共查询到20条相似文献,搜索用时 31 毫秒
1.
Five interesting experiments have been done for a class of chaos synchronization systems with unknown parameters and unknown control directions. And three important conclusions about parameters identification have been made. First, a necessary and sufficient condition for parameters identification is obtained. Second, a Nussbaum method is proposed to solve the problem of unknown control direction. Third, the adaptive method is not infinitely effective considered for our current ability of computation and simulation algorithm. 相似文献
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This work is concerned with the general methods for modified projective synchronization of hyperchaotic systems. A systematic method of active control is developed to synchronize two hyperchaotic systems with known parameters. Moreover, by combining the adaptive control and linear feedback methods, general sufficient conditions for the modified projective synchronization of identical or different chaotic systems with fully unknown or partially unknown parameters are presented. Meanwhile, the speed of parameters identification can be regulated by adjusting adaptive gain matrix. Numerical simulations verify the effectiveness of the proposed methods. 相似文献
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《Physics letters. A》2005,342(4):299-304
Based on Lyapunov stabilization theory, an adaptive controller with parameters identification for a class of chaotic systems with unknown parameters is proposed in this Letter. The proposed control scheme is successfully applied to some typical chaotic systems, which can be spilt into two terms: one is the term with known states, the other is the symmetric matrix term with unknown parameters, such as Lorenz system. And with the proposed adaptive control law, the two unified systems with unknown parameter are also to be synchronized. Simulation results verify the proposed scheme's effectiveness. 相似文献
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Adaptive lag synchronization and parameters adaptive lag identification of chaotic systems 总被引:1,自引:0,他引:1
This Letter investigates the problem of adaptive lag synchronization and parameters adaptive lag identification of chaotic systems. In comparison with those of existing parameters identification schemes, the unknown parameters are identified by adaptive lag laws, and the delay time is also identified in this Letter. Numerical simulations are also given to show the effectiveness of the proposed method. 相似文献
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A.I. Nazimov A.N. Pavlov A.A. Nazimova V.V. Grubov A.A. Koronovskii E. Sitnikova A.E. Hramov 《The European physical journal. Special topics》2013,222(10):2713-2722
A problem of recognition specific oscillatory patterns in the electroencephalograms with the continuous wavelet-transform is discussed. Aiming to improve abilities of the wavelet-based tools we propose a serial adaptive method for sequential identification of EEG patterns such as sleep spindles and spike-wave discharges. This method provides an optimal selection of parameters based on objective functions and enables to extract the most informative features of the recognized structures. Different ways of increasing the quality of patterns recognition within the proposed serial adaptive technique are considered. 相似文献
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In this paper, the chaos control and the synchronization of two fractional-order Liu chaotic systems with unknown parameters are studied. According to the Lyapunov stabilization theory and the adaptive control theorem, the adaptive control rule is obtained for the described error dynamic stabilization. Using the adaptive rule and a proper Lyapunov candidate function, the unknown coefficients of the system are estimated and the stabilization of the synchronizer system is demonstrated. Finally, the numerical simulation illustrates the efficiency of the proposed method in synchronizing two chaotic systems. 相似文献
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In this Letter, an adaptive control scheme is developed to study the anti-synchronization behavior between two identical and different chaotic systems with unknown parameters. This adaptive anti-synchronization controller is designed based on Lyapunov stability theory and an analytic expression of the controller with its adaptive laws of parameters is shown. The adaptive anti-synchronization between two identical systems (Chen system) and different systems (Genesio and Lü systems) are taken as two illustrative examples to show the effectiveness of the proposed method. Theoretical analysis and numerical simulations are shown to verify the results. 相似文献
10.
Parameters identification and adaptive full state hybrid projective synchronization of chaotic (hyper-chaotic) systems 总被引:1,自引:0,他引:1
Based on the active control idea and the invariance principle of differential equations, a general scheme of adaptive full state hybrid projective synchronization (FSHPS) and parameters identification of a class of chaotic (hyper-chaotic) systems with linearly dependent uncertain parameters is proposed in this Letter. With this effective scheme parameters identification and FSHPS of chaotic and hyper-chaotic systems can be realized simultaneously. Numerical simulations on the chaotic Chen system and the hyper-chaotic Chen system are presented to verify the effectiveness of the proposed scheme. 相似文献
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In practical situation, there exists many uncertain information in complex networks, such as the topological structures. So the topology identification is an important issue in the research of the complex networks. Based on LaSalle's invariance principle, in this Letter, an adaptive controlling method is proposed to identify the topology of a weighted general complex network model with non-delayed and delayed coupling. Finally, simulation results show that the method is effective. 相似文献
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In this paper, an adaptive fuzzy neural controller (AFNC) for a class of unknown chaotic systems is proposed. The proposed
AFNC is comprised of a fuzzy neural controller and a robust controller. The fuzzy neural controller including a fuzzy neural
network identifier (FNNI) is the principal controller. The FNNI is used for online estimation of the controlled system dynamics
by tuning the parameters of fuzzy neural network (FNN). The Gaussian function, a specific example of radial basis function,
is adopted here as a membership function. So, the tuning parameters include the weighting factors in the consequent part and
the means and variances of the Gaussian membership functions in the antecedent part of fuzzy implications. To tune the parameters
online, the back-propagation (BP) algorithm is developed. The robust controller is used to guarantee the stability and to
control the performance of the closed-loop adaptive system, which is achieved always. Finally, simulation results show that
the AFNC can achieve favourable tracking performances. 相似文献
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《Physics letters. A》2002,299(4):353-358
A novel control method is proposed for a class of chaotic systems dependent linearly on unknown parameters based upon adaptive control. With this method parameters identification and synchronization of chaotic systems can be achieved simultaneously. Simulation results with Lorentz system and Chen's system are presented to show the effectiveness of the approach. 相似文献
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D. Chakraborty 《The European Physical Journal B - Condensed Matter and Complex Systems》2012,85(8):1-8
This paper presents an adaptive lag synchronization based method for simultaneous identification of topology and parameters of uncertain general complex dynamical networks with and without time delays. Based on Lyapunov stability theorem and LaSalle??s invariance principle, an adaptive controller is designed to realize lag synchronization between drive and response systems, meanwhile, identification criteria of network topology and system parameters are obtained. Numerical simulations illustrate the effectiveness of the proposed method. 相似文献
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Based on the bounded property and statistics of chaotic signal and the idea of set-membership identification, we propose a set-membership generalized least mean square (SM-GLMS) algorithm with variable step size for blind adaptive channel equalization in chaotic communication systems. The steady state performance of the proposed SM-GLMS algorithm is analysed, and comparison with an extended Kalman filter (EKF)-based adaptive algorithm and variable gain least mean square (VG-LMS) algorithm is performed for blind adaptive channel equalization. Simulations show that the proposed SM-GLMS algorithm can provide more significant steady state performance improvement than the EKF-based adaptive algorithm and VG-LMS algorithm. 相似文献
18.
Periodic synchronization of community networks with non-identical nodes uncertain parameters and adaptive coupling strength 下载免费PDF全文
In this paper, we propose a novel approach for simultaneously identifying unknown parameters and synchronizing time-delayed complex community networks with nonidentical nodes. Based on the LaSalle's invariance principle, a cri- teflon is established by constructing an effective control identification scheme and adjusting automatically the adaptive coupling strength. The proposed control law is applied to a complex community network which is periodically synchro- nized with different chaotic states. Numerical simulations are conducted to demonstrate the feasibility of the proposed method. 相似文献
19.
Generalized projective synchronization of a class of chaotic (hyperchaotic) systems with uncertain
parameters 总被引:1,自引:0,他引:1 下载免费PDF全文
In this paper is investigated the generalized projective
synchronization of a class of chaotic (or hyperchaotic) systems, in
which certain parameters can be separated from uncertain parameters.
Based on the adaptive technique, the globally generalized projective
synchronization of two identical chaotic (hyperchaotic) systems is
achieved by designing a novel nonlinear controller. Furthermore, the
parameter identification is realized simultaneously. A sufficient
condition for the globally projective synchronization is obtained.
Finally, by taking the hyperchaotic Lü system as example, some
numerical simulations are provided to demonstrate the effectiveness
and feasibility of the proposed technique. 相似文献
20.
Genera/dynamical networks with distributed time delays are studied. The topology of the networks are viewed as unknown parameters, which need to be identified. Some auxiliary systems (also called the network estimators) are designed to achieve this goal. Both linear feedback control and adaptive strategy are applied in designing these network estimators. Based on linear matrix inequalities and the Lyapunov function method, the sufficient condition for the achievement of topology identification is obtained. This method can also better monitor the switching topology of dynamical networks. Illustrative examples are provided to show the effectiveness of this method. 相似文献