New insights from fractional order skyhook damping control for railway vehicles

Active suspensions for railway vehicles have been a topic of research for a number of decades and while their applications in service operation are limited, it seems clear that they will in due course see widespread adoption. Railway suspension design is a problem of compromise on the non-trivial trade-off of ride quality versus track following (guidance), and the skyhook damping control approach has been paramount in illustrating the potential benefits. Since skyhook damping control, various advanced control studies appeared contributing to redefine the boundaries of the aforementioned trade-off. Yet there is no study on the impact of fractional order (FO) methods in the context of skyhook railway active suspensions and in particular related to skyhook damping control. This is the area to which this paper strongly contributes. We present findings from a current project on FO controllers for railway vehicles active suspensions, in particular work on the effect of FO methods in basic skyhook damping control schemes, i.e. pure and intuitively based skyhook. First, we present a brief review of conventional skyhook damping control and then proceed to a rigorous investigation of the impact of FO on the ride quality/track following trade-off. The relevant benefits from FO methods are appraised and new insights highlighted.     

SW-220K型转向架参数优化试验研究

对配装SW—220K型转向架的25T型客车进行了振动试验;分析了车辆的主要振型;分别进行了采用不同空气弹簧、二系阻尼系数值时的试验,根据垂向、横向平稳性指标测试结果,得出了采用原型空气弹簧结构并增大二系垂向阻尼系数值能够改善车辆运行性能的结论。     

On-track test of tilt control strategies for less motion sickness on tilting trains

Carbody tilting is today a mature and inexpensive technology that permits higher train speeds in horizontal curves, thus shortening travel time. However, tilting trains run a greater risk of causing motion sickness than non-tilting ones. It is likely that the difference in motions between the two train types contributes to the observed difference in risk of motion sickness. Decreasing the risk of motion sickness has until now been equal to increasing the discomfort related to quasi-static lateral acceleration. But, there is a difference in time perception between discomfort caused by quasi-static quantities and motion sickness, which opens up for new solutions. One proposed strategy is to let the local track conditions influence the tilt and give each curve its own optimised tilt angle. This is made possible by new tilt algorithms, storing track data and using a positioning system to select the appropriate data. The present paper reports from on-track tests involving more than 100 test subjects onboard a tilting train. A technical approach is taken evaluating the effectiveness of the new tilt algorithms and the different requirements on quasi-static lateral acceleration and lateral jerk in relative terms. The evaluation verifies that the rms values important for motion sickness can be influenced without changing the requirements on quasi-static lateral acceleration and lateral jerk. The evaluation shows that reduced quantities of motions assumed to have a relation to motion sickness also lead to a reduction in experienced motion sickness. However, a limitation of applicability is found as the lowest risk of motion sickness was not recorded for the test case with motions closest to those of a non-tilting train. An optimal level of tilt, different from no tilt at all, is obtained. This non-linear relation has been observed by other researchers in laboratory tests.     

空气悬架客车平顺性分析与优化

以某空气悬置客车为原型,建立其多体动力学模型,分析悬架系统中非线性弹性与阻尼元件对平顺性能的影响,并结合ADAMS软件运算原理,提出一种适用于其求解器的插值拟合优化方法,运用灵敏度分析等手段重新匹配悬架的刚度与阻尼,以提高车辆的乘坐舒适性。     

北京市停车换乘需求调查与分析

停车换乘（Park＆Ride,简称P＆R）作为一种交通出行模式,在许多国外城市被采用。目前,我国北京市、上海市等城市均进行了停车换乘设施的规划和试点。本文基于对北京市天通苑北和巴沟两个停车换乘点的停车换乘需求调查,分析比较了停车换乘需求特性,结果表明：天通苑北和巴沟的机动车和非机动车驶入停车场的高峰时段均为早上7：00...     

空气弹簧对重卡平顺性影响研究

为使重卡在平顺性方面满足国际或国家法规要求,利用专用软件,在建立有限元模型的基础上,通过计算机线性静态模拟计算分析,建立重卡有限元模型,进行动态模拟分析和数据分析,从重卡的平顺性出发,通过对安装空气弹簧重卡平顺性实验,然后建立重型卡车ADMAS/Car虚拟样机模型,针对空气弹簧在重卡上的平顺性能影响进行仿真和试验对比分析,并提出改进建议以达到设计目标。     

路面平整度均方差指标与行车舒适性的关系研究

在研究路面平整度均方差指标与路面状态之定量关系的基础上,结合车辆在路面上行驶时所产生的振动对人体所产生的影响,分析研究了路面平整度均方差指标与行车舒适性之间的关系,得出平整度指标与行车舒适性之间具有一定关系,但是平整度指标的高低并不能完全代表行车舒适性的优劣.     

基于键图理论的汽车平顺性仿真分析

探讨键图理论用于汽车平顺性仿真分析的方法,将所建立的汽车四自由度振动键图模型与Matlab的Simulink仿真工具箱仿真方框图相连接,直接利用Simulink的可视化功能,实现汽车平顺性可视化仿真。键图模型和Simulink仿真工具箱的连接可使键图理论在汽车系统仿真分析研究中更为简便、快捷。     

城市客车七自由度平顺性模型仿真研究

建立某城市客车的七自由度平顺性模型,基于MATLAB/Simulink软件编写仿真程序和图形化界面,并进行仿真分析,将仿真结果与试验结果对比.     

平稳性快速算法及其在高速铁道车辆动力学分析中的运用

导出了轨道车辆基于虚拟激励原理的平稳性快速算法。当车辆系统受多点全相关随机激励时,首先基于虚拟激励法导出轨道车辆响应功率谱的简易算法,然后利用所获得的功率谱和反演技术,获得系统响应的幅值谱,由此可快速获得轨道车辆的平稳性指标。运用该算法还可以方便地分析轨道谱中单一波长对车辆运行平稳性的影响,以及定义和分析对平稳性有影响的线路敏感波长范围。以某型高速客车为例,分析了其垂向和横向的响应功率谱、平稳性指标,还利用反演技术获得了加速度的时域信号和幅值谱,最后分析了轨道谱中单一波长对车辆平稳性的影响。分析表明,运行速度越高,对平稳性影响的波长范围就越宽,线路的维护难度也越大。