JP7059122B2 - Work vehicle - Google Patents

Description

The present invention relates to, for example, a work vehicle.

Conventionally, Patent Document 1 is known as an agricultural work machine. The agricultural work machine of Patent Document 1 is a traveling machine capable of switching between manual traveling by manual steering and automatic traveling by automatic steering along a set traveling line set parallel to a reference traveling line, and manual traveling and automatic traveling. It is equipped with a changeover switch that can be switched between running and running. Further, the agricultural work machine sets the start point of the reference travel line after pressing the right instruction button while traveling along the ridge, and sets the end point of the reference travel line by pressing the left instruction button while traveling. That is, the reference traveling line is set before the automatic steering.

Japanese Unexamined Patent Publication No. 2017-12803

In the agricultural work machine of Patent Document 1, automatic running can be easily performed by switching from manual running to automatic running with a changeover switch. In automatic driving, in order to control the agricultural work machine so that the agricultural work machine travels along the reference traveling line, it is desired that the agricultural work machine goes straight immediately before the start of automatic driving. If the automatic running is started when the farming machine is not in a straight running state, the behavior of the farming machine during the initial running may not be stable.

Therefore, in view of the above problems, it is an object of the present invention to provide a work vehicle capable of stably traveling when switching from manual steering to automatic steering.

The technical means of the present invention for solving this technical problem is characterized by the following points.
The work vehicle travels by either a steering device having a steering handle, manual steering by the steering handle, or automatic steering of the steering handle that steers along a planned travel line set based on a travel reference line. Based on a possible vehicle body , a steering angle detection device provided on the vehicle body that detects the steering angle of the steering device, and a plurality of steering angles of the steering device when the vehicle body travels a predetermined distance in the manual steering. The control device for permitting the automatic steering and a steering changeover switch for switching between the start and the end of the automatic steering on the scheduled travel line, which is not associated with the length of the travel reference line, are provided. The control device has the steering in the turning section where the steering angle detected by the steering angle detecting device exceeds the turning determination steering angle after the position where the steering changeover switch is operated and the automatic steering is completed. The steering angle detected by the angle detection device is not acquired as the plurality of steering angles, and the steering angle detected by the steering angle detection device is determined in advance from the position where the steering angle is equal to or less than the turning determination steering angle. The steering angle acquisition unit that acquires the steering angle detected by the steering angle detection device at predetermined time intervals within the distance or a predetermined determination time as the plurality of steering angles, and the steering angle acquisition unit acquire the steering angle . A steering determination unit that determines whether or not to permit the start of the automatic steering based on a plurality of steering angles, and a steering changeover switch that determines whether or not to permit the start of the automatic steering is started by the steering determination unit. It has an automatic steering control unit that controls the steering device to perform automatic steering when switching is performed .

The steering determination unit obtains the standard deviations and average values of the plurality of steering angles, and if all the steering angles are within a predetermined value determined based on the standard deviations, permits the start of automatic steering, and one. Automatic when the steering angle of the unit exceeds the predetermined value determined based on the standard deviation.
Do not allow the start of steering.

The work vehicle is provided with a display device that indicates that the start of the automatic steering is permitted by the steering determination unit.
The steering determination unit permits the start of the automatic steering when the variation of the plurality of steering angles is within a predetermined range.
The work vehicle includes a positioning device capable of detecting the position of the vehicle body, and a reference line setting switch for setting the position of the vehicle body detected by the positioning device at the start position and the end position of the travel reference line. ..
When the variation of the plurality of steering angles is within a predetermined range, the steering determination unit performs the first permission to permit automatic steering related to steering, and the orientation of the vehicle body detected by the positioning device and the traveling reference line. When the orientation is within a predetermined range, the second permission for permitting automatic steering regarding the orientation is given, and the automatic steering control unit receives the first permission and the second permission in the steering determination unit. When the start switching of the automatic steering is performed by the steering changeover switch in the determined state, the automatic steering is started.

According to the present invention, stable running can be achieved when switching from manual steering to automatic steering.

It is a figure which shows the structure of a tractor and a control block diagram. It is explanatory drawing explaining the automatic steering. It is explanatory drawing explaining the correction amount in a push switch. It is explanatory drawing explaining the correction amount in a slide switch. It is a figure which shows the 1st correction part and the 2nd correction part in a push switch. It is a figure which shows the 1st correction part and the 2nd correction part in a slide switch. It shows the state when the calculated vehicle body position shifts to the right while going straight during automatic steering. It shows the state when the calculated vehicle body position shifts to the left while going straight during automatic steering. It is the figure which looked at the cover in front of the driver's seat from the driver's seat side. It is explanatory drawing explaining the control in automatic steering. It is explanatory drawing of the condition of automatic steering. It is a figure which shows the state of acquiring a plurality of steering angles θn. This is an example of a distribution map when there is little variation in a plurality of steering angles θn. This is an example of a distribution map when there are many variations in a plurality of steering angles θn. It is a figure which shows an example of the operation screen. It is explanatory drawing explaining the traveling of a tractor on a slope. It is an overall view of a tractor.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
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 the tractor, and may be an agricultural machine (agricultural vehicle) such as a combine or a transplant machine, or a construction machine (construction vehicle) such as a loader work machine.

Hereinafter, the front side of the driver (in the direction of arrow A1 in FIG. 13) seated in the driver's seat 10 of the tractor (working vehicle) 1 is in the front, the rear side of the driver (in the direction of arrow A2 in FIG. 13) is in the rear, and the left side of the driver. Will be described as the left side, and the driver's right side as the right side. Further, the horizontal direction, which is a direction orthogonal to the front-rear direction of the work vehicle 1, will be described as the vehicle body width direction.
As shown in FIG. 13, the tractor 1 includes a vehicle body 3, a motor 4, and a transmission 5. The vehicle body 3 has a traveling device 7 and can travel. The traveling device 7 is a device having a front wheel 7F and a rear wheel 7R. The front wheel 7F may be a tire type or a crawler type. Further, the rear wheel 7R may also be a tire type or a crawler type.

The prime mover 4 is a diesel engine, an electric motor, or the like, and is composed of a diesel engine in this embodiment. The speed change device 5 can switch the propulsive force of the traveling device 7 by shifting, and can also switch between forward and reverse movement of the traveling device 7. The vehicle body 3 is provided with a driver's seat 10.
Further, a connecting portion 8 composed of a three-point link mechanism or the like is provided at the rear portion of the vehicle body 3. A working device can be attached to and detached from the connecting portion 8. By connecting the working device to the connecting portion 8, the working device can be towed by the vehicle body 3. The working equipment is a tilling device for cultivating, a fertilizer spraying device for spraying fertilizer, a pesticide spraying device for spraying pesticides, a harvesting device for harvesting, a cutting device for cutting grass, a spreading device for spreading grass, and grass. It is a grass collecting device that collects grass, a molding device that molds grass, and the like.

As shown in FIG. 1, the transmission 5 includes a main shaft (propulsion shaft) 5a, a main transmission 5b, an auxiliary transmission 5c, a shuttle 5d, a PTO power transmission unit 5e, a front transmission 5f, and the like. It is equipped with. The propulsion shaft 5a is rotatably supported by a housing case (mission case) of the transmission 5, and power from the crank shaft of the engine 4 is transmitted to the propulsion shaft 5a. The main transmission 5b has a plurality of gears and a shifter for changing the connection of the gears. The main speed change unit 5b changes the rotation input from the propulsion shaft 5a and outputs (shifts) by appropriately changing the connection (meshing) of a plurality of gears with a shifter.

Like the main transmission unit 5b, the auxiliary transmission unit 5c has a plurality of gears and a shifter for changing the connection of the gears. The auxiliary transmission 5c changes the rotation input from the main transmission 5b and outputs (shifts) by appropriately changing the connection (meshing) of a plurality of gears with a shifter.
The shuttle section 5d has a shuttle shaft 12 and a forward / backward switching section 13. The power output from the auxiliary transmission unit 5c is transmitted to the shuttle shaft 12 via gears and the like. The forward / backward switching unit 13 is composed of, for example, a hydraulic clutch or the like, and switches the rotation direction of the shuttle shaft 12, that is, the forward movement and the reverse movement of the tractor 1 by turning on / off 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 wheel 7R is attached.

The PTO power transmission unit 5e has a PTO propulsion shaft 14 and a PTO clutch 15. The PTO propulsion shaft 14 is rotatably supported and can transmit power from the propulsion shaft 5a. The PTO propulsion shaft 14 is connected to the PTO shaft 16 via a gear or the like. The PTO clutch 15 is composed of, for example, a hydraulic clutch or the like, and is in a state where the power of the propulsion shaft 5a is transmitted to the PTO propulsion shaft 14 and the power of the propulsion shaft 5a is not transmitted to the PTO propulsion shaft 14 by turning the hydraulic clutch on and off. Switch to the state.

The front speed change unit 5f has a first clutch 17 and a second clutch 18. The first clutch 17 and the second clutch can transmit the power from the propulsion shaft 5a, for example, the power of the shuttle shaft 12 is transmitted via the gear and the transmission shaft. The 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 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.

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 switches between a connected state and a disconnected 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 switches between a connected state and a disconnected state depending on the opening degree of the second operating valve 26. The first actuated valve 25 and the second actuated valve 26 are, for example, a two-position switching valve with a solenoid valve, and are switched to a connected state or a disconnected state by exciting or degaussing the solenoid of the solenoid valve.

When the first clutch 17 is in the disengaged state and the second clutch 18 is in the connected 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 wheels and the rear wheels are driven by power in four-wheel drive (4WD), and the rotation speeds of the front wheels and the rear wheels are substantially the same (4WD constant velocity state). On the other hand, when the first clutch 17 is in the connected state and the second clutch 18 is in the disengaged state, the four-wheel drive is performed and the rotation speed of the front wheels is faster than the rotation speed of the rear wheels (4WD speed increase state). Further, when the first clutch 17 and the second clutch 18 are in the disengaged state, the power of the shuttle shaft 12 is not transmitted to the front wheels 7F, so that the rear wheels are driven by power (2WD).

The tractor 1 includes a positioning device 40. The positioning device 40 can detect its own position (positioning information including latitude and longitude) by a satellite positioning system (positioning satellite) such as D-GPS, GPS, GLONASS, Hokuto, Galileo, and Michibiki. That is, the positioning device 40 receives the satellite signal (position of the positioning satellite, transmission time, correction information, etc.) transmitted from the positioning satellite, and detects the position (for example, latitude, 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 having an antenna or the like and receiving a satellite signal transmitted from a 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 lops provided on the vehicle body 3. The mounting location of the receiving device 41 is not limited to the embodiment.

The inertial measurement unit 42 includes an acceleration sensor that detects acceleration, a gyro sensor that detects angular velocity, and the like. The vehicle body 3, for example, provided below the driver's seat 10, can detect the roll angle, pitch angle, yaw angle, etc. of the vehicle body 3 by the inertial measurement unit 42.
As shown in FIG. 1, the tractor 1 includes 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 automatically steered without the driver's operation.

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. Further, the steering device 11 has an auxiliary mechanism (power steering device) 32. The auxiliary mechanism 32 assists the rotation of the steering shaft 31 (steering handle 30) by hydraulic pressure or the like. The auxiliary 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 moving the spool or the like, and switches according to the steering direction (rotational 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.

Therefore, if the driver grips the steering handle 30 and operates it in one direction or the other direction, the switching position and opening degree of the control valve 34 are switched according to the rotation direction of the steering handle 30, and the control valve 34 is switched. The steering direction of the front wheel 7F can be changed by expanding and contracting the steering cylinder 35 to the left or right according to the switching position and opening degree of. That is, the vehicle body 3 can change the traveling direction to the left or right by manually steering the steering handle 30.

Next, automatic steering will be described.
As shown in FIG. 2, when performing automatic steering, first, the traveling reference line L1 is set before performing automatic steering. After setting the travel reference line L1, automatic steering can be performed by setting the travel schedule line L2 parallel to the travel reference line L1. In the 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 and the planned travel line coincide with L2.

Specifically, the tractor 1 (vehicle body 3) is moved to a predetermined position in the field (S1) before the automatic steering is performed, and the driver operates the steering changeover switch 52 provided on the tractor 1 at the predetermined position. When this is done (S2), the vehicle body position measured by the positioning device 40 is set at the start point P10 of the travel reference line L1 (S3). Further, when the tractor 1 (vehicle body 3) is moved from the starting point P10 of the traveling reference line L1 (S4) and the driver operates the steering changeover switch 52 at a predetermined position (S5), the measurement is performed by the positioning device 40. The vehicle body position is set at the end point P11 of the travel reference line L1 (S6). Therefore, the straight line connecting the start point P10 and the end point P11 is set as the travel reference line L1.

After setting the travel reference line L1 (after S6), for example, the tractor 1 (vehicle body 3) is moved to a location different from the location where the travel reference line L1 is set (S7), and the driver operates the steering changeover switch 52. (S8), the planned travel line L2, which is a straight line parallel to the travel reference line L1, is set (S9). After setting the scheduled travel line L2, automatic steering is started, and the traveling direction of the tractor 1 (vehicle body 3) is changed so as to be along the scheduled travel line L2. For example, if the current vehicle body position is on the left side of the scheduled travel line L2, the front wheels 7F are steered to the right, and if the current vehicle body position is on the right side of the scheduled travel line L2, the front wheels 7F are steered to the right. Is steered to the left. During automatic steering, the traveling speed (vehicle speed) of the tractor 1 (vehicle body 3) may be manually changed by the driver by changing the operation amount of the accelerator member (accelerator pedal, accelerator lever) provided on the tractor 1. It can be changed by changing the shift stage of the transmission.

Further, after the start of automatic steering, if the driver operates the steering changeover switch 52 at an arbitrary position, the automatic steering can be ended. That is, the end point of the scheduled travel line L2 can be set by the end of 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 scheduled travel line L2 can automatically steer a distance longer than the length of the travel reference line L1 while traveling.

As shown in FIG. 1, the steering device 11 has an automatic steering mechanism 37. Automatic steering mechanism 3
Reference numeral 7 is a mechanism for automatically steering the vehicle body 3, and automatically steers the vehicle body 3 based on the position (vehicle body 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 that can control the rotation direction, rotation speed, rotation angle, and the like based on the vehicle body position. The gear mechanism 39 includes a gear provided on the steering shaft 31 and rotating around the steering shaft 31, and a gear provided on the rotating shaft of the steering motor 38 and rotating around the rotating shaft. When the rotation shaft of the steering motor 38 rotates, the steering shaft 31 automatically rotates (rotates) via the gear mechanism 39, and the steering direction of the front wheels 7F is set so that the vehicle body position coincides with the planned traveling line L2. Can be changed.

As shown in FIG. 1, the tractor 1 includes a display device 45. The display device 45 is a device capable of displaying various information about the tractor 1, and can display at least the operation information of the tractor 1. The display device 45 is provided in front of the driver's seat 10.
As shown in FIG. 1, the tractor 1 includes a setting switch 51. The setting switch 51 is a switch for switching to a setting mode for setting at least before the start of automatic steering. The setting mode is a mode in which various settings related to the automatic steering are performed before the automatic steering is started, and for example, a mode in which the start point and the end point of the traveling reference line L1 are set.

The setting switch 51 can be switched to ON or OFF, and outputs a signal in which the setting mode is valid when it is ON, and outputs a signal in which the setting mode is invalid when it is OFF. Further, the setting switch 51 outputs a signal for which the setting mode is valid to the display device 45 when it is ON, and outputs a signal for which the setting mode is invalid to the display device 45 when it is OFF.

The tractor 1 includes 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 selector switch 52 can be switched from the neutral position to the top, bottom, front, and rear, and when the setting mode is enabled and the steering switch 52 is switched from the neutral position to the bottom, automatic steering is started. It outputs, and when the setting mode is enabled and the position is switched upward from the neutral position, the end of automatic steering is output. Further, the steering changeover switch 52 outputs that the current vehicle body position is set at the start point P10 of the traveling reference line L1 when the setting mode is enabled and the setting mode is later switched from the neutral position, and the steering changeover switch 52 is used. 52 outputs that when the setting mode is enabled and the neutral position is switched forward, the current vehicle body position is set at the end point P11 of the travel reference line L1. That is, the steering changeover switch 52 also serves as a reference line setting switch for setting the start position (start point P10) and end position (end point P11) of the travel reference line L1. The steering changeover switch 52 may be configured separately from the steering changeover switch 52 for switching the start or end of automatic steering and the reference line setting switch.

The tractor 1 includes a correction switch 53. The correction switch 53 is a switch that corrects the vehicle body position (latitude, longitude) measured by the positioning device 40. That is, the correction switch 53 is a vehicle body position (referred to as an calculated vehicle body position) calculated by a satellite signal (position of a positioning satellite, transmission time, correction information, etc.) and measurement information (acceleration, angular velocity) measured by the inertial measurement unit 42. ) Is a switch to correct.

The correction switch 53 is composed of a push switch that can be pressed or a slide switch that can be slid. Hereinafter, a case where the correction switch 53 is a push switch and a slide switch will be described.
When the correction switch 53 is a push switch, the correction amount is set based on the number of operations of the push switch. The correction amount is determined by the correction amount = the number of operations × the amount of correction per number of operations. For example, as shown in FIG. 3A, the correction amount increases by several centimeters or several tens of centimeters each time the push switch is operated. The number of operations of the push switch 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.

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 = the amount of displacement from a predetermined position. For example, as shown in FIG. 3B, every time the displacement amount of the slide switch increases by 5 mm, the correction amount increases by several centimeters or several tens of centimeters. The operation amount (displacement amount) 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 amount. The method of increasing the correction amount and the rate of increase described above are not limited to the above-mentioned numerical values.

Specifically, as shown in FIGS. 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 portion that commands correction of the vehicle body position corresponding to one side in the width direction of the vehicle body 3, that is, the left side. The second correction unit 53B is a portion that commands correction of the vehicle body position corresponding to the other side in the width direction of the vehicle body 3, that is, the right side.

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 automatically return each time an operation is performed. 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, each 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. Further, each 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.

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 portion 55 that moves to the left or right along the longitudinal direction of the elongated hole. There is. When the correction switch 53 is a slide switch, the first correction unit 53A and the second correction unit 53B are arranged apart from each other in the width direction. As shown in FIG. 3B, when the knob 55 is gradually displaced to the left from a predetermined reference position, the left correction amount increases according to the displacement amount. Further, when the knob portion 55 is gradually displaced to the right from a predetermined reference position, the right correction amount increases according to the displacement amount. As shown in FIG. 4B, in the case of a slide switch, the first correction unit 53A and the second correction unit 53B are integrally formed, the reference position of the knob portion 55 is set in the center portion, and the reference position is reached. The left correction amount may be set when the knob 55 is moved to the left side, and the right correction amount may be set when the knob 55 is moved from the intermediate position to the right side.

Next, the relationship between the correction amount (left correction amount, right correction amount) by the correction switch 53, the scheduled travel line L2, and the behavior (travel locus) of the tractor 1 (vehicle body 3) will be described.
FIG. 5A shows a state in which the calculated vehicle body position W1 is displaced to the right during automatic steering and going straight. As shown in FIG. 5A, in the state where the automatic steering is started, the actual position (actual position W2) of the tractor 1 (vehicle body 3) and the calculated vehicle body position W1 match, and the actual position W2 and the planned travel line If it matches L2, the tractor 1 travels along the scheduled travel line L2. That is, in the section P1 in which 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 scheduled travel line L2. .. If there is no error in the positioning of the positioning device 40 and no correction is performed, the calculated vehicle body position W1 and the corrected vehicle body position (corrected vehicle body position) W3 corrected by the correction amount are the same values. The corrected vehicle body position W3 is the corrected vehicle body position W3 = calculated vehicle body position W1-correction amount.

Here, in the vicinity of the position P20, although the actual position W2 does not deviate from the scheduled travel line L2, an error occurs in the positioning of the positioning device 40 due to various influences, and the positioning device 40 detects it. Assuming that the vehicle body position W1 is displaced to the right with respect to the planned traveling line L2 (actual position W2) and the deviation amount W4 is maintained, the tractor 1 is displaced between the calculated vehicle body position W1 and the planned traveling line L2. It is determined that the tractor 1 has occurred, and the tractor 1 is steered to the left so as to eliminate the deviation amount W4 between the calculated vehicle body position W1 and the scheduled travel line L2. Then, the actual position W2 of the tractor 1 is shifted to the scheduled traveling line L2 by steering to the left. After that, it is assumed that the driver notices that the tractor 1 is deviated from the scheduled travel line L2 and steers the second correction unit 53B at the position P21 to increase the right correction amount from zero. The 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 substantially the same as the actual position W2. That is, 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 the direction of eliminating the deviation amount W4 generated in the vicinity of the position P20. As shown in the position P21 of FIG. 5A, when the actual position W2 of the tractor 1 is separated from the scheduled traveling line L2 to the left after the correction of the vehicle body position, the tractor 1 is steered to the right and the tractor 1 is steered to the right. The actual position W2 can be matched with the scheduled travel line L2.

FIG. 5B shows a state in which the calculated vehicle body position W1 is displaced to the left during automatic steering and going straight. As shown in FIG. 5B, when the actual position W2 and the calculated vehicle body position W1 match, and the actual position W2 and the planned traveling line L2 match in the state where the automatic steering is started, the actual position W2 and the planned traveling line L2 match. Similarly, the tractor 1 travels along the scheduled travel line L2. That is, as in FIG. 5A, the tractor 1 travels along the scheduled travel line L2 in the section P2 where there is no error in the positioning of the positioning device 40. Further, similarly to FIG. 5A, the calculated vehicle body position W1 and the corrected vehicle body position W3 have the same values.

Here, at the position P22, an error occurs in the positioning of the positioning device 40 due to various influences, the vehicle body position W1 detected by the positioning device 40 shifts to the left side with respect to the actual position W2, and the shift amount W5 is maintained. If so, the tractor 1 steers the tractor 1 to the right so as to eliminate the deviation amount W5 between the calculated vehicle body position W1 and the scheduled travel line L2. After that, it is assumed that the driver notices that the tractor 1 is deviated from the scheduled travel line L2, and the driver 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 substantially the same as the actual position W2. That is, 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 the direction of eliminating the deviation amount W5 generated in the vicinity of the position P22. As shown in the position P23 in FIG. 5B, when the actual position W2 of the tractor 1 is separated from the scheduled traveling line L2 to the right after the correction of the vehicle body position, the tractor 1 is steered to the left and the tractor 1 is steered to the left. The actual position W2 can be matched with the scheduled travel line L2.

Next, the setting switch 51 and the correction switch 53 will be described.
As shown in FIG. 6, the outer periphery of the steering shaft 31 is covered with the steering post 180. The outer circumference of the steering post 180 is covered with 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.

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. Further, the upper plate portion 178a has a mounting surface 178f to which the setting switch 51 and the correction switch 53 are mounted. The mounting surface 178f is provided behind the support portion 178e and below the steering handle 30. The support portion 178e and the mounting surface 178f are continuous, the support portion 178e is located at the front portion of the upper plate portion 178a, and the mounting surface 178f is located at the rear portion of the upper plate portion 178a. The setting switch 51 and the correction switch 53 are mounted on the mounting surface 178f. As a result, the setting switch 51 and the correction switch 53 are arranged around the steering shaft 31.

The shuttle lever 181 projects from the left plate portion 178b of the panel cover 178. The shuttle lever 181 is a member that performs an operation of switching the traveling direction of the vehicle body 3. More specifically, by operating (swinging) the shuttle lever 181 forward, the forward / backward switching unit 13 is in a state of outputting forward power to the traveling device 7, and the traveling direction of the vehicle body 3 is switched to the forward direction. Further, by operating (swinging) the shuttle lever 181 backward, the forward / backward switching unit 13 is in a state of outputting the 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.

The column cover 179 is arranged below the steering handle 30 and covers the periphery of the upper part of the steering shaft 31. The column cover 179 is formed in a substantially square cylinder shape, and projects upward from the mounting surface 178f of the panel cover 178. That is, the mounting surface 178f is provided around the column cover 179. Therefore, the setting switch 51 and the correction switch 53 mounted on the mounting surface 178f are arranged around the column cover 179.

Next, the arrangement of each of the setting switch 51, the steering changeover switch 52, and the correction switch 53 will be described in detail. As shown in FIG. 6, the setting switch 51, the steering changeover switch 52, and the correction switch 53 are arranged around the steering shaft 31.
The setting switch 51 is arranged on one side (left side) of the steering shaft 31. The steering changeover switch 52 is arranged on one side (left side) of the steering shaft 31. In the case of the present embodiment, the steering changeover switch 52 is composed of a swingable lever. The steering changeover switch 52 can swing with the base end portion provided on the steering shaft 31 side as a fulcrum. The base end portion of the steering changeover switch 52 is provided inside the column cover 179. The steering selector switch 52 projects to one side (left side) of the column cover 179.

The correction switch 53 is arranged on the other side (right side) of the steering shaft 31. More specifically, the correction switch 53 is arranged to the right and rearward (obliquely right rearward) of the steering shaft 31. The correction switch 53 is arranged on the right side and rearward (diagonally right rearward) of the column cover 179 in the positional relationship with the column cover 179. The correction switch 53 is arranged at the right rear portion of the mounting surface 178f in the positional relationship with the mounting surface 178f of the panel cover 178. By arranging the correction switch 53 at the rear portion of the inclined mounting surface 178f, it is possible to secure a long distance between the correction switch 53 and the steering handle 30. As a result, unintended operation of the correction switch 53 and steering of the steering handle 30 can be prevented more reliably.

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 collectively present around the steering shaft 31. Therefore, the driver can grasp the position of each switch at a glance. In addition, the driver can operate each switch while sitting in the driver's seat 10 without changing his / her posture. Therefore, the operability is improved and erroneous operation can be prevented. In addition, the harness (wiring) arranged from each switch can be shortened.

Regarding the arrangement of the switches described above, the left and right may be exchanged and arranged. That is, one side may be on the left and the other side may be on the right, or one side may be on the right and the other side may be on 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.

As shown in FIG. 1, the tractor 1 includes a plurality of control devices 60. The plurality of control devices 60 are devices that control the traveling system in the tractor 1, control the working system, calculate the vehicle body position, and the like. The plurality of control devices 60 are a first control device 60A, a second control device 60B, and a third control device 60C.
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 unit 42, and the vehicle body position is based on the received information and the measurement information. Ask for. For example, in the first control device 60A, 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 calculated vehicle body calculated by the received information and the measurement information. The calculated vehicle body position W1 is determined to be the vehicle body position used during automatic steering without correcting the position W1. On the other hand, when the correction of the vehicle body position by the correction switch 53 is commanded, the first control device 60A determines the vehicle body position based on either the number of operations of the correction switch 53 or the operation amount (displacement amount) of the correction switch 53. The correction amount is set, and the corrected vehicle body position W3 obtained by correcting the calculated vehicle body position W1 with the correction amount is determined as the vehicle body position to be used during automatic steering.

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 scheduled 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 an electric / electronic circuit provided in the second control device 60B, a program stored in a CPU, and the like. The automatic steering control unit 200 controls the steering motor 38 of the automatic steering mechanism 37 so that the vehicle body 3 travels along the scheduled travel line L2 based on the control signal output from the first control device 60A.

As shown in FIG. 7, when the deviation between the vehicle body position and the planned travel line L2 is less than the threshold value, 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 scheduled travel line L2 is equal to or greater than the threshold value and the tractor 1 is located on the left side with respect to the scheduled travel line L2, the automatic steering control unit 200 has the steering direction of the tractor 1 on the right. The rotation axis of the steering motor 38 is rotated so as to be in the direction. When the deviation between the vehicle body position and the scheduled travel line L2 is equal to or greater than the threshold value and the tractor 1 is located on the right side of the scheduled travel line L2, the automatic steering control unit 200 has the steering direction of the tractor 1 on the left. The rotation axis of the steering motor 38 is rotated so as to be in the 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, but the direction of the planned travel line L2 and the traveling direction of the tractor 1 (vehicle body 3). When the direction (vehicle body direction) F1 of the (traveling direction) is different, that is, when the angle θg of the vehicle body orientation F1 with respect to the planned traveling line L2 is equal to or greater than the threshold value, the automatic steering control unit 200 has zero angle θg (vehicle body direction). The steering angle may be set so that F1 coincides with the direction of the planned traveling line L2). Further, the automatic steering control unit 200 sets the final steering angle in automatic steering based on the steering angle obtained based on the deviation (positional deviation) and the steering angle obtained based on the azimuth (direction deviation). You may. The setting of the steering angle in the automatic steering in the above-described embodiment is an example and is not limited.

The third control device 60C raises and lowers the connecting portion 8 in response to the operation of the 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. Further, the above-mentioned control of the traveling system, control of the working system, and calculation of the vehicle body position are not limited.
As described above, the control device 60 can automatically steer the tractor 1 (vehicle body 3).

By the way, in order to perform automatic steering after setting the traveling reference line L1, it is necessary to prepare the conditions for automatic steering. For example, as shown in FIG. 8, when the tractor 1 is after turning and before the automatic steering, the tractor 1 is meandering more than a predetermined value (when the vehicle body orientation of the tractor 1 and the traveling reference line L1 are significantly different). For example, it is difficult to steer the tractor 1 along the planned travel line L2 parallel to the travel reference line L1 even if the automatic steering is started. In such a case, the second control device 60B is a condition for automatic steering. Judges that it is not in place.

The second control device 60B has a plurality of steering angles θn (n = 1, 2, 3 ...) Of the steering device 11 when the tractor 1 (vehicle body 3) travels a predetermined distance at least before automatic steering, that is, in manual steering. Permission for automatic steering is granted based on n).
As shown in FIG. 1, the second control device 60B includes a steering angle acquisition unit 201 and a steering determination unit 202 in addition to the automatic steering control unit 200. The steering angle acquisition unit 201 and the steering determination unit 202 are composed of an electric / electronic circuit provided in the second control device 60B, a program stored in a CPU, and the like.

The steering angle acquisition unit 201 acquires at least a plurality of steering angles θn of the steering device 11 during manual steering. The steering angle acquisition unit 201 acquires the steering angle θn detected by the steering angle detection device 205 provided on the vehicle body 3 at predetermined time intervals. As shown in FIG. 9, for example, it is assumed that the steering changeover switch 52 is operated at the position P12 and the automatic steering is completed. After the position P12, the steering angle θ is a large value in the turning section T1, and the steering angle acquisition unit 201 can determine that the tractor 1 is in a turning state. Therefore, the steering angle θ in the turning section T1 is acquired. do not. The steering angle acquisition unit 201 continuously acquires a plurality of steering angles θn after the position P13 at which the current steering angle θM1 is equal to or less than the turning steering angle (turning determination steering angle θM2). For example, the steering angle acquisition unit 201 acquires a plurality of steering angles θn from the position P13 within a predetermined determination distance J1 or the tractor 1 from the position P13 within a predetermined determination time.

The steering determination unit 202 determines whether or not to allow the start of automatic steering based on the plurality of steering angles θn acquired by the steering angle acquisition unit 201. The steering determination unit 202 permits the start of automatic steering when the variation of the plurality of steering angles θn acquired by the steering angle acquisition unit 201 is within a predetermined range, and the variation of the plurality of steering angles θn is out of the predetermined range. Do not allow automatic steering in some cases.
As shown in FIG. 10A, the steering determination unit 202 obtains, for example, the standard deviation and the average value of a plurality of steering angles θn, and permits the start of automatic steering when all the steering angles θn are within 3σ. On the other hand, as shown in FIG. 10B, the steering determination unit 202 does not allow the start of automatic steering when a part of the steering angle θn is in a region exceeding 3σ. That is, when the steering of the steering handle 30 is stable and the vehicle body 3 is considered to be traveling straight, the steering determination unit 202 permits automatic steering, the steering of the steering handle 30 is not stable, and the vehicle body is not stable. If it is not considered that 3 is traveling in a straight direction, automatic steering is not permitted. In the above-described embodiment, the steering angle acquisition unit 201 does not acquire a plurality of steering angles θn during turning, but instead, the steering angle acquisition unit 201 acquires a plurality of steering angles θn during turning. Then, the steering determination unit 202 excludes the steering angle θn during turning from the plurality of steering angles θn acquired by the steering angle acquisition unit 201, and then uses the excluded steering angle θn to determine automatic steering. You may go.

When the steering changeover switch 52 switches the start of automatic steering in a state where the steering determination unit 202 determines that the permission is granted, the automatic steering control unit 200 controls the steering device 11 as described above. , Performs automatic steering.
The display device 45 can display that the start of automatic steering is determined to be permitted by the steering determination unit 202. As shown in FIG. 11, when a predetermined operation is performed on the display device 45, the display device 45 displays the operation screen M1.

The operation screen M1 has an operation display unit 61 showing operation information. The operation display unit 61 includes a rotation display unit 62 that displays the rotation speed (motor rotation speed) of the prime mover 4 as operation information. The rotation display unit 62 includes a level display unit 63. The level display unit 63 is a part that displays the motor rotation speed step by step. For example, the level display unit 63 includes a scale unit 65 and an index unit 80. The scale portion 65 has, for example, a first line 65A and a plurality of second lines 65B assigned at predetermined intervals along the first line 65A. Further, the scale portion 65 has a first line 65A and a third line 65C separated by a predetermined interval. The first line 65A and the third line 65C are formed in a semicircular shape, for example, with one end side (for example, the left side) having the minimum value and the other end side (for example, the right side) having the maximum value. ..

The index unit 80 is a bar whose length changes according to the magnitude of the motor rotation speed. The index unit 80 is located, for example, between the first line 65A and the third line 65C, and when the value of the prime mover rotation speed is the minimum value of zero, the index unit 80 is located on the first line 65A and the third line 65C. When the length is the shortest on one end side (left side) and the value of the prime mover rotation speed is the maximum value, the first line 65A and the first line 65A from one end side (left side) of the first line 65A and the third line 65C. It extends to the other end side (right side) of the third line 65C and has the longest length. The rotation display unit 62 includes a number display unit 64. The numerical display unit 64 displays the motor rotation speed numerically. For example, the rotation display unit 62 is arranged inside the semicircle of the first line 65A and the third line 65C.

Therefore, according to the operation display unit 61, the prime mover rotation speed such as the engine rotation speed can be displayed stepwise by the level display unit 63 and can be displayed numerically by the rotation display unit 62.
The operation screen M1 has an icon display unit 67 that displays a plurality of icon units 66. The icon display unit 67 is a portion where various information is indicated by the icon unit 66. That is, the icon unit 66 displays the setting related to running such as automatic steering, for example, the setting state set in the setting mode. The icon display unit 67 is located at a position different from that of the operation display unit 61, and is arranged, for example, at the upper part of the operation screen M1.

The plurality of icon units 66 are a first icon unit 66A, a second icon unit 66B, a third icon unit 66C, a fourth icon unit 66D, a fifth icon unit 66E, a sixth icon unit 66F, and a seventh icon unit 66G. .. The operation screen M1 does not have to have all of the plurality of icon portions 66 (66A, 66B, 66C, 66D, 66E, 66F, 66G), and is not limited to the above-described embodiment.

The first icon unit 66A is displayed when a warning occurs. The second icon portion 66B is displayed when the start point P10 of the travel reference line L1 is set. The third icon portion 66C is displayed when the end point P11 of the travel reference line L1 is set.
The fourth icon unit 66D is displayed when automatic steering is permitted. For example, the fourth icon unit 66D is displayed when the setting mode is valid and the setting of the travel reference line L1 is completed, and the steering determination unit 202 of the second control device 60B permits automatic steering. By looking at the fourth icon unit 66D, the operator can grasp that the automatic steering is permitted. Then, the operator can start the automatic steering by operating the steering changeover switch 52.

The fifth icon portion 66E is displayed when the connecting portion 8 is in the ascending / descending state. The sixth icon unit 66F is displayed when the speed is increased by 4WD. The color and the like of the seventh icon unit 66G changes according to the reception sensitivity of the reception signal of the reception device 41.
In the above-described embodiment, the condition for permitting automatic steering is that the variation of a plurality of steering angles θn is within a predetermined range, but the direction of the tractor 1 (vehicle body 3) before automatic steering is the travel reference. It may be added that it is within a predetermined range with respect to the direction of the line L1. As shown in FIG. 9, in a situation where the tractor 1 (vehicle body 3) is traveling the determination distance J1 after the position P13, the second control device 60B is used when the variation of a plurality of steering angles θn is within a predetermined range. Allows automatic steering related to steering (first permission), and the direction F1 of the tractor 1 (vehicle body 3) calculated by the positioning device 40 or the like and the direction (extending direction) of the traveling reference line L1 are within a predetermined range. If this is the case, automatic steering regarding the direction is permitted (second permission). Then, the second control device 60B starts the automatic steering when the first permission and the second permission are aligned and the switching of the start of the automatic steering is performed by the operator.

The work vehicle 1 has a steering device 11 having a steering handle 30, a vehicle body 3 capable of traveling by either manual steering by the steering handle 30 or automatic steering of the steering handle 30 based on the travel reference line L1, and manual steering. It includes a control device 60B that permits automatic steering based on a plurality of steering angles of the steering device 11 when the vehicle body 3 travels a predetermined distance. According to this, under the situation where the work vehicle 1 is driven by manual steering, it is possible to shift from manual steering to automatic steering based on the state of a plurality of steering angles, that is, the transition of steering angles. It is possible to judge whether or not.

For example, as shown in FIG. 12, when the work vehicle 1 is traveling on a downward slope (the left side is high and the right side is low when viewed from the work vehicle 1), the steering of the steering device 11 is fixed to the left. It may go straight in the state of being. That is, when the steering device 11 is steered to the left, it turns to the left according to the steering direction on a flat ground, but goes straight on a slope, and the steering angle θ is relatively larger than that on a flat ground. A large state will continue in a row. As described above, in the case of a slope, even if the steering angle θ is larger than that on a flat ground and continuously continues, as described above, the automatic steering is determined at a plurality of steering angles θn, so that the work vehicle 1 In, it is possible to properly judge straight running not only on flat ground but also on sloped ground. As a result, the work vehicle 1 capable of stably traveling the work vehicle 1 when switching from manual steering to automatic steering is provided with a steering changeover switch 52 for switching between start and end of automatic steering, and is a control device. The 60B includes a steering angle acquisition unit 201 that acquires a plurality of steering angles, and a steering determination unit 202 that determines whether or not to permit the start of automatic steering based on the plurality of steering angles acquired by the steering angle acquisition unit 201. The automatic steering control unit 200 controls the steering device 11 to perform automatic steering when the steering changeover switch 52 switches the start of automatic steering while the steering determination unit 202 determines that the permission is granted. are doing. According to this, a plurality of steering angles at the time of manual steering can be acquired by the steering angle acquisition unit 201, and the steering determination unit 202 appropriately determines whether automatic steering may be performed based on the plurality of steering angles. Later, automatic steering can be performed by the automatic steering control unit 200.

The work vehicle 1 is provided with a display device 45 that indicates that the start of automatic steering is permitted by the steering determination unit 202. According to this, the operator can easily grasp whether or not the start of automatic steering is permitted only by looking at the display device 45.
The steering determination unit 202 permits the start of automatic steering when the variation of a plurality of steering angles is within a predetermined range. According to this, when the steering angle is stable, it is possible to properly switch from manual steering to automatic steering, that is, to start automatic steering.

The work vehicle 1 has a positioning device 40 capable of detecting the position of the vehicle body 3 and a reference line setting switch for setting the position of the vehicle body 3 detected by the positioning device 40 at the start position and the end position of the traveling reference line L1. I have. According to this, the traveling reference line L1 can be easily set by the reference line setting switch.
It should be considered that the embodiments disclosed this time are exemplary in all respects and not restrictive. The scope of the present invention is shown by the scope of claims rather than the above description, and is intended to include all modifications within the meaning and scope equivalent to the scope of claims.

1 Work vehicle 3 Body 11 Steering device 30 Steering handle 40 Positioning device 52 Steering changeover switch 60B Second control device (control device)
200 Automatic steering control unit 201 Steering angle acquisition unit 202 Steering judgment unit 205 Steering angle detection device L1 Driving reference line

Claims (6)

A steering device with a steering handle and
A vehicle body that can be driven by either manual steering by the steering wheel or automatic steering of the steering wheel that steers along the planned travel line set based on the travel reference line.
A steering angle detecting device provided on the vehicle body and detecting the steering angle of the steering device,
A control device that permits automatic steering based on a plurality of steering angles of the steering device when the vehicle body travels a predetermined distance in the manual steering.
A steering changeover switch for switching between start and end of the automatic steering in the scheduled travel line, which is not associated with the length of the travel reference line, is provided.
The control device is
After the position where the steering changeover switch is operated and the automatic steering is completed, in the turning section where the steering angle detected by the steering angle detecting device exceeds the turning determination steering angle, the steering angle detecting device is used. The steering angle detected by the steering angle is not acquired as the plurality of steering angles, and a predetermined determination distance or a predetermined steering angle is determined from a position where the steering angle detected by the steering angle detection device is equal to or less than the turning determination steering angle. A steering angle acquisition unit that acquires the steering angle detected by the steering angle detection device at predetermined time intervals as the plurality of steering angles within the determined determination time .
A steering determination unit that determines whether or not to allow the start of automatic steering based on a plurality of steering angles acquired by the steering angle acquisition unit, and a steering determination unit.
It has an automatic steering control unit that controls the steering device to perform automatic steering when the start switching of the automatic steering is performed by the steering changeover switch in a state of being determined to be permitted by the steering determination unit. Working vehicle . The steering determination unit obtains standard deviations and average values of the plurality of steering angles, and if all steering angles are within a predetermined value determined based on the standard deviations, the start of automatic steering is permitted, and one. The work vehicle according to claim 1, wherein when the steering angle of the unit is in a region exceeding a predetermined value determined based on the standard deviation, the start of automatic steering is not permitted. The work vehicle according to claim 1 or 2 , further comprising a display device indicating that the start of automatic steering is permitted by the steering determination unit. The work vehicle according to claim 2 or 3, wherein the steering determination unit permits the start of the automatic steering when the variation of the plurality of steering angles is within a predetermined range. A positioning device that can detect the position of the vehicle body and
A reference line setting switch that sets the position of the vehicle body detected by the positioning device to the start position and end position of the travel reference line, and
The work vehicle according to any one of claims 1 to 4 . When the variation of the plurality of steering angles is within a predetermined range, the steering determination unit performs the first permission to permit automatic steering related to steering, and the orientation of the vehicle body detected by the positioning device and the traveling reference line. If the azimuth is within a predetermined range, a second permission is given to allow automatic steering regarding the azimuth.
The automatic steering control unit performs the automatic steering when the steering changeover switch switches the start of the automatic steering in a state where the steering determination unit determines the first permission and the second permission. The work vehicle according to claim 5 to be started.

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