COMPOSITE MODEL REFERENCE ADAPTIVE CONTROL FOR A CLASS OF NONLINEAR FRACTIONAL ORDER SYSTEMS

This article presents a novel model reference adaptive control of fractional order nonlinear systems, which is a generalization of existing method for integer order systems. The formulating adaptive law is in terms of both tracking and prediction errors, whereas existing methods only depends on tracking error. The transient performance of the closed-loop systems with the proposed control strategy improves in the sense of generating smooth system output. The stability and tracking convergence of the resulting closed-loop system are analyzed via the indirect Lyapunov method. Meanwhile, the proposed controller is implemented by employing some fractional order tracking differentia tor to generate the required fractional derivatives of a signal. Numerical examples are provided to illustrate the effectiveness of our results.