车辆经济性提升方向研究

本文从整车整备质量、整车滑行阻力、变速箱控制策略、发动机怠速油耗等影响整车经济性因素出发,对某车型A与对标车型B经济性差异进行分析.通过计算机仿真和实车试验验证在保证动力性基本不损失的情况下分析不同因素对油耗的影响,明确不同影响因素对整车经济性的影响程度.为整车研发阶段提升整车经济性,降低整车油耗提供参考及方向.     

新安凯亮相北京道路运输车辆展

2014年5月14日,2014北京国际道路运输、城市公交车辆及零部件展览会（以下简称道路运输车辆展）在北京国家会议中心隆重召开。由中国交通部主办的这次盛会,从2009年至今已经成功举办5届,今年展会吸引了数百家整车厂家和零配件厂家,展会面积达到30000平米,规模创历年之最。     

RFID助力零部件全生命周期追溯

有些重型卡车车主将非本车的磨损零部件进行保内维修或更换,由于无法追溯磨损零件,但在合同期内,汽车制造企业仍须执行维修或更换,造成巨大损失。汽车制造需要众多零部件,对这些零部件的管理是一项浩大的工程。随着需求量的增大,传统的人工记录出现瓶颈—人工记录零部件库存、生产线状态,效率低下,影响到进出货速度、生产速度,且大量数据的转抄降     

基于冷却液温度的发动机性能优化研究

在台架上对不同冷却液温度下发动机性能测试的基础上,分析了温度对发动机基本性能影响。基于转速和负荷,给出最优目标温度Map图并进行整车油耗仿真计算。结果表明,冷却液温度对发动机低速工况下动力性和经济性有较大影响;与装配蜡式节温器的整车相比,整车采用优化后的水温Map将会使综合油耗降低1%左右。     

"零整"行动再出击谭旭光左右互搏

陕汽作为产业链终端的重卡制造企业,通过和康明斯发动机合作等动作整合零部件企业,与潍柴动力作为核心零部件企业,通过和曼集团、陕重汽、法士特等合作整合产业链资源,目的都是打造一个拥有整车及核心零部件的重型汽车集团。虽然两者目的相同,但一山不容两虎的古训会让这个"黄金产业链"走向何方?个中味道耐人琢磨。     

传统燃油车的电动化改制方案研究

文章以前置后驱的传统燃油车改制为前置前驱的纯电动汽车案例,展开整车设计分析,在维持原型车的外形、长宽高、轴距和轮距等基本参数的基础上,提出了整车布置结构变化的改制设计方案,设定了电动车整车主要性能指标。在电动化设计中取消了传统燃油动力总成及其附属的燃油、进排气等系统,依据整车性能目标要求,结合车辆空间及整车结构原理,对驱动电机动力总成、电池PACK、VCU、PDC三合一等高压系统零部件进行选型及布置设计。     

金旅:打造新能源和传统客车“多面手”

正3月30日,2017年(天津)国际客运交通装备与技术展览会在天津梅江展览中心隆举行,展会由中国道路运输协会城市客运分会、天津公交集团主办,以绿色出行、智慧交通、创新技术应用为主题,近百家整车制造以及高新技术创新型零部件企业参展,共同推动客运行业的稳步发展。作为客车行业2017上半年重大行业活动,金旅此次携三款最新研发升级车型集体亮相,其中一款为2016年上市的D8纯电大考斯特,另外两款首次亮相车型为汽油版考斯特高端商务     

车身物理实验对车身尺寸控制的重要性

随着汽车产业的发展竞争也越来越激烈,汽车产品需要不断的提高其外观质量要求,以吸引消费者的第一感觉,且良好的外观尺寸保证有助于提升整车的表面完整性,降低汽车的风阻和风噪,有利于整车油耗降低和舒适性提升。然而白车身在油漆过程以及完成后装配总装零件,总装零件的重量以及压缩力(气弹簧、密封条)会对开启件与白车身的相对位置发生偏移,而且现在汽车内饰为了增加隔音效果,重量也在不断增加;同时为提高开启件的声音品质,密封条的断面设计也越来越复杂,势必对开启件的尺寸控制增加难度。本文通过物理实验的方法对两类典型的开启件变形进行分析和研究。     

基于TruckSim的重型清障车操纵稳定性分析

国内清障车主要使用的是载货汽车的二类汽车底盘,这种底盘在整车的结构布置和承力方式上有许多不满足清障车专用作业装置的布置需求。本文以重型清障车的操纵稳定性为研究目标,基于TruckSim软件建立某款重型清障车工程样车的整车模型,参照《GB/T 6323-2014汽车操纵稳定性试验方法》对汽车进行稳定性仿真试验,选取不同质心高度和质心纵向位移进行开环评价和闭环评价对比分析。结果表明在原设计参数的基础上降低车辆的质心高度和前移质心纵向位移,对车辆的操纵稳定性具有一定的提高。     

整车参数对混合动力汽车NEDC工况油耗的影响

混合动力整车油耗不仅仅取决于混合动力系统的优劣,与整车参数也有很大的关系,但混合动力汽车与传统汽车相比,整车参数对油耗的影响是有一定差别的,本文研究了一些主要的整车参数对混合动力汽车的油耗影响。基于功率分流式混合动力车辆的Amesim仿真模型,选取整车质量、轮胎滚动半径、滑行阻力曲线三个因素并利用正交表的方法分析其对油耗的影响,从而指导利用该模型进行功率分流式混合动力车辆的油耗分析和优化。研究表明,混合动力汽车由于制动能量回收的影响,整备质量对油耗的影响小于传统汽车;由于功率分流的能量控制策略,轮胎滚动半径对油耗的影响很小;滑行阻力对油耗的影响和传统汽车接近。     

Exploring public bicycle network structure based on complex network theory and shortest path analysis: the public bicycle system in Yixing,China

A well-functioning public bicycle system relates not only to its mode of operation, vehicle allocation, rental station layout and vehicle leasing configuration, but also the bicycle network structure and its formation. However, the latter aspects have been widely overlooked in China. Here, we help to further attract more researchers to conduct relevant studies and make suggestions for the development of public bicycle transport in many small and medium-sized cities across the world. We demonstrate how to explore the public bicycle network structure of a county-level Chinese city – Yixing – known for its clay ware and tourism. We show that complex network theory and shortest path analysis technology are useful in characterizing the public bicycle network structure, in aspects such as network topology, the spatial distribution of sub-networks and traffic flows. Finally, the paper proposes relevant urban planning strategies.     

Vehicle energy efficiency evaluation from well-to-wheel lifecycle perspective

Given a fundamental role of automobiles in human society, evaluation of vehicle energy efficiency is of utmost importance. Various reports have been published hitherto concerning well-to-wheel (WTW) fuel consumption at the vehicle operation phase. On the other hand, WTW energy consumption at other lifecycle phases has been scarcely integrated in the assessment of vehicle energy efficiency. Particularly, WTW energy consumption for material structure is significantly associated with fuel economy. As such, this paper firstly analyzes the lifecycle WTW vehicle energy efficiency from the perspective of both material structures at the manufacture phase and fuel consumption at the operation phase for conventional vehicle (CV), electric vehicle (EV), hybrid vehicle (HV) and fuel cell vehicle (FCV). Then, an expected transition of vehicle weight and energy consumption arising from material structural shift through the replacement of steel with aluminum is evaluated. Finally, the overall vehicle energy efficiency in Japan in 2020–2050 is projected. It is discovered that the inclusion of energy consumption for material structure has a significant impact on the determination of the vehicle energy efficiency, particularly for new generation vehicles. WTW analysis at the multiple lifecycle phases may be of use in establishing more comprehensive principles of vehicle energy efficiency.     

Effectiveness and costs of odor repellents in wildlife–vehicle collisions: A case study in Central Bohemia,Czech Republic

This article summarizes the results of the field tests, when the efficiency and financial costs of the chosen odor repellents to reduce mortality of animals on selected roads and railways in the Czech Republic during the years 2011–2013 were evaluated. The main objective was to determine whether by using repellents it is possible to reduce the number of animals killed and evaluate the return of financial costs that are associated with the application of the repellents. Our results showed that the odor repellents are an effective tool to reduce wildlife–vehicle collision (WVC), and thanks to their application it was possible to reduce the cost of damage to property and reduce the number of killed animals by comparing the years 2011 (without measure) and 2013 (2 years of repellent application) by 37% of the initial loss.     

Vehicle detection grammars with partial occlusion handling for traffic surveillance

Traffic surveillance is an important topic in intelligent transportation systems (ITS). Robust vehicle detection is one challenging problem for complex traffic surveillance. In this paper, we propose an efficient vehicle detection method by designing vehicle detection grammars and handling partial occlusion. The grammar model is implemented by novel detection grammars, including structure, deformation and pairwise SVM grammars. First, the vehicle is divided into its constitute parts, called semantic parts, which can represent the vehicle effectively. To increase the robustness of part detection, the semantic parts are represented by their detection score maps. The semantic parts are further divided into sub-parts automatically. The two-layer division of the vehicle is modeled into a grammar model. Then, the grammar model is trained by a designed training procedure to get ideal grammar parameters, including appearance models and grammar productions. After that, vehicle detection is executed by a designed detection procedure with respect to the grammar model. Finally, the issue of vehicle occlusion is handled by designing and training specific grammars. The strategy adopted by our method is first to divide the vehicle into the semantic parts and sub-parts, then to train the grammar productions for semantic parts and sub-parts by introducing novel pairwise SVM grammars and finally to detect the vehicle by applying the trained grammars. Experiments in practical urban scenarios are carried out for complex traffic surveillance. It can be shown that our method adapts to partial occlusion and various challenging cases.     

Feebates, footprints and highway safety

This paper presents an analysis of a market-based policy aimed at encouraging manufacturers to develop more fuel efficient vehicles without affecting the car buyer’s choice of vehicle size. A vehicle’s size is measured by its “footprint”, the product of track width and wheelbase. Traditional market-based policies to promote higher fuel economy, such as higher gasoline taxes or gas guzzler taxes, also induce motorists to purchase smaller vehicles. Whether or not such policies affect overall road safety remains controversial, however. Feebates, a continuous schedule of new vehicle taxes and rebates as a function of vehicle fuel consumption, can also be made a function of vehicle size, thus removing the incentive to buy a smaller vehicle. A feebate system based on a vehicle’s footprint creates the same incentive to adopt technology to improve fuel economy as simple feebate systems while removing any incentive for manufacturers or consumers to downsize vehicles.     

Accident severity analysis using ordered probit model

To reduce injuries in road crashes, better understanding is needed between the relationship of injury severity and risk factors. This study seeks to identify the contributing factors affecting crash severity with broad considerations of driver characteristics, roadway features, vehicle types, pedestrian characteristics and crash characteristics using an ordered probit model. It also explores how the interaction of these factors will affect accident severity risk. Three types of accidents were investigated: two-vehicle crashes, single vehicle crashes and pedestrian accidents. The reported crash data in Singapore from 1992 to 2001 were used to illustrate the process of parameter estimation. Several factors such as vehicle type, road type, collision type, location type, pedestrian age, time of day of accident occurrence were found to be significantly associated with injury severity. It was also found that injury severity decreases over time for the three types of accident investigated.     

Deciphering interactions between white-tailed deer and approaching vehicles

Deer-vehicle collisions are a major transportation hazard, but factors affecting deer escape decision-making in response to vehicle approach remain poorly characterized. We made opportunistic observations of deer response to vehicle approach during daylight hours on a restricted-access facility in Ohio, USA (vehicle speeds were ≤64 km/h). We hypothesized that animal proximity to the road, group size, vehicle approach, and ambient conditions would affect perceived risk by white-tailed deer (Odocoileus virginianus) to vehicle approach, as measured by flight-initiation distance (FID). We constructed a priori models for FID, as well as road-crossing behavior. Deer responses were variable and did not demonstrate spatial or temporal margins of safety. Road-crossing behavior was slightly and positively influenced by group size during winter. Deer showed greater FIDs and likelihood of crossing when approached in the road; directionality of approach likely increased the perceived risk. These findings are consistent with antipredator theory relative to predator approach direction.     

关于车-路垂向耦合模型的分析

文章将车辆、道路作为整体系统的两个部分,把车辆简化为四自由度的1/2车辆模型,将道路离散为弹性多层体系的有限元模型,通过建立车辆道路耦合动力分析模型,推导出了系统的动力平衡方程组,并探讨了方程组的解耦方法,提出了反映车辆运行品质和道路设计参数的理论计算指标,为车路耦合动力分析的进一步研究提供了参考。     

An integrated model for discrete and continuous decisions with application to vehicle ownership,type and usage choices

This paper proposes an integrated econometric framework for discrete and continuous choice dimensions. The model system is applied to the problem of household vehicle ownership, type and usage. A multinomial probit is used to estimate household vehicle ownership, a multinomial logit is used to estimate the vehicle type (class and vintage) choices, and a regression is used to estimate the vehicle usage decisions. Correlation between the discrete (number of vehicles) and the continuous (total annual miles traveled) parts is captured with a full variance–covariance matrix of the unobserved factors. The model system is estimated using Simulated Log-Likelihood methods on data extracted from the 2009 US National Household Travel Survey and a secondary dataset on vehicle characteristics. Model estimates are applied to evaluate changes in vehicle holding and miles driven, in response to the evolution of social societies, living environment and transportation policies.     

临时关闭道路以疏导城市道路交通流的可行性分析

文章基于Braess悖论,以单位车辆的平均出行时间为最优目标,以网络道路系统为约束条件,从逆向思维角度建立了通过临时关闭道路引导交通流以缓解城市道路交通拥挤的Narsh均衡非线性规划模型,并以北京二环道路网络为研究对象进行了实例分析。结果表明,在城市道路网中,关闭部分路段并不能明显缓解交通拥堵现状,但可以在不影响路网整体通行时间的条件下改善路网局部拥堵状况。建议城市道路交通临时疏导方案应该根据路网交通流的分布特点和道路通过能力等因素进行制订。