Robustness analysis of sampled-data feedback systems

Presents a procedure for analyzing the robustness properties of closed-loop systems with sampled-data controllers. Beyond the outline of the theoretical results for discrete-time μ-analysis the major result of the paper is the investigation of the choice of weights for the sectors of the samplers. It is shown in the examples how the weights can be chosen so that the impact of the approximation errors are reduced significantly. Hence conic sectors for robustness evaluations need not be conservative. The results of the paper presents a first step towards systematic procedures for the selection of sampling-rate and of discretization methods for discrete-time implementation of continuous-time controllers in the face of structured uncertainties