The effect of controllable train-tail devices on the longitudinal impulse of the combined trains under initial braking

The 20,000-ton combined train running has greatly promoted China’s heavy-haul railway transportation capability. The application of controllable train-tail devices could improve the braking wave of the train and braking synchronism, and alleviate longitudinal impulse.However, the characteristics of the controllable train-tail device such as exhaust area, exhaust duration and exhaust action time are not uniform in practice, and their effects on the longitudinal impulse of the train are not apparent,which is worth studying. In this work, according to the formation of the Datong-Qinhuangdao Railway, the train air brake and longitudinal dynamics simulation system(TABLDSS) is applied to establish a 20,000-ton combined train model with the controllable train-tail device, and the braking characteristics and the longitudinal impulse of the train are calculated synchronously with changing the air exhaust time, exhaust area, and action lag time under initial braking. The results show that the maximum coupler force of the combined train will decrease with the extension of the continuous exhaust time, while the total exhaust time of the controllable train-tail device remains unchanged;the maximum coupler force of the combined train reduces by32.5% with the exhaust area increasing from 70% to 140%;when the lag time between the controllable train-tail device and the master locomotive is more than 1.5 s, the maximum coupler force of the train increases along with the time difference enlargement.

Aerodynamic optimization using passive control devices near the bogie cabin of high-speed trains

Bogies are responsible for a significant amount of aerodynamic resistance and noise,both of which negatively affect high-speed train performance and passenger comfort.In the present study,the passive control method is applied in designing the bogie cabins of a high-speed train to improve its aerodynamic characteristics.Two passive control measures are introduced,namely,adding a spoiler and creating diversion grooves near the bogie cabins.Furthermore,the aerodynamic and aeroacoustic characteristics of a high-speed train operating at 350 km/h under different control strategies are numerically investigated using the improved-delayed-detached-eddy simulation(IDDES)and the acoustic finite element method(FEM).The impacts of passive control devices on drag reduction,slipstream,and aerodynamic noise are presented and discussed.Numerical results reveal that the passive control devices have a major effect on the slipstream around the train.The amplitude of the fluctuating pressure is higher in the first half of the train than in the second half.The first bogie has the maximum amplitude of the acoustic pressure for both the train with and without passive devices.In the far field,the spoiler installation and placement of the diversion grooves in the front of the bogie cabin can significantly reduce aerodynamic drag and noise.Hence,as shown in this study,using passive control methods to improve the aerodynamic and aeroacoustic properties of high-speed trains can be a viable option.

Adaptive Sliding Mode Control Method for Onboard Supercapacitors System

Urban rail trains have undergone rapid development in recent years due to their punctuality,high capacity and energy efficiency.Urban trains require frequent start/stop operations and are,therefore,prone to high energy losses.As trains have high inertia,the energy that can be recovered from braking comes in short bursts of high power.To effectively recover such braking energy,an onboard supercapacitor system based on a radial basis function neural networkbased sliding mode control system is proposed,which provides robust adaptive performance.The supercapacitor energy storage system is connected to a bidirectional DC/DC converter to provide traction energy or absorb regenerative braking energy.In the Boost and Buck modes,the state-space averaging method is used to establish a model and perform exact linearization.An adaptive sliding mode controller is designed,and simulation results show that it can effectively solve the problems of low energy utilization and large voltage fluctuations in urban rail electricity grids,and maximise the recovery and utilization of regenerative braking energy.

运动员体能训练动作量化修正系统设计

跑步比赛中0.01s就能决定比赛的成败,为了确保教练和运动员能够获得更多的体能训练动作量化指标,设计运动员体能训练动作量化修正系统。基于Unity3D引擎设计控制模块、训练动作采集模块、训练动作模拟处理模块,利用灰色预测模型在提取体能训练动作特征的基础上识别训练动作,计算模拟动作系数,实现运动员体能训练动作量化修正。实验结果表明,该设计系统对跑步训练动作腿关节、踝关节角动作速率的识别准确性较高,体能训练动作数据管理效率较高,满足了节约运动员体能实际训练时间的需求。

多功能电气控制综合实训装置设计与研制

针对外购电气控制实验装置功能较为单一、扩展性欠缺、出现故障维护不便等问题,结合专业教学内容及实际需求,进行多功能电气控制综合实训装置的研发。该实训装置是基于模块化、可扩展、接近生产实际的继电控制及PLC的电气综合控制实训平台,以开放性和设计性实验为主,具有较强的综合性和应用性,用于电气控制与PLC为主的多门课程教学和实训教学。该实训装置提供多种控制对象或模型,既可进行继电接触式电气控制,又扩充了PLC控制、变频、HMI、通信及组态仿真等技术,有利于培养学生的综合实践技能及创新能力。

应答器传输系统测试用自适应定位装置研制

在测试中国列车运行控制系统(CTCS)应答器传输系统应答器、应答器传输模块及天线单元等产品过程中,需采用手动方式对齐产品电气中心,误差大、效率低、用时长。提出应答器传输系统测试用自适应定位装置要求,设计自适应定位装置,对硬件进行配置、选型,开发自适应定位装置应用软件,研制应答器传输系统测试用自适应定位装置,并应用该装置进行应答器传输系统测试定位。应用表明:采用自适应定位装置,能有效提高对齐准确度,缩短对齐时间,提高应答器传输系统产品的测试效率,减轻测试人员的工作量。

传热实训装置控制系统的设计与实现

针对高校实训要求,设计了符合工业生产实际的传热实训装置工艺流程,给出了电加热导热油炉、蒸汽发生器、套管式换热器等关键设备的控制策略。选用西门子S7-300PLC和MCGS组态软件实现了传热实训装置控制系统的设计。PLC程序采用模块化设计,同一个被控对象提供多种控制方案和功能模块供选择,部分控制回路采用串级控制等先进控制技术,保证了系统的精确稳定控制。MCGS组态界面操作方便,实训方案灵活多样,换热设备既可以串联运行,也可并联运行。该装置已经在高校投入使用,系统运行稳定、获得了较好的实训效果。

肢体康复训练器控制系统的研究

为了满足肢体康复需要,在分析肢体康复训练器机械结构和工作原理的基础上,对以可编程序逻辑控制器(PLC)为核心的控制系统进行研究。分析控制系统硬件各组成部分的功能及其特点,完成控制系统硬件整体方案设计,针对不同训练模式对软件进行开发。以触摸屏为上位机,负责人机交互、控制指令的发送和状态信息的显示;PLC为下位机,接受控制指令和采集传感器数据、控制电机的力矩和速度。患者可根据自己的具体情况选择适当的训练模式。实验表明,该控制系统性能稳定可靠,有较大的推广应用价值。

RH实训教学系统的设计与研制

针对高校实践要求,在实验室设计了符合生产实际的RH冷态实训装置。控制系统采用一体化控制柜。选用西门子S7-300PLC和紫金桥组态软件实现实训装置控制系统的设计。控制模式包括远程自动控制、远程手动控制和就地手动控制三种模式。通过研制与开发RH仿真实训模型,可实现教学内容形象化、时空化。该教学系统适用于课程教学实验、专业综合实验、创新研究以及毕业设计各个教学环节。

基于虚拟现实技术的机载火控系统模拟训练装置

对作战人员进行攻击不同目标的训练,传统的方法是靠实装进行,技术含量低,不能满足现代战争的需要。为提高部队的作战效能,采用虚拟现实(VR)技术,研制了机载火控系统模拟训练装置,为作战人员进行针对性的科学训练提供了方便。

某型发动机战斗与训练状态控制技术研究

简要介绍了对某型航空发动机在外场使用过程中,实施战斗与训练状态控制的方法及其相应的控制装置。加装该装置的目的是对发动机在平时训练时,实行降负荷使用,以提高飞行安全性,而在作战需要时,可恢复发动机原有状态,以发挥发动机最大潜能。控制装置由单片微机组成,具有自检和故障检查能力。通过试飞和试用证明,控制装置改装简单、工作可靠,取得了满意的效果。

基于卫星定位的列车完整性检查列尾设备性能测试方法

针对新型列控系统向着“车载中心化”的方式发展对列车完整性检查系统功能实现安全冗余的需求,在既有列尾设备检测风压提醒司机判定列车完整性功能的基础上,提出增加基于卫星的测速定位配合车载设备实施列车完整性检查,以保障列车完整性检查功能的可靠性和可用性。由于列尾设备安装条件限制,观测环境场景为典型的“半边天”场景,因此对列尾设备进行性能测试。基于浩吉重载铁路35.35 km的实测数据,采用电磁仿真软件进行列尾天线方向性设计,使用卫星导航模拟器构建仿真测试场景和设计测试序列,对列尾设备的定位性能进行了评估。评估结果表明,列尾设备在设计的天线方向图场景下观测参数和定位性能参数均符合典型的“半边天”场景特征;区间动态运行仿真结果,定位精度R95评估结果在BDS模式下为13.48 m,GPS模式下为9.12 m,BDS/GPS模式下为3.82 m,基于BDS/GPS的双模定位模式在车站停车、区间运行等场景下定位精度R95均优于4 m,表明采用双模定位方式能够满足列车完整性检查列尾设备定位精度小于5 m的要求。

电气控制与PLC技术半实物仿真实训装置构建

电气控制与PLC技术是一门实践性很强的专业课,为了满足其在不同应用环境下的实践需求,设计了一个基于组态软件的半实物仿真实训装置,利用该装置,可以通过直观、真实的界面,方便、安全地展现出PLC控制程序的执行效果,验证其正确性。最后,以自动化生产线中供料传输系统为例,阐述半实物仿真实训装置的构建与应用。

反应釜实训装置的设计与应用

在工艺生产中由于操作不当、控制系统不稳定等因素反应釜容易发生事故,学生也很难掌握实际的工艺反应过程。针对此现状,研制了一套反应釜实训装置,介绍了该装置的结构组成、控制系统的设计及装置的操作应用。结合PID算法和模糊控制理论设计了一种模糊PID控制器,利用MATLAB软件中的SIMULINK模块进行了仿真研究,并应用于反应釜实训装置的温度控制系统,该模糊PID控制器提高了反应釜温度控制系统的稳定性和动态响应速度。该装置在实践应用中展现了较强的实用性和安全性,为后续的生产工艺提供了良好的实验数据。

电控指夹式排种器实训装置的研制与应用

研制了电控指夹式排种器实训装置,该装置采用环形轨道代替播种路径,采用速度传感器获取播种单体行走的速度,通过行走控制器控制播种单体行走的速度。同时,还设计了一套自动收种器将电控指夹式排种器播下的种子自动收回种箱循环利用。此外,播种控制器可以调节播种的株距。该实训装置在本科生实验教学和开放式创新实验中应用后,深受学生欢迎,提高了学生的学习兴趣和实践动手能力。

一种基于PID电加热温度控制实训装置的开发设计

为丰富高职高专PLC实训课程内容,提高学生动手操作能力,介绍了一种基于PID控制原理,以S7-200PLC为控制核心的电加热温度自动控制实训装置。此装置通过温度传感器及变送器将采集的温度输入至PLC,经过与设定值比较和PID运算,采用数字输出方式控制SSR固态继电器输出,从而调节加热器加热,实现温度自动控制的目的。经实际测试,该装置运行稳定,操作方便,造价低廉,实训效果良好。

基于JX-300XP DCS控制的釜式反应器实训装置设计

针对石油化工专业群实验实训教学与科研的需要,提出一种基于JX-300XP DCS控制的釜式反应器实训装置基本结构,硬软件配置、功能以及应用系统的基本思路。实施结果表明,该系统提高了装置运行操作的安全级别,可完成石油化工专业群多个实训项目,使得实验实训更接近真实生产过程,为后续实验或工业生产设计提供可靠数据。

列车脱轨机理与脱轨分析理论研究

The major problems existing in the derailment studies are summarized according to analysis of the research status about train derailment in China and other countries of the world.(1) The current criteria for preventing derailment cannot assure that derailment will not occur.(2) It is not clear for train derailment mechanism.(3) There exist three fundamental problems in the calculation of train derailment as follows: ① The connecting condition of displacement between wheel and rail cannot be satisfied in establishment and solution of vibration equation group of train-track(bridge) time-variant system.② Only the lateral track irregularity is regarded as the exciting source of lateral vibration of train-track(bridge) time-variant system.The true exciting source,i.e.the wheel and rail contact status is neglected.③ The random lateral vibration of train-track (bridge) time-variant system is analyzed according to the random track irregularity and analysis theory of random vibration of time-invariant system.But the maximum responses of lateral vibration of train-track(bridge) time-variant system cannot be calculated,and furthermore train deraiment cannot be forecasted.The thinking and methods for solving these problems are also introduced.The train derailment mechanism,which is the result of losing stability in lateral vibration status of train-track(bridge) time-variant system,is proposed for the first time by analysis of characteristics of self-excitation of train vibration and losing stability in self-excitation vibration status of train derailment.So the key to analyzing train derailment is to analyze the stability of lateral vibration of train-track(bridge) time-variant system.The following conclusions are made by summarizing the existing analysis theory of stability of static and dynamic system.(1) Because of the characteristics of time-variant and self-excitation of train-track(bridge) system,the stability of lateral vibration of the system cannot directly be analyzed by the existing analysis theory of stability of static and dynamic system.(2) The common point of the existing analysis theory of stability of static and dynamic system is that the stability of static and dynamic system is evaluated by the comparison between the resisting force increment(or the increment of the work done by the resisting force) and the load increment(or the increment of the input energy) after the system status produces excursion.(3) Because of the characteristic of selfexcitation of lateral vibration of train-track(bridge) system,both of the load and resisting force of lateral vibration of the system is not clear.So the stability of lateral vibration status of the system must be evaluated by the increment criterion of the work done by the resisting force and the input energy,and not by the increment criterion of resisting force and load.The condition for the stability of the lateral vibration of train-track(bridge) system and no derailment of the train is put forward according to the concept that the Tacoma cable bridge will lose stability in self-excitation vibration status under the action of wind when the input energy accumulated in the course of vibration reaches the work done by the limited resisting force.That is,the work done by the limited resisting force is larger than the maximum input energy.A set of theory for random energy analysis of train derailment is proposed.And the main contents are as below.(1) Taking into account the connecting condition of wheel-rail displacement and the influence of the clearance between wheel flange and gauge line,the matrix equation of the spatial vibration of train-track (bridge) system is established to calculate the whole course of train derailment.(2) The geometric criterion of train derailment is established.(3) The method for calculating the whole course of train derailment is put forward.(4) The vibration responses of the whole course of train derailment are calculated.The relationship curve between the work done by the limited resisting force of the lateral vibration of the system and train speed is gained.And the increment expression of the work done by the limited resisting force of the lateral vibration of the system is also obtained.(5) The method for calculating the increment of the maximum input energy of the lateral vibration of the system is put forward.(6) The energy increment criteria for determining the stability status of the lateral vibration of the system and train derailment is established.The bogie frame hunting wave of a freight train on Beijing-Tonghua railway line is measured and the relationship curve between the standard deviation of the bogie frame hunting wave of the empty car and train speed is gained.The bogie frame hunting wave of a high-speed train on Qinhuangdao-Shenyang railway line for passenger traffic is also measured and the relationship curve between the standard deviation of the bogie frame hunting wave of the high speed train and train speed is obtained.A set of software TDAS v1.0 for analyzing train derailment with property right is independently developed based on the theory of random energy analysis for train derailment.According to the software,a grave derailment accident of number 33117 freight train on Changchun-tumen railway line is analyzed.Safety analyses are made of trains running on six bridges such as Nanjing Yangtz river bridge etc.with their lateral vibration amplitudes exceeding specifications.And derailment controlling of high speed trains running on supper major bridges such as Tianxinzhou combined highway and railway bridge,Hujiawan bridge and Hengyang-Xiangjiang bridge etc.on Wuhan-guangzhou railway line for passenger traffic is analyzed.All of the analysis results mentioned above have been applied by the corresponding railway departments.The preventive measures against derailment and methods for stipulating preventive standard against derailment are proposed.A derailment warning device is invented a national patent is also gained.To counter train derailment under normal condition of train operation,i.e.undefined derailment,the technical principle for a warning system against derailment is proposed.

基于GE PAC的过程控制实训装置的设计与开发

针对过程控制实训课程特点,选用GE智能平台PAC Systems RX3i和i FIX软件设计开发了一套工业过程控制实训装置,实现了温度、压力、流量、液位4个基本模拟量的实训和上位机监控等功能。试验结果表明系统运行稳定,操作简单,获得了较好的实训效果。

基于N:N网络的光机电一体化实训装置改造

为改善学校电气自动化专业实训教学条件,开发出符合学校教学实际的实训装置,形成集基础实验、验证实验、技能实操和设计创新为一体的实训系统。介绍了实训装置改造的基本思想、改造内容以及具体改造的实现过程。利用N:N网络改造光机电一体化实训装置,将机械手单元作为主站,上料单元、分拣单元作为两个从站。通过装置训练可使学生掌握PLC及其功能模块应用技术、电气控制技术、变频器技术、传感器技术、触摸屏及组态技术等工业控制技术。