On designing controllers for a class of uncertain sampled-data nonlinear systems

The subject of this paper is the robust control of a class of sampled-data nonlinear systems with real time-varying parameter uncertainty and unknown cone-bounded nonlinearity. The authors consider the problems of robust stabilisation and robust performance in an H_infinity sense, and attention is focused on the design of linear dynamic sampled-data output feedback controllers. A control design methodology is proposed for solving both problems by recasting them into ´scaled´ H_infinity control problems for a related system which involve neither parameter uncertainty nor unknown nonlinearity.