共查询到17条相似文献,搜索用时 203 毫秒
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针对带有完全未知的非线性不确定项和外界扰动的异结构分数阶时滞混沌系统的同步问题,基于Lyapunov稳定性理论,设计了自适应径向基函数(radial basis function,RBF)神经网络控制器以及整数阶的参数自适应律.该控制器结合了RBF神经网络和自适应控制技术,RBF神经网络用来逼近未知非线性函数,自适应律用于调整控制器中相应的参数.构造平方Lyapunov函数进行稳定性分析,基于Barbalat引理证明了同步误差渐近趋于零.数值仿真结果表明了该控制器的有效性. 相似文献
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对于离散混沌系统的最小能量控制问题,提出了一种框架性方法,该方法具有通用性.首先,设计一个二次目标函数,同时把混沌系统分解为线性部分和非线性部分两项和.然后,提出了求解非线性最优控制问题的两级算法:第一级对混沌系统中的非线性部分进行预估,以使原系统变为带有常数项的线性系统;第二级用动态规划求解一个非典型线性二次最优控制问题,并把解返回第一级,第一级根据第二级的解对非线性部分重新预估.这样通过两级间不断的信息交换,最终得到混沌系统的最优控制律.该方法不仅实现了对混沌系统的控制,而且在整个控制过程中消耗的控制能量最小.
关键词:
混沌系统
两级优化
最优控制 相似文献
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In this paper we report a time-delayed chameleon-like chaotic system which can belong to different families of chaotic attractors depending on the choices of parameters. Such a characteristic of self-excited and hidden chaotic flows in a simple 3D system with time delay has not been reported earlier. Dynamic analysis of the proposed time-delayed systems are analysed in time-delay space and parameter space. A novel adaptive modified functional projective lag synchronization algorithm is derived for synchronizing identical time-delayed chameleon systems with uncertain parameters. The proposed time-delayed systems and the synchronization algorithm with controllers and parameter estimates are then implemented in FPGA using hardware–software co-simulation and the results are presented. 相似文献
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The synchronization problem for a general class of uncertain chaotic systems is addressed. The underlying systems may be perturbed by unknown time-varying parameters, unstructured uncertainties, and external disturbances. Meanwhile, the time-varying parameters and disturbances are neither required to be periodic nor to have known bounds. Assuming the disturbances are L(2) signals, an adaptive control incorporated with H(∞) control technique is employed to construct a robust adaptive synchronization algorithm. Then, removing such assumption, a novel adaptive-based method is developed to achieve the goal of synchronization. In order to demonstrate the effectiveness of the proposed algorithms, such methods are applied to solve the synchronization problem of uncertain chaotic Chua's circuits. 相似文献
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Wangli He 《Physics letters. A》2008,372(4):408-416
In this Letter, synchronization of a class of chaotic neural networks with known or unknown parameters is investigated. By combing the adaptive control and linear feedback with update law, a simple, analytical, and rigorous adaptive feedback scheme is derived to achieve synchronization of two coupled neural networks with time-varying delay based on the invariant principle of functional differential equations and parameter identification. With this method, parameter identification and synchronization can be achieved simultaneously. Simulation results are given to justify the theoretical analysis. 相似文献
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In this Letter, we have dealt with the problem of lag synchronization and parameter identification for a class of chaotic neural networks with stochastic perturbation, which involve both the discrete and distributed time-varying delays. By the adaptive feedback technique, several sufficient conditions have been derived to ensure the synchronization of stochastic chaotic neural networks. Moreover, all the connection weight matrices can be estimated while the lag synchronization is achieved in mean square at the same time. The corresponding simulation results are given to show the effectiveness of the proposed method. 相似文献
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In this Letter we consider modified function projective synchronization of unidirectionally coupled multiple time-delayed Rossler chaotic systems using adaptive controls. Recently, delay differential equations have attracted much attention in the field of nonlinear dynamics. The high complexity of the multiple time-delayed systems can provide a new architecture for enhancing message security in chaos based encryption systems. Adaptive control can be used for synchronization when the parameters of the system are unknown. Based on Lyapunov stability theory, the adaptive control law and the parameter update law are derived to make the state of two chaotic systems are function projective synchronized. Numerical simulations are presented to demonstrate the effectiveness of the proposed adaptive controllers. 相似文献
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In this paper, the synchronization and the parameter identification
of the chaotic Pikovsky--Rabinovich (PR) circuits are investigated.
The linear error of the second corresponding variables is used to
change the driven chaotic PR circuit, and the complete
synchronization of the two identical chaotic PR circuits is realized
with feedback intensity k increasing to a certain threshold. The
Lyapunov exponents of the chaotic PR circuits are calculated by
using different feedback intensities and our results are confirmed.
The case where the two chaotic PR circuits are not identical is also
investigated. A general positive Lyapunov function V, which
consists of all the errors of the corresponding variables and
parameters and changeable gain coefficient, is constructed by using
the Lyapunov stability theory to study the parameter identification
and complete synchronization of two non-identical chaotic circuits.
The controllers and the parameter observers could be obtained
analytically only by simplifying the criterion dV/dt<0
(differential coefficient of Lyapunov function V with respect to
time is negative). It is confirmed that the two non-identical
chaotic PR circuits could still reach complete synchronization and
all the unknown parameters in the drive system are estimated exactly
within a short transient period. 相似文献