Real-Time Failure Tolerant Control of Kinematically Redundant Manipulators

K. N. Groom, A. A. Maciejewski, and V. Balakrishnan

In Proc. IEEE Int. Conf. Robotics and Automation, pages 2595-2600, Albuquerque, New Mexico, April 1997

Winner, best student paper award

Abstract: This work considers real-time fault-tolerant control of kinematically redundant manipulators to single locked-joint failures. The fault-tolerance measure used is a worst-case quantity, given by the minimum, over all single joint failures, of the minimum singular value of the post-failure Jacobians. Given any end-effector trajectory, the goal is to continuously follow this trajectory with the manipulator in configurations that maximize the fault-tolerance measure. The computation required to track these optimal configurations with brute-force methods is prohibitive for real-time implementation. We address this issue by presenting algorithms that quickly compute estimates of the worst-case fault-tolerance measure and its gradient. Real-time implementations are presented for all these techniques, and comparisons show that the performance of the best is indistinguishable from that of brute-force implementations.

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