永磁同步电动机中基于冲洗滤波技术的混沌控制研究

针对永磁同步电动机中存在的混沌运动,给出了一种基于冲洗滤波（washout filter）技术的永磁同步电动机混沌控制方法.该方法以永磁同步电动机的电流作反馈,实现了混沌运动的控制.该控制方法不影响原系统的参数,只需要调整滤波器的控制参数,算法简单、易于工程实现.数值仿真结果表明了该方法的有效性和鲁棒性. 关键词： 冲洗滤波器 永磁同步电动机 混沌控制     

基于粒子群算法和OGY方法的混沌系统混合控制

利用引导混沌轨道的基本原理,将模拟鸟群寻食过程的粒子群算法用于混沌控制,提出了基于粒子群算法引导混沌轨道的新方法,在此基础上利用混沌参数小扰动控制方法（OGY方法）,把混沌系统稳定到不动点.以Hnon混沌系统为例,仿真表明此方法实现混沌控制有良好效果. 关键词： 混沌控制 粒子群算法 OGY控制 引导轨道     

受扰航天器姿态动力学中参数未知的混沌运动控制

研究了扰动力矩作用下航天器姿态运动的欧拉动力学方程. 讨论了当选取扰动力矩中不同的参数矩阵, 欧拉方程可产生一大类混沌系统. 设计了基于Lyapunov方法的自适应控制律, 完成了该类系统中参数未知的混沌运动的控制, 并且能够将系统状态变量稳定于指定平衡点, 同时实现了对未知参数的实时辨识. 以Newton-Leipnik系统为例, 进行了数值仿真, 仿真结果表明了该方法的有效性. 关键词： 姿态运动 混沌控制 参数未知 Newton-Leipnik 系统     

带未知扰动的多涡卷混沌系统修正函数时滞投影同步

研究了带有未知外部扰动的不同多涡卷混沌系统修正函数时滞投影同步问题. 基于Lyapunov稳定性理论, 采用模糊自适应控制的方法设计自适应同步控制器及参数的更新规则. 该控制器在实现混沌系统修正函数时滞投影同步的同时对外界扰动的变化能保持较好的稳定性. 数值仿真的结果进一步验证了该方法的有效性.     

非线性系统混沌运动的神经网络控制

设计前馈反传神经网络控制非线性系统混沌运动的新方法.根据扰动参数模型输入输出数据,按照非线性学习算法训练网络产生系统稳定所需的小扰动控制信号,去镇定混沌运动,使嵌入在混沌吸引子中的不稳定周期轨道回到稳定不动点上.Hnon映射数值仿真结果表明,这种方法控制非线性混沌系统响应速度快、控制精度高 关键词： 混沌控制 神经网络 吸引子 非线性     

基于Weiner模型超混沌lü系统的自适应辨识

为了能实时而有效地辨识参数不确定的超混沌lü系统,以便于对该系统进行控制或跟踪,本文提出了一种基于Wiener模型自适应分段线性(PWL)滤波器的超混沌系统辨识方法.Wiener模型的线性部分采用了线性横向滤波器,非线性部分用分段线性滤波器近似表示.根据最小均方误差准则导出了滤波器参数更新算法,并进一步推导出算法的收敛性条件.计算机仿真证实了该自适应滤波器辨识超混沌系统的有效性.该方法不仅克服了自适应线性滤波器难以辨识出这类强非线性系统,而且比其他非线性自适应滤波器的计算复杂性低得多.     

单周期控制Boost变换器Hopf分岔控制及电路实现

用平均模型分析了单周期控制Boost变换器的运行,分析表明在参考电压变化的情况下,单周期控制Boost变换器会出现Hopf分岔.Hopf分岔使得变换效率下降,器件应力增加.为了消除Hopf分岔,提出了采用washout滤波器的方法.建立了采用washout滤波器的单周期控制Boost变换器平均模型,对于washout滤波器中的两个新参数,可以用Routh-Hurwitz准则来确定.仿真和电路实验验证了所提方法的效果. 关键词： washout滤波器 单周期控制 Boost变换器 Hopf分岔     

受扰统一混沌系统的主动自适应模糊积分滑模控制

针对受扰统一混沌系统,提出一种主动白适应模糊积分滑模控制方法．在保持原非线性积分滑模控制暂态性能的同时,设计了一种改进非线性积分滑模控制方法,保证了系统的稳定性．所提出控制方法减小了统一混沌系统的不可控状态和自适应模糊补偿项的逼近精度对系统状态误差的影响．基于Lyapunov稳定性理论分析了系统的稳定性．数值仿真结果表明,在存在参数摄动和外部扰动时,能将统一混沌系统控制到目标点上．数值仿真验证了所提出控制方法的有效性．     

混沌系统的遗传神经网络控制

提出遗传神经网络控制混沌新方法.将小扰动技术和周期控制技术结合起来，用遗传算法训练神经网络，使之成为混沌控制器.对Henon映射和Logistic映射的仿真结果说明控制器能产生小扰动控制序列信号，将混沌振荡转变成规则运动状态.该方法无需了解动态系统数学模型，具有一定抗噪声干扰能力，可将它推广应用到其他混沌系统的控制中. 关键词： 遗传算法 神经网络 混沌 周期控制     

参数共振微扰法在Boost变换器混沌控制中的实现及其优化

参数共振微扰法是一种简单的非反馈混沌控制方法，它十分适合非自治系统的混沌控制.研究了这种方法在电流模式控制Boost变换器混沌控制中的应用，并通过对扰动相位进行优化 ，达到最优的混沌控制结果.同时对参数共振微扰法及其优化方法在Boost变换器混沌控制中的作用进行了理论分析，推导并计算了各种电路参数变化对有效的混沌控制所需的扰动的影响. 关键词： Boost变换器 混沌 混沌控制 参数共振微扰法     

Robust adaptive synchronization for a general class of uncertain chaotic systems with application to Chua's circuit

The synchronization problem for a general class of uncertain chaotic systems is addressed. The underlying systems may be perturbed by unknown time-varying parameters, unstructured uncertainties, and external disturbances. Meanwhile, the time-varying parameters and disturbances are neither required to be periodic nor to have known bounds. Assuming the disturbances are L(2) signals, an adaptive control incorporated with H(∞) control technique is employed to construct a robust adaptive synchronization algorithm. Then, removing such assumption, a novel adaptive-based method is developed to achieve the goal of synchronization. In order to demonstrate the effectiveness of the proposed algorithms, such methods are applied to solve the synchronization problem of uncertain chaotic Chua's circuits.     

一类带有未知参数的受扰混沌系统的观测器同步

在系统参数未知的情形下,观测器方法和自适应方法相结合,实现了一类受扰混沌系统的同步.借助于Lyapunov稳定性理论和Barbalat引理,给出了观测器的设计方法.此方法约束条件较少,适应于大部分常见的混沌系统.最后,通过对典型混沌系统的同步数值仿真,证实了方法的有效性和正确性. 关键词： 混沌系统 外界干扰 同步 观测器法     

Chaotic rotations of a liquid-filled solid

The disturbed Hamiltonian equations of a solid filled with a rotating ellipsoidal mass of a liquid and subjected to small-applied moments are revisited using Deprit's variables. We investigate the chaotic dynamics of the orbiting liquid-filled solid and of the liquid-filled solid sliding and rolling on a perfectly smooth plane, in either energy-conservative or energy-dissipative conditions, when appropriately perturbed. Criteria for the judgment of potential chaotic rotations of the perturbed system are formulated by means of Melnikov-Holmes-Marsden (MHM) integrals. Strategies for the solution of heteroclinic orbits of the symmetrical liquid-filled solid under torque-free conditions are outlined theoretically. Physical parameters that will probably trigger the onset of chaotic motions can be determined accordingly. Results from MHM algorithms are crosschecked with Poincare sections together with Lyapunov characteristic exponents.     

Impulsive control of chaotic systems with exogenous perturbations

The impulsive control of chaotic systems, which are subjected to unbounded exogenous perturbations, is considered. By using the theory of impulsive differential equation together with the fuzzy control technique, the authors propose an impulsive robust chaos controlling criterion expressed as linear matrix inequalities (LMIs). Based on the proposed control criterion, the procedure for designing impulsive controllers of common (perturbed) chaotic systems is provided. Finally, a numerical example is given to demonstrate the obtained theoretical result.     

USING RANDOM PROPORTIONAL PULSE FEEDBACK OF SYSTEM VARIABLES TO CONTROL CHAOS AND HYPERCHAOS

A method that allows one to control chaotic and hyperchaotic systems by a random proportional pulse feedback of system variables is proposed. This method is illustrated with the Rossler chaotic and the complex Lorenz-Harken hyperchaotic systems, and a better control result is obtained. The advantage of this method is that just one perturbed system variable is enough to obtain a stabilized periodic orbit.     

Stochastic resonance in chaotic systems

The phenomenon of stochastic resonance (SR) is investigated for chaotic systems perturbed by white noise and a harmonic force. The bistable discrete map and the Lorenz system are considered as models. It is shown that SR in chaotic systems can be realized via both parameter variation (in the absence of noise) and by variation of the noise intensity with fixed values of the other parameters.     

基于积分观测器实现一类受扰混沌系统的同步

在系统参数和系统输出同时受扰的情形下,基于积分观测器的方法,实现了一类不确定混沌系统的同步.首先利用Lyapunov 稳定性理论,给出了混沌系统同步所需的充分条件,此条件可以快速地实现驱动系统与响应系统的同步,然后结合Schur补定理,将此条件转化为求解线性矩阵不等式组.最后,借助Matlab软件包中的LMI工具箱,通过对受扰MLC电路系统的同步数值仿真,证实了该方法的有效性.     

Ionisation of metastable 3P-state hydrogen atom by electron with exchange effects

Propagation of nonlinear shock waves for the generalised Oskolkov equation and dynamic motions of the perturbed Oskolkov equation are investigated. Employing the unified method, a collection of exact shock wave solutions for the generalised Oskolkov equations is presented. Collocation finite element method is applied to the generalised Oskolkov equation for checking the accuracy of the proposed method by two test problems including the motion of shock wave and evolution of waves with Gaussian and undular bore initial conditions. Considering an external periodic perturbation, the dynamic motions of the perturbed generalised Oskolkov equation are studied depending on the system parameters with the help of phase portrait and time series plot. The perturbed generalised Oskolkov equation exhibits period-3, quasiperiodic and chaotic motions for some special values of the system parameters, whereas the generalised Oskolkov equation presents shock waves in the absence of external periodic perturbation.     

Chaotic Dynamics of a Periodically Modulated Josephson Junction

We study the chaotic dynamics of a periodically modulated Josephson junction with damping. The general solution of the first-order perturbed equation is constructed by using the direct perturbation technique. It is theoretically found that the boundedness conditions of the general solution contain the Melnikov chaotic criterion. When the perturbation conditions cannot be satisfied, numerical simulations demonstrate that the system can step into chaos through a period doubling route with the increase of the amplitude of the modulating term. Regulating specific parameters can effectively suppress the chaos.     

基于无模型方法的混沌系统自适应控制

传统的混沌控制方法大多需要获知混沌系统的模型知识, 但是工业实际中系统的参数经常是未知的,与此同时系统建模过程当中经常会不可避免地存在未建模的动态不确定性, 这种情况下常规的混沌控制方法不能取得优化的控制性能指标．为解决此问题, 提出了一类基于无模型方法的混沌系统自适应控制算法．该算法基于数据驱动, 无需混沌系统的先验知识, 无需训练过程, 在线调整参数较少, 是一种低成本的控制器．数学证明了该控制系统的稳定性, 仿真结果说明了这种理论的有效性． 关键词： 混沌控制 自适应 无模型 数据驱动