JP2023181797A - work vehicle - Google Patents

Abstract

To provide a work vehicle capable of accurately controlling travel or work, according to a state of a work place, a model, and a travel state.SOLUTION: A work vehicle comprises: a machine body; a travel unit 12 provided on the machine body; a machine body position calculating part 32 for calculating a position of the machine body and a travel azimuth of the machine body; an information acquiring part 24 for acquiring prescribed turning time information 40 in turning travel; and an automatic turning travel control part 36 for controlling a steering angle of the travel unit 12 in the turning travel in a predetermined prescribed procedure. The automatic turning travel control part 36 performs control for returning a steering angle to an original angle so that the machine body travels straightly, when an angle difference between a target azimuth of a straight path where the work vehicle travels after the turning travel, and the travel azimuth becomes a prescribed threshold 45 or lower, during the turning travel, and the automatic turning travel control part 36 changes the threshold according to the turning time information 40.SELECTED DRAWING: Figure 5

Description

The present invention relates to a work vehicle in which control parameters (setting values) are set and running is controlled using the control parameters (setting values).

For example, Patent Document 1 states that in automatic turning control, the difference between the direction of the vehicle body and the direction in which the vehicle is to go straight (the direction of travel on the next route) falls below a predetermined steering angle return level (threshold value). and the steering angle is controlled to return to normal.

JP 2021-185064 Publication

However, the control parameters (setting values) depend on the model, driving conditions, work site conditions, etc., and it is not always possible to optimally control driving with constant control parameters (setting values). For example, if the steering angle of the steering wheel is returned to the straight-ahead state during a turn, the distance the aircraft will travel until the steering wheel returns to the straight-ahead angle or the traveling device returns to the straight-ahead state will vary depending on the vehicle speed. . Therefore, if the steering angle return level (threshold value) is controlled to be constant, depending on the traveling vehicle speed, it may not be possible to appropriately transition from turning to straight-ahead driving.

An object of the present invention is to accurately control traveling or work according to the model, traveling conditions, work site conditions, etc.

In order to achieve the above object, a working vehicle according to an embodiment of the present invention performs work traveling in a field by performing reciprocating travel in which the vehicle travels along a plurality of straight paths parallel to each other with turning travel in between. An aircraft body, a traveling device provided on the aircraft body, an aircraft position calculation unit that calculates a position of the aircraft body and a running direction of the aircraft body, and an information acquisition unit that acquires predetermined turning information during the turning movement. and an automatic turning driving control unit that controls the steering angle of the traveling device during the turning movement according to a predetermined procedure, and the automatic turning driving control unit controls the turning movement during the turning movement. When the angle difference between the target azimuth of the straight line route to be subsequently traveled and the traveling azimuth becomes less than or equal to a predetermined threshold value, the steering angle is controlled to be returned so that the aircraft travels straight; , the threshold value is changed according to the turning information.

Automatic turning is performed according to a predetermined procedure so as to end the turning at a predetermined position. Turning is affected by vehicle speed during turning, field conditions, aircraft conditions such as aircraft width, etc., and due to these factors, the planned turning may not be realized.

According to the above configuration, arbitrary information such as traveling vehicle speed can be acquired as turning information during automatic turning, and the threshold value for ending the turning can be changed in accordance with the turning information. As a result, automatic turning can be ended under appropriate conditions according to the turning information, and automatic turning can be controlled with high precision.

The device may further include a storage unit that stores model information of the aircraft, the information acquisition unit may include a model information acquisition unit that acquires the model information from the storage unit, and the turning information may include the model information. .

As mentioned above, the turning movement is affected by the width of the aircraft, which can be read from the model information. According to the above configuration, automatic turning can be ended under appropriate conditions depending on the width of the aircraft, etc., and automatic turning can be controlled with high precision.

Further, the automatic turning travel control section may change the traveling vehicle speed of the aircraft body to a predetermined turning vehicle speed at the start of the turning travel.

With this configuration, automatic turning can be performed at a traveling vehicle speed at which appropriate turning can be expected, and automatic turning can be performed with high precision.

Further, the information acquisition unit includes a viscosity detection unit that detects the viscosity of the field and a vehicle speed detection unit that detects the traveling vehicle speed of the aircraft, and the turning information includes viscosity information that is the viscosity information and the turning It may also include the traveling vehicle speed during traveling.

As mentioned above, turning movement is affected by the aircraft skidding due to the viscosity of the field. According to the above configuration, automatic turning can be ended under appropriate conditions depending on the viscosity of the field, and automatic turning can be controlled with high precision.

Further, the turning movement is affected by the traveling vehicle speed during the turning movement. According to the above configuration, automatic turning driving can be ended under appropriate conditions depending on the traveling vehicle speed, and automatic turning driving can be controlled with high precision.

Further, the information acquisition section includes a vehicle speed detection section that detects a traveling vehicle speed of the aircraft, and the automatic turning traveling control section has a reference vehicle speed for the turning traveling set in advance, and the turning information includes the traveling vehicle speed and the vehicle speed. It may also include a difference in reference vehicle speed.

With such a configuration, it is possible to determine the running vehicle speed, which affects cornering, based on the reference vehicle speed. Thereby, it is possible to easily determine whether it is necessary to change the threshold value, and when necessary, it is possible to terminate automatic turning driving under appropriate conditions depending on the traveling vehicle speed. As a result, automatic turning travel can be controlled with high precision.

The vehicle further includes a positioning unit that acquires radio waves from a satellite and outputs positioning data for calculating the position of the aircraft, and the automatic turning driving control section is configured to control a maximum turning vehicle speed that is an upper limit vehicle speed in the turning driving. The maximum turning vehicle speed may be set based on the positioning accuracy of the positioning unit.

Turning is also affected by the positioning accuracy of the positioning unit. According to the above configuration, the maximum turning vehicle speed during turning travel can be set according to the positioning accuracy of the positioning unit. Therefore, automatic turning travel can be controlled with high accuracy according to the positioning accuracy of the positioning unit.

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. It is a figure explaining work traveling. It is a figure explaining the example of the procedure of automatic turning travel. FIG. 2 is a diagram illustrating a functional configuration for controlling automatic driving. 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) The directions R) refer to the left direction and the right direction of the aircraft 1, 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 that is 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 (corresponding to a "traveling device") 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. 4) and direction of the aircraft 1. The positioning unit 8 includes a satellite positioning module 8A that receives radio waves from satellites of the Global Navigation Satellite System (GNSS), and an inertial measurement module 8B that detects the tilt and acceleration of the aircraft 1 in three axes. include.

[Work driving]
The working movement of a rice transplanter in rice planting work in a field will be explained using FIG. 3 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 back and forth with turning travel in between. Each time the vehicle makes a turn, the next straight route IPL is generated in sequence. Furthermore, each straight route IPL includes a target orientation RD (see FIG. 4) for automatic travel (straight travel) along the straight route IPL.

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 turning travel]
Next, automatic turning traveling will be explained using FIG. 4 while referring to FIGS. 1 and 3.

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 route IPL is completed and a predetermined manual operation is performed at the turning start position PSR, the front wheels 12A (traveling device) are first steered at a predetermined steering angle. For example, turning is performed by operating the steering angle to the maximum. During turning, the traveling direction CD of the aircraft 1 at the position PP of the aircraft 1 is continuously or continuously acquired.

During automatic turning, the target direction RD of the straight route IPL1 (next) to be traveled after the end of the turn is compared with the traveling direction CD. Next, when the angular difference θ between the target direction RD and the running direction CD becomes less than or equal to a predetermined threshold value 45 (see FIG. 5), the steering angle is returned so that the aircraft 1 travels straight (the steering angle is set to 0). ).

After that, automatic travel control is performed so that the vehicle travels along the straight route IPL1. As a result, the automatic travel control is transferred from automatic cornering to straight-ahead automatic travel.

[Automatic driving control configuration]
Next, a control configuration for automatic driving will be described using FIG. 5 while referring to FIGS. 1 and 4.

The operation and running of the rice transplanter during automatic running is controlled by a control unit 30 including a processor such as a CPU based on various control parameters (setting values). The control unit 30 communicates data with the positioning unit 8, the information acquisition unit 24, the obstacle detection device 28, the storage unit 29, the wheels 12 as a traveling device, the notification unit 26, and the information terminal 5 via a communication unit (not shown), etc. Connected with communication possible.

The positioning unit 8 transmits positioning data, and the control unit 30 calculates the position PP and traveling direction CD of the aircraft 1 based on the positioning data received from the positioning unit 8.

The information acquisition unit 24 acquires various types of information acquired during automatic turning driving as turning information 40. The turning information 40 includes vehicle speed information 40A, which is information on the traveling vehicle speed Vr of the aircraft 1 (see FIG. 6), and model information 40B regarding the model. The information acquisition section 24 includes a vehicle speed detection section 41 and a model information acquisition section 42. The vehicle speed detection unit 41 acquires the traveling vehicle speed Vr of the aircraft 1 as vehicle speed information 40A, and stores it in the storage unit 29, which will be described later. The model information acquisition unit 42 obtains model information 40B of the aircraft 1 and stores it in the storage unit 29, which will be described later. The model information 40B may be input and stored in the initial setting before the rice transplanter runs, or may be stored in the storage unit 29 in advance (at the time of shipping the machine 1, etc.).

The storage unit 29 stores various information such as turning information 40 and various control parameters (setting values). The storage unit 29 also stores, as one of the control parameters (set values), a preset threshold value 45 for returning the steering angle during automatic turning. Note that the storage section 29 may be provided in the control unit 30.

The notification unit 26 and the information terminal 5 are provided as necessary to display necessary information, issue warnings, and the like. The notification unit 26 is an LED, a voice alarm generator, a speaker, and the like. The information terminal 5 has a touch panel (monitor screen) that displays various types of information and notifies (outputs) them to the operator, as well as accepts input of various types of information.

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 and traveling direction CD 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 a basic straight line and a reference direction for generating the straight route IPL by performing the teaching run. 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 or reference direction.

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 the work devices such as the seedling planting device 3 and the wheels 12.

The automatic turning travel control unit 36 controls the aircraft 1 to turn according to a predetermined procedure when the work travel on the straight route IPL is completed and a predetermined manual operation is performed at the turning start position PSR. do. During automatic turning travel, the automatic turning travel control unit 36 may perform control to stop the planting clutch 23 (see FIG. 2) and raise the seedling planting device 3.

Further, the automatic turning travel control section 36 includes a threshold value changing section 38. The threshold value changing unit 38 sets a target direction RD for returning the steering angle during automatic turning based on the turning information 40 stored in the storage unit 29, that is, the turning information 40 acquired by the information acquiring unit 24. The threshold value 45 of the angular difference θ of the traveling direction CD is changed from a preset value. When the threshold value 45 is changed, the threshold value changing unit 38 may notify at least one of the notification unit 26 and the information terminal 5 to that effect.

Even if the steering angle is returned so that the aircraft 1 is traveling straight during a turn, the wheels 12 (front wheels 12A) actually face the straight direction (the steering wheel 10 becomes neutral), and the aircraft 1 does not travel straight until There is a slight time lag during which aircraft 1 moves forward while turning. The distance from when the steering angle is returned to when the aircraft 1 travels straight is affected by the vehicle speed Vr of the aircraft 1 and the size of the aircraft 1, such as its width and wheelbase length. When turning, if the distance from when the steering angle is returned to when the aircraft 1 moves straight varies, it becomes difficult to stably turn the aircraft as expected. Furthermore, if the traveling vehicle speed Vr is too high, the aircraft 1 will slip, and the distance from when the steering angle is returned to when the aircraft 1 will go straight will become longer, making it difficult to stably turn as expected.

Therefore, based on the turning information 40, the threshold value changing unit 38 sets a threshold value 45 of the angular difference θ between the target heading RD and the traveling heading CD for returning the steering angle during automatic turning driving so that an appropriate turning is performed. change. Specifically, the threshold value changing unit 38 increases the threshold value 45 based on the vehicle speed information 40A so that the faster the traveling vehicle speed Vr is, the earlier the steering angle is returned. Note that when the traveling vehicle speed Vr is slow, the distance from when the steering angle is returned to when the aircraft 1 moves straight does not deviate greatly, and the turning does not become a large turn, so there is no need for subsequent correction. may change the threshold value 45 only when the traveling vehicle speed Vr is equal to or higher than a predetermined speed. Further, the threshold value changing unit 38 reads the size of the aircraft 1 from the model information 40B, and increases the threshold value 45 so that the larger the width, wheelbase, etc. of the aircraft 1, the earlier the steering angle is returned. Although the threshold value changing unit 38 can read the size of the aircraft 1 using any method, it stores in advance a correspondence table that describes the relationship between the model and the size of the aircraft 1, and reads the size of the aircraft according to the model information 40B. 1 size can be obtained.

In this way, by changing (optimizing) the threshold value 45 according to the turning information 40, the distance from when the steering angle is returned to when the aircraft 1 goes straight is constant or within an appropriate range, and the distance is stable. Automatic turning can be performed with high precision.

[Automatic turning travel control]
Next, a control flow in automatic turning travel will be described using FIGS. 5 and 6 while referring to FIGS. 1 and 4.

When automatic turning driving is started, first, automatic turning driving control section 36 acquires vehicle speed information 40A detected by vehicle speed detecting section 41 and stored in storage section 29 as turning information 40. Further, the automatic turning travel control unit 36 acquires the model information 40B acquired by the model information acquisition unit 42 and stored in the storage unit 29 as the turning information 40.

Next, the automatic turning travel control unit 36 or the threshold value changing unit 38 determines whether the traveling vehicle speed Vr acquired as the vehicle speed information 40A is greater than a preset reference vehicle speed Vrr (step #1 in FIG. 6).

When the traveling vehicle speed Vr is higher than the reference vehicle speed Vrr (Step #1 in FIG. 6: Yes), the threshold value changing unit 38, based on the traveling vehicle speed Vr (vehicle speed information 40A) and the size of the aircraft 1 acquired from the model information 40B, The threshold value 45 that triggers the return of the steering angle during automatic turning is changed, and the threshold value 45 stored in the storage unit 29 is corrected (step #2 in FIG. 6).

Next, the automatic turning travel control section 36 compares the traveling direction CD of the aircraft 1 at the position PP of the aircraft 1 with the target direction RD, and stores the angular difference θ between the target direction RD and the traveling direction CD in the storage section 29. It is determined whether or not it is less than or equal to the threshold value 45 (step #3 in FIG. 6). Here, the threshold value 45 to be compared is the preset threshold value 45 when the traveling vehicle speed Vr is equal to or lower than the reference vehicle speed Vrr (No in step #1 in FIG. 6), and the threshold value 45 is changed in step #2. If so, it is the changed threshold value 45.

If the angle difference θ is larger than the threshold value 45 (No in step #3 in FIG. 6), the automatic turning travel control unit 36 maintains the steering angle and continues automatic turning travel until the angle difference θ becomes equal to or less than the threshold value 45. do. When the angle difference θ becomes equal to or less than the threshold value 45 (Step #3 in FIG. 6, Yes), the automatic turning travel control unit 36 returns the steering angle to 0 or a predetermined angle (Step #4 in FIG. 6).

Thereafter, the automatic turning travel control unit 36 or the automatic work travel control unit 35 automatically steers the aircraft 1 so that it can automatically travel straight along the next straight route IPL1.

[Another embodiment]
(1) In the above embodiment, the threshold value changing unit 38 changes the threshold value 45 according to the traveling vehicle speed Vr when the traveling vehicle speed Vr during automatic turning travel deviates from the reference vehicle speed Vrr by more than a preset speed. You may. That is, the turning information 40 (vehicle speed information 40A) includes the difference between the traveling vehicle speed Vr and the reference vehicle speed Vrr, and the threshold value changing unit 38 changes the threshold value 45 according to the difference between the traveling vehicle speed Vr and the reference vehicle speed Vrr. You may.

(2) In each of the above embodiments, the threshold value changing unit 38 does not compare the traveling vehicle speed Vr and the reference vehicle speed Vrr, but based on the traveling vehicle speed Vr (vehicle speed information 40A) and the size of the aircraft 1 (model information 40B). , the threshold value 45 may be changed. Furthermore, the traveling vehicle speed Vr may be changed (decelerated) to a predetermined turning vehicle speed at the start of turning travel in automatic travel and manual travel. At this time, in the automatic turning, if the traveling vehicle speed Vr during automatic turning deviates from the turning vehicle speed even though the turning vehicle speed is controlled, the threshold value changing unit 38 changes the traveling vehicle speed Vr (vehicle speed The threshold value 45 may be changed based on the information 40A) and the size of the aircraft 1 (model information 40B). With such a configuration, the relationship between the traveling vehicle speed Vr and the threshold value 45 during cornering can be efficiently optimized, and cornering can be easily and accurately performed.

(3) In each of the embodiments described above, the maximum turning vehicle speed, which is the upper limit traveling vehicle speed Vr set during turning, may be set in advance. Furthermore, the maximum turning vehicle speed may be set based on the positioning accuracy of the positioning unit 8.

The positioning unit 8 acquires positioning data using the Global Satellite Navigation System (GNSS) or the like. There are various types of global satellite navigation systems (GNSS) with different positioning accuracy. For example, DGDS (Differential GPS) has lower positioning accuracy than RTKGDS (Real Time Kinematic GPS). Therefore, controlling automatic turning using the positioning unit 8 that uses DGDS is less accurate than controlling automatic turning using the positioning unit 8 that uses RTKGDS, and is not appropriate when the turning vehicle speed is high. This makes it difficult to control automatic turning.

By setting the maximum turning vehicle speed based on the positioning accuracy of the positioning unit 8, automatic turning travel is performed at a turning vehicle speed corresponding to the positioning accuracy of the positioning unit 8, and automatic turning travel can be performed with high precision.

In this case, the threshold value 45 may be changed based on the traveling vehicle speed Vr (vehicle speed information 40A), but the threshold value 45 may be used in automatic turning without being changed from the preset threshold value 45. good.

(4) In each of the above embodiments, the vehicle speed detection unit 41 may acquire the traveling vehicle speed Vr, which is the vehicle speed information 40A, by any method, but the position PP of the aircraft 1 per unit time acquired from the positioning unit 8 The traveling vehicle speed Vr may be determined from the distance traveled. Thereby, the traveling vehicle speed Vr can be determined with high precision, and automatic turning travel can be performed with high precision.

(5) In each of the embodiments described above, the threshold value changing unit 38 is not limited to the configuration in which the threshold value 45 is changed based on the vehicle speed information 40A and the model information 40B, but the threshold value changing unit 38 is configured to change the threshold value based on either the vehicle speed information 40A or the model information 40B. 45 may be changed. Thereby, automatic turning can be performed more easily.

(6) In each of the above embodiments, the turning information 40 may include various types of information together with the vehicle speed information 40A and the model information 40B, or in place of at least one of the vehicle speed information 40A and the model information 40B. . As such information, various types of work site information including travel information regarding the travel state other than the traveling vehicle speed and viscosity information 40C indicating the viscosity of the field can be considered. Thereby, the threshold value 45 can be changed to a more appropriate value in accordance with the turning operation, and automatic turning operation can be performed with higher accuracy.

For example, in turning, if the field is slippery, the turning radius becomes large. In other words, turning movement is affected by the viscosity of the field. Therefore, a viscosity detection section 43 may be provided as the information acquisition section 24, and viscosity information 40C may be included as the turning information 40. Then, the threshold value changing unit 38 changes the threshold value 45 based on the turning information 40 including the viscosity information 40C.

Further, the model information 40B may include information indicating the type (positioning accuracy) of the positioning system of the positioning unit 8. Then, the threshold value changing unit 38 may change the threshold value 45 in consideration of the positioning accuracy of the positioning unit 8 included in the model information 40B.

(7) In each of the above embodiments, the information acquisition unit 24 is not limited to the turning information 40 during automatic turning travel, but also other traveling information when the rice transplanter (work vehicle) is traveling, and when the work vehicle is working. Various types of control information may be acquired, such as work information when performing the process, environmental information such as information on the work site (field), and the like. Then, the automatic work travel control section 35 or the automatic turning travel control section 36 (control unit 30) sets various types of values other than the threshold value 45 for automatic turning travel according to the one or more pieces of control information acquired by the information acquisition section 24. Control parameters (setting values) may be optimized.

For example, a rice transplanter may travel while connected to a working device, and the external dimensions of the rice transplanter change depending on the connected working device. Further, the vehicle body position, which is the reference for the position PP of the machine body 1, is calculated from positioning data based on the position of the positioning unit 8, and changes depending on the external dimensions of the rice transplanter. Therefore, the model information 40B and the type of the connected working device are acquired as control information, and the control unit 30 may change the vehicle body position based on the acquired control information.

Further, the number of rows, row spacing, etc. in the seedling planting work are determined depending on the connected working device. Therefore, the automatic work travel control unit 35 may set (change) the number of rows and the row spacing in automatic work travel based on control information including the type of work equipment. Further, the threshold value changing unit 38 may acquire the number of rows of the rice transplanter from the model information 40B, and change the threshold value 45 based on the number of rows and the traveling vehicle speed Vr. Further, control parameters (setting values) such as PI gain in automatic driving are determined according to the dimensions of the connected working device. Therefore, the automatic work travel control unit 35 may set (change) control parameters (setting values) such as PI gain in automatic work travel based on control information including the type of work equipment.

Note that if the width of the connected working device is greater than the width of the machine body 1, the turning movement will be affected by the width of the working device. Therefore, the width of the connected working device may be included as the model information 40B. Then, the threshold value changing unit 38 may change the threshold value 45 based on the turning information 40 including the width of the working device.

(8) In each of the above embodiments, the turning procedure in automatic turning travel is not limited to the procedure shown in FIG. 4, but may be any arbitrary procedure. For example, after the steering angle is operated to the maximum and turning travel is started, when the turning angle reaches a predetermined turning angle, the steering angle may be reduced.

(9) 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 that detects obstacles around the body 1 in each of the above embodiments. 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. When at least one of the automatic work travel control section 35 and the automatic turning travel control section 36 detects an obstacle, it controls the travel so as to stop the travel, decelerate the speed, or perform avoidance travel. Then, the automatic work travel control section 35 and the automatic turning travel control section 36 may optimize the distance for detecting obstacles according to the control information.

(10) 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. A program related to software is stored in an arbitrary storage device such as the storage unit 29, and executed by a processor such as a CPU included in the control unit 30 or a separately provided processor. Furthermore, although the control unit 30 may be configured to be mounted on the aircraft body 1, some or all of the functions of the control unit 30 may be provided in the information terminal 5.

(11) 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.

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 8 Positioning unit 12 Wheels (travel device)
24 Information acquisition unit 29 Storage unit 32 Aircraft position calculation unit 33 Route generation unit 36 Automatic turning travel control unit 38 Threshold value change unit 40 Turning information 40A Vehicle speed information 40B Model information 40C Viscosity information 41 Vehicle speed detection unit 42 Model information acquisition unit 43 Viscosity Detection unit 45 Threshold CD Traveling direction IRL Inner circuit route PP Position Vr Traveling vehicle speed Vrr Reference vehicle speed θ Angular difference

Claims (6)

A work vehicle that travels for work in a field by reciprocating along a plurality of straight paths parallel to each other with turning travel in between,
The aircraft and
a traveling device provided on the aircraft;
an aircraft position calculation unit that calculates a position of the aircraft and a running direction of the aircraft;
an information acquisition unit that acquires predetermined turning information during the turning run;
an automatic turning travel control unit that controls the steering angle of the traveling device during the turning travel according to a predetermined procedure,
The automatic turning travel control unit is configured to cause the aircraft to travel straight when, during the turning travel, an angular difference between the target azimuth of the straight route to be traveled subsequent to the turning travel and the travel orientation becomes equal to or less than a predetermined threshold value. control to return the steering angle to
In the work vehicle, the automatic turning travel control unit changes the threshold value according to the turning information. further comprising a storage unit that stores model information of the aircraft,
The information acquisition unit includes a model information acquisition unit that acquires the model information from the storage unit,
The work vehicle according to claim 1, wherein the turning information includes the model information. The work vehicle according to claim 1 or 2, wherein the automatic turning travel control unit changes the traveling vehicle speed of the aircraft body to a predetermined turning vehicle speed at the start of the turning travel. The information acquisition unit includes a viscosity detection unit that detects the viscosity of the field and a vehicle speed detection unit that detects the traveling vehicle speed of the aircraft,
The work vehicle according to claim 1 or 2, wherein the turning information includes viscosity information, which is information on the viscosity, and the traveling vehicle speed during the turning. The information acquisition unit includes a vehicle speed detection unit that detects a traveling vehicle speed of the aircraft,
The automatic turning driving control unit has a reference vehicle speed set in advance for the turning driving,
The work vehicle according to claim 1 or 2, wherein the turning information includes a difference between the traveling vehicle speed and the reference vehicle speed. further comprising a positioning unit that acquires radio waves from a satellite and outputs positioning data for calculating the position of the aircraft,
The automatic turning driving control unit sets a maximum turning vehicle speed that is an upper limit traveling vehicle speed in the turning driving,
The work vehicle according to claim 1 or 2, wherein the maximum turning vehicle speed is set based on the positioning accuracy of the positioning unit.

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