基于模糊评价方法的新产品开发过程可靠性度量

针对新产品开发（new product development,NPD）过程难以获得所需的可靠性数据的问题,利用模糊打分法获取所需的可靠性数据。基于IDEF0（Integrated Definition for Function Modeling）建模的基础上,以模糊评价法为工具,构造了基于专家经验的模糊影响矩阵,以“输出”的质量作为过程的可靠性,在此基础上对新产品开发过程的可靠性作出评价。仿真结果表明本文提出的方法不仅可以有效地对过程可靠性作出评价,可以从定量的角度确定影响新产品开发过程可靠性的关键因素。      

滚动轴承的振动性能退化过程与保持可靠性研究

为了分析滚动轴承的振动性能退化过程与保持可靠性之间的关系,提出一种基于最大熵法和相似度法的滚动轴承振动性能退化模型,并对滚动轴承的退化过程进行评估;然后基于最大熵法和泊松过程建立滚动轴承振动性能保持可靠性模型;最后基于灰关系理论对滚动轴承的性能退化序列和保持可靠性序列进行分析。实验结果表明,所提出的滚动轴承振动性能退化模型能够有效地识别滚动轴承的退化状态,并且滚动轴承振动性能保持可靠性的演变历程与振动性能退化过程之间有明显的灰关系,可信水平均达到80%以上。     

航天电连接器加速性能退化试验可行性研究

为解决高可靠长寿命的航天电连接器即使进行加速寿命试验也难以获得失效数据的问题,对电连接器失效模式以及长期贮存下接触性能变化结果进行分析,表明电连接器性能退化存在可能性,并根据长期贮存下试验数据的验证,得出电连接器性能具有退化特性.通过温度加速应力下电连接器接触性能数据的分析,得出其性能退化具有加速性,还具有一定的加速退化规律,这为采用加速性能退化试验对航天电连接器进行可靠性评估提供了依据.     

基于ARMA模型的加速退化试验可靠性评估

有限时间内很难获得大量电子产品的失效数据,传统可靠性评估方法存在一定局限。在分析传统加速退化试验可靠性评估的基础之上,提出利用时间序列对产品加速退化过程描述的方法,使用自回归滑动平均混合(ARMA)模型对退化数据进行建模,通过参数估计得到其退化规律的表达式,从而外推出其失效寿命,进而利用极大似然估计理论进行可靠性评估。最后以某电源电路板加速退化试验数据为例,分时间序列建模和可靠性评估两大步骤,分别对95℃、105℃、115℃下加速退化试验数据进行分析处理,得出可靠性评估结果,验证该方法的有效性和实用性。     

基于电子产品板级加速退化数据的可靠性分析

以某24 V-2 A稳压电源板在80 C,100 C,120 C下进行恒加加速退化试验为例,观测到电源板输出电压随温度变化的退化过程,由B-S模型采用回归方法进行了可靠性统计推断,并与其它评估结果比较.结论表明,基于加速性能退化数据进行板级电子产品可靠性评估方法可行、结果可信,且更节约试验成本和时间,无继往数据和无失效数据情况下仍能适用.     

基于伪寿命分布的电主轴极小子样可靠性研究

在分析和研究了电主轴性能退化失效机理的前提下,选取合适的性能退化特征量,在此条件下设计电主轴可靠性实验方案,并在该方案的指导下进行电主轴可靠性实验。在研究了基于伪寿命分布的退化数据可靠性评估方法的基本原理基础上,应用该方法结合电主轴实验样本的可靠性实验数据,综合虚拟增广样本法对其可靠性进行评估。最终获得失效分布函数、分布密度函数及其曲线,以及一系列可靠性指标,包括可靠度函数及其曲线、失效率函数及其曲线、平均寿命及部分可靠寿命等。     

性能退化量分布LED可靠性评估

针对LED可靠性评估的方法大部分均基于样品伪寿命这一现象,提出基于退化量分布的LED可靠性评估方法。先依据指数模型预测后续时刻的退化量,再通过β分布统示法求出各时刻的累积失效概率,然后根据加速模型确定常应力下LED的可靠度函数。以国内某型LED灯具为实验对象,求出该型灯具寿命估计值为77100h,验证方法的实用性、有效性。     

数据驱动的多元性能退化特征产品可靠性建模

为解决多元性能退化特征产品可靠性建模困难,提出了一种通用的可靠性建模方法。首先,基于产品多元退化数据,运用ReliefF算法提取产品关键退化特征;然后,通过满窗宽矩阵的多元核密度方法,估计产品在各检测时刻的可靠度;最后,利用各检测时刻可靠度估计结果,拟合产品寿命分布。案例结果表明,该方法能够克服传统参数方法需对产品退化特征量分布作出具体假设的局限,并且能够获得比文献方法精度更高的产品可靠度估计值。另外,该方法可以为后续产品的可靠性试验减少检测工作量,节约试验成本。     

舰船总体性能可靠性建模方法研究

分析了舰船总体性能可靠性问题的产生原因，将其分为2类．对于舰载设备本身存在可靠性问题而造成的，以航速可靠性为例，在舰船总体可靠性的背号下，借助相关数学工具进行了建模方法分析；对于外界随机因素影响而造成的，如横稳性的可靠性问题，则从分析外界随机因素与船体设计参数之间关系入手．初步建立了一套研究舰船总体性能可靠性问题的建模方法．实例计算表明，将所建模型用于分析舰船总体性能比常规方法具有明显的优越性．     

退化串联可修系统瞬态可靠性分析

可修串联系统是一类经典的可靠性模型,在实际工程中较为常见．为满足工程实际需求,所研究的系统由2个部件和1个维修工组成．假设工作时间、维修时间和部件更换时间均服从指数分布,在维修之后系统不能修复如新．系统采用部件故障N次之后将被更新的维修策略．在这些假设下利用几何过程和马尔科夫过程对系统进行建模,再利用半马尔科夫过程和数值积分方法给出系统瞬态可用度和（0,t］时间内故障次数的计算公式．最后给出算例并应用Monte Carlo方法对所得公式进行验证．为进一步研究复杂机械系统的可靠性提供了理论基础．     

Reliability analysis of electronic devices with multiple competing failure modes involving performance aging degradation

This paper presents an extension of reliability analysis of electronic devices with multiple competing failure modes involving performance aging degradation. The probability that a product fails on a specific mode is derived. Using this probability, the dominant failure mode on the product can be predicted. A practical example is presented to analyze an electronic device with two kinds of major failure modes–solder/Cu pad interface fracture (a catastrophic failure) and light intensity degradation (a degradation failure). Reliability modeling of an individual failure mode and device reliability analysis is presented and results are discussed. Copyright © 2003 John Wiley & Sons, Ltd.     

小波包变换和隐马尔可夫模型在轴承性能退化评估中的应用

轴承是旋转机械中的关键部件,有效地对其进行性能退化评估对指导设备维护、防止设备意外失效有非常重要的意义。本文提出了一种基于小波包变换和隐马尔可夫模型（HMM）的轴承性能退化评估方法。该方法使用小波包变换对轴承振动信号进行分析,并提取节点能量及其总能量作为特征,仅使用正常状态下的数据训练HMM,建立性能退化评估模型,然后使用该模型对轴承的退化程度进行定量评估。最后,通过对轴承加速疲劳寿命试验的研究,验证了所提出的方法的可行性和有效性。     

基于性能衰退评估的轴承寿命状态识别方法研究

针对滚动轴承退化性能难以评估、寿命状态难以识别的难题,提出一种基于性能衰退评估的轴承寿命状态识别新方法,该方法基于卷积自编码器(convolutional autoencoder,CAE)与多维尺度分析(multidimensional scaling,MDS)算法构建轴承性能衰退指标,再根据构建指标和改进卷积神经网络...     

Reliability analysis for accelerated degradation data based on the Wiener process with random effects

On the basis of the principle of degradation mechanism invariance, a Wiener degradation process with random drift parameter is used to model the data collected from the constant stress accelerated degradation test. Small-sample statistical inference method for this model is proposed. On the basis of Fisher's method, a test statistic is proposed to test if there is unit-to-unit variability in the population. For reliability inference, the quantities of interest are the quantile function, the reliability function, and the mean time to failure at the designed stress level. Because it is challenging to obtain exact confidence intervals (CIs) for these quantities, a regression type of model is used to construct pivotal quantities, and we develop generalized confidence intervals (GCIs) procedure for those quantities of interest. Generalized prediction interval for future degradation value at designed stress level is also discussed. A Monte Carlo simulation study is used to demonstrate the benefits of our procedures. Through simulation comparison, it is found that the coverage proportions of the proposed GCIs are better than that of the Wald CIs and GCIs have good properties even when there are only a small number of test samples available. Finally, a real example is used to illustrate the developed procedures.     

Engineering‐driven performance degradation analysis of hydraulic piston pump based on the inverse Gaussian process

As a key aircraft component, hydraulic piston pumps must be developed with high reliability. However, collecting failure time data of such pumps for reliability analysis is a big challenge. To save testing time, performance degradation data obtained from degradation tests can be used for quick reliability estimation of hydraulic piston pumps. This paper proposes an engineering‐driven performance degradation analysis method considering the nature of mechanical wear of hydraulic piston pumps. First, the failure mechanism of a type of hydraulic piston pump is investigated. By taking into account the close relationship between the degradation rate and the failure mechanism, an inverse Gaussian (IG) process model with a variable rate is developed to describe the degradation behavior of the pump. Under this model, a Bayesian statistical method is developed for degradation data analysis. The corresponding procedure for model parameter estimation and reliability evaluation is also presented. The proposed degradation analysis method is illustrated using a real experimental data. The results show that the engineering‐driven approach is quite effective in evaluating the lifetime of the hydraulic piston pump and will improve the overall reliability of aircraft operation in the field.     

Reliability modeling for competing failure processes considering degradation rate variation under cumulative shock

Most systems experience both random shocks (hard failure) and performance degradation (soft failure) during service span, and the dependence of the two competing failure processes has become a key issue. In this study, a novel dependent competing failure processes (DCFPs) model with a varying degradation rate is proposed. The comprehensive impact of random shocks, especially the effect of cumulative shock, is reasonably considered. Specifically, a shock will cause an abrupt degradation damage, and when the cumulative shock reaches a predefined threshold, the degradation rate will change. An analytical reliability solution is derived under the concept of first hitting time (FHT). Besides, a one-step maximum likelihood estimation method is established by constructing a comprehensive likelihood function. Finally, the reasonability of the closed form reliability solution and the feasibility and effectiveness of the proposed DCFPs modeling methodology are demonstrated by a comparative simulation study.     

基于EMD多尺度威布尔分布与HMM的轴承性能退化评估方法

轴承作为旋转机械中的重要部件,对其性能退化状态进行准确评估是开展预测性维护的重要前提。针对现有性能退化指标在鲁棒性和敏感性上的不足,提出一种基于多尺度威布尔分布与隐马尔可夫模型(Hidden Markov model,HMM)的滚动轴承性能退化评估方法。首先,采用经验模态分解(empirical mode decomposition,EMD)对轴承振动信号进行多尺度分解,将轴承振动数据分解到不同尺度的本征模态分量(intrinsic mode function,IMF)中;然后,通过峭度指标选取故障特征信息明显的IMF分量,并对各个IMF分量进行滑动窗口威布尔分布拟合,提取多尺度威布尔形状参数作为性能退化特征;最后,将轴承正常状态下退化特征参数输入隐马尔可夫模型(Hidden Markov model,HMM)进行训练,建立性能退化评估模型,从而实现轴承性能退化评估。试验结果表明,该评估方法可以有效反映轴承的性能退化趋势,与其他相关方法相比,该方法能够及时识别到轴承早期故障,并且具有较强的稳定性。     

Integration method for reliability assessment with multi-source incomplete accelerated degradation testing data

ABSTRACT

During the product life cycle, the lifetime information will be collected at each stage, mainly from different tests at the R&D phase, field usage, and maintenance. To comprehensively conduct reliability assessments, it generally requires the integration of multi-source datasets, even that from similar products. In this article, we considered the scenario that products have been arranged with several accelerated degradation tests (ADT) under different types of accelerated stresses with dependency. The obtained data is called incomplete ADT dataset with incomplete stress conditions which fails the traditional integration method for reliability assessments. A novel method is proposed to accomplish this task through mutually exclusive set (MES) theory. The probability assignments for each dataset are given through the union set of several MESs. Then, the multi-source ADT datasets are integrated with the assigned weights of probabilities. Finally, a simulation study and a real application are given to illustrate the effectiveness of the proposed methodology.     

基于AR模型的Kolmogorov-Smirnov检验性能退化及预测研究

设备性能退化评估是对现有故障诊断技术的全新拓展,它为更有效地实现智能主动维护提供参考,更有利于实现设备的零停机率。开展对设备的性能退化评估研究,还可以实现对设备的性能预测维护功能,大大提高设备运行的可靠性。提出了基于AR预测白噪化的Kolmogorov-Smirnov检验方法,同时实现了滚动轴承的全寿命实验。通过对轴承全寿命实验数据的分析研究,论证了本方法在设备性能退化评估及预测中的研究价值,相对于有效值等传统方法,它不仅能够显著地表现前期的微弱退化状态,而且还能有条件地更早指示设备的异常状态,对于故障预测的研究具有较大的意义。     

基于故障危害度的飞机电源系统可靠性评估

基于故障危害度对飞机电源系统进行可靠性评估,首先建立可靠性评估模型,该模型考虑各故障样本对飞机电源系统供电可靠性危害度影响,将出现的故障按照对电源系统安全、性能、任务及维修等指标的影响程度进行等级分类,从故障的失效机理出发建立相应的分布模型;然后采用分布计算和二次分布等算法进行系统整体可靠性指标评估。应用该模型对飞机电源系统进行了故障统计分析,计算了飞机电源系统的可靠性指标。