基于条件李亚普诺夫指数的混沌系统的脉冲同步研究

基于条件李亚普诺夫指数,对混沌系统的脉冲同步形式和同步范围进行了研究,突破了传统的基本假设．计算机仿真证明了该方法的有效性和正确性．此外,作为该方法的重要基础,本文给出脉冲同步系统的条件李亚普诺夫指数计算方法．     

一类非自治混沌系统的自适应脉冲同步

研究了一类具有未知Lipschitz常数的非自治混沌系统的自适应脉冲同步问题.首先基于Lyapunov稳定性理论、自适应控制理论及脉冲控制理论设计了自适应控制器、脉冲控制器及参数自适应律,然后利用推广的Barbalat引理,理论证明响应系统与驱动系统全局渐近同步,并给出了相应的充分条件.两个数值仿真例子表明本方法的有效性.     

脉冲无线电通信系统的正交锁相环路同步方法

使用正交模拟锁相环路对无栽渡的脉冲无线电系统实现多径捕获和同步提取。首先给出脉冲信号在正交正弦信号分解的结果特性，得出锁相接收的可能性。然后给出了使用正交模拟锁相环路实现多径捕获和同步提取的方法和步骤，讨论了锁相环路的性能和关键参数，给出了在实际信道数据下的模拟结果。结果表明该方法优于现有的多径捕获和同步方法，且结构简单易于实现。     

一种有源滤波抗干扰同步信号电路

给出一种利用二阶有源滤波电路和比较器构成的同步脉冲与同步方波产生电路,进行了适当的理论分析,给出了具体设计方法和应用实例.     

基于脉冲同步的混沌系统自适应参数估计

针对一类参数不确定混沌系统,提出了一种基于脉冲同步的自适应参数估计方法,给出了脉冲控制增益和参数自适应律的解析表达式,从理论上证明了该方法可以准确估计出参数不确定混沌系统的所有未知参数.以Lorenz混沌和Ueda振荡器系统为例,数值模拟证明了该方法的有效性.     

基于脉冲同步的混沌保密通信系统

介绍了脉冲混沌同步的基本原理,提出了基于脉冲同步的一般化混沌保密通信系统。针对该系统存在的传输时间帧拥堵问题,提出一种“信息感应”脉冲同步系统。该系统中有用信息被嵌入在发射端的同步脉冲里,在接收端再通过这些脉冲被感应出来,解决了时间帧拥堵的问题。     

基于FPGA的GPS同步时钟装置的设计

在介绍了GPS同步时钟基本原理和FPGA特点的基础上,提出了一种基于FPGA的GPS同步时钟装置的设计方案,实现了高精度同步时间信号和同步脉冲的输出,以及GPS失步后秒脉冲的平滑切换,给出了详细设计过程和时序仿真结果。     

随机Lur’e时滞网络的指数同步与脉冲控制

本文研究了一类具有不对称耦合和时变时滞随机Lur’e动态网络的全局指数同步问题. 为了使网络中的所 有Lur’e系统达到同步, 文章提出了一种实用的脉冲控制策略, 利用平均脉冲间隔概念、Perron-Frobenius定理、比较 原理、参数变分法和无参照系统策略, 给出了保证网络实现全局指数同步的充分条件. 基于脉冲信号既能促进网络 群聚行为同时也可能阻碍网络同步这一事实, 本文分别讨论了积极脉冲效应和消极脉冲效应作用下网络实现同步 的判定方法, 同时给出了不同脉冲效应作用下网络的收敛速度. 提供了数值仿真证明主要结果和控制策略的有效 性.     

一个混沌系统的同步控制研究

研究了一个混沌系统的混沌同步控制问题。分别采用线性反馈控制方法、非线性反馈方法、脉冲控制方法对该混沌系统进行同步控制。基于Lyapunov稳定性理论和脉冲控制技术,对同步的充分条件进行了讨论,并给出了相应的理论证明。数值仿真证明了这三种不同方法的有效性。     

ADSL在线测试系统的同步方法研究

在ADSL在线测试系统设计中，接收器的同步问题是设计的难点之一。本文论述了ADSL在线测试系统的三种同步技术（采样同步，帧同步和超帧同步），对同步算法进行了理论分析，并给出了基于FPGA硬件的同步实现方案。     

Impulsively synchronizing chaotic systems with delay and applications to secure communication

In this paper, the presence of transmission delay and sampling delay in chaos-based secure communication systems by employing impulsive synchronization is studied. A time delayed impulsive differential system with delayed impulses, modeling the synchronization error between the driving and response schemes employed in such communication systems, is presented. The equi-attractivity property of the error dynamics is investigated and the sufficient conditions leading to this property are obtained. A set of upper bounds on the delay terms involved in the system are also obtained, and a numerical example is given. A communication security scheme employing hyperchaotic systems possessing continuous driving, impulsive driving and delay is proposed and simulation results are given to demonstrate the performance of the scheme.     

Stochastic synchronization of delayed multiagent networks with intermittent communications: An impulsive framework

This paper investigates the stochastic synchronization problem of delayed multiagent networks with intermittent communications. Two kinds of impulsive effects are taken into account, ie, impulsive controller (positive impulsive effect) and impulsive disturbance (negative impulsive effect). Impulsive controller allows the synchronization to be realized and requires only state information exchange at discrete time instants such that the communication cost of bandwidth is reduced. Meanwhile, impulsive disturbance is inevitable in most of practical systems and therefore is taken into consideration at discrete time instants. Sufficient conditions for synchronization are given in terms of the graph topology, the control coupling gains, and the individual agent dynamics parameters, which indicates that synchronization can be realized if the impulsive effects coefficients and communication rate are suitably selected. Simulation results verify the effectiveness of the proposed synchronization protocol.     

Exponential synchronization of impulsive complex networks with output coupling

This paper proposes a new impulsive complex delayed dynamical network model with output coupling, which is totally different from some existing network models. Then, by employing impulsive delay differential inequalities, some sufficient conditions are obtained to guarantee the global exponential state synchronization and output synchronization of the impulsive complex delayed dynamical network. Finally, two numerical examples are given to demonstrate the effectiveness of the obtained results.     

复杂网络的脉冲同步

研究了具有有界耦合函数的不确定复杂动态网络的脉冲同步问题．根据脉冲控制的概念和脉冲微分方程的稳定性理论,我们利用一个灵活有效的脉冲控制实现了复杂动态网络的脉冲同步．最后,通过对混沌系统做网络节点的动态网络的数字模拟,验证了我们提出的脉冲控制方案的有效性和实用性．     

Asymptotical Synchronization of Coupled Nonlinear Partial Differential Systems With Impulsive Effects

This paper considers the asymptotical synchronization of coupled nonlinear impulsive partial differential systems (PDSs) in complex networks. The cases of both complex networks with fixed topology and switching topology are studied. Based on the Lyapunov–Krasoviskii functional method, sufficient conditions are presented to guarantee the asymptotical synchronization of nonlinear impulsive PDSs, under the cases of fixed topology or switching topology. The effect of the spatial domain is exhibited in these sufficient conditions. Moreover, these sufficient conditions provide a method for selecting a suitable impulsive strategy for the coupled PDSs to achieve the asymptotical synchronization. Finally, numerical examples are given to illustrate the correctness.     

Uniform stability of discrete impulsive systems

This article studies discrete impulsive systems. The uniform stability (uniformly asymptotic stability and quasi-exponential stability) criteria are established for linear discrete impulsive system and a class of nonlinear discrete impulsive systems, respectively. These stability criteria are expressed in terms of fairly simple algebraic conditions so that they are easy to be tested. Moreover, by using the stability criteria, a discrete impulsive synchronization scheme is designed to synchronize two discrete chaotic systems. Finally, some examples are given to illustrate results obtained by us.     

Synchronization of singular switched complex networks via impulsive control with all nonsynchronized subnetworks

This paper studies impulsive synchronization of a class of nonlinear singular switched complex networks (SSCNs). With the aid of discretized Lyapunov function method and the matrix generalized inverse technique, an impulsive controller is designed, which works on both the slow and the fast state variables to synchronize SSCNs at impulsive instant. Based on the designed controller, it is shown that the synchronization of SSCNs is achieved in two cases: all subnetworks that are not self‐synchronized and all subnetworks that are self‐synchronized. Moreover, an example is given to validate the effectiveness of the proposed controller.     

具有信道时延的混沌神经网络脉冲同步

由于控制脉冲只是在特定的时间序列产生,使得同步系统中所需的驱动系统信息和能量减少,从而给混沌系统同步设计带来巨大方便。但是,由于实际电路中器件的切换速度有限且内在通讯需要时间。在通信网络中将不可避免地产生时延。因此,现有的一些同步方法将无法实现。针对这种情况,提出了一种基于脉冲控制的混沌神经网络同步策略。在该策略中考虑了信道时延带来的影响,并设计了控制器实现两个混沌神经网络的同步。计算机仿真结果验证了该方法的可行性和有效性。     

混沌协议同步技术研究

混沌数字保密通信实现的关键是混沌严格同步技术。该文以网络混沌语音保密通信系统为平台,从网络通信协议的思路出发,在混沌脉冲同步理论及应用的启发下,提出并研究了混沌协议同步技术,解决了混沌数字保密通信的关键技术难题,对混沌协议同步技术进行了改进,形成了初步的协议同步机制。此技术可方便地嵌入到现有的通信系统中,提高其保密性,实用性很强。