MRAC using observers with unknown inputs

In this paper we present a model reference adaptive control scheme for plants with unity relative degree. The novelty of this approach is that the model reference need not be strictly real positive and the method uses the theory of observers with unknown inputs. Eventhough the analysis starts very general, the same basic assumptions for the MRAC are encountered when proving stability of the proposed method, but from a different viewpoint. Simulation results are included to compare the new approach with the standard MRAC.