Admittance Force Tracking Control for Position-Controlled Robot Manipulators Under Unknown Environment

Abstract

In this paper, a position-based impedance force control scheme of a robot manipulator is formulated from the simple impedance function that guarantees the desired force tracking performance under totally unknown environment. The position-based force control has a structural advantage of easy implementation for providing the force control capability to the existing position-controlled robot systems by closing a force control outer loop. Desired contact force tracking control in association with the time-delayed control on the environment is guaranteed without knowing any information on the environment such as position and stiffness a priori. The contact force is indirectly regulated by the positional correction terms after the proposed admittance filter controls the impedance force. Simulation studies on force tracking control tasks of a robot manipulator are performed to verify the proposition.