Obstacle avoidance for redundant manipulators using directional-collidability/temporal-collidability measure

We present an efficient obstacle avoidance control algorithm for redundant manipulators using new measures called directional-collidability measure an d temporal-collidability measure. Considering relative movements of manipul ator links and obstacles, the directional-collidability/temporal-collidabil ity measure is defined as the sum of inverse of predicted collision distanc es/times between manipulator links and obstacles. These measures are suitab le for obstacle avoidance control since relative velocities between manipul ator links and obstacles are as important as distances between them. Also, we present a velocity-bounded kinematic control law which allows reasonably large gain to improve the system performance. Simulation results are prese nted to illustrate the effectiveness of the proposed algorithm.