Decentralized adaptive synchronization of an uncertain complex delayed dynamical network

In this paper, we investigate the locally and globally adaptive synchronization problem for an uncertain complex dynamical network with time-varying coupling delays based on the decentralized control. The coupling terms here are bounded by high-order polynomials with known gains that are ubiquitous in a large class of complex dynamical networks. We generalize the usual technology of searching for an appropriate coordinates transformation to change the network dynamics into a series of decoupled lower-dimensional systems. Several adaptive synchronization criteria are derived by constructing the Lyapunov-Krasovskii functional and Barbalat lemma, and the proposed criteria are simple in form and convenient for the practical engineering design. Numerical simulations illustrated by a nearest-neighbor coupling network verify the effectiveness of the proposed synchronization scheme.     

On pinning synchronization of complex dynamical networks

There exist some fundamental and yet challenging problems in pinning control of complex networks: (1) What types of pinning schemes may be chosen for a given complex network to realize synchronization? (2) What kinds of controllers may be designed to ensure the network synchronization? (3) How large should the coupling strength be used in a given complex network to achieve synchronization? This paper addresses these technique questions. Surprisingly, it is found that a network under a typical framework can realize synchronization subject to any linear feedback pinning scheme by using adaptive tuning of the coupling strength. In addition, it is found that the nodes with low degrees should be pinned first when the coupling strength is small, which is contrary to the common view that the most-highly-connected nodes should be pinned first. Furthermore, it is interesting to find that the derived pinning condition with controllers given in a high-dimensional setting can be reduced to a low-dimensional condition without the pinning controllers involved. Finally, simulation examples of scale-free networks are given to verify the theoretical results.     

Pinning control of a generalized complex dynamical network model

This paper investigates the local and global synchronization of a generalized complex dynamical network model with constant and delayed coupling. Without assuming symmetry of the couplings, we proved that a single controller can pin the generalized complex network to a homogenous solution. Some previous synchronization results are generalized. In this paper, we first discuss how to pin an array of delayed neural networks to the synchronous solution by adding only one controller. Next, by using the Lyapunov functional method, some sufficient conditions are derived for the local and global synchronization of the coupled systems. The obtained results are expressed in terms of LMIs, which can be efficiently checked by the Matlab LMI toolbox. Finally, an example is given to illustrate the theoretical results.     

一类具有多种耦合时滞的复杂动态网络的牵制同步

针对一类由Lur'e系统组成的具有多种耦合时滞的加权复杂动态网络,研究其同步问题.只对网络中的一部分节点进行控制,从而使整个被控网络达到同步.基于绝对稳定性理论.得到了保证复杂网络实现全局同步的时滞独立判据.仿真中以蔡氏振荡器组成的复杂网络为例,验证了所提方法的有效性,且表明在某些特殊情况下,只需控制一个节点便可使整个网络达到同步.     

Pinning synchronization of complex delayed dynamical networks via generalized intermittent adaptive control strategy

In this paper, the problem of pinning synchronization for delayed complex directed networks via generalized intermittent adaptive control strategy is considered. First, a dynamical mode of delayed network is investigated. Second, a generalized intermittent adaptive control strategy which unified the traditional periodic intermittent control and the aperiodic case is introduced. Additionally, by constructing a piecewise Lyapunov auxiliary function and making use of piecewise analysis technique, some effective and novel criteria to ensure the global synchronization of delayed complex networks based on the designed control protocols are obtained. Finally, an example with numerical simulations is provided to demonstrate the validness of the theoretical results proposed scheme.     

一类时滞复杂动态网络的鲁棒自适应同步问题

针对一类耦合时滞复杂网络,基于变结构控制研究其同步问题.首先,利用系统的左特征向量函数设计切换面,使网络的运动轨线在期望的同步轨道保持稳定;然后,针对网络中的非线性项已知和未知时,分别设计相应的滑模控制器,使从任意时刻出发的动态网络轨线都能在有限时间内同步到达期望的轨道;最后,利用所设计的控制器对两个算例进行仿真,仿真结果说明了所设计控制器的有效性.     

复杂动态网络自适应有限时间同步控制

本文利用自适应控制的方法,研究了复杂动态网络有限时间同步控制问题.针对网络的耦合权重已知和耦合权重未知两种情况,分别设计了相应的自适应控制器和参数自适应律.利用有限时间稳定性定理和Lyapunov稳定性理论,证明了复杂动态网络的误差动态系统是有限时间稳定的,并给出了同步过渡时间上界的估计.最后,利用数值算例验证了本文结论的有效性.     

一种新的复杂动态网络学习控制的自适应同步算法

提出了一种新的具有未知时变参数复杂动态网络同步的自适应学习控制方法.运用重新参数化技术,设计周期时变参数的自适应学习律、常参数的更新律以及自适应控制策略确保同步误差渐近收敛.通过构造复合能量函数给出同步的一个充分条件.最后给出一个复杂网络的例子验证所提方法的有效性.     

Passivity-based control and synchronization of general complex dynamical networks

This paper presents some sufficient conditions for complex dynamical networks with and without coupling delays in the state to be passive. Based on the passivity property and linearization, control and synchronization of the dynamical networks are also addressed. An example and simulation results are included.     

Controlled synchronization of complex network with different kinds of nodes

In this paper, a new dynamical network model is introduced, in which the nodes of the network are different. It is shown that by the designed controllers, the state of the network can exponentially synchronize onto a homogeneous stationary state. Some criteria are derived and some examples are presented. The numerical simulations coincide with theoretical analysis.     

Cluster synchronization in directed networks of partial-state coupled linear systems under pinning control

This paper investigates the cluster synchronization for network of linear systems via a generalized pinning control strategy which allows the network of each cluster to take relaxed topological structure. For the case with fixed topology, it is shown that a feasible feedback controller can be designed to achieve the given cluster synchronization pattern if the induced network topology of each cluster has a directed spanning tree and further compared to the couplings among different clusters, the couplings within the each cluster are sufficiently strong. An extra balanced condition is imposed on the network topology of each cluster to allow for the cluster synchronization under arbitrary switching network topologies. Such a balanced condition can be removed via the use of dwell-time technique. For all the cases, the lower bounds for such strengths of couplings within each cluster that secure the synchronization as well as cluster synchronization rate are explicitly specified. Finally, some illustrative examples are provided to demonstrate the effectiveness of the theoretical findings.     

时变复杂动力学网络的同步控制

研究时变复杂动力学网络的同步控制问题.假定网络模型中的同步轨迹及耦合配置矩阵、内部耦合矩阵的各元素均有界,当这些界值可以预估或不确定时,分别应用线性反馈控制和自适应反馈控制策略使该网络实现全局同步.通过构造Lyapunov函数,证明了对于任意初始状态的时变复杂动力学网络模型在相应的控制手段下总可以实现渐近同步.特别是设计的自适应反馈控制策略对网络的拓扑结构、节点间的耦合强度及时滞等因素表现出较强的鲁棒性.数值仿真证实了上述结论的有效性.     

Synchronization for general complex dynamical networks with sampled-data

In this paper, the sampled-data synchronization control problem is investigated for a class of general complex networks with time-varying coupling delays. A rather general sector-like nonlinear function is used to describe the nonlinearities existing in the network. By using the method of converting the sampling period into a bounded time-varying delay, the addressed problem is first transformed to the problem of stability analysis for a differential equation with multiple time-varying delays. Then, by constructing a Lyapunov functional and using Jensen's inequality, a sufficient condition is derived to ensure the exponential stability of the resulting delayed differential equation. Based on that, the desired sampled-data feedback controllers are designed in terms of the solution to certain linear matrix inequalities (LMIs) that can be solved effectively by using available software. Finally, a numerical simulation example is exploited to demonstrate the effectiveness of the proposed sampled-data control scheme.     

时变耦合复杂网络同步的自适应控制

应用自适应控制策略实现时变耦合复杂网络的同步。通过构造layapunov函数,证明了对于任意初始状态的时变耦合复杂动力学网络模型在相应的控制手段下总可以实现渐近同步,数值仿真证实了此控制策略的有效性。     

具有间歇耦合的复杂动态网络量化同步分析

讨论了基于量化控制信号的间歇耦合复杂动态网络的同步动力学,根据脉冲间隔周期和量化器的特征,并利用稳定性理论和 Razumikhin 定理,分别给出了含时滞和不含时滞下的复杂动态网络同步化准则.网络节点间在一系列分段周期内有耦合,耦合过程中控制作用通过“对数量化器”对同步误差的反馈控制瞬态信号进行量化.所得理论结果进一步应用于由 Chua 混沌系统为动力节点所构成的复杂动态网络,数值模拟表明了所获理论结果的有效性.     

分数阶复杂网络的混合投影同步研究

主要针对一类节点为分数阶混沌系统的复杂网络混合投影同步进行研究.基于分数阶系统的稳定性理论和非线性反馈控制方法,通过设计有效的控制器,实现了不同节点的复杂网络的混合投影同步,并给出了实现投影同步的充分条件,不仅从理论上分析了该控制器可以使复杂网络系统实现投影同步,而且大量的数值模拟证明所设计控制器的正确性和有效性.     

Structure identification of uncertain general complex dynamical networks with time delay

It is well known that many real-world complex networks have various uncertain information, such as unknown or uncertain topological structure and node dynamics. The structure identification problem has theoretical and practical importance for uncertain complex dynamical networks. At the same time, time delay often appears in the state variables or coupling coefficients of various practical complex networks. This paper initiates a novel approach for simultaneously identifying the topological structure and unknown parameters of uncertain general complex networks with time delay. In particular, this method is also effective for uncertain delayed complex dynamical networks with different node dynamics. Moreover, the proposed method can be easily extended to monitor the on-line evolution of network topological structure. Finally, three representative examples are then given to verify the effectiveness of the proposed approach.     

Global synchronization of complex dynamical networks with network failures

Network failure refers to the case that parts or all of the connections in the network become disconnected. In this paper, the global synchronization of complex dynamical networks with network failures is studied based on the framework of switching system. For simplicity, assume that the network becomes totally unavailable when network failures happen and it takes a period of time to fix the network. In order to ensure the global synchronization of CDNs with network failures, the upper bounds of both the unavailability rate of the network and the frequency of network failures are obtained, respectively. Illustrated examples and the simulation results also show the effectiveness of the proposed result. Copyright © 2009 John Wiley & Sons, Ltd.     

复杂网络的脉冲同步

研究了具有有界耦合函数的不确定复杂动态网络的脉冲同步问题．根据脉冲控制的概念和脉冲微分方程的稳定性理论,我们利用一个灵活有效的脉冲控制实现了复杂动态网络的脉冲同步．最后,通过对混沌系统做网络节点的动态网络的数字模拟,验证了我们提出的脉冲控制方案的有效性和实用性．