Research On Intelligent Control And Secure Communication Of Chaos Synchronization

This thesis is for the purpose of designing good-performanced chaos synchronization controller with intelligent control theory and method, and also studying the application of chaos synchronization to secure speech communication based on DSP. First of all, most existing methods of chaos synchronization through intelligent control as well as the development of secure communication through chaos synchronization are briefly analyzed, and the conclusion is made that most intelligent control methods used in chaos synchronization are based on slightly disturbed feedback control from the standpoint of control policy, and they can be sorted into several development trends.Based on this, an investigation is made into the application of genetic algorithm(GA), fuzzy control and T-S fuzzy model to chaos synchronization. GA is used to optimize parameters of a kind of synchronization controller, with its strong ability in parallel searching and a proper choice of adaptability function, optimized parameters can be found which greatly improve synchronization results. In order to overcome the difficulty of parameter-adjusting in Continuous Variable Feedback Synchronization (CVFS), the idea of fuzzifying its parameters is put forward. According to existing experience, a fuzzy controller is designed to change control parameters momentarily, which leads to a better result. T-S fuzzy model is used to describe chaotic systems, and error state equations of two chaotic systems of the same form can be deduced. Using parallel distributed compensation(PDC) to determine the structure of synchronization controller, the stability conditions of error system can boil down to a problem of Linear Matrix Inequality(LMI). In this way, a synchronization controller with simple structure and easy completion is obtained.Finally, a study of the application of chaos synchronization to secure speech communication based on DSP is carried out. Chaotic signal is pretreated in order to meet the requirements of masking speech signal, and a simplex system of secure speech communication is constructed with TMS320C5402 DSK provided by Texas Instruments. The software of sampling, encryption, transmission, decryption and broadcasting of speech signal is designed, meanwhile, the"timing compulsion synchronization"is presented to solve the...