共查询到20条相似文献,搜索用时 15 毫秒
1.
通过对蔡氏电路的研究,提出了一种新的混沌系统,并对该系统的基本动力学特性进行了深入研究,得到该系统的Lyapunov指数和Lyapunov维数,给出了相图、Lyapunov指数谱、分岔图、Poincaré映射以及功率谱等.利用OrCAD-PSpice软件设计了该新混沌系统的振荡电路并进行了仿真实验.研究结果表明,该系统与蔡氏电路产生的混沌吸引子并不拓扑等价,且该系统的参数变化范围较大,最大Lyapunov指数接近1,数值仿真和电路系统实验仿真具有很好的一致性,证实了该系统的存在性和物理上可实现性.
关键词:
混沌系统
Lyapunov指数谱
分岔图
电路实现 相似文献
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提出利用Logistic混沌映射调制Unified混沌系统的参数,构建Logistic-Unified(LU)混杂混沌系统的思想.在Logistic混沌映射产生的随机数值的调制下,Unified混沌系统的参数随机变化,控制LU混杂混沌系统在广义Lorenz系统、Lü系统和广义Chen系统间随机切换,产生极其复杂的混沌信号.用数字信号处理(DSP)芯片对LU混杂混沌系统进行硬件实现,硬件实验与数值仿真结果一致,证明了理论分析的正确性.
关键词:
LU混杂混沌系统
切换律
Lyapunov指数
DSP 相似文献
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Time-dependent spherically symmetricSU(2) Yang-Mills-Higgs system is shown to be chaotic near the ’t Hooft-Polyakov monopole solution by calculating the maximal
Lyapunov exponents. A phase transition like behaviour from order to chaos is observed as a parameter depending on the self
interaction constant of scalar fields increases. 相似文献
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Control of chaos in permanent magnet synchronous motor by using optimal Lyapunov exponents placement
Permanent Magnet Synchronous Motor (PMSM) experiences chaotic behavior for a certain range of its parameters. In this case, since the performance of the PMSM degrades, the chaos should be eliminated. In this Letter, the control of the undesirable chaos in PMSM using Lyapunov exponents (LEs) placement is proposed that is also improved by choosing optimal locations of the LEs in the sense of predefined cost function. Moreover, in order to provide the physical realization of the method, nonlinear parameter estimator for the system is suggested. Finally, to show the effectiveness of the proposed methodology, the simulation results for applying this control strategy are provided. 相似文献
8.
This Letter focuses on the synchronization problem of a class of chaotic systems. A synchronization method is presented based on Lyapunov method and backstepping method. Finally some typical numerical examples are given to show the effectiveness of the theoretical results. 相似文献
9.
A new three-dimensional chaotic system with large scope of parameters is proposed. Its properties such as equilibrium points, Poincaré map, the largest Lyapunov exponent spectra and bifurcation diagrams are analyzed theoretically and numerically. Theoretical analyses and simulation tests indicate that the proposed chaotic system can keep chaotic in a wide range of parameters. The system is recommendable for many engineering applications such as secure communications, cryptology, information processing, etc. 相似文献
10.
本文通过引进一个非线性状态反馈控制器, 提出了一个新的四维混沌系统, 该混沌吸引子能在任何方向上都表现出四翼形式. 由于存在一个大的正李雅普诺夫指数, 混沌系统具有一些非常有趣和复杂的动力学行为. 对系统的一些基本动力学特性进行了数值模拟和理论分析, 如平衡点、耗散性、Poincaré映射、频谱、时域谱和混沌行为等. 通过对Lyapunov指数谱和分岔图的分析, 进一步研究了混沌行为的系统参数敏感性. 最后, 设计了一个实现四翼混沌系统的振荡电路, EWB观察结果与数值模拟结果具有良好的一致性. 相似文献
11.
This paper presents the finding of a novel chaotic system
with one source and two saddle-foci in a simple three-dimensional
(3D) autonomous continuous time Hopfield neural network. In
particular, the system with one source and two saddle-foci has a
chaotic attractor and a periodic attractor with different initial
points, which has rarely been reported in 3D autonomous systems. The
complex dynamical behaviours of the system are further investigated
by means of a Lyapunov exponent spectrum, phase portraits and
bifurcation analysis. By virtue of a result of horseshoe theory in
dynamical systems, this paper presents rigorous computer-assisted
verifications for the existence of a horseshoe in the system for a
certain parameter. 相似文献
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Andrea Crisanti Giovanni Paladin Angelo Vulpiani 《Journal of statistical physics》1988,53(3-4):583-601
We study the behavior of the generalized Lyapunov exponents for chaotic symplectic dynamical systems and products of random matrices in the limit of large dimensionsD. For products of random matrices without any particular structure the generalized Lyapunov exponents become equal in this limit and the value of one of the generalized Lyapunov exponents is obtained by simple arguments. On the contrary, for random symplectic matrices with peculiar structures and for chaotic symplectic maps the generalized Lyapunov exponents remains different forD , indicating that high dimensionality cannot always destroy intermittency. 相似文献
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在提出的一种压控忆阻器的基础上, 构造了最简的并联忆阻器混沌系统, 分析其动力学特性, 得到了该系统的Lyapunov指数和Lyapunov维数, 给出了时域波形、相图、Lyapunov指数谱、分岔图、Poincaré映射等. 利用EWB软件设计了该新混沌系统的振荡电路并进行了仿真实验. 研究结果表明, 忆阻器的i-v特性在参数的变化时, 并不保持斜“8”字形, 会变为带尾巴的扇形. 该混沌系统与磁控忆阻器混沌系统不同, 系统只有一个平衡点, 初始条件在系统能振荡的情况下不影响系统状态. 电路实验仿真结果和数值仿真具有很好的一致性, 证实了该系统的存在性和物理上可实现性.
关键词:
忆阻器
混沌电路
并联
动力学行为 相似文献
16.
The effect of noise in inducing order on various chaotically evolving systems is reviewed, with special emphasis on systems
consisting of coupled chaotic elements. In many situations it is observed that the uncoupled elements when driven by identical
noise, show synchronization phenomena where chaotic trajectories exponentially converge towards a single noisy trajectory,
independent of the initial conditions. In a random neural network, with infinite range coupling, chaos is suppressed due to
noise and the system evolves towards a fixed point. Spatiotemporal stochastic resonance phenomenon has been observed in a
square array of coupled threshold devices where a temporal characteristic of the system resonates at a given noise strength.
In a chaotically evolving coupled map lattice with the logistic map as local dynamics and driven by identical noise at each
site, we report that the number ofstructures (a structure is a group of neighbouring lattice sites for values of the variable follow which the certain predefined pattern)
follows a power-law decay with the length of the structure. An interesting phenomenon, which we callstochastic coherence, is also reported in which the abundance and lifetimes of these structures show characteristic peaks at some intermediate
noise strength. 相似文献
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Jinmei Liu 《Optik》2014
Many four-wing chaotic systems have been developed based on cross product or quadratic operations. Differently, we construct a three-dimensional chaotic system generating four-wing or double-wing attractors by virtue of sign function. Dynamical properties such as equilibrium points, Poincaré map, Lyapunov exponent spectra, Hopf bifurcations and bifurcation diagrams of the system are theoretically and numerically analyzed. Results of mathematical analyses and simulation tests indicate that the proposed chaotic system can keep chaotic to generate four-wing or double-wing attractors within a large scope of parameters. The system also shows hyperchaotic behaviors in some parameter range. Besides, circuit implementation of the chaotic system is studied. That proves the system is physically realizable. 相似文献
19.
Yingjie Zhang 《Journal of statistical physics》1996,82(5-6):1371-1384
Chaotic transient phenomena occur in the vicinity of nonattracting chaotic sets. The rate of escape measures the average length of the transients. There is a conjecture by Eckmann and Ruelle connecting the rate of escape to the Lyapunov exponents and entropy. We prove an inequality that partially supports the conjecture. 相似文献