Robust decentralized fuzzy control for process control

This paper gives a robust decentralized fuzzy control design for process control. Given a nonlinear process, it is first broken into a set of interconnected subsystems, then a decentralized controller is designed for each subsystem. Direct approach to this problem by using fuzzy logic systems (FLSs) to approximate the unknown ideal control law is followed, and the semi-global stability is established based on the Lyapunov analysis. Besides the usual advantages of a decentralized control, the proposed control has the following features: ability to incorporate in a transparent way an existing control experience into the controller design, robustness to a wide range of uncertainties, reduced a priori information on the nonlinear system and on-line computation load required for its implementation, and semi-global exponential output tracking to the reference signals up to a ultimately bounded error. An application of this scheme is considered through simulations in a level control problem.