An example of adaptive fuzzy control design with the use of frequency-domain methods

Abstract

This paper presents an example of adaptive fuzzy control design for an unstable plant with a pole changing location in the right half-plane. The design procedure utilizes the Nyquist and the circle stability criteria that can be graphically tested using Nyquist plots. It is assumed that the function of the fuzzy controller is a nonlinearity described by a sector condition. An adaptation mechanism ensures that during adaptation this function stays in a safe sector.