一种有向传感器网络强栅栏覆盖算法

根据有向传感器节点感知特性,提出一种有向传感器节点模糊感知模型,以此为基础建立了模糊数据融合规则,减少网络中的不确定区域;就有向传感器网络强栅栏覆盖问题,提出一种基于粒子群的有向传感器网络强栅栏覆盖增强算法,将n维求解问题转化为一维求解,提高了算法收敛速度。仿真结果表明,对感知方向可连续调节的有向传感器网络节点,在随机部署情况下与现有算法对比,本算法对目标区域能有效的形成强栅栏覆盖,且具有较快的收敛速度,延长网络生存期。     

Wireless sensing experiments for structural vibration monitoring of offshore platform

In order to validate the feasibility of applying wireless sensing technique to structural monitoring of offshore platform, the experiment of wireless sensor network on offshore platform is presented in this paper. First, wireless sensor network and its topology structure is put forward, and the design of sensor nodes, base station, communication protocol is discussed according to self-developed wireless sensor network. Second, true offshore platform and its experimental model are introduced. Finally, wireless sensing experiment for offshore platform structure is completed and the analysis of the experimental result is given. The research shows that wireless sensor network applied to offshore platform can reflect the vibration of the structure; the sensor nodes are fixed and removed expediently, which saves the cost of signal line as well as installation time. __________ Translated from Journal of Harbin Institute of Technology, 2007, 39(2): 187–190 [译自: 哈尔滨工业大学学报]     

无线传感网络节点能效性测量优化方法

本文研究了无线传感网络节点能效性测量优化问题.给出了无线传感网络分簇式拓扑结构和节点概率检测模型,建立了网络测量覆盖率指标和通信能耗指标.遗传算法和微粒群算法在节点能效性测量优化时存在容易陷入局部最优和精度不高的缺点.将禁忌搜索算法和遗传算法结合,增强了遗传算法的全局搜索能力.仿真实验证明,采用遗传-禁忌搜索算法进行节点能效性测量优化时,网络测量覆盖率更高,通信能耗更小,优化效果更好.     

基于相长干涉的无线传感器网络数据收集

为延长无线传感器网络的生命周期,提高数据收集的可靠性,提出一种基于相长干涉的无线传感器网络低功耗可靠数据收集协议。利用时分多址技术对网络中的节点分配时隙,采用感知节点轮询发起相长干涉的网络洪泛的方式实现数据收集。针对时分多址技术需要的时间同步要求,改进现有的隐式全局时间同步算法,来保证节点轮询发起相长干涉网络洪泛的时间对齐。利用丢包重传机制来实现可靠性。仿真和测试平台实验结果均表明,能够实现几乎100%的数据收集,能量效率约为CTP的2.2倍,大幅度提高网络的生命周期、可靠性。     

高压输电监测无线传感网功率控制算法

为了延长网络生命周期,解决高压输电监测的无线传感器网络中节点能量受限问题,结合应用背景的实际特点,提出一种基于节点动态聚类的功率控制算法。该算法以高压输电监测的网络架构为基础,分析传感器节点间的空间几何位置关系,综合考虑空间几何信息与节点剩余能量,利用聚类分析方法对网络内具有相似性的节点进行动态聚类,使数据转发在类区域代表节点之间传递。同时,采用可变的功率调制技术进行数据传输。仿真结果表明,该算法能够有效地降低网络能量消耗,并延长网络的生命周期。     

Variable length dynamic addressing based on network traffic distribution in wireless sensor networks

In this paper, a novel dynamic addressing scheme for wireless sensor networks (WSNs) is proposed by using variable length coding. A WSN is typically composed of numerous tiny energy-constrained sensor nodes with limited information processing and data storage capabilities; thus, the energy-efficient strategy is the key issue in designing protocols for WSN. Traditional addressing strategies adopt flat addressing (static and uniform addresses) for sensor nodes. However, the proposed variable length dynamic addressing (VLDA) for sensor nodes is based on the fact that different nodes in the network have uneven traffic loads. Therefore, nodes with more data to receive or send are allocated with shorter addresses. Whether a node is busy or not is determined by the network traffic distribution (NTD), which is defined as the number of data packets each node has received or sent in a period of time. Sensor nodes’ energy is saved by VLDA scheme; hence, the wireless sensor network’s lifetime is extended. In the simulation, a 20% improvement has been achieved through the addressing scheme compared to traditional flat addressing.     

基于移动信标的水下无线传感器网络定位算法

针对现有水下无线传感器网络定位算法定位精度不足且无法适应水下多变的网络拓扑的问题，提出一种基于移动信标的水下无线传感器网络定位算法。首先通过RSSI测距定位和DV-Hop算法获取未知节点的大致分布情况，其次以未知节点定位覆盖率作为目标函数，采用经过自适应惯性权重和柯西-t扰动策略优化的改进秃鹰搜索算法迭代求解信标节点移动的最优位置，最后信标节点移动到最优位置再对未知节点进行重新定位。仿真结果表明,与对比算法相比，移动信标节点定位算法能有效提高未知节点定位精度，在网络拓扑变化时也能保持较高的定位精度且定位效果稳定。     

基于无线传感器网络的应急保护通道可靠性及通信性能研究

论述利用无线传感器网络构建线路纵联差动保护应急通信通道的技术方案,在考虑节点数量及其灾变损毁率情况下,提出了基于全网络通信可靠性及成本最优的节点冗余布置方法。并研究AODV路由方式下,节点通信距离、架空线路杆塔档距及转跳次数对通信延时的影响并分析了延时抖动。通过纵联差动保护数字仿真试验表明,基于无线传感器网络构建的保护通道采用节点冗余布置方法进行网络规划,在极端灾变情况下可获得较高的生存性,基本满足纵联差动保护的信息传输需求。     

基于人工免疫算法的传感器节点布置策略

针对无线传感器网络节点的应用环境特殊性,以及传统随机投放所造成的高成本,覆盖率低的问题,提出了采用免疫遗传算法对节点分布进行优化的覆盖策略,目的是在实际应用中满足网络正常运行,功能实现的条件下,尽可能以最少的节点数量达到最大的覆盖率,达到节约成本的目的,给出了算法的具体步骤。仿真结果表明：要实现97％的覆盖率,免疫遗传分布策略只需要相对较少的节点数目,相比传统的随机投放策有明显的优势。     

适用于低数据聚合率网络的能耗均衡路由算法

有效的分簇算法是实现无线传感网络能耗均衡,延长网络生存周期的关键。针对概率分簇算法随机选择簇首(CH)引起的低残余能量节点被选为簇首及迭代次数高的问题,提出一种新的半集中式分簇方法,候选簇首由前簇首推荐并通过候选簇首间竞争决定最终簇首;针对重负荷网络中的能量热区问题,引入非均匀分簇和单跳、多跳混合传输机制,提出一种适用于低数据聚合率网络的半集中式非均匀分簇(SCUC)的能耗均衡路由算法。仿真实验结果表明,SCUC算法第一个节点死亡时间较HEED算法延长111.24%,较EEUC延长74.62%。所提算法有效均衡网络能耗,延长生存周期。     

一种无线传感器节点动态采样策略

信号随着时间的变化是众多应用领域的测量要求。传统的传感器连续采样模式功耗大,不适用于无线传感器节点。文章提出一种无线传感器节点动态采样策略DSI,通过分析当前和历史采样数据引入负反馈调节的方法来动态确定传感器节点的采样间隔,以较低的采样频度、数据上传频度满足测量要求,从而降低能耗提高传感器节点寿命。仿真结果表明,与周期采样策略、SOD采样策略相比,DSI采样策略显著降低了传感器节点能耗。     

Sensor network design for fault tolerant estimation

This paper addresses the problem of fault tolerant estimation and the design of fault tolerant sensor networks. Fault tolerance is defined with respect to a given estimation objective, namely a given functional of the system state should remain observable when sensor failures occur. Redundant and minimal sensor sets are defined and organized into an automaton which contains all the subsets of sensors such that the estimation objective can be achieved. Three criteria, which evaluate the system fault tolerance with respect to sensor failures when a reconfiguration strategy is used, are introduced: (strong and weak) redundancy degrees (RD), sensor network reliability (R), and mean time to non‐observability (MTTNO). Sensor networks are designed by finding redundant sensor sets whose RD and/or R and/or MTTNO are larger than some specified values. A ship boiler example is developed for illustration. Copyright © 2004 John Wiley & Sons, Ltd.     

一种基于地址划分的无线传感网络高能效协议

针对工业应用的无线传感器网络中传感器节点相对固定、且传输的数据量一般不同的情况,为平衡各节点的能耗,延长网络生存周期,提出了一种基于地址划分的高能效协议。该协议采用了分簇结构,并且极大地简化了簇建立的过程,消除了簇头建立过程产生的网络延时。同时,该协议合理地分配了不同传感器节点的工作量,延长了网络生存周期。     

海洋监测无线传感器网络的节点数目量化分析

随着无线传感器网络技术应用于海洋监测,节点的部署及网络的性能必然受到海面环境的影响。文中引入并改进了在海洋搜救中常用的Leeway漂流模型,对随机部署在海洋表面的传感器节点运动状态进行建模。仿真分析了在不同海况下,传感器网络区域覆盖率及网络连通性受其运动状态的影响。最后,从工程应用的角度提出对于特定区域的持续监测时间这一概念,来衡量运动的传感器网络对于特定海域的监测能力,仿真并验证给出了满足该指标所要部署节点的具体数目。     

面向城市配电网的延长网络寿命路由算法

配电网智能化是提高供电可靠性和供电质量的重要手段,对配电网状态进行实时监测是实现配电网智能化的重要基础。无线传感器网络以其独有的组网灵活性、可扩展性和自组织自恢复能力,在智能配电网通信中得到了广泛关注。路由算法是无线传感器网络的网络层关键技术,算法应从整个网络系统角度,考虑网络能量的均衡使用,最终延长网络寿命。而传统的无线传感器网络因节点受能耗及路由算法限制,网络寿命较短。研究配电网应用场景下的能耗均衡路由算法成为无线传感器网络应用的一个关键问题。文中提出一种面向城市配电网的延长网络寿命的路由算法,能够平衡网络节点能量消耗,进而延长网络寿命。仿真结果表明,提出的方法能够有效延长网络寿命,适合在配电网通信中使用。     

基于ZigBee的电机故障诊断系统设计

针对目前集群现场电机故障诊断采用有线传感网络的诸多局限性,提出了一种利用ZigBee无线传感网络构建电机故障诊断系统的设计方案.设计了无线模块的硬件系统和软件系统以及上位机诊断界面,以ZigBee组建的无线传感网络实现电机的电压、电流和温度数据的采集,结合基于数学模型的电机故障诊断算法进行电机故障诊断.结果表明,该系统能准确地采集电机工作电压、电流和温度数据,并可以诊断电机的工作状态以及能对故障电机实施紧急停机操作,为工程应用提供了重要的依据.     

Theoretical and experimental study on white light interferometric sensing network with double-ring topology

A white-light interferometric fiber-optic sensing network based on the double-ring topology is demonstrated, which can be applied to the measurements of quasi-distributed strain and temperature in a smart structure. In order to increase the multiplexing capacity, decrease the measurement cost of each sensor, and improve the ability of reliability of the sensor network, a double-port interrogating technology was used. The double-ring fiber optical sensing network based on the space division multiplexing (SDM) is further developed. The low coherent multiplexing principle in the double-ring network structure is analyzed. Based on the optical path matching condition of SDM, the intensity characteristic of the interference signal in the sensor is deduced. The characteristics of the double-ring sensing network connecting 9 sensors and its property of robust resisting destruction are verified by experiments, and the results are analyzed and discussed. __________ Translated from Acta Optical Sinica, 2005, 25(6) (in Chinese)     

Hydrogen‐Gas Detection System and its Functions to Make Each Sensor Wireless

A prototype system for detecting hydrogen‐gas leaks in hydrogen filling stations was fabricated. The prototype is composed of a wireless network with 10 sensor nodes for monitoring the spatial distribution of hydrogen‐gas concentration. To make each sensor node to be driven by a battery, field‐effect transistor (FET) sensors and a microprocessor with low power consumption were used. Additionally, two functions were devised and implemented in the microprocessor in each node: one reduces the power consumption of each sensor node and the other controls the transmission to avoid communication congestion when a gas leak occurs. The use of batteries and wireless communications enables the nodes to be placed at optimal sensing locations without regard to the wiring needed with existing gas sensors. Copyright © 2008 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.     

WSAN二次分簇架构模型中实时路由策略研究

为解决无线传感器／执行器网络受到干扰导致实时性降低的问题,提出基于节点间数据传输成功率的实时分簇路由协议（RCRPSR）。通过节点一次成簇、节点二次成簇、执行器节点到sink节点路由选择,选择数据传输成功率较高的路径传输数据,降低传输失败的概率,减少数据传输时延,提高网络实时性,同时使用二次分簇架构,划分了3层网络和3种不同功能的节点,使不同功能的节点采用不同的发射功率,在保证网络连通性的同时减少能量消耗,延长了网络寿命。仿真结果表明,在网络中数据传输成功率下降时,相比传统协议,采用RCRPSR协议传输时延降低2—5倍。     

Sensor networks: an overview

Advances in hardware and wireless network technologies have created low-cost, low-power, multifunctional miniature sensor devices. These devices make up hundreds or thousands of ad hoc tiny sensor nodes spread across a geographical area. These sensor nodes collaborate among themselves to establish a sensing network. A sensor network can provide access to information anytime, anywhere by collecting, processing, analyzing and disseminating data. Thus, the network actively participates in creating a smart environment.