A model reference approach to adaptive impedance control of robot manipulators

Abstract

A new formulation of the impedance control problem which is suitable for passivity based adaptive controllers for robot manipulators is proposed. A reference model architecture leading to a desired error dynamics and an adaptation procedure which is independent of the initial state error is used. The reference model dynamics represents the desired dynamics relationship between position error, velocity error and external force. It also allows for the adaptation procedure to be tuned independently of the desired impedance behavior of the manipulator. The proposed control algorithm is shown to be globally stable, computationally simple and easy to implement. The theoretical results are verified through computer simulations.