Fault-tolerant control of redundant robots by dual-optimization

There is a need for robots that are more flexible and reliable than the fixed configuration models currently available. Redundant robots provide an alternative to satisfy this requirement because redundancy can be used to improve the kinematic performance and compensate for joint failures. Due to the uncertainty of potential failures and large accumulated path errors, the instantaneous joint torques may increase and exceed actuator limits during the system recovery process. We propose to alleviate this difficulty by the use of optimal redundancy control, an approach that simultaneously takes into account both kinematics and dynamics. To realize dual-optimization control, a dynamically redundant mechanism with local degrees of freedom is introduced, and its use for redundancy control is investigated. Simulation results demonstrate the proposed method