【作者】 张国庆；

【导师】 陶德馨；

【作者基本信息】 武汉理工大学 ， 机械设计及理论， 2009， 博士

【摘要】 随着交通物流行业的发展,需要提高交通运行的畅通性以及物流运输的效率,因此对智能运输系统的要求也相应提高。目前智能交通运输系统发展的趋势是将先进的信息技术、数据通讯传输技术、电子传感技术及计算机处理技术等进行有效的集成运用,对传统交通运输系统进行深入的改造,以提高系统资源的使用效率、系统安全性,减少资源的消耗和环境污染。其中涉及车辆运行信息通信的车辆间通信(IVC)系统利用了无线网络通信技术、节点定位技术等,实现车辆的智能化,可以实时地获取邻近车辆行驶信息,控制车辆行驶状态,这样一方面可以有效的控制交通阻塞,提高道路的使用率,进而降低车辆阻塞等待所带来的空气污染的环境问题,另一方面也可以预防和减少交通事故的发生,保障驾驶人员和行人的安全。基于无线自组传感网络的车辆间通信系统作为智能车辆技术应用的一个重要方面,也是目前智能运输系统技术研究的方向之一。论文在分析了国内外智能运输系统的发展现状,结合当前无线自主传感网络技术的研究,提出了基于无线传感自组网络的车辆间通信系统网络关键技术的研究。第1章,介绍了智能运输系统的国内外发展概况,以及无线自组传感网络的技术发展,说明了车辆间通信系统研究的现状及未来趋势,并提出了本文研究工作的主要内容。第2章,研究了车辆间通信系统的工作模式,分析其网络特点,并结合无线传感自组网络的相关体系结构,阐述基于无线自组传感网络的车辆间通信系统网络的主要关键技术。第3章,对无线自组织传感网络的媒体接入协议进行了分析和研究。提出无线自组织传感网络MAC层技术及其相关问题,分析研究三种现有适用于车辆间通信的MAC协议类型的特点和性能,并对其中的IEEE802.11 DCF协议进行了数学建模分析和研究,得到现有协议中的二进制退避算法在节点通信载荷较大的情况下,存在产生节点接入信道不平衡的弊端,因此提出一种基于节点使用信道时间份额评估的自适应调节退避算法,并通过仿真分析验证该算法在对节点通信吞吐量影响较小的情况下,提高了通信网络中车辆节点通信的公平性。第4章,针对车辆间通信系统中车辆分布较广,且其位置是移动变化的特点,即通信网络的网络拓扑是动态变化的特点,提出采用分簇网络通信的方式。在分析研究了无线传感自组网络的分簇原理及相关设计标准后,基于现有的分簇算法的特点,提出一种新的基于车辆节点多参数融合加权的移动自适应分簇算法,通过建模证明该算法分簇的稳定性,并通过设计程序算法类库,在NS2平台上实现算法的仿真,对该分簇算法在稳定性、分组通信等方面的性能进行了分析比较和验证。第5章,在分析了无线自组传感网络相关的路由协议的设计与分类的基础上,针对车辆间通信系统所采用的路由协议的特点和要求,研究适于车辆间通信系统的基于位置和非基于位置的两种路由协议的原理及其特点,并在此基础上提出一种采用基于车辆节点多参数融合加权分簇算法的分簇路由协议,对于路由协议中路径发现过程的传统分组转发规则进行了改进,提出了一种将车辆节点位置信息和速度信息考虑在内的车辆网络分组贪婪转发算法VPGF,该算法与传统算法相比,消除了分组转发过程中冗余的节点转发,减少了分组负载。在路由维护的过程中,提出了一种循环超时等待的算法,对IVC网络中产生的暂时性和永久性的链路中断进行区分处理,保证了分簇路由的效率。说明了该路由协议的工作原理和主要相关数据结构,并通过NS2编程仿真实现,结合车辆运动场景分析了其在多跳路由传输通信如端.端延迟、路由发现时间等方面的性能。第6章,全面总结了论文的主要研究工作和成果,并对下一步研究工作和发展方向提出了展望。更多还原

【Abstract】 With the development of modern traffic and logistics,the demand of the fluency of traffic and the efficency of logistics transportation is vital for intelligent transportation system(ITS).At present,the trend of ITS is to integrate the advanced information technology,communication technology,electronic sensor technology and computer process technology,and to improve the traditional ITS in order to enhance the efficency of resource using and system safety and to reduce the resource comsumption and environment pollution.Among ITS,the inter-vehicle communication system(IVC) concerns about the information exchange between the moving vehicles,which makes use of wireless sensor network(WSN) communication and node localization technology to realize the intelligence of vehicles,then the vehicles can acquire the information from neighbor ones and control its moving status,not only can this control the traffic jams and increase the useage rates of roads in result that decrease the pollution caused by them,but also can prevent or reduce the traffic accidents to ensure the safety of driver and pedestrian.As one of important applications of intelligent vehicle technology,the inter-vehicle communication based on the wireless sensor networks is one of the ITS research fields.This thesis analyses the development of domestic and foreign ITS technology that is combined with current wirless sensor networks research,propose the research about the IVC networks key technologies to realize the communication between vehicles.Firstly,in chapter 1,the situation of domestic and foreign ITS development is introduced,and the development of wireless sensor autonomous networks is illuminated.Then the current situation and the future trend of IVC research are proposed,the major research work in this thesis is presented.In chapter 2,basing on the analysis of the mode of inter-vehicle communication, and the features of the system structure of wireless sensor autonomous networks,the main key technologies about IVC system with wireless sensor autonomous networks are expatiated on.In chapter 3,after studying on the medium access control(MAC) protocols in wireless sensor networks,some exist problems about MAC layer technology are taken into account.The performance of the present MAC protocolos which are suitable for IVC networks is analysed and summarized.After modeling IEEE802.11 DCF protocol and studying on the work principle,an unbalance of vehicle nodes’ access wireless channel is found when the network packeload is heavy.So A new adaptive adjustment backoff algorithm basing on the evaluation of nodes’ access time is proposed.This algorithm is verified and analysed through NS2 simulation, the result shows that the algorithm can keep the fairness of nodes’ access channel with less effect on the throughput of networks.In chapter 4,the clustering communication mode is proposed to apply in IVC networks in the result of the character of dynamic changes of topology caused by vehicles’ wide distribution and movement.After analysing and studying on The WSN clustering principle and the design standard,and on the basis of the existed clustering algorithms,a new mobility adaptive clustering algorithm basing on vehicular multiple parameters weighing is presented.The stability of this clustering algorithm is verified and formulated through mathematical model and theory.Then in NS2,a new class library is designed for this algorithm,with which the algorihm is realized and simulated by programs.The simulation results indicate the stability and packet transmission etc.of this algorithm in the vehicular traffic scenario.In chapter 5,after anlysing and studing on the design method and category of routing protocols for wireless sensor autonomous networks and the characters and requirements of IVC routing protocols,The position-based and non-position-based routing protocols are studied for the IVC sytem,and the features of these tow typical routing protocols are illustrated.A new routing protocol based on clustering algorithm with vehicular multiple parameters weighinig is proposed for IVC networks,meanwhile a modified packet forward algorithm called vehicular packet greedy forwarding(VPGF) is introduced and a timeout waiting cycle algorithm in route maintenance is introduced to process the two kind of node’s disconnection respectively.The work principle and data structure are interpreted and the protocol is programmed in NS2 to simulate,the performace of routing protocol such as end-to-end delay and route discovering time etc.is analyse by the simulation result.The chapter 6 summarizes the main work and achievement of the thesis,and makes the forcast to the research work and development direction in the future.更多还原