Robust H∞ control for a class of uncertain nonlinear time-varying systems and its application

The problem of designing robust H^∞ controls for a large class of uncertain nonlinear time-varying systems involving parametric uncertainties, unmodelled perturbations, and external disturbances is addressed. A nonlinear H^∞ control technique is combined with the adaptive control technique and the variable structure control technique to construct a hybrid robust adaptive stabilisation controller that allows a H^∞ control to be achieved. Furthermore, the developed robust H^∞ stabilisation control scheme can be easily applied to the solution of robust tracking control design problems for a general class of uncertain nonlinear systems. A simulation problem involving the control of a nonlinear chaotic Chua´s circuit is solved to confirm the effectiveness and performance of the developed tracking control scheme.