A robust scheme for indirect model reference adaptive control and its stability analysis

This paper presents a robust scheme for the indirect type of model reference adaptive control (MRAC) system, in the presence of unmodelled dynamics and measurement noise. This scheme is characterized by the use of adaptive law with dead zone and integral type of fixed compensator. Stability of the MRAC system is analyzed by employing the concept of L2δ norm and the Bellman-Gronwall lemma, based on the properties guaranteed by the adaptive law. Effectiveness of the scheme is demonstrated by the simulation carried out for a plant with first order nominal part.