KR20200121224A - Work vehicle - Google Patents

Abstract

The object of the present invention is to perform automatic turning with simple control. A work vehicle according to an embodiment includes: driving wheels; a steering device; a motor; a position acquisition device; and a control device. The driving wheels are attached to a driving vehicle body. The steering device adjusts the steering amount of the driving wheels. The motor drives the steering device. The position acquisition device receives positioning information from a positioning means and acquires the current position information of the vehicle based on the received positioning information. The control device controls the motor. In addition, the control device has a first turning operation mode in which the motor is controlled and executed so that the steering amount can be a predetermined value regardless of the position information, and a second turning operation mode in which the motor is controlled and executed so that the vehicle can reach a desired orientation on a turning travel path based on the positioning information during turning of the vehicle.

Description

Work vehicle {WORK VEHICLE}

The present invention relates to a work vehicle.

BACKGROUND ART Conventionally, in a work vehicle that performs work while traveling on a pavement, there is one that acquires the position information of the work start position and the work end position, creates a reference line from the acquired position information, and automatically runs along the created reference line (for example, patent See document 1).

Japanese Patent Publication No. 2016-21890

In the work vehicle as described above, it is considered to automatically turn based on the acquired positional information. However, in the case of automatic turning, it is necessary to use the positional information throughout the turning stroke, thus complicating control.

The present invention has been made in view of the above, and an object of the present invention is to provide a work vehicle capable of automatically turning with simple control.

In order to solve the above-described problem and achieve the object, the working vehicle 1 described in claim 1 includes the running wheels 10 and 11 attached to the running body 2 and the steering amount of the running wheel 10. A position for receiving positioning information from the steering device 35 to be adjusted, the motor 95 for driving the steering device 35, and positioning means, and acquiring the current position information of the aircraft based on the received positioning information. An acquisition device 150 and a control device 100 for controlling the motor 95 are provided, and the control device 100 has a predetermined value regardless of the position information while the aircraft is turning. A first turning operation mode in which the motor 95 is controlled and executed, and the motor 95 is controlled and executed so that the aircraft reaches a desired orientation on the turning travel path L2 based on the position information. It characterized in that it has a second turning operation mode.

The work vehicle (1) according to claim 2 is the work vehicle (1) according to claim 1, wherein the control device (100) executes the first turning operation mode when the aircraft starts turning, and the first When the turning operation mode ends, the second turning operation mode is executed.

The work vehicle (1) according to claim 3, in the work vehicle (1) according to claim 1 or 2, further includes a detection device (90) for detecting the number of revolutions of the traveling wheel (11), The detection device 90 starts detection of the rotational speed at the start of the first rotational operation mode, and the control device 100 shifts to the second rotational operation mode when the rotational speed reaches a predetermined value. It features.

The work vehicle (1) according to claim 4 is the work vehicle (1) according to any one of claims 1 to 3, wherein the control device (100) runs the aircraft along a straight travel path (L1). It is characterized in that it has an automatic straight-forward mode to allow it to move, and shifts to the automatic straight-forward mode when the second turning operation mode toward the desired turning end position P2 is ended.

According to the invention described in claim 1, since the first turning operation mode is executed instead of the operation mode based on the position information while the aircraft is turning, it is not necessary to use the position information for the entire control according to the automatic turning, that is, During the automatic turning, the control using the location information may be part of the control, so that the automatic turning can be performed with simple control.

According to the invention described in claim 2, in addition to the effect of the invention described in claim 1, it is more simplified by executing the first turning operation mode when the aircraft starts turning and executing the second turning operation mode at the end of the turn. Automatic turning can be performed by control.

According to the invention described in claim 3, in addition to the effect of the invention described in claim 1 or 2, detection (counting) of the rotation speed of the running wheel is started upon the start of the first turning operation mode, and When the number of rotations reaches a predetermined value, the mode shifts to the second turning operation mode. As described above, the control using the position information during automatic turning may be partly performed, and automatic turning can be performed with simple control.

According to the invention according to claim 4, in addition to the effect of the invention according to any one of claims 1 to 3, the second turning operation mode toward the desired turning end position (the second turning operation while the aircraft is turning In the case of performing the mode twice or more, when the last second turning operation mode) ends, the automatic straight-line mode is shifted to the automatic straight-line mode as it is, so that the operation can be continuously performed and workability can be improved.

1 is a side view showing an example of a work vehicle.
2 is a plan view showing an example of a work vehicle.
3 is a block diagram showing a control system centered on a control device.
4 is an explanatory diagram of autonomous driving in pavement of a work vehicle.
5 is an explanatory diagram of automatic turning control according to the first embodiment.
6 is a flowchart showing a processing procedure of automatic turning control according to the first embodiment.
7 is a flowchart showing the processing procedure of control for starting automatic turning control.
Fig. 8 is a flowchart showing a control procedure for transitioning from the first turning operation mode to the second turning operation mode.
9 is an explanatory diagram of automatic turning control according to the second embodiment.
Fig. 10 is a flowchart showing a processing procedure of automatic turning control according to the second embodiment.
11 is an explanatory diagram of automatic turning control according to the third embodiment.
12 is a flowchart showing the processing procedure of automatic turning control according to the third embodiment.

Hereinafter, an embodiment of a work vehicle disclosed by the present application will be described in detail with reference to the accompanying drawings. In addition, the present invention is not limited by the embodiments shown below.

<Overview of work vehicle>

First, an outline of the work vehicle 1 according to the embodiment will be described with reference to FIGS. 1 and 2.

1 is a side (left side) view showing a work vehicle 1. 2 is a plan view showing the work vehicle 1.

In addition, in the following description, the front-rear direction is the advancing direction when the work vehicle 1 goes straight, and the front side of the advancing direction is defined as "front" and the rear side as "back". The traveling direction of the work vehicle 1 is a direction from the cockpit 41 toward the steering wheel 35 when going straight (see Figs. 1 and 2).

The left and right direction is a direction horizontally orthogonal to the front-rear direction, and the left and right are defined toward the "front" side. That is, in the state where the manipulator (also referred to as a worker) is seated in the cockpit 41 and faces forward, the left hand side is "left" and the right hand side is "right".

The vertical direction is a vertical direction. The forward and backward directions, the left and right directions, and the up and down directions are orthogonal to each other. Each direction is defined for convenience of description, and the present invention is not limited by these directions.

In addition, in the following description, the work vehicle 1 may be referred to as "gas." In the embodiment, the work vehicle is described as a passenger type seedling transplanter 1 that includes the seedling planting unit 4 as a work device and accepts seedlings on a package. As shown in Figs. 1 and 2, the seedling transplanter 1 includes an elevating and descending seedling planting part 4 (working device) for planting seedlings on a pavement through an elevating link mechanism 3 on the rear side of the traveling vehicle body 2. Equipped.

A body portion of the fertilizing device 5 is disposed above the rear portion of the traveling vehicle body 2. In addition, when the work vehicle is not the seedling transplanter 1, a sowing device for supplying seeds may be provided as a work device.

The running vehicle body 2 is a four-wheel drive vehicle having left and right front wheels 10 and rear wheels 11, which are running wheels and driving wheels. On the front side of the main frame 15 constituting the body frame of the traveling vehicle body 2, a transmission case 13 that transmits driving force to the seedling unit 4 and the like, and the driving force supplied from the engine 30, that is, the engine ( A hydraulic continuously variable transmission 14 (peripheral transmission mechanism) for outputting the rotation generated in 30) to the transmission case 13 is provided.

The continuously variable transmission 14 is a so-called hydrostatic transmission (HST) type continuously variable transmission. Hereinafter, a case where the continuously variable transmission is the HST 14 will be described.

In the mission case 13, an auxiliary transmission mechanism 16 is provided for switching the traveling mode of the traveling vehicle body 2 during road running in a high-speed mode or seedling planting in a low-speed mode.

Front wheel final cases 10a are installed on the left and right sides of the transmission case 13, and front wheels on the left and right front axles 10b protruding outward from the front wheel support portions capable of changing the steering direction of the left and right front wheel final cases 10a. (10) is attached.

In addition, on the rear side of the main frame 15, rear wheel gear cases 11a are attached to both left and right sides of the rear frame 22 (see Fig. 2) installed in the transverse direction of the aircraft, and from the rear wheel gear cases 11a to the outward side, respectively. Rear wheels 11 (running wheels) are attached to the protruding left and right rear axles 11b, respectively.

Further, on the upper part of the rear frame 22, left and right link support frames 23 for supporting the elevating link mechanism 3 protrude upward. A pair of left and right lower link arms 24 are provided on the lower side of the left and right link support frames 23 and between the left and right. A lifting cylinder 25 (elevating device) operated by hydraulic pressure is provided between the left and right of the left and right lower link arms 24.

An upper link arm 26 is provided above the lifting cylinder 25, and a lifting link mechanism 3 which is a parallel link mechanism is configured. In addition, the left and right lower link arms 24 with one end connected to the running vehicle body 2 side, the lifting cylinder 25, and the other end side of the upper link arm 26 are attached to the front of the seedling section 4 do.

Also, the engine 30 is mounted on the main frame 15. The rotational power of the engine 30 is transmitted to the transmission case 13 through the belt transmission device 21 and the HST 14. After the rotational power transmitted to the transmission case 13 is shifted by the auxiliary transmission mechanism 16 in the transmission case 13, it is divided into a traveling power and an external pull-out power.

In addition, the rotational power of the engine 30 is transmitted to a hydraulic pump, not shown. The hydraulic pressure generated by the hydraulic pump is supplied to the HST 14, the power steering mechanism 88 of the handle 35 (see FIG. 3), the lifting cylinder 25, and the like.

The external withdrawal power drawn from the rotational power transmitted to the transmission case 13 is transmitted to the planting clutch case 27 installed in the rear portion of the traveling vehicle body 2, and the planting transmission shaft 67 from the planting clutch case 27 It is transmitted to the seedling couple part 4 by this.

On the other hand, left and right drive shafts 42 are installed at the rear portion of the transmission case 13. The rotational power from the engine 30 is transmitted to the left and right rear gear cases 11a through the transmission case 13 and the drive shaft 42.

Further, a side clutch 44 (see Fig. 3) for turning on and off power transmission to the left and right drive shafts 42 is disposed above the left and right drive shafts 42 in the transmission direction. As shown in Fig. 1, a side clutch pedal 43a for turning on and off the left and right side clutches 44 is provided in the lower front side of the cockpit 41 and on one left and right side.

Of the side clutch pedals 43a on the left and right, when the side clutch 44 is turned off by stepping on the side clutch pedal 43a on the inside of the swing, and then the steering wheel 35 is operated to swing, the rear wheel 11 on the inside of the swing It can completely block the drive rotation of the.

As a result, the turning radius can be made smaller than that of turning travel by operating the handle 35 alone, and it is possible to appropriately select the operation start position of the working group suitable for the packaging conditions, thereby improving work precision.

In this way, the turning radius can be reduced by stopping the transmission to the rear wheel 11 inside the turning during turning, and since the working position of turning and the working position after turning can be prevented from becoming distant, the working position after turning can be Operation of re-adjustment becomes unnecessary, and work efficiency and work precision are improved.

In addition, in the embodiment, in the automatic turning control to be described later, when the driving vehicle body 2 is turned by the operation of the handle 35, the side clutch 44 located inside the turning is turned off, and the rear wheel inside the turning is turned off. It is configured to stop the transmission to (11).

A bonnet 39 in which a control panel 38 for operating each part is disposed is installed in an upper portion of the front side of the traveling vehicle body 2. The control panel 38 is provided with an automatic turning switch 48, a monitor 86 (refer to Fig. 3) and the like for switching whether or not automatic turning control described later is to be performed.

In addition, the bonnet 39 has a handle 35 for steering the aircraft, a shift operation lever 36 for operating the HST 14 or the seedling unit 4, and an auxiliary shift operation lever for operating the auxiliary transmission mechanism 16 ( 37) Light is installed.

In addition, a front cover 40 capable of opening and closing is provided on the front side of the bonnet 39. In the interior of the front cover 40, an interlocking mechanism for rotating the lower side of the left and right front wheels 10 and the left and right front wheel final cases 10a in response to steering of the fuel tank, battery, and handle 35 is provided.

The engine cover 30a is installed at the rear side of the aircraft than the bonnet 39, and covers the upper and side portions of the engine 30 at an upper position of the engine 30, and the operator is seated at the upper part of the engine cover 30a. The cockpit 41 is installed.

It is the rear side of the cockpit 41, and the fertilization apparatus 5 is installed at the rear end side of the main frame 15. The driving force of the fertilization apparatus 5 is transmitted by a fertilization transmission mechanism provided so as to face the fertilization apparatus 5 from the left and right one side of the left and right rear wheel gear cases 11a.

By the way, the floor steps 33 which are substantially horizontal are formed on both left and right sides in the lower part of the engine cover 30a and the bonnet 39. As shown in FIG. 2, the floor step 33 has a partial lattice shape. For example, even if mud adhered to the shoes of an operator walking on the floor step 33 falls, the fallen mud or the like falls on the pavement.

Further, as shown in FIG. 1, the seedling transplanter 1 includes a position acquisition device 150. The position acquisition device 150 receives positioning information from positioning means such as GPS (Global Positioning System) or GNSS (Global Navigation Satellite System), and creates and acquires current position information of the aircraft based on the received positioning information. do. The position acquisition device 150 is attached to the attachment stay 59, for example, and is disposed above the traveling vehicle body 2.

The program for straightening control and the program for turning control, which are created based on the positional information by the position acquisition device 150, are stored in separate places. The program for linear movement control is stored in, for example, an electronic control unit (ECU) 100a for linear movement control in the position acquisition device 150, and the program for swing control is, for example, the ECU 100b for swing control housed in the bonnet 39. Is stored in. Moreover, the ECU 100a for straight-line control and the ECU 100b for turning control are included in the control apparatus 100 (refer FIG. 3) mentioned later.

<Control system of work vehicle>

Next, the control system C of the seedling transplanter 1 will be described with reference to FIG. 3. 3 is a block diagram showing a control system C centered on the control device 100 in the seedling transplanter 1. The seedling transplanter 1 is capable of controlling each unit by electronic control, and includes a control device (hereinafter referred to as a controller) 100 for controlling each unit.

The controller 100 is provided with a processing unit having a CPU (Central Processing Unit), a memory unit such as ROM (Read Only Memory) and RAM (Random Access Memory), and an input/output unit, which are connected to each other to exchange signals with each other. This is possible. A computer program for controlling the seedling transplanter 1 is stored in the storage unit. The controller 100 exerts each function by reading a computer program or the like stored in the storage unit.

The controller 100 includes, for example, a throttle motor 80 as actuators, a hydraulic control valve 81, 82, a planting clutch operation solenoid 83, a side clutch operation solenoid 84, an HST motor 85, and a line. A drawing marker lifting motor 87, a steering motor 95, and the like are connected.

The throttle motor 80 increases or decreases the number of revolutions of the output shaft of the engine 30 by operating a throttle that adjusts the intake air amount of the engine 30. The hydraulic control valve 81 controls the expansion and contraction operation of the lifting cylinder 25. The hydraulic control valve 82 controls the power steering mechanism 88. The planting clutch operation solenoid 83 operates the planting clutch 27a.

The side clutch operation solenoid 84 operates the side clutch 44 for switching the power transmission state to the rear wheels 11. In addition, side clutches 44 are provided on the left and right rear wheels 11 respectively, and two side clutch operation solenoids 84 are provided corresponding to each side clutch 44.

The HST motor 85 changes the inclination angle of the swash plate of the HST 14 by changing the rotation angle of the tranion of the HST 14. The steering motor 95 is a motor that drives the steering wheel 35 as a steering device that adjusts the steering amount (steering angle) of the front wheel 10 (see Fig. 1) as a traveling wheel when automatic turning control is performed. The steering motor 95 rotates the steering wheel 35. The line drawing marker lifting motor 87 raises and lowers the line drawing marker 65.

Further, the controller 100 is connected with a rotation speed sensor 90, a steering amount sensor 91, an inclination sensor 92, etc. which are detection devices. Two rotation speed sensors 90 are provided corresponding to the left and right rear wheels 11 which are traveling wheels, and each detect the rotation speed of the left and right rear wheels 11. Further, the rotation speed sensor 90 may detect the rotation speed of the left and right front wheels 10.

The steering amount sensor 91 detects an operation amount of the steering wheel 35 which is a steering device, that is, a steering amount (steering angle) of the front wheel 10. Further, the steering amount is detected in each of the left and right directions on the basis of the case where the operation amount of the steering wheel 35 is zero, that is, when the traveling vehicle body 2 is traveling straight ahead. The inclination sensor 92 detects an inclination angle that is the inclination of the traveling vehicle body 2.

In addition, as an operation signal to the controller 100, a shift operation lever 36, an auxiliary shift operation lever 37, a planting part automatic lifting switch 47, an automatic turning switch 48, a line drawing marker automatic lifting switch 49, etc. The signal is input from

The planting part automatic raising/lowering switch 47 is a switch for switching whether or not the seedling planting part 4 is automatically raised or lowered in conjunction with the operation amount of the handle 35, that is, the steering amount of the front wheel 10. When the planting part automatic raising/lowering switch 47 is "on", control is executed to automatically lift the seedling planting part 4 in association with the steering amount. On the other hand, when the planting part automatic lifting switch 47 is "off", control for automatically lifting the seedling planting part 4 in association with the steering amount is not executed.

The line drawing marker automatic lift switch 49 is a switch for switching whether or not the line drawing marker 65 is automatically lifted or lowered in association with the operation amount of the handle 35, that is, the steering amount of the front wheel 10. When the line drawing marker automatic lifting switch 49 is "ON", control is executed to automatically raise and lower the line drawing marker 65 in association with the steering amount. On the other hand, when the line drawing marker automatic lifting switch 49 is "off", the control for automatically lifting the line drawing marker 65 in association with the steering amount is not executed.

The automatic turning switch 48 is a bounce switch with a lamp, and is a switch for switching whether to start or stop the automatic turning. The automatic turning switch 48 is turned "on" by the operator and is turned on while the automatic turning is being performed. When the automatic turning is finished, it turns "off" and turns off. Further, the automatic turning switch 48 is turned "off" by the operator during automatic turning, and turns off when the automatic turning is stopped. This makes it possible for the operator to recognize whether or not automatic turning is being performed.

In addition, the current position information of the aircraft is input to the controller 100 from the position acquisition device 150. The controller 100 executes an autonomous driving mode in which the aircraft automatically travels and performs tasks based on the location information. With the controller 100 as the center, the automatic turning switch 48, the rotation speed sensor 90, the steering amount sensor 91, the steering motor 95, the steering wheel 35, and the position acquisition device 150 are automatic to be described later. It constitutes the control system C of the turning mode.

<Autonomous driving mode>

Here, with reference to FIG. 4, the automatic running (autonomous running) including the automatic turning in the pavement by the seedling transplanter 1 is demonstrated. Fig. 4 is an explanatory view of autonomous driving in the pavement of a work vehicle (seedling transplanter 1). The controller 100 (see Fig. 3) controls the steering motor 95 (see Fig. 3) while feeding back the steering amount of the front wheel 10 (see Fig. 1) to manipulate the steering wheel 35 (see Fig. 3). It has an autonomous driving mode. The autonomous driving mode includes an automatic straight forward mode and an automatic turning mode.

As shown in FIG. 4, in the autonomous driving mode, the seedling transplanter 1 automatically performs a seedling planting operation in the pavement F, repeating straight forward and turning along a predetermined travel route. Further, the controller 100 acquires the current position information of the seedling transplanter 1 by the position acquisition device 150 disposed above the traveling vehicle body 2 as described above.

The seedling transplanter 1 performs seedling planting while reciprocating within a predetermined work area in the package F. In this case, for straight travel, the controller 100 performs automatic driving along the set straight travel path L1 by executing the automatic straight travel mode. In addition, for turning travel, the controller 100 performs an automatic turning along the set turning travel path L2 by executing the automatic turning mode.

The straight travel path L1 is parallel to the reference line L0 serving as a driving reference. The reference line L0 is set in the packaging F according to the planting direction of the seedling. The controller 100 acquires a start position and an end position of the straight traveling as a reference point (point A) and a reference end point (point B), respectively, and registers a line segment connecting points A and B as a reference line L0.

In addition, the controller 100 has a first turning operation mode and a second turning operation mode as an automatic turning mode. The controller 100 executes as an automatic turning mode by combining the first turning operation mode and the second turning operation mode. Further, the controller 100 executes the automatic turning mode when the automatic turning switch 48 is "on" by the operator.

In the first turning operation mode, the controller 100 controls the steering motor 95 so that the steering amount of the steering wheel 35 becomes a predetermined value while the seedling transplanter 1 is turning. In this case, the controller 100 executes the processing regardless of the position information acquired by the position acquisition device 150.

In the second turning operation mode, the controller 100 moves the seedling transplanter to a desired position on the turning travel path L2 based on the position information acquired by the position acquisition device 150 while the seedling transplanter 1 is turning. The steering motor 95 is controlled so that (1) is reached.

In this way, since the controller 100 has a first turning operation mode and a second turning operation mode, and executing the first turning operation mode instead of the operation mode based on position information while the aircraft is turning, the entire control according to automatic turning There is no need to use location information. For this reason, the control using the positional information during the automatic turning may be partly performed, and the automatic turning can be performed with simple control.

In addition, in the automatic turning mode, when the controller 100 deviates from the turning travel path L2 during turning of the seedling transplanter 1 and turns (largely rotates or rotates small), the position acquisition device 150 is Correction is made based on the acquired location information.

<Automatic turning mode according to the first embodiment>

Next, an automatic turning mode according to the first embodiment will be described with reference to FIGS. 5 to 8. 5 is an explanatory diagram of automatic turning control (automatic turning mode) according to the first embodiment. 6 is a flowchart showing a processing procedure of automatic turning control (automatic turning mode) according to the first embodiment.

7 is a flowchart showing the processing procedure of control for starting the automatic turning control (automatic turning mode). Fig. 8 is a flowchart showing a control procedure for transitioning from the first turning operation mode to the second turning operation mode.

As shown in Fig. 5, in the automatic turning mode according to the first embodiment, the seedling transplanter 1, which has been proceeding in the automatic straight forward mode, has a predetermined desired turning start position (in the case of agricultural machinery such as the seedling transplanter 1, in the first set It is also a work end position) When the automatic turning switch 48 (refer FIG. 3) is pressed by the operator at a position close to P1, automatic turning is started.

Upon starting the automatic turning, the seedling transplanter 1 starts progressing according to the first turning operation mode. In the first turning operation mode, the seedling transplanter 1 proceeds along the turning travel path L2, and proceeds by the first turning operation mode at the end position (mode end position) P3 on the turning travel path L2. It ends. When the seedling transplanter 1 ends the progression by the first turning operation mode, the seedling transplanter 1 starts the progression by the second turning operation mode.

In the second turning operation mode, the seedling transplanter 1 runs straight forward in the next group in the predetermined desired turning end position (in the case of agricultural machinery such as the seedling transplanter 1, it is also the work start position in the next group) (P2). Progress (straight forward) while gradually correcting the position so as to follow the path L1, and when the progress by the second turning operation mode is ended, the progress in the next group is started in the automatic straight forward mode.

As shown in Fig. 6, in the first embodiment, the controller 100 determines whether or not the automatic turning switch 48 has been operated "on" (step S101). When the automatic turning switch 48 is operated "on" (step S101: Yes), the controller 100 determines whether or not the seedling transplanter 1 has reached the turning start position P1 (step S102). When the controller 100 determines that the turning start position P1 has been reached (step S102: Yes), it starts execution of the first turning operation mode (step S103).

When the automatic turning switch 48 is not operated "on" in the processing of (step S101) (step S101: No), the controller 100 repeats the processing taken until the "on" operation is performed. In addition, in the processing of (step S102), when the seedling transplanter 1 has not reached the turning start position P1 (step S102: No), it takes until it reaches the turning start position P1. The treatment is repeated.

Next, the controller 100 determines whether or not the seedling transplanter 1 has reached the end position (mode end position) P3 of the first turning operation mode (step S104). When the controller 100 reaches the mode end position P3 (step S104: Yes), it ends the execution of the first turning operation mode (step S105), and starts execution of the second turning operation mode (step S106). ).

When the seedling transplanter 1 has not reached the mode end position P3 in the process of (Step S104) (Step S104: No), the processing taken until the mode end position P3 is reached Repeat.

Next, the controller 100 determines whether or not the seedling transplanter 1 has reached the turning end position P2 which is also the end position of the second turning operation mode (step S107). When the controller 100 reaches the turning end position P2 (step S107: Yes), it ends the execution of the second turning operation mode (step S108), and ends the turning operation mode.

Here, in the first turning operation mode, in the first turning operation mode, for example, the steering motor 95 ( 3). When the direction of the aircraft is 70 degrees, the controller 100 controls the steering motor 95 to start returning to straight travel, that is, so that the direction of the aircraft is 90 degrees.

When the controller 100 shifts from the first turning operation mode to the second turning operation mode, the steering motor (or the steering motor 100) so that the direction of the aircraft falls within the range of, for example, 0 to 20 degrees for the straight traveling path L1 of the next set. 95). The controller 100 allows the direction of the aircraft to fall within the range of 0 to 20 degrees at the start of the second turning operation mode, so that the position acquisition device 150 (see Fig. 3) acquires position information in the second turning operation mode. Based on this, the direction of the aircraft is corrected to follow the straight travel path L1 to complete the turning operation.

In the case where the seedling transplanter 1 has not reached the turning end position P2 in the processing of (Step S107) (Step S107: No), the processing taken until it reaches the turning end position P2 Repeat. When the controller 100 ends the turning operation mode, it starts execution of the automatic straight forward mode.

In addition, as shown in FIG. 7, in the processing of (step S101) shown in FIG. 6, the controller 100 is in progress in the automatic straight-line mode, based on the positional information acquired by the position acquisition device 150, of the seedling transplanter 1 It is determined whether or not the distance from the current position to the turning start position P1 is equal to or less than a predetermined distance D (step S1011). The controller 100 calculates the travel distance based on the positioning information, and determines whether the distance from the current position of the seedling transplanter 1 to the turning start position P1 is less than or equal to a predetermined distance D. Further, the controller 100 may calculate the travel distance based on the rotation speed of the driving wheel.

The controller 100 makes the above determination based on the travel distance in the preceding step, which is the planting step one earlier than the planting step at the time of the current straight travel.

It can be predicted that the turning start position P1 in this planting process is the mileage in the preceding process in this planting process, and the vicinity which advanced. For example, in this planting process, the position where the turn is actually started can be predicted to be within a range of about ±5m with respect to the mileage in the preceding process.

Therefore, the controller 100 predicts the turning start position P1 based on the travel distance in the preceding step. Specifically, the controller 100 predicts the position at which the distance traveled straight in the current planting process becomes the travel distance in the preceding process as the turning start position P1, and starts turning from the current position of the seedling transplanter 1 When the distance to the position P1 is equal to or less than the predetermined distance D, it is determined that it is near the turning position, that is, the headland.

Further, the turning start position P1 may be recognized by coordinates based on the positioning information.

The controller 100 executes the first turning operation mode when the distance to the turning start position P1 is less than or equal to the predetermined distance D (step S1011: Yes), when the automatic turning switch 48 is operated "on". Do (step S1012).

When the distance to the turning start position P1 exceeds a predetermined distance D in the processing of (step S1011) (step S1011: No), the automatic turning switch 48 is turned "on". Even if it is operated, the first turning operation mode is not executed (step S1013), and the automatic straight forward mode is continued.

In addition, the end position P3 of the first turning operation mode is set based on the number of revolutions of the rear wheels 11 (see Fig. 1) detected (counted) by the number of revolutions sensor 90 (see Fig. 3). As shown in Fig. 8, when the execution of the first turning operation mode is started in the processing of (step S103) shown in Fig. 6, the controller 100 starts counting the number of revolutions of the rear wheels 11 according to this. (Step S1031), it is determined whether or not the rotation speed of the rear wheel 11 has reached a predetermined value (count value) (Step S1032).

When the number of rotations of the rear wheels 11 reaches a predetermined count value (step S1032: Yes), the controller 100 determines that the end position P3 has been reached, ends the execution of the first turning operation mode, and ends the second The turning operation mode is executed (step S1033). When the rotation speed of the rear wheel 11 is not a predetermined count value in the processing of (step S1032) (step S1032: No), the controller 100 repeats the processing taken until the predetermined count value is reached.

According to the first embodiment described above, by executing the first turning operation mode at the start of turning of the seedling transplanter 1 and executing the second turning operation mode at the end of turning, automatic turning can be performed with simpler control. I can.

In addition, counting of the number of revolutions of the rear wheels 11 is started upon the start of the first turning operation mode, and when the number of revolutions of the rear wheels 11 reaches a predetermined count value, the mode shifts to the second turning operation mode. It is possible to perform automatic turning with simple control because it may be part of the control using the.

In addition, when the distance from the current position of the seedling transplanter 1 to the turning start position P1 is short, the first turning operation mode is executed when the automatic turning switch 48 is operated "on". On the other hand, when the distance from the current position of the seedling transplanter 1 to the turning start position P1 is long, the first turning operation mode is not executed even if the automatic turning switch 48 is operated. In this way, for example, even if the automatic turning switch 48 is operated (i.e., erroneously operated) outside the turning start position P1 near the center of the pavement, it is possible to prevent misoperation by not executing the first turning operation mode. I can.

In addition, when the second turning operation mode toward the turning end position P2 ends, the automatic straight forward mode is shifted to the automatic straight forward mode and the automatic straight forward is started, so that the work can be continued and workability can be improved.

In addition, in the first embodiment, the first turning operation mode is executed and then the second turning operation mode is executed, but as a modification, for example, after executing the second turning operation mode, the first turning operation mode is executed. You may reach the turning end position P2.

<Automatic turning mode according to the second embodiment>

Next, an automatic turning mode according to the second embodiment will be described with reference to Figs. 9 and 10. 9 is an explanatory diagram of automatic turning control (automatic turning mode) according to the second embodiment. Fig. 10 is a flowchart showing a processing procedure of automatic turning control (automatic turning mode) according to the second embodiment.

As shown in Fig. 9, in the automatic turning mode according to the second embodiment, as in the first embodiment, the seedling transplanter 1, which has been proceeding in the automatic straight forward mode, is placed in a position close to the preset desired turning start position P1. When the automatic turning switch 48 (refer to FIG. 3) is depressed by this, automatic turning is started.

When the automatic turning is started, the seedling transplanter 1 starts to proceed according to the second turning operation mode (first time), and proceeds along the turning travel path L2. The seedling transplanter 1 ends the progression by the first second turning operation mode at the end position (mode end position) P4 on the turning travel path L2.

When the seedling transplanter 1 finishes the progress by the 1st 2nd rotation operation mode, it starts the progress by the 1st rotation operation mode. The seedling transplanter 1 ends the progression by the first turning operation mode at the mode end position P5 on the turning travel path L2. When the seedling transplanter 1 finishes the progress in the first turning operation mode, the seedling transplanter 1 starts the progress in the second turning operation mode (second time) again.

In the second second turning operation mode, the seedling transplanter 1 proceeds (go straight) while gradually correcting the position to follow the straight travel path L1 of the next group at the preset desired turning end position P2. When the progress by the second turning operation mode of is ended, the progress in the next group is started in the automatic straight forward mode.

As shown in Fig. 10, in the second embodiment, the controller 100 determines whether or not the automatic turning switch 48 is operated "on" (step S201). When the automatic turning switch 48 is operated "on" (step S201: Yes), the controller 100 determines whether or not the seedling transplanter 1 has reached the turning start position P1 (step S202). If the controller 100 determines that the turning start position P1 has been reached (step S202: Yes), it starts execution of the second turning operation mode (first time) (step S203).

When the automatic turning switch 48 is not operated "on" in the processing of (step S201) (step S201: No), the controller 100 repeats the processing taken until the "on" operation is performed. In addition, in the processing of (Step S202), when the seedling transplanter 1 has not reached the turning start position P1 (Step S202: No), it takes until it reaches the turning start position P1. The treatment is repeated.

Next, the controller 100 determines whether or not the seedling transplanter 1 has reached the end position (mode end position) P4 of the first second turning operation mode (step S204). When the controller 100 reaches the mode end position P4 (step S204: Yes), it ends the execution of the first second turning operation mode (step S205), and starts execution of the first turning operation mode. (Step S206).

In the case where the seedling transplanter 1 has not reached the mode end position P4 in the processing of (Step S204) (Step S204: No), the processing taken until the mode end position P4 is reached Repeat.

Subsequently, the controller 100 determines whether or not the seedling transplanter 1 has reached the end position (mode end position) P5 of the first turning operation mode (step S207). When the controller 100 reaches the mode end position P5 (step S207: Yes), it ends the execution of the first turning operation mode (step S208), and starts execution of the second turning operation mode (second time). (Step S209).

When the seedling transplanter 1 has not reached the mode end position P5 in the process of step S207 (Step S207: No), the controller 100 repeats the processing taken until it reaches the mode end position P5. do.

Subsequently, the controller 100 determines whether or not the seedling transplanter 1 has reached the turning end position P2 which is also the end position of the second second turning operation mode (step S210). When the controller 100 reaches the turning end position P2 (step S210: Yes), the execution of the second second turning operation mode is terminated (step S211), and the turning operation mode is terminated.

When the seedling transplanter 1 has not reached the turning end position P2 in the processing of (Step S210) (Step S210: No), the processing taken until it reaches the turning end position P2 Repeat. When the controller 100 ends the turning operation mode, it starts execution of the automatic straight forward mode.

Here, when the controller 100 shifts from the first turning operation mode to the second second turning operation mode, the direction of the aircraft is in the range of, for example, 0 to 20 degrees with respect to the straight traveling path L1 of the next set. The steering motor 95 is controlled to enter the inside. The controller 100 makes the direction of the aircraft within the range of 0 to 20 degrees at the start of the second second turning operation mode, so that the position acquisition device 150 in the second second turning operation mode (see Fig. 3) The direction of the aircraft is corrected so as to follow the straight travel path L1 based on the positional information acquired by the vehicle to complete the turning operation.

Also in the second embodiment, similarly to the first embodiment, in the processing of (step S201) shown in FIG. 10, the controller 100 is in progress by the automatic straight-line mode, the position acquisition device 150 (see FIG. 3). ), it is determined whether or not the current position of the seedling transplanter 1 is equal to or less than the predetermined distance D from the turning start position P1.

When the distance to the turning start position P1 is less than or equal to the predetermined distance D, the controller 100 executes the first second turning operation mode when the automatic turning switch 48 is operated "on".

The controller 100 does not execute the first turning operation mode when the distance to the turning start position P1 exceeds the predetermined distance D, even if the automatic turning switch 48 is operated "on". Continue straight mode.

Also in the second embodiment, as in the first embodiment, the end position P5 of the first turning operation mode is the rear wheel 11 (see Fig. 1) counted by the rotation speed sensor 90 (see Fig. 3). ) Is set based on the number of rotations. When the controller 100 starts execution of the first turning operation mode in the processing of (step S206) shown in FIG. 10, it starts counting the number of revolutions of the rear wheels 11 according to this, and the rear wheels 11 It is determined whether or not the number of revolutions of is reached a predetermined count value.

When the number of rotations of the rear wheels 11 reaches a predetermined count value, the controller 100 determines that the mode end position P5 has been reached, ends the execution of the first turning operation mode, and a second turning operation. Run the mode. When the number of rotations of the rear wheels 11 is not a predetermined count value, the controller 100 repeats the processing taken until the predetermined count value is reached.

According to the second embodiment described above, the first turning operation mode is executed at the start of turning of the seedling transplanter 1, and the second turning operation mode is executed at the end of turning, so that automatic turning can be performed with simpler control. have.

In addition, since the first turning operation mode is executed when the aircraft goes straight during the turning after the end of the first second turning operation mode, it is possible to reduce a running error due to slip of the rear wheels 11 in the first turning operation mode. Automatic turning can be accurately performed as a whole of the turning stroke.

In addition, counting of the number of revolutions of the rear wheels 11 is started upon the start of the first turning operation mode, and when the number of revolutions of the rear wheels 11 reaches a predetermined count value, the automatic turning operation mode is shifted to the second turning operation mode. The control using the location information may be part of the inside, so that automatic turning can be performed with simple control.

In addition, when the distance from the current position of the seedling transplanter 1 to the turning start position P1 is short, the first turning operation mode is executed when the automatic turning switch 48 is operated "on". On the other hand, when the distance from the current position of the seedling transplanter 1 to the turning start position P1 is long, the first turning operation mode is not executed even if the automatic turning switch 48 is operated. In this way, for example, even if the automatic turning switch 48 is operated (i.e., mis-operated) outside the turning start position P1, such as near the center of the pavement, the first turning operation mode is not executed to prevent misoperation. I can.

In addition, when the second second turning operation mode toward the turning end position P2 is ended, the automatic straight forward mode is shifted to the automatic straight forwarding mode and the automatic straight forwarding is started, so that the work can be continuously performed and workability can be improved.

Further, in the second embodiment, after executing the second turning operation mode, the first turning operation mode is executed, and then the second turning operation mode is again executed. As a modified example, for example, the first turning operation mode is executed. After that, the second turning operation mode may be executed, and the first turning operation mode may be executed again to reach the turning end position P2.

Further, the first turning operation mode and the second turning operation mode may be set as an automatic turning mode in which each is executed two or more times.

<Automatic turning mode according to the third embodiment>

Next, an automatic turning mode according to the third embodiment will be described with reference to Figs. 11 and 12. Fig. 11 is an explanatory diagram of automatic turning control (automatic turning mode) according to the third embodiment. Fig. 12 is a flowchart showing a processing procedure of automatic turning control (automatic turning mode) according to the third embodiment.

As shown in Fig. 11, the third embodiment is an automatic turning mode in the case of a so-called back turn of a dead end, in which the seedling transplanter 1 advances to the headland and turns after a predetermined distance backwards.

In the automatic turning mode according to the third embodiment, when the shift operation lever (referred to as HST lever) 36 (refer to Fig. 3) is operated to the reverse side of the seedling transplanter 1 that has advanced from the automatic straight mode to the headland, The work line in the next group (the turning travel path L2 and the straight travel path L1 of the next group) is acquired, and automatic turning including a reverse operation is started.

When the automatic turning is started, the seedling transplanter 1 moves backward by a predetermined distance, starts to proceed in the second turning operation mode (first time), and proceeds along the turning travel path L2. The seedling transplanter 1 ends the progression by the first second turning operation mode at the end position (mode end position) P6 on the turning travel path L2.

When the seedling transplanter 1 finishes the progress by the 1st 2nd rotation operation mode, it starts the progress by the 1st rotation operation mode. The seedling transplanter 1 ends the progression by the first turning operation mode at the mode end position P7 on the turning travel path L2. When the seedling transplanter 1 finishes the progress in the first turning operation mode, the seedling transplanter 1 starts the progress in the second turning operation mode (second time) again.

In the second second turning operation mode, the seedling transplanter 1 proceeds (go straight) while gradually correcting the position to follow the straight travel path L1 of the next group at the preset desired turning end position P2. When the progress by the second turning operation mode of is ended, the progress in the next group is started in the automatic straight forward mode.

As shown in Fig. 12, in the third embodiment, the controller 100 determines whether or not the HST lever 36 has been operated to the "reverse" side (step S301). When the HST lever 36 is operated to the "reverse" side (step S301: Yes), the controller 100 starts the retraction of the seedling transplanter 1 (step S302).

The controller 100 determines whether or not the seedling transplanter 1 has reached the turning start position P1 (step S303). If the controller 100 determines that the turning start position P1 has been reached (Step S303: Yes), the reversing of the seedling transplanter 1 is terminated (Step S304), and execution of the second turning operation mode (first time) is performed. It starts (step S305).

When the HST lever 36 is not operated to the "reverse" side in the process of (step S301) (step S301: No), the controller 100 repeats the processing taken until it is operated to the "reverse" side. In addition, in the processing of (Step S303), when the seedling transplanter 1 has not reached the turning start position P1 (Step S303: No), it takes until it reaches the turning start position P1. The treatment is repeated.

Next, the controller 100 determines whether the seedling transplanter 1 has reached the end position (mode end position) P6 of the first second turning operation mode (step S306). When the controller 100 reaches the mode end position P6 (step S306: Yes), it ends the execution of the first second turning operation mode (step S307), and starts execution of the first turning operation mode. (Step S308).

In the case where the seedling transplanter 1 has not reached the mode end position P5 in the processing of (Step S306) (Step S306: No), the processing taken until the mode end position P6 is reached. Repeat.

Subsequently, the controller 100 determines whether or not the seedling transplanter 1 has reached the end position (mode end position) P7 of the first turning operation mode (step S309). When the controller 100 reaches the mode end position P7 (step S309: Yes), it ends the execution of the first turning operation mode (step S310), and starts execution of the second turning operation mode (second time). (Step S311).

When the seedling transplanter 1 has not reached the mode end position P7 in the processing of (Step S309) (Step S309: No), the processing taken until the mode end position P7 is reached Repeat.

Next, the controller 100 determines whether or not the seedling transplanter 1 has reached the turning end position P2 which is also the end position of the second second turning operation mode (step S312). When the controller 100 reaches the turning end position P2 (step S312: Yes), the execution of the second second turning operation mode is terminated (step S313), and the turning operation mode is terminated.

In the case where the seedling transplanter 1 has not reached the turning end position P2 in the processing of (Step S312) (Step S312: No), the processing taken until it reaches the turning end position P2 Repeat. When the controller 100 ends the turning operation mode, it starts execution of the automatic straight forward mode.

Here, when the controller 100 shifts from the first turning operation mode to the second second turning operation mode, the direction of the aircraft is in the range of, for example, 0 to 20 degrees with respect to the straight traveling path L1 of the next set. The steering motor 95 is controlled to enter the inside. The controller 100 makes the direction of the aircraft within the range of 0 to 20 degrees at the start of the second second turning operation mode, so that the position acquisition device 150 in the second second turning operation mode (see Fig. 3) The direction of the aircraft is corrected so as to follow the straight travel path L1 based on the positional information acquired by the vehicle to complete the turning operation.

Also in the third embodiment, as in the first and second embodiments, the end position P7 of the first turning operation mode is the rear wheel 11 ( 1)). When the controller 100 starts execution of the first turning operation mode in the processing of (step S308) shown in Fig. 12, it starts counting the rotation speed of the rear wheels 11 according to this, and the rear wheels 11 It is determined whether or not the number of revolutions of is reached a predetermined count value.

When the number of rotations of the rear wheels 11 reaches a predetermined count value, the controller 100 determines that the mode end position P7 has been reached, terminates the execution of the first turning operation mode, and the second turning operation of the second time. Run the mode. When the number of rotations of the rear wheels 11 is not a predetermined count value, the controller 100 repeats the processing taken until the predetermined count value is reached.

In addition, the controller 100 determines whether or not the turning start position P1 has been reached based on the number of revolutions of the rear wheels 11, which are traveling wheels, even in reverse travel at the initial stage of the turning operation.

According to the third embodiment described above, as in the first and second embodiments, the first turning operation mode is executed at the start of turning of the seedling transplanter 1, and the second turning operation mode is executed at the end of turning. Automatic turning can be performed with simpler control.

In addition, since the first turning operation mode is executed when the aircraft goes straight during the turning after the end of the first second turning operation mode, it is possible to reduce a running error due to slip of the rear wheels 11 in the first turning operation mode. As a whole, the automatic turning can be accurately performed.

In addition, counting of the number of revolutions of the rear wheels 11 is started upon the start of the first turning operation mode, and when the number of revolutions of the rear wheels 11 reaches a predetermined count value, the automatic turning operation mode is shifted to the second turning operation mode. The control using the location information may be part of the inside, so that automatic turning can be performed with simple control.

In addition, when the second second turning operation mode toward the turning end position P2 is ended, the automatic straight forward mode is shifted to the automatic straight forward mode as it is, and the automatic straight forwarding is started, so that the work can be continued and workability can be improved.

Also in the third embodiment, as a modified example, for example, after the first turning operation mode is executed, the second turning operation mode is executed, the first turning operation mode is again executed, and the turning end position (P2) You may reach

Further, the first turning operation mode and the second turning operation mode may be set as an automatic turning mode in which each is executed two or more times.

In addition, in the first to third embodiments, it is preferable that the controller 100 limits the vehicle speed by setting an upper limit value to the running speed of the seedling transplanter 1 in the automatic turning mode. As a result, the turning operation is stabilized and safety can be ensured. Further, when the controller 100 determines that the turning is finished based on the positional information from the position acquisition device 150, the limit of the vehicle speed is released to set the vehicle speed according to the position of the shift operation lever (HST lever) 36.

In addition, in the first to third embodiments, the controller 100 sets the rotation speed of the rear wheel 11 to be changeable. In addition, the controller 100 releases each mode when the assist lever is "raised" by the operator while the automatic straight forward mode or the automatic turning mode is being executed.

In addition, in the first to third embodiments, the controller 100 cancels the automatic turning mode when the operator operates to turn the Z turn "off" while the automatic turning mode is being executed. In addition, the controller 100 cancels the automatic turning mode when the automatic turning switch 49 (refer to Fig. 3) is operated "off" by the operator while the automatic turning mode is being executed.

In addition, in the first to third embodiments, in the case where the controller 100 is operated to the "reverse" side, the HST lever (shift operation lever) 36 (see Fig. 3) is operated by the operator while the automatic turning mode is being executed. Turn off auto turn mode. Further, the controller 100 cancels the automatic turning mode when the steering wheel 35 (see Fig. 3) is operated by the operator while the automatic turning mode is being executed.

In addition, in the first to third embodiments, the controller 100 temporarily suspends the automatic turning mode when the seedling transplanter 1 is stopped or the engine 30 (see Fig. 1) is stopped while the automatic turning mode is being executed. Stop (hold). Further, the controller 100 may control to stop the automatic turning mode when the seedling transplanter 1 is stopped or the engine 30 is stopped while the automatic turning mode is being executed.

In addition, in the first to third embodiments, when the headland alarm release switch is pressed, the controller 100 releases the headland stop when the headland alarm is activated. Further, the controller 100 may display on the monitor 86 (see Fig. 3) whether or not automatic turning is possible. Further, the controller 100 may display an alert on the monitor 86, for example, when automatic turning is not possible.

Further, in the third embodiment, the controller 100 does not stop the automatic turning mode even if the seedling transplanter 1 stops while moving backward. In this way, even if the vehicle stops at the time of reversing due to an abnormal change such as a seedling joint, the automatic turning can be continued.

Further, in the first to third embodiments, the automatic turning mode (in the third embodiment, the operation excluding the reverse operation of the automatic turning mode) may be configured to be completed only in the first turning operation mode, and only in the second turning operation mode. You may configure it to complete.

Further, in the first to third embodiments, the start of the automatic turning may be a timing at which the "raising operation" of the lifting operation for lifting the seedling unit 4 is performed. In other words, the automatic turning switch 48 may be a switch that raises the seedling planting portion 4 by the operation of the operator, and detects the rise of the seedling planting portion 4 or controls the seedling planting portion 4 to rise. It may be a detection unit that detects initiation.

In addition, the start of the automatic turning is a timing at which power transmission to the seedling planting device 55 becomes "off", a timing at which the feeding device 71 of the fertilizing device 5 stops, or to the stopped rotor 63. The timing at which the power transmission is "off" may be sufficient.

In this way, the timing of starting the automatic turning may be a timing at which the driving of the packaging work device such as the seedling unit 4 is turned "off".

Further, the work vehicle 1 may be a tractor. In this case, the packaging operation device is a rotary or the like. Also in the turning of the tractor, the turning control can be applied.

Additional effects or modifications can be easily derived by those skilled in the art. For this reason, the broader aspects of the present invention are not limited to the specific details and representative embodiments shown and described above. Accordingly, various changes can be made without departing from the spirit or scope of the concept of the general invention defined by the scope of the appended claims and their equivalents.

1: seedling transplanter (work vehicle)
2: running body
10: front wheel (driving wheel)
35: handle (steering device)
90: rotation speed sensor (detector)
95: steering motor (motor)
100: controller (control unit)
150: position acquisition device
L1: straight driving route
L2: turning travel path
P2: Turn end position

Claims (4)

The driving wheels 10 and 11 attached to the driving vehicle body 2, a steering device 35 for adjusting the steering amount of the driving wheel 10, a motor 95 for driving the steering device 35, and , A position acquisition device 150 for receiving positioning information from the positioning means and acquiring current position information of the aircraft based on the received positioning information, and a control device 100 for controlling the motor 95, , The control device 100 controls and executes the motor 95 so that the steering amount becomes a predetermined value, regardless of the position information, while the aircraft is turning, based on the position information. And a second turning operation mode in which the motor (95) is controlled and executed so that the aircraft reaches a desired orientation on the turning travel path (L2). The method of claim 1,
The control device 100 executes the second turning operation mode when the aircraft starts turning, and when the second turning operation mode ends, executes the first turning operation mode, and the first turning operation mode ends. When the operation vehicle, characterized in that to execute the second turning operation mode. The method according to claim 1 or 2,
A detection device 90 for detecting the rotation speed of the traveling wheel 11 is further provided, and the detection device 90 starts detection of the rotation speed at the start of the first turning operation mode, and the control The device (100) is a work vehicle, characterized in that the transition to the second turning operation mode when the number of revolutions reaches a predetermined value. The method according to any one of claims 1 to 3,
The control device 100 has an automatic straight forward mode for driving the aircraft along the straight travel path L1, and when the second turning operation mode toward the desired turning end position P2 ends, the automatic straight forward mode is transferred. Work vehicle, characterized in that.

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