Marginal linearization method in modeling on fuzzy control systems. (Q1407816)

The marginal linearization method in the modeling of fuzzy control systems is proposed; it deals with a nonlinear model with variable coefficients. The method can turn a nonlinear model with variable coefficients into a linear model with variable coefficients in such a way that the membership functions of the fuzzy sets in fuzzy partitions of the universes are changed from triangle waves into rectangle waves so that the basis variables in the universes disappear in the original nonlinear equation. However, the linearization models are incomplete in their forms because they lack some items. For solving this problem, joint approximation by using linear models is introduced. The simulation results show that marginal linearization models are of higher approximation precision than their original nonlinear models.