Control a Redundant Robot Using Visual Information. Avoidance Control of a Moving Obstacle.

Abstract

Generally, a redundant robot has been used to avoid a static obstacle in industrial production systems. In this paper, a control method of a redundant robot for avoidance of a moving obstacle using visual impedance is proposed. Two CCD cameras are used to construct a stereovision, and a high-speed image processing board with a built-in DSP processor is used for image input and real time processing. When an obstacle moving into a previously established virtual potential field around the links of a robot is detected, a virtual torque is generated by the proposed method. A criterion function including the manipulability of arm and the distance between obstacle and the link is proposed for selection of a redundant joint. A control algorithm is also developed to complete both a tracking task by an end-effector and a task of obstacle avoidance by a redundant joint at same time. The effectiveness of the proposed method has been demonstrated through the avoidance experiments.