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Unsupervised Prognostics based on Deep Virtual Health Index Prediction 基于深度虚拟健康指数预测的无监督预测
Pub Date : 2022-06-29 DOI: 10.36001/phme.2022.v7i1.3359
Martin Hervé de Beaulieu, Mayank Shekhar Jha, H. Garnier, Farid Cerbah
Prediction of the Remaining Useful Life (RUL) for industrial systems has been facilitated by the acquisition of large amounts of real-time data and the use of deep learning methods. However, the vast majority of these methods rely on the availability of extensive RUL-labeled data, which is not the case for most of real industrial applications. The goal of this paper is to show how unsupervised learning can provide alternative ways to address this issue. The proposed method is essentially made of two steps. First, a Virtual Health Index (VHI) is extracted in an unsupervised manner from the raw sensor data using a Deep Convolutional Neural Network (CNN) autoencoder. Secondly, an Long-Short Term Memory (LSTM) Encoder-Decoder predicts the future values of the VHI, until an End-of-Life (EOL) pattern is recognized (using a sliding window DTW algorithm). The suggested method is tested on the C-MAPSS dataset and offers promising results with a great potential to be applicable on real-life use cases.
通过获取大量实时数据和使用深度学习方法,可以促进工业系统剩余使用寿命(RUL)的预测。然而,这些方法中的绝大多数依赖于广泛的rl标记数据的可用性,这对于大多数实际工业应用来说并非如此。本文的目的是展示无监督学习如何提供解决这一问题的替代方法。所提出的方法基本上由两个步骤组成。首先,使用深度卷积神经网络(CNN)自编码器从原始传感器数据中以无监督的方式提取虚拟健康指数(VHI)。其次,长短期记忆(LSTM)编码器-解码器预测VHI的未来值,直到生命周期结束(EOL)模式被识别(使用滑动窗口DTW算法)。建议的方法在C-MAPSS数据集上进行了测试,并提供了有希望的结果,具有应用于现实生活用例的巨大潜力。
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引用次数: 2
A Hierarchical XGBoost Early Detection Method for Quality and Productivity Improvement of Electronics Manufacturing Systems 电子制造系统质量和生产率改进的分层XGBoost早期检测方法
Pub Date : 2022-06-29 DOI: 10.36001/phme.2022.v7i1.3370
A. Gaffet, Nathalie Barbosa Roa, P. Ribot, E. Chanthery, C. Merle
This paper presents XGBoost classifier-based methods to solve three tasks proposed by the European Prognostics and Health Management Society (PHME) 2022 conference. These tasks are based on real data from a Surface Mount Technologies line. Each of these tasks aims to improve the efficiency of the Printed Circuit Board (PCB) manufacturing process, facilitate the operator’s work and minimize the cases of manual intervention. Due to the structured nature of the problems proposed for each task, an XGBoost method based on encoding and feature engineering is proposed. The proposed methods utilise the fusion of test values and system characteristics extracted from two different testing equipment of the Surface Mount Technologies lines. This work also explores the problems of generalising prediction at the system level using information from the subsystem data. For this particular industrial case: the challenges with the changes in the number of subsystems. For Industry 4.0, the need for interpretability is very important. This is why the results of the models are analysed using Shapley values. With the proposed method, our team took the first place, capable of successfully detecting at an early stage the defective components for tasks 2 and 3.
本文提出了基于XGBoost分类器的方法来解决欧洲预后和健康管理学会(PHME) 2022年会议提出的三个任务。这些任务都是基于来自Surface Mount Technologies生产线的真实数据。这些任务中的每一项都旨在提高印刷电路板(PCB)制造过程的效率,方便操作员的工作,并最大限度地减少人工干预的情况。由于每个任务所提出问题的结构化性质,提出了一种基于编码和特征工程的XGBoost方法。所提出的方法利用了从表面贴装技术生产线的两个不同测试设备中提取的测试值和系统特性的融合。这项工作还探讨了利用子系统数据中的信息在系统级推广预测的问题。对于这个特殊的工业案例:子系统数量变化带来的挑战。对于工业4.0,对可解释性的需求非常重要。这就是为什么使用Shapley值来分析模型的结果。通过提出的方法,我们的团队获得了第一名,能够在任务2和3的早期阶段成功地检测到有缺陷的组件。
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引用次数: 0
Prognosis of Wear Progression in Electrical Brakes for Aeronautical Applications 航空电制动器磨损过程的预测
Pub Date : 2022-06-29 DOI: 10.36001/phme.2022.v7i1.3353
Andrea De Martin, G. Jacazio, Vincenzo Parisi, M. Sorli
The evolution towards “more electric” aircrafts has seen a decisive push in the last decade, due to the growing environmental concerns and the development of new market segments (flying taxis). Such push interested both the propulsion components and the aircraft systems, with the latter seeing a progressive trend in replacing the traditional solutions based on hydraulic power with electrical or electromechanical devices. Although more attention is usually devised towards the flight control actuation, an interesting and fast-developing application field for electro-mechanical systems is that of the aeronautical brakes. Electro-mechanical brakes, or E-Brakes hereby onwards, would present several advantages over their hydraulic counterparts, mainly related to the avoidance of leakage issues and the simplification of the system architecture. The more difficult heat dissipation, associated with the thermal issues that usually constitute one of the most significant sizing constraints for electromechanical actuators, limits so far, their application (or proposal of application) to light-weight vehicles. Within this context, the development of PHM solutions would align with the need for an on-line monitoring of a relatively unproven component. This paper deals with the preliminary stages of the development of such PHM system for an E-Brake to be employed on a future executive class aircraft, where the brake is actuated through four electro-mechanical actuators. Since literature on fault diagnosis and prognosis for electrical motors is fairly extensive, we focused this preliminary analysis on the development of PHM techniques suitable to monitor and prognose the evolution of the brake pads wear instead. The paper opens detailing the system architecture and continues presenting the high-fidelity dynamic model used to build synthetic data-sets representative of the possible operating conditions faced by the E-Brake within realistic operative scenarios. Such data are then used to foster a preliminary feature selection process, where physics-based indexes are compared and evaluated. Simulated degradation histories are then used to test the application of data-driven fault detection algorithm and the possible application of particle-filtering routines for prognosis.
在过去十年中,由于日益增长的环境问题和新细分市场(飞行出租车)的发展,“更电动”飞机的发展得到了决定性的推动。这种推动对推进部件和飞机系统都很感兴趣,后者看到了用电气或机电设备取代基于液压动力的传统解决方案的进步趋势。虽然飞行控制驱动通常受到更多的关注,但机电系统的一个有趣和快速发展的应用领域是航空刹车。电子机械制动器(以下简称e -制动器)与液压制动器相比有几个优势,主要与避免泄漏问题和简化系统架构有关。更困难的散热,与热问题相关,通常构成机电致动器最重要的尺寸限制之一,到目前为止,限制了它们在轻型车辆上的应用(或应用建议)。在这种情况下,PHM解决方案的开发将与在线监测相对未经验证的组件的需求保持一致。本文讨论了用于未来行政级飞机的电子制动器的PHM系统开发的初步阶段,其中制动器通过四个机电致动器驱动。由于关于电动机故障诊断和预测的文献相当广泛,因此我们将初步分析的重点放在适合监测和预测刹车片磨损演变的PHM技术的发展上。本文详细介绍了系统架构,并继续介绍了用于构建代表E-Brake在实际操作场景中可能面临的操作条件的综合数据集的高保真动态模型。然后,这些数据用于培养初步的特征选择过程,其中基于物理的指标进行比较和评估。然后使用模拟的退化历史来测试数据驱动的故障检测算法的应用以及粒子滤波例程预测的可能应用。
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引用次数: 0
Design and validation of scalable PHM solutions for aerospace onboard systems 为航空机载系统设计和验证可扩展的 PHM 解决方案
Pub Date : 2022-06-29 DOI: 10.36001/phme.2022.v7i1.3333
F. Federici, C. Tonelli, M. Le Cam, Marcello Torchio, David Larsen
In recent years, Prognostic & Health Management (PHM) has become a topic of strong interest in the aerospace domain. Health assessment and remaining useful life estimation for on-board systems provide several advantages, mainly related to the increased analysis capabilities and the reduction of maintenance interventions (and, consequently, of operating costs). For this reason, it is of interest for the aerospace industry to identify and define efficient strategies both for the introduction of native PHM capabilities in new generation on-board systems and for the retrofit of existing ones. This paper proposes a strategy for the scalable deployment of PHM techniques for on-board systems, with particular focus on edge computing capabilities. Different reference scenarios (ranging from cloud-based processing to local-only processing) are presented, and an edge-focused PHM architecture is discussed in detail, with the relative challenges addressed. The design and validation of proposed edge-based solution is described, with specific reference to its support for an existing data analytics framework. The solution is then assessed against a reference aerospace use case involving a representative aircraft braking system, focusing on computational aspects to highlight the compatibility of the proposed deployment strategy with efficient on-board computations.
近年来,预知与健康管理(PHM)已成为航空航天领域备受关注的话题。机载系统的健康评估和剩余使用寿命估算具有多种优势,主要涉及提高分析能力和减少维护干预(进而降低运营成本)。因此,航空航天工业有兴趣为新一代机载系统引入本地 PHM 功能和现有系统的改造确定和定义有效的策略。本文针对机载系统 PHM 技术的可扩展部署提出了一项战略,并特别关注边缘计算能力。本文介绍了不同的参考方案(从基于云的处理到仅本地处理),详细讨论了以边缘为重点的 PHM 架构,并解决了相关挑战。介绍了拟议的基于边缘的解决方案的设计和验证,特别提到了它对现有数据分析框架的支持。然后,根据涉及代表性飞机制动系统的参考航空用例对该解决方案进行了评估,重点关注计算方面,以突出拟议部署策略与高效机载计算的兼容性。
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引用次数: 0
Data-driven Prognostics based on Evolving Fuzzy Degradation Models for Power Semiconductor Devices 基于演化模糊退化模型的功率半导体器件数据驱动预测
Pub Date : 2022-06-29 DOI: 10.36001/phme.2022.v7i1.3338
Khoury Boutrous, I. Bessa, V. Puig, F. Nejjari, R. Palhares
The increasing application of power converter systems based on semiconductor devices such as Insulated-Gate Bipolar Transistors (IGBTs) has motivated the investigation of strategies for their prognostics and health management. However, physicsbased degradation modelling for semiconductors is usually complex and depends on uncertain parameters, which motivates the use of data-driven approaches. This paper addresses the problem of data-driven prognostics of IGBTs based on evolving fuzzy models learned from degradation data streams. The model depends on two classes of degradation features: one group of features that are very sensitive to the degradation stages is used as a premise variable of the fuzzy model, and another group that provides good trendability and monotonicity is used for the auto-regressive consequent of the fuzzy model for degradation prediction. This strategy allows obtaining interpretable degradation models, which are improved when more degradation data is obtained from the Unit Under Test (UUT) in real time. Furthermore, the fuzzy-based Remaining Useful Life (RUL) prediction is equipped with an uncertainty quantification mechanism to better aid decisionmakers. The proposed approach is then used for the RUL prediction considering an accelerated aging IGBT dataset from the NASA Ames Research Center.
基于半导体器件(如绝缘栅双极晶体管(igbt))的功率转换器系统的应用越来越多,这促使了对其预后和健康管理策略的研究。然而,基于物理的半导体退化建模通常是复杂的,并且依赖于不确定的参数,这促使使用数据驱动的方法。本文研究了基于退化数据流学习的演化模糊模型的igbt数据驱动预测问题。该模型依赖于两类退化特征:一组对退化阶段非常敏感的特征作为模糊模型的前提变量,另一组提供良好的趋势性和单调性的特征作为模糊模型的自回归结果进行退化预测。该策略允许获得可解释的退化模型,当从被测单元(UUT)实时获得更多的退化数据时,该模型得到了改进。此外,基于模糊的剩余使用寿命(RUL)预测具有不确定性量化机制,可以更好地辅助决策者。然后将提出的方法用于考虑NASA艾姆斯研究中心加速老化的IGBT数据集的RUL预测。
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引用次数: 2
Application, Utility and Acceptability of Data Analytics in Safety Risk Management of Airline Operations 数据分析在航空公司安全风险管理中的应用、效用和可接受性
Pub Date : 2022-06-29 DOI: 10.36001/phme.2022.v7i1.3295
Washington Mhangami, S. King, Dave Barry
One area the aviation industry is grappling with is the quantification of the probability of occurrence of safety incidents. Currently, aviation professionals involved in safety risk management mostly rely on collective experience to determine probability of incident occurrences and apply it to the International Civil Aviation Organisation (ICAO) matrix or equivalent to evaluate the risk. A number of limitations linked to the use of risk matrices will be explored in this paper. It is the aim of this paper to explore statistical methods that can be used to determine the probability of safety occurrences and come up with an algorithm that can be used by airlines using available safety data. The novelty of this research is that it combines the exploration of use of statistical techniques to quantitatively assess risk using Flight Data Monitoring (FDM) and other data, with acceptability of Safety Risk Management (SRM) data analytics by operational personnel. The paper also explores the contributory factors leading to the reluctance of operational personnel to use data analytics to inform their risk assessments despite the increasing availability of operational data and advancement in technology.
航空业正在努力解决的一个问题是安全事故发生概率的量化。目前,参与安全风险管理的航空专业人员大多依靠集体经验来确定事件发生的概率,并将其应用于国际民航组织(ICAO)矩阵或等效矩阵来评估风险。本文将探讨与使用风险矩阵有关的一些限制。本文的目的是探索可用于确定安全事件概率的统计方法,并提出一种可由航空公司使用可用安全数据的算法。本研究的新颖之处在于,它结合了探索使用统计技术,利用飞行数据监测(FDM)和其他数据定量评估风险,以及操作人员对安全风险管理(SRM)数据分析的可接受性。本文还探讨了导致操作人员不愿使用数据分析来进行风险评估的因素,尽管操作数据的可用性越来越高,技术也在进步。
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引用次数: 0
Physics Informed Neural Network for Health Monitoring of an Air Preheater 空气预热器健康监测的物理通知神经网络
Pub Date : 2022-06-29 DOI: 10.36001/phme.2022.v7i1.3343
Vishal Jadhav, A. Deodhar, Ashit Gupta, V. Runkana
Air Preheater (APH) is a regenerative heat exchanger employed in thermal power plants to save fuel by improving their thermal efficiency. Monitoring the health of APH vis-a-vis its fouling is critical because fouling often results in forced outages of the power plant, incurring huge revenue losses. APH fouling is a complex thermo-chemical phenomenon governed by flue gas composition, operating temperatures, fuel type and ambient conditions. Absence of sensors within the APH make it difficult to estimate the level of fouling and its progression even for an experienced operator. Attempts to estimate APH fouling in real-time via modeling are scarce. Here we present a physics-informed neural network (PINN) that tracks the health of an APH by real-time estimation of fouling conditions within the APH as a function of real-time sensor measurements. To account for multi-fluid operation in a multi-sector design of APH, the domain is decomposed into several sub-domains. PINN is applied to each sub-domain and the overall solution is ensured by applying continuity conditions at the sub-domain interfaces. The model predicts the interior temperatures and fouling zones within the APH using external sensor measurements such as air temperature and gas composition. The model predictions are consistent with physics and yet computationally efficient in run-time. The model does not need sensor data but can be improved further by accommodating available sensor data. The real-time predictions by the model improve operator’s visibility in fouling. The predictions can be used further for estimating the remaining useful cycle life of the APH, thereby avoiding forced outages. The model can easily be integrated with the digital twin of an APH for its predictive maintenance.
空气预热器(APH)是热电厂采用的一种蓄热式换热器,通过提高热效率来节省燃料。监测APH的健康状况及其污垢是至关重要的,因为污垢经常导致电厂被迫停机,造成巨大的收入损失。APH结垢是一种复杂的热化学现象,受烟气成分、操作温度、燃料类型和环境条件的影响。APH内没有传感器,即使是经验丰富的操作人员也很难估计结垢程度及其进展。通过建模来实时估计APH污染的尝试很少。在这里,我们提出了一个物理信息神经网络(PINN),它通过实时估计APH内的污垢状况来跟踪APH的健康状况,作为实时传感器测量的函数。为了考虑APH多扇区设计中的多流体操作,将该域分解为几个子域。将PINN应用于每个子域,并通过在子域接口处应用连续性条件来保证整体解决方案。该模型使用外部传感器测量(如空气温度和气体成分)来预测APH内部温度和污垢区域。模型预测符合物理规律,运行时计算效率高。该模型不需要传感器数据,但可以通过容纳可用的传感器数据进一步改进。该模型的实时预测提高了操作人员对结垢的可视性。这些预测可以进一步用于估计APH的剩余有效循环寿命,从而避免强制停机。该模型可以很容易地与APH的数字孪生体集成,以进行预测性维护。
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引用次数: 5
Novel Methodology for Health Assessment in Printed Circuit Boards 印刷电路板健康评估的新方法
Pub Date : 2022-06-29 DOI: 10.36001/phme.2022.v7i1.3373
J. Taco, Prayag Gore, T. Minami, Pradeep Kundu, J. Lee
The demand for Printed circuit boards (PCBs) has increased due to the rapid change in technology in recent years. Consequently, PCBs health assessment and fault detection play an important role in improving productivity. This study proposed a novel method which focused on feature engineering for health assessment in PCBs. The performance of the proposed method has been validated using data obtained from PHM Europe 2022 data challenge. In this data challenge, PCBs health assessment needs to be performed with data from the Solder Paste Inspection (SPI) and the Automated Optical Inspection (AOI) machine. The challenge has three tasks: 1) Predict the labels of the AOI machine using the SPI data. 2) Using both the SPI and AOI machine data, predict the operator's verification that the AOI machine correctly detected a defect. 3) With the SPI and AOI data, predict the classification of the defective PCBs as either repairable or unrepairable. The component level features are extracted from the original SPI and AOI data which contain the pin level features to solve these tasks. Two machine learning-based classification models, i.e., Light Gradient Boosting Machine (LightGBM) and eXtreme Gradient Boosting (XGBoost), have been used for classification purposes. Training data given by the organizer was divided into 70% training and 30% validation. Based on the validation data, the highest F1-score was observed with LightGBM in Tasks 1 and 2, whereas, in Task 3, the highest F1-score was observed with the XGBoost model. Hence, the LightGBM model has been used in Tasks 1 and 2, and the XGBoost model was developed for Task 3.
近年来,由于技术的快速变化,对印刷电路板(pcb)的需求有所增加。因此,多氯联苯健康评估和故障检测在提高生产效率方面发挥着重要作用。本研究提出了一种基于特征工程的多氯联苯健康评价新方法。利用PHM Europe 2022数据挑战获得的数据验证了所提出方法的性能。在这个数据挑战中,pcb健康评估需要使用锡膏检测(SPI)和自动光学检测(AOI)机器的数据来执行。挑战有三个任务:1)使用SPI数据预测AOI机器的标签。2)同时使用SPI和AOI机器数据,预测操作员验证AOI机器正确检测到缺陷。3)根据SPI和AOI数据,预测不良pcb的可修复或不可修复分类。从包含引脚级特征的原始SPI和AOI数据中提取组件级特征来解决这些任务。两种基于机器学习的分类模型,即Light Gradient Boosting machine (LightGBM)和eXtreme Gradient Boosting (XGBoost),已经被用于分类目的。组织者提供的培训数据分为70%的培训和30%的验证。从验证数据来看,在Task 1和Task 2中,LightGBM模型的f1得分最高,而在Task 3中,XGBoost模型的f1得分最高。因此,在Task 1和Task 2中使用了LightGBM模型,而在Task 3中开发了XGBoost模型。
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引用次数: 3
On the Integration of Fundamental Knowledge about Degradation Processes into Data-Driven Diagnostics and Prognostics Using Theory-Guided Data Science 利用理论指导的数据科学将退化过程的基础知识集成到数据驱动的诊断和预测中
Pub Date : 2022-06-29 DOI: 10.36001/phme.2022.v7i1.3352
Simon Hagmeyer, P. Zeiler, Marco F. Huber
In Prognostics and Health Management, there are three main approaches for implementing diagnostic and prognostic applications. These approaches are data-driven methods, physical model-based methods, and combinations of them, in the form of hybrid methods. Each of them has specific advantages but also limitations for their purposeful implementation. In the case of data-driven methods, one of the main limitations is the availability of sufficient training data that adequately cover the relevant state space. For model-based methods, on the other hand, it is often the case that the degradation process of the considered technical system is of significant complexity. In such a scenario physics-based modeling requires great effort or is not possible at all. Combinations of data-driven and model-based approaches in form of hybrid approaches offer the possibility to partially mitigate the shortcomings of the other two approaches, however, require a sufficiently detailed data-driven and physics-based model.This paper addresses the transitional field between data-driven and hybrid approaches. Despite the issues of formulating a physics-based model that provides a representation of the degradation process, basic knowledge of the considered system and of the laws governing its degradation process is usually available. Integration of such knowledge into a machine learning process is part of a research field that is either called theory-guided data science, (physics) informed machine learning, physics-based learning or physics guided machine learning. First, the state of research in Prognostics and Health Management on methods of this field is presented and existing research gaps are outlined. Then, a concept is introduced for incorporating fundamental knowledge, such as monotonicity constraints, into data-driven diagnostic and prognostic applications using approaches from theory-guided data science. A special aspect of this concept is its cross-application usability through the consideration of knowledge that repeatedly occurs in diagnostics and prognostics. This is, for example, knowledge about physically justified boundaries whose compliance makes a prediction of the data-driven model plausible in the first place.
在预后和健康管理中,有三种实现诊断和预后应用的主要方法。这些方法是数据驱动的方法,基于物理模型的方法,以及以混合方法的形式将它们组合在一起。它们中的每一个都有特定的优点,但对于它们的有目的的实现也有限制。在数据驱动的方法中,主要的限制之一是缺乏足够的训练数据来充分覆盖相关的状态空间。另一方面,对于基于模型的方法,通常情况下所考虑的技术系统的退化过程非常复杂。在这种情况下,基于物理的建模需要很大的努力,或者根本不可能。以混合方法的形式将数据驱动和基于模型的方法结合起来,可以部分地减轻其他两种方法的缺点,但是,需要一个足够详细的数据驱动和基于物理的模型。本文讨论了数据驱动和混合方法之间的过渡领域。尽管制定一个基于物理的模型来提供退化过程的表示存在问题,但是所考虑的系统的基本知识和控制其降解过程的规律通常是可用的。将这些知识集成到机器学习过程中是一个研究领域的一部分,该领域被称为理论指导数据科学、(物理)知情机器学习、基于物理的学习或物理指导机器学习。首先,介绍了预后与健康管理在该领域的研究现状和方法,并概述了现有的研究差距。然后,介绍了一个概念,将单调性约束等基础知识结合到数据驱动的诊断和预测应用中,使用理论指导的数据科学方法。这个概念的一个特殊方面是它的跨应用的可用性,通过考虑在诊断和预测中反复出现的知识。例如,这是关于物理上合理的边界的知识,其遵从性首先使数据驱动模型的预测变得合理。
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引用次数: 3
Noise-Robust Representation for Fault Identification with Limited Data via Data Augmentation 基于数据增强的有限数据故障识别的噪声鲁棒表示
Pub Date : 2022-06-29 DOI: 10.36001/phme.2022.v7i1.3334
Zahra Taghiyarrenani, A. Berenji
Noise will be unavoidably present in the data collected from physical environments, regardless of how sophisticated the measurement equipment is. Furthermore, collecting enough faulty data is a challenge since operating industrial machines in faulty modes not only has severe consequences to the machine health, but also may affect collateral machinery critically, from health state point of view. In this paper, we propose a method of denoising with limited data for the purpose of fault identification. In addition, our method is capable of removing multiple levels of noise simultaneously. For this purpose, inspired by unsupervised contrastive learning, we first augment the data with multiple levels of noise. Later, we construct a new feature representation using Contrastive Loss. The last step is building a classifier on top of the learned representation; this classifier can detect various faults in noisy environments. The experiments on the SOUTHEAST UNIVERSITY (SEU) dataset of bearings confirm that our method can simultaneously remove multiple noise levels.
无论测量设备有多精密,从物理环境中收集的数据都不可避免地存在噪声。此外,收集足够的故障数据是一项挑战,因为在故障模式下运行工业机器不仅会对机器健康造成严重后果,而且从健康状态的角度来看,还可能严重影响附属机器。本文提出了一种基于有限数据去噪的故障识别方法。此外,我们的方法能够同时去除多级噪声。为此,受无监督对比学习的启发,我们首先用多级噪声增强数据。随后,我们利用对比损失构造了一个新的特征表示。最后一步是在学习到的表示之上建立一个分类器;该分类器可以在噪声环境中检测出各种故障。在东南大学(SEU)轴承数据集上的实验证实了该方法可以同时去除多个噪声级。
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引用次数: 1
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