GPS定位的调车系统

简要介绍了差分GPS原理和调车监控过程;阐述了利用GPS进行调车监控系统设计的基本思想和GPS调车监控系统的基本结构;详细论述了GPS调车监控车载系统的软件设计,其中特别强调了设计过程中如何利用线路元素将调车系统的监控功能、电子地图的实时显示功能有效地结合起来,以提高系统的通用性、可移植性和节省系统的存储空间;同时,对调车过程中的勾计划实现、十五三模式控制等作了简要介绍。     

车辆下线检测系统的开发

该车辆下线检测系统能够自动识别某汽车所采用的发动机ECU、AT和AMT变速器TCU、整车防盗设备IMMO、乘员保护系统SRS及ABS防抱刹车系统控制单元的型号,并采用虚拟仪器技术,实现各种电控单元的故障诊断、实时参数测量和执行器测试等功能。此检测系统在该汽车生产线上的应用表明,其可作为车辆下线前车载电子器件是否正常工作的判断依据,并可同时提供车辆车况跟踪、统计和分析的实测数据。     

基于USB的列车车载类设备软件升级技术研究

为解决列车车载类设备软件升级困难的问题,研究了基于USB的列车车载类设备软件升级技术,提出一种传输速度更快、稳定性更高、操作更方便的车载设备软件离线升级方法,该方法以IAP(In Application Programming)技术为基础,以处理器内部Flash为存储载体,利用基于USB通信协议设计的底包程序实现了设备的软件升级。该技术方法已应用于故障诊断等车载设备软件的升级,有效提高了软件升级效率。     

Development of super element to perform direct analysis on failure assessment of hull structures based on FAD

Failure assessment diagram (FAD) has great potentials to be a powerful tool to assess the integrity of hull structures. However, the current methodology to obtain the fracture ratio and the load ratio, two axes of FAD, for hull structures is tedious and burden which is one of the major obstacles to advance the further application of FAD. In this paper, a super element is introduced to obtain those two ratios simultaneously in the framework of linear elastic analysis within a single step. Besides, the virtual section closure technique is proposed to compute the reference stress under the inspiration of virtual crack closure technique to compute the stress intensity factor. The capacity of the proposed super element has been assessed by two classic examples of a plate with central crack and a cylinder with circumferential crack. The results obtained from the super element are compared to the corresponding analytical solutions. Finally, the cracked Nishihara specimen (NST-3) was examined and the facture ratio and the load ratio obtained by the super element were compared to those obtained by the global analyses. The comparisons indicate that the proposed super element is accurate. No convergence troubles were encountered. Therefore, the methodology developed in this paper could be a very useful addition to perform the direct analysis on the failure of hull structures due to large crack extensions based on the failure assessment diagram.     

Numerical study on fatigue crack growth at a web-stiffener of ship structural details by an objected-oriented approach in conjunction with ABAQUS

It is necessary to manage the fatigue crack growth (FCG) once those cracks are detected during in-service inspections. This is particular critical as high strength steels are being used increasingly in ship and offshore structures. In this paper, a simulation program (FCG-System) is developed utilizing the commercial software ABAQUS with its object-oriented programming interface to simulate the fatigue crack path and to compute the corresponding fatigue life. In order to apply FCG-System in large-scale marine structures, the substructure modeling technique is integrated in the system under the consideration of structural details and load shedding during crack growth. Based on the nodal forces and nodal displacements obtained from finite element analysis, a formula for shell elements to compute stress intensity factors is proposed in the view of virtual crack closure technique. Neither special singular elements nor the collapsed element technique is used at the crack tip. The established FCG-System cannot only treat problems with a single crack, but also handle problems with multiple cracks in case of simultaneous but uneven growth. The accuracy and the robustness of FCG-System are demonstrated by two illustrative examples. No stability and convergence difficulties have been encountered in these cases and meanwhile, insensitivity to the mesh size is confirmed. Therefore, the FCG-System developed by authors could be an efficient tool to perform fatigue crack growth analysis on marine structures.     

Total water requirements of passenger transport modes

With a growing urban population, it is crucial to maintain and develop environmentally friendly transport modes. However, while one of the most important indicators of environmental performance is water use, very few studies have quantified the total water requirements associated with different transport modes.This study uses input-output analysis to quantify the total water requirements of different passenger-transport modes in Melbourne, Australia, including the direct and indirect water requirements of petrol cars, regional diesel trains and electric metropolitan trains.Results show that urban electric trains are the least water intensive transport mode (3.4 L/pkm) followed by regional diesel trains (5.2 L/pkm) and petrol cars (6.4 L/pkm). These intensities result in average daily per capita transport-related water use that can be greater than residential water use. Findings also show that occupancy rates greatly affect the water intensity of transport modes and that when occupied by five passengers, cars are the least water intensive transport mode. Finally, this study shows that water use associated with transport depends on a range of factors across the supply chain and that indirect requirements associated with operations, including administration, advertisement, servicing and others, can represent a significant share of the total. Reducing the total water requirements of transport modes is therefore a shared responsibility between all the actors involved and integrated action plans are needed in order to reduce water use associated with transport.     

Experimental Economics and choice in transportation: Incentives and context

This paper reviews the preconditions for successful applications of Experimental Economics methods to research on transportation problems, as new transportation and research technologies emerge. We argue that the application of properly designed incentives, the hallmark of Experimental Economics, provides a high degree of experimental control, leading to internal validity and incentive compatibility. Both of these are essential for ensuring that findings generalize to contexts outside the immediate application. New technologies, such as virtual reality simulators, can generate external validity for the experiments by providing realistic contexts. GPS and other tracking technologies, as well as smart phones, smart cards and connected vehicle technologies can allow detailed observations on actions and real-time interactions with drivers in field experiments. Proper application of these new technologies in research requires an understanding of how to maintain a high level of internal validity and incentive compatibility as external validity is increased. In this review of past applications of Experimental Economics to transportation we focus on their success in achieving external and internal validity.     

基于DSP和USB的图像采集系统的研究

论述了一种基于USB的VGA图像数据处理系统的硬件设计及软件程序的编写，采用AD9884A对图像数据进行数字转换，利用DSP进行小波变换处理，接口部分采用Cypress公司的CY68013传输数据到PC机或SL811HS存储到移动硬盘．文中简单介绍了AD9884A芯片的特点、USB芯片的功能及其主、从传输模式下的程序设计．     

虚拟现实技术在教育领域的应用前景

作者从软件硬件方面介绍了目前VR技术的基本发展状况,并提出了一个基于VR技术的虚拟学习伙伴系统的实施方案,分析了它的实现可能性,阐述了它的特点及实现步骤。     

HID电子镇流器在船用高压钠灯中的应用

船舶照明包括船用防爆强光灯、防爆泛光灯、航行灯、室内、机舱照明、应急照明等等,按2004年底的国内水上运输船舶的拥有量21.1万艘,来计算船舶的照明耗电量将是一个巨大的数字,如何在使用、设计、改造中节约船舶照明的能耗,将是我国推广绿色照明的一个重要组成部分。高压钠灯是HID灯的一种,高压钠灯使用时发出金白色光,它具有发光效率高、耗电少、寿命长、透雾能力强和不诱虫等优点。广泛应用于船舶、码头、船坞、道路、高速公路、机场。镇流器是气体放电灯工作时必不可缺的配套附件,因此合理设计配套HID灯用的电器附件是非常重要的,本文主要讨论电子镇流器的节能效应和发展趋势。