Design of an interval type-2 fuzzy logic controller based on conventional PI controller

Interval type-2 fuzzy logic controllers have attracted much research interests in recent years due to their ability to cope with uncertainty. In this paper, we propose a systematical methodology to construct an interval type-2 fuzzy logic controller. The main contribution of this methodology is to generate the rule base of an interval type-2 fuzzy logic controller based on an existing conventional PI controller. As a consequence a linear control law is transformed to a nonlinear structure. Thus, the designer can benefit from the nonlinear structure of the proposed controller and the extra degree of freedom of type-2 fuzzy sets. The simulation results have shown that the proposed controller can manage the uncertainties much better than linear conventional PI and type-1 fuzzy logic controllers.