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 c ontroller with real-time scaling factors adjustment and the stability analy sis of nonlinear distributed parameter systems. The solution branch of such systems frequently contains limit points (or turning points) which represe nt the boundary between stability and instability of the system. Hence, sta bility analysis is required for the determination of the stable and unstabl e operating regions. The performance of the proposed fuzzy self-tuning cont roller 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 exhibi ts a much robust response, shorter settling times, overshooting less the co ntrolled variable and smaller IAE of the manipulated variable for the entir e range of step disturbances. (C) 2001 Elsevier Science B.V. All rights res erved.