On Finite Time Chaotic Synchronization Based On SMC

Chaos theory is the scientific revolution in recent four decades. Chaotic system is a typical, overall stability, internal random and highly uncertain nonlinear system, which exists in nature widely. Chaos has periodic, continuous broadband spectrum, similar to the noise, initial sensitivity and other characteristics, which make it has research value and attractive prospect in secure communication. Synchronization is the core technology of chaotic secure communication, with the gradual chaos synchronization technology, conventional control strategies and algorithms. Such as linear feedback method, the direct construction method; active-passive control law cannot meet the confidentiality of communications control requirements. Synchronization of chaotic systems in the dynamic quality of each phase, the speed and robustness is particularly important. Since sliding mode control for the system parameter perturbation and external disturbance term has a strong robustness, through the design of sliding mode to obtain a satisfactory dynamic quality. Then chaotic synchronous controller is designed by useing sliding mode control theory.This paper considers the system disturbance were matched uncertainties and mismatched uncertainties cases. The matched uncertainties assumptions norm bounded uncertainty, design sliding mode controller to meet the stability analysis Conditions, the stability proof is given. For the mismatched uncertainty, LMI-based design of sliding mode controller gives proof of stability, numerical simulation and analysis of results.Conventional linear sliding mode control can make the system asymptotically stable, but the time to reach equilibrium often cannot guarantee a finite time. Such a requirement for synchronization errors reach to zero in the finite time, linear slide mold surface shows some limitations. In order to improve the speed and robustness, this paper solve the problem that terminal sliding mode control may exist singular phenomenon, considering the uncertainty on the system parameters of the known boundary conditions designed controller, and gives the stability proof. Sliding mode control with linear simulation comparison shows Terminal sliding mode finite time convergence characteristics.Since the application system, the system uncertain parameters are often difficult to measure, so that the uncertainty parameters are not sure. Therefore, this paper considers the unknown of the uncertainty function on the boundary, online identification system, useing adaptive method of parameter uncertainty, has been designed for terminal sliding mode variable structure adaptive controller, and the stability of system has been proved. Through the chaos synchronization is applicated in secure communication systems, and the effectiveness of the controller has been proved.Finally, the main contents of this paper are summarized, and future research directions were discussed.