Optimal discretization of continuous-data control system

Two methods of simulating continuous-data systems by sampled-data models are presented. Sample-and-hold devices are inserted in an otherwise continuous-data system, and the input and the feedback gains are modified to make the response of the sampled-data model as close to that of the original system as possible. A point-by-point comparison method matches the state variables of the two systems at the sampling instants. Another method relies on the optimization of the sampled-data system with a quadratic performance index.