Autonomous Contouring Control of an Articulated Robot

Abstract

Contouring control of a robot arm is a significant problem in many manufacturing processes, such as arc-welding, sealing, painting, shape measuring and various inspections. For this control play-back control has been applied so far. But it has following inherent problems.i) Play-back control requires much time and labour in the teaching process.ii) Play-back control system cannot adapt itself to setting errors and to individual differences of objects.iii) Control performance depends directly upon the operator's teaching ability and upon how accurately objects are placed.We proposed Autonomous Contouring Control of a robot arm in order to overcome those problems. In this control the robot system obtains the information about the position and the shape of the object using the sensors attached to the robot hand.In this paper we analyzed the basic characteristic of Autonomous Contouring Control System in two dimensional case. Based upon the analysis we proposed a scheme for the control system design. And then applying the scheme to an articalated robot arm driven by hydraulic cylinders, we verified its effectiveness for contouring control of unknown curves by experiments.