ABSTRACT
In this chapter, the authors discuss internal relations between fuzzy controllers and proportional-integral-derivative (PID) controllers. Based on the interpolation property of fuzzy controllers, they first point out that a fuzzy controller with one input and one output is a piecewise P controller. Since fuzzy logic was first introduced by Lotfi Zadeh in 1965, there are tremendous studies and successes in fuzzy control applications. In practice, the PID gains are usually tuned by expertises. However, some studies have shown that the gains can be tuned systematically. The authors show that a fuzzy controller has stronger control capability than traditional PID controllers because a nonlinear term is included in the fuzzy controller.
