Robustly stable active structural control

Due to various model uncertainties, most existing control strategies may lead to arbitrarily small stability margins. This paper presents an H2/H2 nested control synthesis which combines advantages of the classical H2 and H2-approaches, and guarantees robust stability. Special H2-maximum and H2-ultimate system norms are introduced by generalizing the concept of the standard L1, H2 and H2 norms. These norms reduce the conservatism of the control design specifications while retaining all the benefits of the standard H2-norm. Both stochastic and deterministic interpretations are addressed. The effectiveness of the new method is illustrated by a numerical example.