분리된 비선형 시스템의 적응 퍼지 슬라이딩모드 제어

Abstract

We proposed a decoupled adaptive fuzzy sliding-mode control scheme for a class of fourth-order nonlinear systems. The system is decoupled into two second-order systems such that each system has a seperate control target expressed in terms of sliding surface. For these sliding surfaces, we define amin and sub target conditions. And, we made intermediate variables which are interconnected both surface conditions from the sub target sliding surface. Then, two sets of fuzzy rule bases are utilized to represent the equivalent control input with unknown system functions of the main target sliding surface including intermediate variables. The membership functions of the THEN_part, which is used to construct a suitable equivalent control of sliding-control, are changed according to the adaptive law. With such a design scheme, we not only maintain the distribution of membership functions over state space but also reduce the computing time considerably. We apply the coupled adaptive sliding-mode control to a nonlinear Cart-Pole system and confirms the validity of the proposed approach.