Abstract
We now develop an active type of positioning system for roboted vehicle moving on three dimensional space by use of a laser beam and a corner cube (retroreflector). In this system a vehicle, first, searches a corner cube target fixed on a ground reference point and emits a laser beam toward the target. When the laser beam captures the target, the vehicle geometrically determines the own position and attitude based on the directions of the target measured by the laser beam.
In order to continue the accurate position finding even during movement of the vehicle, the above positioning system requires a laser tracking control which always directs the laser beam toward the center of corner cube target.
This paper presents a laser tracking control method. First we show that the directional deviation of the laser beam relative to the center of target, which is needed for accurate tracking control, is easily determined by the active use of unique reflectional characteristics of the corner cube. Then we design the laser tracking controller on which the feedback gains are obtained based on LQ regulator theory. Further we show the capability of our proposed tracking method through some experiments using a proto-type system.
