Computational aspects of IQC-based stability analysis for sampled-data feedback systems

Computational methods are proposed for stability analysis of sampled-data feedback systems with integral quadratic constraint (IQC)-characterized perturbations. It is shown that, for a given IQ, one can exactly evaluate that the IQC guarantees the closed-loop stability or not by computing the L/sub 2/-induced norm of a certain sampled-data system. An approximated search method is also proposed based on the fast-hold signals, which leads to an LMI.