JP2023181796A - work vehicle - Google Patents

Abstract

To provide a work vehicle appropriately performing turning travel by detecting that inappropriate turning travel has been made.SOLUTION: A work vehicle includes an automatic work travel control part for controlling work travel by automatic travel along a straight path IPL based on a position PP of a machine body 1, and an automatic turning travel control part for controlling turning travel performed according to a predetermined prescribed procedure. When controlling the turning travel, the automatic turning travel control part calculates as a target turning circle RRC, a circle that passes through a turning start position PSR and comes into contact with the straight path IPL having traveled just before and a straight path IPL1 traveling next, calculates as a turning distance DR, a distance between a center point CRC of a target turning circle RRC and a position PP of the machine body 1 traveling, and when a difference between a radius RC of the target turning circle RRC and the turning distance DR is larger than a predetermined prescribed threshold, executes a prescribed escape control function.SELECTED DRAWING: Figure 8

Description

TECHNICAL FIELD The present invention relates to a work vehicle that performs a plurality of straight work runs with turning runs in between.

As disclosed in Patent Document 1, a rice transplanter performs work travel in a field by reciprocating along a straight path with turning travel in between. In turning travel, a turning path is not generated, and the end of work on a straight path is determined, and automatic turning is performed at a predetermined turning angle.

JP2007-244288A

However, in such a rice transplanter, turning is not performed along a turning route, but automatic turning travel is controlled according to a predetermined turning procedure. The turning procedure is controlled to turn at a predetermined turning angle. Therefore, if the aircraft skids due to field conditions or the like, the planned turn may not be carried out properly, and the aircraft may pass through an inappropriate position and end the turn at an inappropriate position.

An object of the present invention is to detect that an inappropriate turning has been performed and to appropriately perform the turning.

In order to achieve the above object, a work vehicle according to an embodiment of the present invention is a work vehicle that travels for work in a field by repeating turning travel and straight travel, and has a body and a position of the body. an aircraft position calculation unit that calculates the aircraft position; a route generation unit that generates a straight path for performing the straight forward travel; and an automatic work drive that controls the work travel by automatic travel along the straight route based on the position of the aircraft. and an automatic turning driving control unit that controls the turning driving performed in a predetermined procedure, and the automatic turning driving control unit controls the turning start position when controlling the turning driving. The circle tangent to the straight line route traveled immediately before and the straight line route traveled next is calculated as a target turning circle, and the distance between the center point of the target turning circle and the position of the aircraft during travel is calculated as the turning distance. If the difference between the radius of the target turning circle and the turning distance is greater than a predetermined threshold, a predetermined escape control function is executed.

Automatic turning is performed according to a predetermined procedure, and this procedure is set so that turning is appropriately performed from one straight route to the next straight route. At this time, the aircraft may slip during automatic turning and the appropriate turning may not be performed, and even if automatic turning is performed according to the prescribed procedure, it may not be possible to reach the appropriate position on the next straight path. be. Furthermore, since a travel route is not generated during automatic turning, while the automatic turning can be easily controlled, it is not possible to confirm whether or not the turning is appropriate during automatic turning.

According to the above configuration, during automatic turning, the target turning circle is virtually calculated, and the turning distance is compared with the radius of the target turning circle, even though the aircraft is not controlled to follow the target turning circle. If the turning distance deviates from the radius of the target turning circle by more than a threshold value, it can be determined that the aircraft has escaped due to slipping or the like and is not performing an appropriate automatic turning. If it is determined that appropriate automatic turning is not being performed, an escape control function is executed, and measures can be taken to ensure that appropriate automatic turning is performed. As a result, it is detected that inappropriate turning is being performed, and automatic turning can be performed appropriately.

Further, the escape control function may be a control that decelerates the aircraft at least once or more.

With this configuration, when it is determined that appropriate automatic turning is not being performed, measures can be taken to ensure appropriate turning while the aircraft is being decelerated.

Moreover, the escape control function may be a control that stops a working part of the aircraft body.

With such a configuration, when it is determined that appropriate automatic turning is not being performed, it is possible to easily take measures to ensure appropriate turning.

Moreover, the escape control function may be a control for stopping the aircraft.

With such a configuration, if it is determined that appropriate automatic turning is not being performed, the aircraft is temporarily stopped, and then it is possible to easily take measures such that appropriate turning is performed.

Additionally, if the aircraft makes a turn with a large bulge, the aircraft may come into contact with the ridge. By stopping the aircraft when it is determined that appropriate automatic turning is not being performed, it is possible to appropriately prevent the aircraft from coming into contact with the ridge.

Further, the difference between the radius of the target turning circle and the turning distance is calculated as an absolute value, and the automatic turning travel control section calculates that the absolute value of the difference between the radius of the target turning circle and the turning distance is less than the threshold value. Even if the turning distance is larger than the radius of the target turning circle, the escape control function may be disabled if the turning distance is smaller than the radius of the target turning circle.

A situation where the turning distance becomes smaller than the radius of the target turning circle is a situation where the aircraft is turning too much at a large turning angle (small turning radius) and the aircraft deviates inward from the expected turning trajectory when turning according to the procedure. be. In such a situation, even if the vehicle is not heading to an appropriate position on the next straight route, there is a small possibility that the vehicle will come into contact with a ridge. Furthermore, by performing appropriate steering control at the final stage of turning or at the initial stage of traveling on a straight route, there is a possibility that the vehicle can travel along a straight route.

Therefore, according to the above configuration, even if it is determined that an appropriate automatic turning operation is not being performed, if the aircraft is shifted inward, the escape control function is not performed, thereby efficiently allowing automatic turning operation and subsequent can continue to work.

In addition, when controlling the turning, the automatic turning travel control unit turns the aircraft at a predetermined steering angle, and the automatic turning travel control unit rotates the aircraft at a predetermined steering angle, and the automatic turning travel control unit rotates the aircraft at a predetermined steering angle, and the automatic turning travel control unit rotates the aircraft at a predetermined steering angle. The turning movement may be terminated when the angle with the straight path becomes less than or equal to a predetermined angle.

During turning, when the direction of movement of the aircraft approaches the same direction as the direction of travel of the next straight path, it can be determined that the end position of the turn has been approached, and the direction of movement of the aircraft is approximately the same as the direction of travel of the straight path. If they match, automatic work travel along a straight path can be started from there.

According to the above configuration, it is possible to easily perform automatic turning travel and then smoothly shift to automatic work travel along a straight path.

It is a left side view illustrating the whole structure of a rice transplanter. FIG. 1 is a plan view illustrating the overall configuration of a rice transplanter. FIG. 3 is a diagram illustrating the configuration of main parts of an operation panel. It is a figure explaining work traveling. FIG. 3 is a diagram illustrating an example of generating a straight route. It is a figure explaining the example of the procedure of turning travel. FIG. 2 is a diagram illustrating a functional configuration for controlling automatic driving. It is a figure explaining the example of control in automatic turning travel. It is a figure explaining the example of the flow of automatic turning travel.

Hereinafter, a rice transplanter that travels in a field will be described as an example of a working vehicle.

Here, for ease of understanding, in this embodiment, unless otherwise specified, "front" (direction of arrow F shown in FIGS. 1 and 2) means the front in the longitudinal direction (traveling direction) of the aircraft. However, "rear" (the direction of arrow B shown in FIGS. 1 and 2) means the rear in the longitudinal direction (traveling direction) of the aircraft. In addition, the left-right direction or lateral direction means the transverse direction of the fuselage (aircraft width direction) orthogonal to the longitudinal direction of the fuselage, and "left" (direction of arrow L shown in Figure 2) and "right" (arrow shown in Figure 2) R direction) shall mean the left direction and the right direction of the aircraft, respectively.

[Overall structure]
As shown in FIGS. 1 and 2, the rice transplanter includes a body 1 of a riding type and a four-wheel drive type. The fuselage 1 includes a link mechanism 13 in the form of parallel quadruple links connected to the rear of the fuselage 1 so as to be able to swing up and down, a hydraulic lift link 13a that swings the link mechanism 13, and a rear end area of the link mechanism 13. The seedling planting device 3 is rollably connected to the seedling planting device 3. The seedling planting device 3 is an example of a working device, and a fertilizing device, a chemical spraying device, etc. may be installed as other working devices.

The aircraft body 1 includes wheels 12 as a mechanism for traveling, an engine 2, and a hydraulic continuously variable transmission 9 as a main transmission. The continuously variable transmission 9 is, for example, an HST (Hydro-Static Transmission), and changes the speed of the driving force output from the engine 2 by adjusting the angles of a motor swash plate and a pump swash plate. The wheels 12 include steerable left and right front wheels 12A and non-steerable left and right rear wheels 12B. The engine 2 and the continuously variable transmission 9 are mounted on the front part of the aircraft body 1. The power output from the engine 2 is supplied to the front wheels 12A, rear wheels 12B, working equipment, etc. via the continuously variable transmission 9 and the like.

The seedling planting device 3 is configured, for example, in an 8-row planting format. The seedling planting device 3 includes a seedling mounting table 21, a planting mechanism 22 for eight rows, five floats 15, and the like. Note that this seedling planting device 3 can be changed to a format such as 2-row planting, 4-row planting, 6-row planting, etc. by controlling each row clutch (planting clutch 23).

The seedling mounting stand 21 is a pedestal on which eight rows of mat-like seedlings are placed. The seedling platform 21 reciprocates in the left and right direction with a constant stroke corresponding to the left and right width of the mat-shaped seedlings, and each time the seedling platform 21 reaches the left and right stroke ends, each mat-shaped seedling on the seedling platform 21 is moved back and forth. The seedlings are vertically fed toward the lower end of the seedling platform 21 at a predetermined pitch.

The eight planting mechanisms 22 are of a rotary type and are arranged in the left-right direction at regular intervals corresponding to the planting rows. Then, each planting mechanism 22 receives driving force from the engine 2 by shifting the planting clutch 23 to a transmission state, and the planting mechanism 22 receives one plant from the lower end of each mat-shaped seedling placed on the seedling platform 21. Cut out the seedlings and plant them in the muddy soil area after leveling the land. Thereby, the seedling planting device 3 can take out the seedlings from the mat-shaped seedlings placed on the seedling platform 21 and plant them in the muddy soil part of the paddy field.

The float 15 levels the field during seedling planting work. Each float 15 is provided in association with a planting mechanism 22 for two rows.

The fuselage 1 includes a driving section 14 in its rear region. The driving unit 14 includes a steering wheel 10 for steering the front wheels, a main shift lever 7 that adjusts the vehicle speed by changing the speed of the continuously variable transmission 9, a lifting operation of the seedling planting device 3, and an on/off operation of the planting clutch 23. It includes a work operation lever 11 for operating (switching between a transmission state and a non-transmission state), a driver's seat 16 for an operator (driver/worker), and the like. The steering wheel 10, the main shift lever 7, and the work operation lever 11 are provided on the driving panel 6 in front of the driver's seat 16. Further, in front of the driving unit 14, a spare seedling storage device 17A for storing spare seedlings is supported by the spare seedling support frame 17.

Further, the preliminary seedling support frame 17 is provided with a positioning unit 8. The positioning unit 8 outputs positioning data for calculating the position PP (see FIG. 5) and direction of the aircraft 1. The positioning unit 8 includes a satellite positioning module 8A that receives radio waves from a Global Navigation Satellite System (GNSS) satellite, and an inertial measurement module 8B that detects the tilt and acceleration of the aircraft 1 in three axes.

Further, as shown in FIG. 3, the operation panel 6 is provided with a start position operating tool 18 and an end position operating tool 19. The start position operating tool 18 and the end position operating tool 19 are arranged below the steering wheel 10 of the driving panel 6 and are divided into right and left parts. The starting position operating tool 18 is operated when determining a starting point PA (see FIG. 5) in a teaching run, which will be described later. The end position operating tool 19 is operated when determining the end point PB (see FIG. 5) in the teaching run. The start position operating tool 18 and the end position operating tool 19 may be any operating tool that allows input operations, such as push buttons. Further, the arrangement of the start position operating tool 18 and the end position operating tool 19 is not limited to the arrangement shown in FIG. 3, but may be arranged at positions where the driver can operate them while the vehicle is running.

[Work driving]
The working movement of a rice transplanter in rice planting work in a field will be explained using FIG. 4 while referring to FIGS. 1 and 2.

The rice transplanter in this embodiment can selectively run manually or automatically. In manual travel, the driver manually operates work travel operating tools such as the steering wheel 10, the main shift lever 7, and the work operation lever 11 to perform work travel. In automatic travel, the rice transplanter travels and performs work under automatic control, and performs straight work travel along a straight route IPL, which will be described later, with turning travel in between. At this time, the turning movement is automatically controlled according to a predetermined procedure without generating a driving route.

When the rice transplanter performs planting work, the field is divided into an outer peripheral area OA and an inner area IA, and work travel is performed according to each area.

In the internal region IA, a plurality of linear paths IPL (internal reciprocating paths) substantially parallel to one side of the field are generated. The straight route IPL is a travel route that travels all over the interior area IA, and each straight route IPL travels with turning travel in between. Each time the vehicle makes a turn, the next straight route IPL is generated in sequence.

After work travel is performed in the inner area IA, work travel is performed in the outer peripheral area OA. Work travel in the outer peripheral area OA is performed by automatic travel or manual travel. When automatic work travel is performed in the outer peripheral area OA, two driving routes are generated, an inner circular route IRL and an outer circular route ORL, which travel around the outer peripheral area OA along the outer periphery of the field. By traveling along the inner circumferential route IRL and the outer circumferential route ORL, the entire outer circumferential area OA is operated. Note that the running route that goes around the outer circumferential area OA is not limited to two, the inner loop route IRL and the outer loop route ORL, but may be one or more running routes.

[Automatic work travel along a straight path]
Next, while referring to FIGS. 1 to 4, automatic work travel on a straight path will be explained using FIG. 5.

First, teaching travel is performed in which manual travel is performed from one end of the internal area IA to the other end. In the teaching travel, the driver operates the start position operating tool 18 at the position where the work travel is to be started, and registers the starting point PA of the teaching travel. Then, the driver manually performs linear work travel (manual travel), and when reaching the end position of the work travel, operates the end position operating tool 19 to register the end point PB of the teaching travel. Note that the end point PB may be a position traveled straight from the end position of the working travel while the seedling planting device 3 is being raised.

The straight line connecting the starting point PA and the ending point PB is the basic straight line RL, and at least one of the basic straight line RL and the reference direction RD, which is a direction parallel to the basic straight line RL, is registered.

Next, in order to perform a reciprocating work run, the driver performs a predetermined operation to turn the aircraft 1 180 degrees by automatic turning to be described later.

The end position PE (see Figure 6) of automatic turning travel becomes the start position PSS of straight-ahead travel, and a straight line passing through the start position PSS and parallel to the basic straight line RL (in the direction of the reference direction RD) is the straight line route IPL to be traveled next. is generated as . Note that the straight route IPL may be defined by the starting position PSS of straight traveling and the traveling direction (direction parallel to the reference direction RD), but it is also a set of the starting position PSS and the position PP of the aircraft 1 to be traveled thereafter. , or may be defined as a line segment connecting the straight-ahead travel start position PSS and the straight-ahead travel end position.

Then, the driver starts automatic work travel along the straight route IPL. Thereafter, automatic work travel and automatic turning travel along the straight route IPL are repeated, and each time the automatic turning travel is completed, the next straight route IPL is generated and reciprocating travel over the entire interior area IA is performed.

[Automatic turning travel]
Next, automatic turning traveling will be explained using FIG. 6 while referring to FIGS. 1 and 5.

Automatic turning travel is started by performing a predetermined manual operation. The automatic turning travel is performed in the outer peripheral area OA, but particularly in the area inside the field by a predetermined distance from the ridge RW. Automatic turning travel is not performed along a travel route, but is performed according to a predetermined procedure determined by controlling the traveling devices such as the wheels 12 according to a predetermined procedure.

For example, in automatic turning driving, when work driving on the straight path IPL is completed and a predetermined manual operation is performed at the start position PSR, the front wheels 12A are first set at a predetermined steering angle, for example, the maximum steering angle. Turning is performed by operating the vehicle. The traveling trajectory in this traveling becomes C1 shown in FIG.

Next, when the turning angle α reaches a predetermined turning angle αC1, the steering angle is reduced. For example, when the turning angle α becomes 90° as the turning angle αC1, the steering angle is set to 0°. That is, when the turning angle α becomes 90°, the aircraft 1 travels in a direction perpendicular to the straight path IPL, in other words, in a direction parallel to the ridge boundary line RBL. Here, the turning angle α is the angle formed by the straight line connecting the position PP of the moving aircraft 1 and the midpoint CC and the ridge boundary line RBL. The midpoint CC is the midpoint between the turning start position PSR of the straight route IPL on which the work run was performed immediately before and the start position PSS of the work run (the end position PE of the turn) on the straight route IPL to be traveled next. . Furthermore, the ridge boundary line RBL is a straight line connecting the start position PSR and the end position PE, and is a straight line that passes through the start position PSR and is perpendicular to the straight line route IPL or the basic straight line RL. Note that the traveling trajectory in this traveling becomes C2 shown in FIG. 6.

Then, when the turning angle α reaches a predetermined turning angle αC2 (the remaining turning angle is αC3 = 180° - αC2), the steering angle is operated to a predetermined predetermined angle, and the turning end position PE (straight path IPL) is reached. A turning run is carried out towards. At this time, automatic steering may be performed toward the end position PE of the turn. The traveling trajectory in this traveling becomes C3 shown in FIG.

[Automatic driving control]
Next, a functional configuration for controlling automatic travel that performs automatic straight-ahead travel (automatic work travel) and automatic turning travel will be described using FIG. 7 with reference to FIGS. 1 and 5.

Automatic driving is controlled by a control unit 30. The positioning unit 8, travel switching operating tool 25, starting position operating tool 18, ending position operating tool 19, and wheels 12 are connected to the control unit 30 in a state where data communication is possible.

Control unit 30 receives positioning data from positioning unit 8 . Further, the control unit 30 receives information on whether the travel switching operation tool 25, the start position operation tool 18, and the end position operation tool 19 have been operated. Note that the travel switching operation tool 25 accepts a manual operation for switching between automatic travel and manual travel. Further, the control unit 30 controls the wheels 12 to control traveling and steering of the aircraft body 1 .

The control unit 30 includes a body position calculation section 32 , a route generation section 33 , an automatic work travel control section 35 , and an automatic turning travel control section 36 .

The aircraft position calculation unit 32 intermittently or continuously calculates the position PP of the aircraft 1 in the field based on the positioning data received from the positioning unit 8.

The route generation unit 33 calculates at least one of the basic straight line RL and the reference direction RD in the above-described teaching travel. Then, the route generating unit 33 generates a straight line route IPL to be traveled next each time the vehicle turns, using the calculated basic straight line RL or reference direction RD.

Note that the rice transplanter may include a notification section 26 that makes a predetermined notification. In this case, the notification section 26 is connected to the control unit 30, and performs predetermined notification under the control of the control unit 30. Then, the route generating section 33 causes the notifying section 26 to make a predetermined notification when the starting point PA and the ending point PB are registered in the teaching run. For example, the notification unit 26 is a speaker, and the route generation unit 33 causes the speaker to generate a predetermined notification sound when the starting point PA and the ending point PB are registered.

Further, along with or instead of the notification sound, the route generation unit 33 may cause the LED, which is the notification unit 26, to emit light to notify that the start point PA and the end point PB have been registered. Furthermore, the start position operating tool 18 and the end position operating tool 19 may be push buttons, and an LED may be provided on the surface of each push button as the notification section 26. Then, the route generation unit 33 may turn on the LED of the start position operating tool 18 when the starting point PA is registered, and may turn on the LED of the end position operating tool 19 when the end point PB is registered.

The automatic work travel control unit 35 controls automatic work travel along the straight path IPL based on the position PP of the machine body 1 while controlling work devices such as the seedling planting device 3 .

The automatic turning travel control unit 36 causes the aircraft 1 to turn according to a predetermined procedure when a predetermined manual operation is performed. Further, the automatic turning travel control unit 36 performs processing for executing an escape control function, which will be described later, during automatic turning travel.

Furthermore, when the automatic turning mode is entered, the automatic turning travel control section 36 may perform control to stop the planting clutch 23 (see FIG. 2) and raise the seedling planting device 3.

[Control during automatic turning]
Next, with reference to FIG. 7 and FIGS. 8 and 9, control executed during automatic turning will be described.

When automatic turning driving is started (step #1 in FIG. 9), automatic turning driving control section 36 calculates a target turning circle RRC (step #2 in FIG. 9). The target turning circle RRC is a circle that passes through the starting position PSR (turning start position) of automatic turning driving and is in contact with the straight line route IPL on which work driving was performed immediately before automatic turning driving and the straight line route IPL1 to be traveled next. . However, the automatic turning travel control unit 36 does not control the aircraft 1 to travel along the target turning circle RRC during automatic turning travel.

Next, the automatic turning travel control unit 36 calculates the center point CRC of the target turning circle RRC (step #3 in FIG. 9). For example, the automatic turning travel control unit 36 draws a perpendicular line from the starting position PSR to the straight line route IPL1, and calculates the midpoint between the intersection of this perpendicular line and the straight line route IPL1 and the starting position PSR as the center point CRC.

Next, the automatic turning travel control unit 36 calculates the radius RC of the target turning circle RRC (step #4 in FIG. 9). For example, the automatic turning travel control unit 36 calculates the distance from the intersection of the above-mentioned perpendicular line and the straight path IPL1 to the start position PSR as the diameter of the target turning circle RRC, and calculates the radius RC of the target turning circle RRC from the diameter. .

The automatic turning travel control unit 36 continuously calculates the turning distance DR during automatic turning travel (step #5 in FIG. 9). The turning distance DR is the distance between the position PP of the aircraft 1 during automatic turning and the center point CRC of the target turning circle RRC.

From the start to the end of automatic turning travel, the automatic turning travel control unit 36 continuously calculates the difference between the turning distance DR and the radius RC. Then, the automatic turning travel control unit 36 determines whether the absolute value of the difference between the calculated turning distance DR and radius RC is larger than a predetermined threshold (step #6 in FIG. 9). . In other words, the automatic turning travel control unit 36 approximately calculates the amount of deviation with respect to the cornering travel that is assumed when the turning travel is performed in a predetermined procedure based on the difference between the turning distance DR and the radius RC, and Determine whether or not this is being done appropriately. As long as the absolute value of the difference between the turning distance DR and the radius RC is less than or equal to the threshold value (No in step #6 in FIG. 9), the automatic turning driving control section 36 continues to control the automatic turning driving.

When the absolute value of the difference between the turning distance DR and the radius RC becomes larger than the threshold value (Step #6 Yes in FIG. 9), the automatic turning driving control unit 36 determines that the automatic turning driving is not performed appropriately, and the aircraft The escape control function for stopping the vehicle 1 is executed (step #7 in FIG. 9).

As a result, the target turning circle RRC is virtually regarded as the trajectory of automatic turning, and it is determined from the amount of deviation between the target turning circle RRC and the aircraft 1 whether or not automatic turning is being performed appropriately. can be easily determined. Then, when it is determined that the automatic turning operation is not being performed properly, the aircraft 1 is stopped, and then the aircraft 1 is turned manually or the steering angle during automatic turning operation is adjusted. , it is possible to continue to make appropriate turns.

In addition, when the notification unit 26 is provided, the automatic turning travel control unit 36 may cause the notification unit 26 to issue a predetermined notification when executing the escape control function.

[Another embodiment]
(1) In the above embodiment, the aircraft 1 is stopped as an escape control function, but the escape control function is not limited to such control. For example, the automatic turning travel control section 36 may stop at least one of the engine 2, the planting mechanism 22 (corresponding to a working section), and the seedling planting device 3 as an escape control function. Thereby, it is possible to easily take measures when restarting turning travel.

Further, the automatic turning travel control unit 36 may decelerate the aircraft 1 (decelerate the vehicle speed) at least once as an escape control function. This also makes it possible to take necessary measures such as changing the turning angle while the vehicle speed is being reduced, and then perform appropriate turning.

Also, deceleration may be performed in stages while checking the turning situation. For example, if the amount of deviation is still large after the first deceleration, the deceleration may be performed multiple times, such as performing a second deceleration with an even larger deceleration width. Turning may be adjusted by decelerating over a period of time.

(2) In each of the above embodiments, even if the absolute value of the difference between the turning distance DR and the radius RC is greater than the threshold value, if the turning distance DR is smaller than the radius RC, the escape control function of the automatic turning travel control unit 36 is disabled. You can also use it as

If the turning distance DR is smaller than the radius RC, the turning movement of the aircraft 1 is not deviated in the direction of expanding toward the ridge RW, but the aircraft 1 is turning toward the center point CRC at a small turning angle α. This is the situation. In such a situation, the possibility that the aircraft 1 will come into contact with the ridge RW is small. Therefore, when the turning distance DR is smaller than the radius RC, even if the escape control function of the automatic turning control section 36 is disabled, there is a relatively small possibility that a problem will occur in the turning. By performing such control, continuity of turning travel is maintained.

(3) In each of the embodiments described above, automatic turning travel is not limited to the above-described procedure described using FIG. 6, but may be performed according to any predetermined procedure. For example, the automatic turning travel control unit 36 may fix the steering angle and cause the automatic turning travel to be performed at one predetermined steering angle. In this case as well, the automatic turning travel control unit 36 performs automatic steering at the final stage of the turning travel based on the automatic work travel start position PSS of the next straight route IPL and the position PP of the aircraft 1. good.

In addition, the automatic turning operation is not limited to a configuration in which the automatic turning operation is performed up to the starting position PSS of the straight line route IPL to be traveled next, but the automatic turning operation is performed when the traveling direction of the aircraft 1 is a predetermined direction of travel of the straight route IPL to be traveled next. It may be terminated when the distance approaches by a certain amount. For example, the automatic turning travel control unit 36 may end the automatic turning travel when the angle between a straight line parallel to the traveling direction of the aircraft 1 and the next straight line route IPL becomes less than or equal to a predetermined angle.

Note that after the automatic turning travel is completed, the automatic work travel control section 35 performs steering control of the aircraft 1 so as to follow the next straight route IPL.

(4) In each of the above embodiments, if there is an obstacle in front of the vehicle in the direction of travel or around the aircraft 1 at the start of automatic travel or during automatic travel, problems may occur in travel or work. Therefore, the rice transplanter of this embodiment may include a sonar sensor as an example of the obstacle detection device 28 (see FIG. 7) that detects obstacles around the machine body 1. The sonar sensor detects objects within a predetermined distance as obstacles. Obstacle detection is basically performed during automatic driving, but it may also be configured such that obstacle detection is performed during manual driving.

The travel prohibition control unit 38 stops the aircraft 1 when the sonar sensor detects an obstacle. Thereby, it is possible to suppress the aircraft 1 from coming into contact with obstacles. Note that such control may be performed not only during automatic work travel along the straight route IPL, but also during automatic turning travel, and may also be performed during manual travel.

(5) In each of the above embodiments, the rice transplanter may be driven not only by the engine 2 but also by any other prime mover.

(6) In each of the above embodiments, the traveling device is not limited to the wheels 12, but may be any traveling device such as a crawler.

(7) In each of the embodiments described above, the control unit 30 is not limited to being composed of functional blocks as described above, but may be composed of arbitrary functional blocks. For example, each functional block of the control unit 30 may be further subdivided, or conversely, a part or all of each functional block may be combined. Further, the functions of the control unit 30 are not limited to the above-mentioned functional blocks, and may be realized by a method executed by any functional block. Moreover, some or all of the functions of the control unit 30 may be configured by software. The software program is stored in any storage device and executed by a processor such as a CPU included in the control unit 30 or a separately provided processor.

Further, the rice transplanter may include an information terminal 5. The information terminal 5 has a touch panel (monitor screen) that displays various information and warnings and notifies (outputs) them to the operator, as well as accepts input of various information. Further, the information terminal 5 is removably installed in the driver's unit 14 in a manner that allows the driver seated on the driver's seat 16 to view and operate the information terminal 5 . The control unit 30 may be configured to be mounted on the aircraft body 1, but some or all of the functions of the control unit 30 may be provided in the information terminal 5.

The present invention can be applied to rice transplanters, agricultural vehicles that work in fields while making turns, and various types of work vehicles that work in fields while making turns.

1 Aircraft 22 Planting mechanism (working part)
32 Aircraft position calculation unit 33 Route generation unit 35 Automatic work travel control unit 36 Automatic turning travel control unit CRC Center point DR Turning distance DRP Ridge distance IPL Straight path IPL1 Straight path PP Position PSR Start position (turning start position)
RC Radius RRC Target turning circle

Claims (6)

A work vehicle that performs work driving in a field by repeating turning driving and straight driving,
The aircraft and
an aircraft position calculation unit that calculates the position of the aircraft;
a route generation unit that generates a straight route for the straight-ahead traveling;
an automatic work travel control unit that controls the work travel by automatic travel along the straight path based on the position of the aircraft;
an automatic turning driving control unit that controls the turning driving performed according to a predetermined procedure,
When controlling the turning, the automatic turning travel control unit calculates, as a target turning circle, a circle that passes through the turning start position and is in contact with the straight line route traveled immediately before and the straight line route traveled next; The distance between the center point of the target turning circle and the position of the traveling aircraft is calculated as a turning distance, and if the difference between the radius of the target turning circle and the turning distance is larger than a predetermined threshold value, , a work vehicle that performs predetermined escape control functions. The work vehicle according to claim 1, wherein the escape control function is a control that decelerates the aircraft at least once or more. The work vehicle according to claim 1 or 2, wherein the escape control function is a control for stopping a working section of the machine body. The work vehicle according to claim 1 or 2, wherein the escape control function is a control for stopping the aircraft. The difference between the radius of the target turning circle and the turning distance is calculated as an absolute value,
Even if the absolute value of the difference between the radius of the target turning circle and the turning distance is greater than the threshold value, the automatic turning travel control unit may be configured to The work vehicle according to claim 1 or 2, wherein the escape control function is disabled. When controlling the turning, the automatic turning travel control unit turns the aircraft at a predetermined steering angle, and the automatic turning travel control unit rotates the aircraft at a predetermined steering angle, and selects a straight line parallel to the traveling direction of the aircraft and the straight line route to be traveled next. The work vehicle according to claim 1 or 2, wherein the turning travel is terminated when the angle formed by the vehicle becomes equal to or less than a predetermined angle.

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