基于事件驱动和神经网络的无线传感网络数据融合算法研究

为降低突发事件监测的无线传感器网络(WSN)的能量消耗和数据冗余,设计并实现一种基于事件驱动的动态分簇BP神经网络数据融合算法(EBPDF)。其中动态成簇以及簇头选举过程基于事件严重程度和节点剩余能量,簇的生命周期和簇的覆盖范围根据事件紧急程度和节点剩余能量进行动态调整。同时,为减少网络通信量,将神经网络层次结构与WSN的簇结构相结合,在动态形成的簇结构中应用三层神经网络模型,通过神经网络算法从采集到的大量原始数据中提取出少量特征值,并发送到汇聚节点,从而延长网络生命周期,降低数据传输的冗余度。理论仿真实验证明,与LEACH算法相比,该算法既能有效降低网络通信流量,又能减少节点通信次数。     

一种考虑先验估计误差相关性的快速DUIF 算法

针对稀疏无线传感器网络(WSN) 中加权平均一致分布式无迹信息滤波(DUIF) 算法估计次优和滤波效率较低的问题, 提出一种考虑先验估计误差相关性的快速DUIF 算法. 采用加权统计线性回归(WSLR) 方法线性化观测模型, 以节点共享信息作为平均一致性算法输入, 从而在极大后验估计中引入先验估计交互协方差信息; 设计最优通信连接边权值并自适应修正状态加权矩阵, 提高平均一致性算法收敛速率. 仿真实验结果表明, 所提出的算法能够有效应用于稀疏WSN目标跟踪.

     

一种非线性动态自适应的Agent联盟生产算法

代理(Agent)联盟是对无线传感器网络WSN(Wireless Sensor Network)进行管理的重要手段.引入粒子群算法PSO(Particle Swarm Optimization)并对其进行改进,使PSO的参数具有非线性动态自适应性.将改进的PSO用于求解Agent联盟生成问题,并针对WSN的特性设计了一种效益函数用于评价联盟的效益.采用基于非线性动态自适应PSO的Agent联盟生成算法,在联盟生成初期搜索范围较广,搜索后期在局部挖掘上表现出良好的性能.实验证明在解决Agent联盟生成问题中,基于PSO的算法在稳定性上优于其他算法,基于改进PSO的联盟生成算法可以加大搜索空间,更快的收敛到最优解,且该算法可以同时生成多个Agent联盟,支持并行多任务环境下的Agent联盟求解.     

6LoWPAN无线心电传感网络架构与RPL优化仿真

阐述了通过心电采集节点、6LoWPAN边界路由器构建无线传感网络,实现了无线传感器网络(WSN)与IPV6网络之间的通信;针对RPI网络协议中的Trickle算法机制导致选择次优链路,影响网络路由的可靠性和稳定性问题,提出了优化方案;开展了仿真测试和优化后的网络性能指标分析;测试结果和分析表明,6LoWPAN无线传感网络不仅可以完成WSN与外部IPv6网络之间的连接承载数据收发,并且在对Trickle算法优化之后,对提高网络性能有较高影响.     

无线传感器网络中分布式多跳路由算法研究

在对无线传感器网络路由算法深入研究的基础上,设计出了一种完全分布式的、能量有效的无线传感器网络多跳路由算法,主要内容包括:(1)在成簇方面,给出了一种基于时间延迟机制的无线传感器网络成簇算法CHTD,解决了相同能量节点在产生簇头时的碰撞问题。并通过仿真验证了CHTD成簇算法比LEACH和目前已有的基于定时器的成簇算法TB-LEACH对网络性能有明显改善;(2)在簇头数据传输方面,给出CHTD-M簇间多跳路由算法。该算法将网络中均匀分布的簇头构造成一棵路由树,通过多跳传输的方式减少直接与基站通信的簇头节点数量。最后对整体算法进行仿真,实验结果表明,CHTD-M把节约网络能量和保持网络负载平衡很好的结合起来,显著地延长了网络的生命周期。     

Admissible consensus for networked singular multi-agent systems with communication delays

This study concerns the admissible consensus problem for networked singular multi-agent systems with communication delays and agents described by general singular systems. Only the information of outputs is available through the network. An observer-based networked predictive control scheme (NPCS) is employed to compensate for the communication delays actively. Based on NPCS and dynamic compensator (dynamic output feedback), a novel protocol is proposed. Based on graph, algebra and singular system theory, the necessary and sufficient conditions are given to guarantee existence of the proposed protocol. The conditions depend on the topologies of singular multi-agent systems and the structure properties of each agent dynamics. Moreover, a consensus algorithm is provided to design the predictive protocol. A numerical example demonstrates the effectiveness of compensation for networked delays.     

An agent-assisted QoS-based routing algorithm for wireless sensor networks

Existing routing algorithms are not effective in supporting the dynamic characteristics of wireless sensor networks (WSNs) and cannot ensure sufficient quality of service in WSN applications. This paper proposes a novel agent-assisted QoS-based routing algorithm for wireless sensor networks. In the proposed algorithm, the synthetic QoS of WSNs is chosen as the adaptive value of a Particle Swarm Optimization algorithm to improve the overall performance of network. Intelligent software agents are used to monitor changes in network topology, network communication flow, and each node's routing state. These agents can then participate in network routing and network maintenance. Experiment results show that the proposed algorithm can ensure better quality of service in wireless sensor networks compared with traditional algorithms.     

Adaptive second-order consensus of networked mobile agents with nonlinear dynamics

We investigate second-order consensus of multiple nonlinear dynamical mobile agents with a virtual leader in a dynamic proximity network. We assume that only a small fraction of agents in the group have access to the information about the position and velocity of the virtual leader through, for example, certain pre-designed communication mechanism such as wireless broadcasting or sensing. To avoid fragmentation, we propose a connectivity-preserving second-order consensus algorithm. Under the assumption that the initial network is connected, we introduce local adaptation strategies for both the weights on the velocity navigational feedback and the velocity coupling strengths that enable all agents to synchronize with the virtual leader even when only one agent is informed, without requiring any knowledge of the agent dynamics. We finally provide some convincing simulation results to illustrate the theoretical results.     

面向网络攻击下弹性均值趋同的智能体群组编队

本文研究通信范围有限的智能体群组编队问题,探索网络攻击下多智能体系统弹性均值趋同控制策略.现有的工作表明,多智能体系统可通过维持一个所谓r–鲁棒的通信网络,实现分布式弹性趋同控制器的设计.然而,传统的方法中只有当单个智能体的通信范围足够大时,才能使网络满足r–鲁棒这一特定条件.本文利用智能体可移动的特性放宽了对通信范围...     

Secure Consensus Control for Multi-Agent Systems With Attacks and Communication Delays

This paper addresses the consensus problem for nonlinear multi-agent systems suffering from attacks and communication delays. The network studied in this paper consists of two types of agents, namely, loyal agents and attack agents. The loyal agents update their states based on delayed state information exchanged with their neighbors. Meanwhile, the attack agents can strategically send messages with wrong values, or collude with other attack agents to disrupt the correct operation of the system. We design a novel delay robust secure consensus (DRSC) algorithm according to the neighboring nodes' delayed information. Convergence analysis of the system under the protocol designed is provided by using Lyapunov-Krasovskii stability theory and Barbalat-like argument approach. Finally, an example and simulation results are presented to demonstrate the effectiveness of the algorithm.      

无线传感器网络地理协同通信算法

针对无线传感器网络能量有效性和协同通信节点选取问题,提出基于位置的无线传感器网络协同通信算法(CCABL).该算法通过距离参数选取协同节点及其成员节点,并引入数据融合和分簇思想.协同节点融合成员节点数据,采用F/R(forward/reverse)协同通信传输数据.理论分析和NS2仿真验证表明,与数据融合算法和LEACH分簇算法相比,CCABL算法不仅有效地提高了能量有效性,而且节点能量消耗更加均衡,网络生存期长,同时算法实现简单,控制开销低.     

一种无线传感器网络中自主选择簇头的聚类算法

在无线传感网络中,传感器节点要定期向基站发送收集的数据。为了支持数据汇总,通过高效的网络组织将节点划分成若干簇。在这种类型的系统中,随着簇头的轮转,每个簇中的簇头选择方法是最具有挑战性的问题,有效的簇头选择算法可以提高网络的续航时间,并减少在WSN中的节点之间的通信开销。提出一个簇内民主方式选举算法来选择簇中的节点作为簇头,用MatLab对算法进行仿真,证明该算法的性能可以有效改善网络的性能。     

基于BP神经网络的多变量PID解耦控制

基于神经网络的智能PID控制策略，以经典的PID控制理论为基础，并通过具有多变量解耦控制自学习功能的神经网络参数整定来实现。本文给出了网络的结构和算法，示出了一组二元变量强耦合时变系统的实时仿真结果。通过计算机仿真证明，基于神经网络的PID控制具有良好的自学习和自适应解耦控制能力。该系统融解耦器和控制器于一体，易于实现，适用于非线性多变量系统的解耦控制。它使解耦后的系统具有较好的动态和静态性能，特别是当根据BP控制规律确定了网络连接权系数的初值时，还能使系统参数快速收敛。     

一种基于WSN信号强度的位置指纹定位方法

随着近年来网络与通信技术的大发展,人们对各种定位信息的需求也日益增大。虽然在室外定位中,GPS技术可以满足人们较高的定位需求,但其在室内的定位效果却令人难以接受。而近些年来无线传感网络（WSN）的发展,恰好为我们提供了一种成本低、实施简便、定位精度高的室内定位方法。文中提出了一种基于无线信号强度的室内定位算法,阐述了其定位原理,并以ZigBee无线网络为基础搭建了基于该算法原理的室内定位系统。最后,通过在实际环境中对该定位系统的测试,得出其最大定位偏差达到3m以内,平均定位偏差达到2m以内。     

A Distributed Drafting Algorithm for Load Balancing

It is desirable for the load in a distributed system to be balanced evenly. A dynamic process migration protocol is needed in order to achieve load balancing in a user transparent manner. A distributed algorthim for load balancing which is network topology independent is proposed in this paper. Different network topologies and low-level communications protocols affect the choice of only some system design parameters. The "drafting" algorithm attempts to compromise two contradictory goals: maximize the processor utilization and minimize the communication overhead. The main objective of this paper is to describe the dynamic process migration protocol based on the proposed drafting algorithm. A sample distributed system is used to further illustrate the drafting algorithm and to show how to define system design parameters. The system performance is measured by simulation experiments based on the sample system.     

HLA仿真系统中Lookahead的分析与动态调整策略

在HLA仿真系统中，Lookahead是影响系统性能的重要参量，对Lookahead的管理也是实现邦元程序的重要内容。采用时间分段的方式重新定义HLA仿真系统中的Lookahead，很好地解决了仿真运行中时戳增量改变较大的问题。在此基础上提出的Lookahead动态调整算法考虑了邦元程序对要接收事件的经验值，可以有效提高系统运行性能，协助邦元程序设计。     

Event‐Based Consensus Controller for Linear Multi‐Agent Systems Over Directed Communication Topologies: A Co‐Design Approach

The paper addresses the distributed event‐triggered consensus problem in directed topologies for multi‐agent systems (MAS) with general linear dynamic agents. A co‐design approach is proposed to determine parameters of the consensus controller and its event‐triggered mechanism (ETM), simultaneously. This approach guarantees asymptotic stability along with decreasing data transmission among agents. In the proposed event‐based consensus controller, each agent broadcasts data to the neighbors only at its own triggering instants; this differs from previous studies in which continuous data streams among agents were required. Furthermore, the proposed control law is based on the piecewise constant functions of the measurement values, which are updated at triggering instants. In this case the control scheme decreases the communication network usage, energy consumption, and wear of the actuator. As a result, it facilitates distributed implementation of the proposed consensus controller for real‐world applications. A theorem is proved to outline sufficient conditions to guarantee the asymptotic stability of the closed‐loop system with the event‐based consensus controller. Another theorem is also proved to show the Zeno behavior exclusion. As a case study, the proposed event‐based controller is applied for a diving consensus problem to illustrate the effectiveness of the method.     

基于博弈论的无线传感器网络簇间路由选择算法

针对无线传感器网络(WSN)中,网络覆盖范围大,但传感器节点通信范围有限,长距离传输容易造成数据丢失的问题,提出了一种基于博弈论的无线传感器网络簇间路由算法,通过建立以网络服务质量(QoS)和节点剩余能量为效用函数的博弈模型,并求解其纳什均衡来解决以上问题。仿真结果表明：所提出的博弈模型在优化网络服务质量、降低节点能耗的同时,延长了整个网络的生存时间。     

基于参数不敏感设计的网络拥塞控制算法

本文提出了一种新颖的主动队列管理(active queue management,AQM)策略一间隔随机早期检测(interval random earlv detection,IRED).与传统的RED机制不同,IRED的参数设计中,平均队长的门限值一最小阈值和最大阈值从固定不变的单值,变为了一个阈值区间.相对于RED的单值固定阈值的设计,IRED的适应能力和鲁棒性得到增强,在大多数的网络环境下能够保持良好的性能,特别是在网络状态出现波动和突变时,其性能比传统的AQM算法更佳.本文进一步采用了TCP-AQM的动态模型分析了使用IRED控制器的拥塞控制系统的稳定性,分析了系统的稳定裕度,并给出了稳定裕度与控制增益的关系式,从而提出了一种根据期望稳定裕度来设计阈值区间的系统化方法.最后.在NS-2仿真平台上,通过与RED和Gentle-RED种算法比较,证明IRED优越性,特别是在变负载的网络环境下的良好性能.