带微处理器电路板的故障测试系统

本文介绍了一种采用通用总线仿真方法对带微处理器电路板进行故障测试的系统，并对板上部分电路提出了诊断思路和实现方法。     

通用电路板自动故障诊断系统的设计与实现

针对传统电路板测试的局限性与单一性以及日趋灵活的电路板测试需求,基于矩阵开关技术、自动测试技术和虚拟仪器技术,设计并实现一种通用电路板自动故障诊断系统。该系统基于PCI总线技术所构建的通用硬件框架以及利用LabVIEW实现的上位机软件,实现通用电路板的直流电平测试、静态参数测试以及动态参数测试等,完成测量结果的对比分析、保存以及故障定位。实验证明:该系统能够快速准确地完成通用电路板的测试任务。系统搭建完成后,进行7次独立重复试验,测试结果显示:该系统测试数据的最大误差为±0.3%,同时具有性价比高、通用性好、可靠性高等优点,并且可以大大提高测试效率。     

适用于光伏电池的多通道I-V测试系统设计

为解决目前新型薄膜电池研究中光伏测试工作繁重的问题,本文提出开发一种适用于光伏电池的测试系统.该系统建立在软件控制电路开关基础上,可自动依次完成多个光伏电池样品的I-V测试;对相关的硬件电路板、电路控制开关、伏安特性测试软件的系统化设计进行了详细阐述;开发了具有多路复合开关的印刷电路板;完成了基于LabVIEW开发环境的软件设计.该系统通过RS232通信可完成I-V测试的参数设置、执行、数据采集和定时等功能.模块化设计保证了后期维护和测量通道扩展.基于该套系统,可以开展两线法和四线法测量,更高效地完成电池稳定性的数据采集.     

单片机控制电路板在线测试系统设计

本文设计了一套电路板的在线测试系统.该系统由一个缓冲箱、一个电源负载箱、一系列针床和相配套的软件组成.该系统可登录输入标准电路板在正常工作时的动、静态特性参数;登录后进行检测;最后经分析处理,给出电路板的动、静态特性.由此可在生产线上直接判别电路板的质量好坏.与传统在线测试技术相比,这套技术具有模拟外部条件而进行动态(程序工作)参数检测的功能,目前在国内处于领先地位.     

基于Android的气相色谱仪温度自动检定系统的设计

为实现自动检定气相色谱仪温度参数,设计了一套新型的温度自动检定系统。给出了温度数据采集仪的组成和模块设计,采用Android Studio开发环境,串口通信技术,完成了Java编程的Android手机端应用软件,实现了温度的测量和气相色谱仪的柱箱温度稳定性、程序升温重复性检定结果的自动检定。最后通过计量校准对温度数据采集仪准确性进行验证,在测量范围内示值误差均小于0.3℃,证明了该设计的可行性。与传统的检定方法相比,本文设计的气相色谱仪温度自动检定系统提高了工作效率,为检定人员减负减压。     

基于SOPC技术的电路板通用测试插槽设计

为实现用一个测试插槽检测多个不同的印刷电路板(PCB),提出了利用可编程器件(PLD)的在线重配置功能,运用可编程片上系统(SOPC)技术研发通用测试插槽的设计思想,完成了通用插槽的硬件设计和软件设计,包括:现场可编程门阵列(FPGA)中的独立接口模块设计、通用接口控制模块设计、系统层软件设计和应用层软件设计.实际应用结果表明:基于SOPC技术的通用插槽的研制有利于故障检测方法的实施,方便了电路板的自动测试,减小了测试设备的体积,增强了测试系统的通用性和可扩展性.     

基于自动测试系统的数字电路板测试与故障诊断

文章讨论了数字电路板故障诊断的原理和方法,介绍了自动测试系统在数字电路板测试与故障诊断中的应用,阐述了运用自动测试系统进行电路板故障诊断的结构。     

基于C#的高压自动校准系统

文章针对高压DHI系统所开发的自动校准系统,着重从设计目的、系统硬件设计、系统软件设计、数据处理、文件输出等方面作了详细介绍。该校准系统在Visual Studio环境下运用Visual C#语言完成编程。     

基于VEE的信号发生器自动校准软件

主要介绍了信号发生器校准系统的组成、自动校准软件的总体结构、软件设计方法和软件验证。该软件采用模块化设计,结构清晰;程控命令库和归一化测试流程设计解决了自动校准软件对各种型号信号发生器的兼容性问题;模板文件设计符合实际工作需要,数据集Data Set和Data Grid控件的设计实现了测试数据的存储和显示功能。结果表明,该软件实现了信号发生器的自动校准。     

基于DAQ的便携式电路板测试系统设计

为提高某型装备电路板的维修保障效率,设计了基于DAQ的便携式电路板测试系统。介绍了系统的硬件组成和工作原理,在分析激励发生、响应采集、数据处理等方面技术的基础上,讨论了故障诊断系统的设计。应用表明,该系统操作方便、便于携带,能够实现连续的数据采集、多任务同时执行、数字滤波、波形对比等功能。     

汽车道路综合试验系统数据采集与处理

为解决现有汽车道路试验系统便携性差、安装复杂等问题,开发一种基于Windows CE的便携式综合道路试验系统。该系统基于GPS、姿态航向参考系统XW-AHRS5100、测力方向盘、触摸显示屏等硬件平台,利用Visual Studio软件平台,使用C及C++编程语言完成汽车性能测试系统的软件编程,利于汽车动力性、制动性、操纵稳定性和平顺性等汽车道路试验。通过实车对比试验表明:该测试系统具有使用方便、操作简单、可移植性好、便携性强等优点,达到了预期目标和要求。     

火控系统故障测试仪研究

设计了一种针对火控系统性能和故障检测的测试仪,检测方式上分为全系统级检测、分系统检测和板级检测三种检测模式;基于全系统检测主要用于性能检测和故障检测,可将故障定位到分系统;基于分系统检测主要用于故障检测和分系统性能检测,可将故障定位到板级,板级检测主要对电路板性能和故障进行检测,可将故障定位到元器件级．硬件设计采用PC总线系统为平台,在此基础上构建测试仪的不同测试模式的接口模块,包括数字-轴角转换卡、轴角-数字转换卡和激励火控计算机系统．以C＋＋Builder为测试仪的软件开发环境,检测软件采用与硬件相适应的模块化结构,并根据硬件模块配置变化,自动配置软件环境．     

钟罩式气体流量标准装置检定系统软件设计

钟罩式气体流量标准装置检定系统(以下简称检定系统)软件是以钟罩式气体流量标准装置为基础,在Visual Studio 2005 C语言平台上,使用Access数据库开发的一套适用于日常流量计检定的应用程序。检定系统软件采用三层架构(界面层、中间层、数据库层)设计,其易用性、灵活性、扩展性都是较好的。本套软件集成了机械自动控制、装置自动测量、数据自动采集、现场数据记录、各种证书打印等功能,大大降低了检定员的劳动强度,提高了工作效率。     

一种AT91RM9200嵌入式开发平台设计

介绍了一种基于ARM9内核的工业级AT91RM9200芯片的嵌入式开发平台设计。重点讨论了硬件设计方案并给出了详细的开发流程。通过采用核心板＋扩展板的硬件架构，使用现场可编程逻辑器件扩展系统功能及接口，使得本系统既适合于初学者也适合于项目开发。通过例子使用者可以快速掌握系统架构，并具有建立基于ARM9内核芯片嵌入式系统设计的能力。系统还扩展了GPIB接口便于与通用测试仪器相连。     

A test of economic models of stopping policy in visual search

Optimization models of human visual search performance can be constructed that assume that the human operator maximizes an objective function, subject to given constraints. Two experiments were performed to validate one such optimization model, using ten students as the subjects. They were instructed to inspect printed circuit boards for one or two faults under different defective rates and cost structures.

It was discovered that human inspectors adopted a systematic search strategy. They stopped searching after either one or two complete scans of the circuit board, an optimal strategy in terms of the search economic model. Their stopping time was affected only by the fault type in a one-fault search. In two-fault search, two types of search strategies were apparent in subjects' performance. Four subjects searched for the easy fault first, then searched for the difficult fault. Six subjects searched for both faults simultaneously. The Embedded Figures Test (EFT) was found to categorize these two types of subjects.     

Hybrid free-space optical bus system for board-to-board interconnections

A free-space optical bus system is described for board-to-board interconnections at the backplane level. The system uses active optoelectronic modules as the interface between the circuit boards and the electrical backplane. Substrate-mode holograms are used to implement signal broadcast operations between boards, and each board on the backplane shares common free-space channels for transmitting and receiving signals. System-design considerations are given, and the potential performance of the optical bus system is evaluated. An experimental demonstration is also presented for the signal broadcast operation through cascaded substrate-mode holograms at a data rate of 622 Mb/s.     

Analog fault diagnosis of actual circuits using neural networks

We have developed a neural-network based analog fault diagnostic system for actual circuits. Our system uses a data acquisition board to excite a circuit with an impulse and sample its output to collect training data for the neural network. The collected data is preprocessed by wavelet decomposition, normalization, and principal component analysis (PCA) to generate optimal features for training the neural network. This ensures a simple architecture for the neural network and minimizes the size of the training set required for its proper training. Our studies indicate that features extracted from actual circuits lie closer to each other and exhibit more overlap across fault classes compared to SPICE simulations. This implies that the neural network architecture which can most reliably perform fault diagnosis of actual circuits is one whose outputs estimate the probabilities that input features belong to different fault classes. Our work also shows that SPICE simulations can be used to select appropriate features for training the neural network. Reliable diagnosis of faults in an actual circuit, however, requires training data from the circuit itself. Our fault diagnostic system, trained and tested using data obtained from real sample circuits, achieves 95% accuracy in classifying faulty components     

Pyrolysis characteristics of integrated circuit boards at various particle sizes and temperatures

A pyrolysis method was employed to recycle the metals and brominated compounds blended into printed circuit boards. This research investigated the effect of particle size and process temperature on the element composition of IC boards and pyrolytic residues, liquid products, and water-soluble ionic species in the exhaust, with the overall goal being to identify the pyrolysis conditions that will have the least impact on the environment. Integrated circuit (IC) boards were crushed into 5-40 mesh (0.71-4.4mm), and the crushed particles were pyrolyzed at temperatures ranging from 200 to 500 degrees C. The thermal decomposition kinetics were measured by a thermogravimetric (TG) analyzer. The composition of pyrolytic residues was analyzed by Energy Dispersive X-ray Spectrometer (EDS), Inductively Coupled Plasma Atomic Emission Spectrometer (ICP-AES) and Inductively Coupled Plasma-Mass Spectrometry (ICP-MS). In addition, the element compositions of liquid products were analyzed by ICP-AES and ICP-MS. Pyrolytic exhaust was collected by a water-absorption system in an ice-bath cooler, and IC analysis showed that the absorbed solution comprised 11 ionic species. Based on the pyrolytic kinetic parameters of TG analysis and pyrolytic residues at various temperatures for 30 min, the effect of particle size was insignificant in this study, and temperature was the key factor for the IC board pyrolysis. Two stages of decomposition were found for IC board pyrolysis under nitrogen atmosphere. The activation energy was 38-47 kcal/mol for the first-stage reaction and 5.2-9.4 kcal/mol for the second-stage reaction. Metal content was low in the liquid by-product of the IC board pyrolysis process, which is an advantage in that the liquid product could be used as a fuel. Brominate and ammonium were the main water-soluble ionic species of the pyrolytic exhaust. A plan for their safe and effective disposal must be developed if the pyrolytic recycling process is to be applied to IC boards.     

Efficient operation methods for a component placement machine using the patterns on printed circuit boards

Operation of a PCB assembler is complicated to optimise since it requires simultaneous consideration of a component's rack assignment and component mounting sequencing. However, most previous researches considered the constraints separately on the optimisation process. Two different methods using special features on printed circuit boards are developed and presented in this research. Based on results from field surveys, it is found that identical components are positioned closely with each other or identical single boards are repeatedly printed on one big board to enlarge up to a proper size to be assembled in the machine. These patterns are adapted on the design of assembly methods to increase productivity. Simulation models are constructed using Visual C++ for performance evaluation purposes of the developed heuristics.     

超高强钢热冲压工艺信息化管理系统搭建研究

目的 解决超高强钢热冲压工艺参数多且参数调整范围大,造成热冲压工艺设计难度大的问题。方法 以微软SQL Server数据库和ASP.Net Core为平台,通过Visual Studio C#集成开发环境进行B/S（浏览器/服务器）架构程序开发。结果 实现了集成普通板、补丁板、拼焊板、软硬分区板、不等厚板、其他板共6类板材,15种零件类型,以及相关的零件信息、产品要求、制造工艺、材料属性、供应商、产线、设备等7类数据信息的超高强钢热冲压工艺信息化管理系统软件。结论 该系统实现了超高强钢热冲压工艺数据录入与存储,多种数据信息相互关联、按需检索与联合查询以及用户管理和维护功能,为国内超高强钢热冲压工艺技术研究与产品开发提供系统架构参考。