Abstract
In this paper, we propose a tuning method in which the membership functions in a fuzzy controller can be set up simply by utilizing the knowledge of tuning parameters in a conventional PID controller. In the method proposed here, fuzzy control is realized by applying the simplified inference method to only four simple fuzzy control rules, in which the piecewise linear membership functions determined by the knowledge are used in the antecedent part.
Therefore, we first show that PI control can be realized by using the linear membership functions in the antecedent part of the above fuzzy control rules. Then, we show that the piecewise linear membership function used in the proposed fuzzy control can be determined easily by the composition of two different linear membership functions. Finally, from the results of the simulation for the first- and second-order lag systems with dead time, we show the effectiveness of this fuzzy controlin improving control performance, compared with a conventional type of fuzzy control using the triangular membership functions.
