竞争中的车身结构及材料

一辆现代汽车约2/3质量是由钢构成的。今天,随着汽车安全性和舒适性要求的提高,减轻汽车质量是世界各汽车制造厂追求的一个首要目标。汽车的轻量化,一是设计轻量化结构,二是开发和使用新的结构材料。因此,传统的钢材料正受到轻金属尤其是铝及复合材料越来越大的挑战。     

与赛欧同一平台的赛宝多用途乘用车

上汽集团仪征汽车有限公司首辆赛宝多用途乘用车于2002年7月28日正式下线,使得三年来一直默默无闻的上汽集团仪征汽车有限公司终于放出光彩。上汽集团仪征汽车有限公司成立于1999年4月1日,是上汽集团和江苏仪征汽车公司联合重组后组建而     

汽车电子锁发展概述

汽车用锁是汽车车身的重要部件。虽然上个世纪末已经发明汽车，但直到本世纪末期，所有的汽车才安装上简单的机械锁。为了安全防盗且便于操纵，从70年代至今，以轿车为突破口，汽车用锁的发展趋势是由机械式向电气化至电子化演变。一、概念和特点汽车电子锁是采用电子电路控制，以电磁铁、微型电动机和销体或继电器作为执行机构的机电一体化保险装置。例如，汽车电子门销、汽车电子密码点火锁和汽车电脑转向锁等产品．都是电子镇应用于汽车的具体实例。使用汽车电子镇，驾驶员可以不用金属钥匙，舒适方便地自动控制汽车用锁，并且增强了汽车…     

沿长江七省市汽车工业现状及其特点

长江流域七省市是我国汽车工业最发达的地区之一，该地区汽车工业的状况和特点，基本能够反映出我国汽车工业的特点。目前，该地区汽车工业发展迅速，但产品结构和组织结构各有不同；汽车企业的经济规模和专业化水平有所提高，跨地区协作也正在发展，汽车制造企业和零部件企业的内制率逐年下降，零部件工业中“小巨人”企业已开始出现，该地区汽车企业积极推进改革，现代企业制度在逐渐形成，目前整车市场已呈卖方寡占竞争，但不太稳     

湖北汽车工业产品结构分析

围绕“效益结构”、“生产要素结构”两项指标对湖北汽车工业的汽车、改装汽车、摩托车、车用发动机及汽车摩托车零部件五项产品进行结构分析，为湖北汽车工业的结构调整提供服务。     

我国冷藏汽车的现状与发展趋势

冷藏汽车广义上泛指运输易腐货物的专用汽车，是公路冷藏运输的主要工具。我国专用汽车主管机构现又将其细分为保温汽车、冷藏汽车和保鲜汽车；只有隔热车体而无制冷机组的称为保温汽车；有隔热车体和制冷机组且厢内温度可调范围的下限低于0℃，用来运输冻结货物的称冷藏汽车，有隔热车和制冷机组（兼有加热功能 ），厢内温度可调范围均为0℃，用来运输新鲜货物的称保鲜汽车。     

汽车轮胎的发展

轮胎是汽车的重要部件之一，它直接与路面接触，和汽车悬架共同来缓和汽车行驶时所受到的冲击，保证汽车有良好的乘座舒适性和行驶平顺性；保证车轮和路面有良好的附着性，提高汽车的牵引性、制动性和通过性；承受着汽车的重量，轮胎在汽车上所起的重要作用越来越受到人们的重视。     

六年增长20倍我国汽车零部件出口结构分析

各大类产品出口额在零部件出口总额中的地位，是汽车零部件出口结构的一个重要体现。从2003年至今，这个结构的变化正好是加入WTO后我国汽车零部件出口产品结构变化的一个写照。     

汽车轻量化的现状及展望（续1）

减少汽车质量不仅是人类社会的需求，也是汽车使用者的需求。目前，世界上很多国家正在开展汽车轻量化的研究，并且有了富有成效的成果。为了达到减轻汽车质量的目的，最有效的途径是使用新材料、制造新技术和改进汽车结构。通过这些途径，汽车的安全性，舒适性，操纵性等都会得到提高。通常使用高强度钢板、铝合金、镁合金可以减轻汽车质量。新制造技术包括设计新结构、改善制造以及装配工艺。未来将不断研发新材料、新工艺，以满足汽车轻量化的更多需求。     

几种汽车零部件的新结构

在29届东京汽车博览会上,展出了几种汽车零部件的新品种,现简要介绍如下: 一、泄气后仍能继续行驶的轮胎和胎内压力报警系统日本布里奇斯通公司研制了一种新型汽车车轮,以提高轮胎泄气时继续行驶的性能,保证行车的安全。当汽车高速行驶时,如果轮胎突然破裂泄气,往往造成车辆失控。新型车轮是为了消除这种危险,以及减少换胎的不便和危险而设计的。采用这种车轮,即使轮胎泄气了,汽车仍能安全驶抵目的地。这种新型车轮由下述三个要素组     

Frequency Response Analysis of Canadian Logging Trucks

SUMMARY

This paper examines the frequency responses often logging truck configurations currently operating in the interior of British Columbia in Canada. The work is an extension of a previous study conducted at the National Research Council (NRC) in 1990. The previous study presented an extensive analysts of the directional responses and frequency responses of four Canadian log-hauling truck configurations; a tractor/pole trailer, a tractor/triaxle trailer, a tractor/quadaxle trailer (with a single load), and a tractor/single-axle-jeep/pole trailer. In the current study, the frequency responses of these four configurations are compared with those of six more log-hauling truck configurations; a tractor/ tandem-axle-jeep/pole trailer, a doglogger, a double doglogger, a tractor/quadaxle trailer (with a dual load), a tractor/jeep/triaxle trailer, and a tractor/jeep/quadaxle trailer. The current study makes use of three models developed by NRC in the previous study, and a new model developed at NRC in cooperation with the University of Victoria.

The frequency response method has been applied in this study to predict the lateral acceleration at the centre of gravity of each articulated vehicle unit, and the rearward amplification ratio. The logging truck simulation results have been compared with corresponding results, obtained using UMTRI's simplified models, for three conventional highway vehicles; a tractor/semitrailer, a B-train, and an A-train. The comparison provides a useful indication of the differences between the behaviours of logging trucks and conventional highway trucks in their shared environment.     

一种新型双动双腔真空增压器

EQ1060F轻型载货汽车的制动系统最初采用单腔制动总泵加单真空增压器及安全缸的半双管路结构。为了提高安全性，后采用双膜片真空助力器的双管路结构。为了适应使用要求，又改为两个真空增压器的方案，但仍存在结构复杂、接头环管多、易泄漏、自由行程过大，超载行驶时，感到制动力不足等问题。现采用一种新设计方案，以双腔制动总泵输出油压为控制源，用真空动力缸为增压机构，以双进、双出、双活塞的泵体为辅助缸，实现单真空增压器的双管路系统。     

考虑溶洞空间形态的路基岩溶顶板稳定性分析方法

岩溶路基随岩溶地区交通工程建设的快速发展而越来越普遍,如何评价岩溶路基稳定性成为岩溶区路基设计与施工的关键问题之一。针对目前路基岩溶顶板稳定性分析的不完善性,考虑溶洞形成过程中岩溶顶板所具有的空间形态特征,首先,将路基下伏岩溶顶板简化为固支梁、抛物线拱、圆拱与固支双向板等承载模型,以此进行路基岩溶顶板稳定性分析,并采用结构力学分析理论分别建立不同模型的路基岩溶顶板抗弯最小安全厚度计算方法;其次,通过典型案例的影响因素敏感性分析,揭示岩溶顶板最小安全厚度随溶洞顶板矢高、跨度、岩石抗拉强度与上覆荷载的变化规律,探讨路基岩溶顶板破坏模式的控制性因素及其影响规律,确定岩溶路基稳定性分析的基本原则;然后,基于岩溶地区地质勘察信息提出路基岩溶顶板稳定性分析过程,建立考虑溶洞空间形态特征的路基岩溶顶板稳定性分析方法;最后,通过工程实例计算分析验证所提方法确定的路基岩溶顶板稳定性评价结果的合理性与有效性。研究结果表明：岩溶顶板按何种模式破坏不仅与破坏形式有关,还与溶洞形态及其矢高密切相关,石灰岩抗拉强度同样影响较大,工程设计与稳定性评价时应基于勘测数据分析各种破坏模式,以便使设计或评价结果更接近实际情况。     

面向交通枢纽的车辆三维真实感实时仿真

为分析和解决城市交通拥挤问题并提高城市道路利用率提供可行的途径,提出了一种面向交通枢纽的车辆运行仿真方法,通过场景、道路与车辆的三维动态建模,实现交通枢纽交通状况的实时真实感仿真.首先,提出了基于道路关键点连接网络模型表示交通枢纽的通行道路.其次,基于粒子系统实现车辆的动态运行实时仿真,并采用基于空间剖分的车辆碰撞检测方法对车辆运动控制算法进行了优化.最终,通过对路段的动态观测和反馈机制实现车辆行驶路线的规划和调度.实验结果表明,本文提出的方法可以生动直观地呈现实际路面的交通状况,并且能以较为流畅的帧速率实现交通场景的动态仿真.     

Vehicle stability control using direct virtual sensors

The paper investigates the use of a direct virtual sensor (DVS) to replace a physical sensor in a vehicle stability control system. A yaw control system is considered and the proposed solution can be particularly useful when a fault of the yaw rate physical sensor occurs. A DVS is a stable linear filter derived directly from input–output data, collected in a preliminary experiment. In this work, it is shown that, by using data collected in a closed-loop fashion, better DVS accuracy can be obtained with a reduced number of measured variables. Moreover, the robust stability of the closed-loop system employing a DVS is studied. The effectiveness of the presented results is shown through numerical simulations of harsh manoeuvres, performed using a detailed model of a vehicle equipped with an active front steering device.     

基于频率法的索力测量系统

为了在工程现场快速方便地检测斜拉桥的拉索索力,依据随机振动法索力检测原理,开发了一种新型的索力测量系统。通过对随机振动法索力检测方法的概述,介绍了该系统的性能、硬件结构和软件模块,并重点阐述了通过数字滤波抑制快速傅里叶分析(FFT)的混频现象、自动扫描确定主振频率和提高索力计算精度的方法和措施。索力测量系统以AT89C55WD单片机(SCM)为平台,集成了电荷放大器、信号分析仪和计算器的相关功能。在工程现场,只需输入少量参数,拉索振动信号采集、信号的快速傅里叶分析和对应的索力计算即可在线自动完成。     

A vehicle type-based approach to model car following behaviors in simulation programs (case study: Car-motorcycle following behavior)

Traffic simulation models often neglect the important role of motorcycles and assume a flow of various combinations of cars. This paper addresses how much different would be the behavior of a car driver while following a motorcyclist compared to cases in which a car follows another car, along with a segment of an urban highway in the non-congested flow. Recognition of such a difference might help to develop existing simulation models and to improve the behavior of car drivers in such a way to lead to lower accidents with motorcycles. To reach the goal, a GHR (Gazis-Herman-Rothery) model for car following is applied and data have been collected by video cameras during 15?min time intervals in three different days. Analysis of 198 car-motorcycle and 374 car-car following observations has indicated that when a car driver follows a motorcycle, keeps a higher headway (about 10?m in the low speed) with a lower acceleration/deceleration in comparison with the situation in which car driver follow another one. It means that the behavior of the follower car driver would be more cautious compared to situations in which a car driver follows another one, especially in space headways <10?m. In addition to main findings of the paper for developing a more realistic simulation program, the paper also addresses that in cases when the required safe space between a car and a motorcycle would be endangered, a warning message could be generated for the car driver (by implementing an in-veh ITS technology) to warn driver about keeping a safe distance.     

2011上半年重卡市场分析及下半年展望

2011上半年,我国商用车产销同比分别下降6.07%和3.67%,除客车产销同比增长外,其余均低于上年同期,半挂牵引车降幅最为明显。我国汽车产销在持续了2年的高速增长后,由于国家宏观经济政策的调整、购置税优惠等有关利好政策的退出以及自身调整的影响,上半年增速大幅回落,由上年的高速增长转为平缓增长,且呈现逐月回落的走势。     

Slope Shift Strategy for Automatic Transmission Vehicles Based on the Road Gradient

Motivated by the development of high-precision digital maps for advanced driver assistance system (ADAS) in recent years, this study provides a new approach to solve the problems of the conventional automatic transmission vehicle travelling on sloping roads. Based on vehicle dynamics, shift problems on hilly roads are analyzed. A novel intelligent shift strategy is proposed, which consists of a dynamic shift schedule for the uphill, a safety shift schedule for the downhill, and a comprehensive economical shift schedule for the gentle slopes. A set of driver-in-loop co-simulation tests was conducted in a driving simulator that is equipped with a MATLAB/Simulink dynamics simulation platform. The test results verified the effectiveness of the new intelligent shift strategy. With the road information provided by a high-precision digital map, busy shifting can be eliminated, and improved dynamic performance can be achieved for a vehicle travelling on the uphill roads; undesired upshift can be prevented, and engine traction resistance can be used to relieve the load of braking system when a vehicle travelling on the downhill roads; also, fuel consumption can be reduced for a vehicle travelling on a gently sloped road. Consequently, this novel intelligent shift strategy offers a reliable and effective solution for improving a vehicle’s driving performance on a hilly road.     

基于ADVISOR的4轴全轮驱动车辆驱动系统仿真模块的开发

在研究4轴全轮驱动车辆的动力学特征基础上,对ADVISOR车辆仿真软件系统进行了二次开发,建立了该仿真系统不具备的某4轴全驱特定车型的动力系统仿真模型,并针对几种有代表性的循环行驶工况,利用该模型进行了整车性能的仿真和分析。