Adaptive backstepping output feedback control for a class of nonlinear fractional order systems

This article presents a novel fractional order adaptive backstepping output feedback control scheme for nonlinear fractional order systems. The needed feedback information is constructed via a state estimation filter. To improve the control performance, tracking differentiators, nonlinear elements and fractional order update laws were introduced and applied to the control systems. With the aids of this frequency distribute model and the indirect Lyapunov method, the stability and the tracking convergence of the resulting closed-loop system were established. A careful simulation study was provided to illustrate the effectiveness of this novel scheme.