谈ZYJ7型转辙机道岔维修和调整的几点经验

本文对提速区段zYJ7型转辙机道岔在现场使用和维护中易出现的主要问题，进行系统地分析，并提出了解决方案，使提速道岔故障大幅下降，确保提速区段的运输安全、畅通。     

高速公路基础测绘控制测量中的重点问题探讨

针对高速公路基础测绘平面和高程控制测量,提出了应予以重点关注的控制等级、点位布设、观测方法、数据处理、坐标系确定、三角高程测量、GPS高程转换等问题,并给出了如何解决上述问题的思路和方法。     

抗车辙剂对沥青性能的影响及离析分析

通过试验,分析了抗车辙剂掺量对沥青软化点、针入度、低温延度和峰值拉力的影响,并对比同一抗车辙剂掺量上下层沥青各指标间的差异。试验结果表明:同一层沥青,随着抗车辙剂掺量的增大,软化点和峰值拉力逐渐增大,而针入度和低温延度逐渐减小;当抗车辙剂掺量相同时,上层沥青的软化点和峰值拉力大于下层沥青,针入度和低温延度小于下层沥青;抗车辙剂掺量越大,上下层沥青各指标差距越明显,沥青越容易发生离析。     

Estimation of the vehicle's centre of gravity based on a braking model

A vehicle's centre of gravity (CG) is an important property that affects the vehicle's handing stability, ride comfort and safety. For example, a high CG may lead to a serious traffic accident due to the adverse effects it may have on roll and handling stability. In this paper, we develop a dynamic detection method to obtain vehicle's height that uses a simulation model based on a dynamic analysis during braking. Simulations show that the dynamic detection method is feasible. Experiments with three different vehicles are performed to verify the proposed method. The previously established prediction detection and lifting detection (LD) methods are used for comparison. The experimental results demonstrate that the proposed method has higher accuracy and efficiency than the LD method. Thus, the proposed method is useful for the vehicle detection.     

路基设计横断面复测工程量及中间分次计量工程量计算

路基设计横断面复测及中间分次计量工作量计算比较复杂,通过对各种公路典型横断面分析,用圆的极限概念及工程近似概念,把横断面这个不规则图形分解成有限个规则的梯形,从而达到计算横断面面积及工程量的结果.     

Real-time multiple-model estimation of centre of gravity position in automotive vehicles

In this paper, we present a methodology based on multiple models and switching for real-time estimation of centre of gravity (CG) position in automotive vehicles. The method utilises well-known simple linear vehicle models for lateral and roll dynamics and assumes the availability of standard stock automotive sensors. We illustrate the technique with numerical simulations as well as with measured sensor data from an sport utility vehicle. We also compare our estimation results with traditional linear least-squares estimators to show the efficacy of our technique. Finally, we give a simple application example for implementing the idea in automotive vehicles as a switch for rollover controller activation.     

高压IGBT和无变压器牵引应用中多电平变流器的功率损耗评估

轨道车辆目前所使用的低频线路变压器受低效和超重问题所困.未来的牵引传动系统可能直接与电网相连,无需该类变压器.典型的无变压器传动系统通常由多个使用HV-IGBT(高压绝缘栅双极型晶体管)的中等电压规格变流器串联而成.设计之初先对6.5 kVIGBT和目前已商业应用于牵引领域的3.3 kV、4.5 kV IGBT的开关特性和损耗进行比较,基于所考虑的HV-IGBT,对多电平变流器的特点及其在无变压器系统的应用进行了评估.本文侧重于变流器的损耗分析,同时简要地探讨了可靠性和谐波频谱问题.综合考虑上述各方面因素,三电平中点箝位变流器是一种较理想的方案,适用于无变压器牵引系统,可作为网侧变流器和电机侧变流器使用.     

舰船重量重心控制系统设计

分析舰船重量重心设计中的流程和关键要素,以关系模型为基础,按照规范化理论要求进行了系统设计,利用最新的信息集成技术和数据库技术,实现舰船重量重心设计中的信息集成和智能化控制。     

道岔状态监测系统的研究

道岔尖轨密贴是行车安全的重要保证.随着我国铁路进入高速铁路的发展时期和行车密度的不断增加,采用以往的道岔养护方法,安排维修"天窗"与维修人员安全等方面的问题日益突出.道岔状态监测系统实时监测道岔动态信息,及时发现异常并报警,解决道岔养护问题.     

处于无潮区无潮点特殊海域的疏浚工程施工

挖泥船在无潮区无潮点的海域施工,因无潮位、流速大、土质硬等特点和特大风浪袭击的风险,常规的疏浚工程变成了具有危险性的特殊工程,通过采取适当措施,顺利完成了施工任务.在工程实施过程中,不但积累了宝贵的施工经验,还观测到粉砂液化现象,为港口选址提供了关键性的参考依据.