A type-2 fuzzy logic controller for the liquid-level process

This paper focuses on evolving type-2 fuzzy logic controllers (FLCs) genetically and examining whether they are better able to handle modelling uncertainties. The study is conducted by utilizing a type-2 FLC, evolved by a genetic algorithm (GA), to control a liquid-level process. A two stage strategy is employed to design the type-2 FLC. First, the parameters of a type-1 FLC are optimized using GA. Next, the footprint of uncertainty is evolved by blurring the fuzzy input set. Experimental results show that the type-2 FLC copes well with the complexity of the plant, and can handle the modelling uncertainty better than its type-1 counterpart.

[1]  Francisco Herrera,et al.  Genetic Fuzzy Systems - Evolutionary Tuning and Learning of Fuzzy Knowledge Bases , 2002, Advances in Fuzzy Systems - Applications and Theory.

[2]  J. Yen,et al.  Fuzzy Logic: Intelligence, Control, and Information , 1998 .

[3]  Cao Xiu.  Application of Fuzzy Control in Industrial Process , 2002 .

[4]  Masatoshi Sakawa,et al.  Genetic Algorithms and Fuzzy Multiobjective Optimization , 2001 .

[5]  Zbigniew Michalewicz,et al.  Genetic Algorithms + Data Structures = Evolution Programs , 1992, Artificial Intelligence.

[6]  Abdollah Homaifar,et al.  Simultaneous design of membership functions and rule sets for fuzzy controllers using genetic algorithms , 1995, IEEE Trans. Fuzzy Syst..

[7]  Bernard P. Zeigler,et al.  Designing fuzzy net controllers using genetic algorithms , 1995 .

[8]  Jerry M. Mendel,et al.  Uncertainty bounds and their use in the design of interval type-2 fuzzy logic systems , 2002, IEEE Trans. Fuzzy Syst..

[9]  P.J. King,et al.  The application of fuzzy control systems to industrial processes , 1977, Autom..

[10]  Lotfi A. Zadeh,et al.  Outline of a New Approach to the Analysis of Complex Systems and Decision Processes , 1973, IEEE Trans. Syst. Man Cybern..

[11]  Khalid Marzuki,et al.  TUNING OF A NEURO-FUZZY CONTROLLER BY GENETIC ALGORITHMS WITH AN APPLICATION TO A COUPLED-TANK LIQUID-LEVEL CONTROL SYSTEM , 1998 .

[12]  Kim Fung Man,et al.  Genetic algorithms for control and signal processing , 1997, Proceedings of the IECON'97 23rd International Conference on Industrial Electronics, Control, and Instrumentation (Cat. No.97CH36066).