Approximation optimale H2 par systèmes structurés à retards entrées/sorties

In this paper, the H 2 optimal approximation of a n y × n u transfer function G(s) by a finite dimensional systemĤ d (s) including input/output delays, is addressed. The underlying H 2 optimal-ity conditions of the approximation problem are firstly derived and established in the case of a poles/residues decomposition. These latter form an extension of the tangential interpolatory conditions , presented in [1, 2] for the delay-free case, which is the main contribution of this paper. Secondly, a two stage algorithm is proposed in order to practically obtain such an approximation