可靠性预计方法及思考

本文介绍了可靠性预计的目的,并对当前较为常见的可靠性预计模型或方法做了比较和说明,也对造成可靠性预计局限性的原因做了分析,最后对在可靠性工程工作中对待可靠性预计的态度做了探讨.     

复杂系统进行快速的可靠性预计和设计

重视可靠性设计,开发与应用快速、实用的预计和设计软件,是落实可靠性工程的必要条件。对已经开发成功的、可以快速地进行复杂系统可靠性预计和设计的软件进行了示例介绍。     

非接触式智能卡可靠性预计模型及软件

根据非接触式智能卡的结构,对智能卡中各个模块的可靠性进行分析,建立了非接触式智能卡的可靠性预计模型,对整个智能卡的最终稳定状态进行预估计算,在此基础上,开发了非接触式智能卡的可靠性预计软件,并简单介绍了软件的性能。     

表决冗余系统可靠性预计的非递归实现

介绍一种ｎ中取ｋ表决冗余系数（ｋ／ｎ）可靠性预计的非递归算法，文中就ｋ／ｎ系数的定义，递归算法与非递归算法的实现及其优劣进行了重点论述。     

某型号观瞄系统可靠性预计

本文阐述了某型号观瞄系统可靠性初步预计的全过程，是基层可靠性工作者的实践总结。     

侵彻引信电路的可靠性预计

引信电路的可靠性预计在整个引信设计过程中起着重要的作用。可靠性的预计是一个复杂的工程,其中包括可靠性参数的选择、可靠性模型的建立以及可靠性的计算。在不同的引信设计阶段,应采用不同的预计方法。为了得到引信电路的可靠性,根据设计的引信电路,绘制了引信的可靠性框图,选取合适的可靠性参数,运用不同的可靠性预计方法,对处于不同设计时期的电路可靠性进行了预计。     

考虑结构多失效模式的电动舵机系统可靠性预计

针对以往试验中出现多种模式的结构失效现象,在对新型舵机系统进行可靠性预计时,有必要在传统电子学预计基础上,加入多失效模式下结构可靠性预计。首先,采用专家评分分配法将系统可靠性指标分配到相应模块与组件,然后由元器件计数法、均值一次二阶矩法分别得到电子学部分与各失效模式下结构部分的可靠性指标,进而得到系统的可靠性指标。从预计结果看出,设计方案达到总体分配到舵机系统的可靠性指标要求,在考虑滚珠丝杆机构多失效模式下的可靠度要低于其他电子学部分,与以往试验中结构失效多于电子学部分的现象较为吻合。     

可靠性预计及其准确性

针对可靠性预计准确性的争论,分析了可靠性预计的方法及标准的数据内涵,指出由于预计手册表征的是不同国家、地区的元器件可靠性水平,根据不同的预计方法(手册)来预计同一设备,因结果不同而得出可靠性预计不准确的结论是不妥当的.验证一个预计手册是否准确的唯一标准是被预计设备的现场MTBF值是否同预计值接近.影响预计准确性的因素包括预计手册本身的准确性、预计标准选取的合理性、预计数据的真实性、预计技术的准确使用等.在可靠性预计中,要正确地认识可靠性预计与其它可靠性工作的关系,不能把可靠性预计的作用同其它可靠性分析方法的作用相混淆;要客观地认识可靠性预计的局限性,认真区分预计误差与预计错误,不可以偏概全.     

美国军用手册338B中的软件可靠性预计模型及其应用

介绍美国军用手册338B中软件可靠性以及软件可靠性预计,具体讨论四种软件可靠性预计模型——Musa执行时间模型、Putnam模型、以及罗马实验室的RL-TR-92-52模型与RL- TR-92-15模型,并给出其适用条件和应用例子。     

某测控系统软件的可靠性预计

论述了运用两种NHPP增长型模型进行某测控系统软件可靠性预计的方法,以及它们的数学解析式,并阐明了两者的关系。针对某发射测控系统软件的测试调试过程,初步估计了软件的程序窖量。根据所得到的数据。运用两种NHPP模型计算了模型参数的估计值。预测了软件的可靠性水平和需要进行的各项软件测试的时间。     

Microelectronic System Reliability Prediction

The paper reviews the US MIL-HDBK-217 (MH-217) method of part stress-analysis failure-rate prediction for microelectronic systems and investigates the extent to which the MH-217 failure-rate formula is compatible with the physics of actual failure modes. A new formula is proposed which takes account separately of the reliability of the microelectronic devices in a system and of the system-level determinants of reliability. It is simpler than the current MH-217 formula, and more useful. It enables the system level aspects such as reliability program activities to be taken into account in the prediction, and allows better correlation to be made between part test and system test data. An example applies the new formula to a typical microelectronic system. By considering separately the failure physics of parts and the system level determinants, reliability prediction can be made a more useful tool both for part stress analysis and for reliability program management. The model would enable better correlations to be made between part and system test results. More work needs to be done to refine and validate the parameters. For high-reliability programs with closely controlled maintenance or with no maintenance, the use of a decreasing failure rate model for part failures should be considered. The failure rate formulae for other electronic parts used in microelectronic systems would also need to be reviewed, but apart from removal of the environmental factor and reduction in the failure rate values proportionate to that proposed for microelectronic parts, no changes should be necessary.     

系统可靠性预计的方法

介绍了系统可靠性预计的多种方法，不同的工程阶段对可靠性预计的要求不同，因此预计的目的和用途也不同，相应的就有不同的预计方法。最后介绍了工程中研制复杂系统时在早期设计阶段用于粗略快速预计的方法。     

基于RBF神经网络的组合导航软件可靠性滚动预测

针对组合导航系统软件可靠性的预测问题,研究了系统累积故障数与系统运行时间的关系,提出一种基于RBF神经网络的软件可靠性预测模型,取得了理想的短期预测效果。为了获得较好的长期预测效果,采取滚动式训练、在线调整网络结构的方法对之加以改进。仿真结果表明,该模型拟合精度优于J-M模型、与G-O模型相当,预测精度高;该模型不需假...     

基于CARMES的电路故障仿真与最坏情况分析技术

电路故障仿真及最坏情况分析是实现产品性能与可靠性协同设计的重要方法。介绍了电路故障仿真的基本原理,探索了EDA软件接口、故障建模、故障注入等电路故障仿真关键技术及其解决途径,阐述了基于工程软件CARMES的电路故障仿真和最坏情况分析的实现过程。     

Real-time Reliability Prediction for a Dynamic System Based on the Hidden Degradation Process Identification

This paper introduces a real-time reliability prediction method for a dynamic system which suffers from a hidden degradation process. The hidden degradation process is firstly identified by use of particle filtering based on measurable outputs of the considered dynamic system. Then the system's reliability is predicted according to the model of the degradation path. We analyze the identification algorithm mathematically, and validate the effectiveness of this method through computer simulations of a three-vessel water tank. This real-time reliability prediction method is beneficial to the dynamic system's condition monitoring, and may be further helpful to make a proper predictive maintenance policy for the system.     

通信产品系统可靠性预计和分配

本文主要介绍系统可靠性建模、可靠性分配和预计的一种思路，便于在今后的产品设计过程中加强可靠性系统设计。     

A New Real-Time Reliability Prediction Method for Dynamic Systems Based on On-Line Fault Prediction

While a specific system is in use, its reliability will decrease gradually after the infant mortality period because of the components' degradation, or external attacks. Thus, reliability is a natural characteristic of a system's health, and can be used for condition monitoring & predictive maintenance. This paper introduces a new real-time reliability prediction method for dynamic systems which incorporates an on-line fault prediction algorithm. The factors that may reduce a system's reliability are modeled as an additive fault input to the system, and the fault is assumed to be varying linearly with time, approximately. The time-varying fault is roughly estimated based on a modified particle filtering algorithm at first. Then, as a time series, the fault estimate sequence is smoothed, and predicted by an exponential smoothing method. Mathematical analysis shows that the effects of the system, and measurement noises on the fault estimates are greatly reduced by exponential smoothing, which indicates that the comparatively high accuracy of the fault estimates & predictions is guaranteed. Based on the particle filtering & fault prediction results, the whole system's predictive reliability is computed through a Monte Carlo simulation strategy. The effectiveness of the proposed real-time reliability prediction method is validated by a computer simulation of a three-vessel water tank system.     

一种基于工艺模拟的MEMS断裂可靠度预测方法

提出了基于工艺模拟的断裂失效概率计算方法,充分考虑了非理想形貌对失效概率的影响,使得预测结果更加准确.并利用APDL语言对ANSYS进行二次封装,采用VC++开发了可靠度计算程序,使得整个计算过程简便、高效.