“…Current approaches to the describing function method used in the stability analysis of FCSs deal with the following applications of this method: in the form of the exponential-input describing function technique to FCSs using the representations of the FCs as multidimensional-multilevel relays (Abdelnour, et al, 1993a(Abdelnour, et al, , 1993b; to FCSs based on Mamdani FCs without dynamics (Passino and Yurkovich, 1998); to multivariable Takagi-Sugeno FCSs (Cuesta, et al, 1999); to FCSs based on FCs with dynamics, by using the describing function of the saturation which occurs outside the input universes of the FCs (Aracil and Gordillo, 2000). All these approaches require the prediction of the limit cycles, specific to the describing function method (Kim, et al, 2000).…”