基于希尔伯特变换的信号解调算法及其在飞机供电特性参数测试系统中的应用

电压调制幅度、频率调制幅度和畸变频谱是对飞机机载电源系统供电特性参数进行测试时与信号调制相关的重要参数。为了更好地测试这些参数,提出了一种基于希尔伯特变换原理的数字解调算法,可以将采集的幅度或频率调制信号进行解调分析;同时,构建了一套飞机供电特性参数测试系统,将解调程序与硬件设备结合,通过程序控制数据采集卡对机载电源信号采样与解调分析;设计了实验对波形发生器产生的调制信号进行采样与解调,验证了该系统具有良好的效果,可以应用于飞机供电特性参数的测试中。     

Dynamic Testing of Waveform Recorders

Four waveform recorder tests are presented that characterize dynamic performance using sine-wave sources. Each test illuminates different aspects of dynamic performance, and in some cases indicate the specific errors limiting performance. Pitfalls in using the tests are also examined.     

虚拟仪器在声波激发的地表振动检测系统中的应用

设计一个声波激发的地表振动检测系统,用基于Labview的软件平台实现数据的采集与处理。用扬声器发出扫频的正弦声波激励地表产生地表振动,并用地震检波器接收地表振动速度信号,通过NI 5112数字化仪传送到计算机,在Labview环境下进行滤波、频谱分析、波形显示与数据存储等处理。实验结果显示,该系统能有效完成测量任务,可用于声-地震耦合现象的进一步研究。     

基于高速A／D卡的全波形采集超声自动检测系统

设计了一种全波形采集超声自动检测系统,实现了A,B,C 3种扫描方式且具有记录被检材料上所有检测点超声A扫描波形的功能,支持材料超声检测、评价技术研究.该系统由高速A/D卡、超声检测仪、自动扫描器、运动控制系统和CSCAN软件等组成,作为核心部件的高速A/D卡选用PCI-9820型,负责从超声检测仪采集A扫描波形信号.自动扫描过程中,A/D卡与超声检测仪、运动控制系统之间通过硬件信号实现同步,使A扫描波形数据的采集与被检材料上声传播的渡越时间、预定测量点位置相对应,采集得到的A扫描波形数据通过A/D卡的板载SDRAM及DMA功能异步传输至计算机内存,并由CSCAN软件进一步实现数据压缩、滤波、存储以及不同方式成像等处理.测试结果证明,该系统运行速度快,成像精度高且性能稳定. 更多还原     

Improved Techniques for the Measurement of High-Voltage Impulses Using the Electrooptic Kerr Effect

The purpose of this paper is to present two methods of accumulating, analyzing, and presenting in real time the data generated by a Kerr system in response to a high-voltage impulse. These methods provide immediate information concerning selected electrical parameters in a form which is easily interpretable by most personnel. The first method uses an electronic counter to determine the number of optical transmittance maxima, i.e., light pulses, duritg the high-voltage impulse. From this count, the peak value of impulse can be calculated. The second method, which can be more accurate and does provide information concerning waveshape, uses a digital recorder to store the output waveform from the Kerr system. A computer is then used to reconstruct the voltage impulse and to determine such parameters as the peak value and risetime of the impulse.     

瞬态波形记录仪器计量标准的建立

叙述了瞬态记录仪器计量标准建立中的几个问题 ,包括校准系统的构成、校准项目、校准方法、校准设备的选择 ,以及影响有关指标校准不确定度的几个因素     

A fast-pulse oscilloscope calibration system

A system is described for calibrating high-bandwidth oscilloscopes using pulse signals. The fast-pulse oscilloscope calibration system (FPOCS) is to be used to determine the step response parameters for digitizing oscilloscopes having bandwidths of ~20 GHz. The system can provide measurement traceability to standards maintained at the U.S. National Institute of Standards and Technology (NIST). It comprises fast electrical step generation hardware, a personal computer (PC) and software, and a reference waveform, i.e., a data file containing an estimate of the step generator output signal. The reference waveform is produced by prior measurement by NIST of the step generator output signal (calibration step signal). When the FPOCS is in use, the calibration step signal is applied to the device under test, which is an oscilloscope sampling channel. The measured step waveform is corrected for timebase errors, then the reference waveform is deconvolved from it. The results are impulse, step, and frequency response estimates, and their associated parameters (e.g., transition duration, transition amplitude, -3 dB bandwidth) and uncertainties. The system and its components are described, and preliminary test results are presented     

A High-Sensitivity Narrow-Band Time-Domain Reflectometer

Time-domain reflectometer (TDR) techniques have been used to test transmission line systems for over fifteen years. The technique described in this paper is an extension to present-day techniques and is designed particularly to detect small changes in the reflection coefficient of distributed systems versus time. The instrument uses some of the techniques of narrow-band TDR to provide a waveform, related to the distributed reflection coefficient of the system under test, to a small computer. The computer can then perform any of a number of manipulations to the waveform, depending on the wishes of the operator. One particular program produces a waveform profile on a storage oscilloscope which displays small changes in the distributed reflection coefficient with time. This capability of being able to display very small changes in reflection coefficients has resulted in the development of an obstacle detection scheme using so called "leaky" coaxial cable to detect objects at some distance from the cable.     

电动工具自动检测系统

介绍了计算机在电动工具检测线中的应用,阐述了系统的工作原理及工作过程,重点分析了计算机系统的软、硬件设计.在电动工具的检测中引入计算机,可将以人工为主的、误差较大的检测方式变为精确的自动检测.该系统已成功地应用于电动工具检测线上.该系统性能稳定可靠,检测精度高,速度快,自动化程度高.该技术还可应用于许多机电产品的自动检测,具有推广实用价值.     

A Microcomputer-Based System for Area Measurement

An electronic system developed for area measurement is described. A standard X-Y recorder specially adopted with a light pen was made to scan the area under test and give a TTL logic signal that changes state whenever the area circumference is crossed. From such information the microcomputer is programmed to calculate the area using Simpson's rule and display the result on a seven-segment display. Sources of error in measurement and its nature are investigated. Modifications in the basic system to reduce the error are included. The designed system can also be used for determining the perimeter and locating the centroid of an object.     

一种新的低压无功功率补偿装置放电试验测试仪的研发

随着电气产品的发展,低压无功功率补偿装置标准对装置内电容器放电试验的检测要求越来越高,各检测机构必须配以更先进的检验设备才能为电器企业提供更好的检测服务。本文通过引入虚拟仪器技术,将传感器、电子元件、采集卡、计算机等结合起来设计一套便携式低压无功功率补偿装置放电试验测试仪,实现数据采集、波形分析、参数计算、报表自动生成等功能,满足标准中的试验要求,提高工作效率和检测精度。     

多点激励振动试验控制技术进展

多点激励振动试验由于能更加真实地模拟实际振动环境而被越来越多的人所重视,成为振动环境试验发展的趋势.阐述了多点激励振动试验系统基本控制原理,并对时域波形复现的关键技术迭代算法和驱动信号重叠连接,以及频谱再现的关键技术反馈修止算法和时域随机化技术进行了介绍.最后对多点激励振动试验控制技术进行总结与展望.     

一个高温持久/蠕变测控温及试验管理系统

介绍了采用测控分开形式对近百台五六十年代制造的高温持久/蠕变试验机进行测控温系统改造的工作.改造后的控温系统创造了不同热电偶数量(测控温共偶,1～3支)都可实现对试样温度和梯度的稳定控制,系统具有较强抗外界干扰能力,而且控温过程中对电网无干扰.测量系统测量误差≤±0.1%FS.测控温系统采取单炉闭环控制、30台集中巡回...     

深孔内含水炸药爆速和相对爆压的现场测试研究

长沙矿冶研究院和武钢大冶铁矿、本钢南芬露天铁矿合作进行了深孔内含水炸药爆速和相对爆压的测试研究。测试结果表明,运用改进的探针法—数字爆速仪和电气石压电晶体传感器－ 瞬态波形记录仪两种方法,可为改善破碎质量和大规模干扰降震提供可靠的数据     

圆光栅检测仪的研制

介绍了一种高精度、精密、自动化、动态测量的光栅检测仪,测量光栅盘的扩展不确定度为０．０８”。该仪器采用了高回转精度的空气静压轴承及多头均化技术,减小了参考盘刻划误差的影响,同时,采用了计算机系统控制测量过程,进行数据处理,实现了自动化测量,检测结果和误差曲线由打印机打印输出。     

深孔内含水炸药爆速和相对爆压的现场测试研究

长沙矿冶研究院和武钢大冶铁矿、本钢南芬露天铁矿合作进行了深孔内含水炸药爆速和相对爆压的测试研究。测试结果表明,运用改进的探针法—数字爆速仪和电气石压电晶体传感器－ 瞬态波形记录仪两种方法,可为改善破碎质量和大规模干扰降震提供可靠的数据     

电动振动台模型辨识方法及其应用的研究

电动振动台是振动与冲击环境试验的主设备,对其模型的辨识与估计是开展振动控制技术研究和振动试验仿真的必要环节。本文基于电动振动台的动力学和电学耦合模型,提出了一种以冲击信号作为激励的振动台模型传递函数进行系统辨识与参数估计的方法。并应用其模型参数完成了冲击波形的生成。仿真结果与试验结果一致性很好,表明本文所提出的模型辨识方法有效可行,对电动振动台试验波形的生成具有一定的实用价值     

A test system for calibrating flickermeters

This paper describes a new calibration system for testing flickermeters. The test system is used to generate and measure all the combinations of amplitude changes and frequencies required for calibrating flickermeters. Two computer-controlled waveform generators are used to produce the test conditions. The percent modulations of the test waveforms are measured with two high accuracy sampling voltmeters. Digital logic and software control ensures that the modulated signals are only measured when either maximum or minimum modulation occurs. Test data indicates that the percent modulation of the waveforms generated by the calibration system for square wave and sinusoidal modulations are within 0.002% and 0.005%, respectively, of the nominal values specified in IEC Standard 61000-3-3.     

心电图机检定仪ECG组合测试波形的检测识别

提出心电图机检定仪输出的ECG组合测试波形的检测识别方法,基于虚拟仪器技术,使用数据采集卡对ECG组合测试波形进行采集,通过LabVIEW编程实现心电图机检定仪ECG组合测试波形的各波段的幅值和时间间隔参数的检测和识别。     

基于嵌入式计算机的轻武器弹道测试技术

轻武器外弹道参数测试分析系统是以单板计算机技术为核心构建的参数测试软、硬件平台,具有信号调理、采集、分析处理、自动生成测试报告等功能,可以实现枪弹的初速、末速、全程飞行时间、立靶精度、弹药作用时间等多项参数的综合测试.系统硬件平台主要包括:嵌入式计算机、数据存储器、信号调理器、数据采集器、电源、显示终端等.传感器输出经过信号调理器处理后,由数据采集器转变成数字信号,并由计算机进行综合处理、弹道参数计算及统计分析,并生成试验报告.经实际使用证明,建立的测试系统具有高效、实时、自动化水平高、使用方便、可扩展等特点.