车辆网络通信平台的Internet接入研究

本文介绍了一种车辆通信系统嵌入式终端通过CPRS无线网络接入方式.车辆移动自组织网络与Internet互联的网络结构,车辆移动自组织网络与Internet网络相互通信的基本原理,以及以PPP协议为基础接入Internet互联网的方法,并针对车辆通信嵌入式系统平台的特点给出了车辆通信系统通过GPRS模块无线接入Internet的一些系统关键技术和方法.     

导航和无线通讯车载防碰撞装置算法研究

针对高速公路和非高速公路车辆之间交通事故频发的状况,设计了一种基于GPS和无线通信的车载汽车防碰撞装置,该装置即具备GPS导航功能,又具有语音播报车辆相互之间的距离和方位的功能,文中介绍了该装置的整体电路结构和基本原理,重点研究了应用本车采集GPS经纬度弧度(σ1,φ1)的位置信息和接收其它车辆经纬度弧度(σ2,φ2)的位置信息,计算车辆之间的地球球心夹角,应用弧长计算公式计算两车之间距离,分析研究推导出两车相对方位的计算公式,也给出了确定处于静止状态车辆的判断方法;所研制的装置在公路上进行了车载行驶测试;在400米范围之内显示其它车辆的方位、行驶的方向、距离、语音和报警信息准确,测试结果达到了预期设计要求。     

Infrastructure Deployment in Vehicular Communication Networks Using a Parallel Multiobjective Evolutionary Algorithm

This article describes the application of a multiobjective evolutionary algorithm for locating roadside infrastructure for vehicular communication networks over realistic urban areas. A multiobjective formulation of the problem is introduced, considering quality‐of‐service and cost objectives. The experimental analysis is performed over a real map of Málaga, using real traffic information and antennas, and scenarios that model different combinations of traffic patterns and applications (text/audio/video) in the communications. The proposed multiobjective evolutionary algorithm computes accurate trade‐off solutions, significantly improving over state‐of‐the‐art algorithms previously applied to the problem.     

在车载通信系统电磁兼容分析软件中嵌入AutoCAD的技术研究

本文论述了将AutoCAD嵌入车载通信系统电磁兼容分析软件的基本技术和设计方法;结合开发实践,给出了在该软件中嵌入AutoCAD的几个关键编程技术。实践表明,这些技术和方法嵌入效果好,故具有较好的推广性。     

Vehicular mobile commerce

Growing interest in mobile commerce among users, service providers, content developers, businesses, and researchers has spawned many new applications ncluding location-based services, mobile financial services, multiparty interactive games, and mobile auctions. Most of these applications are designed to be accessible via personal digital assistants or cell phones, but handhelds have limited capabilities and are impractical or dangerous to use while driving. Increased computing and communications power, coupled with advances in wireless networking technology and the explosive growth in wireless local area network (WLAN) deployments, have the potential to enable new m-commerce applications for drivers or passengers in motor vehicles. These applications range from entertainment and business services to diagnostic and safety tools. However, for vehicular m-commerce to become a reality, researchers must address a number of technical challenges.     

车载数据交互系统

设计了一种车载数据交互系统,采用触控交互界曲实现了对车辆信息的实时显示以及对车辆节点的控制,并利用嵌入式数据库SQL实现了对重要车载数据的实时备份,通过ARM-Linux操作系统平台对系统加以实现,达到了设计目的.     

基于自组织网的分布式车辆定位终端的设计

通过对车辆自组织网络相关通信技术的研究,提出了一种分布式车辆定位终端的设计与实现方案,该定位终端基于ARM嵌入式设计,整合了802.11通信模块、GPS定位模块以及LCD图形显示模块,可实时获取车辆位置信息并定时广播给周围其他车.每辆车通过802.11通信模块接收其他车信息,在显示屏幕上显示出周围车辆的位置分布情况,并采用本文提出的基于邻居列表的广播消息按需转播算法决定对收到的其他车消息的转播.该终端经实际应用测试,可较好地实现所提出的功能,在安全驾驶方面具有较重要意义.     

车载数据压缩算法

提出了一种适用于车载数据存储的线性拟合算法,采用基于ARM-Linux操作系统的SQL数据库为平台,对提出的压缩算法加以实现.实验结果表明:针对大量的连续数据具有良好的压缩效果,压缩后数据量急剧减少,尤其足在数据波动和采样间隔时间较小的情况下,给出的方法可实现较高的压缩比.     

车载容迟网络中一种基于真实轨迹的车辆移动模型

车辆移动模型的选择会严重影响车载容迟网络中关键技术的仿真研究结果.现有车辆移动模型大多属于合成移动模型,不符合真实环境.基于车辆真实移动轨迹建立车辆移动模型,考虑了道路拓扑选择、车辆速度控制、车辆初始位置选择以及路口转向选择等因素.在此基础上,进一步分析了模型对实际车辆行为模拟的接近程度、车辆的分布特性,以及基于该模型的网络连接特性.结果表明,提出的模型能够真实地逼近现实环境中车辆的实际行为.     

Theory of Manual Vehicular Control

The analytical basis of manual vehicular control theory is a combination of feedback systems analysis and mathematical models for human operators engaged in control tasks. Simplified representations for the operator-system combination are provided by the ‘ crossover model’, which is described in detail. The system dynamics and average performance of the crossover model system are developed. With these as bases, case studies are presented to illustrate the types of result which can be obtained from application of the operator-vehicle control theory. Two aircraft control examples illustrate the use of the theory and its empirical correlates to estimate operator dynamic characteristics, system performance, pilot ratings, pilot commentary, design implications, and some experimental guidelines. A driver-automobile example is presented to illustrate the use of the theory in structuring the key guidance and control features of the driver's visual field. A comprehensive bibliography of operator—vehicle system analysis applications is also provided     

车载环境下的语音端点检测方法

通过对车辆内部噪音的统计分析,对于车辆在不同的速度下的情况,分别采用短时能量-过零率及小波分析降噪的方式进行端点检测,利用Matlab软件进行了仿真实现.仿真结果表明:此方法兼顾了处理效率和准确性,对于车载环境下语音的实时处理有重要意义.     

无人车载以太网技术研究

随着人工智能的高速发展,其相关技术已经运用到生产生活的很多领域,在无人平台上,人工智能已经不可或缺。无人车网络系统由于智能感知的并入,使得传统的总线通信技术难以满足发展要求。车载以太网的出现能为大量数据高集成的通信系统提供一种有效解决方案。无人车载网络系统采用时间触发以太网的架构来进行设计。首先考虑整个时间触发网络系统的通信节点,针对通信链路设计相应的通信板卡。在板卡方面,主要设计了TTE交换机、端节点子系统控制器,为了增加整个系统的可靠性,采用了三余度通信结构。根据控制器和交换机相应的功能进行软件开发,并通过系统测试验证,满足各个系统通信任务需求,验证了此无人车网络系统可行性和准确性。     

Guest Editorial on Vehicular Networking Protocols

Vehicular communications is receiving an increased interest by the research community both from industry and academia. These technologies known as Vehicular Ad hoc Networks (VANET) include vehicle-to-infrastructure (V2I), and vehicle-to-vehicle (V2V) communications and can be based on various communications technologies. This special issue on Vehicular Networking Protocols technologies highlights new trends on networking protocols and their issues, further focusing on the Medium Access Control (MAC) layer and Physical (PHY) layer challenges. It also underlines on algorithms and protocols for data aggregation and group-based networking in vehicular networks.     

车载自组织网络中的数据分发机制

车载自组织网络（vehicular ad-hoc network,简称VANET）作为一种新型的移动自组织网络,应用前景广阔.鉴于长距离数据分发机制是支撑VANET应用的一个不可或缺的机制,提出了一种VANET下路边单元（roadsideunit,简称RSU）辅助的数据分发机制Ara,并在不同的交通场景下对其性能进行了评估.实验结果表明,即使在有RSU出现故障的情况下,Ara也可以保证较高的数据到达率、较小的延迟和较低的消息开销.同时,通过建立分析模型对Ara的数据传递延迟进行了理论分析.该分析模型建立在车辆的微观流模型之上,可以推导出不同RSU 部署场景下的数据传递延迟.模拟实验结果验证了模型的正确性,因此该分析模型可以对Ara数据传递的性能进行预测.     

Multi-Speaker Dialogue for Vehicular Navigation and Assistance

Currently, most Spoken Dialogue Systems (SDS) deal only with the interaction between the system and one speaker. In some situations, interaction may occur among several speakers and the system. New functions and improvements need to be made in order to handle a multi-user situation. Studies of the human-computer interaction system that involve multiple users are in their initial stages, and any papers, lectures or studies on the subject are very limited. For these reasons we are motivated to conduct a further study on Multi-Speaker Dialogue Systems (MSDS). In this paper, the interactions between the multiple speakers and the system are classified into three types: independent, cooperative, and conflicting interactions. An algorithm for the multi-speaker dialogue management is proposed. The algorithm determines the interaction type, integrates conversation goals for multiple speakers and keeps the interaction going smoothly. The experiments were carried out in a practical system which can provide useful vehicular information to drivers and passengers. Experimental results show that the proposed algorithm can handle the interaction that occurs in a multi-speaker dialogue system properly. The task completion rate is 76%, and more than 61% of the testers are satisfied with the proposed MSDS system.     

Probabilistic Adaptive Anonymous Authentication in Vehicular Networks

Vehicular networks have attracted extensive attention in recent years for their promises in improving safety and enabling other value-added services. Most previous work focuses on designing the media access and physical layer protocols. Privacy issues in vehicular systems have not been well addressed. We argue that privacy is a user-specific concept,and a good privacy protection mechanism should allow users to select the levels of privacy they wish to have. To address this requirement,we propose an adaptive anonymous authentication mechanism that can trade off the anonymity level with computational and communication overheads(resource usage) . This mechanism,to our knowledge,is the first effiort on adaptive anonymous authentication. The resources used by our protocol are few. A high traffic volume of 2000 vehicles per hour consumes about 60kbps bandwidth,which is less than one percent of the bandwidth of DSRC(Dedicated Short Range Communications) . By using adaptive anonymity,the protocol response time can further be improved 2～4 times with less than 20% bandwidth overheads.     

车用自组网信息广播

车用自组网作为移动自组网在智能交通系统中的应用,有望为人们提供更安全、效率更高的旅行方式.广播协议为危险警告、协同驾驶、路况通报等交通信息的发布提供了有效途径.简要介绍了车用自组网的特点和应用分类.采用分析和比较方法,讨论各种信息广播协议的特点、性能差异和应用范围,并针对车用自组网的特点及应用需求指出未来信息广播模型的设计思想和突破方向.     

公交数据驱动的城市车联网转发机制

在城市车联网中,由于交通状况复杂多变和出行路线多样性等特点,网络拓扑动态变化,车辆之间通信链路不稳定,影响着车联网数据传输性能.作为城市中重要的公共交通设施,公交车具有固定的行驶路线和发车时间,且公交线路广泛覆盖城市街道.与私家车相比,公交车是更好的数据携带者和转发者,有助于实现更可靠的车车通信.为此,提出公交数据驱动的城市车联网转发机制,简称BUF,旨在通过分析公交线路数据,选择合适的公交车做为转发节点,提高城市车联网数据传输效率.首先构建公交站点拓扑图,以目标场景中所有公交站点为顶点,在公交线路连续通过的站点之间连边,依据2个站点之间的预期公交车数量和距离计算边权值,进而使用迪杰斯特拉算法计算由源站点到目的站点的最优传输路径.为保证数据沿最优路径传输,优先选择与最优路径的后续站点重合度大于零的邻居骨干公交做为转发节点,且重合度越大越优先转发;当不存在骨干公交时,选择后续将经过期望的下一站点的邻居公交为转发节点,称为候补公交.针对不存在骨干公交和候补公交的场景,利用私家车建立多跳链路来寻找合适的公交转发节点,从而加速数据转发.使用北京市真实路网和公交线路数据的实验结果表明：与其他方案相比,BUF机制实现了更高的数据传输率和更短的传输时延.     

SDN在车载网中的应用综述

随着车载应用、移动设备和物联网的快速发展,开发处理车载网大数据的高效架构已成为未来智慧城市关注的重要问题。然而,车载网复杂且不灵活的架构面临一系列挑战,如高移动性、间歇性连接、应用程序的异构性。在这种背景下,软件定义网络(Software Defined Network,SDN)可编程和灵活的网络架构,在有线网络管理和异构无线通信中受到学术界和工业界的广泛关注。在车载网中应用SDN可以提高灵活性、可靠性、可编程性和可扩展性,增强车载网提供应用和服务的能力,提高用户服务质量。文中首先描述了SDN的体系结构,然后从架构和数据传播角度出发概括了软件定义车载网络(Software Defined Vehicular Networks,SDVN)的研究进展,随后概述了结合移动边缘计算(Mobile Edge Computing,MEC)的SDVN研究现状,接着讨论了SDVN存在的问题和挑战,最后介绍了SDVN的应用前景。