中国典型汽车道路谱研究的构建及应用

针对我国汽车道路谱缺失及滞后问题,分别从汽车道路谱的仪器集成、数据采集、数据库建立、数据分析和处理、应用软件的开发以及国家标准的建立等角度,概述了中国典型汽车道路谱研究的过程,并对中国典型汽车道路谱在汽车工程研究与开发中的应用进行了介绍,同时就中国典型汽车道路谱的研究前景进行了探讨和展望.     

典型道路谱的生成方法研究

代表地区路面不平度总体状况的道路谱数据,在汽车设计研发中起着重要作用,但目前缺少获取典型道路谱的方法。为了解决这一问题,本文提出了一种典型道路谱生成方法,该方法包含典型路段选取和测量、道路谱计算和滤波、典型道路谱提取三个主要步骤。以北京地区真实路面测量数据为例,进行典型道路谱生成,得到了能够表征某类路面的典型谱。该方法工程意义明确,效果明显,在汽车工程和道路工程领域有较大应用价值。     

典型路面的提取与合成方法研究

介绍了道路路面数据测量系统的构成和数据预处理方法。针对测量的道路路面数据,提取了可表征路面特点的特征参数,包括基本统计量、国际平整度指数和功率谱密度参数等。在此基础上,使用雷达图统计分析工具,提出了典型路段的提取与合成算法。并以北京地区真实的海量路面测量数据为例,进行了典型路面的提取与合成,得到了可反映和表征该地区路面特点的典型路面。最后总结了典型路面的提取与合成方法,展望了其应用前景。     

路面不平度研究综述

回顾了近年来汽车理论研究和道路谱分析领域中路面不平度的理论研究和发展现状。根据研究方向不同,分别从理论研究、试验分析和工程应用三个方面进行讨论。理论研究主要从路面不平度的定义出发,分析了其数学模型的研究进展;试验分析包括路面不平度测试测量技术的发展和不同类型试验分析与仿真计算的研究状况;路面不平度的工程应用主要针对其在汽车和道路各个方面的应用进行了讨论。文章综合论述了路面不平度的原理、特点及其在工程中的应用,最后还特别针对利用中国典型道路的路面不平度数据进行汽车设计与开发进行了阐述,并对路面不平度的研究前景进行了探讨和展望。     

道路路面测量数据的特征参数提取与统计分析

介绍道路路面数据测量系统的构成和数据预处理方法。针对测量的道路路面数据,阐述由路面数据提取可表征其特性的特征参数,包括基本统计量、国际平整度指数和功率谱密度参数等。在路面特征参数提取基础上,以北京地区真实海量路面测量数据为例,进行道路路面特征参数的统计分析,得到可反映、表征该地区路面特点的统计分析结果。总结道路路面特征参数提取与统计分析方法,展望其应用前景。     

频率自动测量系统的设计及实现

文章对频率自动测量系统组建作了简要介绍,探讨了运用SCPI在程序开发环境中快速、准确、方便地对频率信号进行自动测量和分析的特点,并对整个系统的不确定度进行了分析.同时介绍应用多线程技术在计量测试系统中实现环境监控及数据的实时采集及处理,以及它在提高系统测量准确性方面的意义.     

中国材料生命周期分析数据库开发及应用

生命周期分析作为广泛使用的环境管理工具,用于定量化评价产品系统整个生命周期内的潜在环境影响,其具体应用需要大量的不同层次、不同地区和不同技术水平的相关环境负荷数据和评价方法体系数据的支撑。在系列国家科技计划的支撑下,调研了典型材料生产的环境负荷数据,开展了中国材料环境数据库(SinoCenter)的研究,建立了中国材料生命周期分析数据库平台。数据库包含公用系统,典型材料(钢铁、建筑材料、有色金属、高分子材料、联接材料)等70多个数据集,近十万条环境负荷数据,并简要介绍了数据库的主要功能及数据库的技术和商业应用。     

基于功率谱密度的路面评价与特征参数提取

介绍了道路路面数据测量系统的构成和数据预处理方法。针对测量的海量道路路面数据,阐述了路面数据的功率谱密度分析与传统的功率谱分析的差异,解读了GB/T7031-2005中的倍频程滤波和路面分级方法,提出了基于拟合直线的斜率截距路面特征参数提取方法和基于功率谱密度曲线的路面分级百分比例特征参数提取方法。在介绍路面评价和特征参数提取方法的基础上,使用真实的路面测量数据作为例子,充分显示了这两种路面特征参数提取方法的效果。实例分析结果表明,使用这两种路面特征参数提取方法来评价和分析道路路面数据,计算过程快捷方便,处理效果简单明显,可在道路路面数据的特征参数提取及其它工程振动信号的统计分析中推广应用。     

汽车电器系统振动模拟试验寿命研究

为研究某汽车电器系统振动寿命,采用一种与用户相关的汽车试验场试验新规范开展试验场道路试验,利用加速度传感器法,采集试验场道路谱.对采集的道路谱作强化处理,根据处理后的数据进行汽车电器系统振动模拟试验,并运用图估计法分析模拟试验结果,建立此车型电器系统振动模拟试验寿命曲线图.结果表明,利用寿命曲线图计算汽车电器系统寿命里程,能大大缩短试验周期,具有一定的运用价值.     

基于LabVIEW的测量半自动化系统开发

设计并构建了一种基于LabVIEW的测量半自动化系统。该系统利用LabVIEW的VISA节点和报表生成工具包实现了数据的采集与Excel报表生成,并通过LabVIEW与数据库My SQL连接通信实现了数据存储,具有较高的应用价值。     

道路路面的剖面曲线测量研究与实践

回顾了近年来道路路面测量各种方法的研究现状,介绍了自主开发的高精度道路路面测量系统的测量原理和试验方法。在此基础上针对道路路面的真实剖面曲线测量方法进行了探讨和分析,并通过一些对比分析试验对该方法的测量误差进行了讨论,得到了较好的分析试验结果。最后针对道路路面的剖面曲线测量方法进行了总结,对该方法的应用范围和优缺点进行了评价。     

利用环境空气及路面温度对近距轮胎/路面噪音测量法(CPX)的修正(英文)

一般在公路上进行CPX轮胎/路面噪音测量时,环境温度对测量的影响往往是不易受控制的。研究人员们已针对此问题开发出一温度修正方法,透过不同的温度参数以补偿温度对量度得出的噪音水平之影响。本研究试图以一整天的CPX测量结果,以探索测试时使用环境气温和路面温度为本的修正及其可靠性,同时并得出两种路面上的温度修正值。     

基于VB与SQL的路谱管理系统设计与开发

获取实测振动PSD路谱后,因为路线多样、数据量庞大以及处理过程复杂,给实测振动PSD路谱工程化应用带来了极大的不便。为了有效地将实测数据运用于包装测试中,以Visual Basic 6.0为前台语言,SQLServer 2000为后台数据库,开发了路谱信息处理软件,实现了路谱数据从实际环境至实验室处理过程的所有步骤,并兼具了线路信息存储功能,同时分别建立了不同的数据库,满足数据存储与后期扩展、更新要求。     

Distribution and characteristics of road traffic crashes in the Chaoyang District of Beijing, China

In many developing urban settings, economic growth and motorization are coupled with increasing rates of road traffic injuries (RTIs). By highlighting typical sites and circumstances at/in which car crashes occur, more specific targets for prevention can be identified. The study is based on police data for a 1-year period and covers the Chaoyang District, the biggest district of Beijing City. Focus is placed on crash patterns and their distribution by types of road and areas. Both fatal and non-fatal crashes are considered (n=754). In the main, the crashes occurred in relatively favorable driving circumstances (e.g., sunny weather, flat and straight roads, asphalted roads, and good traffic signals and road markings). They were also quite evenly distributed over time of day, day of week and season. Five crash patterns were highlighted, of which three were strongly associated with specific areas and four with specific types of road. The study supports the idea that type of road and RTI severity or pattern are closely related. It contributes to the development of context-relevant prevention measures aimed at reducing road crashes and minimizing their consequences and also supports safe planning of the road traffic environment.     

Effects on road safety of new urban arterial roads

This paper presents an evaluation of the effects on road safety of new urban arterial roads in Oslo, Norway, and a synthesis of evidence from similar studies that have evaluated the safety effects of new urban arterial roads in other cities. A before-and-after study was made of four urban arterial road projects in Oslo. The study controlled for general accident trends in Oslo and for regression-to-the-mean. A statistically non-significant reduction of 9% in the number of injury accidents was found for all four projects combined. The effects on safety of new urban arterial roads were found to vary, depending on whether a new arterial road was built, or an existing arterial road upgraded by means of lane additions and reconstruction of junctions to interchanges. New arterial roads tend to induce more traffic, which tends to offset the benefits of a lower accident rate on the new roads. The results for other cities are very consistent with those for Oslo. For a total of seven cases in which new arterial roads were built, a statistically non-significant reduction of 1% in the number of injury accidents was found. Two cases that involved lane additions and converting at-grade junctions to interchanges resulted in a mean accident reduction of 51%, which was highly significant. On the average, the nine arterial road projects from which evidence was summarised resulted in a net induced traffic of 16%, and a net reduction in accident rate (accidents per million vehicle kilometres) of 18%. These effects almost cancel each other, leading to a very small net change in the expected number of accidents.     

Corridor-level signalized intersection safety analysis in Shanghai,China using Bayesian hierarchical models

Most traffic crashes in Chinese cities occur at signalized intersections. Research on the intersection safety problem in China is still in its early stage. The recent development of an advanced traffic information system in Shanghai enables in-depth intersection safety analyses using road design, traffic operation, and crash data. In Shanghai, the road network density is relatively high and the distance between signalized intersections is small, averaging about 200 m. Adjacent signalized intersections located along the same corridor share similar traffic flows, and signals are usually coordinated. Therefore, when studying intersection safety in Shanghai, it is essential to account for intersection correlations within corridors. In this study, data for 195 signalized intersections along 22 corridors in the urban areas of Shanghai were collected. Mean speeds and speed variances of corridors were acquired from taxis equipped with Global Positioning Systems (GPS). Bayesian hierarchical models were applied to identify crash risk factors at both the intersection and the corridor levels. Results showed that intersections along corridors with lower mean speeds were associated with fewer crashes than those with higher speeds, and those intersections along two-way roads, under elevated roads, and in close proximity to each other, tended to have higher crash frequencies.     

川渝地区可控震源道路激振效果分析

川渝地区地形地貌复杂,可控震源在其乡村道路激振时存在激发信号畸变较大及激发能量耗散较大等问题。为了解决该问题,建立了可控震源道路激振模型,构建了可控震源道路激振效果评价体系,开展了川渝地区可控震源乡村道路激振效果研究,分析了可控震源道路激振能量耗散。结果表明：构建的激振效果评价体系能够较为全面地对川渝地区可控震源道路激振效果进行评价;相比碎石土路,可控震源在无缺陷水泥道路激振时传地能量减弱48.31%,地表接触中心点振幅下降77.44%,互作用力振幅下降18.18%,信号畸变增大34.69%,激振效果较差;道路缺陷对激振效果具有明显的减弱影响,圆形孔洞道路缺陷对激振效果的影响尤为突出,其中传地能量减弱54.94%,地表接触中心点振幅下降5.57%,互作用力振幅下降21.16%,信号畸变增大36.17%;川渝地区可控震源道路激振时,平板的结构能量耗散较大,约占系统总耗散能量的90%。研究结果可以为川渝地区可控震源乡村道路激振效果的改善提供理论指导。