Title :
Real-time failure-tolerant control of kinematically redundant manipulators
Author :
Groom, Kenneth N. ; Maciejewski, Anthony A. ; Balakrishnan, Venkataramanan
Author_Institution :
Purdue Univ., West Lafayette, IN, USA
fDate :
12/1/1999 12:00:00 AM
Abstract :
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. Comparisons show that the performance of the best method is indistinguishable from that of brute-force implementations. An example demonstrating the real-time performance of the algorithm on a commercially available seven degree-of-freedom manipulator is presented
Keywords :
Jacobian matrices; fault diagnosis; fault tolerance; position control; redundant manipulators; singular value decomposition; brute-force methods; end-effector trajectory; fault-tolerance measure; kinematically redundant manipulators; minimum singular value; post-failure Jacobians; real-time failure-tolerant control; seven degree-of-freedom manipulator; single locked-joint failures; worst-case quantity; Fault tolerance; Jacobian matrices; Kinematics; Manipulators; Mobile robots; Redundancy; Robot sensing systems; Robotics and automation; Service robots; Servomechanisms;
Journal_Title :
Robotics and Automation, IEEE Transactions on