Target Detection in Three-Dimension Sensor Networks Based on Clifford Algebra

The three-dimensional sensor networks are supposed to be deployed for many applications. So it is signifi-cant to do research on the problems of coverage and target detection in three-dimensional sensor networks. In this paper, we introduced Clifford algebra in 3D Euclidean space, developed the coverage model of 3D sensor networks based on Clifford algebra, and proposed a method for detecting target moving. With Clif-ford Spinor, calculating the target moving formulation is easier than traditional methods in sensor node’s coverage area.

A Three-Dimensional Range-Free Localization Algorithm Based on Mobile Beacons for Wireless Sensor Networks

In wireless sensor networks （WSNs） the position information of individual nodes is a matter of vital importance because allows the implementation of necessary network functions such as routing, querying and other applications. The objective of this paper is to propose an algorithm of three-dimensional distributed range-free localization for WSNs, using a mobile beacon （MB） equipped with a rotary and tilting directional antenna. This algorithm, denominated as the three-dimensional azimuthally defined area localization algorithm （3D- ADAL）, is executed in each sensor node and is based only on the analysis of the information received from the MB, therefore is energy efficient and contributes to extend the lifetime of the sensor network. Additionally the proposed algorithm has the advantage of being simple and economical. The simulation results show that the proposed algorithm is a practical, effective and accurate method for a three-dimensional location of sensor nodes in a WSN.

HetGNN-3D:基于异构图神经网络的3D目标检测优化模型

3D感知是自动驾驶场景的核心问题,传感器融合可以综合利用激光雷达和摄像机的优点以达到更高的3D目标检测准确率.传感器融合涉及点云到图像对准问题,预先对传感器标定可以得到点到图像位置的投影关系,然而这种对准方式受传感器相对位置偏移与采集时间偏移影响而在干扰下对模型产生负面影响.针对该问题,本文把场景中实体在各个传感器下的不同表达作为不同对象,以对象为节点建立包含两类节点与三类边的异构图描述该场景,并提出了基于该异构图的3D目标检测优化模型HetGNN-3D.该模型通过图结构捕获对象间潜在联系并找到点云对象节点与图像对象节点间对应关系,从而减弱干扰带来的影响.HetGNN-3D包含图初始化、消息传递、图读出三大模块.图初始化模块使用基于点云的3D目标检测模型的输出和基于图像的2D目标检测模型的输出建立对象级异构图.消息传递模块针对异构图特性分类聚合与更新消息.图读出包含用于对象关系预测的边读出与属于同一实体的对象子图读出,然后基于对象子图得到3D目标检测结果.在nuScenes数据集的实验表明,HetGNN-3D有效融合点云信息与图像信息优化了3D目标检测结果,此外,基于对象级异构图的边关系预测使融合过程与预先标定得到的传感器映射矩阵解耦合,从而提升了融合模型的容错性与鲁棒性.

A Void Avoidance Scheme for Grid-Based Multipath Routing in Underwater Wireless Sensor Networks

This work proposes a geographic routing protocol for UWSNs based on the construction of a 3D virtual grid structure, called Void-Avoidance Grid-based Multipath Position-based Routing (VA-GMPR). It consists of two main components, the multipath routing scheme and the grid-based void avoidance (GVA) mechanism for handling routing holes. The multipath routing scheme adopts node-disjoint routes from the source to the sink in order to enhance network reliability and load balancing. While the GVA mechanism handles the problem of holes in 3D virtual grid structure based on three techniques: Hole bypass, path diversion, and path backtracking. The performance evaluation of the VA-GMPR protocol was compared to a recently proposed grid-based routing protocol for UWSNs, called Energy-efficient Multipath Geographic Grid-based Routing (EMGGR). The results showed that the VA-GMPR protocol outperformed the EMGGR protocol in terms of packet delivery ratio, and end-to end-delay. However, the results also showed that the VA-GMPR protocol exhibited higher energy consumption compared to EMGGR.

基于WSN与Web3D的信息机房环境三维仿真监测

针对信息机房环境监测的需求,设计并实现了一种基于无线传感网和Web3D的信息机房三维仿真监测系统。利用JN5148组成的无线传感网进行数据的采集和通信,通过ARM11实现嵌入式数据网关,采用Web3D技术实现实景的三维仿真监测,解决了传统方式不易扩展、互操作性差的缺点。实际应用表明,该系统适用于网络的运维管理工作,便于扩展和管理。

一种能耗鲁棒性权衡的3D-WSN拓扑控制算法

该文针对3维无线传感器网络(3D-WSN)需兼顾能耗与鲁棒性的问题,建立了能耗鲁棒性权衡模型,利用Lyapunov稳定性理论证明了稳定平衡解的存在。进而提出了一种基于该模型的拓扑控制算法(TCA-TM),获得了3维无线传感器网络的优化拓扑。实验结果表明,该拓扑结构不仅能够满足网络鲁棒性要求,还能有效地均衡网络能耗,延长网络生命期。

粒子群APIS-3D算法在三维传感网络中的定位研究

无线传感网络三维空间定位算法大都是将二维向量转化为三维空间,其原理与平面定位基本相同,实现简单,没有考虑节点移动对定位偏差的影响。提出一种基于粒子群APIS-3D定位算法,利用粒子模拟节点移动状态,并根据RSSI信号指纹的动态反馈过程建立适应度函数,通过定位球体交集区域重心以计算节点坐标。仿真实验证明,新算法在保持抽样概率不变情况下,对移动节点平均定位偏差在2.42%以内,能很好满足工程应用要求。

固定节点3D网格部署的水下传感器网络分簇路由算法

水下传感器网络是应用于水下通信的重要传感器网络技术。提出了基于固定节点3D网格部署的水下无线传感器网络分簇算法,设计了3D网格的编址和分簇方法,实现了基于地址分配的节点定位,构建了算法的能耗分析模型。采用MATLAB完成了算法的性能仿真,对比了DS-VBF、IAR和GEDAR 3个算法的平均数据传输延迟和网络生存时间(TTL)。实验结果表明,此算法的平均数据传输延迟较短,可明显提高UWSNS的生存时间。

快速3D-MSPIHT视频编码算法

多媒体传感器节点的处理能力、存储能力和通信能力相对较弱,给视频编码传输带来了极大的挑战。提出了一种改进的3维等级树集分割(3D-MSPIHT)的视频编码方法,将等级树集分割(SPIHT)算法予以改进并推广应用于3维视频编码中,该算法采用提升小波进行3维子带分解,通过改进的根和分割方法实现对系数重排序,保证更多重要的信息更早地编码于比特流中;同时采用无链表的编码结构,不需要进行复杂繁重的运动估计和补偿,实现了较少的内存和能量消耗,能够提供较好服务质量(QoS)。实验结果表明,此方案优于3D-SPIHT算法,低比特率情况下尤为突出;与H.264等编码方案相比,在图像质量基本相同的情况下,编码速度提高了11.5～11.8倍。

3D有向多媒体传感器网络视觉覆盖率优化

3D多媒体传感器网络中的视觉信息的监测更为复杂多变,在感知模型设定、连通覆盖等方面均不同于2D,使得视觉覆盖面临许多新的问题.本文研究3D有向多媒体传感器网络视觉覆盖率优化机制.首先提出3D感知空间近似模型,对节点感知模型进行实例化,通过空间近似方法降低计算复杂度.在此基础上,设计空间冗余最小化的感知方向调整算法,提高节点视域利用率,进而优化视觉覆盖率和有向目标鉴别率.仿真实验结果表明,视觉覆盖率和目标鉴别率分别在随机分布的基础上提高了82.5%和27.6%,即利用该算法能够提高视觉覆盖率和目标鉴别率.

Design of 3D Space Following Positioning System Based on ZigBee

The research on positioning system and spatial alignment is a big topic. In this paper, we proposed a design (that) studies two issues. One is the study of range positioning algorithm based on ZigBee communication system. The other one is spatial alignment platform which is controlled with two servos. Hardware and software control system was realized, which also consists of two parts, ZigBee network positioning system and automatic orientation platform.

基于浮标的3D水声传感器网络节点定位

节点位置的确定是水下无线传感器网络的应用基础。为了提高节点定位精度并延长网络生命周期,提出一种使用海面浮标节点作为参考节点的水下传感器网络节点定位算法。仿真结果表明该方法提高了节点定位的精度,并在一定程度上减少了能耗。

A New 3D Wireless Directional Sensing Model and Coverage Enhancement Algorithm

Coverage control for each sensor is based on a 2D directional sensing model in directional sensor networks conventionally. But the 2D model cannot accurately characterize the real environment. In order to solve this problem,a new 3D directional sensor model and coverage enhancement algorithm is proposed. We can adjust the pitch angle and deviation angle to enhance the coverage rate. And the coverage enhancement algorithm is based on an improved gravitational search algorithm. In this paper the two improved strategies of GSA are directional mutation strategy and individual evolution strategy. A set of simulations show that our coverage enhancement algorithm has a good performance to improve the coverage rate of the wireless directional sensor network on different number of nodes,different virtual angles and different sensing radius.

Architecture Design of an Integrated Communication and Broadcasting Network

Due to the power limitation of nodes in wire-less sensor networks (WSNs), how to maximize network lifetime has become a critical issue for deployment of WSNs. Although several schemes have been proposed for 2D WSNs, few for 3D WSNs are known. In this paper, we present a scheme to maximize network lifetime for 3D WSNs through balancing energy consumption, as an extension of the existing scheme for 2D WSNs proposed recently [1]. Same as [1], we formulate the energy consumption balancing problem as an problem of optimal distribution of transmitting data by combining the techniques of sphere-corona based network division, mixed-routing and data aggregation. We first present a Tiled-block based routing scheme in order to balance energy consumption among nodes in each sphere-corona. Then we design an algorithm to compute the optimal distribution ratio of transmitting data between direct and hop-by-hop transmission, with the purpose of balancing energy consumption among nodes across different sphere-coronas. We show maximizing network lifetime through computing the optimal number of sphere-coronas. Afterwards a energy consumption balanced data collecting protocol (ECBDC) is designed and a solution to extend ECBDC to largescale WSNs is also presented. Simulaiton results show that ECBDC is superior to conventional direct and multihop transmission schemes in network lifetime.

毫米波雷达与相机两级融合的3D目标检测方法研究

多传感器融合是当前自动驾驶领域感知系统的重点。针对在恶劣复杂天气场景下目标以及远距离小目标检测效果差的问题,提出一种基于毫米波雷达与相机两级融合的3D目标检测方法。该方法先在数据层将毫米波雷达条码化处理与相机信息融合建立三通道图像,然后输入到加入注意力机制的特征提取网络中进行初级检测;在特征层采取截锥体数据关联的方式,将毫米波雷达信息与初级检测结果进行关联,进一步提升检测精度。实验结果显示,在大型自动驾驶数据集nuScenes下的mini集对融合网络进行评估,相比基准网络Centerfusion,平均精度(mAP)提升了1.09%,检测指标(NDS)提升了1.21%。

移动传感网络在3D场景中的最小耗能移动策略

结合3D场景中移动传感网络的能耗模型和视距概率传感器模型,研究了在满足目标覆盖要求时移动传感网络的最小能耗移动问题,分析了穷举法、贪心算法和模拟退火算法各自的优劣。模拟实验结果表明,近似最优解可以在可接受的时间内得到。

基于虚拟力的水下传感器监控反潜策略研究

近年来无人潜航器对海上重要目标的威胁逐渐增大,体积小、噪声低、行动隐蔽的特点使其很难被发现。为此提出了一个基于虚拟力的传感器监控网络构建算法,通过将三维地形分割,得到面积最小的垂直切面。在该切面上部署传感器,定义了传感器所受重力、互相之间斥力以及边界斥力,在合力的作用下达到平衡状态时完成传感器部署。理论分析和仿真验证表明,提出的算法对复杂地形适应性强,能够根据覆盖率要求得到对应的传感器部署策略,与传统方法相比更灵活,且通过与VFOPCA算法比较,其能耗更低收敛更快。该研究对监控无人潜航器的侵入有指导借鉴意义。

基于多传感器网络的三维虚拟场景人机交互研究

过去的人机交互技术大多采用触摸屏、键盘、操纵杆等,这种交互技术没有三维虚拟场景的体验特点,导致人机交互准确率不高。因此,提出基于多传感器网络的三维虚拟场景人机交互研究。需要构建多传感器网络素材库,根据素材库中的数据导入三维虚拟场景,调整细节参数,从而设计出三维虚拟场景。通过客户端结构进行信息交互,执行安全控制的指令,再修改场景数据参数,成功采集了三维虚拟场景下人机交互的数据。通过设计三维虚拟场景及采集三维虚拟场景人机交互数据,同时采用多传感器网络融合机制,实现了三维虚拟场景人机交互。进行仿真对比实验,表明所研究的三维虚拟场景人机交互准确率始终控制在95%以上,更具有研究价值。

无线传感网非测距三维节点定位算法

采用DV-hop算法中距离矢量跳数和平均跳距计算方法,依据几何学原理,引入位置估算偏差值,利用加权质心算法进行位置估算,设计了一种新的无线传感网非测距三维节点定位算法,给出了该算法设计的理论依据和实现步骤.仿真结果表明,作为非测距定位算法,在设定的三维空间中,随机放置40个锚结点,能对所有节点进行定位,并可以达到0.4以下的较高精度,而且通信开销相比于二维定位方法增幅不大。

三维水下移动传感网多目标有向路径覆盖增强机制研究

水下传感网中实现多个移动目标的协同追踪任是一个技术难题,针对这个问题论文提出了一种分布式的多目标有向路径覆盖增强算法。在实际的三维水下传感网中,水下传感器节点会随着水流运动而移动,被追踪的目标具有自主行动能力。假设移动规律遵从Meandering Current Mobility模型,多个运动目标沿着基于概率的Random Walk移动模型轨迹运动。在论文提出的算法中,覆盖运动路径的传感器节点通过两跳邻居节点范围内的水下传感器节点协同决策来实现最大化路径覆盖,通过调整水下传感器节点自身的有向覆盖方向达到多目标轨迹路径有向覆盖率平均值最大,并使多目标轨迹路径有向覆盖率标准方差尽量小。最后论文通过MATLAB软件仿真来验证分布式覆盖增强算法的有效性,能够显著提高多个移动目标的路径覆盖率。