Sampled-data modeling and control of nonlinear systems

Most research in control of nonlinear systems is devoted to continuous time systems, the discrete time models being not well defined and difficult to handle. In this paper, an attempt to obtain equivalent discrete time models for sampled data control system is presented. Although the class of nonlinear systems is restricted to the so called sampled data computable nonlinear systems, it is also shown how broad the class of systems suitable to be expressed by this form is. Some properties of these models are also analyzed and a methodology to design sampled data controllers is outlined. A dual rate framework, faster for updating the control signals and slower to evaluate the controlled system behavior, is used to implement multirate controllers.