JPH0769222A - Direction changing method for moving vehicle and moving vehicle - Google Patents

Abstract

PURPOSE:To easily conduct direction change at a narrow spot in a moving vehicle which changes a direction at an end of a ridge in a cultivated field and after moving to an adjacent ridge travels to carry out agricultural work such as chemical spraying, by detecting a ridge end and the like by means of a position sensor to stop the vehicle, and turning each wheel by 90 degrees. CONSTITUTION:When a moving vehicle is between ridges A, owing to rotation of wheels 2 by hydraulic motors 16 the moving vehicle is advanced. When one side limit switch 23 touches the ridge A at a curve and the like of the ridge A, the direction of the wheel 2 is adjusted by a hydraulic cylinder 3. When an end of the ridge A is detected by a position sensor 5 of the moving vehicle, the vehicle is stopped after traveling by a specified distance and the respective wheels 2 are turned by 90 degrees by the hydraulic cylinder 3 to be in a state of facing sideways. The wheels 2 are rotated in this state to move transversely and when such advance of a specific distance as to be positioned between adjoining ridge A is detected based on output of a count rotary encoder 24 for detecting the number of rotations of the hydraulic motor 16, the vehicle is stopped and each wheel is turned by 90 degrees in the reverse direction to bring the vehicle into the original direction.

Description

Detailed Description of the Invention

[0001]

[Industrial applications]

The present invention relates to a method for changing the direction of a moving vehicle and a moving vehicle. More specifically, for example, by changing the direction at the end of a ridge in a field, the vehicle moves to an adjacent ridge and travels, sprays chemicals, etc. Related to the farm work.

[0003]

[Prior art]

[0004] In a mobile vehicle that performs agricultural work such as spraying chemicals while traveling between ridges, it is necessary to change the traveling direction at the end of the ridge.

In the case of a tractor capable of unmanned operation, which is equipped with a wheel whose direction is changed by a steering operation and a sensor for detecting the rotation angle of the wheel, the direction of the moving vehicle can be changed from the furrow to the headland. By turning out the steering wheel, turning the wheels to make a steady turn, and repeatedly turning back and forth as necessary, the direction of the entire vehicle body was turned to the next ridge to change the direction.

[0006]

[Problems to be Solved by the Invention]

However, the conventional technique has the following problems to be solved.

Since the conventional tractor turns the entire vehicle body to change the direction, a wide headland is required to change the direction.

Further, when turning, there are problems in turning distance, slip, control, etc., which will be described later, so that turning error tends to increase, and it is difficult to perform accurate direction change.

Regarding the turning distance, since it is a semicircle or a turning trajectory, the running distance required for turning is long, and the position detection error of the sensor becomes large due to the combination of angles and the like.

Regarding slip, in many cases, centrifugal force causes lateral slip (slip) in the outward direction.

In particular, since the tractor is driven by the differential gears to drive the wheels, the load on either the left or right wheel is different, and if it slips, the wheel tries to turn faster, so that the turning radius is the road surface condition. Is not constant due to.

Regarding the control, since the direction of the vehicle is grasped in real time with respect to the steering angle and the angle is corrected, it is difficult to perform control for accurate correction.

Regarding the turning error, it is necessary to detect the azimuth and the angle to detect the position. However, the accuracy of detecting the angle is lower than that of detecting the distance, and the error with respect to the slip or the direction of the vehicle is reduced. Correction is required.

For example, the beam angle of the photoelectric sensor is about 5 °, and that value becomes an error. When this beam angle is 0 °, detection is difficult. The geomagnetic sensor is unstable in some regions and forms a dip angle of less than 50 ° with the horizontal plane, so correction is necessary.

For the above-mentioned reason, conventionally, even if the turning angle or the like is sensed by a sensor or the like, an accurate turning is very difficult because a turning error occurs, and in reality, unmanned operation of a moving vehicle is impossible. Met.

In order to enable a direction change in a headland as narrow as possible, there is a vehicle that can turn on the spot with the center of the main body of the moving vehicle as a rotation axis.

This is provided with a steering motor, a reduction gear, a light receiving sensor, and a drive motor provided at the front and rear parts, and stops when the light receiving sensor on the left side of the vehicle detects infrared rays reflected from the reflector. The turning mechanism operates and turns in the clockwise direction on the spot with the center of the main body as the axis of rotation.

In this case, since the rear sensor senses the reflected light during the turning, the drive motor is stopped at the turning of about 90 °, and the vehicle moves in the ridge direction toward the ridge.

At this time, the deviation of the direction of the vehicle is corrected by making a slope on the ridge surface and utilizing the twist angle of the wheel raised to the ridge to slide it into the ridge to correct the start.

[0021] However, in such an on-the-spot turn, since centrifugal force acts at the time of turning, an error in azimuth or position is likely to occur due to slip or the like, and it is difficult to perform an accurate direction change. In addition to being unable to be unmanned, it also had the following problems.

That is, it is necessary to install a sign at the main part of the land.

When the vehicle moves to the ridge without turning 90 °, the ridge surface is inclined by 30 to 50 ° to correct the steering. However, depending on the weight of the vehicle,
I could not crush the ridges or correct the steering,
In some cases, the body tilts.

Therefore, there has been a demand for a means which can change the direction even in a narrow headland, and can change the direction accurately, and in fact, enables an unmanned operation of a mobile vehicle.

[0025]

[Means for Solving the Problems]

Means for solving the problems of the present invention are as follows.

First, a moving vehicle that travels by wheels is
First, after moving to the front side and stopping by detecting the stop position by the sensor, each wheel rotates 90 ° about the axis orthogonal to the contact point between the wheel and the ground as the rotation axis, and the direction of the wheel changes to the front of the moving vehicle. After turning sideways toward the side, it advances a certain distance in the horizontal direction and stops, and again, each wheel rotates 90 ° about the axis orthogonal to the contact point between the wheel and the ground as the rotation axis, and the direction of the wheel is changed. A method for changing the direction of a moving vehicle, in which after the wheel is returned to its original position, the wheels are rotated in the opposite direction to the direction in which the wheels are moving to the front side and travel toward the rear side to change the direction of the moving vehicle.

Secondly, a main body, a wheel for supporting the main body, a detecting means for detecting the rotation angle of the direction of the wheel, and a position sensor for detecting the stop position are provided, and each wheel has a wheel and a ground surface. A mobile vehicle that is rotatably mounted so as to be laterally facing the front side, with an axis perpendicular to the contact point of as the axis of rotation.

Here, the detecting means for detecting the rotation angle of the direction of the wheel may be any means capable of detecting that the direction of the wheel has become sideways, for example, for changing the direction of the wheel. In addition to the potential meter attached to the hydraulic cylinder, a position detection object that moves according to the direction of the wheel and a sensor that detects the position detection object may be used.

[0030]

[Action]

The moving vehicle advances toward the front side as the wheels rotate to the front side, and stops when the stop position is detected by the position sensor for detecting the ridge end or the like.

At the stop position, each wheel rotates 90 ° about the axis orthogonal to the contact point between the wheel and the ground, and turns sideways toward the front side.

Then, the main body is directed toward the front side, moves in the lateral direction, advances a fixed distance so as to be located between the adjacent ridges, and then stops.

After stopping, each wheel again rotates 90 ° about the axis orthogonal to the contact point between the wheel and the ground as the rotation axis, and after returning the direction of the wheel to the original direction, when the wheel advances to the front side. The direction of the moving vehicle is changed by rotating in the opposite direction and traveling toward the rear side.

When moving toward the rear surface side, the position sensor for detecting the ridge end or the like stops when the stop position is detected, and by performing the same operation as the above operation, the direction is changed and the next operation is performed again. Proceed to the front side through the ridge and repeat the above operation.

[0036]

【Example】

An embodiment of the mobile vehicle according to the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic perspective view of a main part of a mobile vehicle according to the present invention, and FIG. 2 is a schematic side view of the entire mobile vehicle according to the present invention.
FIG. 3 is an explanatory view of an operation of the moving vehicle according to the present invention during movement between the ridges, and FIG. 4 is an explanatory view of an operation of the moving vehicle according to the present invention at the time of changing the direction.

As shown in FIG. 1 or 2, the mobile vehicle of the present invention includes a main body 1, a wheel 2 supporting the main body 1, a hydraulic cylinder 3 and a hydraulic cylinder 3 for detecting the rotation angle of the direction of the wheel 2. 3, and a position sensor 5 that senses the stop position by sensing the end of the ridge A, and a potentiometer 4 attached to the end of the ridge 3.

The main body 1 includes an engine 6 as shown in FIG.
A hydraulic pump 7, a control unit 8 that controls the operation of electromagnetic valves (not shown) of each unit provided in the hydraulic system, and a battery 9 are provided on the first substrate 10.

Although not shown in detail, the hydraulic pump 7, solenoid valve (not shown), hydraulic motor 1 described later.
6, the power is transmitted by the hydraulic cylinder 3.

The first board 10 is connected to the second board 12 by a rolling joint 11, and two wheels 2 are attached to each of the first board 10 and the second board 12.

In the following description, the wheel 2 side on the second substrate 12 side is the front side, and the wheel 2 side on the first substrate 10 side is the rear side.

Here, by connecting the front wheel 2 to the rear wheel 2 via the rolling joint 11, one wheel 2 floats while traveling on a field which is generally an uneven terrain. Also, the wheel 2 on the opposite side becomes a pendulum with the rolling joint 11 as a fulcrum, and contacts the wheel 2
It is possible to prevent uneven rotation of the whole.

As shown in FIG. 1, each wheel 2 is attached to a downward U-shaped frame 13 by an axle 14.

The U-shaped frame 13 is connected to a rotary shaft 15 having a power transmission shaft (not shown) orthogonal to the contact point between the wheel 2 and the ground inside.

On the upper end side of the power transmission shaft, the hydraulic motor 16
Is attached.

The power transmission shaft is rotated by the hydraulic motor 16.

On the outer peripheral surface of the rotating shaft 15 of the wheel, a pair of direction detecting plates 17 and a sprocket 18 for changing the direction of the axle 14 are attached.

In FIG. 1, numeral 19 indicates the direction detecting plate 1.
7 shows a directional sensor for sensing the position of 7.

The directional sensor 19 is, as shown in FIG.
Two pieces are attached to each direction detection plate 17.

The direction detecting plate 17 and the direction sensor 19 described above.
Is attached to one wheel 2 on the front surface side and the rear surface side.

A worm gear 20 is attached to the U-shaped frame 13 side of the power transmission shaft.
The rotational force of is transmitted to the axle 14 by the chain 21 so that each wheel 2 rotates.

On the sprocket 18 attached to the rotary shaft 15, the chain 2 operated by the hydraulic cylinder 3 is attached.
2 is hung, and the rotation of the rotating shaft 15 moves in association with the sprocket 18 by the operation of the chain 22 and the direction of the wheel 2 changes.

Here, as the rotary shaft 15 is rotated 90 ° by the operation of the hydraulic cylinder 3, the direction of the wheel 2 becomes horizontal with respect to the front side.

In FIG. 1, numeral 23 indicates a limit switch for detecting the ridge A.

Further, in FIG. 1, numeral 24 indicates the hydraulic motor 1.
6 shows a rotary encoder for measuring the movement of No. 6.

Next, the operation of the above-mentioned moving vehicle will be described with reference to FIG. 3 or 4.

In FIG. 4, in order to explain the operation,
The moving vehicles are shown in simplified form with numbers.

First, the moving vehicle is installed between the ridges A and the switch is turned on.

Then, the moving vehicle advances toward the front side by rotating the wheels 2 to the front side by the hydraulic motor 16, and performs agricultural work such as spraying pesticides while moving between the ridges A (in FIG. 4, Number 1, number 2).

During the movement between the ridges A, neither of the limit switches 23 is in contact with the ridges A, as shown in FIG. 3 (a).

In this state, each of the upper direction sensors 19 is
Senses the lower end of the corresponding direction detection plate 17.

When it is necessary to correct the traveling direction due to a ridge or a bend of a crop, one limit switch 23 comes into contact with the ridge A as shown in FIG.
A signal is output to the hydraulic cylinder 3 so that the direction of the wheel 2 and the two wheels of the front wheel or the rear wheel with respect to the traveling direction are separated from the ridge.

Then, in response to the signal, the hydraulic cylinder 3 first adjusts the direction of the wheel 2 so as to move away from the ridge A.

Then, the limit switch 2 in contact with
3 is away from the ridge A, and one direction sensor 19 on the lower side
However, when the end of the corresponding direction detection plate 17 is sensed, it is assumed that the correction of the direction of the wheel 2 is completed, and the direction of the wheel 2 is
Finally, the state shown in FIG. 3C is adjusted.

In this way, in the ridge, the steering is corrected within a certain angle, and the steering angle for automatic steering can be reduced, so that the load on the engine output is reduced.

When the position sensor 5 of the moving vehicle detects the end of the ridge A, the moving vehicle further advances by a distance to completely enter the headland and then stops (number 3 and number 4 in FIG. 4).

At the stop position, the hydraulic cylinder 3 of the moving vehicle
However, it operates until the value of the potentiometer 4 detects an initial setting value corresponding to a rotation angle of 90 °.

Then, each wheel 2 of the moving vehicle has a rotary shaft 15
It rotates 90 degrees about the center and turns sideways toward the front side (number 5 in FIG. 4).

Then, with the main body 1 still facing the front side,
The wheels 2 are rotated by the operation of the hydraulic motor 16 to move in the lateral direction, and the rotary encoder 24 causes the hydraulic motor 1 to move.
When the number of rotations of 6 is counted and it is detected that the vehicle has traveled a certain distance so as to be located between the adjacent ridges A, the hydraulic motor 16 is stopped and the main body 1 is also stopped on the spot (number in FIG. 4). 6).

After the stop, the hydraulic cylinder 3 operates again to return the position of the wheel 2 to the original position, whereby each wheel 2 rotates 90 ° to the opposite side about the rotation shaft 15 and returns to the original position. Return to the direction (number 7 in FIG. 4).

Next, by operating a hydraulic traveling solenoid valve (not shown) in the reverse direction, the wheel 1 rotates in the direction opposite to the direction in which the wheel 2 advances to the front side, and the main body 1 moves toward the rear side. Then, the direction change of the moving vehicle is completed (number 8 in FIG. 4).

Here, the distance traveled between adjacent ridges A is
When it is not accurate due to the influence of slip or the like, when the moving vehicle runs toward the rear side, one limit switch 23 comes into contact with the ridge A, and the direction of the wheel 2 is adjusted as described above, and the track of the moving vehicle is adjusted. Corrections are made.

When the position sensor 5 detects the end of the ridge A toward the rear surface side, the direction is changed by performing the same operation as described above, and the ridge further advances to the next ridge.

By repeating the above-mentioned running between the ridges and the direction change at the ridge ends, the agricultural work in a predetermined range is performed.

Here, predetermined data and procedure such as the number of times of direction change, the direction of the first direction change, the distance between the ridges, etc. are input to the control unit 8 in advance, and these are inputted to the potentiometer 4, the rotary encoder 24, and the like. By comparing the information from the position sensor 5 and sequentially executing it, unmanned operation by automatic control becomes possible.

[0078]

【The invention's effect】

The traveling vehicle according to the present invention has a short traveling distance because the wheels are bent at a right angle, and it does not require detection of an arcuate position. Therefore, it can be accurately turned, and new equipment such as signs and cables is not required.

Therefore, according to the present invention, the direction can be changed even in a narrow headland, and moreover, the direction can be changed accurately, and the unmanned operation of the moving vehicle can be actually realized.

[Brief description of drawings]

FIG. 1 is a schematic perspective view of a main part of a mobile vehicle according to the present invention.

FIG. 2 is a schematic side view of an entire mobile vehicle according to the present invention.

FIG. 3 is an explanatory diagram of an operation during movement of the vehicle according to the present invention between the ridges.

FIG. 4 is an explanatory diagram of an operation at the time of changing the direction of the moving vehicle according to the present invention.

[Explanation of symbols]

 A ridge 1 main body 2 wheel 3 hydraulic cylinder 4 potentiometer 5 position sensor 6 engine 7 hydraulic pump 8 control unit 9 battery 10 first substrate 11 rolling joint 12 second substrate 13 U-shaped frame 14 axle 15 rotating shaft 16 hydraulic motor 17 direction Detection plate 18 Sprocket 19 Direction sensor 20 Worm gear 21 Chain 22 Chain 23 Limit switch 24 Rotary encoder

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display location G05D 1/02 N 9323-3H // A01C 11/02 320 Z 8602-2B

Claims (2)

[Claims] 1. A mobile vehicle traveling by wheels is
After advancing to the front side and stopping by detecting the stop position by the sensor, each wheel rotates 90 ° around the axis orthogonal to the contact point of the wheel and the ground as the rotation axis, and the direction of the wheel is set to the front side of the moving vehicle. After turning sideways toward the side, it advances a certain distance in the horizontal direction and stops, and again, each wheel rotates 90 ° around the axis orthogonal to the contact point between the wheel and the ground as the rotation axis, and based on the direction of the wheel. After returning, the method of changing the direction of the moving vehicle, in which the direction of the moving vehicle is changed by rotating in the direction opposite to the direction in which the wheels move to the front side and traveling toward the rear side. 2. A main body, a wheel supporting the main body, a detection means for detecting a rotation angle of a direction of the wheel, and a position sensor for detecting a stop position, each wheel being in contact with the wheel and the ground. With the axis orthogonal to the location as the axis of rotation, it is rotatably attached so that it faces sideways toward the front side.
Moving car.