汽车行驶平顺性评价方法研究及仿真分析

汽车平顺性是汽车NVH性能的评价指标之一。系统介绍了汽车行驶平顺性的客观评价方法,并结合某车型搭建整车行驶平顺性虚拟样机,进行了仿真分析评价。该方法可用于指导汽车行驶平顺性的改善以及悬架参数的优化。     

轿车悬架空间五连杆机构尺度综合

对轿车悬架五连杆机构进行自由度计算；论述应用位置反解方程进行该机构刚体导引尺度综合的一般方法；指出轮轴构件作圆弧轨迹平动时能使车轮轨迹角不变；阐述进行该机构尺度综合的设计计算方法；由算例得到一组与实际相符的位置与结构参数值，供悬架设计时参考。     

受电弓—刚性接触悬挂系统受流特性分析

建立受电弓—刚性接触悬挂系统受流模型和振动微分方程组,采用Newmark-β法编制受电弓—刚性悬挂系统振动微分方程的数值仿真程序,利用Matlab仿真软件分析刚性悬挂、受电弓参数对受电弓—刚性接触网系统动态受流的影响,得到给定技术条件下的受电弓最优参数。     

自主创新通用安全计算机平台与欧标认证

安全计算机被广泛应用于轨道交通信号系统。着重介绍自主研发的通用安全计算机平台,并对安全计算机的可靠性和安全性设计进行了说明。为确保安全计算机能够达到安全完整性等级4级的要求,根据欧洲系列安全标准的理念,研发过程不仅采用适当的技术手段,同时创新性地增加了安全管理手段。引入独立第三方的欧标安全认证,有效地证明了平台的安全性。     

门型桥塔驰振气动干扰效应数值模拟

针对大跨径悬索桥施工期门型变截面桥塔的驰振问题,提出一种有限元与计算流体动力学CFD相结合分析变截面高耸结构驰振的实用数值方法。以东海某大跨径悬索桥北桥塔为例,运用该方法,考虑塔柱间的气动干扰效应,进行门型桥塔施工期典型工况的驰振性能分析。结果表明:纵桥向门型桥塔整体和其单根塔柱的驰振力系数均大于0,不存在驰振失稳的可能性;在横桥向,由于门型桥塔受塔柱间气动干扰效应的影响,其驰振性能与不考虑气动干扰时的不同,且倒角截面对门型桥塔驰振性能不利;矩形截面和倒角截面前柱的驰振力系数均大于0,后柱的驰振力系数均存在小于0的情况,且后柱驰振力系数的绝对值大于门型桥塔整体的驰振力系数绝对值;在进行门型桥塔施工期驰振分析时,当无横梁时,要重点研究后柱横桥向的驰振性能。     

基于再次均匀采样策略改进轨道车辆二系悬挂系统参数估计方法

基于粒子滤波和卡尔曼滤波的轨道车辆二系悬挂系统参数估计方法存在因粒子枯竭而无法对系统参数变化进行监测的缺陷,所以引入再次均匀采样策略对其进行改进.采用轨道车辆系统横向动力学模型,建立轨道车辆二系悬挂系统的横向动态空间模型,并运用改进后的参数估计算法和Matlab软件对二系横向阻尼和抗蛇行阻尼2个系统参数进行仿真计算.结果表明:在无法获得轨道横向不平顺统计特性的情况下,参数估计方法仍具有良好的鲁棒性;在轨道车辆二系悬挂系统发生突发或老化故障的情况下,改进后的参数估计方法可以准确估计系统参数的变化,且误差值始终保持在10％以下,能够实现对系统状态的实时监测.     

兰新高铁大风区接触网正馈线悬挂结构适应性分析

试验和运行经验表明,兰新高铁大风区接触网正馈线(AF线)疲劳磨损问题非常突出。通过理论结合实际的方法,利用有限元三维流体场仿真辅助手段,分析百里、三十里风区挡风墙后方大风运动特征及AF线风场内受挡风墙结构增速影响的运动特点,提出AF线受激励源干扰产生大幅振动的机理。利用现场样本空间数据累计及AF线V形悬挂铰接零部件的运动频次,提出AF线V形悬挂结构合理性设计的关键点及结构匹配重要性,以及限制零部件间磨损的有效措施。     

基于独立分量分析的诱发电位信号提取方法

诱发电位（EP）信号在检测神经系统状态时有重要意义，但EP信号总是没在自发脑电波（EEG）信号中，因此，为利用EP信号诊断神经系统的损伤和病变，需要从二的混合信号中提出EP信号。独立分量分析（ICA）是一种新近发展起来的信号分离方法。本反ICA方法应用于EP信号的提取，并与传统的滤波方法进行了比较。计算模拟表明，采用ICA方法进行噪声分离的结果明显优于信号滤波方法。     

Investigation of hardware-in-the-loop for use in suspension development

Hardware-in-the-loop (HiL) is a testing method in which real-time measurements on physical hardware replace the mathematical model of the particular hardware during simulation. The development of a semi-active suspension prompted the need for such capability. HiL, implemented on a PC with a dSpace^TM board in conjunction with a hydrodynamic actuator, was compared to software simulations of single degree of freedom (DOF) and two DOF systems. HiL was also compared to a physical (ballast-based) two DOF system, comprising the rear suspension of a motorcycle. Comparisons between the HiL and software responses showed its suitability for testing suspension systems, thus providing a viable alternative to ballast-based suspension tests, using available hardware. The research also showed that actuator dynamics, filter types and amounts, and signal reference levels required special consideration.     

How much can public private partnership really do for urban transport in developing countries?

A few cities in some of the larger developing countries in Latin America and Asia have made increasing use of multi-year concessions or franchises, competitively awarded to private companies, for construction and operation of urban transport infrastructure and for provision of public transport services. In view of the strong prospective growth of developing-country cities with large transport needs, and the rise in the emerging economies of potential new sources of private capital, it is important to see how effective PPP has so far been in this area. The experience is analyzed principally by thorough comparative review of what has actually happened for some of the main users to date: Bogotá, Santiago, São Paulo, Seoul, and several cities in both China and India. Despite delays and mistakes that have been made in development of most of the projects, the overall results, already delivered and in prospect, are very positive and urban public transport is benefiting substantially, with significant side effects on poorer people's access to work and to services, air pollution levels and road accident rates. The widest and most important advantage of the PPP arrangements, as compared with more conventional short-term contracting, is found to be the innovations, technical and managerial, developed, and, in particular, the mutual capacity building of the countries' private and public sectors and their more effective interaction. The experience in the six countries covered suggests that other developing-country cities may be best assisted to develop sound urban transport PPPs more rapidly through provision of help on chosen items among 7 elements that have proved particularly crucial but sometimes weak in the projects reviewed: Civic consultation systems, Land-use/Transport strategic planning, Land/property market management, Monitoring systems, Progressive policies, Economic regulation, and Public institutional framework for PPPs.