新的三维自治混沌系统及其电路仿真

为了丰富非线性电路领域的研究内容,提出一个新的三维自治混沌系统,构造其数学模型。运用MATLAB对它的相图、Lyapunov指数、庞加莱映射图等复杂动力学特征进行分析研究,证实此三维混沌系统是一个新三维混沌自治系统。通过非线性电路的基本理论,将数学模型转化为电路方程,进而构造出符合该混沌系统的非线性电路,运用Muhisim软件对该电路进行仿真,验证了其真实存在性。     

新的三维自治混沌系统及其电路仿真

为了丰富非线性电路领域的研究内容,提出一个新的三维自治混沌系统,构造其数学模型.运用MATLAB对它的相图、Lyapunov指数、庞加莱映射图等复杂动力学特征进行分析研究,证实此三维混沌系统是一个新三维混沌自治系统.通过非线性电路的基本理论,将数学模型转化为电路方程,进而构造出符合该混沌系统的非线性电路,运用Multisim软件对该电路进行仿真,验证了其真实存在性.     

基于文氏振荡器的忆阻混沌电路

该文采用文氏桥振荡器和磁通控制的分段线性忆阻器,设计了一种新的单一参数控制的混沌电路。通过调节控制参数,该系统在忆阻器的非线性作用下,通过倍周期分岔产生了混沌和超混沌现象。利用常规的动力学分析手段研究了电路参数变化时系统的动力学特性,例如平衡点稳定性分析,李雅普诺夫指数谱和分岔图。为了验证电路的正确性,该文采用集成运放和压控开关实现了一个分段线性磁控忆阻器的模拟等效电路,并将该系统应用于提出的混沌电路,Pspice仿真结果与理论分析完全吻合。     

简洁无电感忆阻混沌电路及其特性

采用非理想有源电压控制忆阻器和磁通控制型光滑3次非线性忆阻器,该文设计了一种不含电感的简单(只含5个电子元器件)双忆阻混沌电路。采用常规的非线性分析手段详细研究了电路参数变化时系统的基本动力学行为,例如平衡点稳定性分析,相轨图以及李雅普诺夫指数谱和分岔图等。通过调节系统控制参数,该系统可产生多涡卷、多翼以及暂态混沌等十分丰富的动力学现象。此外,还研究了系统依赖于忆阻器初始状态的多稳态,得到了一些有意义的结果。为验证电路的可行性及稳定性,通过对忆阻器的模拟等效电路的搭建,并将该等效电路应用于所提出的混沌电路中,硬件电路实验结果以及Multisim电路仿真结果与理论分析一致。     

并联型忆阻器混沌电路设计

利用磁控忆阻器、电感和电容三个元件并联设计了一种新型忆阻器混沌电路。采用常规的动力学分析方法研究了系统的基本动力学特性,例如相图、平衡点稳定性分析、李雅普诺夫指数谱和分岔图。结果表明该系统产生了一类特殊混沌吸引子,且随系统参数改变,系统可以产生丰富的混沌行为。为验证电路混沌行为,利用Pspice进行了相应的电路仿真,仿真结果与理论分析、数值仿真基本一致。     

一种新型双忆阻混沌系统动力学及其电路实现研究

在经典的蔡氏混沌电路基础上,引入三次非线性磁控忆阻模型,利用一个磁控忆阻模型和一个荷控忆阻模型,外加一个负电导替换变形蔡氏电路中的蔡氏二极管,设计了一个五阶混沌电路,用常规的方法研究系统的基本动力学特性。通过数值仿真结果表明电路在参数变化情况下能产生Hopf分岔和反倍周期分岔两种分岔行为,并能产生双涡卷、单涡卷、极限环、同宿轨等不同轨道,出现了双单摆运动。观察混沌吸引子推广到功率与能量信号,观察到蝴蝶翅膀重叠的奇异吸引子。通过改变初始值,能产生共存吸引子和周期极限环共存现象。为了验证电路的混沌行为,将对设计的电路进行了PSpice仿真,电路仿真结果验证了理论分析的正确性。     

三阶非自治铁磁混沌电路的分析及控制

本文对一个LC串并联三阶非自治铁磁混沌电路的混沌动力学行为进行了理论研究和计算机仿真分析。得出几点重要结论：(1)此电路仅含一个由磁通链控制的非线性电感元件，可以作为一个四阶自治扭扩系统来分析。(2)通过计算机仿真验证，证实了该电路确实存在混沌动力学行为。(3)凡是能用本文提出三阶非线性非自治微分方程描述的工程物理系统都具有混沌性质。(4)提出了调整线性参数控制混沌法。     

一类电路系统的分岔分析及超混沌控制研究

为了揭示电路系统丰富的非线性动力学行为,提高电路系统的稳定性,避免混沌或超混沌电路对元器件的危害,针对一类电路系统模型,应用现代数学中的微分方程理论和非线性动力学的方法,分析了系统发生分岔的条件,并通过数值分析验证了该理论结果。研究发现系统在一定参数条件下存在内衣马克-沙克分岔和倍周期分岔,随着参数的变化系统演化为混沌和超混沌。针对目前超混沌控制方法的研究较少,而且控制的周期轨道多是低周期轨道,提出一种节约能量并能将系统控制到高倍周期和概周期的方法,为研究许多现实离散系统模型提供了一种新的方法,对于研究电路系统提供了一条新的思路,因而具有一定的理论意义和实用价值。     

含两个荷控忆阻器的五阶混沌电路研究

忆阻器作为一种具有记忆功能的新型非线性元件,被广泛应用于非线性电路系统设计中。利用两个基于荷控光滑模型的忆阻器以及采用常见的线性电子元件电感、电容、负电阻等设计了一种新的五阶混沌振荡电路。采用常规的系统动力学分析方法,分析了系统平衡点稳定性、相图、李雅普诺夫指数谱和分叉图,研究了系统随电路参数和荷控忆阻器初始状态变量变化的非线性动力学特性。Matlab数值仿真结果验证了理论分析的正确性。     

DC-DC Buck变换器中的混沌现象分析

DC-DC Buck变换器在满足一定条件时,随着开关的开合,会引起电路拓扑结构的变化,产生非线性系统的现象。本文在分析了电路的结构原理后,通过仿真更直观地观察到电路中的混沌现象,对不同的电压输入值产生的影响都做了详细的分析,为以后在Buck变换器设计中避免混沌现象的产生奠定了一定的理论基础。     

Inducing Chaos in Electronic Circuits by Resonant Perturbations

We propose a scheme to induce chaotic attractors in electronic circuits. The applications that we are interested in stipulate the following three constraints: 1) the circuit operates in a stable periodic regime far away from chaotic behavior; 2) no parameters or state variables of the circuit are directly accessible to adjustment and 3) the circuit equations are unknown and the only available information is a time series (or a signal) measured from the circuit. Under these conditions, a viable approach to chaos induction is to use external excitations such as a microwave signal, assuming that a proper coupling mechanism exists which allows the circuit to be perturbed by the excitation. The question we address in this paper is how to choose the waveform of the excitation to ensure that sustained chaos (chaotic attractor) can be generated in the circuit. We show that weak resonant perturbations with time-varying frequency and phase are generally able to drive the circuit into a hierarchy of nonlinear resonant states and eventually into chaos. We develop a theory to explain this phenomenon, provide numerical support, and demonstrate the feasibility of the method by laboratory experiments. In particular, our experimental system consists of a Duffing-type of nonlinear electronic oscillator driven by a phase-locked loop (PLL) circuit. The PLL can track the frequency and phase evolution of the target Duffing circuit and deliver resonant perturbations to generate robust chaotic attractors     

一种蔡氏硬件电路系统的研究

由于混沌是貌似随机的非随机运动。它对初始条件的极端敏感性。蔡氏电路出现后,通过非线性电路研究混沌产生涡卷成为可能,而蔡氏混沌电路产生涡卷吸引子方法多种多样,利用非线性多项式产生三涡卷混沌吸引子为例,对蔡氏电路进行数学模型分析,然后进行MATLAB仿真。再此基础上,对蔡氏电路进行Multisim仿真同样可以产生三涡卷混沌吸引子,并通过硬件电路系统实现,该硬件电路能够产生三涡卷吸引子,并且可作为一个信号发生电路应用。     

具有传输干扰的混沌全状态射影同步

针对具有传输干扰的混沌系统的同步问题,提出一种新的全状态射影同步方案.利用Lyapunov稳定性理论,设计了混沌系统的非线性观测器,得到了具有传输干扰的混沌系统射影同步的充分条件.该方案不仅能够得到以特定缩放因子的射影同步,并且可以在不降低可控性的条件下,根据控制的情况,任意调整缩放因子.利用鲁棒稳定性理论进一步证明了所提方案可大大减小传输干扰对混沌射影同步的影响,从而得到了满意的混沌全状态射影同步.最后,以陈氏系统为例,进行数值仿真,验证了所提方案能够有效地抑制混沌同步系统的信道干扰,得到混沌系统的全状态射影同步.     

Design and implementation of n-scroll chaotic attractors from a general jerk circuit

This paper proposes a novel nonlinear modulating function approach for generating n-scroll chaotic attractors based on a general jerk circuit. The systematic nonlinear modulating function methodology developed here can arbitrarily design the swings, widths, slopes, breakpoints, equilibrium points, shapes, and even the general phase portraits of the n-scroll chaotic attractors by using the adjustable sawtooth wave, triangular wave, and transconductor wave functions. The dynamic mechanism and chaos generation condition of the general jerk circuit are further investigated by analyzing the system stability. A simple block circuit diagram, including integrator, sawtooth wave and triangular wave generators, buffer, switch linkages, and voltage-current conversion resistors, is designed for the hardware implementations of various 3-12-scroll chaotic attractors via switchings of the switch linkages. This is the first time to experimentally verify a 12-scroll chaotic attractor generated by an analog circuit. In particular, the recursive formulas of system parameters and real physical circuit parameters are rigorously derived for the hardware implementations of the n-scroll chaotic attractors. Moreover, the adjustability of the nonlinear modulating function and the rigorous recursive formulas together provide a theoretical principle for the hardware implementations of various chaotic attractors with a large number of scrolls.     

一类非线性系统的混沌反控制研究

针对一类非线性系统的混沌反控制问题,借用非线性状态观测器概念设计实现混沌反控制的控制器。非混沌系统在控制器的控制下,在与混沌系统的输出实现同步的同时,使非混沌系统处于混沌状态,实现混沌反控制的目标。理论分析及仿真结果都证明该方案的有效性和可行性。     

对混沌信号应用于语音保密通信系统存在问题的解决方案

混沌信号应用于语音保密通信系统的理论研究日趋成熟,但迟迟得不到很有效的应用,主要原因是混沌电路存在几个尚未解决的难题,如产生混沌信号的电路所需电源电压过高,无法应用于实际系统;混沌信号的频带较宽,在实际系统传输时,部分频率的信号被滤除,无法实现混沌同步等问题,阻碍了混沌应用于语音保密通信的进程。本文以陈氏电路语音加密系统为例,提出了解决上述问题的方案,并进行了软件模拟和硬件电路测试,有较高的实用价值。     

Instability, subharmonics, and chaos in power electronic systems

The concept of chaos is applied to a variety of nonlinear power electronic circuits. With the onset of instability, the phenomena of subharmonics, quasi-periodicity, and chaos are predicted and observed. The following examples are dealt with: diodes with charge storage (with application to resonant converters); a ferroresonant circuit; a controlled thyristor rectifier circuit; and a Buck converter controlled by pulse-width modulation (PWM). The examples were chosen to model aspects of real power electronic systems. Analytical and experimental results demonstrate the complex nonlinear phenomena such as subharmonics, quasi-periodicity and chaos can arise in even the simplest systems     

Optical sequence generation based on collision avoidance usingchaotic mode transitions

An adaptive optical sequence generation scheme has been described in a nonlinear optical ring which exhibits chaotic dynamics. The adaptation is based on avoidance of collisions between the ring output and signals from another source. It is shown that collision-avoiding sequences can be autonomously selected via chaotic mode transitions induced by the feedback of collision signals. Experimental results demonstrate that the method can be successful for various collision signal patterns with different periods and pulsewidths. The mechanism of inducing chaos with collision signals is examined both experimentally and with numerical simulations and the results verify the effectiveness of the proposed adaptation method. A possible application of the proposed signal generation scheme in intelligent optical communication networks is mentioned