共查询到20条相似文献,搜索用时 15 毫秒
1.
S Rajasekar 《Pramana》1997,48(1):249-258
In this paper we consider the Bonhoeffer-van der Pol (BVP) equation which describes propagation of nerve pulses in a neural
membrane, and characterize the chaotic attractor at various bifurcations, and the probability distribution associated with
weak and strong chaos. We illustrate control of chaos in the BVP equation by the Ott-Grebogi-Yorke method as well as through
a periodic instantaneous burst. 相似文献
2.
S Rajasekar 《Pramana》1993,41(4):295-309
This paper investigates the possibility of controlling horseshoe and asymptotic chaos in the Duffing-van der Pol oscillator
by both periodic parametric perturbation and addition of second periodic force. Using Melnikov method the effect of weak perturbations
on horseshoe chaos is studied. Parametric regimes where suppression of horseshoe occurs are predicted. Analytical predictions
are demonstrated through direct numerical simulations. Starting from asymptotic chaos we show the recovery of periodic motion
for a range of values of amplitude and frequency of the periodic perturbations. Interestingly, suppression of chaos is found
in the parametric regimes where the Melnikov function does not change sign. 相似文献
3.
提出了一种对微弱周期信号的定量检测方法.分析混沌振子系统在大尺度周期状态下的相对稳定输出时,发现了混沌振子系统输出周期解的平均面积是一个比较稳定的几何特征量.该几何特征量与待测信号幅值之间存在比较稳定的单调递增关系.在一定的参数条件下,几何特征量精度可达到10-6V2.利用混沌系统对随机噪声信号的免疫性和对微弱周期信号的敏感性,进一步建立了微弱周期信号的定量检测方法.仿真实验表明,随着待检测幅度的增加,在保证检测精度的同时,抗噪性能也随之增强.
关键词:
混沌振子系统
大尺度周期相态
周期解的几何特征量
微弱周期信号的定量检测 相似文献
4.
Suppressing chaos by parametric perturbation at doubled frequency of periodic perturbation 下载免费PDF全文
An analysis of the chaos suppression of a nonlinear elastic beam(NLEB)is presented.In terms of modal transformation the equation of NLEB is reduced to the Duffing equation.It is shown that the chaotic behaviour of the NLEB is sensitively dependent on the parameters of perturbations and initial conditions.By adjusting the frequency of parametric perturbation to twice that of the periodic one and the amplitude of parametric pertubation to the same as the periodic one,the chaotic region of the nonlinear elastic beam driven by periodic force can be greatly suppressed. 相似文献
5.
Zambrano S Allaria E Brugioni S Leyva I Meucci R Sanjuán MA Arecchi FT 《Chaos (Woodbury, N.Y.)》2006,16(1):013111
A well-known method to suppress chaos in a periodically forced chaotic system is to add a harmonic perturbation. The phase control of chaos scheme uses the phase difference between a small added harmonic perturbation and the main driving to suppress chaos, leading the system to different periodic orbits. Using the Duffing oscillator as a paradigm, we present here an in-depth study of this technique. A thorough numerical exploration has been made focused in the important role played by the phase, from which new interesting patterns in parameter space have appeared. On the other hand, our novel experimental implementation of phase control in an electronic circuit confirms both the well-known features of this method and the new ones detected numerically. All this may help in future implementations of phase control of chaos, which is globally confirmed here to be robust and easy to implement experimentally. 相似文献
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非线性动力系统极易发生共振,在多频激励下可能发生联合共振或组合共振,目前关于非线性系统的主-超谐联合共振的研究少见报道.本文以Duffing系统为对象,研究系统在主-超谐联合共振时的周期运动和通往混沌的道路.应用多尺度法得到系统的近似解析解,并利用数值方法对解析解进行验证,结果吻合良好.基于Lyapunov第一方法得到稳态周期解的稳定性条件,并分析了非线性刚度对稳态周期解的幅值和稳定性的影响.此外,由于近似解只能描述周期运动,不足以描述系统的全局特性,因而应用Melnikov方法对系统进行全局分析,得到系统进入Smale马蹄意义下混沌的条件,依据该条件以及主-超谐联合共振的条件选取一组参数进行数值仿真.分岔图和最大Lyapunov指数显示出两个临界值:当激励幅值通过第一个临界值时,异宿轨道破裂,混沌吸引子突然出现,系统以激变方式进入混沌;激励幅值通过第二个临界值时,系统在混沌态下再次发生激变,进入另一种混沌态.利用Melnikov方法考察了第一个临界值在多种频率组合下的变化趋势,并用数值仿真验证了解析结果的正确性. 相似文献
9.
The bifurcation threshold value of the chaos detection system for a weak signal* 总被引:6,自引:0,他引:6 下载免费PDF全文
Recently, it has become an important problem to confirm the bifurcation threshold value of a chaos detectionsystem for a weak signal in the fields of chaos detection. It is directly related to whether the results of chaos detectionare correct or not. In this paper, the discrimination system for the dynamic behaviour of a chaos detection system fora weak signal is established by using the theory of linear differential equation with periodic coefficients and computingthe Lyapunov exponents of the chaos detection system; and then, the movement state of the chaos detection system isdefined. The simulation experiments show that this method can exactly confirm the bifurcation threshold value of thechaos detection svstem. 相似文献
10.
Bifurcations and chaos in the ubiquitous Duffing oscillator equation with different external periodic forces are studied numerically.
The external periodic forces considered are sine wave, square wave, rectified since wave, symmetric saw-tooth wave, asymmetric
saw-tooth wave, rectangular wave with amplitude-dependent width and modulus of sine wave. Period doubling bifurcations, chaos,
intermittency, periodic windows and reverse period doubling bifurcations are found to occur due to the applied forces. A comparative
study of the effect of various forces is performed. 相似文献
11.
The dynamical behaviour of the generalized Korteweg-de
Vries (KdV) equation under a periodic perturbation is investigated
numerically. The bifurcation and chaos in the system are observed by
applying bifurcation diagrams, phase portraits and Poincaré maps.
To characterise the chaotic behaviour of this system, the spectra of
the Lyapunov exponent and Lyapunov dimension of the attractor are also
employed. 相似文献
12.
WANG Yan-Qun WU Qin 《理论物理通讯》2007,48(3):477-480
The chaotic dynamics of a Duffing oscillator with a parametric force is investigated. By using the direct perturbation technique, we analytically obtain the general solution of the lst-order equation. Through the boundedness condition of the general solution we get the famous Melnikov function predicting the onset of chaos. When the parametric and external forces are strong, numerical simulations show that increasing the amplitude of the parametric or external force can lead the system into chaos via period doubling. 相似文献
13.
References: 《理论物理通讯》2007,48(9):477-480
The chaotic dynamics of a Duffing oscillator with a parametric force is investigated. By using the direct perturbation technique, we analytically obtain the general solution of the 1st-order equation. Through the boundedness condition of the general solution we get the famous Melnikov function predicting the onset of chaos. When the parametric and external forces are strong, numerical simulations show that increasing the amplitude of the parametric or external force can lead the system into chaos via period doubling. 相似文献
14.
We suggest a closed form expression for the path integral of quantum transition amplitudes. We introduce a quantum action with parameters different from the classical action. We present numerical results for the harmonic oscillator with weak perturbation, the quartic potential, and the double well potential. The quantum action is relevant for quantum chaos and quantum instantons. 相似文献
15.
《Physics letters. A》1999,260(5):345-351
The spatio-temporal chaos in the system described by a one-dimensional nonlinear-drift wave equation is controlled by directly adding a periodic force with appropriately chosen frequencies. By dividing the solution of the system into a carrier steady wave and its perturbation, we find that the controlling mechanism can be explained by a slaving principle. The critical controlling time for a perturbation mode increases exponentially with its wave number. 相似文献
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FANG Jian-Shu 《理论物理通讯》2003,39(5):555-558
We have obtained a general unstable chaotic solution of a typical nonlinear oscillator in a double potential trap with weak periodic perturbations by using the direct perturbation method. Theoretical analysis reveals that the stable periodic orbits are embedded in the Melnikov chaotic attractors. The corresponding chaotic region and orbits in parameter space are described by numerical simulations. 相似文献
18.
It is suggested that chaotic dynamical systems characterized by intermittent jumps between two preferred regions of phase space display an enhanced sensitivity to weak periodic forcings through a stochastic resonance-like mechanism. This possibility is illustrated by the study of the residence time distribution in two examples of bimodal chaos: the periodically forced Duffing oscillator and a 1-dimensional map showing intermittent behavior. 相似文献
19.
在前期实验工作的基础上,从理论分析的角度,提出了利用Duffing振子从大周期态向混沌态的相变 作为判据的微弱周期信号检测方法,给出了检测原理,并论证了其可行性;从过渡带影响和检测概率两方面 将该方法与传统的检测方法进行了比较分析,并对两者的检测性能进行了仿真对比.分析和仿真结果都显示,相同条件下, Duffing振子从大周期态向混沌态的相变受过渡带影响更小,所提方法具有更好的检测性能. 实验数据还表明, Duffing振子检测微弱信号只能基于单向相变, 利用阵发混沌进行频差检测只适用于待测信号信噪比较高的情况.
关键词:
Duffing
混沌
检测
过渡带 相似文献
20.
In this paper,the complicated dynamics and multi-pulse homoclinic orbits of a two-degree-of-freedom parametrically excited nonlinear nano-oscillator with coupled cubic nonlinearities are studied.The damping,parametrical excitation and the nonlinearities are regarded as weak.The averaged equation depicting the fast and slow dynamics is derived through the method of multiple scales.The dynamics near the resonance band is revealed by doing a singular perturbation analysis and combining the extended Melnikov method.We are able to determine the criterion for the existence of the multi-pulse homoclinic orbits which can form the Shilnikov orbits and give rise to chaos.At last,numerical results are also given to illustrate the nonlinear behaviors and chaotic motions in the nonlinear nano-oscillator. 相似文献