Adaptive time-delay synchronization of chaotic systems with uncertainties using a nonlinear feedback coupling

Abstract

This paper treats the adaptive synchronization problem of a class of uncertain chaotic systems with uncertainties, delay and unknown inputs in a drive-response framework. A robust adaptive observer-based response system is designed to synchronize a given delayed chaotic system without the knowledge of upper bounds of uncertainties and unknown inputs. Furthermore, the unknown inputs can be approximately recovered directly by the concept of equivalent control signal. To highlight our method, we improve the robustness of ciphering in a secure communication system. Computer simulation is also given for the purpose of illustration and verification.