基于线控转向的汽车转向系统技术研究

线控转向(Steering-By-Wire)是汽车转向系统发展中最新的技术.介绍了汽车转向系统的发展趋势和线控转向技术发展中应用的关键技术,总结了其性能特点以及现阶段开发应用中的主要问题,分析了汽车线控转向系统的结构及工作原理,指出了线控转向系统的优点和应用前景,展望了其研究发展趋势.     

汽车转向助力泵溢流阀流场分析与结构优化

借助流体分析软件Fluent构建了关于溢流阀的内流域模型,并基于该模型建立了有限元分析模型,通过设定相关的参量实施了多次迭代计算得到基本性能参数。借助分析结果改进了既有结构,并采用相同的方法对两种改进结构实施了性能分析,通过分析发现,在速度场及压力场等方面,优化后的结构有着显著改善。通过本文的研究,对溢流阀结构和性能进行了系统探索,获得了预期的研究成果。     

基于地面坐标系的二自由度模型汽车转向特性分析

以建立在地面静坐标系下的汽车二自由度模型为基础,以绝对运动的侧向位移y和横摆角度θ为分析变量来标征汽车侧向和横摆运动,分析了汽车转向的稳态和瞬态两种情况,给出了稳态线性情况下的不足转向梯度η,最后通过拉氏变换给出了y和θ的解析式,并结合实例进行了计算分析.     

汽车电动助力转向系统控制策略的研究

文章系统阐述了电动助力转向系统的控制策略和控制方法。通过比较电压控制方式和电流控制方式,得出电流控制方式明显优于电压控制方式的结论;并重点分析了在电流控制方式下的控制策略(包括助力控制、回正控制和阻尼控制),并在SIMULINK中进行了仿真。     

汽车整体式转向梯形机构仿真计算与优化

本文通过建立整体式转向梯形机构的简化的平面数学模型,确定了转向梯形的特性函数;通过推导外侧转向车轮的实际转角与转向梯形机构传动角的计算公式,建立了目标函数模型,确定了约束条件;通过对仿真结果进行分析,验证了优化设计结果的优点。     

汽车新节能技术的展望

文章介绍了目前国际上几种比较新颖的节能技术,诸如能量收集与储存新技术、汽主行驶中的能量回收再生技术,电容器和电池二次电池能量回收再生技术、飞轮电动汽车的能量回收与利用技术等等。     

浅谈汽车代用燃料技术

根据我国的自然条件和"富煤贫油"的能源资源条件,开发和发展汽油清洁代用燃料,可降低对石油燃料的依赖性,减轻对石油燃料需求的压力,有利于环境保护和降低成本,可获得巨大的社会效益和经济效益.     

中国汽车质量网典型投诉案例分析 福克斯转向机漏油

本阶段中国汽车质量网（www．12365auto．com）共收到消囊者针对汽车产品或者服务的质量投诉387宗,由于历经十一长假,环比减少了113例,共涉及车型150多赦。东风标致408依然名列榜首。其他进螃车型也大都是老问题。长安福特福克斯则因为转向机漏油问题频发引发了集体投诉而进入前十名。     

整体式转向梯形机构的优化设计

转向梯形机构是使汽车转向时实现内、外轮理想转角关系的核心部件。建立了整体式转向梯形机构的数学模型,介绍了基于MATLAB优化工具箱的整体式转向梯形机构的优化设计计算程序。利用该程序,用户可以交互式输入结构基本参数,即可得到优化计算结果,并自动绘制出实际输出角和输出角期望值随输入角的变化曲线,以便用户分析、比较和选择。为转向梯形设计提供了高效、精确的实用方法。     

高速公路软基水泥搅拌桩处理关键技术探讨

水泥搅拌桩作为一种较好的地基加固技术,在公路软土地基处理中应用广泛。文章系统地阐述了水泥搅拌桩的适用范围,设计前期准备工作、设计参数等水泥搅拌桩设计关键技术和施工成桩试验、施工参数设计等水泥搅拌桩施工关键技术,并介绍了水泥搅拌桩质量检测方法,为高速公路软土地基水泥搅拌桩设计和施工提供参考。     

浅析高速公路供配电节能技术

供配电系统是高速公路中的重要组成部分,近年来随着我国高速公路建设的迅速发展,供配电系统的电力支出费用越来越大。高速公路的供配电节能技术既要保证公路电力设施的安全性又要保证其节能性,文章针对我国高速公路供配电系统的运营现状,分析供配电节能技术,希望可以有效促进我国高速公路经济效益的增长。     

公路限速标志设置的位置研究

公路限速标志是现代交通管理中最普遍的控制车速的方式,也是保障道路交通安全的基础设施。文章介绍了限速标志设置的基本要求,分析了我国限速标志设置存在的问题,并从限速标志设置的地点、路段、位置点、距离和限速值等方面论证限速标志设置的位置,为科学设置公路限速标志提供参考。     

高速车辆检测系统中数据匹配算法研究

文章在《高速公路超限运输网络管理系统》中车牌与称重数据的匹配算法基础上,阐述了算法的理论基础,给出了基于C＋＋语言的主要实现代码,为解决高速车辆检测系统中不同检测设备的数据匹配问题提供了一种可行的方法和思路。     

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.     

高速公路ETC密钥管理系统研究

密钥管理系统(KMS)是电子不停车收费系统(ETC)中的一个关键子系统。文章介绍了密钥管理系统的加密算法、功能需求、程序执行过程、结构设计及软件模块,阐述了密钥管理系统的编程开发与应用情况。     

The Impacts of Ict on leisure Activities and Travel: A Conceptual Exploration

This paper offers a conceptual exploration of the potential impacts of ICTs on leisure activities and the associated travel. We start by discussing what leisure is and is not. We point out that the boundaries between leisure, mandatory, and maintenance activities are permeable, for three reasons: the multi-attribute nature of a single activity, the sequential interleaving of activity fragments, and the simultaneous conduct of multiple activities (multitasking). We then discuss four kinds of ways by which ICT can affect leisure activities and travel: the replacement of a traditional activity with an ICT counterpart, the generation of new ICT activities (that may displace other activities), the ICT-enabled reallocation of time to other activities, and ICT as a facilitator of leisure activities. We suggest 13 dimensions of leisure activities that are especially relevant to the issue of ICT impacts: location (in)dependence, mobility-based versus stationary, time (in)dependence, planning horizon, temporal structure and fragmentation, possible multitasking, solitary versus social activity, active versus passive participation, physical versus mental, equipment/media (in)dependence, informal versus formal arrangements required, motivation, and cost. The primary impact of ICT on leisure is to expand an individual’s choice set; however whether or not the new options will be chosen depends on the attributes of the activity (such as the 13 identified dimensions), as well as those of the individual. The potential transportation impacts when the new options are chosen are ambiguous.     

连续梁桥支座更换关键技术研究

文章针对目前常用的梁桥支座更换方法存在的问题,提出了一种适合连续桥梁支座更换的新思路,并通过仿真实验分析,验证了该方法的可行性。同时,文章提出了与该方法相适应的三种施工工艺,并对支座更换过程中施工控制的关键技术进行了探讨。     

The impact of private autonomous vehicles on vehicle ownership and unoccupied VMT generation

With 36 ventures testing autonomous vehicles (AVs) in the State of California, commercial deployment of this disruptive technology is almost around the corner (California Department of Transportation, 2016). Different business models of AVs, including Shared AVs (SAVs) and Private AVs (PAVs), will lead to significantly different changes in regional vehicle inventory and Vehicle Miles Travelled (VMT). Most prior studies have already explored the impact of SAVs on vehicle ownership and VMT generation. Limited understanding has been gained regarding vehicle ownership reduction and unoccupied VMT generation potentials in the era of PAVs. Motivated by such research gap, this study develops models to examine how much vehicle ownership reduction can be achieved once private conventional vehicles are replaced by AVs and the spatial distribution of unoccupied VMT accompanied with the vehicle reduction. The models are implemented using travel survey and synthesized trip profile from Atlanta Metropolitan Area. The results show that more than 18% of the households can reduce vehicles, while maintaining the current travel patterns. This can be translated into a 9.5% reduction in private vehicles in the study region. Meanwhile, 29.8 unoccupied VMT will be induced per day per reduced vehicles. A majority of the unoccupied VMT will be loaded on interstate highways and expressways and the largest percentage inflation in VMT will occur on minor local roads. The results can provide implications for evolving trends in household vehicles uses and the location of dedicated AV lanes in the PAV dominated future.     

The net effects of the built environment on household vehicle emissions: A case study of Austin,TX

Growing concerns over climate change have led to an increasing interest in the role of the built environment to reduce transportation greenhouse gas (GHG) emissions. Many studies have reported that compact, mixed-use, and well-connected developments reduce vehicle miles traveled (VMT). Others, however, argue that densification and mixture of land uses can slow down vehicle movements, and consequently generate more driving emissions. Methodologically, VMT is only a proxy, not an exact measure of emissions. This study quantifies the net effects of the built environment on household vehicle emissions through a case study of Austin, TX. The study employed structural equation modeling (SEM) techniques and estimated path models to improve understanding of the relationship between the built environment and vehicle emissions. The results show a rather complex picture of the relationship. Densification can reduce regional vehicle emissions despite its secondary effect of reduced vehicle travel speed. A 1% increase in density was found to reduce household vehicle emissions by 0.1%. However, intensification of the design feature of the built environment in developed areas may work in the opposite direction; the modeling results showed a 1% increase in grid-like network being associated with 0.8% increase in household vehicle emissions. Based on the results, the study addressed the potential of and the challenges to reducing vehicle emissions through modifying the built environment in local areas.