JPS6379005A - Position calculator for unmanned transport truck - Google Patents

Abstract

PURPOSE:To enable the detection of the direction and position of an unmanned transport truck without use of a marker provided on a running road surface or the like, by detecting a fade-out position and a passage end position on an observing screen to calculate the direction of the unmanned transport truck and the distance from the passage end thereof. CONSTITUTION:An image taken by a photographing section (video camera) 101 is fed to a vanishing point detecting section 103 after being stored into an image memory 102 to calculate a fade-out position (X, Y). Then, with a direction calculating section 104, the direction theta of an unmanned transport truck is calculated using coordinates of the vanishing point position, the number of pixels of an observation image, pixel size thereof and the like. On the other hand, with a passage end detecting section 105, the position of a passage end is calculated on the basis of the contents of a memory A 102 to be stored into an image memory 106. Then, with a position calculating section 107, the position of the unmanned transport truck (distance from right and left passage ends) is calculated from the vanishing position (X, Y) and the passage end position stored in the memory 106. Thus, the direction theta and position information can be used to control the running so that the unmanned transport truck continues to run along a fixed length of line from the passage end.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a position calculation device that calculates the direction and position of an automatic guided vehicle in order to control the travel of the automatic guided vehicle.

(Prior art) Conventionally, automatic guided vehicles have been used to transport parts and materials within factories, but the direction and position calculation device that calculates the traveling direction and current position of this type of automatic guided vehicle has a This is a system in which line-shaped or spot-shaped marks (markers) that can be sensed are installed on the wall, and those marks are sensed by a light-receiving element attached to the automatic guided vehicle to calculate the direction and position of the own vehicle. (for example, Japanese Patent Application Laid-Open No. 17306/1983).

With conventional direction position calculation devices like this, markers have to be installed on the ground or walls, so when changing the factory layout or expanding the factory, the markers must be reinstalled. Furthermore, maintenance and management to prevent dirt is difficult.

(Objective and Structure of the Invention) The present invention has been made in view of the above points, and an object of the present invention is to realize a travel control system for an automatic guided vehicle that can cope with layout changes or additions without reinstalling markers. To achieve this purpose, we detect the vanishing point position of the observation screen and the path end position from the observation screen, and determine the direction of the automated guided vehicle from the detected vanishing point position and the direction of the unmanned guided vehicle from the detected path end position. The system is configured to calculate the distance from the end of the path of the transport vehicle.

(Example) Hereinafter, the present invention will be explained based on the drawings.

FIG. 1 is a block diagram of an embodiment of a directional position calculation device according to the present invention.

First, to explain the configuration, this device includes an imaging section 101, l!
An image memory AlO2 that stores shadowed images, a vanishing point detection unit 103 that detects the vanishing point position of the observed image from the contents of the image memory AlO2, and a direction calculation unit that calculates the direction of the automatic guided vehicle from the detected vanishing point position. 104, image memory AlO
A path end detection unit 105 detects the path end position in the observation image from the contents of 2, an image memory B 106 stores the detected path end position, and a path end detection unit 105 detects the path end position in the observation image. It is composed of a position calculation unit 107 that calculates a position. Note that all of the above-mentioned units 101 to 107 are installed on the platform of the automatic guided vehicle.

Next, relax your movements.

The image captured from the imaging unit 101 is stored in the image memory AlO
2 and then sent to the vanishing point detection unit 103, where the vanishing point position (X, Y) is calculated. Conventionally known methods are used to calculate the vanishing point position, such as the method proposed by Kender using Hough transform and the method proposed by Ohta et al. Use methods. Using the vanishing point position thus calculated, the direction θ of the automatic guided vehicle is calculated in the direction calculation unit 104.

That is, in Fig. 2 (a), Dl is the traveling direction of the automatic guided vehicle, D2 is the direction of the vanishing point, and as shown in Fig. 2 (b), the observed image is N pixels x M pixels, and the pixel size is pXq, vanishing point. If the coordinates of the point position are (X, Y) and the focal length of the lens when the imaging unit 101 is a video camera is f, then the direction of movement of the automatic guided vehicle (the angle formed with the vanishing point direction) θ is as follows. Meanwhile, the path end detection section 105 calculates the position of the path end based on the contents of the image memory AlO2.

3 and 4 diagrammatically show the video camera constituting the imaging unit 101 as viewed from the side and from above. As shown in FIG. Let δ be the vertical angle of view of the lens and ω, then P−
The distance d between the bottom of the floor surface to which the P' line is closest and the focal point M of the lens is as follows.

On the other hand, as shown in FIG. 4, if the horizontal angle of view of the camera 101 is considered, the coordinates of the path end positions Δ and B can be calculated. The path end position calculated in this way is stored in the image memory 8106 in the form shown in FIG. 5, for example.

The position calculating unit 107 calculates the position of the automatic guided vehicle (distance from the end of the path) from the vanishing point position calculated by the vanishing point detecting unit 103 and the path end position stored in the image memory B106.
Calculate.

That is, the position of the path end position calculated by the path end detection unit 105 on the lowest line of the image is determined by the X coordinate XA of points A' and C' in FIG.

By reading Xo, distances W1 and W2 of the automatic guided vehicle to the path ends 200 and 300 can be calculated using the following equations.

If point C' protrudes from the image due to the horizontal angle of view of the video camera 101, one of the detected passage ends 3
By extending 00 and finding the intersection with the bottom line, the coordinates of point C' can be easily read.

The direction and position information of the automatic guided vehicle calculated in this manner can be used, for example, to control the automatic guided vehicle so that it continues to travel on a line at a constant distance from the end of the path.

(Effects of the Invention) As explained above, in the present invention, the vanishing point position of the observation screen and the path end position are detected from the observation screen, and the direction of the automatic guided vehicle is crossed from the detected vanishing point position. The system is configured to calculate the distance of the automated guided vehicle from the end of the aisle based on the detected location of the end of the aisle, so the direction and position of the automated guided vehicle can be detected without using markers installed on the road or wall as in the past. Therefore, even if the layout of the factory is changed or expanded, there is no need to reinstall markers, making it highly versatile, and greatly reducing equipment costs.
There is no troublesome maintenance and management, and it is advantageous in terms of running costs.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of an embodiment of an automatic guided vehicle position detection device according to the present invention, FIG. 2 is a diagram explaining the principle of direction detection according to the present invention, and FIGS. 3 and 4 are according to the present invention. FIG. 5, which is a diagram explaining the principle of detecting the path end position, is a conceptual diagram showing the storage state of the path end position.

Claims (1)

[Claims] Vanishing point detection means for detecting the vanishing point position from the observation screen; Pathway end detection means for detecting the path end position of the automatic guided vehicle from the observation screen; and calculating the traveling direction of the automatic guided vehicle from the detected vanishing point position. 1. A position calculation device for an automatic guided vehicle, comprising: a position calculation means for calculating a distance of the automatic guided vehicle from a path end based on a detected path end position.