Adaptive Robust Control of a Class of Nonlinear Dynamic Systems Containing Partially Known Uncertainties

In this paper we deal with robust control of a class of nonlinear systems which contain partially known uncertainties. To cope with the uncertainties an adaptive controller is proposed and both the uniform boundedness of all the closed-loop signals and uniform ultimate boundedness of the system state are guaranted. In contrast with some previous attempts to relax some a priori knowledge on the uncertainties bounds by using a discontinuous control law [8], in this paper we propose a continuous control law. Hence chattering problems (which have practical importance) can be avoided. The results are illustrated with motion control of rigid robot manipulators.