A new frequency-domain subspace algorithm with restricted poles location through LMI regions and its application to a wind tunnel test
In this paper, an innovative method is presented to identify models with a modified frequency-domain subspace method. This new approach allows to introduce in the subspace resolution constraints on the identified model poles location. Here, a very general formulation is proposed to take into account regions in continuous/discrete map. This formulation is based on an LMI (linear matrix inequalities) description where the stability domain represents a particular case. These LMI constraints are combined with the frequency-domain subspace resolution to obtain identified models whose poles are situated in the specified LMI regions. This approach is benchmarked with the Loewner one, which belongs to the class of frequency-domain input–output model identification and approximation methods. Besides the fact that they both belong to the data-driven model approximation class, they result to have slightly different objectives and show complementary performances. This discussion is illustrated in practice with experimentations that have been performed for the identification and control of the gust disturbance over a 2D wing span, from sub to transonic, in a wind tunnel facility.