Abstract: A new physical meaning of manipulability is given. Reduced manipulability is analyzed, and arm length index and rotation angle index which express fault tolerant workspace and actual manipulability respectively are proposed. Synchronous fault tolerant planning of joint motion and end-effector motion is researched through simulation examples for a planar 3R manipulator. Research results show that the maximization of rotation angle index can avoid the singular configuration of the reduced manipulator at failure moment, while the maximization of arm length index can avoid the singular configuration of the reduced manipulator after the failure.

Key words: Manipulator, Redundancy, Synchronous fault tolerant planning