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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 相似文献
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在混沌有益时,有目的地产生混沌已经成为混沌学研究的热点问题,本文提出直接延迟反馈实现混沌的反控制,在非混沌系统中产生了混沌.该方法与间接延迟反馈控制方法相比,控制更加简单,更易于实现.该方法与Pyragas提出的延迟反馈混沌控制方法的控制器结构相同,因此,这种直接延迟反馈控制方法可以在需要混沌时产生混沌,不需要混沌时控制混沌,实现混沌控制和反控制的统一,为设计者提供最大的灵活性.针对参数处于非混沌区的Chen系统和Lorenz系统的仿真结果表明了该混沌反控制方法的有效性.
关键词:
混沌
反控制
直接延迟反馈 相似文献
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探讨了非周期力(有界噪声或混沌驱动力)在非线性动力系统混沌控制中的影响.以一类典型的含有五次非线性项的Duffing-van der Pol系统为范例,通过对系统的轨道、最大Lyapunov指数、功率谱幅值及Poincar截面的分析,发现适当幅值的有界噪声或混沌信号,一方面可以消除系统对初始条件的敏感依赖性,抑制系统的混沌行为,将系统的混沌吸引子转化为奇怪非混沌吸引子;另一方面也可以诱导系统的混沌行为,将系统的周期吸引子转化为混沌吸引子.从而揭示了非周期力在混沌控制中的双重功效:抑制混沌和诱导混沌.
关键词:
混沌控制
有界噪声
混沌驱动力 相似文献
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讨论了具有有界随机参数的随机Bonhoeffer-Van der Pol系统的随机混沌现象,并利用噪声对其进行控制.首先运用Chebyshev多项式逼近的方法,将随机Bonhoeffer-Van der Pol系统转化为等价的确定性系统,使原系统的随机混沌控制问题转换为等价的确定性系统的确定性混沌控制问题,继而可用Lyapunov指数指标来研究等价确定性系统的确定性混沌现象和控制问题.数值结果表明,随机Bonhoeffer-Van der Pol系统的随机混沌现象与相应的确定性Bonhoeffer-Van der Pol系统极为相似.利用噪声控制法可将混沌控制到周期轨道,但是在随机参数及其强度的影响下也呈现出一些特点. 相似文献
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本文利用非共振参数策动实现对Chen系统的非反馈方式混沌控制.使用远大于系统平均频率的周期信号作为控制输入,将控制系统中的系统变量分解为按系统平均频率变化的慢变量和按外加控制信号频率变化的快变量,然后利用平均法对控制系统进行处理得到慢变系统;根据慢变系统的动力学性质,得出所用控制参数应满足的条件.数值仿真结果表明此方法可以使控制系统迅速达到目标状态,并且在控制信号受到噪声干扰时,在一定信噪比范围内仍能对系统进行有效的控制,证明了该方法的可行性.
关键词:
平均法
Chen系统
混沌控制 相似文献
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In this paper, a chaos system and proportional
differential control are both used to detect the frequency of an
unknown signal. In traditional methods the useful signal is obtained
through the Duffing equation or other chaotic oscillators. But these
methods are too complex because of using a lot of chaos oscillators.
In this paper a new method is presented that uses the R?ssler
equation and proportional differential control to detect a weak
signal frequency. Substituting the detected signal frequency into
the R?ssler equation leads the R?ssler phase state to be
considerably changed. The chaos state can be controlled through the
proportional differential method. Through its phase diagram and
spectrum analysis, the unknown frequency is obtained. The simulation
results verify that the presented method is feasible and that the
detection accuracy is higher than those of other methods. 相似文献
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Circuitry implementation of a novel nonautonomous hyperchaotic Liu system based on sine input
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Based on the three-dimensional Liu system with a nonlinear term of
square, this paper appends a state variable to the system, and
further adds a driving signal of the sine signal to construct a
novel 4-demensional nonautonomous hyperchaotic Liu system. The
appended variable is formed by the product of the nonlinear
quadratic term of the original state variables and the driving
signal. Through adjusting the frequency of the driving signal, the
system can be controlled to show some different dynamic behaviors.
By numerical simulations, the Lyapunov exponent spectrums,
bifurcation diagrams and phase diagrams of the novel systems are
analyzed. Furthermore, the corresponding hardware circuits are
implemented. Both the experimental results and the simulation
results confirm that the method is feasible. The method, which
adjusts the frequency of the input sine signal to control the system
to show different dynamic behaviors, can make the dynamic property
of the system become more complex, but easier to be controlled
accurately as well. 相似文献
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将结构奇异值μ综合鲁棒控制技术应用于主动抗振控制系统中,并用于解决光学移相干涉仪抗振系统的不确定性问题.采用小波分析方法将随机振动信号进行时频分析后得到低频全局信息,随后运用μ综合D-K迭代法设计鲁棒μ控制器对低频振动进行抑制.该方法克服了由模型自身和外部干扰所引起的不确定性,使得控制系统能够有效地抑制抗振模型的不确定性和外部振动的干扰,同时也具有很高的控制准确度和灵敏度.仿真结果表明,该方法使光学移相干涉仪在外部振动的干扰下具有较好的鲁棒稳定性和控制准确度,同时也能较好地抑制低频振动. 相似文献
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在前馈有源噪声控制系统中,建模信号与控制信号相互影响,建模信号的引入会导致系统降噪性能变差。为了减小建模信号的影响,提出一种基于能量比调控的次级通道在线建模有源噪声控制算法。利用控制过程与建模过程的误差能量比构造步长调控函数,分别调节控制过程与建模过程的步长值,从而减弱两者的相互影响。在次级通道建模过程中,对建模步长值采取分段调控的方法,并通过建模步长值的变化来调节建模信号,从而提升系统降噪性能。仿真结果表明,对于低频噪声信号的有源噪声控制,相比已有算法,提出的算法能获得较快的建模收敛速度和较高的降噪量。 相似文献
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This paper deals with the global reduction of axial flow fan noise in ducts in a building using a hybrid passive-active noise control method. The effectiveness of using an infra-red device as a reference signal source is also investigated. It is shown that using such a hybrid noise control system over an axial-flow fan reduces the overall sound pressure level by 5 dB(A) in the surrounding environment and global control of the blade passing frequency can also be achieved. This paper also shows that using an infra-red device as a reference signal source produces marginally better control as compared with using a microphone reference sensor. Moreover, long term stability is guaranteed and the possibility of acoustic feedback is eliminated. 相似文献
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Hirata H Kuyama T Ono M Shimoyama Y 《Journal of magnetic resonance (San Diego, Calif. : 1997)》2003,164(2):265-241
A frequency modulation (FM) method was developed to measure electron paramagnetic resonance (EPR) absorption. The first-derivative spectrum of 1,1-diphenyl-2-picrylhydrazyl (DPPH) powder was measured with this FM method. Frequency modulation of up to 1.6 MHz (peak-to-peak) was achieved at a microwave carrier frequency of 1.1 GHz. This corresponds to a magnetic field modulation of 57microT (peak-to-peak) at 40.3 mT. By using a tunable microwave resonator and automatic control systems, we achieved a practical continuous-wave (CW) EPR spectrometer that incorporates the FM method. In the present experiments, the EPR signal intensity was proportional to the magnitude of frequency modulation. The background signal at the modulation frequency (1 kHz) for EPR detection was also proportional to the magnitude of frequency modulation. An automatic matching control (AMC) system reduced the amplitude of noise in microwave detection and improved the baseline stability. Distortion of the spectral lineshape was seen when the spectrometer settings were not appropriate, e.g., with a lack of the open-loop gain in automatic tuning control (ATC). FM is an alternative to field modulation when the side-effect of field modulation is detrimental for EPR detection. The present spectroscopic technique based on the FM scheme is useful for measuring the first derivative with respect to the microwave frequency in investigations of electron-spin-related phenomena. 相似文献