Fabrication and measurement of the performance of a printed EMI shielding mesh filter on PET film

In this paper, Electromagnetic interference (EMI) shielding mesh filter films are fabricated using the screen printing method. An EMI shielding mesh filter requires fine line patterns under 30 μm, therefore, the screen masks with fine-line screen mesh, as well as suitable ink composed of fine metal particles are required. Moreover, because the printed EMI shielding filter has to be fabricated on a PET film, the ink should be sintered at a temperature below 150°C not to deform the film. For the purposes of this study, a screen mesh with a mask of 20 μm line, and ink made nano silver paste with a sintering temperature of 140°oC, which could guarantee fine-line patterning on the PET, were used. The ink had a viscosity of 90,000–12,000 cps and metal content of 85% in weight. The printed EMI shielding mesh had a line width of about 24 μm and a thickness of about 2.5 μm. The measured surface resistance was 0.5∼0.7 ω/□, offering good electrical performance as an EMI mesh. A simple measurement system was used to evaluate the electrical shielding performance of the printed EMI shielding mesh. A comparison of the printed EMI shielding mesh with pure film without mesh and copper sheet revealed that the printed EMI shielding mesh is indeed capable of providing good electrical performance.     

基于PROFINET现场总线的检测线设计

介绍了电图产品检测线的一种构成和工艺流程,电气控制系统的集成和相关控制技术.该检测线的数据服务器、工程师站、性能检测站、安规测试站、返修测试站、输送线控制站通过PROFINET组成开放式的以太网现场总线控制系统,可实现远程数据查询和故障诊断,并可同时对电器产品进行性能检测和安规测试.被测产品以条形码为识别码,所有的检测...     

基于传感器联合测量的车载POS精度检测系统设计

POS系统是移动测量系统的重要组成部分,其位置姿态精度一直受到广泛关注。结合全站仪、激光跟踪仪、GNSS授时装置等传感器,设计了动态精度检测系统,开展了POS系统动态精度检测方法研究。主要采用单次测量时间统计、平滑曲线拟合等方法探测检测系统的测量误差,并在误差剔除的基础上,结合ICP算法,利用跟踪仪高精度测量数据,对全站仪数据进行修正,提高检测系统整体测量精度。最后,在某实验区,进行车载POS系统动态跟踪实验,分别采用整体轨迹对比和实时点位对比方法进行POS系统事后处理精度检测和实时导航精度检测。实验结果表明:采用该种检测方法,动态检测系统能检测出POS实时和事后处理的动态定位精度。     

Microdevice for measuring friction and adhesion properties of sidewall contact interfaces of microelectromechanical systems

A microdevice was specifically designed to characterize the static and dynamic friction and adhesion characteristics of sidewall contact interfaces of microelectromechanical systems (MEMS). The microdevice was fabricated by surface micromachining and tested under conditions that accurately mimic those of typical MEMS contacts. The developed experimental scheme enables the direct measurement of the critical normal force at the instant of surface separation and the friction force at the onset of sliding. Additional capabilities include evaluation of the dynamic friction behavior, measurement of the electrical characteristics across the contact interface, and characterization of the tribological response under impact contact loading. The microdevice can operate over a wide range of normal forces and different environmental conditions. Because the design is independent of process environment, the microdevice can be used to study the effects of different surface treatments and variations in fabrication process steps on the tribological properties of MEMS contact interfaces. Characteristic results of static and dynamic friction behaviors, electrical contact resistance, and response to dynamic impact loading illustrate the experimental capabilities and versatility of the designed microdevice.     

一种基于神经网络的 THD 参数快速估计算法

模数转换器(ADC)测试主要包括静态参数和动态参数两个测试过程。随着性能的提升,ADC的测试复杂度和成本也急剧增加。替代测试,即通过分析两类参数间的关系来实现一个测试过程得到两类参数,已被证明是降低ADC测试复杂度和成本的主要方案之一。本文通过构建基于人工神经网络的参数预测模型来实现替代测试,模型以总谐波失真为预测目标,以静态性能参数为输入特征。针对高维的ADC非线性曲线,文章结合统计分析和主成分分析设计了专用的特征提取方法,在降低特征维度的同时尽可能地减少了信息损失。模型在测试集上的预测结果与参考值的均方误差和拟合优度分别达到了1.15 dB和0.6,显著优于相关对比模型。此外,在SHAP解释器的框架下分析了上述模型的预测目标和特征变量之间的依赖关系,并得到了有意义的结果。     

Experiences with the master axis method for measuring spindle error motions

In this paper, the master axis method of machine tool spindle measurement is described. This method allows spindle measurements to be carried out at speed and under load. For example, a radial load representing the cutting force in a turning operation can be conveniently applied during characterization of a lathe spindle. The synchronous and asynchronous error motions have been observed to vary in both magnitude and shape with changes in load. Test results from both static and dynamic loads during testing are shown to demonstrate the utility of the method.     

基于显式动力学的某齿轮轴冲击应力分析

在恒定转速下对某航空发动机附件机匣齿轮轴施加冲击扭矩的测试中出现齿轮根部折断的现象,为了分析其原因,利用有限元隐式和显式动力学方法,对齿轮轴在冲击扭矩下考虑旋转离心应力的静、动应力响应进行了计算分析,仿真结果与测试结果一致.根据分析结果对齿轮轴失效部位参数化建模,以齿轮轴质量最小为优化目标,利用APDL进行了失效部位的结构优化.优化结果表明,改进后的设计满足齿轮轴的功能要求,冲击载荷下产生的动应力水平与静态下冲击载荷产生的静应力比较,动应力有较大幅度的增加,在设计过程中应对齿轮轴在较短时间内的冲击载荷下产生的动应力加以考虑,以保证齿轮轴的强度有足够的安全裕度.     

动态接触电阻测试系统的研究

对于触点电接触状态的好坏,一般用静态下接触电阻的大小来衡量,而触点的动态接触电阻研究尚未深入开展。本文针对小容量触点的接触可靠性进行了阐述,详细介绍了一种新研制的小容量触点的动态接触电阻测试系统。     

Note: Mechanical and electrical characterization of nanowires in scanning electron microscope

This note presents two experimental techniques for mechanical and electrical characterization of individual nanowires inside a scanning electron microscope (SEM). Tensile testing is realized by transferring a nanowire to a microelectromechanical systems device that stretches the nanowire and measures the elongations and tensile forces. The device consists of an electrostatic actuator and two capacitive sensors, capable of acquiring all measurement data (force and displacement) electronically without relying on electron microscopy imaging. For electrical characterization, four-point probe measurement of individual nanowires is performed automatically by controlling four nanomanipulators with SEM visual feedback. A feedforward controller is incorporated into the control system to improve the response time. This work represents advances in nanomaterial testing and automated nanomanipulation.     

Dynamic evaluation of spatial CNC contouring accuracy

An instrument capable of measuring arbitrary, dynamic CNC tool paths through three-dimensional space with micrometer-level accuracy is developed and tested. The instrument uses three Laser Ball Bars simultaneously (i.e., simultaneous trilateration) to allow for dynamic path measurements. The design of the instrument is described. The performance is verified by static repeatability testing, comparison with an independent measurement system, and comparison with the dimensions of machined parts. The instrument is demonstrated to be capable of measurement of arbitrary three dimensional tool paths with near micron level accuracy.     

先导式阀门先导结构的研究进展

为充分认识先导式阀门的优势,有效提升先导式阀门的使用性能,从先导结构的驱动部件、弹簧组件、阀芯和阻尼孔四个方面,整理了先导式阀门的最新发展;从压力控制、流量控制和方向控制三个方面介绍了先导结构控制先导式阀门所实现的不同功能;从静态特性和动态特性两个角度分析了不同先导结构对先导式阀门性能的影响。结果表明:先导式阀门的阀芯形式、阻尼孔位置对阀门性能影响较大;对于流量控制和方向控制的控制策略还需进一步创新;先导式阀门的动态、静态特性指标之间存在一些不统一的地方。未来,新型特种先导式阀门开发、先导结构参数对阀门动静态特性影响的量化分析将是重要的研究方向。     

微机电系统静动态测试技术研究

在中国国家863高技术发展计划MEMS重大专项课题《MEMS动态特性频闪干涉视觉三维测量技术及系统》资助下，研发微机电系统(Micro Electro Mechanical System , MEMS)动态特性三维测量技术与系统。对已有的微几何量、微材料力学性能和MEMS动态参数测试方法进行研讨。 几何尺寸和表面形貌轮廓的测量是MEMS测量的基础。二维微几何量检测采用普通光学显微镜和扫描电子显微镜。表面形貌测量大致可分为接触式测量和非接触式测量，机械触针式轮廓仪是典型的接触式测量仪器，非接触式测量大多采用光学技术，主要有光针式轮廓仪，采用光切、干涉、投影光栅和微视觉等测量方法。     

Electrical energy metering: Some challenges of the European Directive on Measuring Instruments (MID)

The introduction of static electric energy meter together with voltage and current distortions in the electric networks are revolutionizing the measurement of the electrical energy. Several questions and studies are proposed in the scientific literature concerning with metrological and reliability aspects of the actual electrical energy measurement. The European Directive on Measuring Instruments (MID) represents a different spin on setting the performance and safety requirements for those meters. The International Organization of Legal Metrology (OIML) has published the document D11 discussing recommendations for legislation to meet the MID. An OIML technical committee is drafting the recommendation (IR46) that would give regulatory bodies an easily-adoptable set of requirements and tests to meet the requirements of the MID. With the introduction of the MID directive, the actual discussion involves aspects as the metrological characterization of the meters. The paper proposes an analysis of the test settings imposed by the actual MID-harmonized standards, regarding the electric energy metering. The aim is to check the presence of degree of freedom in the test settings that could compromise both result reliability and the compliance/non-compliance of a given apparatus.     

High-speed analog fiber-optic link for electromagnetic interference suppression in infrared power measurement

Electromagnetic interference (EMI) is a common problem in a high-power pulsed infrared laser measurement. In order to eliminate susceptibility to radiated EMI, we developed, tested and implemented an infrared power measurement system using a high-speed analog fiber-optic link. Key components are commercially available parts designed for high-speed digital data transmission, but can be operated in analog mode. We successfully utilized the system for time-resolved measurements of high-power transversely-excited atmospheric-pressure CO(2) lasers in amplifier and oscillator configurations. This paper presents experimental setup, testing results, and the details of the laser power measurements results.     

应变片用于斯特林发动机活塞位移的动态测量

结合自由活塞斯特林发动机的结构特点,提出了采用应变片响应板弹簧变形来动态测量活塞位移的方法。根据应变片的电阻应变效应与应变仪的电桥原理,建立了一套应变片测量位移的动态标定试验系统,将动态标定数据与静态标定数据进行了比较分析。试验结果表明,应变片测量位移的方法存在一定的正反向、动静态差异,应变片的粘贴位置也会直接影响测量准确性。基于应变片传感器体积小,与板弹簧结合粘贴无需占用专门的空间,通过标定校准和合理的安装位置,仍然是一种较好的位移测量传感器。     

双自由度电磁阀测试平台研究

为了对行程0～4 mm、双向输出力各0～10 N的双自由度电磁阀的动态及静态特性进行准确测试,建立了相对应的新型电磁阀动静态特性测试平台。利用该平台,在对双自由度电磁阀内外推杆同时输入激励时,可以准确地测量双自由度电磁阀的内推杆与外推杆的动、静态特性,并通过LabVIEW对数据进行精准大量采集。利用Ansoft仿真软件对电磁阀的静态特性进行仿真,利用测试平台对电磁阀开启与关闭时的静态特性进行测量,对仿真数据与静态实验数据进行比对,并测量电磁阀动态特性。结果证明双自由度电磁阀测试平台工作精确并稳定。     

抓斗卸船机钢结构应力谱统计方法

以某码头1 800 t/h牵引式抓斗卸船机为研究对象,首先通过有限元分析软件Ansys对卸船机进行建模计算,确定结构的静载应力以及动载应力测点;然后模拟其真实卸船作业的典型工况,采用应变电测法对相关测点的动载应力进行实时数据采集;最后根据抓斗船型及抓取量对应力谱的影响,对卸船机钢结构应力数据进行统计分析,得到钢结构测点对于各种船型整个工作循环的应力谱,结合各船型到港次数,进而可以推算出卸船机钢结构测点全年的应力谱,为疲劳寿命评估打下了基础。     

基于自动测试系统的ADC测试开发

A／D转换器（ADc）是混合信号系统中的重要模块，是电子器件中的关键器件。随着器件时钟频率的不断提高，如何高效、准确地测试ADc的动态参数和静态参数是当今ADc测试研究的重点。本文阐述了ADC的静态和动态参数测试，并在自动测试系统的ADC测试过程中，深入分析了ADC测试环境的配置，从而实现了一种低成本、高可靠性的ADC计算机辅助测试方法，并在BC3192VS0测试系统上得到了验证。     

基于SVM的电梯制动器静态制动力矩估算方法研究

针对电梯制动器静态制动力矩估算问题,对电梯制动器的动态制动性能与静态制动性能分别进行了研究,利用电梯制动器试验台测试制动器的制动性能,根据实验测试结果提出了一种基于支持向量机的电梯制动器静态制动力矩估算方法,将利用制动器动态制动性能实验得到的制动初始速度与制动过程的平均制动力矩作为估算算法训练数据的输入值,将相同制动器对应的静态制动力矩作为估算算法训练数据的输出值,经过支持向量机算法训练得到估算模型,采用网格搜索法进一步优化估算模型。最后,通过制动实验进一步采集制动性能数据作为验证数据。实验结果显示,电梯制动器的动态制动性能与制动初始速度有关。交叉验证的结果表明,基于SVM的电梯制动器静态制动力矩估算方法能够便捷准确地根据电梯制动器的动态数据估算出静态制动性能。     

滚珠丝杠副综合性能动态测量系统设计

介绍了滚珠丝杠副综合性能动态测试系统设计,根据测试系统技术要求,确定了测试系统总体方案,对系统的机械结构及电气组成进行了设计,确定了试验条件及测量方法,开发了系统测试软件。构建的测试系统可以动态实时测量滚珠丝杠副在四种安装方式下振动、噪声、温升、极限转速等性能。通过试验及试验数据采集与分析,根据HJS056动态测量的滚珠丝杠副噪声、振动、温升、极限转速等性能测试结果,取得了四种安装方式下滚珠丝杠副性能试验结论,为滚珠丝杠副的优化设计提供实验数据。