Control of redundant manipulators for task compatibility

When called upon to perform a manipulation task, through experience we place our arm in a posture which is best suited for performing that task. Posture variation is a means through which the motion and strength characteristic of the arm is made compatible with the task requirements. We propose an index for measuring the compatibility of an arm posture with respect to fine manipulation tasks, where accurate control of small velocity and force is required, and coarse manipulation tasks, where exertion of large velocity and force is required. The optimization of this index presents an effective way of utilizing manipulator redundancy. The resultant manipulator postures closely resemble those used by humans in performing similar tasks.