JPH012503A - Self-driving work vehicle - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an automatic traveling work vehicle, and more particularly, in order to automatically travel along a predetermined boundary of a traveling area, the present invention has a tracing sensor for detecting the boundary, and a front wheel and a rear wheel. The present invention relates to an automatic driving work vehicle in which both wheels can be operated by steering.

Conventionally, this type of self-driving work vehicle has been equipped with a sensor that detects the boundary of the driving area as a means of automatically driving on a predetermined driving course, and the driving direction is automatically corrected based on the boundary detection result of this sensor. Steering control is being performed. For example, rather than steering only the front wheels, a work vehicle that allows both the front and rear wheels to be steered allows for more precise corrections in the running direction, as well as the ability to move the vehicle in parallel without changing the direction of the vehicle. Therefore, as mentioned above, it has been considered to adopt a configuration in which both the front and rear wheels can be steered.

However, even with an autonomous work vehicle having the above configuration, the direction of the vehicle body may change naturally due to wheel slipping, etc., and as a result, there is an inconvenience that the ability to follow the boundaries of the driving area deteriorates. It was.

The present invention has been made in view of the above-mentioned circumstances, and its purpose is to provide an automatically traveling work vehicle equipped with means for automatically correcting the direction of the vehicle body in order to automatically travel along a predetermined boundary of a traveling area. It's about doing.

To achieve the above object, an automatic driving work vehicle according to the present invention is provided with a direction sensor that detects the running direction of the vehicle body, and based on the comparison result between the detected running direction by the direction sensor and a reference direction, the steering of the front wheels is performed. The present invention is characterized in that it includes means for automatically offsetting the manipulated variable by a predetermined amount.

Because of the above characteristics, the following excellent effects have been achieved.

If the direction of the vehicle deviates from the reference direction, the amount of steering operation for the front wheels is automatically offset by a predetermined amount, so when the direction of travel deviates from the boundary, the amount of steering operation for the front and rear wheels is different. When returning to the boundary, the direction of the vehicle can be corrected at the same time, resulting in extremely good straight-line tracking to the boundary.

Embodiments of the present invention will be described below with reference to the drawings.

As shown in Figure 1, the vehicle body (1) has front wheels (2), (2) and rear wheels (2) that can be independently steered.
3), (3) are provided, and this front wheel (2), (2)
and rear wheels (3), a lawn mower (4) with a disk-shaped cutting blade installed in the middle part of the lawn mower (4) is vertically movably suspended, and a scanning sensor (A) and a vehicle body (1) configured as described below are suspended.
) is provided with an orientation sensor (5) for detecting the traveling direction of the lawn mowing vehicle as an automatically traveling vehicle.

Then, the detection result of the predetermined boundary of the driving area by the tracing sensor (8) and the vehicle body (1) by the direction sensor (5) are detected.
) Based on the running direction detection result of the front wheels (2), (
2) and the rear wheels (3) and (3) are operated simultaneously to automatically drive the vehicle along a predetermined boundary and in a predetermined direction.

The sensor (A) is composed of two optical sensors (s+) and (S2) arranged in parallel in the left-right direction of the vehicle body (1). This optical sensor - (St), (St)
As shown in FIG. ) are provided with light emitting elements (P
1) and a light receiving element (P2) are provided as a pair, and between this light emitting element (P,) and the light receiving element (P2),
) is configured to determine the boundary (L) between the unmowed area (B) and the mowed area (C) by sensing the presence or absence of grass introduced as the vehicle moves.

Note that the sensor (8) is an optical sensor (St).

It is not limited to the one using (S2), and may be constructed from any type of sensor, whether contact type or non-contact type.

On the other hand, the orientation sensor (5) is constituted by a sensor capable of detecting the orientation of the vehicle body (1) at the measurement point, such as a geomagnetic sensor.

Hereinafter, a control system that performs a steering operation based on the detection results of the tracing sensor (^) and the direction sensor (5) having the above-mentioned configuration will be described.

As shown in FIG. 3, the control system includes signals from the tracing sensor (A) and the direction sensor (5) that are manually input to a control device (8) whose main part is composed of a microcomputer. Each of these sensors (^), (5
) based on the boundary detection result and the direction (ψ) detection result, the front wheel (2).

(2) and a rear wheel (3), a hydraulic cylinder (9) as an actuator for steering operation of (3),
Electromagnetic valve (11), (1) that operates (10)
2) is configured to calculate and output a control signal for driving.

That is, normally, the uncut land (B) is detected by the tracing sensor (A).
) and the mown field (C), the hydraulic cylinders (9), (10) are operated to drive the front wheels (2), (2) and the rear wheels (3), ( 3) in the same direction at a predetermined steering angle (S) to move the vehicle body (1) in parallel.
The vehicle performs steering control (copying control) so that the vehicle travels along the boundary (L).

On the other hand, the direction (ψ) which is the traveling direction of the vehicle body (1) detected by the direction sensor (5) is the reference direction (ψ) which is set in advance.
0) by more than a predetermined value (K),
Steering control by the copying sensor (^) is interrupted until this deviation is within a predetermined value (K), and the predetermined steering angle (S) of the front wheels (2) and (2) side is adjusted to the reference direction (ψ0). A predetermined angle (
Kψ) offset and perform steering control to correct the direction of the vehicle body (1).

In addition, (R1) and (R1) in Fig. 3 are the front wheels (2), respectively.
, (2) and the rear wheels (3), is a potentiometer for detecting the actual steering angle (θ) of (3) and feeding it back to the control device (8). It is a flowchart showing the operation of the explained control device (8).

Also, (S゛) in Fig. 4 is the offset front wheel (2).
, (2) is the target steering angle, and (α) is the misjudgment difference.

By the way, the reference direction (ψ0) may be set by manually inputting this reference direction (ψ0) into the control device (8) in advance. It is also possible to use the orientation detected during work such as perimeter teaching, which sets the work range and simultaneously collects control parameters for automatically performing subsequent work.

Furthermore, the present invention can be used not only as a means for correcting steering operation using a scanning sensor as shown in this embodiment, but also for correcting steering operation when automatically driving around an obstacle or changing direction. It can be used as a correction means.

[Brief explanation of the drawing]

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 copying sensor, and FIG. 3 is a block diagram of the control system. And Figure 4 is (a). (1:11 is a flowchart showing the operation of the control device. (1)...Vehicle body, (2)...Front wheels, (
3)... Rear wheel, (5)... Force position sensor, (A)... Great sensor, (ψ)...
...Detection direction, (ψ0) ...Reference direction, (S゛) ...Steering operation amount, (Kψ) - Old ...
Predetermined amount.

Claims (1)

[Claims] In order to automatically travel along a predetermined boundary of a running area, it has a tracing sensor (A) that detects the boundary, and both front wheels (2), (2) and rear wheels (3), (3). This is an automatic driving work vehicle that is configured to be able to operate the steering wheel, and is equipped with a direction sensor (1) that detects the running direction of the vehicle body (1).
5), and based on the comparison result between the driving direction (ψ) detected by this direction sensor (5) and the reference direction (ψ_0),
Steering operation amount (S') of the front wheels (2), (2)
An automatic traveling work vehicle characterized by being provided with means for automatically offsetting by a predetermined amount (Kψ).