Impedance Control of Flexible Joint Robots Based on Singular Perturbation Method

This paper addresses the issue of impedance control of robot manipulators with joint flexibility. First, by using singular perturbation method dynamics of the links (i.e. the joint motion on the link side) and flexible joints are described with a slow motion equation and fast motion equation, separately. Second, an impedance control subsystem is designed for the slow subsystem to meet the desirable impedance dynamics designed in the workspace, and then, a joint vibration control subsystem is designed based on the fast motion model to ensure stability of the system. Simulations are carried out on a two-link flexible joint robot. The results demonstrate the effectiveness of the proposed impedance control method.