Work vehicles

Abstract

To appropriately stop automatic steering according to a state of an operator.SOLUTION: A work vehicle includes: an operation seat; a vehicle body capable of traveling either by manual steering by a steering wheel or automatic steering by a steering wheel performing steering in an advancing direction so as to match with a traveling planned line parallel to a traveling reference line; a positioning device capable of detecting a position of the vehicle body; a reference line setting switch for setting the position of the vehicle body detected by the positioning device to a start position and an end position of the traveling reference line; a steering changeover switch for changing the steering between the automatic steering and the manual steering; a seating detection device for detecting seating of an operator; a control device for permitting the automatic steering when the seating detection device detects seating and a changeover operation from the manual steering to the automatic steering is made by the steering changeover switch; and a notification device for notifying that the operator has left the operation seat. When the automatic steering is performed, the control device stops the automatic steering when the seating detection device does not detect seating.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to, for example, a work vehicle. [Background technology]

[0002] Conventionally, the agricultural work machine disclosed in Patent Document 1 is known. The agricultural work machine of Patent Document 1 includes a traveling body that can be switched between manual traveling by manual steering and automatic traveling by automatic steering along a set traveling line that is set parallel to a reference traveling line, and a changeover switch that can be switched between manual traveling and automatic traveling. In addition, the agricultural work machine sets the start point of the reference traveling line after pressing the right instruction button while traveling along a ridge, and sets the end point of the reference traveling line by pressing the left instruction button while traveling. That is, the reference traveling line is set before automatic steering. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2017-123803 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the agricultural machine of Patent Document 1, automatic driving can be easily performed by switching from manual driving to automatic driving with a changeover switch. The driver's intention must be reflected in the start and end of automatic driving, and stable steering must be performed in response to the driver's requests even during automatic driving. In addition, the driver is required to perform automatic driving in an appropriate state, and it is desirable for the driver to be in an appropriate state when starting and ending automatic driving.

[0005] In view of the above problems, an object of the present invention is to provide a work vehicle that can perform automatic steering appropriately according to the driver's state. [Means for solving the problem]

[0006] The technical means of the present invention for solving this technical problem is characterized by the following points.

[0007] The work vehicle comprises a driver's seat, a steering wheel, a vehicle body capable of traveling by either manual steering using the steering wheel or automatic steering of the steering wheel which steers the direction of travel so as to match a planned traveling line parallel to a traveling reference line, a prime mover provided on the vehicle body, a traveling device which causes the vehicle body to travel by the power of the prime mover, a positioning device capable of detecting the position of the vehicle body, a reference line setting switch which sets the position of the vehicle body detected by the positioning device to the start position and end position of the traveling reference line, a steering changeover switch which changes over between the automatic steering and the manual steering, a seating detection device which detects the driver being seated, a control device which allows the automatic steering when the seating detection device detects the driver being seated and an operation for switching from manual steering to automatic steering is performed by the steering changeover switch, and an alarm device which issues an alarm that the driver has left the driver's seat, and the control device is configured to detect when the seating detection device detects the driver being seated and the steering changeover switch detects that the driver is seated, From the seating detection state where the seating is detected The seating has not been detected Changed to absence detection state In case, When the notification is performed by the notification device and the progress of the absence detection state exceeds a predetermined determination threshold, The automatic steering and stopping the running of the vehicle body. .

[0009] The notification device increases the notification intensity as the absence detection state continues for a longer period of time. Effect of the Invention

[0010] According to the present invention, automatic steering can be stopped appropriately depending on the state of the driver. [Brief description of the drawings]

[0011] [Figure 1] FIG. 2 is a diagram showing the configuration and control block diagram of a tractor. [Diagram 2] FIG. 2 is an explanatory diagram for explaining automatic steering. [Figure 3A]FIG. 11 is an explanatory diagram for explaining a correction amount in a push switch. [Figure 3B] FIG. 11 is an explanatory diagram for explaining a correction amount in a slide switch. [Figure 4A] 4A and 4B are diagrams illustrating a first correction section and a second correction section in the push switch. [Figure 4B] 11 is a diagram showing a first correction unit and a second correction unit in the slide switch. FIG. [Figure 5A] This shows the state when the calculated vehicle body position is shifted to the right while driving straight under automatic steering. [Figure 5B] This shows the state when the calculated vehicle body position is shifted to the left while driving straight under automatic steering. [Figure 6] This is a view of the cover in front of the driver's seat as seen from the driver's seat side. [Figure 7] FIG. 2 is an explanatory diagram for explaining automatic steering. [Figure 8] FIG. [Figure 9] 4 is an operational flow showing the relationship between the seating state and automatic steering. [Figure 10] 11 is an explanatory diagram illustrating an elapsed time T1 in the absence detection state and a notification. FIG. [Figure 11] FIG. 13 is a diagram showing an operation flow for stopping manual steering as well. [Figure 12A] 4 is an operational flow showing the relationship between the speed doubling device and automatic steering. [Figure 12B] 4 is an operational flow showing the relationship between the auto-up device and automatic steering. [Figure 13] FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0013] Fig. 13 is a side view showing one embodiment of the work vehicle 1, and Fig. 13 is a plan view showing one embodiment of the work vehicle 1. In the case of this embodiment, the work vehicle 1 is a tractor. However, the work vehicle 1 is not limited to a tractor, and may be an agricultural machine (agricultural vehicle) such as a combine harvester or transplanter, or a construction machine (construction vehicle) such as a loader work machine.

[0014] In the following description, the front side of the driver seated in the driver's seat 10 of the tractor (work vehicle) 1 (the direction of the arrow A1 in FIG. 13) will be referred to as the front, the rear side of the driver (the direction of the arrow A2 in FIG. 13) as the rear, the left side of the driver as the left side, and the right side of the driver as the right side. In addition, the horizontal direction perpendicular to the front-to-rear direction of the work vehicle 1 will be referred to as the vehicle body width direction.

[0015] As shown in Fig. 13, the tractor 1 includes a vehicle body 3, a prime mover 4, and a transmission 5. The vehicle body 3 has a traveling device 7 and is capable of traveling. The traveling device 7 is a device having front wheels 7F and rear wheels 7R. The front wheels 7F may be of a tire type or a crawler type. The rear wheels 7R may also be of a tire type or a crawler type.

[0016] The prime mover 4 is a diesel engine, an electric motor, or the like, and in this embodiment is configured with a diesel engine. The transmission 5 is capable of switching the propulsive force of the traveling device 7 by shifting gears, and also capable of switching the traveling device 7 between forward and reverse. The vehicle body 3 is provided with a driver's seat 10.

[0017] In addition, a coupling section including a lifting device 8 is provided at the rear of the vehicle body 3. A working device can be attached and detached to the coupling section. By coupling the working device to the coupling section, the working device can be towed by the vehicle body 3. The working devices include a tilling device for tilling, a fertilizer spreading device for spreading fertilizer, a pesticide spreading device for spreading pesticide, a harvesting device for harvesting, a reaping device for reaping grass and the like, a spreading device for spreading grass and the like, a grass collecting device for collecting grass and the like, a shaping device for shaping grass and the like, and the like.

[0018] As shown in Fig. 1, the transmission 5 includes a main shaft (propeller shaft) 5a, a main speed change section 5b, an auxiliary speed change section 5c, a shuttle section 5d, a PTO power transmission section 5e, and a front speed change section 5f. The propeller shaft 5a is rotatably supported in a housing case (transmission case) of the transmission 5, and power is transmitted from the crankshaft of the engine 4 to the propeller shaft 5a. The main speed change section 5b has a plurality of gears and a shifter that changes the connection of the gears. The main speed change section 5b changes and outputs (changes the speed of) the rotation input from the propeller shaft 5a by appropriately changing the connection (meshing) of the plurality of gears with the shifter.

[0019] The sub-transmission unit 5c, like the main transmission unit 5b, has multiple gears and a shifter that changes the connection of the gears. The sub-transmission unit 5c changes and outputs (shifts) the rotation input from the main transmission unit 5b by appropriately changing the connection (meshing) of the multiple gears with the shifter.

[0020] The shuttle section 5d has a shuttle shaft 12 and a forward / reverse switching section 13. Power output from the sub-transmission section 5c is transmitted to the shuttle shaft 12 via gears or the like. The forward / reverse switching section 13 is composed of, for example, a hydraulic clutch, and switches the rotation direction of the shuttle shaft 12, i.e., the forward and reverse of the tractor 1, by engaging and disengaging the hydraulic clutch. The shuttle shaft 12 is connected to a rear wheel differential device 20R. The rear wheel differential device 20R rotatably supports a rear axle 21R to which the rear wheels 7R are attached.

[0021] The PTO power transmission section 5e has a PTO propulsion shaft 14 and a PTO clutch 15. The PTO propulsion shaft 14 is rotatably supported and is capable of transmitting power from the propulsion shaft 5a. The PTO propulsion shaft 14 is connected to a PTO shaft 16 via gears or the like. The PTO clutch 15 is composed of, for example, a hydraulic clutch, and switches between a state in which the power of the propulsion shaft 5a is transmitted to the PTO propulsion shaft 14 and a state in which the power of the propulsion shaft 5a is not transmitted to the PTO propulsion shaft 14 by switching the hydraulic clutch on and off.

[0022] The front transmission unit 5f has a first clutch 17 and a second clutch 18. The first clutch 17 and the second clutch can transmit power from the drive shaft 5a, for example, the power of the shuttle shaft 12 is transmitted via a gear and a transmission shaft. The power from the first clutch 17 and the second clutch 18 can be transmitted to the front axle 21F via a front transmission shaft 22. Specifically, the front transmission shaft 22 is connected to a front wheel differential device 20F, and the front wheel differential device 20F rotatably supports the front axle 21F to which the front wheels 7F are attached.

[0023] The first clutch 17 and the second clutch 18 are composed of a hydraulic clutch or the like. An oil passage is connected to the first clutch 17, and the oil passage is connected to a first operating valve 25 to which hydraulic oil discharged from a hydraulic pump is supplied. The first clutch 17 is switched between an engaged state and a disengaged state depending on the opening degree of the first operating valve 25. An oil passage is connected to the second clutch 18, and the oil passage is connected to a second operating valve 26. The second clutch 18 is switched between an engaged state and a disengaged state depending on the opening degree of the second operating valve 26. The first operating valve 25 and the second operating valve 26 are, for example, two-position switching valves with solenoid valves, and are switched between an engaged state and a disengaged state by energizing or deenergizing a solenoid of the solenoid valve.

[0024] When the first clutch 17 is in a disengaged state and the second clutch 18 is in an engaged state, the power of the shuttle shaft 12 is transmitted to the front wheels 7F through the second clutch 18. As a result, the front and rear wheels are driven by power in a four-wheel drive (4WD) state, and the rotation speeds of the front and rear wheels are approximately the same (4WD constant speed state). On the other hand, when the first clutch 17 is in an engaged state and the second clutch 18 is in a disengaged state, the vehicle is in four-wheel drive and the rotation speed of the front wheels is faster than the rotation speed of the rear wheels (4WD speed increase state). Also, when the first clutch 17 and the second clutch 18 are in a disengaged state, the power of the shuttle shaft 12 is not transmitted to the front wheels 7F, and the vehicle is in two-wheel drive (2WD) in which the rear wheels are driven by power.

[0025] As shown in Fig. 8, the lifting device 8 has a lift arm 8a, a lower link 8b, a top link 8c, a lift rod 8d, and a lift cylinder 8e. The front end of the lift arm 8a is supported on the upper rear part of a case (transmission case) that houses the transmission 5 so as to be able to swing upward or downward. The lift arm 8a swings (lifts and lowers) by driving the lift cylinder 8e. The lift cylinder 8e is composed of a hydraulic cylinder. The lift cylinder 8e is connected to a hydraulic pump via a control valve 29. The control valve 29 is an electromagnetic valve or the like, and extends and retracts the lift cylinder 8e.

[0026] A front end of the lower link 8b is supported on the rear lower part of the transmission 5 so as to be able to swing upward or downward. A front end of the top link 8c is supported on the rear part of the transmission 5 above the lower link 8b so as to be able to swing upward or downward. A lift rod 8d connects the lift arm 8a to the lower link 8b. A working device 2 is connected to the rear part of the lower link 8b and the rear part of the top link 8c. When the lift cylinder 8e is driven (extends and retracts), the lift arm 8a rises and lowers, and the lower link 8b connected to the lift arm 8a via the lift rod 8d rises and lowers. As a result, the working device 2 swings upward or downward (rises and falls) with the front part of the lower link 8b as a fulcrum.

[0027] The tractor 1 is equipped with a positioning device 40. The positioning device 40 is a D-GPS, GPS, G The position (positioning information including latitude and longitude) of the vehicle can be detected by a satellite positioning system (positioning satellite) such as LONASS, Hokuto, Galileo, and Michibiki. That is, the positioning device 40 receives a satellite signal (position of the positioning satellite, transmission time, correction information, etc.) transmitted from the positioning satellite, and detects the position (e.g., latitude and longitude) based on the satellite signal. The positioning device 40 has a receiving device 41 and an inertial measurement unit (IMU) 42. The receiving device 41 is a device that has an antenna and receives a satellite signal transmitted from the positioning satellite, and is attached to the vehicle body 3 separately from the inertial measurement unit 42. In this embodiment, the receiving device 41 is attached to a ROPS provided on the vehicle body 3. The mounting location of the receiving device 41 is not limited to the embodiment.

[0028] The inertial measurement unit 42 has an acceleration sensor that detects acceleration, a gyro sensor that detects angular velocity, etc. The inertial measurement unit 42 is provided on the vehicle body 3, for example, below the driver's seat 10, and can detect the roll angle, pitch angle, yaw angle, etc. of the vehicle body 3.

[0029] As shown in Fig. 1, the tractor 1 is equipped with a steering device 11. The steering device 11 is a device capable of performing manual steering, in which the vehicle body 3 is steered by the driver's operation, and automatic steering, in which the vehicle body 3 is steered automatically without the driver's operation.

[0030] The steering device 11 has a steering handle (steering wheel) 30 and a steering shaft (rotating shaft) 31 that rotatably supports the steering handle 30. The steering device 11 also has an assist mechanism (power steering device) 32. The assist mechanism 32 assists the rotation of the steering shaft 31 (steering handle 30) by hydraulic pressure or the like. The assist mechanism 32 includes a hydraulic pump 33, a control valve 34 to which hydraulic oil discharged from the hydraulic pump 33 is supplied, and a steering cylinder 35 operated by the control valve 34. The control valve 34 is, for example, a three-position switching valve that can be switched by movement of a spool or the like, and switches in accordance with the steering direction (rotation direction) of the steering shaft 31. The steering cylinder 35 is connected to an arm (knuckle arm) 36 that changes the direction of the front wheels 7F.

[0031] Therefore, when the driver grips the steering wheel 30 and turns it in one direction or the other, the switching position and opening of the control valve 34 are switched corresponding to the rotation direction of the steering wheel 30, and the steering cylinder 35 expands or contracts to the left or right according to the switching position and opening of the control valve 34, thereby changing the steering direction of the front wheels 7F. In other words, the traveling direction of the vehicle body 3 can be changed to the left or right by manually steering the steering wheel 30.

[0032] Next, automatic steering will be described.

[0033] As shown in Fig. 2, when performing automatic steering, first, a driving reference line L1 is set before performing automatic steering. After setting the driving reference line L1, automatic steering can be performed by setting a planned driving line L2 parallel to the driving reference line L1. In automatic steering, the tractor 1 (vehicle body 3) is automatically steered in the traveling direction so that the vehicle body position measured by the positioning device 40 coincides with the planned driving line L2.

[0034] Specifically, before performing automatic steering, the tractor 1 (body 3) is moved to a predetermined position in the field (S1), and when the driver operates the steering change-over switch 52 provided on the tractor 1 at the predetermined position (S2), the body position measured by the positioning device 40 is set to the start point P10 of the traveling reference line L1 (S3). In addition, the tractor 1 (body 3) is moved from the start point P10 of the traveling reference line L1 (S4), and when the driver operates the steering change-over switch 52 at the predetermined position (S5), the body position measured by the positioning device 40 is set to the end point P11 of the traveling reference line L1 (S6). Therefore, a straight line connecting the start point P10 and the end point P11 is set as the traveling reference line L1.

[0035] After the driving reference line L1 is set (after S6), for example, when the tractor 1 (body 3) is moved (S7) to a location different from the location where the driving reference line L1 was set, and the driver operates the steering changeover switch 52 (S8), a planned driving line L2, which is a straight line parallel to the driving reference line L1, is set (S9). After the planned driving line L2 is set, automatic steering is started, and the traveling direction of the tractor 1 (body 3) is changed so as to follow the planned driving line L2. For example, if the current When the vehicle body position is on the left side of the planned travel line L2, the front wheels 7F are steered to the right, and when the current vehicle body position is on the right side of the planned travel line L2, the front wheels 7F are steered to the left. Note that during automatic steering, the traveling speed (vehicle speed) of the tractor 1 (vehicle body 3) can be changed by the driver manually changing the amount of operation of an accelerator member (accelerator pedal, accelerator lever) provided on the tractor 1 or by changing the gear stage of the transmission.

[0036] Furthermore, after automatic steering has started, the driver can end the automatic steering by operating the steering changeover switch 52 at any point. That is, the end point of the planned travel line L2 can be set by ending automatic steering by operating the steering changeover switch 52. That is, the length from the start point to the end point of the planned travel line L2 can be set longer or shorter than the travel reference line L1. In other words, the planned travel line L2 is not associated with the length of the travel reference line L1, and the planned travel line L2 allows the vehicle to travel a distance longer than the length of the travel reference line L1 while undergoing automatic steering.

[0037] As shown in FIG. 1, the steering device 11 has an automatic steering mechanism 37. The automatic steering mechanism 37 is a mechanism that automatically steers the vehicle body 3, and automatically steers the vehicle body 3 based on the position of the vehicle body 3 (vehicle body position) detected by the positioning device 40. The automatic steering mechanism 37 includes a steering motor 38 and a gear mechanism 39. The steering motor 38 is a motor whose rotation direction, rotation speed, rotation angle, etc. can be controlled based on the vehicle body position. The gear mechanism 39 includes a gear provided on the steering shaft 31 and rotating together with the steering shaft 31, and a gear provided on the rotation shaft of the steering motor 38 and rotating together with the rotation shaft. When the rotation shaft of the steering motor 38 rotates, the steering shaft 31 automatically rotates (turns) via the gear mechanism 39, and the steering direction of the front wheels 7F can be changed so that the vehicle body position coincides with the planned travel line L2.

[0038] 1, the tractor 1 is equipped with a display device 45. The display device 45 is a device capable of displaying various information related to the tractor 1, and is capable of displaying at least driving information of the tractor 1. The display device 45 is provided in front of the driver's seat 10.

[0039] As shown in Fig. 1, the tractor 1 is provided with a setting switch 51. The setting switch 51 is a switch for switching to a setting mode in which at least settings before the start of automatic steering are performed. The setting mode is a mode in which various settings related to automatic steering are performed before the start of the automatic steering, for example, a mode in which the start point and end point of the driving reference line L1 are set.

[0040] The setting switch 51 can be switched between ON and OFF, and when it is ON it outputs a signal indicating that the setting mode is valid, and when it is OFF it outputs a signal indicating that the setting mode is invalid. Furthermore, when the setting switch 51 is ON it outputs a signal indicating that the setting mode is valid to the display device 45, and when it is OFF it outputs a signal indicating that the setting mode is invalid to the display device 45.

[0041] The tractor 1 is provided with a steering changeover switch 52. The steering changeover switch 52 is a switch for switching the start or end of automatic steering. Specifically, the steering changeover switch 52 can be switched from a neutral position to up, down, forward, or backward, and outputs the start of automatic steering when the steering changeover switch 52 is switched from the neutral position to down while the setting mode is active, and outputs the end of automatic steering when the steering changeover switch 52 is switched from the neutral position to up while the setting mode is active. In addition, when the steering changeover switch 52 is switched from the neutral position to backward while the setting mode is active, the steering changeover switch 52 outputs a command to set the current vehicle body position to the start point P10 of the driving reference line L1, and when the steering changeover switch 52 is switched from the neutral position to forward while the setting mode is active, the steering changeover switch 52 outputs a command to set the current vehicle body position to the end point P11 of the driving reference line L1. That is, the steering changeover switch 52 also serves as a reference line setting switch that sets the start position (start point P10) and end position (end point P11) of the driving reference line L1. Note that the steering changeover switch 52, which switches the start or end of automatic steering, may be configured separately from the reference line setting switch.

[0042] The tractor 1 is provided with a correction switch 53. The correction switch 53 is a switch for correcting the vehicle body position (latitude, longitude) measured by the positioning device 40. Switch 53 is a switch that corrects the vehicle position (called the calculated vehicle position) calculated using the satellite signals (position of the positioning satellite, transmission time, correction information, etc.) and the measurement information (acceleration, angular velocity) measured by the inertial measurement unit 42.

[0043] The correction switch 53 is configured as a push switch that can be pressed or a slide switch that can be slid. Below, the cases where the correction switch 53 is a push switch and a slide switch will be described.

[0044] When the correction switch 53 is a push switch, the amount of correction is set based on the number of times the push switch is operated. The amount of correction is determined by the formula: correction amount = number of times of operation x correction amount per one operation. For example, as shown in Fig. 3A, the amount of correction increases by several centimeters or several tens of centimeters each time the push switch is operated. The number of times the push switch is operated is input to the first control device 60A, which sets (calculates) the amount of correction based on the number of times the push switch is operated.

[0045] Furthermore, when the correction switch 53 is a slide switch, the correction amount is set based on the operation amount (displacement amount) of the slide switch. For example, the correction amount is determined by the correction amount=displacement amount from a predetermined position. For example, as shown in FIG. 3B, the correction amount increases by several centimeters or several tens of centimeters every time the displacement amount of the slide switch increases by 5 mm. The operation amount (displacement amount) of the slide switch is input to the first control device 60A, which sets (calculates) the correction amount based on the displacement amount. Note that the method of increasing the correction amount and the rate of increase are not limited to the above-mentioned numerical values.

[0046] 4A and 4B, the correction switch 53 has a first correction unit 53A and a second correction unit 53B. The first correction unit 53A is a unit that issues a command to correct the vehicle body position corresponding to one side in the width direction of the vehicle body 3, i.e., the left side. The second correction unit 53B is a unit that issues a command to correct the vehicle body position corresponding to the other side in the width direction of the vehicle body 3, i.e., the right side.

[0047] As shown in FIG. 4A, when the correction switch 53 is a push switch, the first correction unit 53A and the second correction unit 53B are ON or OFF switches that are automatically restored every time they are operated. The switch constituting the first correction unit 53A and the switch constituting the second correction unit 53B are integrated. The switch constituting the first correction unit 53A and the switch constituting the second correction unit 53B may be arranged apart from each other. As shown in FIG. 3A, every time the first correction unit 53A is pressed, the correction amount (left correction amount) corresponding to the left side of the vehicle body 3 increases. Also, every time the second correction unit 53B is pressed, the correction amount (right correction amount) corresponding to the right side of the vehicle body 3 increases.

[0048] As shown in FIG. 4B, when the correction switch 53 is a slide switch, the first correction unit 53A and the second correction unit 53B include a knob 55 that moves left or right along the longitudinal direction of the long hole. When the correction switch 53 is a slide switch, the first correction unit 53A and the second correction unit 53B are arranged spaced apart from each other in the width direction. As shown in FIG. 3B, when the knob 55 is gradually displaced leftward from a predetermined reference position, the left correction amount increases according to the amount of displacement. Also, when the knob 55 is gradually displaced rightward from a predetermined reference position, the right correction amount increases according to the amount of displacement. Note that, as shown in FIG. 4B, when the correction switch 53 is a slide switch, the first correction unit 53A and the second correction unit 53B may be integrally formed, the reference position of the knob 55 is set to the center, and when the knob 55 is moved leftward from the reference position, the left correction amount is set, and when the knob 55 is moved rightward from the middle position, the right correction amount is set.

[0049] Next, the relationship between the correction amount (left correction amount, right correction amount) by the correction switch 53, the intended travel line L2, and the behavior (travel trajectory) of the tractor 1 (vehicle body 3) will be described.

[0050] 5A shows a state in which the calculated vehicle body position W1 is shifted to the right while traveling straight under automatic steering. As shown in FIG. 5A, when automatic steering is started, if the actual position (actual position W2) of the tractor 1 (vehicle body 3) coincides with the calculated vehicle body position W1 and the actual position W2 coincides with the planned traveling line L2, the tractor 1 travels along the planned traveling line L2. That is, in the section P1 where there is no error in the positioning of the positioning device 40 and the vehicle body position (calculated vehicle body position W1) detected by the positioning device 40 is the same as the actual position W2, the tractor 1 travels along the planned traveling line L2. 2. When there is no error in the positioning by the positioning device 40 and no correction is performed, the calculated vehicle body position W1 and the vehicle body position after correction with the correction amount (corrected vehicle body position) W3 are the same value. The corrected vehicle body position W3 is calculated vehicle body position W3 = calculated vehicle body position W1 - correction amount.

[0051] Here, in the vicinity of position P20, even though the actual position W2 is not deviated from the planned travel line L2, an error occurs in the positioning of the positioning device 40 due to various influences, and the vehicle body position W1 detected by the positioning device 40 deviates to the right from the planned travel line L2 (actual position W2), and if the deviation amount W4 is maintained, the tractor 1 determines that a deviation has occurred between the calculated vehicle body position W1 and the planned travel line L2, and steers the tractor 1 to the left so as to eliminate the deviation amount W4 between the calculated vehicle body position W1 and the planned travel line L2. Then, the actual position W2 of the tractor 1 is shifted to the planned travel line L2 by steering to the left. After that, it is assumed that the driver notices that the tractor 1 is deviated from the planned travel line L2, and steers the second correction unit 53B at position P21 to increase the right correction amount from zero. A right correction amount is added to the calculated vehicle body position W1, and the corrected vehicle body position (corrected vehicle body position) W3 can be made substantially the same as the actual position W2. In other words, by setting the right correction amount by the second correction unit 53B, the vehicle body position of the positioning device 40 can be corrected in a direction that eliminates the deviation amount W4 that occurs near the position P20. Note that, as shown in position P21 in FIG. 5A, if the actual position W2 of the tractor 1 is away from the planned travel line L2 to the left after the vehicle body position is corrected, the tractor 1 is steered to the right, and the actual position W2 of the tractor 1 can be made to coincide with the planned travel line L2.

[0052] Fig. 5B shows a state in which the calculated vehicle body position W1 is shifted to the left while traveling straight under automatic steering. As shown in Fig. 5B, when automatic steering is started, if the actual position W2 and the calculated vehicle body position W1 coincide with each other and the actual position W2 and the planned travel line L2 coincide with each other, the tractor 1 travels along the planned travel line L2, as in Fig. 5A. That is, as in Fig. 5A, in the section P2 where there is no error in the positioning of the positioning device 40, the tractor 1 travels along the planned travel line L2. Also, as in Fig. 5A, the calculated vehicle body position W1 and the corrected vehicle body position W3 are the same value.

[0053] Here, if an error occurs in the positioning of the positioning device 40 due to various influences at the position P22, and the vehicle body position W1 detected by the positioning device 40 is shifted to the left with respect to the actual position W2, and the shift amount W5 is maintained, the tractor 1 steers the tractor 1 to the right so as to eliminate the shift amount W5 between the calculated vehicle body position W1 and the planned travel line L2. Then, suppose that the driver notices that the tractor 1 is shifted from the planned travel line L2, and steers the first correction unit 53A at the position P23 to increase the left correction amount from zero. Then, the left correction amount is added to the calculated vehicle body position W1, and the corrected vehicle body position (corrected vehicle body position) W3 can be made substantially the same as the actual position W2. In other words, by setting the left correction amount by the first correction unit 53A, the vehicle body position of the positioning device 40 can be corrected in a direction that eliminates the shift amount W5 that occurred near the position P22. In addition, as shown in position P23 in Figure 5B, if, after correcting the vehicle position, the actual position W2 of the tractor 1 is away to the right of the planned driving line L2, the tractor 1 is steered to the left, and the actual position W2 of the tractor 1 can be aligned with the planned driving line L2.

[0054] Next, the setting switch 51 and the correction switch 53 will be described.

[0055] 6, the outer periphery of the steering shaft 31 is covered by a steering post 180. The outer periphery of the steering post 180 is covered by a cover 177. The cover 177 is provided in front of the driver's seat 10. The cover 177 includes a panel cover 178 and a column cover 179.

[0056] The panel cover 178 supports the display device 45. The upper plate portion 178a of the panel cover 178 is provided with a support portion 178e that supports the display device 45. The support portion 178e supports the display device 45 in front of the steering shaft 31 and below the steering handle 30. The upper plate portion 178a also has an attachment surface 178f to which the setting switch 51 and the correction switch 53 are attached. The attachment surface 178f is provided behind the support portion 178e and below the steering handle 30. The support portion 178e and the attachment surface 178f are continuous with each other, the support portion 178e being located in front of the upper plate portion 178a, and the attachment surface 178f being located in the rear of the upper plate portion 178a. The setting switch 51 and the correction switch 53 are attached to the attachment surface 178f. As a result, the setting switch 51 and the correction switch 53 are arranged around the steering shaft 31.

[0057] A shuttle lever 181 protrudes from the left plate portion 178b of the panel cover 178. The shuttle lever 181 is a member that switches the traveling direction of the vehicle body 3. To explain in more detail, by operating (swinging) the shuttle lever 181 forward, the forward / reverse switching unit 13 is placed in a state in which it outputs forward power to the traveling device 7, and the traveling direction of the vehicle body 3 is switched to the forward direction. In addition, by operating (swinging) the shuttle lever 181 backward, the forward / reverse switching unit 13 is placed in a state in which it outputs reverse power to the traveling device 7, and the traveling direction of the vehicle body 3 is switched to the reverse direction. When the shuttle lever 181 is in the neutral position, no power is output to the traveling device 7.

[0058] The column cover 179 is disposed below the steering wheel 30, and covers the periphery of the upper part of the steering shaft 31. The column cover 179 is formed in a substantially rectangular tubular shape, and protrudes upward from the mounting surface 178f of the panel cover 178. In other words, the mounting surface 178f is provided around the column cover 179. Therefore, the setting switch 51 and the correction switch 53 attached to the mounting surface 178f are disposed around the column cover 179.

[0059] Next, a detailed description will be given of the locations of the setting switch 51, the steering changeover switch 52, and the correction switch 53. As shown in FIG.

[0060] The setting switch 51 is disposed on one side (left side) of the steering shaft 31. The steering changeover switch 52 is disposed on one side (left side) of the steering shaft 31. In this embodiment, the steering changeover switch 52 is composed of a swingable lever. The steering changeover switch 52 can swing around a base end provided on the steering shaft 31 side as a fulcrum. The base end of the steering changeover switch 52 is provided inside the column cover 179. The steering changeover switch 52 protrudes from one side (left side) of the column cover 179.

[0061] The correction switch 53 is disposed on the other side (right side) of the steering shaft 31. More specifically, the correction switch 53 is disposed on the right side and rear (diagonally rear right) of the steering shaft 31. In terms of its positional relationship with the column cover 179, the correction switch 53 is disposed on the right side and rear (diagonally rear right) of the column cover 179. In terms of its positional relationship with the mounting surface 178f of the panel cover 178, the correction switch 53 is disposed on the right rear part of the mounting surface 178f. By disposing the correction switch 53 on the rear part of the inclined mounting surface 178f, it is possible to ensure a long distance between the correction switch 53 and the steering wheel 30. This makes it possible to more reliably prevent unintentional operation of the correction switch 53 and steering of the steering wheel 30.

[0062] As described above, the setting switch 51, the steering changeover switch 52, and the correction switch 53 are arranged around the steering shaft 31. In other words, the setting switch 51, the steering changeover switch 52, and the correction switch 53 are concentrated around the steering shaft 31. Therefore, the driver can clearly understand the position of each switch at a glance. In addition, the driver can operate each switch without changing his / her posture while remaining seated in the driver's seat 10. This improves operability and prevents erroneous operation. Also, the harness (wiring) routed from each switch can be shortened.

[0063] Incidentally, the above-mentioned switches may be arranged with the left and right interchanged. That is, one side may be the left and the other side may be the right, or one side may be the right and the other side may be the left. Specifically, for example, the setting switch 51 and the steering changeover switch 52 may be arranged on the right side of the steering shaft 31, and the correction switch 53 may be arranged on the left side of the steering shaft 31.

[0064] As shown in Fig. 1, the tractor 1 is equipped with a plurality of control devices 60. The plurality of control devices 60 are devices that control the travel system, the work system, calculate the vehicle body position, and the like in the tractor 1. The plurality of control devices 60 are a first control device 60A, a second control device 60B, and a third control device 60C.

[0065] The first control device 60A receives the satellite signal (received information) received by the receiving device 41 and the measurement information (acceleration, angular velocity, etc.) measured by the inertial measurement device 42, and determines the vehicle body position based on the received information and the measurement information. For example, when the correction amount by the correction switch 53 is zero, that is, when the correction of the vehicle body position by the correction switch 53 is not commanded, the first control device 60A does not correct the calculated vehicle body position W1 calculated from the received information and the measurement information, and determines the calculated vehicle body position W1 as the vehicle body position to be used during automatic steering. On the other hand, when the correction of the vehicle body position by the correction switch 53 is commanded, the first control device 60A sets the correction amount of the vehicle body position based on either the number of times the correction switch 53 is operated or the operation amount (displacement amount) of the correction switch 53, and determines the corrected vehicle body position W3 obtained by correcting the calculated vehicle body position W1 with the correction amount as the vehicle body position to be used during automatic steering.

[0066] The first control device 60A sets a control signal based on the vehicle body position (calculated vehicle body position W1, corrected vehicle body position W3) and the intended travel line L2, and outputs the control signal to the second control device 60B. The second control device 60B has an automatic steering control unit 200. The automatic steering control unit 200 is composed of electric and electronic circuits provided in the second control device 60B, programs stored in a CPU, etc. The automatic steering control unit 200 controls the steering motor 38 of the automatic steering mechanism 37 based on the control signal output from the first control device 60A so that the vehicle body 3 travels along the intended travel line L2.

[0067] As shown in Fig. 7, when the deviation between the vehicle body position and the planned travel line L2 is less than the threshold, the automatic steering control unit 200 maintains the rotation angle of the rotation shaft of the steering motor 38. When the deviation between the vehicle body position and the planned travel line L2 is equal to or greater than the threshold and the tractor 1 is located on the left side of the planned travel line L2, the automatic steering control unit 200 rotates the rotation shaft of the steering motor 38 so that the steering direction of the tractor 1 becomes the right direction. When the deviation between the vehicle body position and the planned travel line L2 is equal to or greater than the threshold and the tractor 1 is located on the right side of the planned travel line L2, the automatic steering control unit 200 rotates the rotation shaft of the steering motor 38 so that the steering direction of the tractor 1 becomes the left direction. In the above-described embodiment, the steering angle of the steering device 11 is changed based on the deviation between the vehicle body position and the planned travel line L2. However, when the orientation of the planned travel line L2 and the orientation (vehicle body orientation) F1 of the traveling direction (traveling direction) of the tractor 1 (vehicle body 3) are different, that is, when the angle θg of the vehicle body orientation F1 with respect to the planned travel line L2 is equal to or greater than a threshold value, the automatic steering control unit 200 may set the steering angle so that the angle θg is zero (the vehicle body orientation F1 matches the orientation of the planned travel line L2). The automatic steering control unit 200 may also set the final steering angle in automatic steering based on the steering angle calculated based on the deviation (position deviation) and the steering angle calculated based on the orientation (orientation deviation). The setting of the steering angle in automatic steering in the above-described embodiment is an example and is not limited.

[0068] As described above, the control device 60 can automatically steer the tractor 1 (vehicle body 3).

[0069] The third control device 60C performs various controls related to the tractor 1. The third control device 60C can perform manual lift control, auto-up control, double speed control, and the like. In the manual lift control, the lift device 8 is raised and lowered based on the operation of the lift switch 101 connected to the third control device 60C. Specifically, the lift switch 101 is provided around the driver's seat 10 and is a three-position switch. When the lift switch 101 is switched from the neutral position to one side, an up signal for raising the lift device 8 (lift arm 8a) is input to the third control device 60C. Also, when the lift switch 101 is switched from the neutral position to the other side, a down signal for lowering the lift device 8 (lift arm 8a) is input to the third control device 60C. When the third control device 60C receives an up signal, it outputs a control signal to the control valve 29 to raise the lift device 8, and when it receives a down signal, it outputs a control signal to the control valve 29 to lower the lift device 8. That is, the third control device 60 can perform manual lift control for lifting and lowering the lift device 8 in response to manual operation of the lift switch 101 .

[0070] In addition, the auto-up control is a control in which the lifting device 8 is automatically operated to raise the working device 2 when the tractor 1 (body 3) moves backward. Specifically, a reverse detector 102 that detects reverse movement is connected to the control device 60 such as the control device 60C. The reverse detector 102 is a sensor that detects the rotation of the front axle 21F, a sensor that detects the rotation of the rear axle 21R, a sensor that detects the switching position of the shuttle lever 181, and the like. That is, the reverse detector 102 detects the reverse movement of the tractor 1 (body 3) when the rotation direction of the front axle 21F and the rotation direction of the rear axle 21R are the rotation direction corresponding to reverse movement, and when the switching position of the shuttle lever 181 is on the reverse side. When the reverse detector 102 detects the reverse movement of the tractor 1 (body 3), the third control device 60C performs auto-up control to automatically raise the lifting device 8 by outputting a control signal to the control valve 29. Note that the reverse detector 102 described above is an example and is not limited.

[0071] In the double speed control, when the steering angle of the steering device 11 is equal to or greater than a predetermined value, for example, a steering angle corresponding to a turn, the connection of the first clutch 17 and the second clutch 18 is automatically changed to make the rotation speed of the front wheels 7F faster than the rotation speed of the rear wheels. Specifically, a steering angle detection device 205 that detects the steering angle of the steering device 11 is connected to a control device 60 such as the control device 60C. When the steering angle detected by the steering angle detection device 205 is equal to or greater than a steering angle corresponding to a turn, the control device 60C outputs control signals to the first operating valve 25 and the second operating valve 26 to connect the first clutch 17 and disconnect the second clutch 18, thereby making the rotation speed of the front wheels 7F faster than the rotation speed of the rear wheels.

[0072] As described above, the control device 60C can perform controls related to the tractor 1, such as manual lift control, auto-up control, and double speed control.

[0073] As described above, automatic steering can be performed by switching the steering changeover switch 52, but the tractor 1 changes the control related to the automatic steering depending on the seating situation of the operator (driver) in the driver's seat 10.

[0074] A seating detection device 110 is connected to the control device 60 such as the control device 60B. The seating detection device 110 is a device capable of detecting that the driver is seated in the driver's seat 10. The seating detection device 110 is, for example, a load sensor provided in the seat portion 10a or the backrest portion 10b of the driver's seat 10. When the seating detection device 110 is a load sensor provided in the seat portion 10a, if the load applied to the seat portion 10a is equal to or greater than a predetermined value (above a threshold value), the control device 60 determines that the driver is seated in the driver's seat 10, whereas if the load applied to the seat portion 10a is less than the threshold value, the control device 60 determines that the driver is not seated in the driver's seat 10.

[0075] Alternatively, even when the seating detection device 110 is a load sensor provided in the backrest 10b, if the load applied to the backrest 10b is equal to or greater than a predetermined value (above a threshold value), the control device 60B determines that the driver is seated in the driver's seat 10, whereas if the load applied to the backrest 10b is less than the threshold value, it determines that the driver is not seated in the driver's seat 10. In the above-described embodiment, the seating detection device 110 is configured with a load sensor, but is not limited thereto and may be any device capable of detecting seating in the driver's seat 10.

[0076] FIG. 9 is an operation flow showing the relationship between the seating state and automatic steering.

[0077] When the setting mode is enabled by the setting switch 51 in a situation where the start position (start point P10) and the end position (end point P11) are not set (S21, Yes), the second control device 60B monitors the detection status of the seating detection device 110. When the seating detection device 110 detects a person sitting (S22, Yes) and the steering changeover switch 52 is operated to set the start point (operation from the neutral position to the rearward) (S23, Yes), the current vehicle body position is set to the start point P10 of the driving reference line L1 (S24: start point registration). Note that the second control device 60B does not set the start point P10 even if the start point is operated in a situation where the seating detection device 110 does not detect a person sitting. When the driver is not sitting in the driver's seat 10 at the time of registering the start point, the display device 45 displays a message encouraging the driver to sit down.

[0078] In addition, when the seating detection device 110 detects a seated person (S22, Yes) and the steering changeover switch 52 is operated to the end point (operated from the neutral position to the forward position) (S2 5, Yes), and sets the current vehicle body position as the end point P11 of the driving reference line L1 (S26: End point registration). Note that the second control device 60B does not set the end point P11 even if the end point operation is performed when the seating detection device 110 does not detect a driver being seated. Also, when the driver is not seated in the driver's seat 10 at the time of registering the end point, the display device 45 displays a message encouraging the driver to sit down.

[0079] Therefore, while the driver is seated in the driver's seat 10, the start point P10 and the end point 11 of the driving reference line L1 can be set.

[0080] After setting the start point P10 and end point P11 of the driving reference line L1, when the steering changeover switch 52 switches to start automatic steering (S27, Yes), the second control device 60B judges whether the seating detection device 110 detects a seated person or not, and if a seated person is detected (S28, Yes), permits automatic steering (S29). When automatic steering is permitted, the second control device 60B sets the planned driving line L2 parallel to the driving reference line L1, and executes automatic steering as described above (S30).

[0081] On the other hand, when the seating detection device 110 does not detect a person being seated (S28, No), the second control device 60B does not permit automatic steering, that is, does not permit automatic steering even if the steering changeover switch 52 switches to start automatic steering (S31). When automatic steering is not permitted, the display device 45 displays a message encouraging the person to be seated.

[0082] The second control device 60B monitors the detection status of the seating detection device 110 even during automatic steering (S32). If, during automatic steering, the seating detection device 110 changes from a seating detection state in which it detects a person sitting to a leaving detection state in which it does not detect a person sitting (S33, Yes), the second control device 60B stops (ends) the automatic steering (S34: automatic steering stop). When automatic steering is stopped, the second control device 60B switches from automatic steering to manual steering, for example, by stopping the output of a control signal to the steering motor 38.

[0083] In addition, when the seat detection state is changed from the seat detection state to the absence detection state, the second control device 60B may stop the automatic steering when the elapsed time of the absence detection state (the elapsed time from the end of the seat detection state) T1 exceeds a predetermined threshold (determination time) as shown in FIG. 10. In this case, when the absence state is entered, it is preferable to notify the driver that the driver has left the driver's seat 10 by the notification device 80. Specifically, the notification device 80 is connected to the control device 60 such as the second control device 60B. The notification device 80 is a speaker, a lamp, or the like, and is provided near the driver's seat 10. As shown in FIG. 10, the notification device 80 starts notification (ON) at the time point P25 when the absence state is entered, and notifies the driver that the driver has left the driver's seat 10 by a voice output from a speaker, a warning sound, lighting or blinking of a lamp, or the like. As the time that has elapsed since the person left the desk increases, the alarm device 80 increases the time for which the voice and warning sound are output, decreases the flashing rate of the lamp, increases the brightness of the lamp, and increases the intensity of the alarm.

[0084] According to the above, the second control device 60B permits automatic steering when the seating detection device 110 detects a person seated and the start of automatic steering has been switched on by the steering changeover switch 52, and does not permit automatic steering when the seating detection device 110 does not detect a person seated and the start of automatic steering has been switched on by the steering changeover switch 52. Therefore, automatic steering can be started by operating the steering changeover switch 52 with the driver reliably seated in the driver's seat 10.

[0085] When automatic steering is being performed, if the seating detection device 110 changes from a seating detection state in which the seating is detected to a leaving detection state in which the seating is not detected, the second control device 60B stops (ends) the automatic steering. Therefore, the automatic steering can be stopped at the point when the driver leaves the driver's seat 10 during automatic steering.

[0086] In the above embodiment, the second control device 60B stops automatic steering when the seat detection state changes from the seated state to the unseated state, but in addition to this, manual steering may also be stopped. Figure 11 shows an operation flow for stopping manual steering as well. In Figure 11, S21 to S33 are the same as Figure 9.

[0087] As shown in FIG. 11, the second control device 60B changes from a seated detection state to an unseated detection state. If so (S33, Yes), the driving of the prime mover 4 is stopped (S35: stop prime mover). That is, the second control device 60B stops the prime mover 4 by turning off the ignition or outputting a signal to stop the driving of the prime mover 4 to a control device that controls the driving of the prime mover 4. When the prime mover 4 is stopped, power from the prime mover 4 is no longer transmitted to the traveling device 7, so that the tractor 1 (body 3) can be stopped.

[0088] The work vehicle 1 includes a driver's seat 10, a steering wheel 30, a vehicle body 3 capable of traveling by either manual steering using the steering wheel 30 or automatic steering of the steering wheel 30 based on a traveling reference line, a steering changeover switch 52 for switching between starting and ending automatic steering, a seating detection device 110 for detecting that the driver is seated in the driver's seat 10, and a control device 60 (second control device 60B) for permitting automatic steering when the seating detection device 110 detects that the driver is seated and the start of automatic steering is switched by the steering changeover switch 52, and for not permitting automatic steering when the seating detection device 110 does not detect that the driver is seated and the start of automatic steering is switched by the steering changeover switch 52. According to this, when the driver operates the steering changeover switch 52 to switch the start of automatic steering under a condition in which the driver is securely seated in the driver's seat 10, automatic steering can be started. That is, automatic steering can be performed appropriately according to the driver's state.

[0089] The control device 60 (second control device 60B) stops the automatic steering when the seating detection device 110 changes from a seating detection state in which the seating is detected to a leaving detection state in which the seating is not detected during automatic steering. This makes it possible to automatically switch from automatic steering to manual steering if the driver leaves the driver's seat 10 during automatic steering.

[0090] The work vehicle 1 includes a prime mover 4 provided on a vehicle body 3, and a traveling device 7 that drives the vehicle body 3 using the power of the prime mover 4, and the control device 60 (second control device 60B) stops driving the prime mover 4 when a state changes from a seated detection state to a seat-abandoned detection state. With this, when the driver leaves the driver's seat 10, both the automatic steering and the manual steering can be stopped, and the work vehicle 1 can also be stopped.

[0091] The work vehicle 1 is equipped with a positioning device 40 capable of detecting the position of the vehicle body 3, and a reference line setting switch that sets the position of the vehicle body 3 detected by the positioning device 40 as the start position and end position of the traveling reference line L1. This makes it possible to easily set the start position and end position of the traveling reference line L1 by operating the reference line setting switch.

[0092] The work vehicle 1 is equipped with a correction switch 53 that issues a command to correct the position of the vehicle body 3 detected by the positioning device 40, and a steering device 11 that steers the vehicle body 3 based on a corrected vehicle body position (corrected position) W3, which is the position of the vehicle body 3 corrected by operating the correction switch 53, and an intended travel line L2 that is set based on a travel reference line L1. This makes it possible to make the vehicle body 3 travel along the intended travel line L2 by the steering device 11 while correcting the position of the vehicle body 3 by operating the correction switch 53.

[0093] Now, in a state where automatic steering is being performed under the control of the second control device 60B, the third control device 60C of the tractor 1 can limit the operation of the operating device provided in the tractor 1. In other words, when automatic steering is being performed under the control of the second control device 60B, the third control device 60C limits the control of auto-up control, double speed control, etc.

[0094] The third control device 60C activates the actuator when predetermined operating conditions for the operation of the actuator are met when automatic steering is not performed (manual steering is performed), but does not activate the actuator when the operating conditions are met when automatic steering is performed.

[0095] The restrictions on the operation of the actuator will be described in detail below.

[0096] The operating device is, for example, a speed doubling device or an auto-up device. The speed doubling device is a device that makes the rotational speed of the front wheels 7F faster than the rotational speed of the rear wheels 7R by speed doubling control in the third control device 60C, with the steering angle of the steering wheel 30 being equal to or greater than a predetermined value (equal to or greater than the steering angle corresponding to turning). In this embodiment, the speed doubling device includes a first clutch 17, a second clutch 18, a first operating valve 25, and a second operating valve 26.

[0097] The auto-up device is a device that raises the lifting device 8 when the vehicle body 3 moves backward. In this embodiment, the auto-up device includes a lift cylinder 8e and a control valve 29.

[0098] Fig. 12A is an operation flow showing the relationship between the speed doubling device and automatic steering when the operating device is the speed doubling device. Note that the tractor 1 is provided with a changeover switch that switches the speed doubling control between enabled and disabled, and the operation flow of Fig. 12A will be described on the assumption that the speed doubling control is enabled by the changeover switch.

[0099] After setting the start position (start point P10) and end position (end point P11) of the driving reference line L1, in a state where automatic steering is not performed, that is, in a state where the start of automatic steering is not commanded by the steering changeover switch 52 (S40, No), the second control device 60B outputs stop information indicating that automatic steering is stopped to the third control device 60C (S41). On the other hand, when the third control device 60C acquires the stop information (S42), it monitors the steering angle detected by the steering angle detection device 205 (S43). When the steering angle detected by the steering angle detection device 205 is equal to or greater than a predetermined value (S44, Yes), the third control device 60C outputs a control signal to the first actuated valve 25 and the second actuated valve 26 to make the rotation speed of the front wheel 7F faster than the rotation speed of the rear wheel 7R (S45).

[0100] In addition, when the steering changeover switch 52 issues a command to start automatic steering (S40, Yes), the second control device 60B outputs operation information indicating that automatic steering is being operated to the third control device 60C (S46). When the third control device 60C acquires the operation information (S47), it sets the double speed control from enabled to disabled (S48), and does not perform the double speed control even if the steering angle detected by the steering angle detection device 205 is equal to or greater than a predetermined value. In addition, the third control device 60C waits until it acquires stop information indicating that automatic steering has been stopped (ended) from the second control device 60B (S49).

[0101] Next, when the steering changeover switch 52 commands the end of automatic steering (S50), the second control device 60B outputs stop information to the third control device 60C (S51). When the third control device 60C acquires the stop information (S49, Yes), it switches the double speed control from disabled to enabled (S52), returns to S43, and executes the double speed control.

[0102] In other words, the third control device 60C starts operation of the speed multiplier when automatic steering is not performed and the operating conditions are met, and does not start operation of the speed multiplier when automatic steering is performed and the operating conditions are met.

[0103] Fig. 12B is an operation flow showing the relationship between the auto-up device and automatic steering when the operating device is the auto-up device. Note that the tractor 1 is provided with a changeover switch that switches the auto-up control between enabled and disabled, and the operation flow of Fig. 12B will be described on the assumption that the auto-up control is enabled by the changeover switch.

[0104] After setting the start position (start point P10) and end position (end point P11) of the travel reference line L1, in a state where automatic steering is not being performed, i.e., in a state where the start of automatic steering is not commanded by the steering changeover switch 52 (S60, No), the second control device 60B outputs stop information to the third control device 60C (S61). On the other hand, when the third control device 60C acquires the stop information (S62), it determines whether the vehicle body 3 is moving backwards or not based on the detection information by the reverse movement detection device 102, and if the vehicle body 3 is moving backwards (S63, Yes), it outputs a control signal to the control valve 29 to automatically raise and lower the lifting device 8 (S64).

[0105] Furthermore, in a state where the start of automatic steering is commanded by the steering changeover switch 52 (S60, Yes), the second control device 60B outputs operation information to the third control device 60C (S65). When the third control device 60C acquires the operation information (S66), it sets the auto-up control from enabled to disabled (S67), and does not perform the auto-up control even if the reverse movement detection device 102 detects reverse movement. Furthermore, the third control device 60C waits until it acquires stop information transmitted from the second control device 60B (S68).

[0106] Next, when the steering changeover switch 52 commands the end of automatic steering (S69), the second control device 60B outputs stop information to the third control device 60C (S70). When the third control device 60C acquires the stop information (S68, Yes), it switches the double speed control from disabled to enabled (S71), returns to S63, and executes the auto-up control.

[0107] In other words, the third control device 60C starts operation of the auto-up device when automatic steering is not being performed and the operating conditions are met, and does not start operation of the auto-up device when automatic steering is being performed and the operating conditions are met.

[0108] The work vehicle 1 is equipped with a steering wheel 30, a vehicle body 3 capable of traveling by either manual steering using the steering wheel 30 or automatic steering of the steering wheel 30 based on a traveling reference line L1, an actuation device provided on the vehicle body 3, and a control device 60 (third control device 60C) that limits the actuation of the actuation device when automatic steering is being performed. With this, the actuation of the actuation device can be limited when automatic steering is performed, so that the effect of the actuation device on the automatic steering can be reduced, and automatic steering can be performed smoothly.

[0109] The control device 60 (third control device 60C) operates the operating device when predetermined operating conditions for the operation of the operating device are satisfied when automatic steering is not being performed, and does not operate the operating device when the operating conditions are satisfied when automatic steering is being performed. This allows automatic steering to be performed with priority over the operation of the operating device when the operating conditions are satisfied.

[0110] The work vehicle 1 is equipped with a travel device including front and rear wheels, and the operating device is a speed-doubling device that makes the rotational speed of the front wheels faster than the rotational speed of the rear wheels when the steering angle of the steering wheel 30 is equal to or greater than a predetermined value, and the control device 60 (third control device 60C) starts operation of the speed-doubling device when the operating condition is satisfied in a state where automatic steering is not performed, and does not start operation of the speed-doubling device when the operating condition is satisfied in a state where automatic steering is performed. According to this, when automatic steering is performed, the steering angle can be set to a predetermined value or more at which the speed-doubling device operates, and even when a speed-doubling device is present, automatic steering with higher accuracy can be performed.

[0111] The work vehicle 1 is equipped with a working device provided at the rear of the vehicle body 3, and a lifting device for raising and lowering the working device, and the operating device is an auto-up device that raises the lifting device when the vehicle body 3 moves in reverse, and the control device 60 (third control device 60C) starts the operation of the auto-up device when the operating condition is satisfied in a state where automatic steering is not performed, and does not start the operation of the auto-up device when the operating condition is satisfied in a state where automatic steering is performed. This allows automatic steering to be performed not only when the vehicle body 3 moves forward, but also when the vehicle body 3 moves in reverse.

[0112] The embodiments disclosed herein should be considered to be illustrative and not restrictive in all respects. The scope of the present invention is defined by the claims, not the above description, and is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0113] 1 Work vehicle 3. Body 4. Prime Mover 10 Driver's seat 11 Steering gear 30 Steering wheel 40 Positioning device 52 Steering switch 53 Correction Switch 60 Control device 60B Second control device 60C Third control device 101 Lift switch 102 Reverse detection device 110 Sitting detection device 205 Steering angle detection device L1 Driving reference line L2 Planned running line

Claims

1. The driver's seat and A steering handle and A vehicle body capable of traveling by either manual steering using the steering wheel or automatic steering of the steering wheel that steers the traveling direction so as to coincide with a planned traveling line that is parallel to a traveling reference line; A prime mover provided on the vehicle body; a traveling device that causes the vehicle body to travel using the power of the prime mover; A positioning device capable of detecting the position of the vehicle body; a reference line setting switch for setting the vehicle body position detected by the positioning device to the start position and end position of the travel reference line; a steering changeover switch for changing over between the automatic steering and the manual steering; A seating detection device for detecting a driver being seated; a control device that permits the automatic steering when the seating detection device detects the seating and when a switching operation from manual steering to automatic steering is performed by the steering changeover switch; An alarm device that notifies the driver that the driver is away from the driver's seat; Equipped with The control device of this work vehicle, when the automatic steering is being performed and the seating detection device changes from a seating detection state in which the seating is detected to an absence detection state in which the seating is not detected, issues the alert via the alarm device, and stops the automatic steering and the travel of the vehicle body when the progression of the absence detection state exceeds a predetermined judgment threshold.

2. The work vehicle according to claim 1 , wherein the notification device increases a notification intensity as the time period during which the absence from the seat is detected increases.

Images