Control of temperature using fuzzy system tehnique

Fuzzy control is based on fuzzy logic. A logical system that is much closer in spirit to human thinking and natural language than traditional crisp logical systems. The fuzzy logic variables are not described as true or false values. Instead values range in degree between 0-1,true-false or yes-no. Fuzzy logic provides as a means of converting with linguistic control strategy.This strategy rules are based on expert knowledge that is invented by a plant operator or a design egineer. Especially the exposition includes a discussion of fuzzification and defuzzification strategies,the derivation of the database and fuzzy control rules,the definition of fuzzy implication and an analysis of fuzzy reasoning mechanisms. Fuzzy logic is used in machine control widely .Although genetic algoritms and neural networks can perform as well as fuzzy logic in many cases. In the other hand fuzzy logic has advantage that the solution of problem can be formalize terms in that human operators can understand easily so their experience can be used in the design of the controller. Fuzzy controller is generally nonlinear because it doesn’t have a simple equation like the PID ,but also PID control is not convenient in that case of higher-order plants.The fuzzy controllers appear in consumer products.For instance washing mashines,video cameras,underground trains and robots.A fuzzy controller acts or regulates by means of rules in a more or less natural language based on the distinguish feature: fuzzy logic