车联网驾驶安全和交通效率典型应用的建模与性能分析研究

发布时间：2018-11-01 14:03

【摘要】：车联网已经在学术界被广泛研究,在工业领域也逐年开始应用,是物联网技术在智能交通系统大环境下的典型应用。车联网在保护环境、节约燃料资源、提高车辆驾驶安全性和日常出行效率等方面也有着重大的作用。目前,智能交通系统中的许多协议和应用无法大规模地在实际条件下进行试验和测试,这使得这些协议真正付诸应用面临着困难,如果想要获得这些协议和应用在实际运行过程中的一些性能指标则需要依靠仿真试验的模拟或理论建模计算。本文将对车联网中保障驾驶安全类的典型应用—分布式环境通知消息和提升交通效率类的典型应用—中心导航进行建模与性能分析研究。分布式环境通知消息是一个由事件驱动的协议,它通过“车对车”和“车对基础设施”通信技术在车辆间传播,使得车辆能够提前感知到危险情况的存在。分布式环境通知消息在车辆间的传播情况取决于它的发送端工作情况(如节点的发射功率、消息的发送频率)、消息要到达的区域类型(如矩形目的区域、圆形目的区域和椭圆形目的区域)、信道竞争情况(如隐藏终端和暴露终端、负载饱和还是不饱和)以及性能指标(如包成功交付率、时间延迟、吞吐率以及信道利用率)。本文建立了理论模型去分析这些参数对分布式环境通知消息的性能指标的影响并且做了数值实验分别计算在饱和以及不饱和情况下不同目的区域中性能指标的值。作为智能交通系统中提升交通效率的一项重要应用,车载导航系统被使用的越来越广泛。近年来,中心导航这一应用也受到了广泛关注,尤其是“车对基础设施”通信技术的出现,使得车辆可以实时上传其自身位置信息给导航计算中心。导航计算中心可以根据实时的路况信息、车流信息、利用最新道路状况为用户进行导航,从而达到缓解交通压力的效果。由于大量的车载导航用户同时向计算中心发送导航请求以及共享其位置信息,这会产生一定的通信方面的延迟,导航计算中心也会耗费较大的时间延迟来处理这种多目标计算问题。本文以中心导航这一应用为例,重点研究时间延迟这一项在不同条件下(如车辆密度、目的节点入度、交叉路口数量以及从导航起点到终点的距离等)对这一应用的结果即导航结果的准确率、导航车辆运行速度及时间的影响。
[Abstract]:Car networking has been widely studied in academic circles and has been applied in the industrial field year by year. It is a typical application of Internet of things technology in the environment of intelligent transportation system (its). Car networking also plays an important role in protecting environment, saving fuel resources, improving vehicle driving safety and daily travel efficiency. At present, many protocols and applications in its cannot be tested and tested on a large scale under actual conditions, which makes it difficult to implement these protocols. If we want to obtain these protocols and some performance indicators of the application in the actual running process, we need to rely on the simulation of simulation experiments or theoretical modeling calculation. In this paper, the modeling and performance analysis of central navigation, a typical application of distributed environment notification message and traffic efficiency class, is carried out. Distributed environmental notification message is an event-driven protocol, which propagates between vehicles through "vehicle-to-vehicle" and "vehicle-to-infrastructure" communication technology, which enables vehicles to perceive the presence of dangerous situations in advance. The spread of a distributed environment notification message between vehicles depends on how its sender works (such as the transmit power of the node, the frequency of the message being sent), the type of region the message is to reach (such as the rectangular destination area, for example, the Circular and elliptical destination regions, channel competition (such as hidden terminals and exposed terminals, load saturation or unsaturated), and performance indicators (such as packet delivery rate, time delay, throughput and channel utilization). In this paper, a theoretical model is established to analyze the effect of these parameters on the performance indexes of distributed environment notification messages, and numerical experiments are performed to calculate the values of performance indicators in different target regions under saturation and unsaturated conditions, respectively. As an important application of intelligent transportation system to improve traffic efficiency, vehicle navigation system is more and more widely used. In recent years, the application of central navigation has been paid more and more attention, especially the emergence of "vehicle-to-infrastructure" communication technology, which enables vehicles to upload their own position information to the navigation computing center in real time. According to the real-time information of road condition and traffic flow, the navigation computing center can use the latest road condition to navigate for the user, so as to reduce the traffic pressure. Because a large number of on-board navigation users simultaneously send navigation requests to the computer center and share their location information, this will result in a certain delay in communication. The navigation computing center will also spend a lot of time to deal with this multi-objective computing problem. Taking the application of central navigation as an example, this paper focuses on the study of time delay under different conditions (such as vehicle density, destination node entry, etc.) The number of intersections and the distance from the navigation starting point to the end point have an effect on the accuracy of navigation results and the speed and time of navigation vehicles.
【学位授予单位】：吉林大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：U495;TN929.5

【相似文献】