基于神经网络的模拟电路故障诊断研究

针对模拟电路,提出一种基于神经网络的故障诊断方法.通过故障字典的建立,选择电路的最佳测试节点,电路故障响应进行预处理后得到故障特征向量,再输入到神经网络实现电路故障诊断.仿真结果表明:该方法有效地解决了模拟电路辨识难的问题,具有更好的故障分辨率,取得了满意的诊断效果.     

模拟电路故障诊断的新故障字典法

基于节点电压灵敏度,将文献[1]中的线性无容差电路的故障字典法推广到可以诊断容差模拟电路和非线性电路软故障的新故障字典法。讨论了该方法的原理和字典的建立方法,给出了仿真实例。     

基于模式识别进行模拟电路故障诊断的方法

本文运用故障树分析法对模拟电路进行分析，按照电路结构对其按树枝形逐级划分建立故障集；将模式识别理论中的隶属函数法以及近邻法推广到可以进行模拟电路的故障诊断．讨论了该方法的原理以及建立字典进行诊断的方法，并给出了仿真实例。     

模拟电路中三极管和运放的软故障诊断

基于文献[1]中的斜率故障模型,提出了一种诊断模拟电路中晶体三极管和集成运算放大器软故障的字典法.在含有三极管和运放的电路中,通过对三极管和运放进行等效模型替代,对替代之后的等效电路,利用电路中的两节点电压增量计算出的斜率作为统一故障特征,建立故障字典,实现原电路中三极管和运放的软故障诊断.给出了三极管和运放的等效模型分析和诊断步骤,并用仿真实例证明了诊断方法的有效性.     

数模混合电路故障诊断方法的研究

随着电子技术的迅猛发展,电路系统的复杂程度急剧增加,越来越多的电路同时包含了数字信号和模拟信号,使得电路系统的测试难度越来越大,电路测试也因此面临着更大的挑战。目前的电路故障方法主要还是针对数字电路和模拟电路的,但是数模混合电路的测试仍然是一个很年轻的领域。针对目前数模混合电路测试的现状,对其故障诊断的各种方法的基本思想进行介绍。重点介绍基于DES理论的数模混合电路故障诊断。     

基于闭环集成运放的模拟电路模块级软故障诊断

基于斜率故障模型,提出了一种诊断模拟电路中基于闭环集成运算放大器的模块级软故障的字典法.在由闭环运放组成的模拟电路中,通过对电路以闭环运放及与其输入直接相连的元件看作一个整体划分模块,对各个模块中的任一元件或进行宏模型替代之后的运放等效电路,利用电路中的两节点电压增量计算出的斜率作为统一故障特征,建立故障字典,实现电路中相应模块包含的运放和所有元件的软故障诊断.给出了运放的等效宏模型和模块级软故障的诊断步骤,并用仿真实例证明了该诊断方法的有效性.     

一种诊断故障的新的测试节点选择法：混叠集分析法

本文根据存在容差时电路的特点,对现有的故障字典法作了改进。提出了一种能有效地解决有容差情况下最佳测试节点选取问题的新方法——混叠集分析法。对这种新方法进行了理论分析,提出了相应的算法,并在计算机上对实例进行仿真验证,证明该法是有效的。与基本的故障字典法相比,在很大程度上提高了诊断效率。     

可诊断容差模拟电路软故障的新故障字典法

基于支路屏蔽的原理,本文提出一种可以诊断容差模拟电路软故障的新故障字典法.文中讨论了该方法的诊断原理和字典的建立方法,给出了容差情况下的仿真诊断例子.     

浅谈模拟电路故障诊断的应用与发展

模拟电路的故障诊断的理论和方案经过多年的发展和应用,已经提出了很多有关模拟电路故障的诊断方法,主要有故障参数识别法、故障字典法和K故障诊断法。由于模拟电路本身的复杂性使得故障诊断技术的发展比较缓慢,研究出一套完善的诊断方法提高电路的可靠性具有十分重要的意义。     

开关电容网络的故障字典诊断算法

本文给出了一种开关电容网络(SCN)的故障字典诊断算法。该算法建立在电荷守恒原理基础上,它将SCN内各单故障,包括软故障和硬故障,划分到若干个故障集里。与传统的模拟电路的故障字典法不同,本算法可诊断软故障,计算量小,而且很容易推广到多时相SCN。     

A unified approach for fault simulation of linear mixed-signal circuits

The rapidly evolving role of analog signal processing has spawned off a variety of mixed-signal circuit applications. The integration of the analog and digital circuits has created a lot of concerns in testing these devices. This paper presents an efficient unified fault simulation platform for mixed-signal circuits while accounting for the imprecision in analog signals. While the classical stuck-at fault model is used for the digital part, faults in the analog circuit cover catastrophic as well as parametric defects in the passive and active components. A unified framework is achieved by combining a discretized representation of the analog circuit with the Z-domain representation of the digital part. Due to the imprecise nature of analog signals, an arithmetic distance based fault detection criterion and a statistical measure of digital fault coverage are proposed.This research was supported by the National Science Foundation under grant MIP-9222481.     

基于径向基函数神经网络的模拟/混合电路故障诊断

径向基函数神经网络是一种前馈型神经网络,具有较强的函数逼近能力和分类能力,学习速度快等优点.本文采用幅值恒定的正弦信号源进行模拟电路的故障仿真,从频域提取输出信号波形的特征值建立故障字典,应用径向基函数神经网络的这些优点进行响应分析和故障诊断,能够实现快速故障诊断及定位,具有准确率高的特点.     

On minimal set of test nodes for fault dictionary of analog circuit fault diagnosis

A method is proposed to obtain a minimal set of test nodes of an analog circuit for isolating all faulty conditions in the fault dictionary approach. Relevant theorem along with the proof is also given. Proposed method is extremely fast. This method is illustrated with an active filter circuit example.     

某型激光测距机故障诊断仪的设计

为解决部队条件下某型激光测距机故障维修难度大的难题,依据故障字典法的基本思想,通过分析该型测距机的电路特点和总结典型故障原因,结合故障诊断和维修经验,提出该型激光测距机故障诊断仪的设计方法。首先根据电路功能划分故障子集,其次由单片机产出激励信号并测试关键节点的信号,最后根据故障现象和测试结果编制故障字典。试用结果表明,该诊断仪能快速实现该型激光测距机整机功能和电路故障的诊断,提高了装备维修的效率。     

模拟电路故障诊断的结点电压灵敏度比值法

在证明线性电路中结点电压变化量比值等于结点电压灵敏度比值的基础上,提出了结点电压灵敏度比值法,通过结点电压变化量比值和结点电压灵敏度比值的比对确定电路的故障元件。理论分析和实验结果表明,该方法算法简单、诊断速度快,在可测点受限条件下具有较高的诊断精度,特别适合大规模线性模拟电路的故障诊断和测试。     

An Analog Circuit Fault Characterization Methodology

A methodology for diagnosing and characterizing multiple faults in analog circuits, and results from applying this methodology to a real circuit is presented. Our method is a novel combination of a Simulation Before Test (SBT) and Interpolation After Test (IAT) methodology. Our method uses the classical SBT concept of a fault dictionary database constructed before test. It also uses a method of IAT that consists in using the measurements to guide an interpolation algorithm to effectively increase the local resolution of the fault dictionary database and thereby yield the most likely test parameter value. Our methods underlying principle is to characterize the fault-free and faulty circuit cases by their impulse responses obtained by simulation and subsequently stored in a fault dictionary database. The method uses the technique of Lagrange interpolation to resolve the faults between the fault dictionary database entries and the actual measurements. Our experimental results reveal that the method is effective for characterizing faults when the simulations match the measurements sufficiently. Consequently, the methods effectiveness depends highly on the quality of the models used to build the dictionary as well as on the accuracy of the measurements.Yvan Maidon was born in Bordeaux, France. He received the M.Sc degree in (electronics) applied physics from the University of Bordeaux, in 1980. He is currently Head of the Department for Applied Sciences in Electrical and Electronic Engineering at the University of Bordeaux 1. His special research interests include failure analysis and relaibility of analog circuits. He has also developed original BICS for mixed circuits and SoC testing.Thomas Zimmer is currently Professor at the University of Bordeaux 1. He received the M.Sc. degree in physics from the University of Würzburg, Germany, in 1989 and the Ph.D. degree in electronics from the University of Bordeaux 1, France, in 1992. His research interests include characterization and modeling of high frequency bipolar devices. He has authored and co-authored about 70 scientific and technical publications including several book chapters. He is also co-founder of the start-up company XMOD.André Ivanov is Professor in the Department of Electrical and Computer Engineering, at the University of British Columbia. Prior to joining UBC in 1989, he received his B.Eng. (Hon.), M. Eng., and Ph.D. degrees in Electrical Engineering from McGill University. In 1995–96, he spent a sabbatical leave at PMC-Sierra, Vancouver, BC. He has held invited Professor positions at the University of Montpellier II, the University of Bordeaux I, and Edith Cowan University, in Perth, Australia. His primary research interests lie in the area of integrated circuit testing, design for testability and built-in self-test, for digital, analog and mixed-signal circuits, and systems on a chip (SoCs). He has published widely in these areas and holds several patents in IC design and test. Besides testing, Ivanov has interests in the design and design methodologies of large and complex integrated circuits and SoCs. Ivanov has served and continues to serve on numerous national and international steering, program, and/or organization committees in various capacities. Recently, he was the Program Chair of the 2002 VLSI Test Symposium (VTS 02) and the General Chair for VTS 03 and VTS 04. In 2001, Ivanov co-founded Vector 12, a semiconductor IP company. He has published over 100 papers in conference and journals and holds 4 US patents. Ivanov serves on the Editorial Board of the IEEE Design and Test Magazine, and Kluwers Journal of Electronic Testing: Theory and Applications. Ivanov is currently the Chair of the IEEE Computer Societys Test Technology Technical Council (TTTC). He is a Golden Core Member of the IEEE Computer Society, a Senior Member of the IEEE, a Fellow of the British Columbia Advanced Systems Institute and a Professional Engineer of British Columbia.     

模拟电路软故障诊断的研究

分析了模拟电路软故障诊断的重要性及现有的各种软故障诊断方法。对模拟电路软故障诊断字典法中基于支路屏蔽原理、电路参数随元件参数变化轨迹、节点电压灵敏度序列守恒定理和节点电压增量关系方程的四个研究方向各自的基本原理和优缺点进行了探讨;介绍了基于神经网络,结合模糊理论、小波变换的现代模拟电路软故障诊断的两个方向的研究现状;同时从通用的软故障诊断方法、大规模模拟电路的诊断策略和数模混合集成电路的诊断需求三方面指出了模拟电路软故障诊断的发展趋势和亟待解决的问题。     

Fault-based ATPG for linear analog circuits with minimal size multifrequency test sets

An automatic test pattern generation (ATPG) procedure for linear analog circuits is presented in this work. A fault-based multifrequency test approach is considered. The procedure selects a minimal set of test measures and generates the minimal set of frequency tests which guarantee maximum fault coverage and, if required, maximal fault diagnosis, of circuit AC hard/soft faults. The procedure is most suitable for linear time-invariant circuits which present significant frequency-dependent fault effects.For test generation, the approach is applicable once parametric tests have determined DC behaviour. The advantage of this procedure with respect to previous works is that it guarantees a minimal size test set. For fault diagnosis, a fault dictionary containing a signature of the effects of each fault in the frequency domain is used. Fault location and fault identification can be achieved without the need of analog test points, and just in-circuit checkers with an observable go/no-go digital output are required for diagnosis.The procedure is exemplified for the case of an analog biquadratic filter. Three different self-test approaches for this circuit are considered. For each self-test strategy, a set of several test measures is possible. The procedure selects, in each case, the minimal set of test measures and the minimal set of frequency tests which guarantee maximum fault coverage and maximal diagnosis. With this, the self-test approaches are compared in terms of the fault coverage and the fault diagnosability achieved.This work is part of AMATIST ESPRIT-III Basic Research Project, funded by CEC under contract #8820.