Failure tolerant teleoperation of a kinematically redundant manipulator: an experimental study

Teleoperated robots in harsh environments have a significant likelihood of failures. A common type of failure such as that of a joint “locking up”, when unidentified by the robot controller, can cause considerable performance degradation in the local behavior of the manipulator even for simple point-to-point motion tasks. The effects of a failure become more critical for a system with a human in the loop, where unpredictable behavior of the robotic arm can completely disorient the operator. In this experimental study involving teleoperation of a graphically simulated kinematically redundant manipulator, two control schemes, the pseudo-inverse and a proposed failure-tolerant inverse, were randomly presented under both non-failure and failure scenarios to a group of operators. Based on the performance measures derived from the recorded trajectory data and operator responses, it is seen that the failure-tolerant inverse kinematic control scheme improved the performance of the human/robot system