Achieving impedance objectives in robot teleoperation

Abstract

This work describes the experimental application of impedance control to a seven joint revolute manipulator built for neutral buoyancy operation. Compensator design methodologies previously applied to a single joint are extended to the full manipulator and tested in 1 g tasks. The controller was configured to mimic three useful modes at the end-effector: accommodation control, spring-dashpot control, and inertial mode. Simulated parameter errors were negligible even for outer force loop rates as low as 40 Hz. Hard contact tasks typically required damping augmentation of 5-10 times the freespace values to maintain stable contact. Preliminary experiments indicate that this controller can be a useful tool in fulfilling future objectives in space telerobotic operations.