Dynamic Impedance Control of a 6 DOF Robot Arm

Abstract

This paper develops a contact-control scheme for multi-degree-of-freedom (DOF) robot arms that relies on dynamic impedance to jointly improve precision, stability, and robustness. Classical impedance controllers keep stiffness, damping, and inertia fixed, which limits how well they adapt as operating conditions change. Here an impedance model is built specifically around the end-effector, and position control is refined by adding force-based corrections to the desired position along the force- controlled axes. Dynamic impedance is realized by tying the impedance parameters to the joint angles and angular velocities, using the final value theorem together with quadratic-form transient-response analysis. The resulting method is validated in MATLAB/Simulink through wall-wiping simulations performed with a 6-DOF RPY-type robot.