Two-time Scale Sliding Control of Manipulators with Flexible Joints

Abstract

This paper applies a two-time scale sliding control approach to the control of robot manipulators with flexible joints in the presence of model uncertainty. A singular perturbation model is used to decompose the manipulator dynamics into a slow and a fast submodel, using the concept of slow manifold. A slow sliding controller is designed in order to account for parametric uncertainty on the slow manifold. Further, a fast sliding controller guarantees that the slow manifold is attractive (i.e. all fast system trajectories converge to the slow manifold) despite parametric uncertainty.