刍议汽车节能方法的运用

本文主要论述了当今汽车的节能意义与节能的相关途径。其重点从改变发动机设计、汽车轻量化技术和汽车驾驶技术三个方面探讨了汽车节能的新途径。     

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。     

全铝车身领衔新能源客车“轻装上阵”

正随着我国新能源客车的深入发展,客车轻量化的需求正变得更加迫切。轻量化之所以成为推动客车行业发展的重要因素,与当今社会对节能环保的迫切需求密切关联。这其中,车身作为整车质量的重头,成为客车轻量化的突破口,以全铝车身为代表的新材料、新工艺的运用,则成为客车企业轻量化之路的首选。近日,厦门金龙旅行车有限公司(简称"金旅客车")与     

对环保经济型汽车发展趋势的探讨

随着科技的进步,汽车材料向轻量化方面发展,本文对铝合金、塑料、稀土元素、工程陶瓷在汽车中的应用进行了介绍,质轻、环保、节能、经济型的汽车是时代发展的必然趋势。     

李克强:汽车产品结构变革时代正在到来

<正>"在互联网对汽车行业冲击不断升级的当下,互联网对汽车的影响目前正发生在汽车的设计、制造、销售、使用等环节,也表现在电商、后服务市场和制造之上,但更为重要的变化则体现在汽车产品结构的变革。""智能制造对于汽车设计不仅仅简单是客户的定制化问题,其中很重要的是未来所设计的产品结构应该发生变化。"在移动互联、大数据、云计算的推动下,未来汽车的技术变革是什么?在清华大学汽车系主任李克强看来,常规汽车制造商的领导者们所提出的电动化、智能化、轻量化似     

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。     

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.     

汽车节能探讨

文章从电子技术应用、新结构、新材料、新能源、正确驾驶、妥善保养等方面,较为深入地探讨了汽车节能的措施。     

全新梅赛德斯-奔驰ACTROS亮相中国

享誉全球的世界头号商用汽车制造商戴姆勒·克莱斯勒参加了2003年9月23-26日在华中经济重镇武汉举行的第四届中国武汉国际商用、专用汽车展览会.其全新梅赛德斯奔驰Actros系列载重车首次亮相中国市场,包括Actros3340S牵引车和Actros4140B混凝土搅拌车,另外一款Axor1840LS牵引车也首次在武汉亮相.     

现场签198台!这家车企实力不容小觑

正9月28日,华菱星马汽车集团专用车系列产品推介会在随州举行。随州市汽车办主任李西平、华菱星马汽车集团董事长刘汉如及公司相关领导以及来自随州地区共680余位新老客户、专用车企业代表、专用车经销商齐聚一堂,共同品鉴华菱星马专用车带来的价值盛宴。全系列专用车新品集中亮相在有着"中国专用汽车之都"美誉的随州举行如此声势浩大的推介会,华菱星马做足了准备:不仅带来了泵车、搅拌车、散装车、随车起重运输车、牵引车、五轴专用车底盘、     

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.     

公路沥青复合料冷再生路面的结构设计分析研究

公路路面冷再生翻新技术充分利用旧路破拆材料,处理和避免了旧路破拆垃圾,也一定程度节省了新料的投入,符合节能环保公路建设理念。但旧料冷再生利用,必须以新路面基本技术性能得到充分保证为前提。本文基于JTGD50-2017规范,参考国内公路沥青路面的毁损病害多发状态与冷再生复合料的基本性能功效,对公路沥青复合料冷再生新路面开展结构设计分析研究,探讨了三种路面厚度设计方案,提出了一个新的沥青复合料冷再生新路面的结构设计方法。     

Exploring the relationship between vehicle safety and fuel efficiency in automotive design

Panel data analysis is used within a fixed effect model to examine the relationship between vehicle safety ratings and fuel efficiency of 45 new vehicle models sold in the US between 2002 and 2007. While conventional wisdom and most early literature suggest that lighter, more fuel efficient vehicles are less safe to their occupants, the tests show a positive relationship between vehicle safety ratings and fuel efficiencies not only within and across most size classes but also for vehicles produced by both the US and Asian automakers. We also explore the design initiatives by manufacturers to compensate for the reductions in weight/size of fuel-efficient vehicles.     

The split-demand one-commodity pickup-and-delivery travelling salesman problem

This paper introduces a new vehicle routing problem transferring one commodity between customers with a capacitated vehicle that can visit a customer more than once, although a maximum number of visits must be respected. It generalizes the capacitated vehicle routing problem with split demands and some other variants recently addressed in the literature. We model the problem with a single commodity flow formulation and design a branch-and-cut approach to solve it. We make use of Benders Decomposition to project out the flow variables from the formulation. Inequalities to strengthen the linear programming relaxation are also presented and separated within the approach. Extensive computational results illustrate the performance of the approach on benchmark instances from the literature.     

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。     

Theory of safety surrogates using vehicle trajectories in macroscopic and microscopic settings: Application to dynamic message signs controlled traffic at work zones

This paper presents a new mathematical framework for obtaining quantitative safety measure using macroscopic as well as microscopic traffic data. The safety surrogate obtained from the macroscopic data is in terms of analysis performed on vehicle trajectories obtained from the macroscopic data. This method of obtaining safety measure can be used for many different types of applications. The safety surrogate for the traffic dynamics are developed in terms of a new concept of Negative Speed Differentials (NSD) that involve a convolution of vehicle speed function obtained from vehicle trajectories and then performing the integration of the square of the output for its negative values. The framework is applicable to microscopic traffic dynamics as well where we can use car following models for microscopic dynamics or the LWR model for macroscopic dynamics. This paper then presents the use of this new safety surrogate on the development of a feedback control law for controlling traffic in work zones using Dynamic Message Signs. A hybrid dynamics model is used to represent the switching dynamics due to changing DMS messages. A feedback control design for choosing those messages is presented as well as a simple simulation example to show its application.     

The process of information propagation in a traffic stream with a general vehicle headway: A revisit

Effective inter-vehicle communication is fundamental to a decentralized traffic information system based on mobile ad hoc vehicle networks. Here we model the information propagation process through inter-vehicle communication when the vehicle spacing follows a general i.i.d. distribution. Equations for the expected value and variance of propagation distance are derived. In addition, we provide simple equations for the expected number of vehicles covered and the probability distribution of propagation distance. This research advances on an earlier study where the vehicle spacing is assumed to follow an exponential distribution. This paper generalizes the earlier results and potentially enables a design for robust information propagation by allowing for examination of the impact of different headway distributions. Within the new modeling framework, we also compute connectivity between two vehicles.     

A new scenario based approach for designing driver support systems applied to the design of a lane change support system

Designing a new driver support system that meets the expectations of drivers is a difficult and time-consuming process. Despite the availability of various types of design support, it has essentially remained a process in which designers are forced to make assumptions about what other people want. This paper presents a new approach for determining users’ preferences and finding the best compromise between those preferences when designing a new driver support system. Using scenarios, virtual reality simulation, and gaming principles, the new approach gives users a pro-active role in the design process. To evaluate the new approach, it was applied to the design of a lane change support system. This resulted in a hierarchy of information that is a detailed, consistent and reliable image of users’ preferences. By combining this hierarchy with a manufacturing and marketing constraint, the design specification of a lane change support system was deduced. One of the many findings was that a lane change support system should be modular and that modules for the left side should be different from modules for the right side of the vehicle. The paper concludes with reasoning why the new approach offers added value for the design of driver support systems.     

浅谈立交改扩建方案设计

受交通量的发展和路网新布局的形成等因素影响,已建的许多互通式立交面临改扩建。文章以重庆江津西彭互通式立交在原有A型单喇叭三路互通立交基础上改建成四路立交的工程为例,阐述了改扩建立交在选型和设计过程中的思路,总结了一些改扩建立交方案选择的原则,供同行参考。     

Vehicle mass as a determinant of fuel consumption and secondary safety performance

One interaction between environmental and safety goals in transport is found within the vehicle fleet where fuel economy and secondary safety performance of individual vehicles impose conflicting requirements on vehicle mass from an individual’s perspective. Fleet characteristics influence the relationship between the environmental and safety outcomes of the fleet; the topic of this paper. Cross-sectional analysis of mass within the British fleet is used to estimate the partial effects of mass on the fuel consumption and secondary safety performance of vehicles. The results confirmed that fuel consumption increases as mass increases and is different for different combinations of fuel and transmission types. Additionally, increasing vehicle mass generally decreases the risk of injury to the driver of a given vehicle in the event of a crash. However, this relationship depends on the characteristics of the vehicle fleet, and in particular, is affected by changes in mass distribution within the fleet. We confirm that there is generally a trade-off in vehicle design between fuel economy and secondary safety performance imposed by mass. Cross-comparison of makes and models by model-specific effects reveal cases where this trade-off exists in other aspects of design. Although it is shown that mass imposes a trade-off in vehicle design between safety and fuel use, this does not necessarily mean that it imposes a trade-off between safety and environmental goals in the vehicle fleet as a whole because the secondary safety performance of a vehicle depends on both its own mass and the mass of the other vehicles with which it collides.