JPH03148709A - Steering controller for automatic traveling working vehicle - Google Patents

Abstract

PURPOSE:To decrease the number of marker sensors and to reduce cost by burying markers under the ground and providing the marker sensor to be rotated while drawing an arc in a surface almost parallel to a working area. CONSTITUTION:In the traveling course of an automatic traveling working vehicle 1, long markers 5 are buried within the working area and in the automatic traveling working vehicle 1, a marker sensor 9 is provided to be rotated while drawing the arc in the surface almost parallel to the working area. When the automatic traveling lawn mower 1 is traveled by an electric motor 6 while rotating the magnetic sensor 9, the rotating magnetic sensor 9 detects the existence of a magnetic substance 5 and a potentiometer 10 detects how much angle the detected position is inclined to a traveling direction. An error detecting means detects position error and azimuth error from the traveling course for the turning center position of the automatic traveling lawn mower 1 and the steering of the automatic traveling lawn mower 1 is controlled in a direction so as to correct these errors. Thus, low-priced structure using one marker sensor can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a steering control device for an autonomous working vehicle.

2. Description of the Related Art Conventionally, an example of a self-driving working vehicle that travels automatically in an unmanned state is disclosed in Japanese Patent Application Laid-Open No. 135514/1983.

This self-driving work vehicle is equipped with multiple magnetic detection elements arranged in a direction perpendicular to the direction of travel of the self-driving work vehicle to detect the strength of the magnetic field of magnets placed at fixed points on the travel course. Based on the output from the element, the running position and running direction of the automatic traveling work vehicle when passing a fixed point are calculated, and steering control is performed to correct the running position and running direction based on the calculated values.

Problems to be Solved by the Invention However, in order to perform highly accurate steering control, it is necessary to increase the number of magnetic detection elements, which is extremely expensive.

Means for resolving the divisional labor issue: A long fiber body extending along the travel course of an automated driving work vehicle is intermittently buried underground within the work area, and a surface approximately parallel to the work area is installed. The automatic traveling work vehicle is provided with a marker sensor that detects the marker while rotating in an arc within the vehicle. An error detecting means for detecting a position error and a azimuth error of the automatic traveling work vehicle, and a steering control section for controlling the steering in a direction to correct the position error and azimuth error are provided.

When the automatic traveling work vehicle is driven while rotating the functional marker sensor, the marker sensor detects the marker at two points when passing above the marker.

Then, based on the detection results at these two points, the error detection means detects the positional error and azimuth error of the automated traveling work vehicle with respect to the traveling course, and the automated traveling work vehicle corrects these positional errors and azimuth errors. The steering is controlled by the steering control unit in the direction shown in FIG.

Example An embodiment of the present invention will be described based on the drawings.

A mower 4 is attached to the abdomen of an automatically traveling lawn mower 1, which is an automatically traveling work vehicle, and is located between a front wheel 2 and a rear wheel 3 so as to be movable up and down. On the other hand, underground in the work area where the self-driving lawn mower 1 is run, there is a long magnetic body 5 which is a long sign extending along the travel course where the self-driving lawn mower 1 is run. are buried intermittently.

Next, an electric motor 6 is attached to the front lower part of the self-driving lawn mower 1, and a lever 8 extending horizontally is attached to the lower end of a rotating shaft 7 of the electric motor 6 having an axis in the vertical direction. One end of the lever 8 is fixed, and a magnetic sensor 9, which is a marker sensor that detects the magnetism generated by the magnetic body 5, is attached to the other end of the lever 8. Furthermore, a potentiometer 10 for detecting the rotational position of the lever 8 is attached to the upper part of the electric motor 6.

Furthermore, the self-driving lawn mower l includes the magnetic sensor 9.
and the potentiometer lO, and
Error detection means 1 for detecting a positional error and an azimuth error of the automatically traveling lawnmower l with respect to the traveling course based on the detection result when the magnetic sensor 9 detects the magnetic body 5 at two points;
1, and a steering control section 13 that steers and controls the steering device 12 of the automatic mower I in a direction to correct these positional errors and azimuth errors.

In such a configuration, the electric motor 6 is driven to rotate the magnetic sensor 9 in a plane substantially parallel to the work area while the automatic lawn mower 1 is caused to travel along a predetermined travel course. The rotating magnetic sensor 9 detects the presence of the magnetic body 5 when passing above the magnetic body 5, and the potentiometer 10 determines how many degrees the detected position is tilted with respect to the traveling direction of the automatic mower 1. Detected. In addition, when the self-driving lawnmower l is moving straight along the driving course,
The detection angle by the potentiometer 10 is Oo or 18
It is 0°.

Next, when the self-driving lawnmower 1 travels off the predetermined travel course and the magnetic body 5 is detected at two points as shown in FIG. The tilt angle oll θ2 is detected by a potentiometer IO. Here, the turning center (X
@ v V* ) is the origin, the running direction is the Y axis, and the direction perpendicular to the running direction is the X axis, then the coordinates of the two detection positions by the magnetic sensor 5 are (X., y,), (X,,
yi) is determined by the error detection means 11. Note that the distance from the origin to the rotation center of the magnetic sensor 9 is L'', and the patent x characterized by the rotation radius of the magnetic sensor 9, =Qsin
θ1 7, = QcosO□+L x, = Asinθ1 yl Tomacos O, 10. Therefore, the predetermined travel course seen from the coordinate system of the self-driving lawnmower l is.

y = (ym-y*)/(xu-is) -x + (x
xym-xtym)/(is-is). Therefore, the turning center position (xa
, ys) from the travel course, and a positional error Δa'' and an azimuth error α'' are detected by the error detection means 11 as follows.

Δn = (Xg Fa -43Fg)/(Xs
-L) a = arc tan((xx -x*)
/ (yt - yt) ) and an autonomous lawnmower l
is steered by the steering control unit 13 in a direction that corrects these positional errors and azimuth errors, and travels on a predetermined running course.

Effects of the Invention As described above, the present invention embeds a long sign body extending along the travel course of an automated driving work vehicle in a work area,
A marker sensor that rotates in an arc in a plane approximately parallel to the work area is installed on the automatic driving work vehicle, and the marker sensor detects two points on the marker. Based on the detection results, the vehicle automatically travels along the driving course. By providing an error detection means for detecting the position error and azimuth error of the working vehicle, and by providing a steering control section for controlling the steering in a direction to correct these position errors and azimuth errors, one IIA identification body It is possible to have an inexpensive structure using sensors, and furthermore, it detects position errors and orientation errors based on the detection results of the rotating marker sensor.
This has effects such as being able to perform highly accurate steering control.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, and Fig. 1 is a block diagram showing a control system, Fig. 2 is a side view showing an autonomous lawn mower, and Fig. 3 is a detection state of position error and azimuth error. FIG. DESCRIPTION OF SYMBOLS 1... Automatic traveling work vehicle, 5... - Marker, 9... Marker sensor, 11... Error detection means, 13... Steering control unit 6-l Illf, 11 operator? -” l 11 (″)

Claims (1)

[Claims] A long sign that extends along the driving course of an automated driving work vehicle is intermittently buried underground within the work area, and rotates in an arc in a plane approximately parallel to the work area. A marker sensor for detecting the marker is provided in the automated driving vehicle, and the marker sensor detects two points on the marker and determines the position error and orientation of the autonomous vehicle with respect to the travel course based on the detection results of the marker sensor. 1. A steering control device for an automatic traveling work vehicle, comprising: error detection means for detecting errors; and a steering control section for controlling steering in a direction to correct these position errors and azimuth errors.