Decentralized control using reduced-order unknown input observers

The output feedback stabilization problem of a class of nonlinear interconnected systems is considered. A novel decentralized dynamic output feedback controller is proposed, where local, projection operator based, reduced-order observers are employed to estimate the subsystems’ states. The proposed design algorithm is characterized by the separation property of the observer-controller design. The closed-loop system driven by the proposed decentralized dynamic output feedback controller is asymptotically stable. The effectiveness of the proposed control strategy is illustrated with simulation examples.