国内专用汽车发展现状浅析

文章阐述了我国专用汽车的发展概况,从专用汽车技术发展现状出发,分析了我国专用汽车发展中存在的问题以及发展趋势,并提出了相关建议.     

重卡轻量化，逐步突围

中国重卡企业正在尝试通过整车匹配和新材料应用,试图在轻量化技术上走得更远。如空气悬挂、铝合金、真空胎的使用等等,但核心技术的缺失让中国重卡轻量化之路步履维艰,甚至被质疑为“妖孽”。此外,中国运输市场的现状和用户的承受能力。却也实实在在限制了企业将研发成果转换成实际技术应用的脚步。     

东风随州专用汽车专攻天下

随州这座出土编钟的文化古城,以曾侯乙墓遗址出土的“鹿鹤”青铜器为市标,如今这座城市已成为国内“专用汽车之都”。东风随州专用汽车有限公司（下文简称“东风随专”）即坐落在这里。     

王立耀：轻量化发展需要“拿来主义”——商用汽车轻量化技术专家王立耀解读轻量化技术

汽车数量不断创新高,对全球环境构成越来越严重的挑战,新能源、轻量化等被提上日程,而轻量化被认为是更现实、更有效的节能减排举措。王立耀是国内最早研究商用汽车轻量化领域的权威专家。为解读轻量化技术在商用车方面的应用,本期独家策划采访了中国汽车工程学会常务理事王立耀先生,聆听专家是如何深度解读商用车轻量化技术的。     

品质江淮轻量化新体验

以“品质江淮新体验,牵财引富格尔发”为主题的江淮重卡轻量化牵引车上市品鉴会正如火如茶地展开,8月份相继在郑州、阜阳、青岛、上海等地上市,受到当地用户和经销商的热烈欢迎。     

轻量化，需要你的支持

雄关漫道真如铁,而今迈步从头越。关于商用车轻量化的专题报道,似乎用这句话来结束最为恰当。从2009年的年初开始,我刊就针对新能源汽车进行了多次报道,越深入越发现问题实在太多,电池问题、充电问题、     

轻量化星凯马顺势起航

随着国内超载限载以及计重收费法规的全面推广,为了留住用户或是吸引新客户,行业内重卡纷纷开始“减肥”,掀起新一轮重卡市场争夺战。代表华菱高端重卡的星凯马轻量化工作近年取得了长足的进步,在2月2日华菱公司营销大会上,董事长刘汉如表示,今年要加大力度推出为用户打造的全新的星凯马轻量化产品。     

轻量化：拨开迷雾——轻量化：不降低车辆性能的同时更省油

随着全球汽车数量的不断增加,10亿辆的庞大数字已经对地球能源和环境形成了巨大挑战,节能减排——成为全球汽车企业的集体课题。     

轻量化：江淮客车底盘的高效新体验

燃油价格的居高不下,以及节能减排的环保需要,在轻卡、重卡、客车等各个商用车领域刮起了一场“轻量化”节能风暴。     

轻量化成就“华菱之星”

面对2011年不利的市场环境,华菱公司通过推出细分市场产品积极应对,取得了良好的销量成绩,各月销量同比保持正向增长,其中轻量化车型——华菱之星功不可没。轻量化是重卡发展趋势之一,轻量化车型的开发是个系统工程,华菱之星重卡从开发调研到试制成功,到品质试验及多次改进再开发再到最后定型,花费近两年多的时间,确保交到用户手中的产品沿袭华菱产品一贯高品质的美誉,     

皮卡式清障车总体设计及市场应用

通过对高速针对常规清障车由于超高、转弯空间受限无法进入地下车库进行施救的难题,文章提出了专用皮卡式清障车的总体功能要求,探讨了总体布置、底盘选型与改造、专用装置结构设计等关键技术,研发并制造了皮卡式清障车样机,并进行了相应功能验证。在此基础上,深入剖析了皮卡式清障车在市场应用中所遇到的问题,并提倡将"主动救援新模式"常态化。     

浅谈氢燃料电池电动汽车布置设计

本文结合作者实际工作经验,介绍了某氢燃料电池电动汽车的电堆及其附件系统的布置设计,包括空气供应系统、氢气供应系统和电堆热管理系统,积累经验,供后来者参考。     

The design of electric vehicle charging network

The promotion of Electric Vehicles (EVs) has become a key measure of the governments in their attempt to reduce greenhouse gas emissions. However, range anxiety is a big barrier for drivers to choose EVs over traditional vehicles. Installing more charging stations in appropriate locations can relieve EV drivers’ range anxiety. To determine the locations of public charging stations, we propose two optimization models for two different charging modes - fast and slow charging, which aim at minimizing the total cost while satisfying certain coverage goal. Instead of using discrete points, we use geometric objects to represent charging demands. Importantly, to resolve the partial coverage problem (PCP) for networks, we extend the polygon overlay method to split the demands on the road network. After applying the models to Greater Toronto and Hamilton Area (GTHA) and to Downtown Toronto, we show that the proposed models are practical and effective in determining the locations of charging stations. Moreover, they can eliminate PCP and provide much more accurate results than the complementary partial coverage method (CP).     

An analysis of the effects of French vehicle inspection program and grant for scrappage on household vehicle transaction

The French government has implemented a periodical vehicle inspection program, which aims at maintaining proper functioning of the vehicle and ensuring the emissions control systems installed on the vehicle work properly. Also, an incentive program for scrapping old vehicles was introduced in 1994 through 1996 to promote the replacement of those vehicles with higher emissions by newer vehicles with lower emissions. A hazard-based duration model of household vehicle transaction behavior has been developed in this study to examine the effects of the inspection program and the grant for scrappage on vehicle transaction timing. The model is developed as a competing risks model assuming the following three types of competing risks: replacing one of the vehicles in the household fleet, disposing of one vehicle in the fleet, and acquiring one vehicle to add to the fleet. The empirical analysis is carried out using the panel data of French households' vehicle ownership from 1984 to 1998, obtained by the panel survey called Parc-Auto, which has been conducted by a French marketing firm, SOFRES, since 1976. The long panel observation period facilitates the introduction of macro-economic indicators into the model, enabling the analysis to distinguish the effects of policy measures from macro-economic factors. The empirical results indicate that the expected vehicle holding duration becomes 1.3 years longer under the inspection program than before the program commenced, given that the vehicle is replaced by another vehicle at the end of the holding duration; and that the conditional probability of replacing a vehicle aged 10 years and over becomes 1.2 times higher, and the average holding duration becomes shorter by 3.3 years, when the grant for scrappage is available.     

A structural analysis of vehicle design responses to Corporate Average Fuel Economy policy

The US Corporate Average Fuel Economy (CAFE) regulations are intended to influence automaker vehicle design and pricing choices. CAFE policy has been in effect for the past three decades, and new legislation has raised standards significantly. We present a structural analysis of automaker responses to generic CAFE policies. We depart from prior CAFE analyses by focusing on vehicle design responses in long-run oligopolistic equilibrium, and we view vehicles as differentiated products, taking demand as a general function of price and product attributes. We find that under general cost, demand, and performance functions, single-product profit maximizing firm responses to CAFE standards follow a distinct pattern: firms ignore CAFE when the standard is low, treat CAFE as a vehicle design constraint for moderate standards, and violate CAFE when the standard is high. Further, the point and extent of first violation depends upon the penalty for violation, and the corresponding vehicle design is independent of further standard increases. Thus, increasing CAFE standards will eventually have no further impact on vehicle design if the penalty for violation is also not increased. We implement a case study by incorporating vehicle physics simulation, vehicle manufacturing and technology cost models, and a mixed logit demand model to examine equilibrium powertrain design and price decisions for a fixed vehicle body. Results indicate that equilibrium vehicle design is not bound by current CAFE standards, and vehicle design decisions are directly determined by market competition and consumer preferences. We find that with increased fuel economy standards, a higher violation penalty than the current stagnant penalty is needed to cause firms to increase their design fuel economy at equilibrium. However, the maximum attainable improvement can be modest even if the penalty is doubled. We also find that firms’ design responses are more sensitive to variation in fuel prices than to CAFE standards, within the examined ranges.     

Using connected vehicle technology to improve the efficiency of intersections

Information from connected vehicles, such as the position and speed of individual vehicles, can be used to optimize traffic operations at an intersection. This paper proposes such an algorithm for two one-way-streets assuming that only a certain percentage of cars are equipped with this technology. The algorithm enumerates different sequences of cars discharging from the intersection to minimize the objective function. Benefits of platooning (multiple cars consecutively discharging from a queue) and signal flexibility (adaptability to demand) are also considered. The goal is to gain insights about the value (in terms of delay savings) of using connected vehicle technology for intersection control.Simulations are conducted for different total demand values and demand ratios to understand the effects of changing the minimum green time at the signal and the penetration rate of connected cars. Using autonomous vehicle control systems, the signal could rapidly change the direction of priority without relying on the reaction of drivers. However, without this technology a minimum green time is necessary. The results of the simulations show that a minimum green time increases the delay only for the low and balanced demand scenarios. Therefore, the value of using cars with autonomous vehicle control can only be seen at intersections with this kind of demand patterns, and could result in up to 7% decrease in delay. On the other hand, using information from connected vehicles to better adapt the traffic signal has proven to be indeed very valuable. Increases in the penetration rate from 0% up to 60% can significantly reduce the average delay (in low demand scenarios a decrease in delay of up to 60% can be observed). That being said, after a penetration rate of 60%, while the delays continue to decrease, the rate of reduction decreases and the marginal value of information from communication technologies diminishes. Overall, it is observed that connected vehicle technology could significantly improve the operation of traffic at signalized intersections, at least under the proposed algorithm.     

总承包模式下的柬埔寨某国道改建项目设计方案优化

总承包是目前国际工程项目常用的一种建设模式。通过对国内外工程建设程序和承包建设模式特征的分析,结合柬埔寨某国道改建项目的实践总结,探讨了在国际项目中的总承包模式下,如何在实施阶段通过设计方案的优化来降低工程数量、施工难度及对环境的影响。     

Impact of vehicle usage on consumer choice of hybrid electric vehicles

We analyze the vehicle usage and consumer profile attributes extracted from both National Household Travel Survey and Vehicle Quality Survey data to understand the impact of vehicle usage upon consumers’ choices of hybrid electric vehicles in the US. In addition, the key characteristics of hybrid vehicle drivers are identified to determine the market segmentations of hybrid electric vehicles and the critical attributes to include in the choice model. After a compatibility test of two datasets, a pooled choice model combining both data sources illustrates the significant influences of vehicle usage upon consumers’ choices of hybrid electric vehicles. Even though the data-bases have in the past been used independently to study travel behavior and vehicle quality ratings, here we use them together.     

智能车辆控制SIMULINK仿真中自定义模块的创建

介绍SIMULINK中用嵌入式MATLAB函数(EmbeddedMATLAB Function)创建自定义算法模块的方法,并利用嵌入式MATLAB函数的M文件编辑器,编写了实现智能车辆控制仿真过程中状态切换控制算法的M源文件,应用测试模型测试了其准确性。具体实例表明,SIMULINK中嵌入式MATLAB函数自定义算法模块可以大大简化复杂建模过程,减少工程人员的工作量,在此基础上实现动态仿真过程的可视化,扩展了SIIMULINK的应用领域。