ispPAC、CPLD技术在微型测试系统中的应用

将可编程器件用于硬目标侵彻过载参数测试系统.该系统选用xilinx公司的最新产品coolrunner cpld系列可编程器件和lattice半导体公司推出的可编程模拟器件ispPAC.详细介绍了cpld、isppac的性能,系统的组成和工作原理,测试系统电路框图及系统工作状态图,并研究了其低功耗与微型化的实现.     

加速度计电路组件自动测试系统研制

某型号加速度计电路组件自动测试系统可实现电路组件A测试、电路组件B测试及AB联测。本文介绍了该测试系统的测试原理、结构组成、硬件设计及软件设计。运用多功能数据采集卡的A/D功能实现了对多个电路组件进行同时测试;运用其D/A输出加分压电路完成了对电路组件A输入电压的闭环动态调节,以实现对电路组件A进行增益测试。采用VC++6.0完成了测试软件的开发。     

专用测试系统校准技术探讨

测试系统是执行测试任务的传感器、仪器和设备的总称.专用测试系统量值控制和测量不确定度的控制对保证型号产品质量有十分重要的意义.专用测试系统校准方法的研究是国防军工计量的工作重点之一.本文针对专用测试系统的特点、现状、以及校准工作存在的问题,进行了分析研究.对专用测试系统的校准方法及测量不确定度评定进行了适当的探讨.     

多轴运动控制系统的通用化设计租应用

根据飞行器测试系统的实际需要,阐述了一种通用化的多轴运动控制系统的设计实现,该系统主要包含控制电路、驱动电路和反馈电路,并介绍了该系统在某型号飞行器测试系统中的实际应用。     

电子节气门硬件在环仿真测试方法研究

电子节气门被广泛地应用于汽车发动机中,其设计越来越受到重视.采用硬件在环仿真测试可大大缩短电子节气门的研发、标定时间.借助汽车电控系统快速原型开发环境(MACS565),建立了电子节气门的硬件在环仿真测试平台.利用Matlab/Simulink建立了仿真测试模型,实现了电子节气门硬件在环仿真和性能测试.利用此平台完成了某型号电子节气门传感器输出特性的测试方法研究及相关参数的测定工作.该测试平台为电子节气门新产品的开发与性能检测提供了测试手段,同时可作为产品在线质量检测系统的原型.     

基于虚拟仪器的继电器测试系统开发

为提高继电器测试系统的稳定性和可靠性,设计了以电磁继电器为主要测试对象的自动测试系统,介绍了其总体设计方案,阐述了在继电器测试标准中定义的继电器时间参数、触点接触电阻、线圈电流、动作值及释放值等主要参数的测试原理、方法及实现。对测试标准中给定的测试电路进行了实际应用,得到了主要参数的相应数据和曲线。系统采用模块化设计,满足不同型号继电器的多参数测试需求。测试结果表明,该系统直观、性能可靠、测试速度快,能够满足常规继电器的测试要求,且界面具有良好的人机交互性,在有效提高工作效率的同时成本大降。     

基于 LabVIEW 的 SIZE3直流接触器性能检测系统

基于虚拟仪器LabVIEW平台，选用某公司SIZE3型号直流接触器作为试验对象，开发了基于Lab-VIEW软件的接触器性能测试系统。功耗瞬间采集波形表明，本文所开发的直流接触器的性能测试系统是可行的；两处尖峰检测结果表明，接触器内部电路性能稳定；高低电平电压转换，表明接触器可以及时接通和释放电压，保护电路安全。测试系统可通过上位机进行控制并记录相关试验数据，可实现批量、自动和精准的检测，有较高的实用价值。     

常规火箭弹药燃烧室温度和压力测量系统设计

本文提出了以常规火箭弹药燃烧室为研究对象,以热电偶、压力传感器、采集电路和存储单元为核心,借助C8051F单片机的片内AD功能,记录燃烧室温度和压力变化的数据记录系统。文章介绍了系统组成,工作原理及其设计方法,对供电电路、采集电路和存储单元等电路进行了详细说明。该测试系统可直接作为常规火箭弹药燃烧室综合性能测试的一部分,测试数据有助于设计导流装置以及采取防护措施。     

汽车碰撞实验车载测试系统中数据存储的实现

FLASH 存储器以其体积小、容量大、可随机访问等优点可以方便地应用于汽车碰撞试验中. 采用 FLASH 存储器作为车载测试系统数据存储介质, 研究了基于 FLASH 存储器的控制电路及车载式测试系统在汽车碰撞试验中的应用. 论述了测试系统总体设计思想;设计了与 FLASH 存储器的数据存储特点相匹配的数据双缓冲电路, 以及对 FLASH 存储器的数据进行写入、读出、擦除等操作的中心控制电路;并且设计了测试系统实现所有功能的软件流程.     

军用航空型号产品专用测试设备全过程计量保证研究

军用航空型号产品专用测试设备作为型号研制试验过程非通用测试设备,需要辅以对应的计量保证工作,以确保专用测试设备的研制配套与型号研制相同步,保证专用测试设备试验数据准确可靠、真实可信。本文着眼于军用航空型号产品专用测试设备研制配套全过程,准确把握型号专用测试设备计量保证工作特点,以"融入型号,强化过程,重点把控"为指导原则,系统地梳理了军用航空型号产品专用测试设备研制配套全过程计量保证关键任务,并提出了进一步做实型号专用测试设备计量保证工作的合理化建议。     

Estimation of Parameters of Universal Distribution of Moments of Failure of Products

A method is proposed for estimating the parameters of a mixture of exponential and Weibull distributions for which the accuracy of preliminary estimates obtained by graphical analysis is refined in accordance with the criterion of maximum likelihood. The efficiency of the proposed method is supported by the results of statistical modeling.     

Assessment of intakes of mixtures of radionuclides

Australia has several uranium mines and a large number of mineral sand mines, with associated processing facilities. Exposures resulting from these mining and processing operations usually involve intakes of mixtures of radionuclides. This work describes the development of a suite of first order, linear compartment models, based on the ICRP Publication 66 respiratory tract model, and an analytical solution to the decay equations, for assessing the consequences of such intakes. The computer programs based on these models directly compute excretion, organ retention and organ and whole-body doses for intakes of either single radionuclides or any mixture of radionuclides belonging to the same radioactive decay chain. The intake can be via inhalation, ingestion or injection, and can be acute, chronic or of limited duration. The starting concentration and degree of secular (dis)equilibrium can be specified for each radionuclide. No assumptions need to be made about the relative magnitudes of the radioactive half-lives of the different nuclides.     

Analysis of the rate of propagation of the wave of change of boiling modes

An approximate analytical expression is derived for the velocity of the front of the wave of change of boiling modes on a rod and on a plate. The impact of the Thomson effect and of the heater orientation in the gravity field is included. Adequate agreement is demonstrated between the derived relations and experimental data.     

Evaluation of optical properties of highly scattering media by moments of distributions of times of flight of photons

A novel method for the determination of the optical properties of tissue from time-domain measurements is presented. The data analysis is based on the evaluation of the first moment and the second centralized moment, i.e., the mean time of flight and the variance of the measured distribution of times of flight (DTOF) of photons injected by short (picosecond) laser pulses. Analytical expressions are derived for calculation of absorption and of reduced scattering coefficients from these moments by application of diffusion theory for infinite and semi-infinite homogeneous media. The proposed method was tested on experimental data obtained with phantoms, and results for absorption and reduced scattering coefficients obtained by the proposed method are compared with those obtained by fitting of the same data with analytical solutions of the diffusion equation. Furthermore, the accuracy of the moment analysis was investigated for a range of integration limits of the DTOF. The moment analysis may serve as a comparatively fast method for evaluating optical properties with sufficient accuracy and can be used, e.g., for on-line monitoring of optical properties of biological tissue.     

Numerical study of methods of linearization of the output characteristics of radio-frequency sensors of the level of dielectric media

Different constructions of the sensing elements of radio-frequency level sensors based on sections of long lines are numerically investigated by means of the Matlab program for the purpose of minimizing the measurement error caused by the nonlinearity of the output characteristic. It is shown that the nonlinearity is lowest for U-shaped designs. The nonlinearity factor KN may be regulated by varying the capacitance of a correcting capacitor connected to the input of the sensing element and (or) the length of one of the sections of the long line. In selecting an optimal capacitance of the correcting capacitor KN ≤ 0.15% for control media with dielectric permittivity in the range 2.2–30.     

Possibilities of Decreasing the Errors of Determination of the Height of the Pole of a Sessile Drop of Melt

We analyze the possibilities of decreasing the errors of measuring the height of the pole of a sessile drop of melt above its equator by determining the position of the equator according to the midpoints of vertical chords of the image of the drop. The optimal distance between these chords and the edge of the image of the drop is chosen within 10–20% of the radius of the equator. The proposed method guarantees the same level of errors of evaluation of the height of the pole and the radius of the equator, which enables one to substantially increase the accuracy of evaluation of the capillary constant and the surface energy of the melt according to the geometric parameters of the sessile drop.     

Analysis of anisotropy of properties on the basis of studies of texture of coarse-grained ingots of thermoelectric materials

An analysis of anisotropy of the properties of a Bi₂Se_0.3Te_2.7 solid solution was carried out using construction of demonstrative surfaces for thermoelectric effectiveness and thermal expansion coefficients. It is shown that the texture is an important factor forming anisotropy of properties and technological fitness of ingots for manufacturing modules. Anisotropy of properties based on the studies of the ingot textures obtained using the float-zone method and Bridgman method (growing thermoelectric plates in a flat cavity) was studied.     

Estimation of potentialities of methods of summation of direct measurement errors

Conventional methods for summation of direct measurement errors are considered. Conditions under which these methods provide consistent results are stated. It is proposed to utilize for characteristic of the total error, its interval estimator or the half-sum of the value obtained by adding up its arithmetic and geometric random errors.Translated from Izmeritel'naya Tekhnika, No. 4, pp. 10–12, April, 1995.