JPH021B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an automatic traveling work vehicle, and more particularly, to a self-driving work vehicle, and more specifically, a vehicle that performs ground work within a work area while repeatedly traveling from one end of the work site to the other end while automatically changing direction in a reciprocating process. The present invention relates to an automatic traveling work vehicle equipped with a tracing sensor that detects the boundary in order to automatically travel along the boundary between a treated work site and an untreated work site in each stroke.

Conventionally, in this type of automatic driving work vehicle, the sensor detects the boundary in order to automatically travel along the boundary based on the boundary detection result between the treated work area and the untreated work area in each process by the above-mentioned scanning sensor. When a deviation from the boundary is detected, steering control is performed to automatically correct the traveling direction so that the vehicle body aligns with the boundary by performing a steering operation in the opposite direction to the direction of the deviation.

However, the above-mentioned conventional steering control is controlled to sequentially follow the boundary between the newly created treated work area and the untreated work area, which is the next process, every time the vehicle travels one stroke. It had the following drawbacks.

That is, each time the reciprocating process is repeated, the nonlinearity of the boundary is accumulated, and as a result, the linearity gradually deteriorates, resulting in a disadvantage that the aesthetic appearance of the work trace becomes poor.

The present invention has been made in view of the above-mentioned circumstances, and an object of the present invention is to provide an automatically traveling work vehicle equipped with a control means that prevents accumulation of non-linearity of the boundary to be followed.

In order to achieve the above object, an automatic traveling work vehicle according to the present invention is provided with an orientation sensor that detects a deviation in the traveling direction from a reference orientation, and for one stroke after the completion of a predetermined number of strokes of the reciprocating process, the automatic traveling work vehicle according to the present invention The present invention is characterized in that it is provided with means for correcting the traveling direction of the vehicle body 1 based on the comparison result between the direction detected by the sensor and the reference direction.

Due to the above features, the following excellent effects have been achieved.

That is, by performing direction control that automatically corrects the running direction in the reference azimuth direction instead of copying control every predetermined stroke, the non-linearity of the boundary and the accumulation of errors in directionality can be eliminated. This resulted in a much better aesthetic appearance after the work was completed. Embodiments of the present invention will be described below with reference to the drawings.

As shown in FIG. 1, a lawn mowing device 4 is suspended between the front and rear wheels 2, 3 of the vehicle body 1 so as to be movable up and down, and a lawn area serving as an untreated work area is placed in front of the vehicle body 1, which is the boundary between the running areas. Tracing sensors A, A having the configuration described later are installed on the front left and right sides of the vehicle body 1, respectively, to determine the boundary L between the unmoved land B and the mowed land C, which is the treated work area. It is configured as a lawn mowing vehicle.

Furthermore, the vehicle body 1 has a direction (azimuth) of the vehicle body 1.
In order to detect this, an azimuth sensor 5 is mounted which detects the azimuth θ by detecting the geomagnetic strength.

The front wheels 2, 2 serve as steering wheels and are automatically moved by a predetermined amount in the left and right directions by the control device 6 based on the boundary L detection result by the copying sensor θ and the orientation θ detection result by the orientation sensor 5. It is configured to be operated by steering.

The copying sensor A includes three optical sensors S1, which are arranged at predetermined intervals in the left-right direction of the vehicle body 1;
It is composed of S2 and S3.

As shown in FIG. 2, the optical sensors S1, S2, and S3 are provided with a U-shaped sensor frame 7,
7 is fixed to a sensor mounting frame 8 provided on the lawn mower 4, and a light emitting element P1 and a light receiving element P are respectively mounted on the inner facing surface of the sensor frame 7.
2 are provided as a pair, and by sensing the presence or absence of grass that is introduced as the vehicle body 1 travels between the light emitting element P1 and the light receiving element P2, it is possible to distinguish between the unmowed area B and the already mowed area. It is configured to determine the boundary L with C.

Usually, the two adjacently arranged
The boundary L is determined by two optical sensors S1 and S2, and the vehicle body 1 is
The boundary L is determined by the optical sensor S3 and the outermost optical sensor S1, which are arranged inwardly and separated from each other.

In addition, as sensor A, optical sensors S1 and S
2. The sensor is not limited to one using S3, and may be constructed from any type of sensor, including contact type and non-contact type.

A control system that automatically operates the steering wheel based on the boundary L detection result and the orientation θ detection result by the scanning sensors A, A and the orientation sensor 5 will be described below.

As shown in FIG. 3, the control system includes a control device 6 whose main part is composed of a microcomputer, and signals from three optical sensors S1, S2, S3 constituting the scanning sensor A and an orientation sensor. an electromagnetic valve 10 that operates a hydraulic cylinder 9 as an actuator in order to steer the front wheels 2, 2 by a predetermined amount in the left-right direction based on these signals;
It is configured to calculate and output a control signal for driving the .

Normally, based on the combination of the detection results of the unmoved area B and the mowed area C of the adjacently arranged optical sensors S1 and S2, the optical sensor S1 located outside the vehicle body 1 detects the mowed area C. The hydraulic cylinder 9 is operated at a predetermined speed while mowing the lawn so that the inner optical sensor S2 detects the unmowed area B, that is, the area is along the boundary L. It travels automatically by repeatedly changing direction at the end of its travel.

On the other hand, the number of strokes is measured by counting the number of times N of the direction changes, and each time the number N reaches a predetermined number No, in the next stroke, the adjacent optical sensors S1 and S2 are changed. In order to steer the front wheels 2, 2 based on the combination of the detection results of the unmoved area B and the mowed area C by the optical sensor S1 disposed on the outermost side and the third optical sensor S3 disposed on the innermost side. , when the dead zone width d of the boundary L detection state is made wider than normal, and the optical sensor S1 is in a state where the mowed land C is detected and the optical sensor S3 is in the state where the unmown land B is detected, The detected orientation θ by the orientation sensor 5 is compared with the reference orientation θo, and the detected orientation θ and the reference orientation θo are determined.
By using steering control based on the detected orientation θ, the straightness of the vehicle body 1 in the running direction and the parallelism of each stroke are determined for each predetermined stroke No. so that It will be automatically corrected.

In FIG. 3, R is a potentiometer for detecting the actual steering operation amount of the front wheels 2, 2 and feeding it back to the control device 6, and FIG. 4 shows the operation of the control device 6 explained above. This is a flowchart.

Further, the value of the reference orientation θo may be a value artificially set in advance, an average orientation calculated by sampling the orientations θ in the first stroke, or
Among the directions, etc. calculated by outer circumferential teaching, which runs around the outer circumference of the round trip in order to set the working range of the lawn and detect various control parameters,
Any orientation may be used.

Furthermore, the optical sensor S3 is not provided for each of the left and right scanning sensors A, but for example, one is provided at the center of the vehicle body 1 and the left and right scanning sensors A, A are provided.
It may be configured to be shared by multiple users.

[Brief explanation of drawings]

The drawings show an embodiment of the automatic driving vehicle according to the present invention, in which FIG. 1 is an overall plan view of the lawn mowing vehicle, FIG. 2 is a front view of the main parts of the scanning sensor, and FIG. 3 is a block diagram of the control system. FIG. 4 is a flowchart showing the operation of the control device. 1... Vehicle body, 5... Orientation sensor, A... Copying sensor, B... Untreated work area, C... Treated work area, L... Boundary, θo... Reference orientation, θ... Detection orientation, No...predetermined number of strokes, d...dead band width.

Claims (1)

[Claims] 1. The reciprocating process is repeated while automatically changing direction, and the treated work area is moved in each process so that ground work within the work area is performed while going from one end of the work area to the other end. In order to automatically travel along the boundary L between C and the untreated work area B, the automatic traveling work vehicle is equipped with tracing sensors A and A that detect the boundary, and detects a deviation in the traveling direction from the reference direction θo. A direction sensor 5 is provided, and for one stroke after the completion of a predetermined number of strokes in the reciprocating process, the traveling direction of the vehicle body 1 is corrected based on the comparison result between the direction θ detected by the direction sensor 5 and the reference direction θo. An automatic driving work vehicle characterized by being provided with a means for doing so. 2 One stroke after the completion of the predetermined number of strokes No.
In order to correct the traveling direction based on the direction θ detection result by the direction sensor 5, the dead zone width d for boundary detection of the scanning sensor A is set wider than usual, and when the scanning sensor A is in the boundary detection state. The automatic traveling work vehicle according to claim 1, characterized in that the vehicle is configured so that the direction of travel can only be corrected by the orientation sensor 5.