Health management based on fusion prognostics for avionics systems

Health management permits the reliability of a system and plays a increasingly important role for achieving efficient system-level maintenance.It has been used for remaining useful life（RUL） prognostics of electronics-rich system including avionics.Prognostics and health management（PHM） have become highly desirable to provide avionics with system level health management.This paper presents a health management and fusion prognostic model for avionics system,combining three baseline prognostic approaches that are model-based,data-driven and knowledge-based approaches,and integrates merits as well as eliminates some limitations of each single approach to achieve fusion prognostics and improved prognostic performance of RUL estimation.A fusion model built upon an optimal linear combination forecast model is then utilized to fuse single prognostic algorithm representing the three baseline approaches correspondingly,and the presented case study shows that the fusion prognostics can provide RUL estimation more accurate and more robust than either algorithm alone.

An Edge-Fog-Cloud Computing-Based Digital Twin Model for Prognostics Health Management of Process Manufacturing Systems

The prognostics health management(PHM)fromthe systematic viewis critical to the healthy continuous operation of processmanufacturing systems(PMS),with different kinds of dynamic interference events.This paper proposes a three leveled digital twinmodel for the systematic PHMof PMSs.The unit-leveled digital twinmodel of each basic device unit of PMSs is constructed based on edge computing,which can provide real-time monitoring and analysis of the device status.The station-leveled digital twin models in the PMSs are designed to optimize and control the process parameters,which are deployed for the manufacturing execution on the fog server.The shop-leveled digital twin maintenancemodel is designed for production planning,which gives production instructions fromthe private industrial cloud server.To cope with the dynamic disturbances of a PMS,a big data-driven framework is proposed to control the three-level digital twin models,which contains indicator prediction,influence evaluation,and decisionmaking.Finally,a case study with a real chemical fiber system is introduced to illustrate the effectiveness of the digital twin model with edge-fog-cloud computing for the systematic PHM of PMSs.The result demonstrates that the three-leveled digital twin model for the systematic PHM in PMSs works well in the system’s respects.

Overview of the Importance of Intelligent Approaches on Machinery Faults Diagnosis and Prediction Based on Prognostic and Health Management/Condition-Based Maintenance

Condition monitoring is increasingly used to anticipate and detect failures of industrial machines.Failures of machines can cause high maintenance or replacement costs.If neglected,it may result in catastrophic accidents leading to production shrinkage.The potential failure would negatively affect the profitability of the company,including production shut down,cost of spare parts,cost of labor,damage of reputation,risk of injury to people and the environment.In recent years,condition-based maintenance( CBM) and prognostic and health management( PHM) are developed and formed a strong connection among science,engineering,computer,reliability,communication,management,etc.Computerized maintenance management systems( CMMS) store a lot of data regarding the fault diagnosis and life prediction of the machinery equipment.It's too necessary to uncover useful knowledge from the huge amount of data.It's vital to find the ways to obtain useful and concise information from these data.This information can be of great influence in the decision making of managers.This article is a review of intelligent approaches in machinery faults diagnosis and prediction based on PHM and CBM.

Battery prognostics and health management for electric vehicles under industry 4.0

Transportation electrification is essential for decarbonizing transport. Currently, lithium-ion batteries are the primary power source for electric vehicles (EVs). However, there is still a significant journey ahead before EVs can establish themselves as the dominant force in the global automotive market. Concerns such as range anxiety, battery aging, and safety issues remain significant challenges.

A Possibilistic Approach for Uncertainty Representation and Propagation in Similarity-Based Prognostic Health Management Solutions

In this paper, a data-driven prognostic model capable to deal with different sources of uncertainty is proposed. The main novelty factor is the application of a mathematical framework, namely a Random Fuzzy Variable (RFV) approach, for the representation and propagation of the different uncertainty sources affecting Prognostic Health Management (PHM) applications: measurement, future and model uncertainty. In this way, it is possible to deal not only with measurement noise and model parameters uncertainty due to the stochastic nature of the degradation process, but also with systematic effects, such as systematic errors in the measurement process, incomplete knowledge of the degradation process, subjective belief about model parameters. Furthermore, the low analytical complexity of the employed prognostic model allows to easily propagate the measurement and parameters uncertainty into the RUL forecast, with no need of extensive Monte Carlo loops, so that low requirements in terms of computation power are needed. The model has been applied to two real application cases, showing high accuracy output, resulting in a potentially effective tool for predictive maintenance in different industrial sectors.

Virtual sample generation for model-based prognostics and health management of on-board high-speed train control system

In view of class imbalance in data-driven modeling for Prognostics and Health Management(PHM),existing classification methods may fail in generating effective fault prediction models for the on-board high-speed train control equipment.A virtual sample generation solution based on Generative Adversarial Network(GAN)is proposed to overcome this shortcoming.Aiming at augmenting the sample classes with the imbalanced data problem,the GAN-based virtual sample generation strategy is embedded into the establishment of fault prediction models.Under the PHM framework of the on-board train control system,the virtual sample generation principle and the detailed procedures are presented.With the enhanced class-balancing mechanism and the designed sample augmentation logic,the PHM scheme of the on-board train control equipment has powerful data condition adaptability and can effectively predict the fault probability and life cycle status.Practical data from a specific type of on-board train control system is employed for the validation of the presented solution.The comparative results indicate that GAN-based sample augmentation is capable of achieving a desirable sample balancing level and enhancing the performance of correspondingly derived fault prediction models for the Condition-based Maintenance(CBM)operations.

Computational Reproducibility Within Prognostics and Health Management

Scientific research frequently involves the use of computational tools and methods.Providing thorough documentation,open-source code,and data–the creation of reproducible computational research(RCR)–helps others understand a researcher’s work.In this study,we investigate the state of reproducible computational research,broadly,and from within the field of prognostics and health management(PHM).In a text mining survey of more than 300 articles,we show that fewer than 1%of PHM researchers make their code and data available to others.To promote the RCR further,our work also highlights several personal benefits for those engaged in the practice.Finally,we introduce an open-source software tool,called PyPHM,to assist PHM researchers in accessing and preprocessing common industrial datasets.

A Certifiable Framework for Health Monitoring and Management

The scope of this paper is to provide an E2 Eperspective of health monitoring and management(HMM)and structural health mornitoring(SHM)as an integrated system element of an integrated system health monitoring and management(ISHM)system.The paper will address two main topics:(1)The importance of a diagnostics and prognostic requirements specification to develop an innovative health monitoring and management system;(2)The certification of a health monitoring and management system aiming at a maintenance credit as an integral part of the maintenance strategies.The development of a maintenance program which is based on combinations of different types of strategies(preventive,condition-based maintenance(CBM)and corrective maintenance…)for different subsystems or components and structures of complex systems like an aircraft to achieve the most optimized solution in terms of availability,cost and safety/certification is a real challenge.The maintenance strategy must satisfy the technical-risk and cost feasibility of the maintenance program.

Dynamically updated digital twin for prognostics and health management:Application in permanent magnet synchronous motor

Current research on Digital Twin(DT)based Prognostics and Health Management(PHM)focuses on establishment of DT through integration of real-time data from various sources to facilitate comprehensive product monitoring and health management.However,there still exist gaps in the seamless integration of DT and PHM,as well as in the development of DT multi-field coupling modeling and its dynamic update mechanism.When the product experiences long-period degradation under load spectrum,it is challenging to describe the dynamic evolution of the health status and degradation progression accurately.In addition,DT update algorithms are difficult to be integrated simultaneously by current methods.This paper proposes an innovative dual loop DT based PHM framework,in which the first loop establishes the basic dynamic DT with multi-filed coupling,and the second loop implements the PHM and the abnormal detection to provide the interaction between the dual loops through updating mechanism.The proposed method pays attention to the internal state changes with degradation and interactive mapping with dynamic parameter updating.Furthermore,the Independence Principle for the abnormal detection is proposed to refine the theory of DT.Events at the first loop focus on accurate modeling of multi-field coupling,while the events at the second loop focus on real-time occurrence of anomalies and the product degradation trend.The interaction and collaboration between different loop models are also discussed.Finally,the Permanent Magnet Synchronous Motor(PMSM)is used to verify the proposed method.The results show that the modeling method proposed can accurately track the lifecycle performance changes of the entity and carry out remaining life prediction and health management effectively.

Large Power Transformer Fault Diagnosis and Prognostic Based on DBNC and D-S Evidence Theory

Power transformer is a core equipment of power system, which undertakes the important functions of power transmission and transformation, and its safe and stable operation has great significance to the normal operation of the whole power system. Due to the complex structure of the transformer, the use of single information for condition-based maintenance (CBM) has certain limitations, with the help of advanced sensor monitoring and information fusion technology, multi-source information is applied to the prognostic and health management (PHM) of power transformer, which is an important way to realize the CBM of power transformer. This paper presents a method which combine deep belief network classifier (DBNC) and D-S evidence theory, and it is applied to the PHM of the large power transformer. The experimental results show that the proposed method has a high correct rate of fault diagnosis for the power transformer with a large number of multi-source data.

An ontological modelling of multi-attribute criticality analysis to guide Prognostics and Health Management program development

Digital technologies are becoming more pervasive and industrial companies are exploiting them to enhance the potentialities related to Prognostics and Health Management(PHM).Indeed,PHM allows to evaluate the health state of the physical assets as well as to predict their future behaviour.To be effective in developing PHM programs,the most critical assets should be identified so to direct modelling efforts.Several techniques could be adopted to evaluate asset criticality;in industrial practice,criticality analysis is amongst the most utilised.Despite the advancement of artificial intelligence for data analysis and predictions,the criticality analysis,which is built upon both quantitative and qualitative data,has not been improved accordingly.It is the goal of this work to propose an ontological formalisation of a multi-attribute criticality analysis in order to i)fix the semantics behind the terms involved in the analysis,ii)standardize and uniform the way criticality analysis is performed,and iii)take advantage of the reasoning capabilities to automatically evaluate asset criticality and associate a suitable maintenance strategy.The developed ontology,called MOCA,is tested in a food company featuring a global footprint.The application shows that MOCA can accomplish the prefixed goals;specifically,high priority assets towards which direct PHM programs are identified.In the long run,ontologies could serve as a unique knowledge base that integrate multiple data and information across facilities in a consistent way.As such,they will enable advanced analytics to take place,allowing to move towards cognitive Cyber Physical Systems that enhance business performance for companies spread worldwide.

Prognostics and health management of alkaline water electrolyzer: Techno-economic analysis considering replacement moment

Recently,considerable attention has been paid to the installation of renewable energy capacity to mitigate global CO_(2) emissions.H_(2) produced using water electrolysis and renewable energy is regarded as a clean energy carrier,generating electricity without CO_(2) emissions,called‘Green H 2’.In this paper,a prognostics and health man-agement model for an alkaline water electrolyzer was proposed to predict the load voltage on the electrolyzer to obtain the state of health information.The prognostics and health management model was developed by training historical operating data via machine learning models,support vector machine and gaussian process regression,showing the root mean square error of 1.28×10^(−3) and 8.03×10^(−6).In addition,a techno-economic analysis was performed for a green H_(2) production system,composed of 1 MW of photovoltaic plant and 1 MW of alkaline water electrolyzer,to provide economic insights and feasibility of the system.A levelized cost of H_(2) of$6.89 kgH_(2)−1 was calculated and the potential to reach the levelized cost of H_(2) from steam methane reforming with carbon capture and storage was shown by considering the learning rate of the photovoltaic module and elec-trolyzer.Finally,the replacement of the alkaline water electrolyzer at around 10 years was preferred to increase the net present value from the green H_(2) production system when capital expenditure and replacement cost are low enough.

Boosting battery state of health estimation based on self-supervised learning

State of health(SoH) estimation plays a key role in smart battery health prognostic and management.However,poor generalization,lack of labeled data,and unused measurements during aging are still major challenges to accurate SoH estimation.Toward this end,this paper proposes a self-supervised learning framework to boost the performance of battery SoH estimation.Different from traditional data-driven methods which rely on a considerable training dataset obtained from numerous battery cells,the proposed method achieves accurate and robust estimations using limited labeled data.A filter-based data preprocessing technique,which enables the extraction of partial capacity-voltage curves under dynamic charging profiles,is applied at first.Unsupervised learning is then used to learn the aging characteristics from the unlabeled data through an auto-encoder-decoder.The learned network parameters are transferred to the downstream SoH estimation task and are fine-tuned with very few sparsely labeled data,which boosts the performance of the estimation framework.The proposed method has been validated under different battery chemistries,formats,operating conditions,and ambient.The estimation accuracy can be guaranteed by using only three labeled data from the initial 20% life cycles,with overall errors less than 1.14% and error distribution of all testing scenarios maintaining less than 4%,and robustness increases with aging.Comparisons with other pure supervised machine learning methods demonstrate the superiority of the proposed method.This simple and data-efficient estimation framework is promising in real-world applications under a variety of scenarios.

Deep neural network based classification of rolling element bearings and health degradation through comprehensive vibration signal analysis

Rolling element bearings are machine components used to allow circular movement and hence deliver forces between components of machines used in diverse areas of industry.The likelihood of failure has the propensity of increasing under prolonged operation and varying working conditions.Hence, the accurate fault severity categorization of bearings is vital in diagnosing faults that arise in rotating machinery.The variability and complexity of the recorded vibration signals pose a great hurdle to distinguishing unique characteristic fault features.In this paper, the efficacy and the leverage of a pre-trained convolutional neural network(CNN) is harnessed in the implementation of a robust fault classification model.In the absence of sufficient data, this method has a high-performance rate.Initially, a modified VGG16 architecture is used to extract discriminating features from new samples and serves as input to a classifier.The raw vibration data are strategically segmented and transformed into two representations which are trained separately and jointly.The proposed approach is carried out on bearing vibration data and shows high-performance results.In addition to successfully implementing a robust fault classification model, a prognostic framework is developed by constructing a health indicator(HI) under varying operating conditions for a given fault condition.

知识图谱技术在预测与健康管理中的应用现状与研究展望

随着预测与健康管理(PHM)技术的不断发展以及设备智能化、信息化程度的不断提高,预测与健康管理的领域知识与日俱增。知识图谱技术因其强大的知识组织、管理、表示能力以及支持的数据/知识驱动相关方法,受到领域内学者广泛关注。面向预测与健康管理领域,对知识图谱的概念、关键技术、领域应用以及挑战与展望进行了综述。首先,介绍了领域知识图谱的定义和组成要素;其次,讨论了领域知识图谱的构建方法,简要归纳了领域内常用的构建方式和技术;然后,结合领域内知识特点,详细介绍了领域内知识图谱的应用情况;最后,分析了与领域融合的知识图谱研究中存在的挑战以及未来的发展方向。综述旨在帮助研究者加深对知识图谱及其在预测与健康管理领域应用的了解,以促进知识图谱在该领域应用中的进一步发展和创新。

装备测试性工程技术现状与新进展

装备测试性工程技术起源于20世纪80年代,是先进测试技术与系统工程紧密结合的产物。该技术经过40余年的发展逐渐成熟,在测试性需求分析与分配、测试性建模与方案优化设计、机内测试(Built⁃In Test,BIT)与自动测试系统(Automatic Test System,ATS)设计、测试性试验与评估等方面形成了较完善的理论体系,并在各型装备中得到了普遍应用,取得了较大的军事和社会效益。今后测试性基础研究和应用探索究竟该如何开展,未来发展方向是怎样的,是亟需深入探讨的问题。在对测试性工程技术的产生背景与需求、概念与内涵、发展历程、关键技术现状与新进展进行剖析的基础上,指出了目前测试性工程技术研究存在的问题和今后研究突破的方向。

融合Transformer的剩余使用寿命预测模型

剩余使用寿命(remaining useful life,RUL)预测对大型设备的故障预测与健康管理十分重要。然而,一些设备监测数据具有维度高、规模大、强耦合、参数时变等非线性特征,这些特征会导致RUL预测的准确性较低。为此引入Transformer解码器,并通过多头注意力机制综合全局信息,提出了一种基于多尺度双向长短期记忆网络和Transformer的神经网络模型,以提高模型预测精度。选取航空发动机作为研究对象,使用各个模型在NASA的C-MPASS数据集上进行对比实验,结果表明,在剩余使用寿命预测方面,该文提出的融合Transformer模型的多尺度双向长短期记忆网络模型在准确率和均方根误差指标上均优于其他对比模型。

大型旋转机组健康管理系统软件通用平台研究

针对大型旋转机组健康管理存在全生命周期数据“整合难”、健康预测评价“量化难”、维修决策“优化难”和系统平台“泛化难”等问题,首先,引入云原生思想,采用容器化技术和微服务架构,设计了大型旋转机组健康管理系统软件开放通用架构;其次,研发了大型旋转机组健康管理系统软件通用平台,包括后台通用开发引擎和前台个性化定制应用程序编程接口(application programming interface,简称API);最后,提出了大型旋转机组健康管理应用软件“1+3”敏捷化定制开发方案,以通用平台为底座,融合应用对象的数据接入、算法模型封装部署和可视化设计3个关键环节,实现大型旋转机组健康管理应用软件敏捷化开发。通过开放共赢方式让更多模型算法开发者参与构建健康管理业务算法银行,利用系统软件的协同机制解决全生命周期数据整合难题,为构建大型旋转机组健康管理应用软件开发生态奠定基础。

轨道交通列车新一代健康管理系统架构研究

科学维护运营车辆、保障列车运行安全一直以来都是轨道交通领域的核心问题。近年来,随着列车预测性维修和无人驾驶等重大需求的提出,迫切需要实现全息状态感知、精细诊断预测、及时反馈处置的列车健康管理功能。现有系统架构存在着感知低效、融合深度不足、模型优化动态差、计算协同弱、自主化决策水平低等问题,先进的物联网、大数据、人工智能、数字孪生等技术的发展,推动了列车健康管理系统架构向更高水平智能化演进。文章对列车健康管理系统技术发展阶段进行了梳理划分,在此基础上提出了基于泛在感知与协同计算的轨道交通列车健康管理系统4.0架构,详细阐述了其内涵概念、系统架构和关键技术,归纳出泛在感知、协同计算与健康管理深度融合的解决途径、技术手段和预期效果,明确了现阶段技术攻关的主要方向,进而支撑列车安全保障和运维品质的提升。

雷达双层双模健康监视架构设计

雷达设备健康监视主要实现雷达故障预测与健康管理系统的数据解析和显示。传统的监视架构为单一架构层次、面向单一对象的监视架构,并且软件实现与设备紧耦合,其开发和维护成本巨大。文中首次将模型-视图-代理(MVD)模式应用到雷达状态监视架构设计中,提出一种基于MVD的双层双模架构。该架构无需代码定义接口结构体,利用模型工具软件直接编辑设备编号、响应策略,利用高效的封装基类将内置测试设备的状态数据与显示实现挂接;采用“全面+重点”双布局、“用户+专家”双模式设计,可实现目标态势与健康态势同时掌握,并满足用户/专家等不同对象的显示需求。通过工程验证,相比于传统的健康监视架构,该架构提供多样化作战视图,提高了软件可读性、可维护性,节约了软件开发成本,提高了开发效率。