共查询到19条相似文献,搜索用时 109 毫秒
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针对一类混沌系统, 当不满足观测器匹配条件时, 讨论了基于观测器的混沌同步及保密通讯问题.通过设计辅助驱动信号, 使得观测器匹配条件得以满足.为了处理辅助驱动信号中的未知变量, 使用高增益观测器作为近似微分器, 不仅给出了辅助驱动信号的估计值, 还给出了辅助驱动信号的微分估计值.基于辅助驱动信号的估计值, 提出了一种能与非线性项和干扰影响解耦的降维观测器作为响应系统, 达到了与驱动系统的同步.在同步的基础上, 再基于辅助驱动信号及其微分的估计值, 提出了一种保密信息还原的方法.最后, 针对Rössler系统进行仿真, 仿真结果表明所提出的方法是有效的.
关键词:
辅助驱动信号
混沌同步
降维观测器
保密通讯 相似文献
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分别用状态观测器法、主动控制法和Backstepping法研究了含有常数项的新Lü混沌系统的自同步问题.针对非严格反馈的新Lü混沌系统,分别基于以上三种方法设计了自适应控制器,依据Lyapunov稳定性原理证明了这些控制器能够较好地实现新Lü混沌系统的渐近自同步.数值仿真实验进一步验证了以上三种同步方法的有效性.经对三种同步方法比较分析,发现基于状态观测器的同步方法更加灵活高效.
关键词:
混沌同步
状态观测器
主动控制
Backstepping 相似文献
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Generalized reduced-order synchronization of chaotic system based on fast slide mode 总被引:1,自引:0,他引:1 下载免费PDF全文
A new kind of generalized reduced-order synchronization of different chaotic
systems is proposed in this paper. It is shown that dynamical evolution of
third-order oscillator can be synchronized with the canonical projection of
a fourth-order chaotic system generated through nonsingular states
transformation from a cell neural net chaotic system. In this sense, it is
said that generalized synchronization is achieved in reduced-order. The
synchronization discussed here expands the scope of reduced-order
synchronization studied in relevant literatures. In this way, we can achieve
generalized reduced-order synchronization between many famous chaotic
systems such as the second-order D\"{u}ffing system and the third-order
Lorenz system by designing a fast slide mode controller. Simulation results
are provided to verify the operation of the designed synchronization. 相似文献
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Fanglai Zhu 《Physics letters. A》2008,372(3):223-232
The Letter deals with the problem of synchronization of chaotic dynamic system with unknown disturbances and parameters based on observer. First, under some assumptions for drive system, a kind of full-order observer-based synchronization method is summarized. The response system is a robust adaptive full-order observer with adaptation laws for the unknown disturbances and parameters. Second, under the same assumptions, a reduced-order observer-based response system which can synchronize part states of drive system is developed. By choosing a special reduced-order gain matrix, the reduced-order observer-based response system is able to eliminate the influence of the unknown disturbances and parameters directly, so it is unnecessary for one to design the adaptation laws of them. Finally, some numerical simulations for Lorenz chaotic system are design and the simulation results are analyzed in detail. 相似文献
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By introducing an additional state feedback into classic Rikitake system, a new hyperchaotic system without equilibrium is derived. The proposed system is investigated through numerical simulations and analyses including time phase portraits, Lyapunov exponents, and Poincaré maps. Based on adaptive control and Lyapunov stability theory, we design a reduced-order projective synchronization scheme for synchronizing the hyperchaotic Rikitake system coexisting without equilibria and the original classic Rikitake system coexisting with two non-hyperbolic equilibria. Finally, numerical simulations are given to illustrate the effectiveness of the proposed synchronization scheme. 相似文献
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This paper deals with the problem of chaos control and
synchronization of the Chen--Liao system. From rigorous mathematic
justification, the chaotic trajectories of the Chen--Liao system are
led to a type of points whose four-dimensional coordinates have a
particular functional relation among them. Meanwhile, a new
synchronization manner, reduced-order generalized synchronization
(RGS), is proposed which has the characteristic of having a
functional relation between the slave and the partial master systems.
It is shown that this new synchronization phenomenon can be realized
by a novel technique. Numerical simulations have verified the
effectiveness of the proposed scheme. 相似文献
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基于Lyapunov稳定性理论、最优控制原理以及分步设计方法, 为神经元系统设计了非线性反馈控制器和最优控制器. 其中非线性反馈控制器能使得两个神经元系统之间的轨道误差趋于零, 最优控制器使得在同步过程中所花费的能量达到最低. 本文以Cable模型为例, 实现了两个神经元模型的全阶最优同步; 以Cable 模型和Hindmarsh-Rose (HR)模型为例, 实现了两个神经元模型的降阶最优同步; 同时, 均能有效地辨识出系统参数. 最后通过数值模拟进一步验证了本方案的有效性. 相似文献
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Joints play an important role in the dissipation of vibration energy in built-up structures. The highly nonlinear nature of joints with micro-slip is the main hurdle in developing a reduced-order model which can simulate the dynamic behaviour of a joint for a wide range of excitation conditions and geometries. In this paper, the proper orthogonal decomposition is applied to joint dynamics in an attempt to arrive at a generic reduced-order model without a compromise on the physics of the system. Only the linear part of the system of equations is reduced. The nonlinear part is determined in the full space and then reduced before the numerical integration phase. The major reduction in computational time is achieved by the increase in the size of the stable time step and the reduced number of coordinates in the integration phase. The reduced-order model, which is derived for an isolated and harmonically excited joint, is successfully applied to separate joints with different geometries and excitation conditions, e.g. harmonic and impulsive. The model is also capable of simulating the dynamics of structures with joints. The results of the reduced-order model show good agreement with a full model both in terms of the state of the system and its hysteretic behaviour. 相似文献
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A reduced-order model was developed to calculate the redox kinetics of oxygen carrier in chemical looping combustion. The reduced-order model can describe the major physical/chemical features of the redox steps of oxygen carrier, such as gas diffusion around and inside the particle, surface reaction, product growth, product layer diffusion, pore structure change etc. It is an analytical model simplified using the Thiele modulus method and thus is much easier for computational fluid dynamics modeling and reactor design. The accuracy of variations of redox conversion under different temperatures and gas concentrations predicted by the reduced-order model is verified by comparison with both the detailed one-dimensional model and the experimental data. The results indicate that the reduced-order model can reproduce the prediction accuracy of the detailed one-dimensional model and agrees well with the experimental data. The well observed two-stage behavior of a fast initial stage followed by a second slower stage was discussed in detail. Further, the reduced-order model was used to analyze the effect of particle structural parameters on the kinetics. The relative importance of each controlling step in the kinetics of oxygen carrier predicted by the reduced-order model was compared. 相似文献
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Xianghong Ma Alexander F. Vakakis Lawrence A. Bergman 《Journal of sound and vibration》2008,309(3-5):569-587
The Karhunen–Loeve (K–L) decomposition method has become a popular technique to create low-dimensional, reduced-order models of dynamical systems. In this paper this technique is applied to a multi-degree-of-freedom chain of linear coupled oscillators with a strongly nonlinear (nonlinearizable), lightweight end attachment. By performing K–L decomposition we show that the lightweight nonlinear attachment (possessing 0.5% of the total mass of the chain) can affect the global dynamics of the linear chain, exhibiting nonlinear energy-pumping phenomena; that is, irreversible passive targeted energy transfers from the linear chain to the nonlinear end attachment, where this energy is locally confined and dissipated without ‘spreading back’ to the primary system. It is shown that the occurrence of energy pumping can be identified by studying the dominant K–L modes of the dynamics, as well as, the energy distribution among them. Moreover, by comparing the action of the strongly nonlinear attachment to the classical linear vibration absorber, we show robustness of passive nonlinear energy absorption over wide parameter ranges. On the other hand, the case-sensitive nature of K–L-based reduced-order models has always been a constraint for K–L decomposition, since one cannot quantify a priori the error bound of such low-dimensional reduced-order models when different initial conditions are applied to the system. To alleviate this constraint, the paper proposes a multiple correlation coefficient (MCC) as a quantitative measure to effectively assess the applicability of a K–L-based reduced-order model derived for a specific set of initial conditions to a small neighborhood of initial conditions containing that initial state. The derived reduced-order models are validated through reconstruction of the system responses and comparisons to direct numerical integrations. 相似文献
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For the general discrete singular system with unknown inputs, a new reduced-order observer is designed. Anumerical example is presented to illustrate the design algorithms. 相似文献