Adaptive impedance force control of an industrial manipulator

Abstract

The paper deals with adaptive impedance control and its application to the problem of industrial robot control with the end-effector contacting the environment. The position-based impedance control scheme is employed providing a mass-spring-damper behavior of the robot end-effector. Due to unknown parameters of the environment (stiffness, exact position) additional adaptive terms are included to assure the system stability despite the lack of knowledge of the environmental parameters. A model reference algorithm is proposed which differs from classical algorithms in its method of excitation. Adaptive impedance controller implementation results for industrial 5 DOF anthropomorphic robot ASEA IRb 6 are outlined and discussed.