Solutions for urban traffic issues by ITS technologies

In recent years, traffic congestion, traffic accidents, and deterioration of the environment because of growing population, increasing urbanization, and increasing car ownership have become serious problems in the Asia-Pacific regions. Intelligent transport systems (ITS) are systems that try to solve various road traffic issues using information communication technologies. Several countries are endeavoring to solve such traffic issues by deploying an ITS and achieving positive results. However, there are some problems in advancing ITS deployment in these countries, such as lack of technical know-how, a lack of coordination among systems, lack of a master plan, and financial constraints. In order to introduce ITSs, it is important to select suitable technologies and applications appropriate for each country. An appropriate plan and evaluation of the ITS project are also important for the introduction of ITS.In this paper, we propose methods for the utilization and introduction of ITS technologies to solve urban traffic issues in various countries, based on the lessons learned from the deployment of an ITS in Japan.     

云计算在智能交通中的应用

随着汽车数量的迅速增长,交通拥堵日益严重。交通参与者的交通行为变得繁杂多变,交通安全问题突出,交通流预测的准确度下降。为了给用户提供时时高效的交通信息,同时为交通管理部门提供有效的交通管制措施,必须完善智能交通系统的信息采集、处理、分析、存储和发布等功能。云计算具有分布式存储、超强计算能力、信息融合共享等优点,利用云计算的这些优点,构建智能交通系统云平台,实现交通信息从采集到发布全过程的优化,最显著的是提高了交通信息的时效性和准确性。云计算已经在基于GPS的浮动车技术、短时交通流预测、最优路径诱导和交通信号控制等智能交通的各个领域得到应用,并且对综合交通的发展起到了积极的推动作用。     

公路列车的体系框架与关键技术

环保、安全是交通运输领域备受关注的两大重要问题,智能交通系统(ITS)是解决这两大问题的一种有效方法。公路列车(Road Train)系统作为车用自组织网络(VANETs)在ITS领域的一个特殊应用,通过车车协同,整个公路列车队中,除头车由驾驶员驾驶,其他车辆都受头车发送的控制数据控制其自动驾驶。该系统集成了微电子技术、网络通信技术、多传感器集成技术以及车辆自动控制技术,旨在提高交通运输的安全性以及减少其所带来的环境污染,同时增加驾驶舒适性,其核心思想是通过车车通信的方式实现车辆之间的列队协同列队行驶。首先介绍了公路列车系统的概念,分析了公路列车系统的优点,提出了公路列车系统的体系框架结构,深入讨论了公路列车系统中所包含的关键技术,最后对公路列车系统进行了总结。     

基于小波融合的车牌模糊图像复原算法

为了更有效的实现交通信息采集,提出了一种基于小波融合的车牌图像超分辨率方法.首先分析了低分辨率图像的降质原因,主要降质因素包括:图像的形变、模糊和欠采样,根据这些降质因素建立了降质模型,分析降质模型,得出本文方法的理论模型.然后针对交通图像的特点,对形变、模糊和欠采样3个问题进行探讨,得出主要参数的估计方法.并对小波融...     

山区道路弯道上车辆自动减速系统分析、建模与设计

受弯道离心力影响,在弯道处车辆易发生侧滑和侧翻,山区道路转弯车道为交通事故高发区.车辆自动减速系统运用ITS技术自动控制车辆,使其能以安全车速通过弯道,避免交通事故发生.阐述车辆在转弯道处的运行机理,并对其在直线路段和曲线路段的运行情况分别建立数学模型,且对模型进行解析,以展现车辆自动减速系统的控制过程.通过对数学模型...     

台湾地区高快速公路资讯可变标志最适显示运用之研析

先进交通管理系统（advancedtrafficmanagementsystems,ATMS）所蒐集之交通资讯及交通管理策略,需经由先进用路人资讯系统（advancedtravelerinformationsystems,ATIS）发布後方显现效用,其中资讯可变标志（changeablemessagesign,CMS）为驾驶者在旅途中最重要的讯息来源。CMS主要显示内容包括交通宣导讯息、即时路段旅行时间及透过事件反应计画自动显示之路况资讯等,本研究针对CMS显示幕显示字体大小、辉度、显示时间,以及显示内容研提建议。依前述原则执行後,台湾地区高速公路用路人对CMS资讯内容的满意度达86．8,〈（2010）。本研究并分析台湾地区CMS中英文双语化之可行性,受限於版面空间、反应时间、系统转换时间及无法自由选择语言之特性,无法同时显示中英文资讯,故建议以使用中文之用路人为主;惟国外旅客较多之路段,建议挑选部分CMS显示英文旅行讯息,其余路段则维持发布中文资讯。     

基于云计算和WSN的车联网体系架构及关键技术研究

提出的基于云计算和WSN的车联网体系将着力于车车协同、车路协同、以及路网协同,并分析了将云计算和WSN运用到车联网体系中所涉及的关键技术。     

Cooperative GNSS positioning aided by road-features measurements

Cooperation between road users through V2X communication is a way to improve GNSS localization accuracy. When vehicles localization systems involve standalone GNSS receivers, the resulting accuracy can be affected by satellite-specific errors of several meters. This paper studies how road-features like lane marking detected by on-board cameras can be exploited to reduce absolute position errors of cooperative vehicles sharing information in real-time in a network. The algorithms considered in this work are based on a error bounded set membership strategy. In every vehicle, a set membership algorithm computes the absolute position and an estimation of the satellite-specific errors by using raw GNSS pseudoranges, lane boundary measurements and a 2D georeferenced road map which provides absolute geometric constraints. As lane-boundary measurements provide essentially cross-track corrections in the position estimation process, cooperation enables the vehicles to improve their own estimates thanks to the different orientation of the roads. Set-membership methods are very efficient to solve this problem since they do not involve any independence hypothesis of the errors and so, the same information can be used several times in the computation. Such class of algorithm provides a novel approach to improve position accuracy for connected vehicles guaranteeing the integrity of the computed solution which is pivoting for automated automotive systems requiring guaranteed safety-critical solutions. Results from simulations and real experiments show that sharing position corrections reduces significantly satellite-specific GNSS errors effects in both cross-track and along-track components. Moreover, it is shown that lane-boundary measurements help reducing estimation errors for all the networked vehicles even those which are not equipped with an embedded perception system.     

智能交通虚拟共用信息平台研究

提出一种虚拟共用信息平台技术(VCIP)作为ITS子系统间信息共享和信息集成的基本框架,以高效率低成本地完成数据共享和数据交换。VCIP结合了集中控制和分布处理的优势,具有开放性,根据访问授权与数据类型控制服务水平,支持跨平台ITS异构数据的转换与集成。分析了VCIP对ITS集成的重要作用,提出了VCIP的体系结构、操作机制和实现技术,并通过一个基于VCIP的出行信息系统———VCIP TIS原型系统验证了VCIP的特性和功能。     

平面交叉路口信号灯自动配时方案的优化算法

章提出了一种平面交叉路口的通用模型及描述各种实际路口的方法，根据路口各车流向的期望车流量实时预测结果，实时给出最优配时方案的算法。最后总结了算法的优点。