Stability analysis of a sliding observer based robust output tracking control design for a nonlinear system

An observer based robust output tracking controller design is proposed for a class of nonlinear systems which are input-output linearizable. An ultimate boundedness analysis is presented for an equivalent control based sliding observer where the estimation accuracy is eventually expressed in terms of a single parameter. The observer is incorporated into the closed loop to implement an ideal tracking control law and a complete Lyapunov observer/controller synthesis is performed to prove the ultimate boundedness of the tracking error.