Coordinated decentralized output-feedback MRAC: The case of MIMO subsystems with delayed communications

An exact decentralized output-feedback certainty-equivalence Lyapunov-based design of direct MRAC for linear interconnected systems with SISO subsystems has been recently introduced in the literature. The design uses a new coordinated decentralized structure of adaptive control with reference model coordination which requires an exchange of signals between the different reference models, but does not involve the exchange of output signals between the different subsystems. It can not only guarantee closed-loop stability but also asymptotic zero tracking errors. In this paper we use this idea to construct DMRAC for tracking of linear systems with MIMO subsystems and delayed interconnections. The resultant decentralized control with multi-controller architecture guarantee stability and convergence of the output errors to zero asymptotically, by local output-feedback. Two adaptive schemes of DMRAC are proposed. This represents the first asymptotic exact zero tracking results for this class of systems.