H-infinity decentralised output feedback preview tracking control via state observer for a class of nonlinear disturbed interconnected discrete systems

This paper presents an observer-based decentralized H-infinity output feedback preview tracking control method for a class of nonlinear disturbed interconnected discrete systems. The considered output tracking control problem, for the first time, is transformed into a H8 controller design problem of N augmented error subsystems. For each subsystem, the suggested control law is formulated by a combination of integral control action, observer-based state feedback control action and preview feedforward action of this subsystem. Based on the Lyapunov function approach, the auxiliary matrix variable approach, and some special mathematical manipulations, the controller feasibility conditions are established in linear matrix inequality (LMI) framework to guarantee the existence of the offered observer-based decentralized H-infinity preview tracking controller. And, the gain matrices of both decentralized observation and decentralized tracking control can be searched concurrently by only one-step LMI procedure. Finally, two examples are presented to verify the effectiveness and superiority of the proposed controller.