A regressor-free adaptive impedance controller for robot manipulators without Slotine and Li's modification: theory and experiments

Abstract

SUMMARY Slotine and Li's modification is a well-known, simple, and elegant approach for robot adaptive control to avoid the feedback of joint accelerations. This paper presents a simple strategy to implement a regressor-free adaptive impedance controller without using Slotine and Li's modification. In the new strategy, the joint acceleration vector and the dynamics of robot are assumed to be unavailable. Their effects are covered by using the function approximation technique so that there is no need for the joint acceleration feedback. The closed-loop stability and boundedness of internal signals are justified by the Lyapunov-like technique. Experimental results for a two-dimensional (2D) robot are presented to show the effectiveness of the proposed strategy.