Analytical structures and analysis of fuzzy PD controllers with multifuzzy sets having variable cross-point level

This paper deals with fuzzy PD controllers which employ N(greater than or equal to 3) input fuzzy sets with variable cross-point level and 2N - I output fuzzy sets. Analytical structures of fuzzy PD controllers are derived using triangular membership functions for fuzzification, rule base with four linear control rules, two different triangular conorms (Lukasiewicz OR and Zadeh OR), different inference methods such as Mamdani's minimum, Larsen's product and drastic product, and center of area method for defuzzification. Properties of such fuzzy PD controllers are studied. Influence of variable cross-point level on controller performance is demonstrated with an example. (C) 2002 Elsevier Science B.V. All rights reserved.