A maintenance planning and business case development model for the application of prognostics and health management (PHM) to electronic systems

This paper presents a model that enables the optimal interpretation of prognostics and health management (PHM) results for electronic systems. In this context, optimal interpretation of PHM results means translating PHM information into maintenance policies and decisions that minimize life cycle costs, or maximize availability or some other utility function. The electronics PHM problem is characterized by imperfect and partial monitoring, and a random/overstress failure component must be considered in the decision process. Given that the forecasting ability of PHM is subject to uncertainties in the sensor data collected, the failure and damage accumulation models applied, the material dimensions and properties used in the models, the decision model in this paper addresses how PHM results can best be interpreted to provide value to the system maintainer. The result of this model is a methodology for determining an optimal safety margin and prognostic distance for various PHM approaches in single and multiple socket systems where the LRU’s in the various sockets that make up a system can incorporate different PHM approaches (or have no PHM structures at all).The discrete event simulation model described in this paper provides the information needed to construct a business case showing the application-specific usefulness for various PHM approaches including health monitoring (HM) and life consumption monitoring (LCM) for electronic systems. An example business case analysis for a single socket system is provided.     

集成电路失效机理分析及其PHM技术实现

集成电路的可靠性问题随着制造工艺尺寸的缩小与集成度的增加而变得越来越重要,开展针对集成电路的失效物理为基础的故障预测与健康管理技术,用于预测和评估集成电路产品在实际环境中的可靠性,已成为当今研究的热点。通过阐述集成电路的失效机理,介绍了集成电路目前故障预测与健康管理的基本方法。针对关键失效机理的基于预警单元法的PHM技术方案,提出了对电迁移失效的监控原理、监控方法,通过设计电迁移预警电路,验证了该PHM技术的可行性。     

综合化航空电子系统PHM应用与设计

故障预测与健康管理(PHM)技术应用是保障电子系统任务完成成功率的重要手段和方法。对航空电子系统的PHM应用及设计思路进行了探讨,提出了PHM系统功能关系及适合综合化航空电子系统的健康管理体系。对PHM工程实现的主要关键技术及解决方案进行了研究,重点分析了基于测试性模型的多信号增强诊断方法,以及基于马尔科夫和贝叶斯网络的健康评估方法,对最终实现航空电子系统的PHM全面应用具有指导意义。     

电子系统故障预测与健康管理技术研究

简要回顾了故障预测和健康管理的形成过程和发展历史,从主导思想、关键技术、应用层次和对故障响应方式等方面对比了与传统监控测试技术的区别。重点阐述了故障预测和健康管理的基本原理,通过引入系统健康状态分类和系统健康退化进程,提出了基于状态维修思想,分析了基于状态维修与事后维修和定期维修的区别。按照故障预测和健康管理的能力需求...     

Condition assessment and fault prognostics of microelectromechanical systems

Microelectromechanical systems (MEMS) are used in different applications such as automotive, biomedical, aerospace and communication technologies. They create new functionalities and contribute to miniaturize the systems and reduce their costs. However, the reliability of MEMS is one of their major concerns. They suffer from different failure mechanisms which impact their performance, reduce their lifetime and their availability. It is then necessary to monitor their behavior and assess their health state to take appropriate decision such as control reconfiguration and maintenance. These tasks can be done by using Prognostic and Health Management (PHM) approaches. This paper addresses a condition assessment and fault prognostic method for MEMS. The paper starts with a short review about MEMS and presents some challenges identified and which need to be raised to implement PHM methods. The purpose is to highlight the intrinsic constraints of MEMS from PHM point of view. The proposed method is based on a global model combining both nominal behavior model and degradation model to assess the health state of MEMS and predict their remaining useful life. The method is applied on a microgripper, with different degradation models, to show its effectiveness.     

Towards prognostics and health monitoring: The potential of fault detection by piezoresistive silicon stress sensor

A piezoresistive silicon based stress sensor has been demonstrated successfully as an effective tool to monitor the stresses inside electronic packages during various production processes. More recently, the sensor has been evaluated as a sensor for Prognostics and Health Monitoring (PHM) systems. This paper presents a systematic approach that evaluates its performance from the perspective of failure mode detection. A detailed Finite Element method (FEM) model of existing test vehicles is created. The test vehicle consists of six DPAK (Discrete Package) power packages and three stress sensors. The results of simulation are verified by the signals obtained from the stress sensor as well as the supplementary warpage measurements. After inserting various failure modes into the model, statistical pattern recognition algorithms are implemented for fault detection and classification. The proposed technique can identify detectable failures during reliability testing by utilizing the database of stress sensor responses for healthy and unhealthy state. Thus, the results establish a baseline for the applicability of the piezoresistive stress sensor for an on-line monitoring PHM methodology.     

Life cycle cost impact of using prognostic health management (PHM) for helicopter avionics

Case studies were conducted using a stochastic model to predict the life cycle cost impact associated with the application of prognostic health management (PHM) to helicopter avionics. The life cycle costs of systems that assumed unscheduled maintenance and fixed-interval scheduled maintenance were compared to the costs of precursor-to-failure and life consumption monitoring PHM approaches, and the optimal safety margins and prognostic distances were determined.     

雷达预测与健康管理系统设计

将故障预测与健康管理(PHM)技术引入雷达系统,可极大地提高雷达的任务可靠性和使用可用度。在回顾PHM国内外发展现状和综合分析雷达PHM技术的基础上,建立了雷达系统的PHM架构,实现故障隔离、健康评估、寿命预测和维修决策功能,提炼出存在的技术难点;并以某型雷达应用中的设计为案例进行分析,验证系统可行性和设计效能,可为PHM技术在雷达中的推广应用提供参考。     

A Methodology for Determining the Return on Investment Associated With Prognostics and Health Management

Prognostics and Health Management (PHM) provides opportunities for lowering sustainment costs, improving maintenance decision-making, and providing product usage feedback into the product design and validation process. However, support for PHM is predicated on the articulation of clear business cases that quantify the expected cost and benefits of its implementation. The realization of PHM requires implementation at different levels of scale, and complexity. The maturity, robustness, and applicability of the underlying predictive algorithms impact the overall efficacy of PHM within an enterprise. The utility of PHM to inform decision-makers within tight scheduling constraints, and under different operational profiles likewise affects the cost avoidance that can be realized. This paper discusses the calculation of Return on Investment (ROI) for PHM activities, and presents a study conducted using a stochastic discrete event simulation model to determine the potential ROI offered by electronics PHM. The case study of a multifunctional display in a Boeing 737 compares the life cycle costs of a system employing unscheduled maintenance to the same system using a precursor to failure PHM approach.      

Nvidia’s GPU failures: A case for prognostics and health management

Prognostics and health management (PHM) is an enabling discipline consisting of technologies and methods to assess the reliability of a system in its actual life cycle conditions to determine the advent of failure and mitigate system risks. This paper presents a case study of a failure that had a significant economic impact on the computer industry and its customers, and then discusses how PHM implementation could have resulted in a dramatic difference in the outcome.     

VDMOS器件损伤的DC/DC转换器辐射预兆单元设计

文中应用预警和健全管理(PHM)方法,在深入研究了辐射导致VDMOS器件和DC/DC转换器性能退化之间关系的基础上,设计了基于VDMOS器件损伤的DC/DC转换器辐射预兆单元.经过仿真证实了所设计的预兆单元可以提前报警.     

Prognostics of Analog Filters Based on Particle Filters Using Frequency Features

Analog circuits play an important role in ensuring the availability of electronic systems. Unexpected circuit failures can lead to severe economic implications, and hence, prevention of circuit failures is imperative and highly desired. However, few methods have been suggested for predicting the remaining time till circuit failure. To address this challenge, a novel method for predicting the remaining useful performance (RUP) of analog filters is proposed. By analyzing the circuit’s response to a sweep signal, frequency features such as the center frequency, the lower pass-band limit, the upper pass-band limit, and the maximum frequency response, are extracted. Based on the extracted features, a fault indicator (FI) monitoring the degradation trend of the analog filters is developed for failure prognosis. Moreover, a model is developed based on the degradation trend exhibited by the FI. Particle filters approach is applied to model adaption and RUP prediction. Case studies demonstrating this approach are presented. The studies’ results show that (1) the proposed FI based on the frequency features can well characterize the degradation trend of the analog filters; and (2) the proposed prognostic approach can predict the RUP of analog filters with small error.     

PHM技术在综合航空电子系统中的应用

从某种角度上说,PHM技术并不是本世纪的新技术与新概念.PHM技术说到底是对监测检查系统的升华与独立,这是随着综合航空系统电子系统发展所产生的必然,也是未来航空电子系统中的重点.PHM技术也是我国军事航空中的重点研发项目,对其在综合航空电子系统中的应用的分析,有着重要意义.     

Rational Design of Polymeric Hybrid Micelles with Highly Tunable Properties to Co‐Deliver MicroRNA‐34a and Vismodegib for Melanoma Therapy

A polymeric hybrid micelle (PHM) system with highly tunable properties is reported to co‐deliver small molecule and nucleic acid drugs for cancer therapy; this system is structurally simple and easy‐to‐fabricate. The PHM consists of two amphiphilic diblock copolymers, polycaprolactone‐polyethylenimine (PCL‐PEI) and polycaprolactone‐polyethyleneglycol (PCL‐PEG). PHMs are rationally designed with different physicochemical properties by simply adjusting the ratio of the two diblock copolymers and the near neutral PHM‐2 containing a low ratio of PCL‐PEI achieves the optimal balance between high tumor distribution and subsequent cellular uptake after intravenous injection. Encapsulating Hedgehog (Hh) pathway inhibitor vismodegib (VIS) and microRNA‐34a (miR‐34a) into PHM‐2 generates the VIS/PHM‐2/34a co‐delivery system. VIS/PHM‐2/34a shows synergistic anticancer efficacy in murine B16F10‐CD44⁺ cells, a highly metastatic tumor model of melanoma. VIS/PHM‐2/34a synergistically attenuates the expression of CD44, a vital receptor indicating the metastasis of melanoma. Intriguingly, inhibiting Hh pathway by VIS is accompanied by downregulation of CD44 expression, revealing that Hh signaling might be an upstream regulator of CD44 expression in melanoma. Thus, co‐delivery of miR‐34a and VIS demonstrates great potential in cancer therapy, and PHM offers a structurally simple and highly tunable platform for the co‐delivery of small molecule and nucleic acid drugs in tumor combination therapy.     

A prognostics and health management roadmap for information and electronics-rich systems

Prognostics and systems health management (PHM) is an enabling discipline of technologies and methods with the potential of solving reliability problems that have been manifested due to complexities in design, manufacturing, environmental and operational use conditions, and maintenance. Over the past decade, research has been conducted in PHM of information and electronics-rich systems as a means to provide advance warnings of failure, enable forecasted maintenance, improve system qualification, extend system life, and diagnose intermittent failures that can lead to field failure returns exhibiting no-fault-found symptoms.This paper presents an assessment of the state of practice in prognostics and health management of information and electronics-rich systems. While there are two general methods of performing PHM—model-based and data-driven methods—these methods by themselves have some key disadvantages. This paper presents a fusion prognostics approach, which combines or “fuses together” the model-based and data-driven approaches, to enable markedly better prognosis of remaining useful life. A case study of a printed circuit card assembly is given in order to illustrate the implementation of the fusion approach to prognostics.     

振动载荷下面向电子设备PHM的板级封装潜在故障分析方法

面向电子设备故障预测与健康管理（Prognostics and Health Management,PHM）,基于自适应谱峭度与核概率距离聚类提出一种振动载荷下板级封装潜在故障特征提取与模式辨识方法。首先,基于最大谱峭度原则利用经验模态分解的方法对电子组件的应变响应数据进行滤波,计算并重构包含潜在故障信息的包络谱形成故障征兆向量;其次,应用高斯径向基核函数概率距离方法,将非线性故障征兆数据映射到高维Hilbert空间,对其进行聚类分析形成表征板级封装健康状态与各故障模式的类中心;最后,根据实时监测的板级封装的包络谱数据计算与各中心的概率距离,判断其所属的状态从而实现对封装故障模式的早期辨识。通过试验分析,该方法可以有效辨识与预测板级封装即将发生的故障模式,为实现电子设备PHM提供了一种新式的思路与手段。     

Economic design of the mean prognostic distance for canary-equipped electronic systems

Canaries are a type of early warning device that can be embedded or mounted on electronic systems to issue a pre-failure warning to the host system. A canary is designed to fail faster than the host system. The distance from the time of canary failure to host system failure is called the prognostic distance of the canary. This distance is clearly random depending on the design and operating characteristics of each particular canary and host system, so in practice we often refer to the mean prognostic distance as the measure of prognostic distance. The mean prognostic distance is often determined during the design stage of the canary and the system without taking into account the cost associated with system failure. Clearly, if the consequence of system failure is severe, then the mean prognostic distance should be longer. This paper introduces an economic design for the mean prognostic distance in a canary-equipped system from the perspective of an economic analysis. We establish the necessary conditions for such an economic-based mean prognostic distance to exist and demonstrate it through numerical examples.     

OTHR短CIT条件下自适应舰船目标检测方案

针对在短相干积累时间（CIT）条件下,天波超视距雷达（OTHR）的多普勒频率分辨力和相干积累处理增益降低,导致对低可探测大中型舰船目标检测性能下降的问题,提出一种综合自适应海杂波抑制、重构并检测舰船目标信号的PHM方案。该方案首先利用峰值信噪比（PSNR）-高阶奇异值分解（HOSVD）算法进行自适应海杂波抑制,使信号稀疏化并减少后续检测环节中的虚警;然后利用改进的正交匹配追踪（MOMP）算法进行重构和检测舰船目标信号,改善对目标的检测性能,并提升检测结果中舰船目标的多普勒频率准确度。仿真分析和实测数据处理结果验证了PHM方案的有效性。      

Design for system reliability in personal radio signaling

Innovative techniques and attention to frequently-ignored factors have been combined in a new personal radio signaling system. Accessed by means of Touch-Tone^®service, customer dialing errors are effectively controlled through the use of self-checking numbers, eliminating a common cause of missed or false signals. A multiplicity of radio transmitters are arranged to provide adequate building penetration for the entire service area. Simultaneous transmitter operation and low speed, digital receivers work together to make use of multipath radio propagation. Redundancy of equipment and terminal functions assure that electronic failures result in minimal impairment of service. Combining all of the above design features has resulted in a service that is significantly more reliable than that which is provided by systems of earlier design.     

航空电子设备健康管理系统的设计与实现

针对航空电子设备的健康管理系统,对健康管理系统的基本开发流程进行了研究,完成了健康管理系统软件的功能架构设计.最后,以通用信息处理计算机为例,详细说明健康管理系统软件的具体实现过程.其设计与实现方法可推广应用到其他机载设备上.