliminate the error. In other words, when an error occurs in the positioning by the positioning device 30, it becomes necessary to correct the measured vehicle position Pa so that it matches the actual vehicle position Pa.

[0073] Therefore, in this embodiment, the correction amount consists of a correction amount (right) that indicates the correction amount in the right direction and a correction amount (left) that indicates the correction amount in the left direction. Here, when the correction amount (right) and the correction amount (left) are set to 0, during automatic driving, the vehicle position Pa measured by the positioning device 30 becomes the vehicle position that serves as the reference when calculating the deviation from the planned driving line.

[0074] On the other hand, when the set value of the correction amount (right) is greater than 0, the larger the value, the more the vehicle moves (shifts) to the left relative to the position when the correction amount (right) is 0 (i.e., the leftward shift amount Ds increases). At this time, the vehicle position Pc, which serves as the reference when calculating the deviation from the planned driving line L2, is moved to the left (shifted leftward) relative to the vehicle position Pm measured by the positioning device 30, depending on the magnitude of the correction amount (right). As a result, during automatic driving, the larger the set value of the correction amount (right), the more to the left of the vehicle position Pm measured by the positioning device 30 becomes the reference position, and the vehicle will move (shift leftward) relative to the reference position when the correction amount (right) is 0.

[0075] Similarly, when the set value of the correction amount (left) is greater than 0, the larger the value, the more the vehicle moves (shifts) to the right relative to the vehicle position when the correction amount (left) is 0 (i.e., the rightward shift amount Ds increases). At this time, the vehicle position Pc, which serves as the reference when calculating the deviation from the planned driving line, is moved to the left (shifted leftward) relative to the vehicle position Pm measured by the positioning device 30, depending on the magnitude of the correction amount (left). As a result, during autonomous driving, the larger the set value of the correction amount (left), the more to the left of the vehicle position Pm measured by the positioning device 30 becomes the reference position, and the vehicle moves (shifts rightward) relative to the reference position Pa when the correction amount (left) is 0. As a result, by adjusting the set values ​​of the correction amount (left) and correction amount (right) by operating the correction amount operation unit B, the work vehicle 1 can correct the measured vehicle position Pm to match the actual vehicle position Pa when an error or the like occurs in the positioning by the positioning device 30.

[0076] <8. Operation position of the correction amount operation section and correspondence between each mode and function> The correction amount adjustment unit 57c acquires operation information of the correction amount operation unit B and executes the following processing. Fig. 7 is an explanatory diagram showing the correspondence between the operation position of the correction amount operation unit B and the processing executed by the control device C. Fig. 8 is a state transition diagram showing the relationship between the operation position of the correction amount operation unit B and the mode and function executed by that operation position. Fig. 9 is a table showing the relationship between each mode and function in Fig. 8 and the operation position of the correction amount operation unit.

[0077] 7 and 8, the work vehicle 1 is configured so that the mode of the control device C and the processing to be executed are switched by operating the correction amount operating unit B. Also, as shown in Fig. 9, the processing to be executed is changed depending on the operating position of the correction amount operating unit B, depending on the mode currently being executed.

[0078] Here, as shown in FIG. 7, the neutral position b1 of the correction amount operation unit B is an operation position that performs the function of switching to one of the neutral mode, left-neutral transition mode, and right-neutral transition mode. The right position b2 and the rightmost position b3 are operation positions that perform the function of switching to the right shift mode. The left position b3 and the leftmost position b4 are operation positions that perform the function of switching to the left shift mode. The front position b6 is an operation position that performs the function of switching whether or not automatic driving is enabled (permitted or not). The rear position b7 is an operation position that performs the function of registering a reference position. Each mode and function will be described below.

[0079] <9. Modes that the control device can execute> In the neutral mode, during automatic driving, the correction amount (left) and correction amount (right) are 0, and automatic steering is performed to eliminate the deviation of the position from the intended traveling line L2 based on the measured vehicle position Pm (hereinafter also referred to as the neutral position), causing the vehicle to travel (in other words, traveling in the neutral position). In other words, during automatic driving, if there is no error (deviation) between the vehicle position Pm measured by the positioning device 30 and the actual vehicle position Pa, it is preferable that the work vehicle 1 be automatically driven in the neutral mode.

[0080] The right shift mode is a mode in which the vehicle is shifted to the right from a neutral position during driving. More specifically, during automatic driving, the vehicle is shifted (moved) to the right in response to automatic steering based on the vehicle position Pm measured by the positioning device 30 (i.e., in neutral mode) and driven (in other words, driven in a right shift position shifted to the right from the neutral position). More specifically, if an error (deviation) occurs to the right between the vehicle position Pm measured by the positioning device 30 and the actual vehicle position Pa, causing the vehicle to deviate from the planned driving line L2 and drive to the left, it is preferable to automatically drive the vehicle in the right shift mode to eliminate the error (deviation) to the right of the positioning device 30. Note that in the right shift mode, the correction amount (left) is greater than 0, and the correction amount (right) is 0.

[0081] The left shift mode is a mode in which the vehicle is shifted to the left from a neutral position during driving. More specifically, during automatic driving, the vehicle is shifted (moved) to the left (in other words, driven in a left shift position shifted to the left from the neutral position) relative to automatic driving based on the vehicle position Pm measured by the positioning device 30 (i.e., neutral mode). More specifically, when an error (deviation) occurs to the left between the vehicle position Pm measured by the positioning device 30 and the actual vehicle position Pa, causing the vehicle to deviate from the planned driving line L2 and drive to the right, it is preferable to automatically drive the vehicle in the right shift mode to eliminate the leftward error (deviation) of the positioning device 30. Note that in the left shift mode, the correction amount (right) is greater than 0, and the correction amount (left) is 0.

[0082] The right-neutral transition mode is an intermediate mode when transitioning from the right shift mode to the neutral mode. In the right-neutral transition mode, the control device C gradually moves the vehicle from the right shift position to the neutral position while driving. In other words, the correction amount (left) is gradually reduced at a constant speed until it approaches zero. When the correction amount (left) reaches zero, the vehicle transitions to the neutral mode. Note that the rate at which the correction amount (left) is reduced is slower than the rate at which the correction amount (left) is increased in the right shift mode. As a result, when transitioning from the right-neutral transition mode to the right shift mode again (EV13), the vehicle's lateral movement speed is slower, making it easier to adjust the vehicle to the intended travel line L2 and improving operability and safety.

[0083] The left neutral transition mode is an intermediate mode when transitioning from the left shift mode to the neutral mode, and in the left neutral transition mode, the control device C gradually moves the vehicle from the left shift position to the neutral position b1 while traveling. In other words, the correction amount (right) is gradually reduced at a constant speed until it approaches 0. When the correction amount (right) becomes 0, the vehicle transitions to the neutral mode.

[0084] Next, with reference to Figures 8 and 9, the processing of the control device C in response to the operation of the correction amount operation unit B will be described. When automatic driving begins, the neutral mode is selected as the initial mode. Also, it is assumed that the initial operating position of the correction amount operation unit B is operated to the neutral position b1. At this time, the work vehicle 1 automatically drives along the planned travel line L2, using the vehicle position Pm measured by the positioning device 30 as a reference.

[0085] If an error (deviation) occurs between the vehicle position Pm measured by the positioning device 30 and the actual vehicle position Pa, causing the work vehicle 1 to deviate to the left relative to the planned travel line L2, the worker, recognizing this, tilts the lever B1 to the right (to operating position b2 or operating position b3), thereby transitioning from neutral mode to right shift mode (EV1). In right shift mode, when the lever is at operating position b2, the value of the correction amount (left) is maintained, and when the lever is at operating position b3, the value of the correction amount (left) is increased. More specifically, while the lever is at operating position b3, the value of the correction amount (left) is increased at a constant speed according to the operation time (see FIG. 9). At this time, when the value of the correction amount (left) reaches a predetermined upper limit, the increase stops, and the worker is notified that the correction amount has reached the upper limit by means of an alert displayed on the display unit 356, a buzzer, or other means.

[0086] As a result, the machine body shifts to the right at a constant speed (for example, several centimeters or tens of centimeters per second), so the operator can easily adjust the machine body's position to the planned traveling line L2 by operating it to the rightmost position b3 until it returns to the planned traveling line L2. After the machine body returns to the planned traveling line L2, if the operator stops operating the lever part B1, it automatically returns to the right position b2, so the value of the correction amount (left) can be maintained. This makes it possible to quickly adjust the value of the correction amount (left). In addition, fine adjustment of the correction amount (left) can be easily made by operating the two positions of the right position b2 and the rightmost position b3.

[0087] Here, in the right shift mode, if the error (deviation) in the right direction between the machine's position Pm measured by the positioning device 30 and the actual machine's position Pa is eliminated or reduced, the machine, which has been positioned on the planned travel line L2 by shifting to the right, will deviate to the right from the planned travel line L2. Recognizing this, the operator tilts the lever B1 to the neutral position b1, causing the control device C to transition from the right shift mode to the right neutral transition mode (EV12). Note that, assuming an erroneous operation to the left beyond the neutral position b1, the control device C may also be configured to transition to the right neutral transition mode when the lever is operated to the left position b4 or the leftmost position b5 (EV12).

[0088] As a result, the control device C gradually reduces the correction amount (left) at a constant speed until it approaches 0. As a result, the vehicle gradually shifts leftward until it reaches the neutral position, allowing it to return to the intended travel line L2. When the lever B1 is tilted to the neutral position b1 (EV12), the control device C stores the value of the correction amount (left) at that time in the work information database DB. This stored value of the correction amount (left) is read out and set as the value of the correction amount (left) when the vehicle transitions from the neutral mode to the right shift mode again (EV11). This makes it possible to quickly reset the value of the correction amount (left) by utilizing the history from the previous shift, thereby improving work efficiency. Note that this history may be reset when transitioning to the next process (when automatic operation ends). When the correction amount (left) becomes 0 in the right-neutral transition mode, the control device C transitions from the right-neutral transition mode to the neutral mode (EV14). At this time, the operator is notified that the machine has returned to the neutral position by means of an alert display on the display unit 356, a buzzer, or the like.

[0089] Here, if the operator recognizes that the machine has returned to the intended travel line L2 before shifting left to the neutral position during the right-neutral transition mode (that is, if the error (deviation) in the right direction is reduced, the machine will return to the intended travel line L2 before returning to the neutral position), he or she can transition back to the right shift mode (EV13) by tilting the lever section B1 to the right from the neutral position b1 (to the right position b2 or the rightmost position b3). This allows for a quick adjustment so that the machine is positioned on the intended travel line L2 with a single touch, and prevents the machine, which has shifted rightward, from passing over the intended travel line L2 and deviating further to the right.

[0090] The right shift mode and right neutral transition mode have been described above. The left shift mode and left neutral transition mode have the same configuration except for the left-right direction, so a description thereof will be omitted. According to the configuration in which the vehicle position measured by the positioning device 30 is corrected by operating the correction amount operation unit B, even if an error occurs in the vehicle position measured by the positioning device 30, the vehicle can be quickly returned to the intended traveling line L2 with an extremely simple operation. As a result, the operation switch for eliminating the positional deviation between the intended traveling line L2 and the vehicle can be easily operated, and fine adjustment of the vehicle position is also easy. Furthermore, whereas the conventional operation for returning the vehicle from a state in which it has been shifted left or right to the neutral position was complicated, the above configuration allows the vehicle's traveling position to be returned to the neutral position with a simple operation.

[0091] When the operation position of the correction amount operation unit B is operated to the front position b6, the control device C is configured to be able to switch between automatic driving permission and non-permission (permission or non-permission) (EV31, EV32). For safety reasons, automatic driving is performed only when automatic driving is permitted, and when automatic driving is not permitted, automatic driving will not start even if a predetermined operation to start automatic driving is performed.

[0092] Furthermore, when the operation position of the correction amount operation unit B is operated to the rear position b6, the control device C is configured to acquire position information of the operated point from the positioning device 30 and register it as a reference position (EV41, EV42). This makes it possible to register the reference position with a quick and simple operation (see FIG. 5).

[0093] The embodiments of the present invention have been described above. The present invention is not limited to the above-described embodiments. It goes without saying that modifications may be made as appropriate within the scope of the technical concept. Other embodiments will be described below.

[0094] <10. Modifications> In the above embodiment, while the rightmost position b3 (leftmost position b5) is being operated, the value of the correction amount (left) (correction amount (right)) is increased at a constant speed depending on the operation time, but the correction amount (left) (correction amount (right)) may also be increased depending on the number of times the rightmost position b3 (leftmost position b5) is operated. In other words, the correction amount (left) (correction amount (right)) can be increased by a constant value each time the rightmost position b3 (leftmost position b5) is operated.

[0095] The correction amount operation unit B can also be configured so that it can be operated only in two directions, left and right, from the neutral position b1, omitting operation to the forward position b6 and rearward position b7. This limits the function of the correction amount operation unit B to shifting the aircraft in the left and right directions, thereby preventing erroneous operation in the forward and backward directions.

[0096] <11. Other embodiments> 10(a) and 10(b) are schematic front views of an operation panel provided on the control unit 7 of a work vehicle 1 according to another embodiment.

[0097] As shown in FIGS. 10(a) and 10(b), the operation panel 350a may be configured to operate a three-position switch unit 350b to switch to manual mode (manual driving) when the motor is operating. The operating unit may be provided with a wedge-shaped fixing member 350c that interferes with the three-position switch unit 350b and fixes it in the manual mode position when the motor is operating. In robot mode (autonomous driving permitted) and during autonomous driving, when the vehicle is stopped due to an abnormality being detected, the three-position switch unit 350b may be operated by a motor or the like to switch to manual mode (manual driving). During manual driving, the system may be configured to automatically disable autonomous driving if the travel distance exceeds a certain level. The GNSS reception status may be classified into multiple modes, allowing transition to robot mode when the position accuracy is high, enabling steering operation assistance during driving when the position accuracy is medium, and prohibiting these controls when the position accuracy is low. In the case where the field shape has been acquired in robot mode, manual mode, and teaching mode, and the vehicle deviates from the field area, transition to automatic mode may be prohibited and a monitor or the like may be notified that mode switching is not possible. In the case where the vehicle is traveling in robot mode and manual mode and the vehicle has traveled for a certain period of time without detecting the operator sitting in the seat, the control may be configured to stop the vehicle. In the case where the vehicle is traveling in robot mode and manual mode and the vehicle is detected to have tilted at a certain angle or more with respect to the horizontal plane, transition to automatic mode may be prohibited and a monitor or the like may be notified that mode switching is not possible. The three-position switch may be configured to be used for mode switching of a function that only provides steering operation assistance while traveling when not in robot mode. In the case where the field shape has not been acquired while traveling in robot mode and teaching mode, operation of the three-position switch may not result in transition to automatic mode, and traveling operations such as forward and reverse movement of the vehicle may not be accepted. If the presence of an operator in the seat is not detected when switching to automatic mode, the automatic mode will not be switched over even if the three-position switch is operated, and driving operations such as forward and backward movement of the machine may not be accepted.The robot may be configured to have a means for informing the operator to take a seat when switching to automatic mode after acquiring the shape of the field while traveling in robot mode and teaching mode.

[0098] FIG. 11 is an explanatory diagram relating to the design of a work vehicle according to another embodiment.

[0099] As shown in FIG. 11, a rice transplanter equipped with a robot mode that automatically performs planting work based on a field shape that has been taught in advance, provided that the presence of an operator is detected, may be configured to include a switch to enable transition to robot mode and a three-position switch to switch between teaching, manual, and automatic driving modes. During the ridge-aligning process of the automatically driven rice transplanter, forward movement may be performed using a seesaw switch. By switching the robot mode on and off, it may be possible to switch between straight-line assist mode and automatic driving mode. By switching the robot mode switch on and off, it may be possible to switch between robot mode and turning assist mode using a three-position switch, and it may be possible to switch between robot mode and turning assist mode using a single switch. It may also be possible to use a seesaw switch to adjust the vehicle speed during automatic driving. [Explanation of symbols]

[0100] 1 Work vehicle 2 Running vehicle 3 Body frame 4 front wheels 5 rear wheels 6. Bonnet 7 Control Unit 7a Cabin 8. Cockpit 9. Steering wheel 12 Lifting device 20 Obstacle Sensor 21 Front sensor 22 Rear sensor 26 Lift arm sensor 30 Positioning device 36 Engine key switch 100 Mobile Information Terminals 101 Touch Panel B Correction amount operation section E-Engine S navigation satellite W Work Machine

Claims

1. A correction amount operation unit mounted on a work vehicle and used to set a correction amount for automatic steering based on positioning, an operating member operable in two directions, left and right, from a neutral position, and the operating member can be selectively operated to a right position, a rightmost position, a left position, and a leftmost position; A work vehicle comprising: a biasing mechanism that applies a biasing force in a direction pushing the operating member back toward a neutral side when the operating member is operated to the rightmost position or the leftmost position.

2. A correction amount control method for performing automatic steering based on a traveling vehicle body position detected by a positioning device, comprising: Neutral mode, which performs automatic steering relative to a reference position; right shift mode, which shifts the vehicle body to the right by correcting the left; left shift mode, which shifts the vehicle body to the left by correcting the right; a right-neutral transition mode for transitioning from the right shift mode to neutral, and a left-neutral transition mode for transitioning from the left shift mode to neutral; 2. The work vehicle according to claim 1, wherein when the correction amount operation unit is operated to an end position, the correction amount is increased at a constant speed, whereas in the neutral transition mode the correction amount is decreased at a speed slower than the increasing speed to gradually return to neutral.

3. A program for executing correction amount control for a work vehicle, The correction amount at the time of transition from the right / left shift mode to each neutral transition mode is stored, 3. The work vehicle according to claim 2, wherein the stored value is set and restored when the mode is shifted again from the neutral mode to the right / left shift mode.

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