The design of control strategies tolerant to unidentified failures in kinematically redundant manipulators

The use of robots in hostile environments significantly increases the likelihood of failures in the robot´s subsystems. Existing techniques for developing failure tolerant robots rely on effective failure detection and identification. Since failure identification is itself a difficult process that may not always be successful, it is important to consider the behavior of the robot prior to identification of a fault, or even the possibility of failures remaining unidentified. This work proposes control strategies that improve local measures of failure tolerance for kinematically redundant robots experiencing unidentified locked-joint failures. Measures to evaluate the fault tolerance capability of the various schemes are presented and the performance of the proposed schemes are demonstrated with an example