SYSTEMATIC DESIGN OF ROBUST CONTROLLERS FOR NONLINEAR UNCERTAIN SYSTEMS

The design problem of robust stabilizing controllers for nonlinear unc ertain systems is considered in this paper. The nominal system is inpu t-output linearizable, and the uncertainty is assumed to be either gen eralized matching or mismatched. The control design combines different ial geometric feedback linearization with the deterministic approach, in which no statistical property of the uncertainty is assumed and use d; the only information on the uncertainty, which is needed for the de sign, is its possible bound. Two robust stabilizing controllers for ge neralized matching uncertain systems are given. For mismatched uncerta in systems, a systematic design procedure is first presented, then fou r robust stabilizing controllers are given. The robust controllers, wh ich are given in forms of explicit feedback laws based on the nominal system and are parametrized by the robust design parameters related to the bounds of uncertainties, are more practicable than the existing o nes in the literature. Numerical examples and simulation results verif y the effectiveness of the design method and controllers.