Work vehicle

Abstract

To provide a work vehicle that can perform work while always maintaining an appropriate distance between the work vehicle and a dike.SOLUTION: A work vehicle includes: a traveling body 10; steering wheels 40L, 40R attached to the traveling body 10; a control unit 200 for causing the traveling body 10 to travel autonomously; a first dike detection sensor 621A for detecting a distance from a front part of the traveling body 10 to a dike, which is provided on a front side surface of the traveling body; and a second dike detection sensor 621B for detecting a distance from a rear part of the traveling body to the dike, which is provided on a rear side surface of the traveling body 10. The control unit 200 automatically steers the traveling body 10 to travel along the dike on the basis of detection results of the first dike detection sensor 621A and the second dike detection sensor 621B.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a work vehicle such as a tractor.

Background Art

[0002] There is known a work vehicle having a positioning device for measuring the self-position of a traveling vehicle body, a work implement recognition means for recognizing a work implement mounted on the vehicle, and a control unit for autonomously traveling along a preset planned travel route. When the obstacle recognition means for recognizing an obstacle existing in the traveling direction recognizes an obstacle within the planned travel route, the control unit changes the travel route according to the mounted work implement and avoids the obstacle. (Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the above conventional work vehicle, the position of the traveling vehicle body was measured by a positioning device. When an obstacle was recognized while traveling near the edge of a preset planned travel route, an avoidance operation was performed and the vehicle returned to the planned travel route. However, since the positioning device has a slight deviation from the actual position, the distance from the edge has widened and residual tillage remains. An object of the present invention is to provide a work vehicle that can perform work while always maintaining an appropriate distance from the edge.

Means for Solving the Problems

[0005] In order to solve the above-described problems, the present invention is configured as follows.

[0006] The invention according to claim 1 is characterized in that it includes a traveling vehicle body (10), steering wheels (40L, 40R) attached to the traveling vehicle body (10), a control unit (200) for autonomously driving the traveling vehicle body (10), a first ridge detection sensor (621A) for detecting the distance from the front of the traveling vehicle body (10) to the ridge provided on the front side surface of the traveling vehicle body, a second ridge detection sensor (621B) for detecting the distance from the rear of the traveling vehicle body to the ridge provided on the rear side surface of the traveling vehicle body (10), and automatically controls the traveling vehicle body (10) to travel along the ridge based on the detection results of the first ridge detection sensor (621A) and the second ridge detection sensor (621B).

[0007] The invention according to claim 2 is characterized in that when the distance from the first ridge detection sensor (621A) to the ridge is within a specified range and the distance from the second ridge detection sensor (621B) to the ridge is also within a specified range, the control unit (200) automatically controls the vehicle to go straight ahead.

[0008] The invention according to claim 3 is characterized in that when the control unit (200) detects that the distance from the first ridge detection sensor (621A) to the ridge is more than a specified range away and the distance from the second ridge detection sensor (621B) to the ridge is within a specified range, the control unit rotates the steering wheels (40L, 40R) in the direction of the ridge and automatically controls the vehicle so that the distance from the first ridge detection sensor to the ridge is within the specified range.

[0009] The invention according to claim 4 is characterized in that when the control unit (200) detects that the distance from the first ridge detection sensor (621A) to the ridge is within a specified range and the distance from the second ridge detection sensor (621B) to the ridge is more than a specified range away, the control unit rotates the steering wheels (40L, 40R) in the direction opposite to the ridge and automatically controls the vehicle so that the distance from the second ridge detection sensor to the ridge is within the specified range.

[0010] The invention according to claim 5 is characterized in that when the control unit (200) detects that the distance from the first edge detection sensor to the edge has approached within a specified range and the distance from the second edge detection sensor (621B) to the edge is within the specified range, the steering wheels (40L, 40R) are rotated in the direction opposite to the edge, and automatic steering is performed so that the distance from the first edge detection sensor (621A) to the edge falls within the specified range.

[0011] The invention according to claim 6 is characterized in that when the control unit (200) detects that the distance from the first edge detection sensor (621A) to the edge is within the specified range and the second edge detection sensor (621B) detects that the distance to the edge has approached within a specified range, the steering wheels (40L, 40R) are rotated in the direction of the edge, and automatic steering is performed so that the distance from the second edge detection sensor (621B) to the edge falls within the specified range.

[0012] The invention according to claim 7 is characterized in that width information of the working machine (11) mounted on the traveling vehicle body (10) is acquired, and a predetermined range of the distances from the first edge detection sensor and the second edge detection sensor to the edge is set based on the width information.

Advantages of the Invention

[0013] Accordingly, since the edge detection sensor (621) measures the distance to the edge and performs automatic steering based on the detection result, autonomous travel can be achieved while maintaining a certain distance along the edge without setting based on field data. Further, since the outer shape information can be calculated depending on whether the working machine (11) is mounted or not and the type of the working machine (11), contact with the edge can be avoided and autonomous travel can be achieved along the edge.

Brief Description of the Drawings

[0014]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Modes for Carrying Out the Invention

[0015] Hereinafter, embodiments of the present invention will be described with reference to examples shown in the drawings. In the description of the examples, the left and right directions are referred to as left and right respectively toward the forward direction of the vehicle body, and the forward direction is referred to as front and the reverse direction is referred to as rear. However, this does not limit the configuration of the present invention.

[0016] An agricultural robot tractor will be described as an autonomous driving work vehicle.

[0017] First, the basic configuration and operation of the agricultural robot tractor of the present embodiment will be described. Regarding the configuration and operation related to the control unit 200 and the like, they will be described in detail later.

[0018] In the overall configuration of FIGS. 1 and 2, an engine 30 is provided inside the bonnet 31 at the front of the traveling vehicle body 10. The rotational power of the engine 30 is transmitted through various power transmission mechanisms inside the transmission case provided below the floor 21 of the driving unit 20. More specifically, in FIG. 3, the rotational power shifted by the main transmission 120 and the sub-transmission 130 is transmitted to the left front wheel 40L and the right front wheel 40R, as well as the left rear wheel 50L and the right rear wheel 50R.

[0019] On the left side of the floor 21, a brake pedal connection release pedal and a clutch pedal are arranged.

[0020] On the right side of the floor 21, as shown in FIG. 3, a left brake pedal 411L and a right brake pedal 411R, as well as an accelerator pedal are arranged. Further, a driver's seat 15 is provided inside the driving unit 20, and a steering wheel 16 for steering the left front wheel 40L and the right front wheel 40R, which are steering wheels, is provided in front of the driver's seat 15.

[0021] At the rear of the traveling vehicle body 10, a working machine 11 such as a tilling device having a body width wider than that of the traveling vehicle body 10 is mounted using a three-point link mechanism.

[0022] The rotational power of the engine 30 is transmitted to the left rear wheel 50L and the right rear wheel 50R via the forward and reverse clutch 110, the main transmission 120, the auxiliary transmission 130, and the rear wheel differential gear 312. When 4WD (4-Wheel Drive) driving is performed, the rotational power of the engine 30 is also transmitted to the left front wheel 40L and the right front wheel 40R via the forward and reverse clutch 110, the main transmission 120, the auxiliary transmission 130, the 4WD clutch 320, and the front wheel differential gear 311.

[0023] In FIG. 3, when an operator is on board, the left brake device 400L is a device that brakes the left rear wheel 50L according to the state of the left brake cylinder 412L that operates by stepping on the left brake pedal 411L, and the right brake device 400R is a device that brakes the right rear wheel 50R according to the state of the right brake cylinder 412R that operates by stepping on the right brake pedal 411R.

[0024] Also, when performing autonomous driving, the states of the left brake cylinder 412L and the right brake cylinder 412R are changed according to an instruction from the travel control unit of the control unit 200 (FIG. 4). The instruction from the travel control unit is performed using the single brake valve 420, the both brake valves 431 and 432, the left brake valve 441L and the left brake solenoid 442L, the right brake valve 441R and the right brake solenoid 442R, the proportional valve 450, the relief valve 460, and the pump 470.

[0025] The turning angles of the left front wheel 40L and the right front wheel 40R, which are steering wheels, are performed according to the state of the steering cylinder 330, which is a steering device. The state of the steering cylinder 330 is changed according to an instruction from the control unit 200.

[0026] The control unit 200 includes a tillage implement lift control unit, an engine control unit, and a travel control unit that operate in cooperation with a memory, a timer, and the like.

[0027] The detected values of the brake pedal depression sensor, the steering angle sensor 340, the vehicle speed sensor 350, the forward sensor, the reverse sensor, the main transmission switch, the forward pressure sensor, and the reverse pressure sensor are input to the travel control unit of the control unit 200. Then, the travel control unit controls the forward and reverse clutch 110, the main transmission 120, and the left brake cylinder 412L and the right brake cylinder 412R based on the input detected values.

[0028] Next, with reference mainly to FIGS. 1, 2, 4 to 6, the control and operation of the agricultural robot tractor will be described more specifically.

[0029] Here, FIG. 4 is a control block diagram of the control system of the agricultural robot tractor according to the embodiment of the present invention.

[0030] The traveling vehicle body position measuring mechanism 500 is a mechanism for measuring the position of the traveling vehicle body 10.

[0031] In the present embodiment, the traveling vehicle body position measuring mechanism 500 includes a satellite positioning unit.

[0032] In the embodiment of the modification, the traveling vehicle body position measuring mechanism 500 may include a triangulation mechanism.

[0033] The steering angle sensor 340 is a sensor for detecting the steering angle.

[0034] In the present embodiment, the steering angle sensor 340 is a sensor attached to the side of the left front wheel 40L.

[0035] In the embodiment of the modification, the steering angle sensor 340 may be a sensor attached to the side of the right front wheel 40R or a sensor attached to the side of the steering cylinder 330.

[0036] In this embodiment, the obstacle detection mechanism 600 has two front ultrasonic sensors 610 as obstacle detection means.

[0037] The front ultrasonic sensor 610 is a sensor whose detection range A1 is the range in front of the traveling vehicle body 10.

[0038] When the presence of an obstacle in the detection range A1 of the front ultrasonic sensor 610 is recognized based on the feedback time of the ultrasonic wave reflected by the obstacle, an alarm is issued as an obstacle avoidance means and the traveling vehicle body 10 is automatically stopped.

[0039] The stacked indicator lamp 601 is an indicator lamp for notifying the outside of the operating state of the obstacle detection mechanism 600 and the like.

[0040] In this embodiment, an operation state check mode of the obstacle detection mechanism 600 is provided, which can be used without a special monitoring device or inspection device so that an operator can visually confirm the operation state of the obstacle detection mechanism 600 based on the lighting pattern of the stacked indicator lamp 601.

[0041] For example, in the operation state check mode, if the lighting pattern of the stacked indicator lamp 601 that individually outputs the detection states of a plurality of sensors changes according to the position of an operator walking around the periphery of the traveling vehicle body 10, it is determined that the operation state of the obstacle detection mechanism 600 is normal.

[0042] Each time the key switch of the engine 30 is turned on, the operation state check mode must be executed before the start of the automatic driving control, and the safety in the automatic driving control is improved.

[0043] During the tilling operation at the edge of a paddy field by a robot tractor, a first paddy field detection sensor 621A is provided on the side of the bonnet 31 of the traveling vehicle body 10 and a second paddy field detection sensor 621B is provided on the rear fender as paddy field detection means so as to accurately detect the distance between the paddy field and the vehicle.

[0044] The side detection sensor 621 is composed of sensors whose detection range A2L is the range on the side of the traveling vehicle body 10.

[0045] Figs. 5 and 6 are explanatory diagrams of the traveling route.

[0046] Fig. 6 consists of a straight traveling route Cs, a turning route Ct connecting two adjacent straight traveling routes Cs, a headland traveling route Ch, and entrances / exits 13 and 14, and is configured such that the traveling vehicle body 10 can enter and exit through the entrances / exits. The control unit 200 performs automatic traveling control for traveling the traveling vehicle body 10 along a preset traveling route C based on the settings of the agricultural robot tractor and the working machine 11, instructions from the remote controller 201, the satellite positioning system, the obstacle detection results of the obstacle detection mechanism 600, the detection results of the side detection sensor 621, and the like.

[0047] Specifically, when the traveling vehicle body 10 enters the straight traveling route Cs from the field end point P1 at the corner of the straight traveling route Cs, it travels straight to the field end point Q1 at the opposite position, once exits the straight traveling route Cs and then turns on the headland, and enters the straight traveling route Cs again from the adjacent field end point Q2. After that, it travels straight to the field end point P2 at the opposite position, exits the straight traveling route Cs and then turns on the headland, and enters the straight traveling route Cs again from the adjacent field end point P3. By repeating such traveling, the traveling vehicle body 10 can cultivate the entire field evenly.

[0048] Next, the headland traveling route Ch will be specifically described based on Fig. 5.

[0049] When the straight traveling route Cs is finished being traveled, a headland traveling route Ch that turns around the inner circumference and exits the field is set. When entering the headland traveling route Ch, traveling is performed by the side detection sensor 621. It travels from the field end point P4 to the field end point R1 at the opposing position, and when turning at the field end point R1, the traveling control by the side detection sensor 621 ends. Then, after the turning ends, the traveling control by the side detection sensor 621 starts again, and it travels from the field end point R1 to the field end point R2. When entering the entrance / exit 14 of the field, the traveling control by the side detection sensor ends.

[0050] When the presence of the ridge is recognized by the detection range A2L of the ridge detection sensor 621, the automatic driving of the traveling vehicle body 10 is performed so as to travel along the ridge.

[0051] When the control is started, if the distance from the traveling vehicle body 10 to the ridge is set by the setter, the set value is read, and if not, the traveling process is executed based on within a specified range.

[0052] The ridge detection sensor 621 is a sensor that detects the presence of an object, such as an infrared sensor, an ultrasonic sensor, a millimeter-wave radar, etc., and is composed of a first ridge detection sensor 621A provided at the front of the traveling vehicle body and a second ridge detection sensor 621B provided at the rear of the traveling vehicle body. The sensor irradiates laterally and receives the reflection, and if there is a ridge on the side surface of the tractor, the distance to the ridge is detected.

[0053] When the traveling control is started, it is determined whether the detected value of the ridge detection sensor 621 is larger or smaller than within the specified range. Then, the difference between the detected value and within the specified range is calculated. The larger the difference, the larger the steering angles of the steering wheels 40L and 40R.

[0054] When the detected value of the first ridge detection sensor 621A detects a value smaller than within the specified range, it is determined that the front wheels are approaching the ridge. Also, when the detected value of the first ridge detection sensor 621A detects a value larger than within the specified range, it is determined that the front wheels are moving away from the ridge.

[0055] When the detected value of the second ridge detection sensor 621B detects a value smaller than within the specified range, it is determined that the rear wheels are approaching the ridge. Also, when the detected value of the second ridge detection sensor 621B detects a value larger than within the specified range, it is determined that the rear wheels are moving away from the ridge.

[0056] First, it is detected that the range within the detection value of the first side detection sensor 621A is larger or smaller than the specified range. And a control method when the detection value of the second side detection sensor 621B is within the specified range will be described.

[0057] When the detection value of the first side detection sensor 621A provided on the front side surface of the traveling vehicle body 10 detects a value larger than the specified range, and the detection value of the second side detection sensor 621B provided on the rear side surface of the traveling vehicle body 10 is within the specified range, the control unit 200 controls the steering wheels 40L and 40R to rotate in the side direction.

[0058] Then, as the difference between the detection value of the first side detection sensor 621A and the specified range becomes smaller, the rotation of the steering wheels 40L and 40R is returned, and the direction correction of the traveling vehicle body 10 is completed.

[0059] When the detection value of the first side detection sensor 621A detects a value smaller than the specified range, and the detection value of the second side detection sensor 621B is within the specified range, the control unit 200 controls the steering wheels 40L and 40R to rotate in the direction opposite to the side.

[0060] Then, as the difference between the detection value of the first side detection sensor 621A and the specified range becomes smaller, the rotation of the steering wheels 40L and 40R is returned, and the direction correction of the traveling vehicle body 10 is completed.

[0061] Next, it is detected that the detection value of the second side detection sensor 621B is larger or smaller than the specified range. And a control method when the detection value of the first side detection sensor is within the specified range will be described.

[0062] When the detection value of the second side detection sensor 621B detects a value larger than the specified range, and the range within the detection of the first side detection sensor 621A is within the specified range, the control unit 200 controls the steering wheels 40L and 40R to rotate in the direction opposite to the side.

[0063] As the difference between the detection value of the second ridge detection sensor 621B and the specified range decreases, the rotation of the steering wheels 40L and 40R is reversed, and the correction of the traveling vehicle body 10 is completed.

[0064] When the detection value of the second ridge detection sensor 621B detects a value smaller than the specified range, and further when the detection value of the first ridge detection sensor 621A is within the specified range, the control unit 200 controls the steering wheels 40L and 40R to rotate in the direction of the ridge.

[0065] As the difference between the detection value of the second ridge detection sensor 621B and the specified range decreases, the rotation of the steering wheels 40L and 40R is reversed, and the correction of the traveling vehicle body 10 is completed.

[0066] Next, the control method when the detection value of the first ridge detection sensor 621A is within the specified range and the detection value of the second ridge detection sensor 621B is also within the specified range will be described.

[0067] When the first ridge detection sensor 621A detects that the distance to the ridge is within the specified range and the second ridge detection sensor 621B detects that the distance to the ridge is within the specified range, the control unit 200 controls to maintain the positions of the steering wheels 40L and 40R so that the traveling vehicle body 10 travels straight along the ridge.

[0068] When the working machine 11 is mounted on the traveling vehicle body 10, the working machine recognition means 12 as the working machine recognition means of the working machine 11 is connected to the control unit 200 on the traveling vehicle body 10 side, and the body information such as the body width of the working machine 11 is registered in the control unit 200. The control unit 200 changes the detection range A2L of the ridge detection sensor 621 to the adjusted detection range A2L' based on the body width of the body information. That is, when the work vehicle equipped with the working machine 11 travels along the ridge, the mounted working machine is recognized, and the specified range is changed according to the working machine 11. Therefore, even when different-shaped working machines 11 are mounted, contact with the ridge can be avoided in autonomous driving and work can be performed efficiently.

[0069] In the land preparation work, when performing tillage work using a rotary tiller, the rotary tiller is connected to a tractor. The rotary tiller is provided with a chain case that protrudes to one side of the working machine.

[0070] By providing the ridge detection sensor 621 in the direction opposite to the chain case, it is possible to travel right up to the edge of the ridge, leaving the width of the chain case.

[0071] Also, the distance to the ridge can be arbitrarily changed by the driver using a setting device provided on the traveling vehicle body or a remote controller 201.

[0072] When traveling at the edge of the ridge, by keeping a specified distance between the ridge and the traveling vehicle body 10 with the sensor, it is possible to travel while maintaining a sufficient sense without the need for width adjustment by the driver's operation.

[0073] Furthermore, by maintaining a sufficient interval between the traveling vehicle body 10 and the ridge, it is possible to eliminate the risk of the traveling vehicle body 10 climbing onto the ridge and breaking the ridge with the wheels.

[0074] In the above embodiment, the ridge detection sensor 621 is configured on the left side of the traveling vehicle body 10, but it may be similarly configured on the right side of the traveling vehicle body 10. Also, as an automatic control method for the attitude of the traveling vehicle body 10 with respect to the ridge, the steering cylinders 330 are electronically controlled according to instructions from the control unit 200 to adjust the steering angles of the steering wheels 40L and 40R. However, it may also be configured to electronically control a motor attached to the steering wheel 16 according to instructions from the control unit 200 to adjust the steering angles of the steering wheels 40L and 40R.

Explanation of Reference Numerals

[0075] 10 Traveling vehicle body 11 Working machine 40L, 40R Front wheels (steering wheels) 50L, 50R Rear wheels 200 Control unit 621 Ridge detection sensor 621A First ridge detection sensor 621B Second Side Detection Sensor

Claims

1. A traveling vehicle body, a steering wheel attached to the traveling vehicle body, and a control unit for autonomously driving the traveling vehicle body, a first ridge detection sensor for detecting the distance from the front of the traveling vehicle body to the ridge is provided on the front side surface of the traveling vehicle body, a second ridge detection sensor for detecting the distance from the rear of the traveling vehicle body to the ridge is provided on the rear side surface of the traveling vehicle body, The control unit automatically steers so that the traveling vehicle body travels along the ridge based on the detection results of the first ridge detection sensor and the second ridge detection sensor. A work vehicle.

2. The control unit when the distance from the first ridge detection sensor to the ridge is within a specified range and the distance from the second ridge detection sensor to the ridge is also within the specified range, automatically steers to go straight. The work vehicle according to claim 1.

3. The control unit detects that the distance from the first ridge detection sensor to the ridge has deviated from the specified range, and when the distance from the second ridge detection sensor to the ridge is within the specified range, turns the steering wheel in the direction of the ridge and automatically steers so that the distance from the first ridge detection sensor to the ridge is within the specified range. The work vehicle according to claim 1.

4. The control unit when the distance from the first ridge detection sensor to the ridge is within the specified range and it is detected that the distance from the second ridge detection sensor to the ridge has deviated from the specified range, turns the steering wheel in the direction opposite to the ridge and automatically steers so that the distance from the second ridge detection sensor to the ridge is within the specified range. The work vehicle according to claim 1.

5. The control unit detects that the distance from the first ridge detection sensor to the ridge has become closer than the specified range, and when the distance from the second ridge detection sensor to the ridge is within the specified range, turns the steering wheel in the direction opposite to the ridge and automatically steers so that the distance from the first ridge detection sensor to the ridge is within the specified range. The work vehicle according to claim 1.

6. The control unit when the distance from the first ridge detection sensor to the ridge is within the specified range and it is detected that the distance from the second ridge detection sensor to the ridge has become closer than the specified range, turns the steering wheel in the direction of the ridge and automatically steers so that the distance from the second ridge detection sensor to the ridge is within the specified range. The work vehicle according to claim 1.

7. Obtains the width information of the work implement mounted on the traveling vehicle body, and sets a predetermined range of the distances from the first ridge detection sensor and the second ridge detection sensor to the ridge based on the width information. The work vehicle according to claims 2 to 6

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