A software development for the simulation of type-2 fuzzy logic systems

The concept of type-2 fuzzy set was initially proposed as an extension of classical (type-1) fuzzy sets. Type-2 fuzzy sets are very useful in circumstances where it is difficult to determine an exact membership function for a fuzzy set; hence they are very effective for dealing with uncertainties. However, type-2 fuzzy sets are more difficult to use and understand than type-1 fuzzy sets. Even in the face of these difficulties, type-2 fuzzy logic has found applications in many fields. Currently, there are some commercial software programs like Fuzzy Logic Toolbox of MATLAB/SEVIULINK in which the simulation of type-1 fuzzy logic systems can be done easily but, there is no such a commercial software program for the simulation of type-2 fuzzy logic systems. Therefore, in this thesis, a new Type-2 Fuzzy Logic Toolbox written in MATLAB programming language is designed for direct applications of type-2 fuzzy logic in MATLAB and SIMULINK. Type-2 Fuzzy Logic Controller Block is also prepared for use in SIMULINK. Since general type-2 fuzzy logic systems are very complicated, they are not preferred in applications. Thus, only interval type-2 fuzzy logic systems are considered in the proposed Type-2 Fuzzy Logic Toolbox. All the menus of the developed software package are in the same format with MATLAB Fuzzy Logic Toolbox and are prepared in English for international use. Keywords: Type-2 Fuzzy Logic, type-2 fuzzy sets, interval sets, type-2 fuzzy logic toolbox.