Direct adaptive fuzzy control for nonlinear systems with input amplitude and rate saturation constraints

This paper presents a direct adaptive fuzzy control scheme for a class of uncertain single-input single-output nonlinear systems subject to input amplitude and rate saturation constraints. The fuzzy controller is designed to mimic an ideal controller which is assumed guarantying the control objective. The free parameters of the fuzzy controller are adjusted by an adaptive law which prevents the presence of input constraints from degrading the closed-loop system stability. The stability properties of the proposed adaptive controller are obtained via Lyapunov analysis. A numerical simulation example is given to demonstrate the effectiveness of the proposed adaptive control approach.