Development of a laser sensor for in-process guidance of an industrial robot

Abstract

A pilot-type laser sensor for non-contacting distance measurement has been developed, which was aimed at application to in-process guidance of an industrial robot. A laser beam is emitted through a convex lens to an object and the reflected light is collected and focused by the lens. Diameter of its unfocused image is measured using one dimensional CCD-array, from which the distance is determined. Because the way of the beam emission and that of reflected light to the lens are the same, scanning of the beam to follow a path for robot guidance is easy and some geometric constraints, which may arise for a sensor using triangular principle, are removed. Geometric analyses for scanning the beam with a mirror are presented to determine the distance and position of an object point. A simple tracking control theory for the beam to follow a path and give informations about its position to a robot controller has been suggested and analyzed.