Adaptive synchronization of chaotic systems via state and measured-output feedback controls 1

In this paper, the problem of robust adaptive control for synchronization of coupled continuous-time chaotic systems, probably subject to disturbances, is discussed. A general model is studied via different approaches using either state-feedback or output-feedback controls. Adaptive controllers are designed, in which a sliding mode structure is employed to increase the robustness of the closed-loop systems. When only system output but not the system state is measurable for synchronization, the adaptive controllers are designed by incorporating with a filter and using the so-called σ -modification technique. Several numerical examples are included to demonstrate the effectiveness of the proposed chaos synchronization methods.