A4 Refereed article in a conference publication

Evaluation of Acoustic Emission as a Predictor of Laser Power in Laser Welding




AuthorsLibutti-Núñez, H H; Hsu, L-W; Parchegani, S; Barros Ribeiro K S; Moreira Bessa, W; Salminen, A

EditorsNadimpalli, Venkata Karthik; Mohanty, Sankhya; Jensen, Dorte Juul; Defer, Marion Caroline; Pan, Zhihao

Conference nameNordic Laser Materials Processing Conference

PublisherIOP Publishing

Publication year2025

JournalIOP Conference Series: Materials Science and Engineering

Book title 20th Nordic Laser Materials Processing Conference

Article number012041

Volume1332

ISSN1757-8981

eISSN1757-899X

DOIhttps://doi.org/10.1088/1757-899X/1332/1/012041

Web address https://doi.org/10.1088/1757-899x/1332/1/012041

Self-archived copy’s web addresshttps://research.utu.fi/converis/portal/detail/Publication/499972314


Abstract

In Laser Welding (LW), multiple sources of data can be used to perform process monitoring. Acoustic Emission (AE) has demonstrated advantages since it does not require severe adaptations into the existing system. Optical microphones, specifically, are capable of sampling signals in the order of MHz, opening a vast possibility for monitoring on high frequency domains. In this work, two methodologies of processing AE are presented, assessing the potential of optical microphones as a robust data source for LW and predictor of the laser power. The experimental setup consisted of 22 bead-on-plate runs on E36 steel, with different laser powers, from 1 kW to 6 kW in 500 W intervals. The experiment was monitored via an optical AE microphone at a sampling rate of 2 MHz, and the acquired signals were split in segments of regular intervals. The first methodology is based on the TSFEL library for feature extraction from the data and the usage of Machine Learning (ML) regressors to predict the laser power. The second is based on computing spectrograms using Short Time Fourier Transform (STFT) and a Convolutional Neural Network (CNN) to predict the laser power. Additionally, each datapoint was then transformed via a 2-dimensional Principal Component Analysis (PCA) reduction for qualitative evaluation. Based on a test set evaluation on unseen data, both methods have achieved a strong prediction performance for the laser power, resulting in a R2 of approximately 0.92 and MAE of approximately 0.3kW. The methodology proposed in this work presents an advancement in AE processing, enabling a digital-first, automated LW monitoring system.


Downloadable publication

This is an electronic reprint of the original article.
This reprint may differ from the original in pagination and typographic detail. Please cite the original version.




Funding information in the publication
The research team acknowledges for the support from the project CaNeLis - Carbon-neutral lightweight ship
structures using advanced design, production, and life-cycle services, which is funded by Meyer Turku Oy, Cavitar Oy, SSAB Europe Oy and Business Finland (3360/31/2022). The project is part of NEcOLEAP leading company
of Meyer Turku Oy.


Last updated on 2025-17-09 at 12:00