Research On Synchronization Of Chaotic Systems And Secure Communication

Chaos is represented by a definite nonlinear dynamic system, and its behavior is inherent randomness. Synchronization control and its application in the nonlinear field has become the fascinating study since Pecora and Carroll put forward the principle and the chaos synchronization can be realized in the circuit in 1990. In particular, the secure communication based on chaos synchronization has gained more attention. The main content in this paper are as follows:Firstly, for different structure chaotic systems, an active controller based on active control and Lyapunov stability theory is designed to synchronize two different structure chaotic systems. Based on chaotic masking and chaotic parameter modulation, utilized the two synchronized systems, the communication systems are set up. And the simulation results show that, the useful signal can be recovered from the receiver effectively.Secondly, in unified chaotic systems, a nonlinear function based on Lyapunov stability theory in the response system, and a system parameter adaptive rate and proper controller are used to ensure synchronization between the response chaotic system and any drive system with parameter switching in finite time. In chaotic masking secure communication system which is based on unified chaotic systems with different parameters, the useful signal can be recovered from the receiver effectively; the system parameter of drive system can switch randomly in the effect of parameter adaptive rate, therefore, the sending system can change any time, which is helpful to the decode difficulty. In addition, system security has been strengthened by the conversion functions of useful signal.Thirdly, for uncertain chaotic systems, based on active control and virtual feedback control strategies, a novel active sliding mode controller is presented, which can make the uncertain Chen chaotic systems realize synchronization in finite time.Finally, a sliding mode observer-based response system is designed to synchronize with a given uncertain chaotic drive system with signal, a sliding mode control law is given to synchronize the uncertain chaotic system and synchronization is asymptotically stable. The concept of equivalent control is used to recover useful signal, and the simulation results show the method is effective in the uncertain Genesio chaotic systems, and the useful signal can be recovered.