基于Wi-Fi Direct的车路协同数据分发技术

发布时间：2018-01-15 17:08

本文关键词：基于Wi-Fi Direct的车路协同数据分发技术　出处：《长安大学》2015年硕士论文　论文类型：学位论文

【摘要】：随着车联网技术的快速发展,基于车路系统的交通信息交互成为其中的关键问题。车路协同交通数据具有实时性强、突发性高等特点,因而研究车路协同数据实时交互方法显得尤为重要,特别是基于路侧设备的数据分发效率和机制直接影响到整个车路协同系统数据共享的实时性和可靠性。Wi-Fi Direct作为一种新兴的短程通信技术,正在得到广泛关注和推广。本文主要研究采用Wi-Fi Direct作为通信手段的车路协同交互系统中的数据分发问题,通过改进接入方法和分发算法,以满足车路协同的高效传输要求。首先,本文在深入分析车路协同系统应用特点、Wi-Fi Direct标准和接入机制、现有Wi-Fi Direct在车路协同接入性能上不足的基础上,提出了一种基于过滤信息的Wi-Fi Direct快速接入方法,该方法通过在接入申请信息中附加过滤数据帧实现对接入请求的快速响应,有效的提高了车载设备接入路侧基站的速度。其次,本文研究了车路协同系统的数据传输机制和数据特点,阐述了现有数据分发算法FCFS算法、RM算法、EDF算法的原理和优缺点以及其在车路系统数据分发中的可行性。针对实时性强的EDF动态优先级算法提出了改进的可变周期EDF算法APEDF算法,并且结合车路协同数据分发需求提出了车路环境下的CR-APEDF数据分发算法。最后,本文设计并实现了一种Android平台上的车路协同数据分发软件,包含Wi-Fi Direct接入模块、socket通信模快、数据传输模块、算法实现模块。在真实车路协同场景下,利用该软件测试了快速接入方法性能和CR-APEDF数据分发算法性能。测试结果表明,基于过滤信息的Wi-Fi Direct快速接入方法在接入速度上平均提高了30%以上;CR-APEDF算法在任务错失率、平均延迟、处理机利用率各项指标上优于其他算法;包含CR-APEDF算法的车路数据分发系统在静态和动态环境下都具有较大的数据分发吞吐量,满足车路协同实时性要求。
[Abstract]:With the rapid development of vehicle networking technology, the traffic information interaction based on vehicle-road system becomes a key problem. The vehicle-road cooperative traffic data has the characteristics of real-time and sudden. Therefore, it is very important to study the real-time interaction method of vehicle-road collaborative data. In particular, the efficiency and mechanism of data distribution based on roadside devices directly affect the real-time and reliability of data sharing in the whole vehicle-road collaborative system. Wi-Fi. Direct is a new short-range communication technology. This paper mainly studies the data distribution problem in the vehicle-road collaborative interaction system which uses Wi-Fi Direct as the communication means, and improves the access method and distribution algorithm. In order to meet the efficient transmission requirements of vehicle-road coordination. Firstly, this paper deeply analyzes the application characteristics of vehicle-road coordination system, Wi-Fi Direct standard and access mechanism. Based on the deficiency of the performance of the existing Wi-Fi Direct, a fast Wi-Fi Direct access method based on filtering information is proposed. The method realizes the fast response to the access request by adding the filtered data frame to the access request information, and effectively improves the speed of the vehicle equipment accessing the base station on the road side. Secondly. In this paper, the data transmission mechanism and data characteristics of the vehicle-road cooperative system are studied, and the existing data distribution algorithm (FCFS) and the RM algorithm are described. The principle, advantages and disadvantages of EDF algorithm and its feasibility in data distribution of vehicular system are discussed. An improved APEDF algorithm of variable period EDF algorithm is proposed for the real-time dynamic priority algorithm of EDF. In addition, the CR-APEDF data distribution algorithm in the vehicle-road environment is proposed according to the requirements of vehicle-road collaborative data distribution. Finally. This paper designs and implements a kind of vehicle-road cooperative data distribution software based on Android platform, which includes Wi-Fi Direct access module, socket communication module and data transmission module. The performance of fast access method and CR-APEDF data distribution algorithm are tested by using this software in the real vehicle-road collaborative scene. The test results show that. The Wi-Fi Direct fast access method based on filtering information improves the access speed by more than 30% on average. The CR-APEDF algorithm is superior to other algorithms in task miss rate, average delay and processor utilization ratio. The vehicle-road data distribution system including CR-APEDF algorithm has large data distribution throughput in both static and dynamic environment, which meets the real-time requirements of vehicle-road coordination.
【学位授予单位】：长安大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U495

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