Obstacle avoidance of a redundant robot using virtual force field and null space projection

Abstract

This paper presents a novel algorithm for redundant robot control when obstacles are approaching to the robot. The proposed controller is constructed by a multi-hierarchy control framework where a main task controller is designed to track a given Cartesian space trajectory and an extra impedance controller is developed in the null space to guarantee compliant joint motion. A virtual force field is designed and applied on the robot body to achieve the goal of the avoidance of the obstacle. Simulation studies illustrated the proposed controller is not only to guarantee the task space control, but also able to avoid the obstacle by joint movements.