A fast method for cylindrical object location determination

In this paper, a simple and fast geometrical single-view method is proposed to determine the location of labelled cylindrical objects in the 3-D space. For a robot, to fetch the desired cylindrical object, two problems have to be solved. They are the identification of the cylindrical object, and the determination of the object's location relative to the robot. In the proposed method, a known-height label is pasted on the cylindrical object, on which an object code is associated for the robot to identify the desired object. For determining the location of the object, three-dimensional vector analysis and simple algebraic computation are applied to achieve the high speed requirements. This approach has the advantage that it needs not to know any intrinsic camera parameter. An analysis of location errors for different positions is included. Simulation results show that the location determination time is about 0.2 sec in a 20 MHZ IBM compatible PC/AT computer system, and the location error is less than 2% in average.