一类多时变时延异质多智能体系统的组一致性

研究了一类由一阶和二阶智能体组成的异质多智能体系统的组一致性问题．首先,在多时变时延异质系统中设计了实现静态组一致的控制算法;其次,运用稳定性理论和线性矩阵不等式,分别给出了无时延、同时具有通信与输入时延的异质多智能体系统实现组一致性的充分条件;再次,通过求解一组可行的线性矩阵不等式,得到了输入时延的容许上界,并得出了通信时延与异质多智能体系统的组一致性无关的结论;最后,仿真结果验证了理论结果的有效性．     

对抗网络下时滞非线性多智能体系统固定时间二分一致性

本文针对一类存在输入时延的非线性多智能体系统,研究了其在结构平衡的无向符号图下的固定时间二分一致性问题.首先,本文针对智能体间相互合作与相互竞争的关系,设计了一类存在输入时延的多智能体系统固定时间分布式一致性控制协议,使得系统状态在固定时间内收敛到数值相同但符号相反的两个值,且收敛时间上界与初始状态无关.随后,利用Lyapunov稳定性理论和代数图论给出了在存在输入时延的情况下多智能体系统实现固定时间二分一致性的充分条件和收敛时间的上界值,证明了控制算法的稳定性.最后,仿真实例验证了所提固定时间二分一致性算法和理论结果的有效性.     

具有随机通信时延的二阶多智能体系统的一致性控制

研究了具有随机通信时延的二阶多智能体系统的一致性控制问题.分别讨论了具有固定拓扑结构和变化拓扑结构两种情形下二阶多智能体系统在具有随机通信时延情况下的一致性问题.通过构造Lyapunov函数的方法得到多智能体系统的时延依赖稳定判据,并以线性矩阵不等式(LMI)的形式给出了系统稳定的条件.最后,仿真和实验结果验证了研究所得结论的正确性和有效性.     

基于观测器的线性时变时滞多智能体系统一致性

针对系统状态不可测和具有通信时延的线性多智能体系统,提出一种基于观测器的一致性控制算法.设计观测器用于解决智能体状态不可测的问题,在观测器的基础上,提出一种控制协议来实现带时变时延的线性多智能体系统一致性.利用模型转换的方式将原系统转换为新的模型系统,在此基础上,构造Lyapunov-Krasovskii函数并分析系统稳定性,通过求解线性矩阵不等式获取控制器系数矩阵.最后通过Matlab数值仿真验证所提出方法的有效性.     

具有通信时延和输入时延的1阶多自主体系统的一致性问题

研究了同时具有时变通信时延和定常输入时延的1阶多自主体系统的一致性问题.假设多自主体系统的连接拓扑中各节点的输出度相等,采用变量代换将原多自主体系统的一致性问题转化为降阶系统的渐近稳定性问题.根据李亚普诺夫渐近稳定性定理以及线性矩阵不等式法,在通信时延导数信息已知和未知的情况下,分别得到了多自主体系统在静态和连通拓扑结构下渐近一致的充分条件,且该条件与通信时延和输入时延都相关.仿真结果验证了结论的有效性.     

多智能体系统实现鲁棒一致的时延相关稳定判据

考虑存在多个时变时延、有限能量扰动以及时变拓扑结构不确定等网络约束条件,给出了多智能体系统实现鲁棒一致性的时延相关稳定判据.首先,利用状态分解将原问题转化为讨论不一致向量系统的鲁棒稳定性;然后,考虑到多个时变时延和动态拓扑,采用构造Lyapunov-Krasovskii泛函的方式分析系统鲁棒稳定性,并利用自由权矩阵方法获得关于非线性矩阵不等式(NLMI)的可行解判据;最后,借鉴求解锥补问题的思想,对NLMI判据进行非线性最小化处理,以得到保守性低、易于求解的LMI稳定判据.数值实例和仿真结果均验证了所提出判据的有效性.     

具有随机多跳时变时延的多航天器协同编队姿态一致性

针对存在随机多跳时变时延的多航天器协同编队的姿态一致性问题,本文设计了可消除随机多跳时变时延影响并能够实现多航天器协同编队姿态角速度一致及姿态角有效跟踪的静态控制器.首先基于有向图论推导出领航者一跟随者误差系统的动态方程,然后通过构造合适的Lyapunov函数将误差系统调节器问题转化为了线性矩阵不等式解的存在性问题,其次通过求解线性矩阵不等式完成了协同编队姿态控制系统的静态控制器设计.理论分析表明,所设计的控制器能够有效消除随机多跳时变时延影响,实现了多航天器协同编队的姿态一致性.数值仿真验证了所提方法的正确性和有效性.     

含时变时延的多智能体的包容控制器设计

针对一类含时变通讯时延的多智能体系统,基于时滞依赖法提出了其在有向网络拓扑下的一类包容控制器设计的方法,该设计能有效地驱使多智能体系统中所有跟随者的状态渐近一致地收敛到领导者运动过程中形成的几何凸包．结合李亚普诺夫稳定性理论和线性矩阵不等式（LMI）方法,推导了多智能体系统包容控制率存在的充分条件,并将包容控制器的设计最终转化成求解线性矩阵不等式可行解的问题．结果表明,该方法对多智能体系统中的时变通讯时延具有良好的补偿效果．最后通过仿真算例验证了此方法的有效性和可行性．     

时延异构多自主体系统的群一致性分析

针对由一阶自主体和二阶自主体构成的异构多自主体系统的静态群一致性问题,分别提出了在固定连接拓扑和切换连接拓扑结构下的静态群一致性算法。通过构造Lyapunov-Krasovskii函数,得到了系统在具有相同时变通信时延的群一致性算法作用下渐近收敛群一致的充分条件,并以线性矩阵不等式表示。最后,仿真结果表明,所提算法在满足一定条件下能使时延异构多自主体系统渐近收敛群一致。     

基于分布式PID控制的时变时延多智能体系统的一致性

研究普通阶多智能体系统存在时变时延条件下的一致性问题.首先,针对系统存在时变时延的情况,结合状态反馈与PID控制提出一种一致性协议;然后,将系统状态空间分解为一致子空间和一致补子空间,采用状态空间分解法将一致性问题转化为渐近稳定问题,给出系统实现一致的充分必要条件;并确定系统的一致性函数的显示表达式;最后,构造Lyapunov-Krasovskii泛函,基于线性矩阵不等式(LMI)给出控制参数的计算方法,采用可扩充性方法降低线性矩阵不等式的计算数量.仿真结果表明,系统的结构拓扑图存在全局可达节点时,系统在所提出的协议作用下通过计算合适的PID参数和控制参数可实现一致性,通过与纯比例控制的结果对比表明,所提出的协议能够消除系统稳态误差,使系统趋于一致.     

New delay-dependent global asymptotic stability condition for Hopfield neural networks with time-varying delays

This paper deals with the global asymptotic stability problem for Hopfield neural networks with time-varying delays. By resorting to the integral inequality and constructing a Lyapunov-Krasovskii functional, a novel delay-dependent condition is established to guarantee the existence and global asymptotic stability of the unique equilibrium point for a given delayed Hopfield neural network. This criterion is expressed in terms of linear matrix inequalities （LMIs）, which can be easily checked by utilizing the recently developed algorithms for solving LMIs. Examples are provided to demonstrate the effectiveness and reduced conservatism of the proposed condition.     

Consensus networks with time-delays over finite fields

In this paper, we investigate the consensus problem in networks with time-delays over finite fields. The delays are categorised into three cases: single constant delay, multiple constant delays, and time-varying bounded delays. For all cases, some sufficient and necessary conditions for consensus are derived. Furthermore, assuming that the communication graph is strongly connected, some of the obtained necessary conditions reveal that the conditions for consensus with time-delays over finite fields depend not only on the diagonal entries but also on the off-diagonal entries, something that is intrinsically distinct from the case over real numbers (where having at least one nonzero diagonal entry is a sufficient and necessary condition to guarantee consensus). In addition, it is shown that delayed networks cannot achieve consensus when the interaction graph is a tree if the corresponding delay-free networks cannot reach consensus, which is consistent with the result over real numbers. As for average consensus, we show that it can never be achieved for delayed networks over finite fields, although it indeed can be reached under several conditions for delay-free networks over finite fields. Finally, networks with time-varying delays are discussed and one sufficient condition for consensus is presented by graph-theoretic method.     

带有时变时滞和不确定性拓扑的双积分系统的一致性

研究带有不确定性拓扑的双积分系统在有时滞的情况下的一致性问题,通过线性矩阵不等式的方法,得到一致性的充分条件。本文最大的贡献是考虑双积分系统,在有不确定性信息和时变时滞的情况下,找出控制协议使其一致。最大合适的时变时滞和不确定性可以由线性矩阵不等式得到。最后给出仿真,证明定理的有效性。     

Average consensus in networks of dynamic agents with switching topologies and multiple time-varying delays

In this paper, we discuss average consensus problem in undirected networks of dynamic agents with fixed and switching topologies as well as multiple time-varying communication delays. By employing a linear matrix inequality method, we prove that all the nodes in the network achieve average consensus asymptotically for appropriate communication delays if the network topology is connected. Particularly, several feasible linear matrix inequalities are established to determine the maximal allowable upper bound of time-varying communication delays. Numerical examples are given to demonstrate the effectiveness and the sharpness of the theoretical results.     

Finite-time stability of neutral-type neural networks with random time-varying delays

This paper is devoted to the finite-time stability analysis of neutral-type neural networks with random time-varying delays. The randomly time-varying delays are characterised by Bernoulli stochastic variable. This result can be extended to analysis and design for neutral-type neural networks with random time-varying delays. On the basis of this paper, we constructed suitable Lyapunov–Krasovskii functional together and established a set of sufficient linear matrix inequalities approach to guarantee the finite-time stability of the system concerned. By employing the Jensen's inequality, free-weighting matrix method and Wirtinger's double integral inequality, the proposed conditions are derived and two numerical examples are addressed for the effectiveness of the developed techniques.     

Semi-global Adaptive Bipartite Output Consensus of Multi-agent Systems Subject to Input Saturation and External Disturbance Under Switching Network

This paper investigates semi-global adaptive bipartite output consensus of continuous-time multi-agent systems (MASs) with input saturation and non-identical external disturbance under jointly connected switching network. An adaptive bipartite output consensus protocol of MASs is proposed by using low-gain feedback technology. It is turned out that semi-global adaptive bipartite consensus of MASs can be achieved under the protocol. Furthermore, the proposed control protocol can be applied for MASs under fixed network, and semi-global adaptive bipartite output consensus can be also achieved in this case. Finally, the simulations will verify the effectiveness of theoretical results.

     

Consensus tracking control for sampled-data second-order multi-agent systems with arbitrary weights under fixed communication topology

This paper focuses on the consensus tracking control problem of multi-agent systems (MASs) with arbitrary adjacency weights instead of traditional nonnegative weights in a sampling setting. First, unlike Lemma 4 in Hu and Hong [2007. Leader-following coordination of MASs with coupling time delays. Physica A: Statistical Mechanics and its Applications, 374(2), 853–863], for MASs with arbitrary weights, the global reachability of the leader node is just a necessary but not a necessary and sufficient condition to guarantee the positive stability of matrix H. Hence, it's urgent for us to establish some positive stability criteria of matrix H first, which is a necessary condition for MASs to achieve consensus tracking. Simultaneously, we also solve the following problems successfully: which nodes should have direct connection with the leader? What's the range size of the leader adjacency coefficients? Then, some sufficient consensus tracking control conditions are obtained for MASs without time-delays and with time-delays by using matrix analysis method and perturbation theory, respectively. Finally, numerical examples are given to illustrate the effectiveness of our results.     

具有非线性扰动和混合时滞的中立型系统的时滞依赖鲁棒稳定性

This paper concerns the delay-dependent robust stability problem of uncertain neutral systems with mixed neutral and discrete delays. Nonlinear time-varying parameter perturbations are considered. Based on the newly established integral inequalities, the neutral-delay-dependent and discrete-delay-dependent stability criterion is derived without using a fixed model transformation. The condition is presented in terms of linear matrix inequality and can be easily solved by existing convex optimization techniques. A numerical example is given to demonstrate the less conservatism of the proposed results.     

带饱和执行器的不确定时滞系统的鲁棒控制

研究了一类具有饱和执行器约束的不确定时滞系统时滞依赖型无记忆鲁棒控制问 题.所考虑的时滞系统包括时变未知但有界的不确定参数以及状态和控制的时滞项.文中应 用了Lyapunov定理以及线性矩阵不等式(LMI)方法来研究该系统的分析和综合问题,导出 了一个新的鲁棒可镇定判据和相应的无记忆鲁棒镇定控制律设计方法.所得的基于一组 LMIs的结果是与时滞相关的.