汽车传动系阻力台架检测和评价方法

为准确检测和评价汽车传动系的技术状况,在50km/h车速点,按GB/T18566-2011《道路运输车辆燃料消耗量检测评价方法》的基准温度车轮滚筒阻力系数厂fc,以试验统计技术状况良好车辆的传动系阻率η,计算所检车辆规定车速点的额定传动系台架阻力,然后在底盘测功机上检测基准温度状态下车辆实际传动系台架阻力,把实际阻力与额定阻力比较来检测和判断车辆传动系的技术状况。     

迈腾B7L电子节气门故障

<正>车型:迈腾B7L,配置2.0LTSI发动机(CGM)。VIN:LFV3A23C6C×××××××。行驶里程:28000km。故障现象:发动机启动后只能怠速运转,踩加速踏板,转速无法提升。故障诊断:利用ODIS诊断仪,检查发动机电控系统存在故障码:◆P0641:传感器基准电压"A"断路◆P0651:传感器基准电压"B"断路◆P1545:节气门控制功能失效◆P2106:节气门控制单元J338由于系统故障功率受限     

白车身焊接误差原因及控制方法

<正>白车身焊接精度关系到整车装配的匹配性和整车的安全性,所以有效地控制、提高白车身的焊接精度,是整车质量的重要保证。本文主要对汽车焊接误差产生的原因进行分析,并提出合理的控制方法,从而为今后白车身制造中降低焊接误差提供参考。     

摩巴大连公司挖掘机辅助系统

MOBA公司采用全球卫星定位技术与丰富的控制软件相结合,专门针对挖掘机开发了辅助引导系统。通过建立数字化地面基准模型,为传统施工中遇到的种种问题提供全新、高效的技术解决方案。即使在视力不及的盲区（例如在水下）,铲斗也能精确完成工作,彻底改变了人们对挖掘机传统施工方式的认识。在现场无需测量放样的情况下,可以精确完成多种坡度、深度及河道横断而轮廓的修整挖掘工作,大大提高了机器施工的精度、效率,可为承包商节省大量的人员、时间、物资和金钱。     

悬索桥基准索股架设若干影响因素分析与控制

采用数值解析法对悬索桥基准索股架设时因温度、跨径、索塔高度及索长变化引起的主跨中标点高程改变进行了研究,得到了各种影响因素在发生单位变化量时产生主揽跨中标志点标高的的影响值,提出了受各因素影响下基准索股施工架设的修正方法。实践证明:数值解析法对于现场确定和控制基准索股的高程非常有效。     

桥梁检测和状态评估技术的研究与应用

随着我国经济的快速发展,我国桥梁建设发展迅速,但随着时间的推移．越来越多的桥梁达到或接近设计基准期．有的是因为很多不同的原因导致桥梁损坏．有的已经慢慢地老化．这严重影响到交通运输的安全。     

Damping of Oblique Ocean Waves by a Vertical Porous Structure Placed on a Multi-step Bottom

Oblique ocean wave damping by a vertical porous structure placed on a multi-step bottom topography is studied with the help of linear water wave theory. Some portion of the oblique wave, incident on the porous structure, gets reflected by the multi-step bottom and the porous structure, and the rest propagates into the water medium following the porous structure. Two cases are considered： first a solid vertical wall placed at a finite distance from the porous structure in the water medium following the porous structure and then a special case of an unbounded water medium following the porous structure. In both cases, boundary value problems are set up in three different media, the first medium being water, the second medium being the porous structure consisting ofp vertical regions-one above each step and the third medium being water again. By using the matching conditions along the virtualvertical boundaries, a system of linear equations is deduced. The behavior of the reflection coefficient and the dimensionless amplitude of the transmitted progressive wave due to different relevant parameters are studied. Energy loss due to the propagation of oblique water wave through the porous structure is also carried out. The effects of various parameters, such as number of evanescent modes, porosity, friction factor, structure width, number of steps and angle of incidence, on the reflection coefficient and the dimensionless amplitude of the transmitted wave are studied graphically for both cases. Number of evanescent modes merely affects the scattering phenomenon. But higher values of porosity show relatively lower reflection than that for lower porosity. Oscillation in the reflection coefficient is observed for lower values of friction factor but it disappears with an increase in the value of friction factor. Amplitude of the transmitted progressive wave is independent of the porosity of the structure. But lower value of friction factor causes higher transmission. The investigation is then carried out for the second ca     

Optimization of Wigley Hull Form in order to Ensure the Objective Functions of the Seakeeping Performance

The research performed in this paper was carried out to investigate the computational procedure to design seakeeping optimized ship hull form. To reach the optimized hull form, four stages should be done, which consists of： generate alternative hull form, seakeeping calculations, objective functions and optimization techniques. There are many parameters that may be determined in ship hull form optimization. This paper deals with developed strip theory for determining the seakeeping performance, genetic algorithm （GA） as optimization method, high order equations for curve fitting of the hull form and finally reaching to the minimum bow vertical motion in regular head waves. The Wigley hull is selected as an initial hull and carried to be optimized. Two cases are considered. For the first case, the only form coefficients of the hull （CB, CM, Cw, Cp） are changed and main dimensions （L, B, 7） are fixed. In the second case both hull form and main dimensions are varied simultaneously. Finally, optimized hull form and its seakeeping performances are presented. The results of optimization procedure demonstrate that the optimized hull forms yield a reduction in vertical motion and acceleration.     

微波信号LTCC多层互连设计

不同平面的微波信号低插损互连过渡已成为决定三维T/R组件性能优劣的关键问题之一,论文针对此问题介绍了一种窄带微波信号多层互连设计.该设计使用通孔垂直互连和带状线-微带线过渡,将电磁波从顶层微带线传输到底层微带线,从而完成异面微波信号互连.该设计运用三维高频电磁仿真软件HFSS建立并对比分析了三种模型,最后综合工艺难度和仿真结果挑选出最优方案加工成实物.经测试得到：在12GHz～18GHz范围内,插损小于0.9dB,回波损耗大于12dB,与仿真结果基本一致.实验结果表明,该结构具有尺寸小、插损低、应用范围广等特点.     

基于智能数据融合的车内噪声主动控制算法

为解决车辆噪声主动控制系统中参考信号在车内容易受到次级声源的污染和以发动机转速信号作为参考只能控制发动机阶次噪声的问题,提出一种基于智能数据融合的车内噪声主动控制算法。首先根据传递路径分析结果选择对车内噪声贡献量大的车外测点信号,然后将发动机转速信号和车外测点信号进行数据融合作为参考信号,再利用迭代变步长FxLMS算法对驾驶员耳侧噪声进行主动控制。基于试验采集的不同工况车内噪声进行仿真分析,结果表明,所提出的算法相较于采用发动机转速信号作为参考信号的方法在总声压级上降低了4.4 dB(A)。