Speed profile estimation using license plate recognition data

Vehicle speed profile is a fundamental data support for calculating vehicular emission using the micro-emission model. However, achieving accuracy and breadth for the speed profile estimation is difficult. This study proposes a new vehicle speed profile estimation model using license plate recognition (LPR) data. This model allows speed profile estimation of every individual vehicle between two consecutive intersections. A systematic LPR data-mending method is developed to infer the information of unmatched vehicles. Using the complete arrival and departure information as boundary conditions, a customized car-following model combined with dummy-overtaking hypothesis and boundary constraints is then applied to estimate the speed profile of vehicles. The proposed model is validated using ground truth speed information from a field experiment conducted in Langfang City in China. Results show that the model can fully capture the pattern of ground truth speed profile. A complementary model validation using the Next Generation Simulation dataset and a model application for calculating emissions are also conducted. The numerical results indicate the effectiveness of the proposed model in estimating vehicle speed profile and emissions.     

铜管路件焊缝致密度检验方法研究

铜管路件主要由铜管及三通接头焊接而成,焊接的质量对水冷系统有很大的影响。本文研究了铜管路件焊缝致密度的检验方法,介绍了铜管路件焊接方法、影响焊接质量的各种因素及焊接工艺过程。提出了铜管路件焊缝致密度检验方法,该方法首先对检验样本进行制备,接着通过由光学显微镜与计算机组成的成像系统对样本焊缝位置进行显微图像采集,对采集到的焊缝显微图像在图像软件中进行处理,获取焊缝缺陷的长度,从而计算焊缝位置的致密度。     

A scalable communication middleware for real-time data collection of dangerous goods vehicle activities

Recently, real-time monitoring of Dangerous Goods Transport has drawn a lot of attention, thanks to its capability to provide a better visibility on dynamically moving vehicles, particularly through a Web Mapping application. Yet, one of the challenges to be faced designing such a system is an effective architecture for real-time collection of telemetry and event data conveyed by the vehicle on-board system, such the Global Positioning System coordinates. In this paper, we have focused on optimizing the process for managing a large quantity of data transmitted via network sockets that use the Transmission Control Protocol. Then we prove the process efficiency through performance and scalability tests. The middleware is being implemented as a part of a project that aims to monitor the Italian petrochemical company Eni’s oil trucks shipment along Europe and USA territories.     

电子束焊接在我国汽车工业中的应用现状及展望

指出小到发动机火花塞。大到汽车后桥等几十种汽车零部件都可以采用电子束焊接，分析了电子束焊接在我国汽车行业的应用现状，对相关设备，技术行，工艺进行了较详尽的论述；对我国汽车工业进一步应用电子焊接技术进行了展望。     

微型剪切试验法及基在焊接技术中的应用

本文介绍一种研究金属材料机械性能的新型试验方法——微型剪切试验以及它在焊接技术中的应用。     

Study on the Formation of η Phase During TIG Welding

The paper studied the effect of Ni-Fe-C filler materials on the η phase formation during TIG welding of WC-30Co and 45 steel. ηphase's morphology and forming condition were discussed using BEI method. The properties of the weld joints were also measured using microhardness measurement and four-point bending measurement. The results show that the weld joints of WC-30Co/45 steel can be obtained by TIG welding using different Ni-Fe-C materials as filler materials, and ηphase formed in the joints is M6C, M12C type carbides. The poor carbon content of the W-Co-C system resulted from the C diffusion and the high ingredient Fe are the two vital factors inducing to ηphase formation. It can be restricted by the addition of C element into Ni-Fe material. When carbon content is 0.01 % in filler material, bend strength σbb of weld joint is 908 MPa. However, when carbon content increases to 0. 41% in filler material, bend strength σbb is 1 260 MPa.     

激光重熔含25%WC的铁基合金涂层的研究

利用高能量密度的激光束重熔含25％WC的铁基合金涂层时,提高激光束能量密度有利于重熔层的成形,但是能量密度太高时,重熔层组织中的WC硬质相发生溶解。因此,必须选择合适的激光重熔工艺参数。在本试验条件下合适的工艺参数是:激光功率2.5kW、扫描速度25mm/s,激光束宽度4mm,激光重熔层的显微组织中的CrB、Cr_(22)C_6等微粒硬质相的存在使镶嵌WC的基体组织得到强化。激光重熔含25％WC的铁基合金涂层的抗脆断性能及其与基材的结合性能和抗磨粒磨损性能都明显地优于火焰喷涂层和火焰重熔层。     

活性化焊剂成分对A—TIG焊缝成形的影响

采用活性化焊剂TIG焊接方法研究了奥氏体不锈钢焊缝熔深的变化。结果表明：在相同焊接工艺参数下，活性化焊剂成分、活性化焊剂涂层厚度对焊缝成型有显影响。与单一成分相比，混合型助焊剂，特别是加稀土的混合助焊剂可使焊缝熔深显增加。     

电阻点焊电极表面处理的研究现状和展望

简要介绍了点焊电极表面处理的方法,对涂层材料的要求、点焊电极失效机理以及涂层材料对点焊电极失效机理的影响;另外介绍了点焊电极表面处理的发展方向。     

基于最大输出功率的高效钢轨交流闪光焊工艺

针对目前国内大量使用的К型交流钢轨闪光焊机,根据焊接主回路等效电路建立了最大功率输出和高效焊接控制的数学模型,编制了过程控制程序.采用К900钢轨焊机设置不同的高压阶段焊接电流进行试验,以测量在相同烧化量时的高压阶段时间.试验表明,当高压阶段焊接电流接近设备最大功率输出的焊接电流时,高压阶段焊接时间较短.在高压阶段和低压阶段的前期,采用基于最大输出功率的高效焊接控制模型,可以快速加热钢轨,缩短焊接时间,提高焊接生产率.