A Nonlinear Fuzzy PID Controller via Algebraic Product AND-Maximum OR-Height Defuzzification

This paper reveals a new mathematical model of the simplest fuzzy PID controller which employs two fuzzy sets ( negative and positive) on each of the three input variables (error, change in error and double change in error) and four fuzzy sets (-2, -1, +1, +2) on the output variable (incremental control). L - type, Gamma- type and Pi - type membership functions are considered in fuzzification process of input and output variables. Controller modeling is done via algebraic product AND operator-maximum OR operator-Height (Ht) defuzzification process combination. The new model obtained in this manner turns out to be nonlinear, and its properties are studied.