Decentralized control of nonlinear interconnected systems

The asymptotic stabilization problem of a class of large-scale interconnected systems is considered where the nonlinear interconnections between subsystems are considered to be unknown and satisfy quadratic constraints that are functions of the overall system´s state vector. A decentralized combined observer-controller compensator is proposed and analyzed, where the subsystems´ state vectors are estimated using local sliding mode observers. The sliding mode observers are also employed to reconstruct the unknown nonlinear interconnections. The closed-loop system driven by the proposed decentralized compensator is guaranteed to be asymptotically stable subject to two conditions that are easily verifiable. Simulation results illustrate the effectiveness of the proposed decentralized combined observer-controller compensator design algorithm.