基于故障物理的电子产品可靠性仿真分析方法

基于故障物理的电子产品可靠性仿真分析方法首先对产品进行故障模式、机理与影响分析（FMMEA）,得到所有潜在故障点的故障模式、机理与对应的物理模型.利用产品材料、结构、工艺、应力等参数建立产品的仿真数字模型,并进行应力分析,利用概率故障物理（PPoF）模型进行损伤分析,得到各潜在故障的寿命分布.最后利用时间竞争的原理对其进行数据融合,得到产品故障率、平均故障间隔时间（MTBF）等可靠性指标.通过某型单板计算机的可靠性仿真过程说明了该方法的实施流程.这种基于故障物理的可靠性仿真的方法从微观角度将可靠性与产品的结构、材料及所承受的应力联系在一起,有助于发现产品的薄弱环节并采取切实有效的措施,是目前基于手册数据的可靠性预计方法的有益补充.     

基于数字化样机的电子产品可靠性设计分析方法

当前航空装备普遍采用数字化研制模式,为引入可靠性仿真等先进技术带来了机遇。基于故障物理理论,以电子产品的设计信息和预期工作环境作为输入,利用建模与仿真方法对产品在寿命环境下的应力特性进行分析;结合应力损伤模型进行故障预计,得到产品的故障信息矩阵,从而提出了一种基于产品数字化样机的可靠性设计分析方法。针对某航空电子设备的应用验证结果表明,利用该方法可以发现产品可靠性薄弱环节,提出的具体预防对策可指导设计改进,达到消除潜在故障以提高产品可靠性的目的。     

结构可靠性设计与安全系数法的分析与比较

结构产品可靠性与电子产品可靠性的工作目标都是要求在规定的使用条件和时间内不产生破坏或功能失效的能力.电子产品的失效模式比较成熟,易于预计;结构产品的失效模式比较复杂,难于预计.目前,结构产品可靠性大都采用结构可靠性设计或者安全系数法设计方法.文中对这两种结构设计法进行分析比较,结果证明:以概率论为理论基础的结构可靠性设计方法比常规的安全系数法更为合理,从根本上能够满足产品的可靠性、安全性、经济性设计要求,并能很好地保证产品的可靠性和质量.     

可靠性仿真试验及其在雷达研制中的应用

可靠性仿真试验是基于故障物理原理和计算机技术,利用计算机仿真分析软件,对雷达等电子设备进行数字模型可靠性分析和计算的过程。通过软件在电子样机上施加产品所经历的载荷历程,分解到产品的基本模块上,进行应力分析和应力损伤分析,从而找出产品的设计薄弱环节;通过仿真预计产品的失效时间分布并分析,指导和辅助可靠性设计优化;通过可靠性仿真量化评估,比较设计方案,为可靠性综合评价提供支持。研究表明：可靠性仿真试验缩短了雷达研制周期,提高了雷达可靠性水平。     

一种星载电子产品老练试验加速因子估计方法

提出一种基于可靠性预计数据的星载电子产品老练试验加速因子的估计方法。在该方法中,温度对产品失效过程的影响通过器件失效率预计模型中的温度应力参数予以刻画。通过比较产品在工作环境温度与老练试验温度下的预计失效率数据来估计老练试验加速因子。该方法简单、易行,含义明确,有望增强可靠性评估结果与可靠性预计结果的可比性。     

基于蒙特卡罗的电子产品可靠性分析

由于产品技术性能和结构要求等方面的提高,可靠性问题愈显突出,文章对电子元器件的可靠性进行了分析。寿命试验是可靠性试验中最重要最基本的项目之一,它是将产品放在特定的试验条件下考察其失效(损坏)随时间变化规律,寿命测试分析方法采用威布尔型分析方法,根据极大似然估计的不变原则,统计出元件的平均寿命的极大似然估计,另外采用指数分布,属于伽玛分布和威布尔分布的特殊情况,统计产品的偶然失效。实验仿真给出了数据,其目的在于提高电子产品的可靠性。     

基于EDA的电子产品一体化设计分析技术

以故障仿真分析为核心的可靠性与性能一体化设计分析技术,是一项电子产品研制阶段及时发现设计缺陷并有效提升产品固有可靠性的重要技术.简要回顾了相关技术的发展,分析了高可靠电子产品对该技术的需求,阐述了应用电子设计自动化（EDA）工具实现电路性能和可靠性的一体化设计的技术流程,给出了以故障仿真分析为核心实现电路一体化设计的思路.最后着重介绍了建立电路可靠性与性能一体化设计与仿真分析环境时面临的故障建模、故障注入、故障判别、数据接口、仿真效率等关键技术的解决方法,为该技术实现工程实用性提供了重要支持.     

应用PDCA实现湿度敏感器件的有效控制

伴随信息技术快速发展与电子产品的普及和应用,电子产品的使用寿命和可靠性越来越成为人们关注的焦点。在电子产品的制造过程中,ESD(静电放电)和MSD(湿度敏感器件)成了威胁电子产品质量的两大重要因素,直接影响产品测试的直通率和产品的可靠性。MSD器件的失效像ESD破坏一样,具有一定的隐蔽性。MSD失效在测试过程中,也不一定会表现为完全失效。在各种诱发器件失效的机制中,MSD失效在电子制造过程中占据相当高的比例。在审核多家SMT工厂过程中发现,MSD的控制远比ESD的防护要薄弱。文章从工作实践出发,探讨应用PDCA全面质量管理的思路来实现电子产品制造过程中湿度敏感器件的有效控制。     

可靠性工程与环境工程

0306932MTBF 预计值用于定时截尾试验方案的选择[刊]/朱起悦//电子产品可靠性与环境试验.—2002,(5).—55～57(D)提出选择定时截尾可靠性鉴定试验方案时,引入平均故障间隔时间(MTBF)预计值θ_p,通过计算定时截尾试验方案的接收概率,并结合试验时间和试验经费,科学、合理地选定定时截尾可靠性鉴定试验方案。参2     

无线通信产品的可靠性预计与实现

针对消费类电子产品的可靠性预计方法Bellcore-SR332的缺陷,提出一种以产品现场返还数据进行失效率建模,以产品开发过程中各可靠性活动的结果作为输入变量的可靠性预计方法,从而弥补可靠性预计与产品开发过程结合的不足,为可靠性预计提供更为真实、准确的预计方法。同时,结合可靠性理论知识在无线通信产品返还数据分析的结合,提出一套符合无线通信产品的返还率预测方法。     

Clustering hypervisors to minimize failures in mobile cloud computing

Resource virtualization has become one of the key super‐power mobile computing architecture technologies. As mobile devices and multimedia traffic have increased dramatically, the load on mobile cloud computing systems has become heavier. Under such conditions, mobile cloud system reliability becomes a challenging task. In this paper, we propose a new model using a naive Bayes classifier for hypervisor failure prediction and prevention in mobile cloud computing. We exploit real‐time monitoring data in combination with historical maintenance data, which achieves higher accuracy in failure prediction and early failure‐risk detection. After detecting hypervisors at risk, we perform live migration of virtual servers within a cluster, which decreases the load and prevents failures in the cloud. We performed a simulation for verification. According to the experimental results, our proposed model shows good accuracy in failure prediction and the possibility of decreasing downtime in a hypervisor service. Copyright © 2017 John Wiley & Sons, Ltd.     

Estimation of Reliability from Multiple Independent Grouped Censored Samples with Failure Times Known

Failure times of one type aircraft-engine component were recorded. In addition, life times are periodically recorded for unfailed engine components. The data are considered as multiple s-independent grouped censored samples with failure times known. The assumed failure model is the 2-parameter Weibull distribution. Maximum likelihood estimates are derived. The exponential model is used for comparison. Monte Carlo simulation is used to derive s-bias and mean square error of the estimates. The asymptotic covariance matrix was computed for the sampling conditions studied. The maximum likelihood estimates of the reliability were obtained as a function of component operating time since overhaul.     

基于GIS单线图的配网停电单模拟操作应用研究

配电网停电会造成电力系统供配电可靠性以及服务质量下降,研究基于地理信息系统(GIS)单线图的配网停电单模拟操作应用。利用网格长度作为基本单位建立坐标系,以选取起始点与终止点为基础,通过四参数法将GIS坐标映射至图纸网格内,实现配网内设备初步布局,将杆塔、站房和整体均匀分布作为优化目标,设置多目标优化目标函数实现GIS单线图最终优化。选取某电力公司配网作为单模拟操作应用对象,模拟结果表明,单模拟操作配网停电后,该配网各负荷点年故障率、次平均停电时间以及年停电时间均有所减少,可有效提升配网的供配电可靠性。     

Thermal reliability prediction and analysis for high-density electronic systems based on the Markov process

Thermal-mechanical fatigue is one of the main failure modes for electronic systems, particularly for high-density electronic systems with high-power components. Thermal reliability estimation and prediction have been an increasing concern for improving the safety and reliability of electronic systems. In this paper, we propose a stochastic process prediction model to estimate the thermal reliability of an electronic system based on Markov theory. We first divided the high-density electronic systems into four modules: the energy transformation and protection module, the electronic control module, the connection module, and the signal transmission and transformation module. By integrating failure and repair characteristics of the four modules, a stochastic model of thermal reliability analysis and prediction for a whole electronic system was built based on the Markov process. The feature parameters of thermal reliability evaluation, including thermal reliability, thermal failure probability, mean time between thermal faults, and thermal stable availability, were derived based on our comprehensive model. Finally, we applied the model to an indoor electronic system of DC frequency conversion conditioning. The thermal reliability was estimated and predicted using tested failure and debugging repair data. Effective methods for improving thermal reliability are presented and analyzed based on the comprehensive Markov model.     

基于LSSVM的小子样元器件寿命预测

现代高可靠元器件在寿命试验时会出现失效数据很少的小子样情形,而传统的可靠性评估方法需要大量的失效数据,针对此情况,从工程实践的实际需求出发,提出了基于最小二乘支持向量机的小子样元器件寿命预测方法。该方法通过建立最小二乘支持向量机模型,从而可根据已知元器件的失效时间去直接预测同一批未失效元器件的失效时间。将该方法应用于热载流子效应引起MOS管退化失效的加速寿命试验中进行MOS管失效时间的预测,结果表明基于最小二乘支持向量机的寿命预测方法在进行小子样元器件的寿命预测时具有很高的精确度。     

Incorporating fault debugging activities into software reliability models: a simulation approach

A large number of software reliability growth models have been proposed to analyse the reliability of a software application based on the failure data collected during the testing phase of the application. To ensure analytical tractability, most of these models are based on simplifying assumptions of instantaneous & perfect debugging. As a result, the estimates of the residual number of faults, failure rate, reliability, and optimal software release time obtained from these models tend to be optimistic. To obtain realistic estimates, it is desirable that the assumptions of instantaneous & perfect debugging be amended. In this paper we discuss the various policies according to which debugging may be conducted. We then describe a rate-based simulation framework to incorporate explicit debugging activities, which may be conducted according to the different debugging policies, into software reliability growth models. The simulation framework can also consider the possibility of imperfect debugging in conjunction with any of the debugging policies. Further, we also present a technique to compute the failure rate, and the reliability of the software, taking into consideration explicit debugging. An economic cost model to determine the optimal software release time in the presence of debugging activities is also described. We illustrate the potential of the simulation framework using two case studies.     

Software Reliability Analysis and Measurement Using Finite and Infinite Server Queueing Models

Software reliability is often defined as the probability of failure-free software operation for a specified period of time in a specified environment. During the past 30 years, many software reliability growth models (SRGM) have been proposed for estimating the reliability growth of software. In practice, effective debugging is not easy because the fault may not be immediately obvious. Software engineers need time to read, and analyze the collected failure data. The time delayed by the fault detection & correction processes should not be negligible. Experience shows that the software debugging process can be described, and modeled using queueing system. In this paper, we will use both finite, and infinite server queueing models to predict software reliability. We will also investigate the problem of imperfect debugging, where fixing one bug creates another. Numerical examples based on two sets of real failure data are presented, and discussed in detail. Experimental results show that the proposed framework incorporating both fault detection, and correction processes for SRGM has a fairly accurate prediction capability.     

基于元器件应力法的电能表可靠性预计报告

元器件应力法是目前最适于电子式电能表可靠性预计的工程实用方法。文中分析了单相智能电能表可靠性预计的基本目标,基于GJB/Z299C-2006手册建立可靠度模型,进行可靠性分配,计算元器件失效率和平均工作寿命,为定量预计电能表可靠性建立了基本框架。     

Concept of smart integrated life consumption monitoring system for electronics

In situ diagnostics or prognostics of electronics are based on environment monitoring and reliability computation associated to experienced loads. As health assessment is a major concern for improving the maintenance process, it has to be known as soon as possible to be able to react according to the health status prediction. Indeed, the speed needed for failure prediction calculation from the stress monitored to the warning reported is essential to prevent ongoing operation of an electronic system on the way to failure. Real time on-board calculation is then the main objective in order to avoid regular data downloads and ground-based analysis.This paper presents a smart and integrated micro-programmable life consumption monitoring system (LCMS). The latter embeds sensors and on-board processing capabilities for advanced prognostics of printed wired assemblies (PWAs). Based on a methodology using physics of failure (PoF), it can provide, in real time, the life consumption prediction of electronics. The reliability of the LCMS is also tackled before presenting the real monitoring experiment. Finally, the future trend of such monitoring tools is discussed.