基于无线传感器网络的交通信息采集系统研究

实现了一种基于无线传感器网络的交通信息采集系统,采用磁阻传感器,通过测量地磁的变化来检测车辆信息,用无线传感器网络传输数据,该系统不需要大规模挖开路面铺设车辆检测器,具有安装简易,维修方便等优点。同时采用B／S结构实现了交通信息的管理,用户可以在远程终端利用浏览器在线监测,实时分析交通信息数据,并进行网络监控和维护。     

基于无线传感器网的智能交通信号控制设计

为了控制车辆在交叉路口顺畅通行,提出了一种基于无线传感器网的智能交通信号控制设计。利用传感器节点收集的交通信息,结合多Agent的协同方法,在不同的时段采用不同的路口控制模式,控制终端根据采集到的交通信息自适应地控制车辆通行时间,实现了交通信号灯的无线智能控制,从而提高车辆通行效率,实现交通信号控制的智能化、网络化。     

微波雷达辅助视频车辆分类检测器

车辆检测与分类系统是智能交通系统中的一个重要组成部分,其功能是检测路上车流量并对车辆进行分类,为道路监控和交通规划提供信息。本文提出了一种微波雷达辅助视频车辆检测与分类系统,微波雷达检测模块对经过的车辆进行检测,并触发视频分类模块结合雷达传感器信息对车辆进行分类。实验表明,该系统车辆检测率达到98％,车辆分类的准确率达到84％。     

基于DAB技术的智能交通车载终端

基于数字音频广播(DAB)技术,文章提出了一种交通诱导信息广播系统和一种车载智能终端。交通诱导信息广播系统将高速发展的广播数字化技术与城市交通智能管理相结合,是集信息采编、信息发布、信息移动接收、交通实时导航、娱乐于一体的信息处理平台;车载智能终端基于DAB技术,是用于对车辆现代化管理的设备。交通诱导信息广播系统依托移动网络可以从服务车辆上获得全球定位系统(GPS)定位信息,从而监控和跟踪车辆;车载智能终端可以接收DAB信道的实时广播、动态路况、车辆的导航路径等信息。     

基于FPGA的交通信号灯控制系统设计

为了使交通信号灯系统针对车流量变化做出有效应对,设计了一种智能交通信号灯控制系统。该系统结合道路传感器反馈的车流信息,采用有限状态机实现了交通信号灯全感应自适应控制方案,得到最优信号灯转化和时间分配。该系统采用FPGA设计,结合成都科华北路复杂交通路口车辆统计信息,对该系统进行仿真和验证。结果表明,该系统能减少17.550%的车辆平均延误时间,保障交通顺畅,提高了效率。     

基于N阶近邻路网的车辆行程时间估计模型

车联网的提出为智能交通的研究提供了新的交通信息收集技术.针对短时交通中车辆的路网行程时间估计问题,提出了基于N阶近邻的隐马尔科夫模型,利用马尔科夫性质来解决道路行程时间的前后关联性问题,同时考虑不同道路的异构性构建了N阶近邻路网模型来模拟路网间的交互影响.针对短时交通中实时数据更新的问题,提出基于道路关联性算法,并结合车联网的采集技术给出了迭代更新模型的方法.实验表明,本文提出的方法在短时交通车辆行程时间预测中精度较高,能够在车辆行进中做出实时预测.     

物联网在智能交通中的应用探究

物联网有关的技术日趋成熟,成为新的采集交通信息的思路,为交通提供了方便,为研究智能交通系统注入了活力。交通系统在城市或主要交通路口,通过交通诱导布局道路,为旅客提供交通指示的公路网,使司机选择合适的行驶道路,能为司机提供出行诱导服务,调节流量的分布,改善交通状况。基于电感式传感技术,物联网技术,计算机视觉技术,多传感器融合系统集成深度的关键技术的结合使用是使智能交通系统的关键技术。必须不断深化体制改革,解决智能交通的信息平台,也需要通过城市内部智能交通系统整体框架规划,实现路、人、车辆协同作业的终极目标。     

基于地磁传感器的无线车辆检测系统设计

针对传统车辆检测系统施工复杂、使用寿命短、安装和后期维护费用高等弊端,设计了一种基于地磁传感器的新型无线车辆检测系统。该系统主要由检测节点、上位节点、协调器三部分组成,分别负责交通信息的采集、处理和传输。系统采用易集成、灵敏度高、能耗低的地磁传感器,利用无线网络实现数据的可靠传输,具有安装简便、成本低廉、使用不受环境影响的优势。测试结果表明:该系统能实时准确地获取车流量、车速、时间占有率等交通参数,准确度高达95%,可实际应用于道路车辆检测系统。     

车辆监控管理系统的设计与实现

利用GPRS、GPS和JMF等技术开发了“车辆监控管理系统”。系统通过GPRS和JMF分别实现了车载GPS终端GPS数据的采集和站点现场交通的视频监控。系统根据GPS位置数据提取出终端的经纬度、速度和基本信息,并在电子地图上显示车辆的实时位置,同时通过视频实时查看站点路况并统计出站点对应时段的交通流。文中给出了系统主要功能实现的详细流程,该系统不但可精确定位出车辆的实际位置,且通过监控道路交通为车辆管理部门和车辆主出行提供了详细的路段车流分析,实现了车辆管理的科学化,并可有效缓解道路的交通压力。     

一种基于地感线圈传感器的车检器设计

车辆检测器对于高速路收费系统的道路管理、道路利用率及交通信息统计等都具有重要的意义。本文介绍了一种基于地感线圈传感器的车辆检测仪器，该仪器具有较强的灵活性和实时性，并且在实际应用中成本低，安装和操作简单，具有较强的通用性。     

基于REST风格的混杂感知车载网信息服务设计

实时可靠地获得全面的车载感知服务信息是车载网络发展的"瓶颈"问题。混杂感知车载网(HSVN)兼有无线传感器网络(WSN)和车载自组网(VANET)的特点,为车载用户提供了大量车载信息,是车载网络的发展趋势。表述性状态转移(REST)架构统一了资源格式和交互形式,在服务器和客户端间进行无状态服务,有利于异构问题的解决。文章基于HSVN的信息服务特征,提出一种新型车载网络框架和服务模型,能提高车载感知信息的服务交互能力;基于REST架构理念,采用HSVN中信息服务资源设计方法,为异构网络下的信息交互系统提供一种轻量化的实现途径。     

Inter Vehicle Distance Based Connectivity Aware Routing in Vehicular Adhoc Networks

Connectivity in vehicular traffic environment has witnessed significant attention due to the direct impact on the performance of most of the traffic safety applications of intelligent transport system. Various parameters such as density, speed, direction, link quality and inter vehicle distance (IVD) have been utilized for measuring connectivity. IVD has greater impact on connectivity and controls the impact of other parameters. Usage of real time IVD for measuring connectivity has not received sufficient attention in VANETs. This paper proposes IVD based connectivity aware routing (Ivd-CAR) for enhancing connectivity aware data dissemination. IVD calculation is robust and can effectively handle instantaneous GPS failure. Two localization techniques; namely, cooperative localization and Geometry based Localization are developed. Standard deviation of real time IVDs of a forwarding path is derived. Distribution of IVDs of a forwarding path is employed for estimating connectivity. Segment vehicle based next hop vehicle selection is utilized for incorporating network load, link quality and direction into consideration while selecting forwarding path. Simulations are carried out in ns2 to evaluate the performance of Ivd-CAR in realistic traffic environment. Comparative analysis of simulation results attests the superiority of Ivd-CAR to the state-of-the-art techniques: CSR and A-CAR.     

Fire Controlling Under Uncertainty in Urban Region Using Smart Vehicular Ad hoc Network

Every year thousands of urban and industrial fires occur, which leads to the destruction of infrastructure, buildings, and loss of lives. One of the reasons behind this is the delayed transmission of information to the fire station and the nearer hospitals for ambulance service as the transmission of information is dependent on observer at the location where the fire is caught and cellular network. This paper proposed an automated routing protocol for the urban vehicular ad-hoc network to send the information from the location where the fire is caught to the nearest fire stations and hospitals with optimum service time. This transmission of information involves Road Side Unit (RSU) at the junction and the vehicles present in the transmission path. Selection of route to transmit faulty vehicle information from the RSU to the required faulty vehicle is based on a parameter called path value. The computation of path value is done by the attributes such as expected End To End (E2E) delay, the shortest distance to destination, the density of vehicle between the junctions, and attenuation. From the current junction, the selection of the next junction is based on minimum path value. The proposed routing protocol considers the performance parameters such as E2E delay, total service time (TST), number of network fragments or network gaps, number of hops, and attenuation for the propagation path for the evaluation of the proposed methodology. The proposed routing algorithm is implemented through OmNet++ and SUMO. Results obtained for the proposed routing protocol is compared with three existing VANET protocols (GSR, A-STAR, and ARP) in terms of End To End delay, number of hops, number of vehicular gaps, and Total Service Time (TST).

     

基于GSM的车载图像监控系统

介绍一种采用图像压缩与GSM数字通信技术的车载图像监控系统。该监控系统的车载设备利用数字信号处理器和现场可编程门阵列对运营车辆的乘客完成拍照、图像压缩和存储,并在必要时通过GSM网络向系统控制中心传送乘客经压缩的彩色图像和车辆特征等信息。监控系统的控制中心还可以对运营车辆内部状况进行远程监控。该系统不仅能够提供犯罪嫌疑人的图像,还可以提供适当精度的车辆定位信息。     

地面移动目标被动探测最优路径规划

提出了一种机载传感器对地面移动目标被动测量的最优路径规划方法。该方法考虑目标状态估计精度,采用扩展卡尔曼滤波算法进行传感器量测信息滤波,进而实时计算传感器目标探测跟踪的信息矩阵。在此基础上,考虑目标被动探测的环境及飞行器性能约束,以目标信息阵等为指标,进行被动探测最优路径规划,实现地面移动目标探测。最后,进行了该被动探测最优路径规划算法的仿真研究。研究结果表明,所提出的被动探测最优路径规划算法能够快速、有效地完成最优被动探测路径的规划计算。     

Vector quantization for license-plate location and image coding

License-plate location in sensor images plays an important role in vehicle identification for automated transport systems (ATS). This paper presents a novel method based on vector quantization (VQ) to process vehicle images. The proposed method makes it possible to perform superior picture compression for archival purposes and to support effective location at the same time. As compared with classical approaches, VQ encoding can give some hints about the contents of image regions; such additional information can be exploited to boost location performance. The VQ system can be trained by way of examples; this gives the advantages of adaptiveness and on-field tuning. The approach has been tested in a real industrial application and included satisfactorily in a complete ATS for vehicle identification     

车载移动异构无线网络架构及关键技术

传统的车辆通信网络通常只是针对于公路计费等用途设计的封闭式通信网络,新近的发展使得车辆支持车间自主通信从而互通安全信息。但是由于在网络架构方面的缺陷,现有的系统只能对高速行驶中的车辆提供局部区域内的信息交互,无法实现车辆与智能交通控制中心进行实时数据服务和接入宽带无线网络。文章提出了基于车辆环境下无线接入（WAVE）（IEEE802.11p）和全球微波接入互操作性（WiMAX）（IEEE802.16e）融合的车载移动异构无线网络体系,建立了新型车载异构网络通信架构及体系模型,并分别对WAVE网络中的多信道自适应协调机制和分布式多信道调度算法和基于移动预测的路由及服务质量、WiMAX网络中的群组切换机制和两级资源调度等关键技术进行了研究和探讨。     

An efficient adaptive intelligent routing system for multi‐intersections

With the rapid development of wireless technologies and the growing emphasis on vehicle safety, many vehicular ad hoc network applications have been extensively used. This study attempts to use vehicular ad hoc network technologies for autonomous driving to improve and reduce traffic congestion and vehicle waiting time. Therefore, this study proposes an adaptively intelligent routing system, which uses V2V communications to increase vehicle speed, allows vehicles to communicate with traffic control systems, arranges appropriate vehicle routes based on queuing theory, and uses traffic signals for information exchange. The timing of traffic signals is decided according to road traffic density. To decrease vehicle waiting time at intersections, every vehicle's speed is adjusted based on the distance between the vehicle and the traffic signals. In the simulation, automated vehicles and a more realistic car‐following model are taken into consideration and vehicle speeds are regulated based on speed limits and safe following distance on most roads. The simulation result reveals that our proposed adaptively intelligent routing system outperforms periodic system in average vehicle speed and average waiting time at both single and double cross intersections. Copyright © 2016 John Wiley & Sons, Ltd.     

A Position-Based Clustering Technique for Ad Hoc Intervehicle Communication

Intervehicle communication is a key technique of intelligent transport systems. Ad hoc networking in the vehicular environment was investigated intensively. This paper proposes a new clustering technique for large multihop vehicular ad hoc networks. The cluster structure is determined by the geographic position of nodes and the priorities associated with the vehicle traffic information. Each cluster elects one node as its cluster head. The cluster size is controlled by a predefined maximum distance between a cluster head and its members. Clusters are independently controlled and dynamically reconfigured as nodes move. This paper presents the stability of the proposed cluster structure, and communication overhead for maintaining the structure and connectivity in an application context. The simulation is performed with comparative studies using CORSIM and NS-2 simulators.