Adaptive backstepping fuzzy synchronization control of fractional-order chaotic systems with input saturation and external disturbances

Abstract

In this paper, an adaptive backstepping command filtered controller is proposed for a class of uncertain strict feedback fractional-order chaotic systems with input saturation and external disturbances. A command filter is designed to avoid the “explosion of complexity” problem in the conventional backstepping technique. To tackle with filter error and improve synchronization accuracy, a compensation mechanism is provided. Meanwhile, fuzzy logic systems are utilized to approximate unknown functions, and disturbance observers are constructed to reduce the impact of unknown disturbances. In particular, to reduce the chattering phenomenon, a smooth function rather than the sign function is used in the controller design, and the stability of the closed-loop system can be guaranteed by the proposed synchronization controller. A simulation study is provided to confirm the practicality and validity of the proposed method.