Development of a real-time range finder interpolating the parallax signals for surfaces

In order to apply "eyes" to an autonomous running vehicle, a real-time range finder has been developed that can measure both the distance to every point on a plane without any pattern and its inclination. Although it seems contrary to the fact that the parallax is inversely proportional to the distance, this paper derives the mathematical ground that a plane in a real 3-D space (X,Y,Z) is mapped also into the plane in a spatial parallax (x,y, Δx). On this basis, an electronic circuit has been manufactured which can compute in video rate the interpolation value between the parallaxes at two characteristic points by using several programmable logic devices. It has also been demonstrated that this device is applicable to the measurements of the slant angles of and the directions normal to a simple plane or a slightly curved surface.