A Novel Adaptive Fuzzy Control Scheme for a Class of Nonlinear Planar Systems Under State Constraints

The adaptive fuzzy control method has been widely used in the control of nonlinear systems. The system state is required to stay in a compact set for the effectiveness of the fuzzy logic system approximation. Therefore, many control schemes integrating adaptive fuzzy control and full-state constraint control techniques have been proposed for nonlinear systems. In this brief, a novel adaptive fuzzy controller is developed for a class of nonlinear planar systems. The system state is required to satisfy the specific constraints which are first proposed in this brief. It is strictly proved that the control scheme can make the system state asymptotically converge to the origin (not merely the neighborhood of the origin) and guarantee that the specified state constraints are not violated. In addition, the restriction on the rated constraint boundaries of different state components is explicitly given, which guarantees that the feasibility condition is naturally satisfied. Finally, the developed control scheme is applied to a specified PMSM system to show its effectiveness.