| Chaos looks like a random movement, it is a unique form of motion which belongs to nonlinear dynamical system and widely exists in nature. Since1980s, the means of controlling chaotic synchronization has become an important topic and it has been widely applied in secure communication, artificial intelligence and so on. However, chaotic circuit has not been researched as same as the theory of chaos, and the theory is far away from application. In this paper, circuits of controller and chaos are designed to achieve chaotic synchronization and secure communication based on theoretical analysis and software simulation, the relationship between theory and application is enhanced. The main works are as follows:The transformation is applied to Lorenz system, the validity and necessity of that transformation is verified by Matlab simulation. Secondly, the Lorenz circuit is designed according to the result of Multisim simulation and the circuit of Lorenz system is build with electronic components. Finally, the circuits of several controllers are designed to achieve synchronization of Lorenz chaotic system based on PC, series-wound and passive-active. The validity of these controllers is proved by Multisim simulation.The controller based on single-variable feedback is designed in order to achieve synchronization of Lorenz chaotic system, this controller can ensure the asymptotic stability of error system by Lyapunov method and the range of the control gain can be gotten. The circuit of this controller is designed and completed based on the result of Multisim simulation. Secondly, it is applied to voice chaotic secure communication based on chaotic masking. Finally, an improved program is designed to strengthen the security and be more practical, the improved program can be proved and completed by Lyapunov method, Matlab simulation, Multisim simulation and building circuits.Analog chaotic signal is used to carry useful signal, and a delay synchronization controller based on the delay exists between the signals passed by wireless module is designed, this controller can ensure the asymptotic stability of error system by Lyapunov method, and then the validity of this controller is verified by Matlab simulation, the realizability of this controller is verified by Multisim simulation. Finally, the wireless voice chaotic secure communication is achieved by choosing FM radio module and building the circuit. |
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