An adaptive impedance control algorithm; Application in exoskeleton robot

Abstract

Exoskeleton is a well-known example of an unconstrained robot for which the desired path is not predefined. Regarding these two effective features, a formulation for impedance control algorithm is presented and its prominence is demonstrated both mathematically and through simulation. Moreover it is essential to control this robot by an adaptive method because at least dynamic characteristics of the load are unknown. Unfortunately the existing methods do not address aforementioned traits or become unstable as inertia matrix becomes singular. Here an adaptive algorithm is generated based on the logic of Least Squares identification method rather than the Lyapunov stability criterion to tackle those limitations.