| The more and more people pay close attention to the information security. Chaotic system can apply to secure communication because chaos signal has noise-like property. Based on the theories of nonlinear control and stability analysis, for the uncertain chaotic systems, the chaotic systems of uncertain parameters, the chaotic systems with diverse structures, this dissertation studies several kinds of synchronous ways and the application in secure communication. The main contributions of this dissertation are as follow:Firstly, the active control and the pinning control method are proposed to achieve the synchronization of two uncertain chaotic systems with parameters perturbation. The results indicate the controller can synchronize uncertain Lorenz chaotic systems with excellent robust stability, and the controller is simper.Secondly, according to the strategy of adaptive control for parameters and the feedback control method, for the uncertain parameters of system, the adaptive controller is designed, which realizes the synchronization of Lorenz chaotic systems. The method can realize monotonous synchronization and identify the uncertain parameters quickly.Thirdly, for chaotic systems with diverse structures, based on Lyapunov stability theory, a nonlinear feedback controller is presented, and the synchronization between Lorenz system and Lii system is achieved, the effect is good. The method makes the synchronization of different structures systems become possible and the research of uncertain chaotic system have universal way.Finally, based on the method of chaos parameter modulation and nonlinear filtering theories, secure communication of self-adapting parameter modulation and diverse structures parameter nodulation is realized successfully for theoretical analysis and numerical simulation, having strong security and practicability. |
