DELAY-DEPENDENT CONTROL FOR LARGE-SCALE SYSTEMS BASED ON A NEW DECENTRALIZED DYNAMIC FUZZY CONTROL ARCHITECTURE

A delay-dependent guaranteed cost controller design method for nonlinear interconnected uncertain large-scale systems with time delays which can be represented by extended Takagi-Sugeno (T-S) fuzzy models is presented. A new decentralized dynamic fuzzy controller architecture with dual index rule base is proposed in the form of an observer-based state feedback incorporating dynamic output feedback, which makes it possible to improve system stability and satisfy the desired guaranteed cost performance simultaneously under the circumstance that not all states are available. Based on less conservative delay-dependent Lyapunov functional approach, some sufficient conditions for the existence of controller are provided in terms of LMI dependent on the upper bound via substituting vector method. The upper bound of time-delay can be obtained using convex optimization such that the system can be stabilized for all time delays whose sizes are not larger than the bound. A minimization problem procedure is also proposed to search the suboptimal upper bound of guaranteed cost function. Finally, the better control performances of the proposed method are shown by the simulation examples.