A Switch Agent for Wireless Sensor Nodes with Dual Interfaces: Implementation and Evaluation

Data generation in wireless sensor networks could be bursty as it is dictated by the presence or absence of events of interest that generate these data. While conventional sensor nodes possessed only one radio interface, next generation sensor nodes are expected to have two （possibly more） radio interfaces, each with different ranges, capacities, and power consumptions. Equipping sensor nodes with dual radios has its own benefits and can be quite useful in handling bursty traffic while at the same time satisfying the application＇s delivery requirements. In this paper, we propose an adaptive interface switch agent that intelligently selects the interface to be used for data transmission at a sensor node based on the data burst length or end-to-end delay while taking into consideration power consumption and throughput. The proposed work generalizes earlier works in this area to enable both the source nodes and intermediate data forwarding nodes to initiate the activation of high power radios so that they can be utilized to a higher degree for converge-cast communication. We have performed extensive simulations with sensor nodes containing both IEEE 802.15.4 and IEEE 802.11 compatible radios. Our simulation results indicate that the switch agent yields throughput, delay, and packet delivery ratio comparable to the higher bandwidth interface alone, without incurring much energy wastage.

Consensus of high-order dynamic multi-agent systems with switching topology and time-varying delays

This paper studies the consensus problems for a group of agents with switching topology and time-varying communication delays, where the dynamics of agents is modeled as a high-order integrator. A linear distributed consensus protocol is proposed, which only depends on the agent＇s own information and its neighbors＇ partial information. By introducing a decomposition of the state vector and performing a state space transformation, the closed-loop dynamics of the multi-agent system is converted into two decoupled subsystems. Based on the decoupled subsystems, some sufficient conditions for the convergence to consensus are established, which provide the upper bounds on the admissible communication delays. Also, the explicit expression of the consensus state is derived. Moreover, the results on the consensus seeking of the group of high-order agents have been extended to a network of agents with dynamics modeled as a completely controllable linear time-invariant system. It is proved that the convergence to consensus of this network is equivalent to that of the group of high-order agents. Finally, some numerical examples are given to demonstrate the effectiveness of the main results.

Multi-agent consensus with time-varying delays and switching topologies

The consensus problems of multi-agents with time-varying delays and switching topologies are studied. First, assume that an agent receives state information from its neighbors with fixed communication delays and processes its own state information with time-varying self-delay respectively. The state time-delay feedback is introduced into the existing consensus protocol to begenerate an improved protocol. Then a sufficient condition is derived which can make the system with time-varying self-delays achieve the consensus. On this basis, a specific form of consensus equilibrium influenced by the initial states of agents, time-delays and state feedback intensity is figured out. In addition, the multi-agent consensus is considered with time-varying topologies. Finally, simulations are presented to il ustrate the validity of theoretical results.

Consensus problem of second-order multi-agent systems with time-varying communication delay and switching topology

Leader-following stationary consensus problem is investigated for the second-order multi-agent systems with timevarying communication delay and switching topology. Based on Lyapunov-Krasovskii functional and Lyapunov-Razumikhin functions respectively, consensus criterions in the form of linear matrix inequality （LMI） are obtained for the system with time-varying communication delays under static interconnection topology con- verging to the leader＇s states. Moreover, the delay-dependent consensus criterion in the form of LMI is also obtained for the system with time-invariant communication delay and switching topologies by constructing Lyapunov-Krasovskii functional. Numerical simulations present the correctness of the results.

Hybrid-triggered consensus for multi-agent systems with time-delays,uncertain switching topologies, and stochastic cyber-attacks

We propose a new approach to discuss the consensus problem of multi-agent systems with time-varying delayed control inputs, switching topologies, and stochastic cyber-attacks under hybrid-triggered mechanism.A Bernoulli variable is used to describe the hybrid-triggered scheme, which is introduced to alleviate the burden of the network.The mathematical model of the closed-loop control system is established by taking the influences of time-varying delayed control inputs,switching topologies, and stochastic cyber-attacks into account under the hybrid-triggered scheme.A theorem as the main result is given to make the system consistent based on the theory of Lyapunov stability and linear matrix inequality.Markov jumps with uncertain rates of transitions are applied to describe the switch of topologies.Finally, a simulation example demonstrates the feasibility of the theory in this paper.

H_∞ couple-group consensus of stochastic multi-agent systems with fixed and Markovian switching communication topologies

The paper addresses the issue of H_∞ couple-group consensus for a class of discrete-time stochastic multi-agent systems via output-feedback control. Both fixed and Markovian switching communication topologies are considered. By employing linear transformations, the closed-loop systems are converted into reduced-order systems and the H_∞ couplegroup consensus issue under consideration is changed into a stochastic H_∞ control problem. New conditions for the mean-square asymptotic stability and H_∞ performance of the reduced-order systems are proposed. On the basis of these conditions, constructive approaches for the design of the output-feedback control protocols are developed for the fixed communication topology and the Markovian switching communication topologies, respectively. Finally, two numerical examples are given to illustrate the applicability of the present design approaches.

Time-varying formation for general linear multi-agent systems via distributed event-triggered control under switching topologies

This paper investigates the time-varying formation problem for general linear multi-agent systems using distributed event-triggered control strategy.Different from the previous works,to achieve the desired time-varying formation,a distributed control scheme is designed in an event-triggered way,in which for each agent the controller is triggered only at its own event times.The interaction topology among agents is assumed to be switching.The common Lyapunov function as well as Riccati inequality is applied to solve the time-varying formation problem.Moreover,the Zeno behavior of triggering time sequences can be excluded for each agent.Finally,a simulation example is presented to illustrate the effectiveness of the theoretical results.

基于分层邻域选择的切换拓扑多智能体系统一致性协议

在切换拓扑的多智能体系统中,针对高低密度信息减弱一致性的问题,提出了一种基于分层邻域选择算法(Layered Neighbor Selection,LNS),该算法对智能体的邻域进行层次划分,从每层中选取具有代表性的邻居智能体进行通信、状态更新和状态演化,然后设计了层次调整策略和层次融合策略来加快收敛速度,最后设计了分层邻域选择一致性协议,且给出了层数对收敛的影响。现有的一致性协议,收敛效果受限于特定密度范围,受不同密度的影响较大,而本文提出的协议能适应不同密度范围,并在系统稳定的条件下提升收敛速度,且通过李雅普诺夫函数法证明了一致性协议的稳定性。最后通过仿真实验,并与几种一致性协议进行比较,验证了所设计的一致性协议能有效加快系统收敛速度。

路由选择的多Agent系统模型

路由选择是电信网的关键技术之一 ,其优劣直接影响着网络的接通率和负载平衡程度 .我国长途电信网的接通率只有 45 %左右 ,链路的利用率又仅为 30 %— 40 % .据介绍 ,若其接通率提高一个百分点 ,收益可达 10亿元 .随着业务量的飞速增长 ,路由选择问题日益突出 .文中在分析目前程控交换机所使用的路由选择方法的不足的基础上 ,提出基于多 Agent系统和神经网络预测的智能路由策略 ,介绍系统模型和选择方法 .

切换拓扑下多智能体时变编队控制方法

针对通信存在测量噪声和链路频繁断开下的多智能体时变编队稳定控制问题,基于期望编队状态、智能体自身状态和通信拓扑,提出一种切换拓扑下多智能体时变编队控制方法。首先,通过矩阵替换对系统进行降维处理。然后,应用随机微分方程理论和Lyapunov稳定性定理推导出编队系统在普通切换和随机切换下稳定的充要条件以及编队收敛指标。最后,在四个智能体构成的编队和四个备用拓扑的仿真条件下,验证了所提方法可有效保证多智能编队在切换拓扑下的稳定性。相较于普通切换拓扑,随机切换拓扑能更快地将编队误差收敛至10^(-2)以内,效率提高约34.4%。同时编队收敛指标也证实了这一结论,且编队的精确性以及应用范围也要优于普通切换拓扑。

基于多Agent的倒闸操作票生成系统

A gen t和多A gen t系统已经成为计算机科学和分布式人工智能研究的一个重要方向。该文重点介绍了基于多A gen t技术的操作票生成系统的模型的建立,研究了通过A gen t选择意图模型来实现操作任务的规划,以及对单个A gen t的推理机制和知识库中的符号化描述,并讨论了A gen t自学习及多A gen t之间的交互通信等问题。开发实现基于多A gen t变电站倒闸操作票生成系统,在某变电站得到良好的应用。实践表明,基于多A gen t系统能大大提高工作效率和准确度,特别是基于A gen t选择意图模型来实现操作任务的规划更能适应外界环境的变化。

考虑可切换拓扑的网络化多智能体快速原型开发系统

智能制造已经成为推动工业4.0革命的核心动力。随着信息技术手段的不断升级,智能制造不仅要求生产过程本身的自动化及智能化,更对相关开发系统的灵活性、可扩展性和可实验性提出了极高的要求。多智能体系统(MAS)凭借其自治与协同兼备的优良特性,在智能制造的推进中展现出了巨大的应用潜力。然而,传统的多智能体系统开发模式通常有着拓扑结构固定、响应速度慢及实验验证困难等客观难题,这限制了其进一步的发展。针对这一难题,提出一套基于可切换拓扑的网络化多智能体(NMAS)快速原型开发系统,帮助开发者轻松获得目标网络化多智能体的快速原型。所构建的多智能体快速原型开发系统可实现拓扑结构的灵活切换,从而适应不同生产场景的需求。通过引入先进的通信协议及协同算法,能够保障开发系统的高效通信、快速响应及用户交互,从而实现对原型开发系统的快速验证及优化。该系统与智能制造相结合,不仅能够提高生产过程的灵活性及可扩展性,还能极大程度缩短产品的研发周期,全面降低生产成本。

基于Agent的网络遥操作机器人系统控制研究

为了充分发挥智能机器人的自主性和人的主观能动性,实现通过网络遥操作非结构化环境下的智能机器人,提出了一种基于Agent的网络遥操作机器人控制系统结构,分析了控制系统中各部分的功能,给出了系统中各个Agent的实现方法。该控制方法已通过仿人形机器人的遥操作控制实验得到了验证。

基于多Agent系统的微电网运行模式平滑切换

采用了分层结构的多Agent系统以实现微电网运行模式的平滑切换,该系统含上层协调Agent和下层执行级Agent。执行级Agent包含孤岛检测Agent、控制Agent和并网检测Agent,执行级Agent完成自身功能的同时,实时地与协调级Agent沟通协调。协调级Agent通过和大电网、执行级Agent之间的通信、协调,及时地对执行级Agent发出控制信号,使微电网能够在并网模式与孤岛模式之间平滑切换。提出了一种基于V/f控制的预同步控制方法,能够实现孤岛模式到预同步,同时实现微电网的平滑并网。

多Agent的MPLS流量工程自适应策略研究

MPLS流量工程自适应问题是国内外比较关注的热点问题,论文提出了基于多Agent实现流量工程自适应的方案,来实现功能自动化。论文首先描述了agent实现自适应的策略,然后定义了TE-agent的概念,定义了MPLS流量工程隧道的操作模型和属性并论证了可行性,最后以示例来说明其实现的过程。

ATM交换机SNMP Agent的研究与实现

在ATM交换机开发过程中 ,SNMPAgent的开发起着核心作用 ,它是连接硬件平台、单板、软件系统、信令的桥梁。结合ATM交换机项目 ,使用目前国际上先进的开发工具 ,本文系统介绍了ATM交换机SNMPAgent开发的各个环节、开发步骤和具体的实现方法 。

固定和切换拓扑下多智能体系统二分容错状态一致性研究

针对具有传感器故障的连续时间线性领导-跟随多智能体系统,研究了固定和切换拓扑下的二分容错状态一致性问题。首先,考虑不存在传感器故障的情况,提出了一种基于状态反馈的分布式二分一致性控制协议;其次,考虑存在传感器故障和状态不可测的情况,根据邻居交互信息构造新型分布式状态和故障观测器,并提出了基于输出反馈的分布式二分容错一致性控制协议;最后,进一步考虑通信拓扑发生切换的情况,提出了一种基于观测器的输出反馈二分容错一致性控制协议。理论分析和仿真算例均验证了不同情况下提出的分布式控制策略能够消除传感器故障带来的不良影响,同时,可实现预期的二分状态一致。

随机拓扑下离散多智能体事件触发一致性

针对离散时间多智能体跟踪不稳定的问题,本文研究离散多智能体系统的事件触发一致性控制问题,通过马尔可夫跳变拓扑结构实现各智能体间的信息交互,设计了一种基于动态响应的事件触发条件,给出了马尔可夫跳变控制协议,构造带有转移概率的离散Lyapunov函数,得到所有智能体是均方一致性的充分条件。数值算例验证了所提方法的有效性,证明了本结论可用于解决随机拓扑下离散多智能体的跟踪不一致问题。

Markov切换拓扑下离散多智能体系统滑模一致性控制

针对具有Markov切换拓扑的离散多智能体系统,研究了其在滑模控制下的均方领导跟随一致性问题。通过引入Markov切换拓扑,描述了智能体之间的随机信息交互。采用一致性误差定义了与随机切换拓扑相关的滑模面。根据理想准滑动模态条件得到了等效控制律,并将离散多智能体系统的一致性问题转化为领导跟随误差系统的稳定性问题;利用Lyapunov函数的构造和矩阵理论最终给出了离散滑动模态均方领导跟随一致性的充分条件,并给出了控制增益的设计方法。然后利用趋近律原理给出了一种离散时间滑模控制器,实现了跟随误差能够在有限时间内到达所定义的滑模面区域内。如何处理部分转移概率未知的Markov切换拓扑和设计与随机切换拓扑相关的滑模面是本文的两个难点。最后通过一个数值算例验证了所提方法的有效性。