Inertia Matching During Dynamic Simulation of Vehicle Drive System on Test Bench

Framework and basic parameters of a test bench for motor drive system of electric vehicle (EV) are illuminated. Two kinds of electric drive models, one was for the electric vehicle drived on real road, the other was for that on test bench, are put forward. Then, dynamic analysis of these models is made in detail. Inertia matching method of the test bench is researched and some useful formulas and graphs are brought forward. The experiment of an electric bus is introduced in order to explain the usage of this inertia matching method.

A versatile test bench for photomultiplier tube characterization and its application in the DAMPE-PSD

Performance characterization for massive photomultiplier tubes(PMTs) is a frequently encountered procedure in large nuclear and particle experiments.To facilitate this work,a dedicated test bench system has been developed at the Institute of Modern Physics,Chinese Academy of Sciences.The two-dimensional photocathode position scanning capability is an intrinsic function of the test bench,and up to 25 PMTs,with the diameter smaller than 2",can be tested simultaneously.The parameters of the light source pulses can be adjusted in a wide range,thus making it suitable for various characteristics measurements.The test bench system is highly automated with all the controlling operations integrated into a single software.Additionally,the hardware platform is extensible which allows complex testing schemes,and the modularity in the software design makes the migration from one testing configuration to another light-weight and efficient.All these features make the test bench versatile and reusable in different experiments.It has been first used in the construction of the Plastic Scintillator Detector(PSD) of DArk Matter Particle Explorer(DAMPE),and a total of 570 Hamamatsu R4443 tubes were tested successfully.The performance was verified and the testing results are also reported in this article.

Electronic Unit Pump Test Bench Development and Pump Properties Research

A unit pump test bench is developed on an in-line pump test platform. The bench is composed of pump adapting assembly, fuel supply subsystem, lubricating subsystem and a control unit. A crank angle domain injection control method is given out and the control accuracy can be 0.1° crank degree. The bench can test both mechanical unit pump and electronic unit pump. A test model-PLD12 electronic unit pump is tested. Full pump delivery map and some influence factors test is done. Experimental results show that the injection quantity is linear with the delivery angle. The quantity change rate is 15% when fuel temperature increases 30 ℃. The delivery quantity per cycle increases 30 mg at 28 V drive voltage. The average delivery difference for two same type pumps is 5 %. Test results show that the bench can be used for unit pump verification.

Study of the Judder Characteristics of Friction Material for an Automobile Clutch and Test Verification

The friction judder characteristics during clutch engagement have a significant influence on the NVH of a driveline.In this research,the judder characteristics of automobile clutch friction materials and experimental verification are studied.First,considering the stick-slip phenomenon in the clutch engagement process,a detailed 9-degrees-of-freedom(DOF)model including the body,each cylinder of the engine,clutch and friction lining,torsional damper,transmission and other driveline parts is established,and the calculation formula of friction torque in the clutch engagement process is determined.Second,the influence of the friction gradient characteristics on the amplification or attenuation of the automobile friction judder is analyzed,and the corresponding stability analysis and the numerical simulation of different friction gradient values are carried out with MATLAB/Simulink software.Finally,judder bench test equipment and a corresponding damping test program are developed,and the relationship between the friction coefficient gradient characteristics and the system damping is analyzed.After a large number of tests,the evaluation basis of the test is determined.The research results show that the friction lining with negative gradient characteristics of the friction coefficient will have a judder signal.When the friction gradient value is less than-0.005 s/m,the judder signal of the measured clutch cannot be completely attenuated,and the judder phenomenon occurs.When the friction gradient is greater than-0.005 s/m,the judder signal can be significantly suppressed and the system connection tends to be stable.

俯仰式播种单体仿形性能检测试验台设计与试验

为解决播种单体仿形机构性能难以检测的问题,设计了俯仰式播种单体仿形性能检测试验台。阐述了试验台组成结构与工作原理,对其高速传动系统、液压升降系统、监控系统以及关键部件参数进行设计。应用ANSYS软件对台架整体和关键部件进行静力学分析和模态分析,验证结构设计的合理性。为检验俯仰式播种单体仿形性能检测试验台的实际检测效果,以德邦大为1205型牵引式免耕精量播种机播种单体为研究对象,先以液压杆伸出量与传送带速度为试验因素,以监控系统误差为评价指标进行试验。试验得出,在液压杆伸出量为0~200 mm范围内,监控系统角度传感器最大误差为0.69 mm;在传送带速度8~19 km/范围内,光电编码器最大误差为0.18 km/h。确认监控系统准确性后,再以单体速度为试验因素,采集速度8、10、12 km/h下地块的起伏数据为目标曲线,以地形起伏模拟曲线的绝对误差平均值为指标进行单因素试验,试验得出,所设计的试验台可有效模拟田间地面的起伏频率与起伏量,绝对误差平均值为1.86 mm,满足播种单体仿形性能检测需求。

挖掘机多路阀试验与仿真分析

首先,设计了挖掘机多路阀台架试验方案,多路阀试验台架的主要单元组成包括动力源单元、模拟负载单元、控制系统单元等,本实验台架可对多路阀的流量特性、压力损失特性、主安全阀的二次升压特性、保持阀的启闭特性、逻辑阀的流量分配特性、再生特性等进行试验。然后,试验了多路阀的左直线行走滑阀在空载时的流量特性。最后,对比分析了多路阀左直线行走滑阀的试验数据和仿真数据,得出以下结论:(1)在台架试验中,传感器的选型、布置位置都对试验结果有影响;(2)全方位地对比了左直线行走滑阀的试验数据和仿真数据,其模型精度在90%以上。高精度的仿真模型可进一步优化分析左直线行走滑阀的性能。

Torque effect on vibration behavior of high-speed train gearbox under internal and external excitations

The high-speed train transmission system,experiencing both the internal excitation originating from gear meshing and the external excitation originating from the wheel-rail interaction,exhibits complex dynamic behavior in the actual service environment.This paper focuses on the gearbox in the high-speed train to carry out the bench test,in which various operat-ing conditions(torques and rotation speeds)were set up and the excitation condition covering both internal and external was created.Acceleration responses on multiple positions of the gearbox were acquired in the test and the vibration behavior of the gearbox was studied.Meanwhile,a stochastic excitation modal test was also carried out on the test bench under different torques,and the modal parameter of the gearbox was identified.Finally,the sweep frequency response of the gearbox under gear meshing excitation was analyzed through dynamic modeling.The results showed that the torque has an attenuating effect on the amplitude of gear meshing frequency on the gearbox,and the effect of external excitation on the gearbox vibration cannot be ignored,especially under the rated operating condition.It was also found that the torque affects the modal param-eter of the gearbox significantly.The torque has a great effect on both the gear meshing stiffness and the bearing stiffness in the transmission system,which is the inherent reason for the changed modal characteristics observed in the modal test and affects the vibration behavior of the gearbox consequently.

In vitro bench testing using patient-specific 3D models for percutaneous pulmonary valve implantation with Venus P-valve

Background:Due to the wide variety of morphology,size,and dynamics,selecting an optimal valve size and location poses great difficulty in percutaneous pulmonary valve implantation(PPVI).This study aimed to report our experience with in vitro bench testing using patient-specific three-dimensional(3D)-printed models for planning PPVI with the Venus P-valve.Methods:Patient-specific 3D soft models were generated using PolyJet printing with a compliant synthetic material in 15 patients scheduled to undergo PPVI between July 2018 and July 2020 in Central China Fuwai Hospital of Zhengzhou University.Results:3D model bench testing altered treatment strategy in all patients(100%).One patient was referred for surgery because testing revealed that even the largest Venus P-valve would not anchor properly.In the remaining 14 patients,valve size and/or implantation location was altered to avoid valve migration and/or compression coronary artery.In four patients,it was decided to change the point anchoring because of inverted cone-shaped right ventricular outflow tract(RVOT)(n=2)or risk of compression coronary artery(n=2).Concerning sizing,we found that an oversize of 2-5 mm suffices.Anchoring of the valve was dictated by the flaring of the in-and outflow portion in the pulmonary artery.PPVI was successful in all 14 patients(absence of valve migration,no coronary compression,and none-to-mild residual pulmonary regurgitation[PR]).The diameter of the Venus P-valve in the 3D simulation group was significantly smaller than that of the conventional planning group(36[2]vs.32[4],Z=-3.77,P<0.001).Conclusions:In vitro testing indicated no need to oversize the Venus P-valve to the degree recommended by the balloon-sizing technique,as 2-5 mm sufficed.

船舶柴油机余热回收试验台测控系统设计及试验研究

为提高船舶柴油机余热回收试验台的自动化程度,开发了基于STM32和LabVIEW的船舶柴油机余热回收试验台测控系统。系统能够同步测量换热器进出口冷却水的温度和流量,通过改进PI算法自动控制换热器出口的冷却水温度,并在上位机界面上动态显示测量数据和控制效果,具备数据采集、远程控制、数据保存和故障报警等模块化功能。测试结果表明,数据采样周期小于500ms,冷却水流量的调节精度达0.1m^(3)/h,在换热器出口冷却水温度设定值为18.8℃时超调量为0.5%。

变量喷药控制系统测试试验台设计与实验

基于目前变量喷药控制系统测试装置性能单一,室内开展喷雾试验无法对雾滴进行回收导致用电安全等问题,设计一款变量喷药控制系统测试试验台。对试验台进行相关性能测试,试验台压力测量精度97.53%;建立基于管道压力、电磁阀响应频率和不同脉宽调制三因素单喷头流量关系模型,根据管路实时压力变化进行喷头流量调控;试验台雾滴回收率达90%。该试验台对开展室内变量喷药控制系统测试,防止雾滴飘移,提高室内试验安全性具有重要意义。

制种油菜杂株铲齿式拔除试验台设计与试验

针对目前人工拔除油菜杂株耗时、费力的情况,设计了一种铲齿式末端执行器,并搭建了试验台,可实现机械化杂株拔除作业。基于PLC的试验台控制系统包含硬件与软件两部分,可通过触摸屏设置作业参数、显示与记录数据,实现自动化杂株拔除作业。试验表明:试验台配合铲齿式末端执行器能够顺利进行制种油菜杂株机械化、自动化拔除作业,运行可靠且满足制种油菜田农艺要求,控制系统具有操作简单、效率高、使用成本低等优点。

基于LabVIEW的高速列车变轨轮对性能试验测试系统研究

变轨距轮对技术是解决铁道车辆在轨距不同区间直通运行的一种行之有效的方法,根据某主机厂设计的新型变轨距轮对的变轨原理和技术参数,研制了变轨距轮对综合性能试验台,模拟变轨距轮对解锁/锁紧、变轨、跑合等功能。变轨距轮对的性能直接影响到变轨距转向架的性能,对列车的运行安全起到至关重要的作用。以变轨距轮对为研究对象,针对轮对在变轨过程中的运动状态及性能,进行了测试方法与试验研究。利用上位机软件LabVIEW进行编程控制,通过采集的数据进行分析处理,实时监测轮对运行的状态。试验结果表明,系统能够完成轮对的型式试验性能测试,并且可以有效地监控设备运行状态并能进行故障预警和处理。研究可为变轨距转向架和变轨列车的运行提供技术支持,具有一定的工程应用价值。

应用AMESim双转向器全液压转向系统特性分析

为全液压转向系统设置双转向器可以解决大排量需求的问题,但此种布置会影响系统的动态响应特性,因此分析系统的可行性。根据某自卸车全液压转向系统的结构特点,对单转向器系统的关键参数进行分析和设计,获取各参数的数值;根据车辆转向参数的需求,对转向系统的压力损失和温升进行校核,以验证系统可否满足需求;根据前述分析,采用AMESim搭建分析模型,通过转角输入验证模型准确性,并验证负载、输入变化对系统特性的影响;基于转向系统试验台,通过输出特性分析,对前述设计和分析模型进行验证。结果可知:双转向器系统压力损失满足要求,最高温升控制在56.8℃,控制在系统要求的范围内;影响双转向器系统输出特性和油液流量的因素主要是方向盘转速和系统负载,其他因素基本无影响,仅对系统的响应时间产生影响;试验测试平台获取的角速度阶跃输入下的,转向器输出口压力、流量放大器输出口流量与仿真分析结果误差控制在5%以内,表明分析模型和结果的可靠性,为此类分析设计提供参考。

High RF power tests of the first 1.3 GHz fundamental power coupler prototypes for the SHINE project

The Shanghai High Repetition Rate XFEL and Extreme Light Facility(SHINE)project will use 6001.3 GHz fundamental power couplers,which are modified based on TTF-Ⅲ power couplers,for continuous-wave operation with input power up to approximately 7 kW.The first batch of 20 sets of 1.3 GHz coupler prototypes was fabricated from three domestic manufacturers for the SHINE project.To better characterize the radio frequency conditioning phenomena for validating the performance of power couplers,a room temperature test stand was designed,constructed,and commissioned for the SHINE 1.3 GHz power couplers.In addition,a horizontal test cryostat was built to test the 1.3 GHz superconducting cavities,fundamental power couplers,tuners,and other components as a set.The results of these tests indicate that the 1.3 GHz couplers are capable of handling up to 14 kW continuous waves.Herein,the main aspects of the radio frequency design and construction of the test stand,along with the test results of the high-power conditioning of the 1.3 GHz couplers,are described.

配电系统中全绝缘一体化智能台架技术研究及应用

为解决当前配电网台架普遍存在的人员易触电、因飘挂物短路接地、占地面积大、施工周期长等问题,对全绝缘一体化智能台架在配网建设中的实际应用进行了探讨。与传统台架相比较,全绝缘一体化智能台架将高压开关、变压器、低压出线融合为一体化结构,采用模块化装配,有效减少了设备体积,提高了用地效率,缩短了现场施工周期,极大降低了周围居民触电等安全隐患。结果表明,全绝缘一体化智能台架在配电网建设中具有较高的推广应用价值。

基于AMESim的矿用制动实验台液压系统设计与仿真研究

液压系统是矿用制动装置液惯量式实验台的核心组成部分,对实验台液压系统进行设计,通过理论计算选择关键元件,利用AMESim仿真软件搭建仿真模型及进行仿真分析,验证实验台液压系统的液压值、主轴转速以及扭矩设计的合理性。将仿真分析结果和实验结果进行比较,以此来验证理论计算的选型合理性。结果表明:仿真所得结果与实验结果基本相符,因此验证了实验台液压系统设计的准确性。

Design and Experiment of Electronic-hydraulic Loading Test-bed Based on Tractor's Hydraulic Steering By-wire

An Electro-hydraulic loading system is designed based on a test-bed of tractor's hydraulic steering by-wire. To simulate the steering resistance driving tractor in many kinds of soils and roads,the loading force is controlled to make proportional and continuous variable by an electro-hydraulic proportional relief valve. A steering resistance loading test-bed is built to test three kinds of steering resistance including constant,step and sine style. Tire lateral resistance is also tested under different steering conditions. The result shows that the electro-hydraulic loading system has high stability and following performance. Besides,the system's steady state error is lower than 3. 1%,and it meets the test requirement of tractor's hydraulic steering by-wire.

基于LabVIEW的测控系统设计

根据行星滚柱丝杠寿命试验要求,设计了一种行星滚柱丝杠寿命试验台测控系统。首先介绍了行星滚柱丝杠寿命试验台的结构组成,通过对滚柱丝杠寿命试验的原理与所需功能的研究分析,设计了试验台的加载控制系统、伺服驱动系统以及数据采集系统,最后对寿命试验所得到的数据曲线进行了分析。试验结果表明,该测控系统可以满足试验台对滚柱丝杠寿命测试的要求,试验台加载力最高可达150 kN,加载精度可保持在±10%F.S,同时可以对寿命试验中丝杠的温升、振动、噪声等性能参数进行实时采集与保存,为行星滚柱丝杠寿命的进一步研究提供数据支持。

基于负载补偿的功率分流混合动力系统模式切换性能测试方法

由于功率分流混合动力系统性能测试台架与实际车辆的动力学特性存在差异,导致测试台架难以精确模拟实车的行驶负载特性,使得功率分流混合动力系统模式切换性能测试的准确度不高。为此,本文提出一种基于负载动态补偿的功率分流混合动力系统模式切换性能台架测试方法。首先,建立了考虑实际车辆道路负载、模拟发动机、功率分流混合动力专用变速器(dedicated hybrid transmission,DHT)和测试台架传动系统的台架系统动力学模型;其次,针对纯电动至功率分流混合动力模式切换过程,对比分析了动力源的动态响应和台架系统模型的加载特性;然后,设计了基于转速闭环跟踪的转速前馈校正补偿器以提高负载模拟转速控制的抗干扰能力,并结合转矩前馈校正补偿器降低加载转矩的动态误差。最后,离线仿真和硬件在环台架试验结果表明:基于台架系统模型开发的负载动态补偿算法可提高测试台架加载精度32.67%以上,保证了功率分流混合动力系统模式切换性能测试的准确性。

盾构机主轴承试验台测控系统设计与应用

盾构法是地下交通施工的一项关键技术,在隧道施工建设上得到广泛应用.基于LabVIEW平台,设计盾构机缩比主轴承试验台测控系统.该系统既能够实现对试验轴承施加轴向和径向载荷,以及对试验轴承的振动数据和温度数据的实时采集、显示、处理、记录及保存,又能够将采集到的振动数据对试验轴承进行包含峰值、脉冲、裕度、波形和峭度等指标在内的时域分析和包含频谱、包络谱和倒频谱在内的频域分析.实验结果表明该系统设计合理、运行可靠、结果分析准确,能够满足试验需求,具有一定的工程应用价值.