JP7678779B2 - Work vehicle - Google Patents

Description

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

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

JP 2021-185064 A

However, the control parameters (set values) depend on the model, driving conditions, work site conditions, etc., and constant control parameters (set values) do not necessarily provide optimal driving control. For example, when the steering wheel angle is returned to a straight-ahead position while turning, the distance the vehicle travels before the steering wheel returns to a straight-ahead angle or the driving gear returns to straight-ahead driving varies depending on the vehicle speed. For this reason, if the steering angle return level (threshold) is controlled to a constant, it may not be possible to properly transition from turning to straight-ahead driving, depending on the vehicle speed.

The purpose of the present invention is to precisely control driving or work depending on the model, driving conditions, work site conditions, etc.

In order to achieve the above-mentioned object, a work vehicle according to one embodiment of the present invention is a work vehicle that performs work driving in a field by performing round trip driving along multiple straight paths that are parallel to each other with turning drives in between, and is equipped with a body, a traveling device provided on the body, a body position calculation unit that calculates the position of the body and the driving direction of the body, an information acquisition unit that acquires specified turning time information during the turning drive, and an automatic turning drive control unit that controls the turning steering of the traveling device during the turning drive in a predetermined procedure, and during the turning drive started with the specified turning steering , when the angle difference between the target direction of the straight path traveled following the turning drive and the driving direction becomes equal to or less than a specified threshold value, the automatic turning drive control unit controls the predetermined turning steering to be returned to its original state so that the body travels straight ahead, and the automatic turning drive control unit changes the threshold value in accordance with the turning time information to direct the vehicle to the next straight path .

Automatic turning is performed according to a set procedure so that turning ends at a set position. Turning is affected by factors such as the vehicle speed during turning, the state of the field, and the state of the machine, such as the width of the machine, and as a result, the planned turning may not be achieved.

According to the above configuration, any information such as vehicle speed can be acquired as turning information during automatic turning, and the threshold for terminating turning can be changed according to the turning information. This makes it possible to terminate automatic turning under appropriate conditions according to the turning information, and to control automatic turning with high precision.

The device may further include a storage unit that stores model information of the aircraft, and 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, turning is affected by factors such as the width of the aircraft, which can be read from the model information. With the above configuration, automatic turning can be terminated under appropriate conditions depending on factors such as the width of the aircraft, allowing automatic turning to be controlled with high precision.

The automatic turning control unit may also change the vehicle speed of the vehicle to a predetermined turning speed when the turning operation starts.

This configuration allows the vehicle to automatically turn at a vehicle speed that is expected to allow for proper turning, and allows the vehicle to automatically turn with high precision.

The information acquisition unit may include a viscosity detection unit that detects the viscosity of the field and a vehicle speed detection unit that detects the vehicle speed of the vehicle, and the turning information may include viscosity information that is information about the viscosity and the vehicle speed during the turning movement.

As mentioned above, turning is affected by the machine body skidding due to the viscosity of the field. With the above configuration, automatic turning can be terminated under appropriate conditions according to the viscosity of the field, and automatic turning can be controlled with high precision.

In addition, turning is affected by the vehicle speed during turning. With the above configuration, automatic turning can be terminated under appropriate conditions depending on the vehicle speed, and automatic turning can be controlled with high precision.

The information acquisition unit may also include a vehicle speed detection unit that detects the vehicle speed of the vehicle, and the automatic turning control unit may have a reference vehicle speed for the turning drive set in advance, and may include the difference between the vehicle speed and the reference vehicle speed as the turning information.

With this configuration, the vehicle speed that affects turning can be determined based on the reference vehicle speed. This makes it easy to determine the need to change the threshold value, and when necessary, automatic turning can be terminated under appropriate conditions according to the vehicle speed. As a result, automatic turning can be controlled with high precision.

The vehicle may further include a positioning unit that receives radio waves from a satellite and outputs positioning data for calculating the position of the vehicle, and the automatic turning control unit sets a maximum turning speed that is the upper limit of the vehicle speed during turning, and the maximum turning 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. With the above configuration, the maximum turning speed during turning can be set according to the positioning accuracy of the positioning unit. Therefore, automatic turning can be controlled with high precision according to the positioning accuracy of the positioning unit.

FIG. 1 is a left side view illustrating the overall configuration of a rice transplanter. FIG. 1 is a plan view illustrating an example of the overall configuration of a rice transplanter. FIG. FIG. 11 is a diagram illustrating an example of an automatic turning travel procedure. FIG. 2 is a diagram illustrating an example of a functional configuration for controlling automatic driving. FIG. 11 is a diagram illustrating an example of a flow of automatic turning traveling.

Below, we will explain a rice transplanter that travels through farm fields as an example of a work vehicle.

For ease of understanding, in this embodiment, unless otherwise specified, "front" (the direction of arrow F shown in Figs. 1 and 2) means the front in the fore-and-aft direction (travel direction) of the aircraft, and "rear" (the direction of arrow B shown in Figs. 1 and 2) means the rear in the fore-and-aft direction (travel direction) of the aircraft. Furthermore, the left-right or lateral direction means the transverse direction of the aircraft (aircraft width direction) perpendicular to the fore-and-aft direction of the aircraft, and "left" (the direction of arrow L shown in Fig. 2) and "right" (the direction of arrow R shown in Fig. 2) mean the leftward and rightward directions of the aircraft 1, respectively.

[Overall structure]
1 and 2, the rice transplanter includes a riding type four-wheel drive machine body 1. The machine body 1 includes a link mechanism 13 in the form of a parallel four-linkage connected to the rear of the machine body 1 so as to be able to rise and fall and swing, a hydraulic lifting link 13a that drives the link mechanism 13 to swing, and a seedling planting device 3 that is connected to the rear end region of the link mechanism 13 so as to be able to roll. The seedling planting device 3 is an example of a working device, and a fertilizer applicator, a chemical spraying device, etc. may be mounted as other working devices.

The machine body 1 is equipped with wheels 12 (corresponding to the "travel device") as a mechanism for traveling, an engine 2, and a hydraulic continuously variable transmission 9 as the 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 angle of the motor swash plate and the pump swash plate. The wheels 12 have left and right front wheels 12A that can be steered, and left and right rear wheels 12B that cannot be steered. The engine 2 and the continuously variable transmission 9 are mounted at the front of the machine 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, etc.

As an example, the seedling planting device 3 is configured for eight rows of planting. The seedling planting device 3 is equipped with a seedling loading platform 21, eight rows of planting mechanisms 22, five floats 15, etc. The seedling planting device 3 can be changed to two-row, four-row, six-row, etc. planting formats by controlling each row clutch (planting clutch 23).

The seedling loading platform 21 is a platform on which eight mat-shaped seedlings are placed. The seedling loading platform 21 moves back and forth 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 loading platform 21 reaches the left or right stroke end, each mat-shaped seedling on the seedling loading platform 21 is vertically fed at a predetermined pitch toward the bottom end of the seedling loading platform 21.

The eight planting mechanisms 22 are rotary type and are arranged in the left-right direction at regular intervals corresponding to the spacing between the planting rows. Each planting mechanism 22 receives driving force from the engine 2 when the planting clutch 23 is switched to a transmission state, and cuts one seedling from the bottom end of each mat-like seedling placed on the seedling platform 21 and plants it in the muddy soil after leveling. This allows the seedling planting device 3 to remove seedlings from the mat-like seedlings placed on the seedling platform 21 and plant them in the muddy soil of the paddy field.

The floats 15 level the field when planting seedlings. Each float 15 is associated with two rows of planting mechanisms 22.

The machine body 1 is equipped with a driving section 14 in its rear side area. The driving section 14 is equipped with a steering wheel 10 for steering the front wheels, a main speed change lever 7 for adjusting the vehicle speed by changing the speed of the continuously variable transmission 9, a work operation lever 11 for raising and lowering the seedling planting device 3 and for turning the planting clutch 23 on and off (switching between a transmission state and a non-transmission state), and a driver's seat 16 for the operator (driver/worker). The steering wheel 10, main speed change lever 7, and work operation lever 11 are provided on the driver's panel 6 in front of the driver's seat 16. Furthermore, in front of the driving section 14, a spare seedling storage device 17A for storing spare seedlings is supported on a spare seedling support frame 17.

The spare seedling support frame 17 is also provided with a positioning unit 8. The positioning unit 8 outputs positioning data for calculating the position PP (see FIG. 4) and orientation of the vehicle 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 inclination and acceleration of the three axes of the vehicle 1.

[Work trip]
The travel of the rice transplanter when performing rice planting work in a farm field will be described with reference to Figs. 1 and 2 and Fig. 3 .

The rice transplanter in this embodiment can selectively perform manual driving and automatic driving. In manual driving, the driver manually operates the driving operation tools such as the steering wheel 10, the main shift lever 7, and the work operation lever 11 to perform work driving. In automatic driving, the rice transplanter drives and works under automatic control, and performs straight work driving along the straight path IPL described below, with turning driving in between. In this case, the turning driving is automatically controlled according to a predetermined procedure, without a driving path being generated.

When the rice transplanter is planting, the field is divided into an outer area OA and an inner area IA, and the machine travels in each area accordingly.

In the internal area IA, multiple straight-line paths IPL (internal round-trip paths) that are approximately parallel to one side of the field are generated. The straight-line paths IPL are travel paths that travel throughout the entire internal area IA, and each straight-line path IPL travels back and forth with turning travel in between. Each time a turning travel is performed, the next straight-line path IPL to be traveled is generated in sequence. In addition, each straight-line path IPL has a target orientation RD (see FIG. 4) for automatic travel (straight-ahead travel) along the straight-line path IPL.

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

[Automatic turning]
Next, automatic turning will be described with reference to FIG. 4 while also referring to FIG. 1 and FIG.

Automatic turning is initiated by a specific manual operation. Automatic turning is performed in the outer peripheral area OA, particularly in an area inside the field that is a specific distance from the ridge RW. Automatic turning is not performed along a travel path, but is performed in a predetermined procedure by controlling the travel devices such as the wheels 12 in a specific procedure.

For example, when the work drive on the straight path IPL ends and a predetermined manual operation is performed at the turn start position PSR, the front wheels 12A (traveling device) are first operated to a predetermined steering angle, for example, the maximum steering angle, to perform the automatic turning drive. During the turning drive, the driving direction CD of the vehicle 1 at the position PP of the vehicle 1 is continuously or successively acquired.

During automatic turning, the target orientation RD of the (next) straight path IPL1 to be traveled after the turn is completed is compared with the travel orientation CD. Next, when the angle difference θ between the target orientation RD and the travel orientation CD becomes equal to or less than a predetermined threshold value 45 (see FIG. 5), the steering angle is returned so that the vehicle 1 travels straight ahead (the steering angle is set to 0).

After that, automatic driving control is performed so that the vehicle travels along the straight-line path IPL1. This transitions the automatic driving control from automatic turning driving to automatic straight-line driving.

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

The operation and travel of the rice transplanter during automatic travel is controlled by a control unit 30 equipped with a processor such as a CPU, based on various control parameters (set values). The control unit 30 is connected to the positioning unit 8, the information acquisition unit 24, the obstacle detection device 28, the memory unit 29, the wheels 12 which are the travel device, the notification unit 26, and the information terminal 5 in a state in which data communication is possible via a communication unit (not shown) etc.

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

The information acquisition unit 24 acquires various information acquired during automatic turning travel as turning time information 40. The turning time information 40 is vehicle speed information 40A, which is information on the traveling vehicle speed Vr of the machine body 1 (see FIG. 6), and model information 40B related to the model. The information acquisition unit 24 includes a vehicle speed detection unit 41 and a model information acquisition unit 42. The vehicle speed detection unit 41 acquires the traveling vehicle speed Vr of the machine body 1 as vehicle speed information 40A and stores it in the storage unit 29 described below. The model information acquisition unit 42 acquires model information 40B of the machine body 1 and stores it in the storage unit 29 described below. The model information 40B may be input and stored in the initial setting before the rice transplanter travels, or may be stored in the storage unit 29 in advance (such as when the machine body 1 is shipped).

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

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

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

The vehicle position calculation unit 32 intermittently or continuously calculates the position PP and driving direction CD of the vehicle 1 in the field based on the positioning data received from the positioning unit 8.

By performing teaching driving, the path generation unit 33 calculates at least one of a base line and a reference direction for generating a straight line path IPL. Then, the path generation unit 33 uses the calculated base line or reference direction to generate the next straight line path IPL to be traveled each time a turning drive is performed.

The automatic work driving control unit 35 controls the automatic work driving along the straight line path IPL based on the position PP of the machine body 1 while controlling the work equipment such as the seedling planting device 3 and the wheels 12.

When the work run on the straight path IPL ends and a predetermined manual operation is performed at the start of the run position PSR, the automatic turning and running control unit 36 controls the machine body 1 to turn in a predetermined procedure. During the automatic running, the automatic turning and running control unit 36 may stop the planting clutch 23 (see FIG. 2) and perform control to raise the seedling planting device 3.

The automatic turning control unit 36 also includes a threshold change unit 38. The threshold change unit 38 changes the threshold 45 of the angle difference θ between the target direction RD and the driving direction CD for returning the steering angle during automatic turning, from a preset value, based on the turning information 40 stored in the memory unit 29, i.e., the turning information 40 acquired by the information acquisition unit 24. When the threshold 45 is changed, the threshold change unit 38 may notify at least one of the notification unit 26 and the information terminal 5 of the change.

Even if the steering angle is returned to the vehicle 1 during a turn so that the vehicle 1 travels straight, there is a slight time lag before the wheels 12 (front wheels 12A) actually face in the straight direction (the steering wheel 10 becomes neutral) and the vehicle 1 travels straight, during which time the vehicle 1 moves forward while turning. The distance from when the steering angle is returned to when the vehicle 1 travels straight is affected by the vehicle speed Vr of the vehicle 1 and the size of the vehicle 1, such as the width and wheelbase length of the vehicle 1. If the distance from when the steering angle is returned to when the vehicle 1 travels straight varies during a turn, it becomes difficult to make a stable turn as expected. Also, if the vehicle speed Vr is too fast, the vehicle 1 will slip, and the distance from when the steering angle is returned to when the vehicle 1 travels straight will be long, making it difficult to make a stable turn as expected.

Therefore, the threshold change unit 38 changes the threshold value 45 of the angle difference θ between the target direction RD and the driving direction CD for returning the steering angle during automatic turning travel based on the turning time information 40 so that appropriate turning is performed. Specifically, the threshold change unit 38 increases the threshold value 45 based on the vehicle speed information 40A so that the steering angle is returned earlier as the driving vehicle speed Vr is faster. Note that when the driving vehicle speed Vr is slow, the distance from returning the steering angle to the vehicle 1 going straight is not significantly different, and the turning does not become a large turn, so no subsequent correction is required. Therefore, the threshold change unit 38 may change the threshold value 45 only when the driving vehicle speed Vr is a predetermined speed or higher. In addition, the threshold change unit 38 reads the size of the vehicle 1 from the model information 40B, and increases the threshold value 45 so that the steering angle is returned earlier as the size of the width, wheelbase, etc. of the vehicle 1 is larger. The threshold change unit 38 can read the size of the machine 1 using any method, but it can also store in advance a correspondence table that describes the relationship between the model and the size of the machine 1, and obtain the size of the machine 1 according to the model information 40B.

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 until the aircraft 1 starts moving straight is constant or within an appropriate range, enabling stable and accurate automatic turning.

[Automatic turning control]
Next, a control flow in automatic turning will be described with reference to FIGS. 5 and 6 while also referring to FIGS.

When automatic turning is started, the automatic turning control unit 36 first acquires the vehicle speed information 40A detected by the vehicle speed detection unit 41 and stored in the memory unit 29 as turning information 40. The automatic turning control unit 36 also acquires the model information 40B acquired by the model information acquisition unit 42 and stored in the memory unit 29 as turning information 40.

Next, the automatic turning control unit 36 or the threshold change 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).

If the traveling vehicle speed Vr is greater than the reference vehicle speed Vrr (step #1 in FIG. 6: Yes), the threshold change unit 38 changes the threshold 45 that triggers the return of the steering angle during automatic turning based on the traveling vehicle speed Vr (vehicle speed information 40A) and the size of the vehicle 1 obtained from the model information 40B, and corrects the threshold 45 stored in the memory unit 29 (step #2 in FIG. 6).

Next, the automatic turning control unit 36 compares the driving direction CD of the vehicle 1 at the position PP of the vehicle 1 with the target direction RD, and determines whether the angle difference θ between the target direction RD and the driving direction CD is equal to or less than the threshold value 45 stored in the memory unit 29 (step #3 in FIG. 6). Here, the threshold value 45 to be compared is the preset threshold value 45 when the driving vehicle speed Vr is equal to or less than the reference vehicle speed Vrr (step #1 No in FIG. 6), and is the changed threshold value 45 when the threshold value 45 has been changed in step #2.

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

Then, the automatic turning driving control unit 36 or the automatic work driving control unit 35 performs automatic steering control of the vehicle 1 so that the vehicle can automatically drive straight along the next straight-line route IPL1.

[Another embodiment]
(1) In the above embodiment, when the traveling vehicle speed Vr during automatic turning travel deviates from the reference vehicle speed Vrr by a preset speed or more, the threshold changing unit 38 may change the threshold 45 in accordance with the traveling vehicle speed Vr. In other words, the turning information 40 (vehicle speed information 40A) may include the difference between the traveling vehicle speed Vr and the reference vehicle speed Vrr, and the threshold changing unit 38 may change the threshold 45 in accordance with the difference between the traveling vehicle speed Vr and the reference vehicle speed Vrr.

(2) In each of the above embodiments, the threshold change unit 38 may change the threshold 45 based on the traveling vehicle speed Vr (vehicle speed information 40A) and the size of the vehicle body 1 (model information 40B) without comparing the traveling vehicle speed Vr with the reference vehicle speed Vrr. In addition, the traveling vehicle speed Vr may be changed (decelerated) to a predetermined turning vehicle speed at the start of turning in automatic driving and manual driving. In this case, in the automatic turning driving, even if the turning vehicle speed is controlled, if the traveling vehicle speed Vr during the automatic turning driving deviates from the turning vehicle speed, the threshold change unit 38 may change the threshold 45 based on the traveling vehicle speed Vr (vehicle speed information 40A) and the size of the vehicle body 1 (model information 40B). With this configuration, the relationship between the traveling vehicle speed Vr during turning driving and the threshold 45 can be efficiently optimized, and turning driving can be performed easily and accurately.

(3) In each of the above embodiments, a maximum turning vehicle speed, which is the upper limit of the vehicle speed Vr 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 from a Global Navigation Satellite System (GNSS) or the like. There are various types of Global Navigation Satellite Systems (GNSS) with different positioning accuracy. For example, DGDS (Differential GPS) has lower positioning accuracy than RTKGDS (Real Time Kinematic GPS). Therefore, control of automatic turning using a positioning unit 8 that uses DGDS is less accurate than control of automatic turning using a positioning unit 8 that uses RTKGDS, and appropriate control of automatic turning becomes difficult when the turning vehicle speed increases.

By setting the maximum turning speed based on the positioning accuracy of the positioning unit 8, automatic turning can be performed at a turning speed that corresponds to the positioning accuracy of the positioning unit 8, allowing automatic turning to be performed with high accuracy.

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.

(4) In each of the above embodiments, the vehicle speed detection unit 41 may obtain the traveling vehicle speed Vr, which is the vehicle speed information 40A, by any method, but the traveling vehicle speed Vr may also be obtained from the distance traveled by the position PP of the vehicle 1 per unit time obtained from the positioning unit 8. This allows the traveling vehicle speed Vr to be obtained with high accuracy, and automatic turning can be performed with high accuracy.

(5) In each of the above embodiments, the threshold change unit 38 is not limited to a configuration in which the threshold change unit 38 changes the threshold 45 based on the vehicle speed information 40A and the model information 40B, but may change the threshold 45 based on either the vehicle speed information 40A or the model information 40B. This makes it easier to perform automatic turning.

(6) In each of the above embodiments, the turning information 40 may include various information in addition to 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. Such information may include driving information related to the driving state other than the vehicle speed, various types of work site information including viscosity information 40C indicating the viscosity of the field, and the like. This allows the threshold value 45 to be changed to a more appropriate value in accordance with the turning driving, allowing automatic turning driving to be performed with greater accuracy.

For example, when turning, if the field is slippery, the turning radius becomes larger. In other words, turning is affected by the viscosity of the field. For this reason, a viscosity detection unit 43 may be provided as the information acquisition unit 24, and viscosity information 40C may be included as the turning information 40. The threshold change unit 38 then changes the threshold 45 based on the turning information 40 including the viscosity information 40C.

The model information 40B may also include information indicating the type (positioning accuracy) of the positioning system of the positioning unit 8. The threshold change unit 38 may then change the threshold 45 taking into account 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 may acquire various control information, such as not only turning information 40 during automatic turning travel, but also other travel information when the rice transplanter (work vehicle) travels, work information when the work vehicle works, and environmental information such as information on the work site (field). The automatic work travel control unit 35 or the automatic turning travel control unit 36 (control unit 30) may optimize various control parameters (setting values) other than the threshold value 45 in the automatic turning travel in accordance with one or more pieces of control information acquired by the information acquisition unit 24.

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

In addition, the number of rows and row spacing in seedling planting work are determined according to the connected work equipment. Therefore, the automatic work travel control unit 35 may set (change) the number of rows and row spacing in automatic work travel based on control information including the type of work equipment. Furthermore, the threshold change unit 38 may obtain the number of rows of the rice transplanter from the model information 40B and change the threshold 45 based on the number of rows and the travel vehicle speed Vr. In addition, control parameters (setting values) such as PI gain in automatic travel are determined according to the dimensions of the connected work equipment. 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.

When the width of the connected work device is greater than the width of the machine body 1, turning is affected by the width of the work device. Therefore, the width of the connected work device may be included in the model information 40B. The threshold change unit 38 may change the threshold 45 based on the turning information 40 including the width of the work device.

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

(9) When the automatic driving starts or during automatic driving, if there is an obstacle in front of the vehicle in the direction of travel or around the vehicle 1, problems may occur with driving or work. Therefore, the rice transplanter of this embodiment may be equipped with a sonar sensor as an example of the obstacle detection device 28 that detects obstacles around the vehicle 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 can also be configured to detect obstacles during manual driving. At least one of the automatic work driving control unit 35 and the automatic turning driving control unit 36 controls driving so that, when an obstacle is detected, driving is stopped, decelerated, or avoided. Then, the automatic work driving control unit 35 and the automatic turning driving control unit 36 may optimize the distance at which obstacles are detected according to the control information.

(10) In each of the above embodiments, the control unit 30 is not limited to being composed of the above-mentioned functional blocks, and may be composed of any functional blocks. For example, each functional block of the control unit 30 may be further subdivided, or conversely, some or all of the functional blocks may be combined. In addition, 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. In addition, some or all of the functions of the control unit 30 may be composed of software. A program related to the software is stored in any storage device such as the storage unit 29, and is executed by a processor such as a CPU provided in the control unit 30, or a processor provided separately. In addition, the control unit 30 may be configured to be mounted on the aircraft 1, but 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 running device is not limited to wheels 12 and may be any running device such as crawlers.

The present invention can be applied to rice transplanters, agricultural work vehicles that travel around fields while making turns, and various other work vehicles that travel around work sites while making turns.

1 Airframe 8 Positioning unit 12 Wheels (running gear)
24 Information acquisition unit 29 Memory unit 32 Aircraft position calculation unit 33 Route generation unit 36 Automatic turning driving control unit 38 Threshold 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 Travel direction IRL Inner circuit path PP Position Vr Traveling vehicle speed Vrr Reference vehicle speed θ Angle difference

Claims (7)

A work vehicle that performs work travel in a field by performing reciprocating travel along a plurality of straight paths that are parallel to each other with turning travel in between,
The aircraft and
A running device provided on the airframe;
an aircraft position calculation unit that calculates the position of the aircraft and the traveling direction of the aircraft;
An information acquisition unit that acquires predetermined turning information during the turning travel;
an automatic turning control unit that controls turning steering of the traveling device during the turning travel in a predetermined procedure;
the automatic turning control unit performs control to return the predetermined turning steering to its original state so that the vehicle travels straight ahead when an angular difference between a target orientation of the straight path traveled following the turning traveling and the traveling orientation becomes equal to or less than a predetermined threshold during the turning traveling started by a predetermined turning steering ,
The automatic turning control unit changes the threshold value in accordance with the turning information to direct the vehicle to the next straight path . A storage unit for storing model information of the aircraft is further provided,
a model information acquisition unit that acquires the model information from the storage unit as the information acquisition unit;
The work vehicle according to claim 1 , wherein the turning information includes model information. The work vehicle according to claim 1 or 2, wherein the automatic turning control unit changes the vehicle speed of the vehicle body to a predetermined turning vehicle speed when the turning operation starts. 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 speed of the vehicle;
3. The work vehicle according to claim 1, wherein the turning information includes viscosity information that is information about the viscosity and the vehicle speed during the turning travel. The information acquisition unit includes a vehicle speed detection unit that detects a traveling vehicle speed of the vehicle;
The automatic turning control unit is configured to set a reference vehicle speed in the turning motion in advance,
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. A positioning unit is further provided which receives radio waves from a satellite and outputs positioning data for calculating the position of the aircraft.
The automatic turning travel control unit sets a maximum turning vehicle speed which is an upper limit of a traveling vehicle speed during the turning travel,
3. The work vehicle according to claim 1, wherein the maximum turning speed is set based on the positioning accuracy of the positioning unit. The work vehicle according to claim 1 , wherein the threshold value is changed during the turning movement.

Images