Decentralized Adaptive Fuzzy Controller Design for Uncertain Large-Scale Systems with Unknown Dead-Zone

In this paper, a decentralized adaptive fuzzy controller is presented for a class of uncertain nonlinear large-scale systems with unknown dead-zone. Dead-zone characteristics are quite commonly encountered in actuators, such as hydraulic and pneumatic valves, electric servomotors, and piezoelectric transducer. Therefore, in addition to the uncertainties and interconnections in this system, controllers are often required to accommodate dead-zone uncertainties. For the controller design of uncertain nonlinear large-scale systems, we combine the robust control scheme with fuzzy approximators to approximate the unknown nonlinear functions of the system and the upper bound of the lumped uncertainty which is composed of interconnections and disturbances by some adaptive laws, respectively. Based on Lyapunov stability theorem, the proposed decentralized robust adaptive fuzzy control scheme can not only guarantee that all the signals involved are bounded but also obtain good tracking performance. Finally, an example and simulation results are provided to verify the effectiveness and performance of the proposed method.