面向突发事件的车载网络拓扑建模及道路信息传播关键技术研究

Recently, nature disaster emergencies have happened frequently, which have caused many traffic accidents. Thus, Human’s travel efficiency was greatly reduced, even more their life were threatened. Since there is few knowledge about road information propagation schemes under the nature disaster emergency situations, the modeling for unstable vehicle ad hoc networks (VANETs) as well as the information propagation methods for road information toward the emergencies situations not only is of important theoretical significance, but also has important engineering value. In this research, based on the vehicle ad hoc networks environment, the research will be proposed with these following steps: ①considering the disadvantages of the current mathematic probability model for the VANET topology, a fuzzy VANET topology model will be proposed based on fuzzy logic language; ②an adaptive store-carry-forward(SCF) routing protocol will be designed for both extreme sparse and dense road vehicle conditions when nature disaster happened. According to the SCF routing protocol, the message will be propagated by different ways under different road vehicles conditions. Besides, a next-hop selection scheme also will be proposed based on the time-distance space headway among vehicle nodes;③a hybrid channel control scheme will be used for transmitting different kinds of road information, that is to say, the Radio Frequency channel will be combined with the visible light channel to transmit different road information with a distributed way, this hybrid channel model will be used to enlarge the available communication channel , and broke the limitations of 75MHz in VANET with the Dedicated Short Range Communications (DSRC) standard. In general, this work will give out a completed road information propagation method toward the emergency cases, and provide theoretical support for road safety related applications in VANET.

近年来，自然界中各类突发事件的出现导致交通事故频发，严重降低了人们的出行效率，甚至威胁到人身安全。鉴于当前缺乏有效的针对突发事件下道路信息传播机制的研究，围绕突发事件下道路车载网络拓扑变化规律探索和道路信息传播机制研究的相关工作将具有重要的理论和应用价值。本研究中，基于车联网环境，将展开：①抛弃现有的移动车载网络拓扑的概率型数学模型，采用“模糊性”量化语言，构建 “模糊性”车载网络拓扑模型；②将针对因突发事件导致的道路极端车辆稀疏分布情况，提出自适应路由方案，实现可根据车辆稀疏分布情况自适应调节信息传播的路由方式，并提出基于时空标准的下一跳节点选择策略；③探索新型可复用通信信道，采用射频信道与可视光信道复用的方式，有望突破DSRC中75MHz带宽的局限，并实现多种道路信息的分布式分区域传播。通过本研究，力争形成完整的突发事件下道路信息传播分析方法，为车联网在道路安全方面的应用提供理论支撑。

道路突发事件可引起道路交通处于瘫痪状态，致使各种道路信息传播中断。面向突发事件的道路信息传播关键技术等问题的研究，力求在突发状态下，实现道路信息的快速、准确的传播。针对此，项目组获得的主要成果如下：. 首先，研究了突发事件下车载网络拓扑建模的问题，获得了基于模糊控制原理的“模糊化”网络拓扑模型，该模型包含三个输入因素和一个输出因素，并制定了一系列模糊控制规则；其次，研究了应急信息传播时下一跳节点路由选择的问题，提出了基于模糊控制的下一跳节点选择、基于时空车头距的下一跳选择、以及基于platoon的下一跳节点选择等方法；最后，研究了光信道与无线射频信道复用、拓宽了可用信道的带宽，采用光信道和无线射频信道复用的形式实现了多类型的信息传播。. 共发表论文14篇，其中英文期刊论文1篇，EI检索的会议论文13篇（包括2篇待EI收录）；申请软件著作权3项，培养3名研究生获得硕士学位，已全面完成计划任务。本项目的研究成果可为道路安全信息传播及道路安全行驶等方面的实际应用提供一定的理论和技术支持。