Process Monitoring in Friction Stir Welding Using Convolutional Neural Networks

Preliminary studies have shown the superiority of convolutional neural networks (CNNs) compared to other network architectures for determining the surface quality of friction stir welds. In this paper, CNNs were employed to detect cavities inside friction stir welds by evaluating inline measured pro...

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Main Authors: Roman Hartl, Andreas Bachmann, Jan Bernd Habedank, Thomas Semm, Michael F. Zaeh
Format: Article
Language:English
Published: MDPI AG 2021-03-01
Series:Metals
Subjects:
Online Access:https://www.mdpi.com/2075-4701/11/4/535
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author Roman Hartl
Andreas Bachmann
Jan Bernd Habedank
Thomas Semm
Michael F. Zaeh
author_facet Roman Hartl
Andreas Bachmann
Jan Bernd Habedank
Thomas Semm
Michael F. Zaeh
author_sort Roman Hartl
collection DOAJ
description Preliminary studies have shown the superiority of convolutional neural networks (CNNs) compared to other network architectures for determining the surface quality of friction stir welds. In this paper, CNNs were employed to detect cavities inside friction stir welds by evaluating inline measured process data. The aim was to determine whether CNNs are suitable for identifying surface defects exclusively, or if the approach is transferable to internal weld defects. For this purpose, 120 welds were produced and examined by ultrasonic testing, which was the basis for labeling the data as “good” or “defective.” Different types of artificial neural network were tested for predicting the placement of the welds into the defined classes. It was found that the way of labeling the data is significant for the accuracy achievable. When the complete welds were uniformly labeled as “good” or “defective,” an accuracy of 98.5% was achieved by a CNN, which was a significant improvement compared to the state of the art. When the welds were labeled segment-wise, an accuracy of 79.2% was obtained by using a CNN, showing that a segment-wise prediction of the cavities is also possible. The results confirm that CNNs are well suited for process monitoring in friction stir welding and their application enables the identification of various defect types.
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spelling doaj.art-e0546f79c5f3493b8afe2879d7d5c6c62023-11-21T12:02:46ZengMDPI AGMetals2075-47012021-03-0111453510.3390/met11040535Process Monitoring in Friction Stir Welding Using Convolutional Neural NetworksRoman Hartl0Andreas Bachmann1Jan Bernd Habedank2Thomas Semm3Michael F. Zaeh4Institute for Machine Tools and Industrial Management (iwb), Technical University of Munich, 85748 Garching, GermanyInstitute for Machine Tools and Industrial Management (iwb), Technical University of Munich, 85748 Garching, GermanyInstitute for Machine Tools and Industrial Management (iwb), Technical University of Munich, 85748 Garching, GermanyInstitute for Machine Tools and Industrial Management (iwb), Technical University of Munich, 85748 Garching, GermanyInstitute for Machine Tools and Industrial Management (iwb), Technical University of Munich, 85748 Garching, GermanyPreliminary studies have shown the superiority of convolutional neural networks (CNNs) compared to other network architectures for determining the surface quality of friction stir welds. In this paper, CNNs were employed to detect cavities inside friction stir welds by evaluating inline measured process data. The aim was to determine whether CNNs are suitable for identifying surface defects exclusively, or if the approach is transferable to internal weld defects. For this purpose, 120 welds were produced and examined by ultrasonic testing, which was the basis for labeling the data as “good” or “defective.” Different types of artificial neural network were tested for predicting the placement of the welds into the defined classes. It was found that the way of labeling the data is significant for the accuracy achievable. When the complete welds were uniformly labeled as “good” or “defective,” an accuracy of 98.5% was achieved by a CNN, which was a significant improvement compared to the state of the art. When the welds were labeled segment-wise, an accuracy of 79.2% was obtained by using a CNN, showing that a segment-wise prediction of the cavities is also possible. The results confirm that CNNs are well suited for process monitoring in friction stir welding and their application enables the identification of various defect types.https://www.mdpi.com/2075-4701/11/4/535friction stir weldingprocess monitoringconvolutional neural networks
spellingShingle Roman Hartl
Andreas Bachmann
Jan Bernd Habedank
Thomas Semm
Michael F. Zaeh
Process Monitoring in Friction Stir Welding Using Convolutional Neural Networks
Metals
friction stir welding
process monitoring
convolutional neural networks
title Process Monitoring in Friction Stir Welding Using Convolutional Neural Networks
title_full Process Monitoring in Friction Stir Welding Using Convolutional Neural Networks
title_fullStr Process Monitoring in Friction Stir Welding Using Convolutional Neural Networks
title_full_unstemmed Process Monitoring in Friction Stir Welding Using Convolutional Neural Networks
title_short Process Monitoring in Friction Stir Welding Using Convolutional Neural Networks
title_sort process monitoring in friction stir welding using convolutional neural networks
topic friction stir welding
process monitoring
convolutional neural networks
url https://www.mdpi.com/2075-4701/11/4/535
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