【作者】 何宴辉；

【导师】 关新平；

【作者基本信息】 燕山大学 ， 控制理论与控制工程， 2003， 硕士

【摘要】 对混沌现象的研究是非线性科学中重要课题之一，混沌运动是一种确定性的类随机运动，它广泛存在于客观世界中，由于混沌的奇异特性，不施加控制的混沌将无法应用，混沌控制是混沌走向应用的第一步，因此混沌系统控制与应用的研究成为非线性科学的研究热点。本课题沿着混沌控制(狭义)和混沌同步为主线在国家自然科学基金“时滞混沌系统的控制和同步研究” 和河北省自然科学基金“混沌保密通信技术及应用研究”的资助下主要研究了以下几方面的内容：(1)运用Backstepping方法对含有不确定性的严格反馈混沌系统进行控制，分别基于连续函数补偿和RBF神经网络补偿取得了较好的控制效果。基于特殊的滑模控制方法结合参数辨识对含有未知参数的统一混沌系统实现了不稳定不动点的跟踪控制。(2)研究了扰动情况下混沌系统的恒等同步与线性广义同步问题，首先利用线性变换对混沌系统进行扰动解耦，使得受扰动部分可用未受扰部分和系统输出来表示，然后利用两种非线性观测器重构混沌系统实现恒等同步。同时借鉴线性系统中含有未知输入的观测器设计方法，将扰动看作是未知输入实现了时滞混沌系统的线性广义同步。(3)首次提出了弹性同步的概念。考虑到不只混沌系统自身会受到扰动或不确定性的影响，而且控制器在很多情况下也不能精确实现，存在一定程度的摄动，其对同步产生的影响有时是巨大的，为此在摄动界已知和未知两种情况下分别给出了弹性同步控制器的增益形式。(4)研究了混沌在保密通信领域的应用问题，基于VC++编写了加密软件实现对图像文件的加密，软件采用混沌遮掩与混沌置乱两级加密原则，具有执行速度快，加密程度高等优点。更多还原

【Abstract】 Research on chaos is one of the important achievements in nonlinear science. Chaotic motion is a complex motion, whose equation is certain but the trajectory of the orbits is stochastic. There are lots of chaotic phenomena in real world. For oddities of chaos, uncontrolled chaos will not be applied, so chaos control is the first step of chaos application. Chaos control and cha0os application have already become hot field in nonlinear science.This project is supported by National Science Foundation of China and Hebei Science Foundation. Along the chaos control(narrow sense) and chaos synchronization, the main results of this thesis are expressed as follows: (1)By backstepping method, the strict-feedback chaotic system with uncertainties was stabilized, in which we applied continuous function and RBF neural network to compensate the uncertainties. The control aim was realized. Based on special sliding-mode control with parameter identification, the unified chaos was led to unstable equilibrium point.(2)Chaos identical synchronization and linear generalized synchronization was studied. Firstly we divided the chaos with perturbation into two parts, furthermore denoted the perturbed part by unperturbed part and output. Secondly by two nonlinear observers we realized the chaos identical synchronization. At the same time, according to unknown input linear observer, the linear generalized synchronization controller was designed.(3)For the first time, the resilient synchronization was put forward. The uncertainties or perturbation not only exist in chaos itself but also in controller, namely the controller can’t be implemented exactly, which may be deadly to synchronization. To solve the problem, we design the resilient controller under known and unknown disturbed bound.(4)Chaos application in secure communication was introduced. Based <WP=6>on VC++, we developed image encryption software, in which chaos masking and chaos image permutation was adopted. Simulation results showed that the software implemented quickly and encrypted highly.更多还原