Work vehicles

Abstract

This enables the vehicle to travel along its planned route even if there are positioning errors (positioning accuracy) from the positioning device. [Solution] The work vehicle comprises a vehicle body, a coupling section, a steering wheel, a positioning device for detecting the vehicle body position, the vehicle body position detected by the positioning device, an automatic steering mechanism, a display device capable of displaying the deviation between the vehicle body position detected by the positioning device and the planned driving line, and a correction switch for setting a correction amount. The automatic steering mechanism is capable of automatic steering based on the deviation changed by the correction amount set by the correction switch, and the display device displays a screen for changing the correction amount of the operation unit of the correction switch.

Description

Technical Field

[0001] The present invention relates to a work vehicle such as a tractor, for example.

Background Art

[0002] Conventionally, Patent Document 1 is known as an agricultural work machine. The agricultural work machine of Patent Document 1 includes a traveling body capable of switching between manual traveling by manual steering and automatic traveling along a set traveling line set parallel to a reference traveling line, and a switching switch capable of switching between manual traveling and automatic traveling.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the agricultural work machine of Patent Document 1, since the position of the machine body is detected by GPS or the like to set a reference traveling line, a set traveling line, etc., the fact is that the influence of the positioning of the position such as GPS cannot be reduced in the steering, traveling, etc. of the machine body.

[0005] Therefore, in view of the above problems, an object of the present invention is to provide a work vehicle capable of traveling the vehicle body along a planned traveling line even under the influence of a positioning error (positioning accuracy) by a positioning device.

Means for Solving the Problems

[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 drivable body, a coupling part to which a work device can be connected to the body, a steering handle for steering the body by rotation, a positioning device provided on the body and detecting the body position based on signals from positioning satellites, an automatic steering mechanism capable of automatically steering the body based on the body position detected by the positioning device and a planned driving line, a correction switch for setting a correction amount, and a control device that controls the automatic steering mechanism to perform automatic steering based on the deviation between the body position detected by the positioning device and the planned driving line, which has been changed by the correction amount set by the correction switch, wherein the control device can change the correction amount of the operation unit of the correction switch.

[0008] The control device sets the correction amount based on the number of times the correction switch is operated, and the correction amount for the operation unit is the correction amount per operation of the correction switch.

[0009] The work vehicle is equipped with a display device that displays a screen for changing the correction amount of the operation unit, and the control device changes the correction amount corresponding to each operation of the correction switch based on the information displayed on the screen and input into a setting input unit that accepts input of the correction amount of the operation unit.

[0010] The control device sets the correction amount based on the amount of operation of the correction switch, and the correction amount for the operation unit is the correction amount per predetermined amount of operation of the correction switch.

[0011] The work vehicle is equipped with a display device that displays a screen for changing the correction amount of the operation unit, and the control device changes the correction amount per operation amount of the correction switch based on the information displayed on the screen and input into a setting input unit that accepts input of the correction amount of the operation unit.

[0012] The work vehicle is equipped with a display device that displays a first icon when the starting point of the reference line used to set the planned route is set, and displays a second icon when the ending point of the reference line is set.

[0013] The work vehicle is equipped with the work device connected to the coupling portion. [Effects of the Invention]

[0014] According to the present invention, even when steering or other operations are performed using the vehicle position detected by a positioning device, the influence of positioning errors by the positioning device can be reduced. [Brief explanation of the drawing]

[0015] [Figure 1] This is a diagram showing the configuration and control block diagram of the tractor. [Figure 2] This is an explanatory diagram illustrating automatic steering. [Figure 3A] This is an explanatory diagram illustrating the correction amount in a push switch. [Figure 3B] This is an explanatory diagram illustrating the correction amount in a slide switch. [Figure 4A] This diagram shows the first and second correction units in a push switch. [Figure 4B] This diagram shows the first and second correction units in a slide switch. [Figure 5A] This shows the state when the vehicle's calculated position shifts to the right while the vehicle is moving straight with automatic steering enabled. [Figure 5B] This shows the state when the vehicle's calculated position shifts to the left while the vehicle is moving straight with automatic steering enabled. [Figure 6] This is a view of the cover in front of the driver's seat, as seen from the driver's side. [Figure 7] This is an explanatory diagram illustrating automatic steering. [Figure 8A] This is a diagram showing an example of the M1 driver screen. [Figure 8B] This is a diagram showing the position deviation display unit. [Figure 9A]This is a diagram showing an example of displaying the positional deviation between the calculated vehicle body position W1 and the planned travel line L2 on the positional deviation display section. [Figure 9B] This is a diagram showing a state where the positional deviation between the corrected vehicle body position W3 and the planned travel line L2 is substantially zero on the positional deviation display section. [Figure 9C] This is a diagram showing a state where the positional deviation between the corrected vehicle body position W3 and the planned travel line L2 is large on the positional deviation display section. [Figure 10] This is an overall view of the tractor.

Embodiments for Carrying out the Invention

[0016] Hereinafter, embodiments of the present invention will be described based on the drawings.

[0017] FIG. 10 is a side view showing an embodiment of the work vehicle 1, and FIG. 10 is a plan view showing an embodiment of the work vehicle 1. In 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 or a transplanter, or a construction machine (construction vehicle) such as a loader working machine.

[0018] Hereinafter, the front side (in the direction of arrow A1 in FIG. 10) of the driver sitting in the driver's seat 10 of the tractor (work vehicle) 1 will be described as the front, the rear side (in the direction of arrow A2 in FIG. 10) as the rear, the left side (in the direction of arrow B1 in FIG. 10) as the left, and the right side (in the direction of arrow B2 in FIG. 10) as the right. Also, the horizontal direction (in the direction of arrow B3 in FIG. 10), which is the direction orthogonal to the front-rear direction of the work vehicle 1, will be described as the vehicle body width direction.

[0019] As shown in FIG. 10, 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 the tire type or the crawler type. Also, the rear wheels 7R may be of the tire type or the crawler type.

[0020] The prime mover 4 is a diesel engine, an electric motor, etc., and in this embodiment it is a diesel engine. The transmission 5 can switch the propulsion force of the running gear 7 by changing the gear, and can also switch the running gear 7 between forward and reverse. The vehicle body 3 is provided with a driver's seat 10.

[0021] Furthermore, a coupling section 8, consisting of a three-point linkage mechanism, is provided at the rear of the vehicle body 3. Working devices can be attached to and detached from the coupling section 8. By connecting the working devices to the coupling section 8, the vehicle body 3 can tow the working devices. The working devices include tilling devices for cultivating, fertilizer spreaders for spreading fertilizer, pesticide sprayers for spraying pesticides, harvesting devices for harvesting, mowing devices for cutting pasture grass, etc., spreading devices for spreading pasture grass, etc., hay collecting devices for collecting pasture grass, etc., and shaping devices for shaping pasture grass, etc.

[0022] As shown in Figure 1, the transmission 5 comprises a main shaft (drive shaft) 5a, a main transmission unit 5b, a sub-transmission unit 5c, a shuttle unit 5d, a PTO power transmission unit 5e, and a front transmission unit 5f. The drive shaft 5a is rotatably supported in the housing case (transmission case) of the transmission 5, and power from the crankshaft of the engine 4 is transmitted to the drive shaft 5a. The main transmission unit 5b has multiple gears and a shifter that changes the connection of these gears. The main transmission unit 5b changes the rotation input from the drive shaft 5a and outputs it (changes speed) by appropriately changing the connection (meshing) of the multiple gears with the shifter.

[0023] The sub-transmission unit 5c, like the main transmission unit 5b, has multiple gears and a shifter that changes the connections between these gears. The sub-transmission unit 5c changes the rotation input from the main transmission unit 5b and outputs it (changes the speed) by appropriately changing the connections (meshing) of the multiple gears with the shifter.

[0024] The shuttle unit 5d has a shuttle shaft 12 and a forward / reverse switching unit 13. Power output from the sub-transmission unit 5c is transmitted to the shuttle shaft 12 via gears or the like. The forward / reverse switching unit 13 is composed of, for example, a hydraulic clutch, and the rotation direction of the shuttle shaft 12, i.e., the forward and reverse movement of the tractor 1, is switched by engaging and disengaging the hydraulic clutch. The shuttle shaft 12 is connected to the rear wheel differential device 20R. The rear wheel differential device 20R rotatably supports the rear axle 21R to which the rear wheels 7R are attached.

[0025] The PTO power transmission unit 5e includes a PTO drive shaft 14 and a PTO clutch 15. The PTO drive shaft 14 is rotatably supported and capable of receiving power from the drive shaft 5a. The PTO drive shaft 14 is connected to the PTO shaft 16 via gears or the like. The PTO clutch 15 is, for example, a hydraulic clutch, and by engaging and disengaging the hydraulic clutch, it switches between a state in which power from the drive shaft 5a is transmitted to the PTO drive shaft 14 and a state in which power from the drive shaft 5a is not transmitted to the PTO drive shaft 14.

[0026] The front transmission unit 5f has a first clutch 17 and a second clutch 18. The first clutch 17 and the second clutch 18 are capable of receiving power from the drive shaft 5a, for example, power from the shuttle shaft 12 is transmitted via gears and a transmission shaft. Power from the first clutch 17 and the second clutch 18 can be transmitted to the front axle 21F via the front transmission shaft 22. Specifically, the front transmission shaft 22 is connected to the front differential device 20F, which rotatably supports the front axle 21F to which the front wheels 7F are attached.

[0027] The first clutch 17 and the second clutch 18 are composed of hydraulic clutches, etc. An oil passage is connected to the first clutch 17, and this oil passage is connected to a first operating valve 25 to which hydraulic fluid discharged from a hydraulic pump 33 is supplied. The first clutch 17 switches between an engaged state and an engaged state depending on the opening degree of the first operating valve 25. An oil passage is connected to the second clutch 18, and this oil passage is connected to a second operating valve 26. The second clutch 18 switches between an engaged state and an engaged 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 they switch between an engaged state and an engaged state by energizing or demagnetizing the solenoid of the solenoid valve.

[0028] When the first clutch 17 is disengaged and the second clutch 18 is engaged, power from the shuttle shaft 12 is transmitted to the front wheel 7F through the second clutch 18. This results in four-wheel drive (4WD) with the front wheel 7F and rear wheel 7R driven by power, and the rotational speeds of the front wheel 7F and rear wheel 7R are approximately the same (4WD constant speed state). On the other hand, when the first clutch 17 is engaged and the second clutch 18 is disengaged, it becomes four-wheel drive, and the rotational speed of the front wheel 7F is faster than the rotational speed of the rear wheel 7R (4WD increased speed state). Furthermore, when both the first clutch 17 and the second clutch 18 are engaged, power from the shuttle shaft 12 is not transmitted to the front wheel 7F, resulting in two-wheel drive (2WD) with the rear wheel 7R driven by power.

[0029] Tractor 1 is equipped with a positioning device 40. The positioning device 40 is a device that detects its own position (positioning information including latitude and longitude) using satellite positioning systems (positioning satellites) such as D-GPS, GPS, GLONASS, Beidou, Galileo, and Michibiki. That is, the positioning device 40 receives received signals (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 received signals. The positioning device 40 has a receiving device 41 and an inertial measurement unit (IMU) 42. The receiving device 41 has an antenna and the like and is a device that receives received signals transmitted from the positioning satellite, and is mounted on the vehicle body 3 separately from the inertial measurement unit 42. In this embodiment, the receiving device 41 is mounted on a locating device provided on the vehicle body 3. Note that the mounting location of the receiving device 41 is not limited to this embodiment.

[0030] The inertial measuring device 42 includes an acceleration sensor for detecting acceleration, a gyro sensor for detecting angular velocity, and the like. It is installed below the vehicle body 3, for example, the driver's seat 10, and the inertial measuring device 42 can detect the roll angle, pitch angle, yaw angle, etc., of the vehicle body 3.

[0031] As shown in Figure 1, the tractor 1 is equipped with a steering device 11. The steering device 11 is capable of manual steering, in which the vehicle body 3 is steered by the driver, and automatic steering, in which the vehicle body 3 is steered automatically without driver intervention.

[0032] The steering system 11 includes a steering handle (steering wheel) 30 and a steering shaft (rotating axis) 31 that rotatably supports the steering handle 30. The steering system 11 also includes an auxiliary mechanism (power steering device) 32. The auxiliary mechanism 32 assists the rotation of the steering shaft 31 (steering handle 30) by hydraulics or the like. The auxiliary mechanism 32 includes a hydraulic pump 33, a control valve 34 to which hydraulic fluid discharged from the hydraulic pump 33 is supplied, and a steering cylinder 35 operated by the control valve 34. The control valve 34 is a three-position switching valve that can be switched by the movement of a spool, for example, 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 wheel 7F.

[0033] Therefore, when the driver grips the steering wheel 30 and operates it in one direction or the other, the switching position and opening degree of the control valve 34 are switched in accordance with the direction of rotation of the steering wheel 30, and the steering cylinder 35 extends or retracts to the left or right in accordance with the switching position and opening degree of the control valve 34, thereby changing the steering direction of the front wheels 7F. In other words, the vehicle body 3 can change its direction of travel to the left or right by manually steering the steering wheel 30.

[0034] Next, I will explain automatic steering.

[0035] As shown in Figure 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 that is parallel to the driving reference line L1. In automatic steering, the tractor 1 (vehicle body 3) is automatically steered in the direction of travel so that the vehicle position measured by the positioning device 40 matches the planned driving line L2.

[0036] Specifically, before automatic steering is performed, the tractor 1 (vehicle body 3) is moved to a predetermined position in the field (S1), and when the driver operates the steering switch 52 provided on the tractor 1 at the predetermined position (S2), the vehicle position measured by the positioning device 40 is set to the starting point P10 of the driving reference line L1 (S3). Then, when the tractor 1 (vehicle body 3) is moved from the starting point P10 of the driving reference line L1 (S4), and when the driver operates the steering switch 52 at the predetermined position (S5), the vehicle position measured by the positioning device 40 is set to the ending point P11 of the driving reference line L1 (S6). Therefore, the straight line connecting the starting point P10 and the ending point P11 is set as the driving reference line L1.

[0037] After setting the reference driving line L1 (after S6), for example, if the tractor 1 (vehicle body 3) is moved to a location different from where the reference driving line L1 was set (S7), and the driver operates the steering switch 52 (S8), a planned driving line L2, which is a straight line parallel to the reference driving line L1, is set (S9). After setting the planned driving line L2, automatic steering is started, and the direction of travel of the tractor 1 (vehicle body 3) is changed to follow the planned driving line L2. For example, if the current vehicle position is to the left of the planned driving line L2, the front wheels 7F are steered to the right, and if the current vehicle position is to the right of the planned driving line L2, the front wheels 7F are steered to the left. During automatic steering, the driving speed (vehicle speed) of the tractor 1 (vehicle body 3) can be changed by the driver manually changing the amount of operation of the accelerator member (accelerator pedal, accelerator lever) provided on the tractor 1, or by changing the gear of the transmission 5.

[0038] Furthermore, after automatic steering has started, the driver can terminate automatic steering by operating the steering selector switch 52 at any point. In other words, the endpoint of the planned driving line L2 can be set by terminating automatic steering by operating the steering selector switch 52. This means that the length from the start to the end of the planned driving line L2 can be set to be longer or shorter than the driving reference line L1. In other words, the planned driving line L2 is not associated with the length of the driving reference line L1, and the vehicle can be driven while automatically steering for a longer distance than the length of the driving reference line L1 by following the planned driving line L2.

[0039] As shown in Figure 1, the steering system 11 has an automatic steering mechanism 37. The automatic steering mechanism 37 is a mechanism that performs automatic steering of the vehicle body 3, and automatically steers the vehicle body 3 based on the position of the vehicle body 3 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 axis of the steering motor 38 and rotating together with the rotation axis. When the rotation axis of the steering motor 38 rotates, the steering shaft 31 automatically rotates (moves) via the gear mechanism 39, and the steering direction of the front wheels 7F can be changed so that the vehicle body position matches the planned driving line L2.

[0040] As shown in Figure 1, the tractor 1 is equipped with a display device 45. The display device 45 is a device capable of displaying various information about the tractor 1, and is capable of displaying at least the driving information of the tractor 1. The display device 45 is located in front of the driver's seat 10.

[0041] As shown in Figure 1, the tractor 1 is equipped with a setting switch 51. The setting switch 51 is a switch that switches to a setting mode in which at least the settings before the start of automatic steering are made. The setting mode is a mode in which various settings related to automatic steering are made before the start of automatic steering, for example, a mode in which the start and end points of the driving reference line L1 are set.

[0042] The setting switch 51 can be switched ON or OFF. When ON, it outputs a signal indicating that the setting mode is active, and when OFF, it outputs a signal indicating that the setting mode is inactive. Additionally, when the setting switch 51 is ON, it outputs a signal to the display device 45 indicating that the setting mode is active, and when OFF, it outputs a signal to the display device 45 indicating that the setting mode is inactive.

[0043] Tractor 1 is equipped with a steering selector switch 52. The steering selector switch 52 is a switch that switches the start or end of automatic steering. Specifically, the steering selector switch 52 can be switched up, down, forward, and backward from the neutral position. When the setting mode is active and the switch is set downward from the neutral position, it outputs the start of automatic steering. When the setting mode is active and the switch is set upward from the neutral position, it outputs the end of automatic steering. Furthermore, when the steering selector switch 52 is set backward from the neutral position and the setting mode is active, it outputs that the current vehicle position is set to the starting point P10 of the driving reference line L1. When the steering selector switch 52 is set forward from the neutral position and the setting mode is active, it outputs that the current vehicle position is set to the end point P11 of the driving reference line L1.

[0044] Tractor 1 is equipped with a correction switch 53. The correction switch 53 is a switch that corrects the vehicle position (latitude, longitude) measured by the positioning device 40. In other words, the correction switch 53 is a switch that corrects the vehicle position (referred to as the calculated vehicle position) calculated using satellite signals (position of the positioning satellite, transmission time, correction information, etc.) and measurement information (acceleration, angular velocity) measured by the inertial measuring device 42.

[0045] The compensation switch 53 consists of either a push switch that can be pressed or a slide switch that can be slid. The following describes the cases where the compensation switch 53 is a push switch and a slide switch, respectively.

[0046] If the correction switch 53 is a push switch, the correction amount is set based on the number of times the push switch is operated. The correction amount is determined by correction amount = number of operations × correction amount per operation (correction amount per unit). For example, as shown in Figure 3A, the correction amount increases by several centimeters or 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, and the first control device 60A sets (calculates) the correction amount based on the number of operations. The first control device 60A can change a predetermined operation of the push switch, i.e., the correction amount per operation. When a predetermined operation is performed on the display device 45, the first control device 60A displays a setting screen on the display device 45 for setting the correction amount. The setting screen displays a setting input section for inputting the correction amount per operation of the push switch (correction amount per unit). The correction amount per unit in the setting input section can be input by operating the display device 45. The correction amount per unit input to the setting input section of the display device 45 can be stored in the first control device 60A. In other words, by inputting a correction amount per unit into the setting input section, for example, the correction amount per unit shown in Figure 3A can be changed from 2 cm to 4 cm.

[0047] Furthermore, if the correction switch 53 is a slide switch, the correction amount is set based on the amount of operation (displacement) of the slide switch. For example, the correction amount is determined by the correction amount = displacement from a predetermined position. For example, as shown in Figure 3B, the correction amount increases by several centimeters or tens of centimeters for every 5 mm increase in the displacement of the slide switch. The amount of operation (displacement) of the slide switch is input to the first control device 60A, and the first control device 60A sets (calculates) the correction amount based on the displacement. Note that even if the correction switch 53 is a slide switch, the correction amount can be changed in the same way as with a push switch.

[0048] When a predetermined operation is performed on the display device 45, the first control device 60A displays a setting screen on the display device 45 for setting the correction amount. The setting screen displays a setting input section for inputting a predetermined operation of the slide switch, that is, a correction amount (correction amount per unit) for the displacement of the slide switch. The correction amount per unit in the setting input section can be input by operating the display device 45, and the input correction amount per unit can be stored in the first control device 60A. In other words, by inputting a correction amount per unit in the setting input section, for example, as shown in Figure 3B, the correction amount (correction amount per unit) for every 5 mm increase in displacement can be changed from 2 cm to 4 cm. Note that the method of increasing the correction amount and the rate of increase are not limited to the values ​​described above.

[0049] As shown in Figures 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 the part that commands the correction of 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 the part that commands the correction of the vehicle body position corresponding to the other side in the width direction of the vehicle body 3, i.e., the right side.

[0050] As shown in Figure 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 automatically return to their original position each time an operation is performed. The switches constituting the first correction unit 53A and the switches constituting the second correction unit 53B are integrated. However, the switches constituting the first correction unit 53A and the switches constituting the second correction unit 53B may be spaced apart from each other. As shown in Figure 3A, each time the first correction unit 53A is pressed, the correction amount corresponding to the left side of the vehicle body 3 (left correction amount) increases. Also, each time the second correction unit 53B is pressed, the correction amount corresponding to the right side of the vehicle body 3 (right correction amount) increases.

[0051] As shown in Figure 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 elongated hole. When the correction switch 53 is a slide switch, the first correction unit 53A and the second correction unit 53B are spaced apart from each other in the width direction. As shown in Figure 3B, when the knob 55 is gradually displaced to the left from a predetermined reference position, the left correction amount increases according to the amount of displacement. Also, when the knob 55 is gradually displaced to the right from a predetermined reference position, the right correction amount increases according to the amount of displacement. In addition, as shown in Figure 4B, when it is a slide switch, the first correction unit 53A and the second correction unit 53B may be formed as an integrated unit, the reference position of the knob 55 may be set to the center, the left correction amount may be set when it is moved to the left from the reference position, and the right correction amount may be set when the knob 55 is moved to the right from the intermediate position.

[0052] Next, we will explain the relationship between the correction amount (left correction amount, right correction amount) by the correction switch 53, the planned travel line L2, and the behavior (travel trajectory) of the tractor 1 (vehicle body 3).

[0053] Figure 5A shows the state when the calculated vehicle position W1 shifts to the right while the vehicle is moving straight during automatic steering. As shown in Figure 5A, when automatic steering is started, if the actual position of the tractor 1 (vehicle body 3) (actual position W2) and the calculated vehicle position W1 coincide, and the actual position W2 coincides with the planned driving line L2, the tractor 1 will drive along the planned driving line L2. That is, in section P1 where there is no error in the positioning of the positioning device 40 and the vehicle position detected by the positioning device 40 (calculated vehicle position W1) is the same as the actual position W2, the tractor 1 will drive along the planned driving line L2. Note that if there is no error in the positioning of the positioning device 40 and no correction is performed, the calculated vehicle position W1 and the corrected vehicle position (corrected vehicle position) W3 corrected by the correction amount are the same value. The corrected vehicle position W3 is given by Corrected Vehicle Position W3 = Calculated Vehicle Position W1 - Correction Amount.

[0054] Here, near position P20, even though the actual position W2 is not deviated from the planned driving line L2, various factors cause an error in the positioning device 40's positioning, and the vehicle position W1 detected by the positioning device 40 is deviated to the right of the planned driving line L2 (actual position W2). If the deviation amount W4 is maintained, the tractor 1 will determine that there is a deviation between the calculated vehicle position W1 and the planned driving line L2, and will steer the tractor 1 to the left to eliminate the deviation amount W4 between the calculated vehicle position W1 and the planned driving line L2. As a result, the actual position W2 of the tractor 1 will shift to the planned driving line L2 due to the left steering. Subsequently, suppose the driver notices that the tractor 1 is deviating from the planned driving line L2, and at position P21, steers the second correction unit 53B to increase the right correction amount from zero. A rightward correction amount is applied to the calculated vehicle body position W1, and the corrected vehicle body position (corrected vehicle body position) W3 can be made approximately the same as the actual position W2. In other words, by setting the rightward 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 amount of deviation W4 that occurred near position P20. Furthermore, as shown in position P21 in Figure 5A, if the actual position W2 of the tractor 1 is to the left of the planned travel line L2 after the vehicle body position correction, 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.

[0055] Figure 5B shows the state when the calculated vehicle position W1 shifts to the left while the vehicle is moving straight during automatic steering. As shown in Figure 5B, when automatic steering is started, if the actual position W2 and the calculated vehicle position W1 coincide, and the actual position W2 coincides with the planned travel line L2, then, similar to Figure 5A, the tractor 1 will travel along the planned travel line L2. That is, similar to Figure 5A, in the section P2 where there is no error in the positioning of the positioning device 40, the tractor 1 will travel along the planned travel line L2. Also, similar to Figure 5A, the calculated vehicle position W1 and the corrected vehicle position W3 are the same value.

[0056] Here, at position P22, due to various influences, an error occurs in the positioning of the positioning device 40, causing the vehicle position W1 detected by the positioning device 40 to shift to the left relative to the actual position W2, and assuming that the shift amount W5 is maintained, the tractor 1 will steer to the right to eliminate the shift amount W5 between the calculated vehicle position W1 and the planned driving line L2. Subsequently, suppose the driver notices that the tractor 1 is deviating from the planned driving line L2, and the driver steers the first correction unit 53A at position P23 to increase the left correction amount from zero. In this case, the left correction amount is added to the calculated vehicle position W1, and the corrected vehicle position (corrected vehicle position) W3 can be made approximately the same as the actual position W2. In other words, by setting the left correction amount with the first correction unit 53A, the vehicle position of the positioning device 40 can be corrected in a direction that eliminates the shift amount W5 that occurred near position P22. Furthermore, as shown at position P23 in Figure 5B, if, after correcting the vehicle position, the actual position W2 of tractor 1 is to the right of the planned travel line L2, tractor 1 will be steered to the left, bringing its actual position W2 into alignment with the planned travel line L2.

[0057] Next, we will explain the setting switch 51, the calibration switch 53, and the screen switching switch 54.

[0058] As shown in Figure 6, the outer circumference of the steering shaft 31 is covered by the steering post 180. The outer circumference of the steering post 180 is covered by a cover 177. The cover 177 is located in front of the driver's seat 10. The cover 177 includes a panel cover 178 and a column cover 179.

[0059] 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 wheel 30. The upper plate portion 178a also has a mounting surface 178f to which a setting switch 51, a correction switch 53, and a screen switching switch 54 are attached. The mounting surface 178f is located behind the support portion 178e and below the steering wheel 30. The support portion 178e and the mounting surface 178f are continuous, with the support portion 178e located at the front of the upper plate portion 178a and the mounting surface 178f located at the rear of the upper plate portion 178a. The setting switch 51, correction switch 53, and screen switching switch 54 are mounted on the mounting surface 178f. As a result, the setting switch 51, the calibration switch 53, and the screen switching switch 54 are arranged around the steering shaft 31.

[0060] A shuttle lever 181 protrudes from the left plate portion 178b of the panel cover 178. The shuttle lever 181 is a component used to switch the direction of travel of the vehicle body 3. More specifically, by operating (swinging) the shuttle lever 181 forward, the forward / reverse switching unit 13 outputs forward power to the running gear 7, and the direction of travel of the vehicle body 3 is switched to the forward direction. Conversely, by operating (swinging) the shuttle lever 181 backward, the forward / reverse switching unit 13 outputs reverse power to the running gear 7, and the direction of travel 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 running gear 7.

[0061] The column cover 179 is located below the steering wheel 30 and covers the upper part of the steering shaft 31. The column cover 179 is formed in a roughly 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, the calibration switch 53, and the screen switching switch 54, which are mounted on the mounting surface 178f, are located around the column cover 179.

[0062] Next, the placement of the setting switch 51, steering selector switch 52, correction switch 53, and screen selector switch 54 will be described in detail. As shown in Figure 6, the setting switch 51, steering selector switch 52, correction switch 53, and screen selector switch 54 are arranged around the steering shaft 31.

[0063] The setting switch 51 is located on one side (left) of the steering shaft 31. The steering selector switch 52 is located on one side (left) of the steering shaft 31. In this embodiment, the steering selector switch 52 consists of a pivotable lever. The steering selector switch 52 is pivotable with a base end provided on the steering shaft 31 side as the pivot point. The base end of the steering selector switch 52 is located inside the column cover 179. The steering selector switch 52 protrudes from one side (left) of the column cover 179.

[0064] The correction switch 53 is located on the other side (right side) of the steering shaft 31. More specifically, the correction switch 53 is located to the right and rear (diagonally to the right rear) of the steering shaft 31. In relation to the column cover 179, the correction switch 53 is located to the right and rear (diagonally to the right rear) of the column cover 179. In relation to the mounting surface 178f of the panel cover 178, the correction switch 53 is located at the right rear of the mounting surface 178f. By positioning the correction switch 53 at the rear of the inclined mounting surface 178f, a longer distance can be secured between the correction switch 53 and the steering wheel 30. This makes it possible to more reliably prevent unintended operation of the correction switch 53 or steering of the steering wheel 30.

[0065] The screen switching switch 54 is located on the other side (right side) of the steering shaft 31. More specifically, the screen switching switch 54 is located to the right and in front (diagonally to the front right) of the steering shaft 31. In relation to the column cover 179, the screen switching switch 54 is located to the right and in front (diagonally to the front right) of the column cover 179. In relation to the mounting surface 178f of the panel cover 178, the screen switching switch 54 is located on the front right side of the mounting surface 178f. Furthermore, the screen switching switch 54 is located in front of the correction switch 53.

[0066] As described above, the setting switch 51, steering selector switch 52, correction switch 53, and screen selector switch 54 are arranged around the steering shaft 31. In other words, the setting switch 51, steering selector switch 52, correction switch 53, and screen selector switch 54 are concentrated around the steering shaft 31. Therefore, the driver can easily see the location of each switch. In addition, the driver can operate each switch without changing their posture while seated in the driver's seat 10. This improves operability and prevents accidental operation. Furthermore, the harnesses (wiring) routed from each switch can be shortened.

[0067] Furthermore, the arrangement of the switches described above may be reversed, with the left and right sides swapped. In other words, one side may be on the left and the other on the right, or one side may be on the right and the other on the left. Specifically, for example, the setting switch 51 and the steering selector switch 52 may be placed on the right side of the steering shaft 31, and the correction switch 53 may be placed on the left side of the steering shaft 31.

[0068] As shown in Figure 1, the tractor 1 is equipped with multiple control devices 60. These multiple control devices 60 are devices that control the travel system, the work system, calculate the vehicle position, etc. of the tractor 1. The multiple control devices 60 are the first control device 60A, the second control device 60B, and the third control device 60C.

[0069] The first control device 60A receives the received signal (received information) received by the receiving device 41 and the measured information (acceleration, angular velocity, etc.) measured by the inertial measuring device 42, and determines the vehicle position based on the received information and the measured information. For example, if the correction amount by the correction switch 53 is zero, that is, if no correction of the vehicle position by the correction switch 53 is commanded, the first control device 60A does not perform any correction on the calculated vehicle position W1 calculated from the received information and the measured information, and determines the calculated vehicle position W1 to be the vehicle position used during automatic steering. On the other hand, if a correction of the vehicle position by the correction switch 53 is commanded, the first control device 60A sets the correction amount for the vehicle position based on either the number of times the correction switch 53 is operated or the amount of operation (displacement) of the correction switch 53, and determines the corrected vehicle position W3, obtained by correcting the calculated vehicle position W1 with the correction amount, to be the vehicle position used during automatic steering.

[0070] The first control device 60A sets a control signal based on the vehicle position (calculated vehicle position W1, corrected vehicle position W3) and the planned travel line L2, and outputs the control signal to the second control device 60B. Based on the control signal output from the first control device 60A, the second control device 60B controls the steering motor 38 of the automatic steering mechanism 37 so that the vehicle 3 travels along the planned travel line L2.

[0071] As shown in Figure 7, if the deviation between the vehicle position and the planned travel line L2 is less than a threshold, the second control device 60B maintains the rotation angle of the steering motor 38's rotation axis. If the deviation between the vehicle position and the planned travel line L2 is greater than or equal to the threshold, and the tractor 1 is positioned to the left of the planned travel line L2, the second control device 60B rotates the rotation axis of the steering motor 38 so that the steering direction of the tractor 1 is to the right. If the deviation between the vehicle position and the planned travel line L2 is greater than or equal to the threshold, and the tractor 1 is positioned to the right of the planned travel line L2, the second control device 60B rotates the rotation axis of the steering motor 38 so that the steering direction of the tractor 1 is to the left. In the above-described embodiment, the steering angle of the steering device 11 was changed based on the deviation between the vehicle body position and the planned travel line L2. However, if the direction of the planned travel line L2 and the direction of travel (vehicle body direction) F1 of the tractor 1 (vehicle body 3) are different, that is, if the angle θ of the vehicle body direction F1 with respect to the planned travel line L2 is greater than or equal to a threshold, the second control device 60B may set the steering angle so that the angle θ is zero (vehicle body direction F1 coincides with the direction of the planned travel line L2). Furthermore, the second control device 60B may set the final steering angle in automatic steering based on the steering angle obtained based on the deviation (position deviation) and the steering angle obtained based on the direction (direction deviation θ). The setting of the steering angle in automatic steering in the above-described embodiment is just an example and is not limited to this.

[0072] The third control device 60C raises and lowers the coupling section 8 in response to the operation of an operating member provided around the driver's seat 10. The first control device 60A, the second control device 60B, and the third control device 60C may be integrated. Furthermore, the control of the driving system, the control of the work system, and the calculation of the vehicle body position described above are not limited.

[0073] Settings related to the operation of the vehicle body 3 can be made using the display device 45.

[0074] The details of the display device 45 will be described below.

[0075] As shown in Figure 1, the display device 45 can acquire various information detected by the detection device 47 via an in-vehicle network or the like. The detection device 47 includes an accelerator pedal sensor, a shift lever detection sensor, a crank position sensor, a fuel sensor, a water temperature sensor, a prime mover speed sensor, a steering angle sensor, an oil temperature sensor, an axle rotation sensor, etc. For example, the display device 45 can display driving information such as the remaining fuel amount detected by the fuel sensor, the water temperature value detected by the water temperature sensor, and the prime mover speed detected by the prime mover speed sensor.

[0076] Furthermore, the display device 45 can acquire information from various switches, such as the setting switch 51, the steering selector switch 52, and the correction switch 53. The display device 45 can acquire information on whether the setting switch 51 is ON or OFF, information on the start and end of automatic steering from the steering selector switch 52, and information on the commands for the starting point P10 and ending point P11 of the driving reference line L1 from the steering selector switch 52.

[0077] As shown in Figure 6, the display device 45 includes a display unit 46 that displays various information. The display unit 46 includes a fixed display unit 46A that displays warnings, etc., and a variable display unit 46B that can change the information displayed. The fixed display unit 46A has a panel on which warnings, etc., are displayed, and an illumination unit such as an LED that illuminates the symbols on the panel with a light source. The variable display unit 46B is composed of a panel such as an organic EL or liquid crystal and displays various information related to the operation (driving) of the tractor 1.

[0078] The display device 45 can display the amount of deviation between the vehicle body 3 and the planned route L2. Specifically, the display device 45 displays the positional deviation (amount of deviation) between the vehicle body position (calculated vehicle body position) W1 detected by the positioning device 40 and the planned route L2. When a predetermined operation is performed on the display device 45, the display device 45 displays the driving screen M1.

[0079] The operating screen M1 has an operating display unit 61 that shows operating information. The operating display unit 61 includes a rotation display unit 62 that displays the rotation speed of the prime mover 4 (prime mover rotation speed) as operating information. The rotation display unit 62 includes a level display unit 63. The level display unit 63 is a part that displays the prime mover rotation speed in steps. For example, the level display unit 63 includes a scale unit 65 and an indicator unit 80. The scale unit 65 has, for example, a first line 65A and a plurality of second lines 65B that are assigned at predetermined intervals along the first line 65A. The scale unit 65 also has a third line 65C that is spaced at a predetermined interval from the first line 65A. The first line 65A and the third line 65C are formed in a semicircular shape, for example, with one end (for example, the left side) being the minimum value and the other end (for example, the right side) being the maximum value.

[0080] The indicator section 80 is a bar whose length changes according to the magnitude of the engine speed. For example, the indicator section 80 is located between the first line 65A and the third line 65C. When the engine speed is at its minimum value of zero, it is located on one end (left side) of the first line 65A and the third line 65C and is the shortest in length. When the engine speed is at its maximum value, it extends from one end (left side) of the first line 65A and the third line 65C to the other end (right side) of the first line 65A and the third line 65C and is the longest in length. The rotation display section 62 includes a numerical display section 64. The numerical display section 64 displays the engine speed in numbers. For example, the rotation display section 62 is located inside the semicircle of the first line 65A and the third line 65C.

[0081] Therefore, according to the operation display unit 61, the prime mover speed, such as engine speed, can be displayed in stages by the level display unit 63 and also displayed numerically by the speed display unit 62.

[0082] The driving screen M1 has an icon display section 67 that displays multiple icon sections 66. The icon display section 67 is the part that displays various information using the icon sections 66. Specifically, it displays settings related to driving, such as automatic steering, for example, the setting status set in setting mode, using the icon sections 66. The icon display section 67 is located in a different position from the driving display section 61, for example, it is located at the top of the driving screen M1.

[0083] The multiple icon sections 66 are the first icon section 66A, the second icon section 66B, the third icon section 66C, the fourth icon section 66D, the fifth icon section 66E, the sixth icon section 66F, and the seventh icon section 66G. Note that the operation screen M1 does not need to have all of the multiple icon sections 66 (66A, 66B, 66C, 66D, 66E, 66F, 66G), and is not limited to the embodiments described above.

[0084] The first icon section 66A is displayed when a warning occurs. The second icon section 66B is displayed when the starting point P10 of the driving reference line L1 is set. The third icon section 66C is displayed when the ending point P11 of the driving reference line L1 is set.

[0085] The fourth icon section 66D is displayed when automatic steering is permitted. For example, the fourth icon section 66D is displayed when the setting mode is active, the setting of the driving reference line L1 is complete, and the heading determination unit 207 of the second control device 60B has permitted automatic steering. By looking at the fourth icon section 66D, the operator can understand that automatic steering is permitted. The operator can then start automatic steering by operating the steering switch 52.

[0086] The fifth icon section 66E is displayed when the coupling section 8 is in the raised or lowered position. The sixth icon section 66F is displayed when the 4WD speed is increased. The seventh icon section 66G changes color, etc., according to the reception sensitivity of the receiving signal of the receiving device 41.

[0087] As shown in Figures 8A and 8B, the driving screen M1 has a position deviation display unit 68. The position deviation display unit 68 is a part that displays the position deviation (amount of deviation) between the calculated vehicle position W1 and the planned driving line L2 in steps. The position deviation display unit 68 includes a scale unit 68a and an indicator unit 68b. The scale unit 68a includes an origin 68a1 and a data line 68a2 that extends horizontally from the origin 68a1 across the driving screen M1. The origin 68a1 indicates the point where the position deviation is zero and is located in the longitudinal center of the data line 68a2. The data line 68a2 is a part that indicates the magnitude of the position deviation, and the opposite side from the origin 68a1 is set to the maximum value. In data line 68a2, the area to the left (one side) of the origin 68a1 represents the position deviation when the vehicle body 3 is displaced to the left (one side) from the planned travel line L2, and the area to the right (the other side) of the origin 68a1 represents the position deviation when the vehicle body 3 is displaced to the right (the other side) from the planned travel line L2. In addition, data line 68a2 shows auxiliary scales divided into multiple stages, and the magnitude of the position deviation can be grasped by the indicator unit 68b pointing to the auxiliary scales.

[0088] The indicator section 68b indicates the magnitude of the current position deviation and moves along the data line 68a2. When the position deviation is zero, the indicator section 68b is located in the longitudinal center of the data line 68a2 and coincides with the origin 68a1. When the vehicle body 3 is displaced to the left (one side) from the planned travel line L2 and the position deviation is at its maximum value, the indicator section 68b is located at the left end of the data line 68a2. When the vehicle body 3 is displaced to the right (the other side) from the planned travel line L2 and the position deviation is at its maximum value, the indicator section 68b is located at the right end of the data line 68a2. For example, when the position deviation is 1 cm, the indicator section 68b moves one division of the data line 68a2 to the left or right from the origin 68a1. When the position deviation is 5 cm, the indicator section 68b moves five divisions of the data line 68a2 to the left or right from the origin 68a1. Note that the positional deviation values ​​are examples only and are not limited to specific cases.

[0089] In this way, the position deviation display unit 68 displays the result detected by the positioning device 40, that is, the position deviation (amount of deviation) between the calculated vehicle body position W1 and the planned travel line L2, making it easy to understand the timing of correction by the correction switch 53 and whether or not correction is being made. For example, during automatic steering, if a position deviation is displayed on the position deviation display unit 68 even though the actual position W2 of the tractor 1 (vehicle body 3) and the planned travel line L2 are the same, the driver (operator) can determine that the position deviation displayed on the position deviation display unit 68 is due to a positioning error of the positioning device 40. If the position deviation is increasing due to a positioning error of the positioning device 40, as described above, the movement of the tractor 1 (vehicle body 3) due to the positioning error of the positioning device 40 can be suppressed by operating the correction switch 53 to add a correction amount to the calculated vehicle body position W1.

[0090] In the embodiment described above, the position deviation display unit 68 displayed the position deviation between the calculated vehicle body position W1 and the planned travel line L2. However, at least after operating the correction switch 53, the position deviation between the corrected vehicle body position W3, which is the corrected position deviation corrected by the correction switch 53, and the planned travel line L2 may be displayed. For the convenience of the following explanation, the position deviation between the calculated vehicle body position W1 and the planned travel line L2 will be referred to as the "first position deviation W10," and the position deviation between the corrected vehicle body position W3 and the planned travel line L2 will be referred to as the "second position deviation W11."

[0091] Specifically, as shown in Figure 9A, after the start of automatic steering, if the correction switch 53 is not operated, the position deviation display unit 68 displays the first position deviation W10 (S51). Furthermore, after the start of automatic steering, if the correction switch 53 is operated (either the first correction unit 53A or the second correction unit 53B is operated), as shown in Figures 9B and 9C, the position deviation display unit 68 switches the display from the first position deviation W10 to the second position deviation W11 (S52). For example, after the correction switch 53 is operated, the indicator unit 68b points to the value of the second position deviation W11 on the scale unit 68a.

[0092] Figure 9A shows a state where, despite the actual position W2 of the tractor 1 (vehicle body 3) and the planned travel line L2 being the same, a first position deviation W10 is displayed on the left side of the position deviation display unit 68 due to a positioning error in the positioning device 40. Figure 9B shows a state where, similar to Figure 9A, a first position deviation W10 occurs due to a positioning error in the positioning device 40, but a second position deviation W11 is displayed on the position deviation display unit 68 after operating the first correction unit 53A. As shown in Figure 9B, if the second position deviation W11 displayed on the position deviation display unit 68 is approximately zero, it can be determined that the first correction unit 53A has performed an appropriate correction. On the other hand, if the second position deviation W11 displayed on the position deviation display unit 68 after operating the first correction unit 53A is not zero and is relatively large, it can be determined that the amount of correction by operating the first correction unit 53A is small. In other words, if the second position deviation W11 displayed on the position deviation display unit 68 is large after operating the first correction unit 53A of the correction switch 53, the driver will know that it is necessary to operate the first correction unit 53A to further increase the correction amount. In this case, the driver operates the first correction unit 53A until the second position deviation W11 becomes zero, as shown in Figure 9B. By displaying the second position deviation W11 on the position deviation display unit 68 in this way, it is possible to determine whether the correction amount obtained by operating the correction switch 53 is appropriate or not.

[0093] Furthermore, after operating the first correction unit 53A of the correction switch 53, if the second position deviation W11 displayed on the position deviation display unit 68 becomes zero as shown in Figure 9B, and then increases after a certain period of time as shown in Figure 9C, it can be determined that the positioning error of the positioning device 40 has been eliminated. In this case, the driver can stabilize the behavior of the tractor 1 (vehicle body 3) by performing an operation to set the correction amount by the correction switch 53 to zero.

[0094] The work vehicle 1 comprises a drivable vehicle body 3, a steering handle 30 for steering the vehicle body 3 by rotation, a positioning device 40 provided on the vehicle body 3 and detecting the vehicle body position based on signals from positioning satellites, a correction switch 53 for commanding correction of the vehicle body position detected by the positioning device 40, an automatic steering mechanism 37 capable of automatically steering the vehicle body 3 based on the vehicle body position detected by the positioning device 40 and the planned driving line L2, and a display device 45 capable of displaying the positional deviation between the vehicle body position detected by the positioning device 40 and the planned driving line L2. According to this, when the vehicle body position can be corrected by the correction switch 53, the display device 45 can display the positional deviation between the vehicle body position (calculated vehicle body position) detected by the positioning device 40 and the planned driving line L2. Therefore, in a situation where the tractor 1 (vehicle body 3) and the planned travel line L2 actually coincide, if the positional deviation between the calculated vehicle body position and the planned travel line L2 is displayed on the display device 45, the driver (operator) can understand that the positional deviation is caused by a positioning error by the positioning device 40. In other words, by looking at the positional deviation displayed on the display device 45, the driver can understand the effect of the positioning error (positioning accuracy) by the positioning device 40, and if there is a positioning error, the driver can correct the calculated vehicle body position used for automatic steering using the correction switch 53.

[0095] The display device 45 displays the positional deviation between the corrected vehicle position, which is the vehicle position corrected by the correction switch 53, and the planned travel line L2. This allows the driver to understand the positional deviation of the planned travel line L2 relative to the corrected vehicle position after operating the correction switch 53.

[0096] The correction switch 53 includes a first correction unit 53A that commands correction of the vehicle body position on one side in the width direction of the vehicle body 3, and a second correction unit 53B that commands correction of the vehicle body position on the other side in the width direction of the vehicle body. This makes it possible to easily correct the vehicle body position on one side or the vehicle body position on the other side of the vehicle body 3.

[0097] The work vehicle 1 is equipped with a control device 60 to which a correction switch 53 is connected and which controls the automatic steering mechanism 37. The control device 60 sets the amount of correction for the vehicle body position based on the number of times the correction switch 53 is operated. Thus, the amount of correction can be set (changed) by the number of times the correction switch 53 is operated.

[0098] The control device 60 changes the amount of correction corresponding to each operation of the correction switch 53. This allows the amount of correction for each operation of the correction switch 53 to be changed, so that the automatic steering of the vehicle body 3 can be changed according to various situations. For example, by making the amount of correction for each operation of the correction switch 53 smaller, fine adjustments can be made to the automatic steering, and by making the amount of correction for each operation of the correction switch 53 larger, rough adjustments can be made to the automatic steering.

[0099] The control device 60 changes the amount of correction per unit of operation of the correction switch 53. This allows the correction amount when the correction switch 53 is operated by a predetermined amount to be changed, so that the automatic steering of the vehicle body 3 can be changed according to various situations by operating the correction switch 53. For example, by making the correction amount when the correction switch 53 is operated by a predetermined amount smaller, fine adjustments can be made to the automatic steering, and by making the correction amount when the correction switch 53 is operated by a predetermined amount larger, rough adjustments can be made to the automatic steering.

[0100] The embodiments disclosed herein should be considered in all respects to be illustrative and not restrictive. The scope of the present invention is indicated by the claims rather than by the foregoing description, and all modifications within the meaning and scope equivalent to the claims are intended to be included.

[0101] In the embodiment described above, the display device 45 displayed the position deviation, but it may also display the azimuth deviation between the direction of the planned travel line L2 and the direction of travel (vehicle orientation) F1 of the tractor 1 (vehicle body 3). When displaying the azimuth deviation in the display device 45, the position deviation described above can be replaced with the azimuth deviation. [Explanation of symbols]

[0102] 1. Work vehicles 3. Vehicle Body 30 Steering Wheel 37 Automatic steering mechanism 40 Positioning device 45 Display device 53. Correction switch 53A First Correction Unit 53B 2nd correction section 60 Control device L2 Scheduled Driving Line

Claims

1. A vehicle that can be driven, A connecting part to which a work device can be connected to the vehicle body, A steering wheel that steers the vehicle body by rotational operation, A positioning device provided on the vehicle body and which detects the vehicle body position based on signals from positioning satellites, An automatic steering mechanism capable of automatically steering the vehicle based on the vehicle position detected by the positioning device and the planned driving line, A correction switch for setting the correction amount, A control device that controls the automatic steering mechanism to perform automatic steering based on the deviation between the vehicle position detected by the positioning device and the planned driving line, which has been modified by the correction amount set by the correction switch, Equipped with, The control device is a work vehicle capable of changing the correction amount of the operation unit of the correction switch.

2. The control device sets the correction amount based on the number of times the correction switch is operated. The work vehicle according to claim 1, wherein the correction amount for the operation unit is the correction amount per operation of the correction switch.

3. The system includes a display device that shows a screen for changing the correction amount of the aforementioned operation unit, The control device changes the correction amount corresponding to one operation of the correction switch based on information input to a setting input unit which is displayed on the screen and accepts input of the correction amount for the operation unit, according to claim 2.

4. The control device sets the correction amount based on the amount of operation of the correction switch. The work vehicle according to claim 1, wherein the correction amount of the operation unit is the correction amount per predetermined operation amount of the correction switch.

5. The system includes a display device that shows a screen for changing the correction amount of the aforementioned operation unit, The control device changes the amount of correction per operation of the correction switch based on information input to a setting input unit which is displayed on the screen and accepts input of the correction amount of the operation unit, according to claim 4.

6. A work vehicle according to any one of claims 1 to 5, comprising a display device that displays a first icon when the starting point of the reference line used for setting the planned route is set, and displays a second icon when the ending point of the reference line is set.

7. A work vehicle according to any one of claims 1 to 6, comprising the work device connected to the connecting portion.

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