An approach to robust control of sampled-data systems having finite-dimensional LTI and parametric uncertainties

Robust performance of sampled-data control for uncertain finite-dimensional LTI systems with structured and parametric uncertainties is considered. It is shown that the small gain condition with dynamic scaling implies robust performance and robust internal stability in spite of their time-varying characteristics. It is demonstrated that to prove the sufficiency, the argument of equivalence between stability and performance problems is unnecessary. This paper also shows that dynamic scaling gives a less conservative condition even when considering stability against unstructured uncertainty. A frequency response approach to analysis and synthesis problems is proposed