水下移动无线传感器网络研究综述

水下移动传感器网络是水下机器人与水下传感器网络的结合,解决了传统水下监控网络存在的无法自动实现节点投放与回收,容易存在监测盲区以及不能动态组网等问题,按照自下而上的体系结构,对水下移动传感器网络的研究内容及发展方向进行了归纳阐述,包括水下节点设计、节点互联和动态组网,即点、线、面的层次结构;着重分析了节点移动特性对水下传感器网络的影响及相应的解决方法.虽然水下移动传感器网络的研究面临很多挑战,但它必将具有广阔的应用前景.     

水下移动无线传感器网络拓扑

水下移动无线传感器网络是当今世界各国的研究热点之一. 水下复杂环境以及传感器节点移动特性使得水 下移动无线传感器网络拓扑具备了动态演化性, 同时, 水声通信也对水下移动无线传感器网络的可靠性产生了一定 影响. 首先归纳分析水下移动无线传感器网络国内外的研究现状及进展, 并剖析了水声通信对水下移动无线传感器 网络拓扑的影响; 然后凝炼出3 个科学问题, 重点论述了拓扑生成、拓扑愈合及拓扑优化; 最后对未来研究方向进行 了展望, 以期为该领域的深入研究提供清晰的思路.

     

刚性驱动水下传感器节点自组织布置

水下传感器网络可用于海洋资源勘测、污染监测和战术监视等领域,已成为无线传感器网络的研究热点.在开放式动态的水下环境中传感器节点如何自主调整部署位置以达到高的网络覆盖度和连通性,从而保证最优的监测质量是一个关键问题.该文引入刚性理论,定义了节点域的“刚性-覆盖值”作为水下传感器节点所处位置的评价指标,并基于此设计了刚性驱动的节点移动策略,从而构建了完整的节点自组织布置方法.理论分析和仿真实验结果表明该水下传感器节点自组织布置方法可以使网络演化出优良的覆盖度和连通性,并且具有分布式可实现、收敛速度快、鲁棒性强的优点.     

水下移动无线传感器网络研究综述

水下移动传感器网络是水下机器人与水下传感器网络的结合,解决了传统水下监控网络存在的无法自动实现节点投放与回收,容易存在监测盲区以及不能动态组网等问题.按照自下而上的体系结构,对水下移动传感器网络的研究内容及发展方向进行了归纳阐述,包括水下节点设计,节点互联和动态组网,即点,线,面的层次结构,着重分析了节点移动特性对水下传感器网络的影响及相应的解决方法.虽然水下移动传感器网络的研究面临很多挑战,但它必将具有广阔的应用前景.

     

基于无线传感网络的水质在线移动监测系统

针对静态离线水质监测方法存在采样误差大、监测频次低、监测数据分散以及无法实时反馈水质状况的连续动态变化等问题,研发了基于无线传感网络的水质在线移动监测系统.该系统由水下监测器、浮标节点和可视化软件组成.水下监测器模仿金枪鱼外观设计,内部装备水质传感器(温度、pH、浊度和电导率等)用于获取水质参数信息;浮标节点采用太阳能供电方式,负责接收、处理、中继及转发来自多个水下监测器的数据;多个水下监测器之间,水下监测器与浮标节点之间采用170 MHz无线射频模块或水声通信,浮标节点与岸边基站采用ZigBee通信;可视化软件包括上位机与移动终端.本系统的实施解决了传统人工取样监测的局限性,实现水域任意点的水质在线监测.     

基于K-means和SOM的水下传感器数据采集方法

随着海洋资源勘探和海洋污染物监控工作的开展,水文数据的监测和采集等已经成为重要的研究方向.其中,水下无线传感器网络在水文数据采集过程中起着举足轻重的作用.本文研究的是水下无线传感器二维监测网络模型中,传感器节点数据采集的问题,其设计方法是通过自组织映射(Self-organizing mapping,SOM)对传感器节...     

基于无线传感器网络的湿地水环境远程实时监测系统关键技术研究

对湿地水环境监测技术的研究现状与进展进行了概述.提出了基于无线传感器网络的湿地水环境远程实时监测系统的系统框架,重点讨论了基于自然光水下照射强度的浊度软测量技术、面向湿地水环境监测的三维无线传感器网络的节点覆盖算法、传感器节点健康状况诊断算法和小水域子网的网内数据聚合点的选举算法等关键问题.     

一种基于顺序博弈的UWSNs覆盖控制算法

近年来,人们对海洋资源愈加重视,水下无线传感器网络在海洋数据监测、海洋军事、辅助导航等方面的应用引起了广泛关注。一个良好的水下无线传感器网络覆盖控制,首先能够降低覆盖冗余,优化网络空间资源的配置;其次可以减少节点的能耗、降低网络的成本并延长节点的生命周期,使水下无线传感器网络可以更好地完成目标水域环境感知任务。提出了一种基于顺序博弈的水下无线传感器网络覆盖控制方法,用于优化水下无线传感器网络的覆盖控制,期望能够降低节点的能耗,均衡节点之间的能量,最终实现延长网络的生命周期的目标。仿真实验表明,该算法能够提高网络覆盖率和延长网络生命周期。     

基于遗传算法的无线传感器网络巡航覆盖最小移动节点数研究

被监测环境的状态可以使用无线传感器网络的有效感知.本文使用无线传感器网络巡航覆盖模型实现了建筑能效监测过程.为降低基于无线传感器网络巡航覆盖模型的数据采集系统构造和维护成本并降低系统复杂度,采用MTSP问题对无线感器网络巡航覆盖最小移动节点数问题建模,提出了无线感器网络巡航覆盖最小移动节点数快速求解算法并使用遗传算法实现了快速求解算法.实验结果表明,本文提出的方法快速有效,而基于遗传算法的快速求解算法的实现可以快速确定无线感器网络巡航覆盖最小移动节点数上界.     

基于水平集的围猎式水下传感器节点布置研究

水下传感器网络作为一种探索和开发海洋的新方法,在人类不易接触的水下区域的探测和监测中发挥着重要作用,是无线传感器网络领域研究的热点.在水下空间中传感器节点如何自主调整位置实现对"兴趣域"的覆盖和监视是一个重要课题.该文引入水平集理论LSM,提出了一种基于水平集的围猎式水下传感器节点布置方法.在该方法中网关节点根据传感器...     

Topology control algorithm for underwater wireless sensor networks using GPS-free mobile sensor nodes

Underwater wireless sensor networks (UWSNs) have been developed for underwater applications, such as resource exploration, pollution monitoring, and tactical surveillance. The topology control techniques of UWSNs and terrestrial wireless sensor networks are significantly different because of the particularity of underwater environments and acoustic communication, such as mobility pattern, propagation delay and energy consumption. Due to multifarious factors of underwater environments, node mobility becomes a non-negligible issue. However, GPS may not be feasible because of the limitations of satellite coverage or obstructions in adverse underwater environments. In particular, anchored sensor nodes towed by wires are prone to offset around their static positions, causing each node to move within a spherical crown surface (spherical crown mobility pattern). Nevertheless, most previous studies have not focused on this specific mobility pattern. In the current paper, a mobility model for UWSNs nodes is constructed, and three representative topology control objectives are attained. A distributed radius determination algorithm is designed for the mobility-based topology control problem. Results of theoretic analysis prove that the proposed algorithm is convergent, and it has preferable approximate ratios and polynomial complexity. Performance of the algorithm is analyzed through simulation experiments, which indicate a well-constructed topology. Every objective can still be upgraded without the dynamic location information of mobile nodes.     

Key distribution scheme for peer-to-peer communication in mobile underwater wireless sensor networks

Wireless Sensor Networks (WSN) consist of small battery-limited devices called sensor nodes. The communication between sensor nodes is a type of peer-to-peer communication, since each node has the same capability and role. One of the recent application areas of these nodes is underwater sensing. Communication in Underwater Wireless Sensor Networks (UWSN) is challenging since radio frequencies cannot be used. Instead acoustic waves, which cause extra challenges, are used in UWSN. Since UWSNs are deployed in hostile environment, nodes can be captured by an adversary. In order to secure UWSNs, key distribution problem must be addressed. Moreover, UWSNs are inherently mobile since the nodes may be drifted in the sea. In this paper, we propose a key distribution model which is applied for two group mobility models, namely nomadic mobility model and meandering mobility model. In both schemes hierarchical structure is used and communication is handled via well-known Blom’s key distribution scheme. Our simulation results show that mobility causes some temporary decreases in the connectivity, but our schemes help to heal the connectivity performance in time. Moreover, our schemes show good resiliency performance such that capture of some nodes by an adversary only causes very small amount of links between uncaptured nodes to be compromised.     

一种集中式水下无线传感器网跨层调度协议

分析了水下无线传感器网络（WSNs）中单链路发射功率和距离与频率的关系,提出一种跨层的集中式调度方法,AP（access point）在网络中通过广播信标的形式收集估计各节点的时延和距离信息,在MAC层考虑水下链路延迟特点,对各链路进行调度减少冲突;节点在物理层通过自适应地改变节点发射功率和发射频率,减少能耗.仿真结果表明：所提方案在节省系统能量消耗的同时,能够减少碰撞,提高系统吞吐量.     

水下传感器网络中的多路径路由技术研究

水下声信道是一种复杂信道,由于各方面因素影响,在数据传输过程中,水下传感器网络数据链路层会有可能产生随机中断.研究了一种虚拟汇聚节点的多路径水下传感器网络路由技术,在随机布设的传感器节点中选取了缓存节点,并创建了局部的汇聚节点,通过多路径的路由技术,有效减少了网络吞吐率受链路中断的影响,并且避免了汇聚节点处的数据冲突.通过网络的冗余性,增强了网络稳定性、鲁棒性.     

Pair-Wise Collision-Based Underwater Time Synchronization

Time synchronization is a critical issue for Underwater Wireless Sensor Networks (UWSN). Although numerous time synchronization algorithms have been proposed for terrestrial wireless sensor networks, none of them could be applied to UWSN directly. This is because underwater time synchronization offers two fundamental challenges compared with terrestrial wireless sensor networks, i.e., (1) long propagation delay and (2) sensor node mobility. We propose a novel time synchronization approach called Coll-Sync to address the above challenging problems, which is a pair-wise collision-based time synchronization scheme for mobile underwater acoustic sensor networks. Coll-Sync adopts collision and packet meetings in a long propagation process to eliminate the effect of node mobility. In this paper, we indicate that collision and packet meetings contain highly useful information that can be leveraged to improve time synchronization. Through comprehensive experiments, we show that our proposed Coll-Sync greatly outperforms existing time synchronization schemes in both precision and energy saving.     

无线网络中的一种基于小世界模型的路由协议

最近,利用节点的移动性提升网络系统性能的方法引起了不少关注。这些方法已经被运用于包括移动Adhoc网络（MANET）、无线传感网络（WSN）和容忍延时网络（DTN）在内的一些新兴网络中,他们都认为节点是随机或者可控移动的。为了达到优化或平衡包括延时、平均中继节点数目和移动距离在内的一些度量参数的目的,本文提出了一种基于于小世界模型的路由协议（SWR）。通过分析,该协议只有多对数数量级的中继节点,大大减少了报文传输过程中中继节点的数量。文中定义了短链接与长链接的概念,其中每一节点与其最邻近的节点之间存在“短”链接,而与其他遵循桌一概率分布的节点间存在着“长”链接。短链接通常是无线链接,而长链接通常是利用移动节点来实现的。本文在网络规模、使用数据搭乘者、多重长链接和等待移动节点时间方面进行了分析。通过仿真结果,我们对各方面性能进行了评估。     

Mutual-information based weighted fusion for target tracking in underwater wireless sensor networks

Underwater wireless sensor networks (UWSNs) can provide a promising solution to underwater target tracking. Due to limited energy and bandwidth resources, only a small number of nodes are selected to track a target at each interval. Because all measurements are fused together to provide information in a fusion center, fusion weights of all selected nodes may affect the performance of target tracking. As far as we know, almost all existing tracking schemes neglect this problem. We study a weighted fusion scheme for target tracking in UWSNs. First, because the mutual information (MI) between a node’s measurement and the target state can quantify target information provided by the node, it is calculated to determine proper fusion weights. Second, we design a novel multi-sensor weighted particle filter (MSWPF) using fusion weights determined by MI. Third, we present a local node selection scheme based on posterior Cramer-Rao lower bound (PCRLB) to improve tracking efficiency. Finally, simulation results are presented to verify the performance improvement of our scheme with proper fusion weights.     

UWSNs中基于深度的抑制空洞路由优化算法

针对传统的水下无线传感器网络(UWSNs)的位置路由存在路由空洞问题,提出了基于深度的抑制空洞路由(DSVR)的UWSNs路由协议.DSVR协议通过融合跳数、物理距离和邻居数多个指标决策路由.为了提高通信可靠和缓解路由空洞,DSVR协议选择具有最小跳数路径、最少邻居数的节点作为下一跳转发节点.同时,DSVR协议利用定时器抑制冗余数据包.仿真结果表明:提出的DSVR协议能有效地提高数据包传递率,并降低端到端传输时延以及能耗.     

移动社交网络中基于网络中心度的链路预测方法*

移动社交网络中的链路预测是指通过已知的网络节点以及移动社交网络结构等信息预测网络中尚未产生连边的两个节点之间产生链接的可能性。基于网络中心度的思想,提出一种适用于移动社交网络的链路预测算法。在该算法中,根据节点网络中心度和共同邻居数来计算两个节点的相似性指标,两个节点的共同邻居数越多、共同邻居的网络中心度越高,则两个节点的相似度越高。另外,由于移动社交网络的动态性特征,还将考虑时间因素对预测结果的影响。将该方法与其他4种常用的链路预测方法进行比较,实验结果显示所提方法要优于其他方法。