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A novel approach for flip chip inspection based on improved SDELM and vibration signals

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Science China(Technological Sciences) 2022年第5期65卷 1087-1097页

作者： SU Lei ZHANG SiYu JI Yong WANG Gang MING XueFei GU JieFei LI Ke pecht michael Jiangsu Key Laboratory of Advanced Food Manufacturing Equipment and Technology School of Mechanical EngineeringJiangnan UniversityWuxi214122China The 58th Research Institute of China Electronics Technology Group Corporation Wuxi214000China Center for Advanced Life Cycle Engineering University of MarylandCollege ParkMD20742USA

This paper proposes a novel nondestructive diagnostic method for flip chips based on an improved semi-supervised deep extreme learning machine(ISDELM)and vibration ***,an ultrasonic transducer is used to generate and focus ultrasounds on the surface of the flip chip to excite it,and a laser scanning vibrometer is applied to acquire the chip’s vibration ***,an extreme learning machine-autoencoder(ELM-AE)structure is adopted to extract features from the original vibration signals layer by ***,the study proposes integrating the ELM with sparsity neighboring reconstruction to diagnose defects based on unlabeled and labeled *** ISDELM algorithm is applied to experimental vibration data of flip chips and compared with several other algorithms,such as semi-supervised ELM(SS-ELM),deep ELM,stacked autoencoder,convolutional neural network,and ordinary *** results show that the proposed method is superior to the several currently available algorithms in terms of accuracy and stability.

关键词： flip chip nondestructive diagnosis improved semi-supervised deep extreme learning machine vibration signal

Opportunistic maintenance for multi-component systems considering structural dependence and economic dependence

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Journal of Systems Engineering and Electronics 2015年第3期26卷 493-501页

作者： Junbao Geng michael Azarian michael pecht College of Power Engineering Naval University of Engineering Center for Advanced Life Cycle Engineering University of Maryland

Although opportunistic maintenance strategies are widely used for multi-component systems, all opportunistic mainte- nance strategies only consider economic dependence and do not take structural dependence into account. An opportunistic main- tenance strategy is presented for a multi-component system that considers both structural dependence and economic dependence. The cost relation and time relation among components based on structural dependence are developed. The maintenance strategy for each component of a multi-component system involves one of five maintenance actions, namely, no-maintenance, a minimal maintenance action, an imperfect maintenance action, a perfect maintenance action, and a replacement action. The maintenance action is determined by the virtual age of the component, the life expectancy of the component, and the age threshold values. Monte Carlo simulation is designed to obtain the optimal oppor- tunistic maintenance strategy of the system over its lifetime. The simulation result reveals that the minimum maintenance cost with a strategy that considers structural dependence is less than that with a strategy that does not consider structural dependence. The availability with a strategy that considers structural dependence is greater than that with a strategy that does not consider structural dependence under the same conditions.

关键词： opportunistic maintenance multi-component system,structural dependence Monte Carlo simulation maintenance cost.

Data-driven reliability analysis of Boeing 787 Dreamliner

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Chinese Journal of Aeronautics 2020年第7期33卷 1969-1979页

作者： Guru PANDIAN michael pecht Enrico ZIO Melinda HODKIEWICZ Center for Advanced Life Cycle Engineering(CALCE) University of MarylandCollege ParkMD 20742USA Department of Energy Politecnico di MilanoItaly Faculty of Engineering and Mathematical Sciences University of Western AustraliaPerthWA 6009Australia

The Boeing 787 Dreamliner,launched in 2011,was presented as a game changer in air *** the aim of producing an efficient,mid-size,wide-body plane,Boeing initiated innovations in product and process design,supply chain operation,and risk ***,there were reliability issues from the start,and the plane was grounded by the *** Aviation Administration(FAA)in 2013,due to safety problems associated with Li-ion battery *** paper chronicles events associated with the aircraft’s initial reliability *** manufacturing,supply chain,and organizational factors that contributed to these problems are assessed based on FAA *** and lessons learned are provided for the benefit of engineers and managers who will be engaged in future complex systems development.

关键词： Boeing 787 Dispatch reliability Dreamliner Lithium-ion battery Reliability Reliability growth

A critique of reliability prediction techniques for avionics applications

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Chinese Journal of Aeronautics 2018年第1期31卷 10-20页

作者： Guru Prasad PANDIAN Diganta DAS Chuan LI Enrico ZIO michael pecht Center for Advanced Life Cycle Engineering University of MarylandCollege Park National Research Base of Intelligent Manufacturing Service Chongqing Technology and Business University Chaire System Science and the Energy Challenge-Fondation Electricite’de France Centrale Supelec Department of Energy Politecnico di Milano

Avionics （aeronautics and aerospace） industries must rely on components and systems of demonstrated high reliability. For this, handbook-based methods have been traditionally used to design for reliability, develop test plans, and define maintenance requirements and sustainment logistics, However, these methods have been criticized as flawed and leading to inaccurate and mis- leading results. In its recent report on enhancing defense system reliability, the U.S. National Academy of Sciences has recently discredited these methods, judging the Military Handbook （MIL- HDBK-217） and its progeny as invalid and inaccurate. This paper discusses the issues that arise with the use of handbook-based methods in commercial and military avionics applications. Alter- native approaches to reliability design （and its demonstration） are also discussed, including similarity analysis, testing, physics-of-failure, and data analytics for prognostics and systems health management.

关键词： Avionics reliability Handbook-based methods MIL-HDBK-217 Physics of failure Prognostics and health management

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浸银电路板蔓延腐蚀评估方法

电工技术学报 2011年第2期26卷 44-49页

作者：周怡琳 michael pecht 北京邮电大学自动化学院北京100876 美国马里兰大学CALCE电子产品和系统中心美国20742

讨论了高硫环境中电路板浸银表面的蔓延腐蚀失效问题。发现焊盘与阻焊膜之间的相对位置关系影响了浸银层的覆盖程度,导致枝状腐蚀物的生成、蔓延长度及主要成分的不同。探讨了采用含硫粘土作为腐蚀源,驱动电路板浸银焊盘蔓延腐蚀的模拟... 详细信息

讨论了高硫环境中电路板浸银表面的蔓延腐蚀失效问题。发现焊盘与阻焊膜之间的相对位置关系影响了浸银层的覆盖程度,导致枝状腐蚀物的生成、蔓延长度及主要成分的不同。探讨了采用含硫粘土作为腐蚀源,驱动电路板浸银焊盘蔓延腐蚀的模拟实验方法。并采用两参数威布尔分布统计蔓延腐蚀物的长度,以特征长度定量评估浸银电路板抗蔓延腐蚀能力。分别研究了腐蚀时间、加热粘土次数和增加相对湿度对含硫粘土模拟方法的影响。提出了采用含硫粘土评估浸银电路板抗蔓延腐蚀的一般方法和对较恶劣工业环境的模拟方法。

关键词：浸银蔓延腐蚀硫化评估

An improved empirical wavelet transform method for rolling bearing fault diagnosis

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Science China(Technological Sciences) 2020年第11期63卷 2231-2240页

作者： HUANG HaiRun LI Ke SU WenSheng BAI JianYi XUE ZhiGang ZHOU Lang SU Lei pecht michael Jiangsu Key Laboratory of Advanced Food Manufacturing Equipment and Technology School of Mechanical EngineeringJiangnan UniversityWuxi 214122China Jiangsu Province Special Equipment Safety Supervision Inspection Institute Wuxi 214071China HUST-Wuxi Research Institute Wuxi 214071China State Key Laboratory of Digital Manufacturing Equipment and Technology Huazhong University of Science and TechnologyWuhan 430074China Center for Advanced Life Cycle Engineering University of MarylandCollege Park MD 20742USA

Empirical wavelet transform(EWT)based on the scale space method has been widely used in rolling bearing fault ***,using the scale space method to divide the frequency band,the redundant components can easily be separated,causing the band to rupture and making it difficult to extract rolling bearing fault characteristic frequency *** paper develops a method for optimizing the frequency band region based on the frequency domain feature parameter *** frequency domain feature parameter set includes two characteristic parameters:mean and *** adaptively dividing the frequency band by the scale space method,the mean and variance of each band are ***-bands with mean and variance less than the main frequency band are combined with surrounding bands for subsequent *** adaptive empirical wavelet filter on each frequency band is established to obtain the corresponding empirical *** margin factor sensitive to the shock pulse signal is introduced into the screening of empirical *** empirical mode with the largest margin factor is selected to envelope spectrum *** and experiment data show this method avoids over-segmentation and redundancy and can extract the fault characteristic frequency easier compared with only scale space methods.

关键词： fault diagnosis empirical wavelet transform scale space method feature parameter margin factor

Joint Estimation of Inconsistency and State of Health for Series Battery Packs

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Automotive Innovation 2021年第1期4卷 103-116页

作者： Yunhong Che Aoife Foley Moustafa El‑Gindy Xianke Lin Xiaosong Hu michael pecht Department of Automotive Engineering Chongqing UniversityChongqing 400044China School of Mechanical&Aerospace Engineering Queen’s UniversityBelfast BT95AHUK School of Engineering Trinity College DublinUniversity of DublinCollege GreenDublin 2Ireland Department of Automotive Mechanical and Manufacturing EngineeringOntario Tech University2000 Simcoe St NOshawaON L1G 0C5Canada Center for Advanced Life Cycle Engineering University of MarylandCollege ParkMD 20742USA

Battery packs are applied in various areas(e.g.,electric vehicles,energy storage,space,mining,etc.),which requires the state of health(SOH)to be accurately ***,also known as cell variation,is considered a significant evaluation index that greatly affects the degradation of battery *** paper proposes a novel joint inconsistency and SOH estimation method under cycling,which fills the gap of joint estimation based on the fast-charging process for electric ***,fifteen features are extracted from current change points during the partial charging ***,a joint estimation system is designed,where fusion weights are obtained by the analytic hierarchy process and multi-scale sample entropy to evaluate inconsistency.A wrapper is used to select the optimal feature subset,and Gaussian process regression is implemented to estimate the ***,the estimation performance is assessed by the test *** results show that the inconsistency evaluation can reflect the aging conditions,and the inconsistency does affect the aging *** wrapper selection method improves the accuracy of SOH estimation by about 75.8%compared to the traditional filter method when only 10%of data is used for model *** maximum absolute error and root mean square error are 2.58%and 0.93%,respectively.

关键词： Battery pack inconsistency State of health Fusion weight Feature selection GPR

故障预测与健康管理(PHM)技术的现状与发展

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航空学报 2005年第5期26卷 626-632页

作者：曾声奎 michael G.pecht 吴际北京航空航天大学可靠性工程研究所北京100083 美国马里兰大学CALCE电子产品与系统中心马里兰20742

结合故障预测与健康管理(PHM)的技术发展过程,阐述了PHM的应用价值。论述了PHM技术系统级应用问题,提出了故障诊断与预测的人-机-环完整性认知模型,并依此对蓬勃发展的故障诊断与故障预测技术进行了分类与综合分析,给出了PHM技术的发展... 详细信息

结合故障预测与健康管理(PHM)的技术发展过程,阐述了PHM的应用价值。论述了PHM技术系统级应用问题,提出了故障诊断与预测的人-机-环完整性认知模型,并依此对蓬勃发展的故障诊断与故障预测技术进行了分类与综合分析,给出了PHM技术的发展图像。针对故障诊断与预测的不确定性特征,对故障诊断与预测技术的性能要求、定量评价与验证方法进行了分析。最后,以PHM技术的工程应用为线索,提出了PHM技术发展中的几个问题。

关键词：故障预测故障诊断故障预测与健康管理

不同开路电压松弛时间下基于等效电路解构的锂离子电池荷电状态估计（英文）

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2017年第4期18卷 256-267页

作者： Xi-ming CHENG Li-guang YAO michael pecht Collaborative Innovation Center for Electric Vehicles in Beijing National Engineering Laboratory for Electric VehiclesDepartment of Vehicular Engineering Beijing Institute of Technology Center of Advanced Life Cycle Engineering University of Maryland

目的:开路电压是基于模型的电池荷电状态估计的必要参数,其测试耗时大、效率低。本文旨在测试各种电压松弛时间的荷电状态-开路电压关系,研究其对开路电压法和等效电路模型的荷电状态估计准确度的影响,提高开路电压测试效率。创新点:1.... 详细信息

目的:开路电压是基于模型的电池荷电状态估计的必要参数,其测试耗时大、效率低。本文旨在测试各种电压松弛时间的荷电状态-开路电压关系,研究其对开路电压法和等效电路模型的荷电状态估计准确度的影响,提高开路电压测试效率。创新点:1.通过电路解构方法,将二阶阻容电路分解为简单路,运用二阶段递推最小二乘法辨识电路模型的参数;2.基于递推最小二乘法和卡尔曼滤波算法,建立电路参数辨识和荷电状态估计的的联合自适应算法,研究电池电压松弛时间对基于等效电路模型的荷电状态估计的影响。方法:1.通过电路解构技术和理论推导,构建辨识二阶阻容等效电路参数的二阶段递推最小二乘法辨识方法(图2和公式(4)^(9));2.将二阶段递推最小二乘法和扩展卡尔曼滤波器集成,建立适应工况变化的电池模型参数辨识和状态估计的联合算法(图3);3.通过电池测试,建立多温度和多电压松弛时间的荷电状态与开路电压的关系,驱动自适应联合算法,获得既保证荷电状态估计准确度,又缩短开路电压测试时间的电压松弛时间。结论:1.二阶段递推最小二乘法既能简化矩阵计算,又能够保证电路参数的辨识非负性;2.联合自适应算法能够适应工况变化辨识模型参数和估计荷电状态;3.联合自适应算法的结果表明,5 min的电压松弛时间既能保证荷电状态估计性能,又能极大地提高开路电压测试效率。

关键词：锂离子电池开路电压荷电状态递推最小二乘法扩展卡尔曼滤波器