A data-driven dynamics simulation framework for railway vehicles

The finite element (FE) method is essential for simulating vehicle dynamics with fine details, especially for train crash simulations. However, factors such as the complexity of meshes and the distortion involved in a large deformation would undermine its calculation efficiency. An alternative method, the multi-body (MB) dynamics simulation provides satisfying time efficiency but limited accuracy when highly nonlinear dynamic process is involved. To maintain the advantages of both methods, this paper proposes a data-driven simulation framework for dynamics simulation of railway vehicles. This framework uses machine learning techniques to extract nonlinear features from training data generated by FE simulations so that specific mesh structures can be formulated by a surrogate element (or surrogate elements) to replace the original mechanical elements, and the dynamics simulation can be implemented by co-simulation with the surrogate element(s) embedded into a MB model. This framework consists of a series of techniques including data collection, feature extraction, training data sampling, surrogate element building, and model evaluation and selection. To verify the feasibility of this framework, we present two case studies, a vertical dynamics simulation and a longitudinal dynamics simulation, based on co-simulation with MATLAB/Simulink and Simpack, and a further comparison with a popular data-driven model (the Kriging model) is provided. The simulation result shows that using the legendre polynomial regression model in building surrogate elements can largely cut down the simulation time without sacrifice in accuracy.     

Active control strategy for the running attitude of high-speed train under strong crosswind condition

This paper focuses on the safety of high-speed trains under strong crosswind conditions. A new active control strategy is proposed based on the adaptive predictive control theory. The new control strategy aims at adjusting the attitudes of a train by controlling the new-type intelligent giant magnetostrictive actuator (GMA). It combined adaptive control with dynamic matrix control; parameters of predictive controller was real-time adjusted by online distinguishing to enhance the robustness of the control algorithm. On this basis, a correction control algorithm is also designed to regulate the parameters of predictive controller based on the step response of a controlled objective. Finally, the simulation results show that the proposed control strategy can adjust the running attitudes of high-speed trains under strong crosswind conditions; they also indicate that the new active control strategy is effective and applicable in improving the safety performance of a train based on a host–target computer technology provided by Matlab/Simulink.     

LNG-汽油两用燃料轿车改装技术研究

为解决LNG燃料在轿车上的使用,针对一富康轿车进行了LNG-汽油两用燃料改装研究。在保留原有汽油供油系统基础上,制定了加装LNG燃料系统的改装方案和专用装置选配,并对其电控系统进行了标定。对样车进行改装前、后性能对比试验表明,选配的各部件满足该车使用性能要求,改装后的LNG轿车动力性满足国家标准,排放效果优于原汽油车,经济性有大幅度提升,改装成本能够较快回收。     

客运专线预制箱梁梁场平移方式的分析比较

对客运专线预制箱梁滑移式、轮轨式、吊移式等3种平移方式进行对比分析介绍,总结出不同方式的优缺点,为客运专线预制梁场箱梁平移方式的选择提供参考。     

基于GPRS的多点无线实时温度检测系统

针对传统温度检测系统中存在的温测上限低、功耗大、传输速率低等问题，采用新型薄膜铂温度传感器设计了一种基于GPRS的多点无线实时温度检测系统，并使用正反馈型线性校正电路进一步提高了系统的测量准确度。多次测试结果表明，该系统具有高度的准确性、灵敏性和实用性。     

《摩托车电子控制燃油喷射系统(EFI)技术条件》标准的研究与制定

为适应国内外市场的需求变化,我国摩托车产品在面临产品质量提升、技术水平升级压力的同时, 也面临着适应国家日益严格的环保及节能降耗要求, 这需要对摩托车产品采用各种可行技术予以升级换     

下穿飞机跑道地铁区间隧道附加荷载计算方法

为更加准确方便地计算飞机滑行过程中对下穿飞机跑道的地铁区间隧道最不利作用位置的附加荷载值，将飞机22个轮子的最不利滑动荷载峰值作为飞机静荷载作用集中力，运用布辛奈斯克理论公式求解22个轮载作用下的地层附加应力值，分析不同埋深条件下最大竖向附加应力的分布规律和量值变化规律。根据荷载-结构法与飞机附加应力的理论解，确定下穿飞机跑道地铁区间隧道附加荷载的最不利分布模式，并通过回归分析得到飞机附加应力q1、q5的简化计算公式。最后通过数值模拟的方法验证了布辛奈斯克理论公式的适用性。研究结果表明： 1）随着隧道埋深的增大，飞机最大竖向附加应力与隧道竖向围岩压力的比值先迅速下降，随后缓慢下降，当隧道埋深大于50 m时，飞机最大竖向附加应力与竖向围岩压力的比值较小； 2）不同隧道埋深下的飞机最大竖向附加应力值点位置基本一致，位于距离飞机最后一排轮子2.1~3.3 m的中轴线上； 3）飞机附加荷载最不利分布模式为近似对称梯形分布模式，此时飞机最大竖向附加应力值点位于隧道拱顶正上方； 4）简化后的附加应力q1与隧道埋深z呈负相关关系，q5与隧道埋深z、隧道洞径D呈负相关关系。     

地铁再生制动能量吸收装置

以往采用车辆吸收电阻吸收地铁列车运行过程中的再生能量,这就带来隧道和站内的温升问题,同时导致车体重量增加,造成大量的能源浪费并使地铁的建设费用和运行费用增加.为解决这一系列问题,有必要对再生能量吸收的相关技术进行系统研究.首先分析了电阻耗能型吸收装置的工作原理及功能,在此基础上设计了主电路,然后详细讨论了装置的控制策略,最后利用PSIM对系统进行了仿真,验证了系统方案的可行性.     

SS9G电力机车主变压器潜伏性故障的分析和诊断

介绍发现某SS9G电力机车主变压器故障的过程。通过分析变压器油气相色谱的异常数据,介绍如何判断主变压器故障,以及结合电气试验如何判断主变压器故障类型和故障点。在分析主变压器故障原因的基础上,提出防范措施。     

论川江高速客运新船型开发

简介了川江高速客船现状,针对川江具体航线,分析了各类调整船优缺点。从水、陆、空综合交通合理分工出发,认为水上调整客运不会因为高速公路的发展而淘汰,仍有发展前途,关键是要开发、研制适合航线,其航行性能、结构强度、舒适性、经济性均比现有高速客船优越的新船型。