Design of a model identification fuzzy adaptive controller and stability analysis of nonlinear processes

This paper deals with the design of a model identification fuzzy adaptive controller with real-time scaling factors adjustment and the stability analysis of nonlinear distributed parameter systems. The solution branch of such systems frequently contains limit points (or turning points) which represent the boundary between stability and instability of the system. Hence, stability analysis is required for the determination of the stable and unstable operating regions. The performance of the proposed fuzzy self-tuning controller is compared to an equivalent conventional adaptive controller, over a wide range of step disturbances and operating regions. The proposed fuzzy adaptive scheme in comparison with the conventional adaptive scheme exhibits a much robust response, shorter settling times, overshooting less the controlled variable and smaller IAE of the manipulated variable for the entire range of step disturbances. (C) 2001 Elsevier Science B.V. All rights reserved.