Adaptive Control For Anti-synchronization Of Delayed Chaotic System And Its Application To Secure Communication

Since the chaotic system has been widely applied in various fields, the research aboutchaotic system has been developing in depth at home and abroad. The main concern in this thesisis the anti-synchronization of time-delayed chaotic systems and its application. Theanti-synchronization of a class of delayed hyperchaotic systems with uncertain parameters anddifferent structures is studied by using the adaptive method. A new control law is designed in thelight of Lyapunov theory of stability. The method is proved to be effective and valid by thetheoretical analysis and numerical simulation. Finally, the chaotic secure communication systemis constructed on the basis of the adaptive anti-synchronization method. The Matlab simulationresults show that the useful signal is recovered effectively at the receiving terminal.In chapter one, the related chaos theories are introduced which include the definition ofchaos, hyperchaos and the chaos phenomenon. There also introduce the current situation,development trend of chaos anti-synchronization and chaos synchronization in the securecommunication. In addition, the innovation and meaning of this study are illuminated. In chaptertwo, the principle and method of stability and the definition of synchronization andanti-synchronization are given. In chapter three, the anti-synchronization of Genesio system withcertain or uncertain parameters is studied. In order to realize the anti-synchronization of theGenesio chaotic systems, a new controller and the parameter adaptive rate are well designedaccording to stability theory and the adaptive control method. The anti-synchronization isachieved and the unknown parameters of the systems can be identified by the new approach. Theresults of the numerical simulation show that the method is effective and feasible. In chapter four,a new adaptive method is designed to solve the anti-synchronization problem of the two differentchaotic systems with uncertain parameters. A global method is put forward to realize theanti-synchronization and synchronization of the two different systems with different variables. Atlast, the simulation of anti-synchronization and synchronization of Chen and Lu Chaotic systemwith different delays show that the method is effective. In chapter five, depended on theanti-synchronization of the Hyperchaos, the secure communication system is constructed on thebasis of chaotic masking and the chaotic parameter modulation theory, which improve thesecurity properties of communication system. The simulate results show that the useful signal could be recovered effectively.