Research On Fractional Chaotic Circuits With Multi Scrolls And Their Applications

The main topic of the present dissertation is the fractional multi-scroll and its application. Firstly, some basic knownlege of chaos and some basic methods of circuit design are introduced, which are used for future work.Fractional Chen system and fractional Liu system are introduced, and their circuit experiments are studied. At first, theoretical analysis and numerical simulation are done, and fractional unit circuit is designed by frequency domain approximation method. The values of the various components are given, and the circuit experiment is done. The phase diagram of circuit experiment keeps pace with the phase diagram of numerical simulation, which proves correctness of the circuit design and existence of fractional Chen system and fractional Liu system.An improved multi-scroll chaotic system is presented. According to the analysis of scattering character and equilibrium, there are 4 scrolls in the phase diagram of the improved multi-scroll chaotic system. The circuit is designed for the system according to its mathematical models. The values of the various components are given, and the circuit experiment is done. The result of numerical simulation and circuit experiment proves correctness of the circuit design and existence of the improved multi-scroll system exists. The fractional multi-scroll chaotic system and its circuit implementation are studied.There are 5 equilibrium points, which are 4 saddle points of index 2 and 1 saddle point of index. So it could exist 4 scrolls. According to the necessary stability condition for the fractional order system toremain chaotic, the range of order isα> 0.8528. And we get the phase digram of chaotic attractor whenαis 0.9 by MATLAB simulation. At last, the circuit experiment is done. The result proves the existence of the fractional multi-scroll system, and it could realized by circuit whenαis 0.9.In the end, the application of a improved chaotic circuit for secret communication is mainly studied. The system of chaos masking security communication is designed. And the new chaotic synchronous circuit is designed by using the feedback synchronized method. The results show new chaotic circuit could produce chaotic signal with complex chaotic phenomenon, which could improve the confidential performance. And we find the received signal exists power ebbing which is processed by modulation and demodulation. The reason is the loss of transmission channel, and it is inevitable.