Using the redundant inverse kinematics system for collision avoidance

The present paper relates to the operation of robotic systems to avoid obstacles while positioning end-effectors. A new strategy to on-line collision-avoidance of the redundant robots with obstacles is presented. The strategy allows the use of redundant degrees of freedom such that a manipulator can avoid obstacles while tracking the desired end-effector´s trajectory. It is supposed that the obstacles in the workspace of the manipulator are static. The strategy is based on the redundant inverse kinematics and leads to the favorable use of the abilities of redundant robots to avoid the collisions with obstacles. This strategy has the advantage that the configuration of the manipulator can be influenced by further requirements such as joint limits, etc. The effectiveness of the proposed strategy is discussed by theoretical considerations and illustrated by simulation of the motion of the four-joint planar manipulators between symmetric obstacles. It is shown that the proposed collision-free strategy while tracking the end-effector trajectory is efficient and practical.