Decoupled adaptive fuzzy sliding-mode control

We propose 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, where each subsystem has a separate control purpose expressed in terms of a sliding surface. Then, using the information from the secondary target conditions, the main target generates a control action to make both subsystems move toward their sliding surfaces, respectively. Two sets of fuzzy rule bases are utilized to represent the equivalent control input with unknown system functions of the main target. The membership functions of the THEN-part, which is used to construct a suitable equivalent control of SMC (sliding mode control), are changed according to the adaptive law.