R.Shashi Kumar Reddy,M.S.Teja,M. Sai Kumar,Shyamsunder Merugu,



Analytical structures,fuzzification,defuzzification,fuzzy Proportional plus Derivative controllers,membership functions,MATLAB/simulink,


The present paper deals with the comparison of output performance of fuzzy Proportional plus Derivative controller with conventional controllers. Fuzzy PD controller having 2 fuzzy sets for everyi/p variable and 3 fuzzy sets for o/p variable in the universe of discourse. Mathematical input-output relationships of simple fuzzy Proportional plus Derivative controller is developed via arbitrary membership functions for fuzzification, Zadeh AND operation for the evaluation of antecedent part of the rules and centroid method for defuzzification. Computer simulations show the effectiveness of Fuzzy Proportional plus Derivative controllers over the conventional controllers for time delay and nonlinear systems by choosing Triangular and Trapezoidal membership functions as input and output fuzzy sets. As a case study P.M.D.C. Servo system with saturation nonlinearity is considered with load disturbance and without load disturbance. MATLAB environment developed results are added to show the importance of the fuzzy controllers for P.M.D.C. Servo system with saturation nonlinearity with and without load disturbance using Triangular and Trapezoidal membership functions as input and output fuzzy sets.   


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