Robustness via structured H∞/H∞synthesis

摘要

Multi-objective H∞/H∞-synthesis with structured control laws is discussed and used as a means to enhance robustness of the system in the presence of real parametric uncertainty. NP-hardness of the computation of the structured singular value μ excludes its use within an optimisation procedure and raises the question of how to replace it. We show that the semi-structured distance to instability can be used for that purpose and we indicate how the resulting mixed H∞ program can be solved efficiently. The method is applied to the regulation of a flexible geostationary satellite.