Abstract  We present an efficient obstacle avoidance control algorithm for redundant manipulators using new measures called directional-collidability measure and temporal-collidability measure. Considering relative movements of manipulator links and obstacles, the directional-collidability/temporal-collidability measure is defined as the sum of inverse of predicted collision distances/times between manipulator links and obstacles. These measures are suitable for obstacle avoidance control since relative velocities between manipulator 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 presented to illustrate the effectiveness of the proposed algorithm.