Change search
Link to record
Permanent link

Direct link
Publications (10 of 50) Show all publications
Rahmani Dehaghani, M., Sahraeidolatkhaneh, A., Nilsen, M., Sikström, F., Sajadi, P., Tang, Y. & Wang, G. G. (2024). System identification and closed-loop control of laser hot-wire directed energy deposition using the parameter-signature-quality modeling scheme. Journal of Manufacturing Processes, 1-13
Open this publication in new window or tab >>System identification and closed-loop control of laser hot-wire directed energy deposition using the parameter-signature-quality modeling scheme
Show others...
2024 (English)In: Journal of Manufacturing Processes, ISSN 1526-6125, p. 1-13Article in journal (Refereed) Published
Abstract [en]

Hot-wire directed energy deposition using a laser beam (DED-LB/w) is a method of metal additive manufacturing (AM) that has benefits of high material utilization and deposition rate, but parts manufactured by DED-LB/w suffer from a substantial heat input and undesired surface finish. Hence, regulating the process parameters and monitoring the process signatures to control the final quality during the deposition is crucial to ensure the quality of the final part. This paper explores the dynamic modeling of the DED-LB/w process and introduces a parameter-signature-quality modeling and control approach to enhance the quality of modeling and control of part qualities that cannot be measured in situ. The study investigates different process parameters that influence the melt pool width (signature) and bead width (quality) in single and multi-layer beads. The proposed modeling approach utilizes a parameter-signature model as F1 and a signature-quality model as F2. Linear and nonlinear modeling approaches are compared to describe a dynamic relationship between process parameters and a process signature, the melt pool width (F1). A fully connected artificial neural network is employed to model and predict the final part quality, i.e., bead width, based on melt pool signatures (F2). Finally, the effectiveness and usefulness of the proposed parameter-signature-quality modeling is tested and verified by integrating the parameter-signature (F1) and signature-quality (F2) models in the closed-loop control of the width of the part. Compared with the control loop with only F1, the proposed method shows clear advantages and bears potential to be applied to control other part qualities that cannot be directly measured or monitored in situ.

Keywords
Laser hot-wire directed energy deposition System identification, Multi-layer perceptron, In situ monitoring, Closed-loop control
National Category
Manufacturing, Surface and Joining Technology
Research subject
Production Technology
Identifiers
urn:nbn:se:hv:diva-21214 (URN)10.1016/j.jmapro.2024.01.029 (DOI)
Available from: 2024-01-19 Created: 2024-01-19 Last updated: 2024-01-19
Fang, J., Wang, Z., Liu, W., Lauria, S., Zeng, N., Prieto, C., . . . Liu, X. (2023). A New Particle Swarm Optimization Algorithm for Outlier Detection: Industrial Data Clustering inWire Arc Additive Manufacturing. IEEE Transactions on Automation Science and Engineering, 1-14
Open this publication in new window or tab >>A New Particle Swarm Optimization Algorithm for Outlier Detection: Industrial Data Clustering inWire Arc Additive Manufacturing
Show others...
2023 (English)In: IEEE Transactions on Automation Science and Engineering, ISSN 1545-5955, E-ISSN 1558-3783, p. 1-14Article in journal (Refereed) Epub ahead of print
Abstract [en]

In this paper, a novel outlier detection method is proposed for industrial data analysis based on the fuzzy C-means (FCM) algorithm. An adaptive switching randomly perturbed particle swarm optimization algorithm (ASRPPSO) is put forward to optimize the initial cluster centroids of the FCM algorithm. The superiority of the proposed ASRPPSO is demonstrated over five existing PSO algorithms on a series of benchmark functions. To illustrate its application potential, the proposed ASRPPSO-based FCM algorithm is exploited in the outlier detection problem for analyzing the real-world industrial data collected from a wire arc additive manufacturing pilot line in Sweden. Experimental results demonstrate that the proposed ASRPPSO-based FCM algorithm out performs the standard FCM algorithm in detecting outliers of real-world industrial data.

Note to Practitioners

Electric arc (which is governed by the current and arc voltage) plays a significant role in monitoring the operating status of the wire arc additive manufacturing (WAAM) process. The nominal periodic current and voltage may occasionally change abruptly due to anomalies (such asarc instability, unstable metal transfer, geometrical deviations, and surface contaminations), which would affect the quality of the fabricated component. This paper focuses on detecting possible anomalies by analyzing the current and voltage during the WAAM process. A novel clustering-based outlier detection method is proposed for anomaly detection where abnormal and normal instances are categorized into two separate clusters. A new particle swarm optimization algorithm is put forward to optimize the initial cluster centroid so as to improve the detection accuracy. The proposed outlier detection method is applied to real-world data collected from a WAAM pilot line for detecting abnormal instances. Experimental results demonstrate the effectiveness of the proposed outlier detection method. The proposed outlier detection method can be applied to other industrial applications including electrical engineering, mechanical engineering and medical engineering. In the future, we aim to develop an online outlier detection system based on the proposed method for real-time for anomaly detection and defect prediction.

Keywords
Industrial data analysis, outlier detection, fuzzy C-means, particle swarm optimization, wire arc additive manufacturing
National Category
Manufacturing, Surface and Joining Technology
Research subject
Production Technology
Identifiers
urn:nbn:se:hv:diva-19942 (URN)10.1109/TASE.2022.3230080 (DOI)000910587300001 ()2-s2.0-85147228838 (Scopus ID)
Available from: 2024-02-15 Created: 2024-02-15 Last updated: 2024-04-12
Mi, Y., Guglielmi, P., Nilsen, M., Sikström, F., Palumbo, G. & Ancona, A. (2023). Beam shaping with a deformable mirror for gap bridging in autogenous laser butt welding. Optics and Lasers in Engineering, 169, Article ID 107724.
Open this publication in new window or tab >>Beam shaping with a deformable mirror for gap bridging in autogenous laser butt welding
Show others...
2023 (English)In: Optics and Lasers in Engineering, ISSN 0143-8166, Vol. 169, article id 107724Article in journal (Refereed) Published
Abstract [en]

In autogenous laser butt welding the variability of the joint gap can cause problems in terms of weld seam quality. A suitable strategy to alleviate this is to dynamically shape the laser beam instead of a circular-shaped beam with typical Gaussian or top hat distributions. Currently available systems cannot reach sufficient performance due to both the real time control system for the shape variation and the limited laser power currently manageable. In the present work, the possibility of bridging the joint gap during welding using a deformable mirror to elongate the focused laser beam from circular to transversal elliptical shape was investigated. The effect of the beam shaping on the geometry of the weld pool and of the weld cross sections was analysed, for different values of the gap in comparison with a circular Gaussian beam. It was demonstrated that the adoption of a transversal elliptical laser beam makes the welding process more stable, especially for large gaps (i.e. larger than the circular beam radius). Thanks to the beam shaping, the extension of the fused zone (in terms of the cross section area, height and width) resulted to be less sensitive to the gap's dimension; in addition, the extension of the heat affected zone and the presence of undercuts were evidently reduced.

Keywords
Laser beam welding, Beam shaping, Process monitoring, Microstructure, Steel
National Category
Manufacturing, Surface and Joining Technology
Research subject
Production Technology
Identifiers
urn:nbn:se:hv:diva-20684 (URN)10.1016/j.optlaseng.2023.107724 (DOI)001041329900001 ()2-s2.0-85164226707 (Scopus ID)
Funder
Knowledge Foundation, 20170315Knowledge Foundation, 20210094
Available from: 2023-12-29 Created: 2023-12-29 Last updated: 2024-03-15Bibliographically approved
Noori Rahim Abadi, S. M., Mi, Y., Kisielewicz, A., Sikström, F. & Choquet, I. (2023). Influence of laser-wire interaction on heat and metal transfer in directed energy deposition. International Journal of Heat and Mass Transfer, 205, Article ID 123894.
Open this publication in new window or tab >>Influence of laser-wire interaction on heat and metal transfer in directed energy deposition
Show others...
2023 (English)In: International Journal of Heat and Mass Transfer, ISSN 0017-9310, E-ISSN 1879-2189, Vol. 205, article id 123894Article in journal (Refereed) Published
Abstract [en]

In this study, laser metal fusion with feedstock wire is addressed. We investigated how various process parameters affect the fraction of beam energy that is absorbed by the wire and the workpiece and the metal transfer from the feedstock wire to the melt pool. To perform this research, a thermo-fluid dynamic model with tracking of free surface deformation was developed to include the feeding of a solid wire and predict its melting. The fraction of beam energy absorbed by the metal was modeled as a function of local surface curvature and temperature, accounting for multiple Fresnel reflections and absorptions. The model was applied to Titanium alloy (Ti-6Al-4V) with a 1.07 μm laser and a process in conduction mode. Experiments at various wire feeding rates were conducted to evaluate the model’s ability to predict the process and a good agreement was obtained. The different parameters studied were the beam angular position, the wire angular position, the wire feed rate, and the beam-wire offset. The analysis of the simulation results gave a detailed physical understanding of the laser energy use. It highlighted that thermocapillary and Rayleigh-Plateau instabilities can contribute to the transition from continuous to drop metal transfer mode. Damping these instabilities might thus allow using a wider process window.

Keywords
Laser beam, Feedstock wire, Metal fusion, Metal deposition, Energy deposition, Process stability, CFD Simulation
National Category
Manufacturing, Surface and Joining Technology
Research subject
Production Technology
Identifiers
urn:nbn:se:hv:diva-20037 (URN)10.1016/j.ijheatmasstransfer.2023.123894 (DOI)000965022600001 ()2-s2.0-85147203744 (Scopus ID)
Funder
Knowledge Foundation, 20170315
Note

 CC BY-NC-ND 

This research work was supported by grants from the Swedish Knowledge Foundation, projects AdOpt (20170315) and SAMw(20170060), which is gratefully acknowledged.

Available from: 2023-06-13 Created: 2023-06-13 Last updated: 2024-01-08Bibliographically approved
Ancona, A., Sikström, F., Christiansson, A.-K., Nilsen, M., Mi, Y. & Kisielewicz, A. (2023). Monitoring and control of directed energy deposition using a laser beam (1.ed.). In: Pederson, Robert, Andersson, Joel & Joshi, Shrikant V. (Ed.), Additive Manufacturing of High-Performance metallic Materials: (pp. 612-638). Elsevier
Open this publication in new window or tab >>Monitoring and control of directed energy deposition using a laser beam
Show others...
2023 (English)In: Additive Manufacturing of High-Performance metallic Materials / [ed] Pederson, Robert, Andersson, Joel & Joshi, Shrikant V., Elsevier, 2023, 1., p. 612-638Chapter in book (Refereed)
Abstract [en]

To be a successful competitor among other technologies, metallic laser-directed energy depositionusing a laser beam would benefit from the support of intelligent automation making the processrobust, repeatable, and cost-efficient. This calls for technology leaps towards robust and accuratedetection and estimation of the conditions during processing and control schemes for robustperformance. This chapter discusses how developments in sensor technology and model-basedsignal processing can contribute to advancements in in-process monitoring of directed energydeposition using a laser beam and how developments in model-based feedforward- and feedbackcontrol can support automation. The focus is on how machine vision, optical emission spectroscopy,thermal sensing, and electrical process signals can support monitoring, control and better processunderstanding. These approaches are industrially relevant and have a high potential to support amore sustainable manufacturing. 

Place, publisher, year, edition, pages
Elsevier, 2023 Edition: 1.
Keywords
Directed energy deposition using a laser beam; Electrical process signals; Feedstock wire and powder; Infrared imaging; Machine vision; Model-based control; Photo detection; Radiation pyrometry; Signal processing; Spectroscopy
National Category
Manufacturing, Surface and Joining Technology
Research subject
Production Technology
Identifiers
urn:nbn:se:hv:diva-21079 (URN)9780323918855 (ISBN)9780323913829 (ISBN)
Available from: 2023-12-14 Created: 2023-12-14 Last updated: 2024-01-11Bibliographically approved
Kisielewicz, A., Mi, Y., Sikström, F. & Ancona, A. (2023). Multi sensor monitoring  of the wire-melt pool interaction inhot-wire directed energy deposition using laser beam. In: IOP Conference Series: Materials Science and Engineering. Paper presented at NOLAMP 19th Nordic Laser Material Processing Conference 22-24 August 2023 Turku, Finland (pp. 1-11). IOP Publishing, 1296, Article ID 012011.
Open this publication in new window or tab >>Multi sensor monitoring  of the wire-melt pool interaction inhot-wire directed energy deposition using laser beam
2023 (English)In: IOP Conference Series: Materials Science and Engineering, IOP Publishing , 2023, Vol. 1296, p. 1-11, article id 012011Conference paper, Oral presentation with published abstract (Refereed)
Abstract [en]

This study investigates the combination of three sensors to improve in-process monitoring of the liquid bridge between the feedstock wire and melt pool in hot-wire Directed Energy Deposition using Laser Beam. The stability of the deposition process relies on the transfer of metal between the molten feedstock wire and melt pool. Therefore, monitoring the condition of the liquid bridge and the interaction between the feedstock wire and melt pool is crucial. By utilizing a laser-optics-integrated visible range optical spectrometer and electrical sensors measuring voltage and current, relevant process changes and indications of instabilities were detected. Combined information from the current sensor and the spectrometer provided a better understanding of the process and helped to identify deviations leading to unstable deposition modes.

Place, publisher, year, edition, pages
IOP Publishing, 2023
Keywords
wire-melt, laser beam, multi sensor monitoring
National Category
Manufacturing, Surface and Joining Technology
Research subject
Production Technology
Identifiers
urn:nbn:se:hv:diva-20863 (URN)10.1088/1757-899X/1296/1/012011 (DOI)
Conference
NOLAMP 19th Nordic Laser Material Processing Conference 22-24 August 2023 Turku, Finland
Funder
Swedish Research Council, SAMw [20170060]Vinnova, InAIRwire [2019-02752]
Note

CC BY 3.0

Available from: 2024-02-15 Created: 2024-02-15 Last updated: 2024-02-15
Jadidi, A., Mi, Y., Sikström, F., Nilsen, M. & Ancona, A. (2022). Beam Offset Detection in Laser Stake Welding of Tee Joints Using Machine Learning and Spectrometer Measurements. Sensors, 22(10)
Open this publication in new window or tab >>Beam Offset Detection in Laser Stake Welding of Tee Joints Using Machine Learning and Spectrometer Measurements
Show others...
2022 (English)In: Sensors, E-ISSN 1424-8220, Vol. 22, no 10Article in journal (Refereed) Published
Abstract [en]

Laser beam welding offers high productivity and relatively low heat input and is one key enabler for efficient manufacturing of sandwich constructions. However, the process is sensitive to how the laser beam is positioned with regards to the joint, and even a small deviation of the laser beam from the correct joint position (beam offset) can cause severe defects in the produced part. With tee joints, the joint is not visible from top side, therefore traditional seam tracking methods are not applicable since they rely on visual information of the joint. Hence, there is a need for a monitoring system that can give early detection of beam offsets and stop the process to avoid defects and reduce scrap. In this paper, a monitoring system using a spectrometer is suggested and the aim is to find correlations between the spectral emissions from the process and beam offsets. The spectrometer produces high dimensional data and it is not obvious how this is related to the beam offsets. A machine learning approach is therefore suggested to find these correlations. A multi-layer perceptron neural network (MLPNN), support vector machine (SVM), learning vector quantization (LVQ), logistic regression (LR), decision tree (DT) and random forest (RF) were evaluated as classifiers. Feature selection by using random forest and non-dominated sorting genetic algorithm II (NSGAII) was applied before feeding the data to the classifiers and the obtained results of the classifiers are compared subsequently. After testing different offsets, an accuracy of 94% was achieved for real-time detection of the laser beam deviations greater than 0.9 mm from the joint center-line.

Place, publisher, year, edition, pages
MDPI, 2022
Keywords
laser beam offset; feature selection; laser beam welding; machine learning; spectrometer; tee joint
National Category
Bioinformatics and Systems Biology
Research subject
Production Technology
Identifiers
urn:nbn:se:hv:diva-18671 (URN)10.3390/s22103881 (DOI)000803647200001 ()35632290 (PubMedID)2-s2.0-85130378549 (Scopus ID)
Funder
Knowledge Foundation, 20170315
Available from: 2022-06-28 Created: 2022-06-28 Last updated: 2024-04-12
Noori Rahim Abadi, S. M., Hagqvist, P., Sikström, F. & Choquet, I. (2022). CFD-Based Feasibility Study of Laser-Directed Energy Deposition With a Metal Wire for On-Orbit Manufacturing. Frontiers in Space Technologies, 3, 1-13, Article ID 880012.
Open this publication in new window or tab >>CFD-Based Feasibility Study of Laser-Directed Energy Deposition With a Metal Wire for On-Orbit Manufacturing
2022 (English)In: Frontiers in Space Technologies, E-ISSN 2673-5075, Vol. 3, p. 1-13, article id 880012Article in journal (Refereed) Published
Abstract [en]

Additive manufacturing of parts on-site in space requires investigating the feasibility ofadapting to zero-gravity and near-vacuum conditions, a technology applied today on Earthat standard conditions. While a few studies have been conducted for powder bed fusion, afeasibility study remains to be explored for direct energy deposition using a laser beam anda metal wire. This is the purpose of this study, which is conducted using a modelingapproach based on computational fluid dynamics. The simulation model developedincludes melting, re-solidification, vaporization, prediction of beam energy absorptionas a function of the local surface temperature and curvature, ray tracing, tracking of freesurface deformation and metal transfer, and wire-resistive heating. The study is carried outby starting from process parameters suited for stable on-Earth metal deposition. Theseconditions were also studied experimentally to validate the simulation model, leading tosatisfactorily results. A total of three other test cases with ambient pressure lowered downto near-vacuum and/or gravitation down to zero are investigated. It is found that,compared to on-Earth conditions, in-space conditions can induce vaporization of themetal alloy that is large enough to result in a curvature of the melt pool free surface but toosmall to lead to the formation of a keyhole. The in-space conditions can also modify theforce balance at the liquid melt bridge between the wire and the melt pool, leading to smallchanges in the curvature and temperature field at the free surface of the wire tip. Among theobserved consequences are a small increase of the melt pool length and a small elevationof the bead height. More importantly, for process control, changing to in-space conditionsmight also affect the stability of the process, which could be assessed through the width ofthe liquid metal bridge. However, by using appropriate process control to maintain acontinuous liquid metal bridge, it is concluded that direct energy deposition of metal usinga laser and a wire could be used for manufacturing metal parts in-space in a temperedatmosphere.

Place, publisher, year, edition, pages
Frontiers Media S.A., 2022
Keywords
LDEDw, ambient pressure, gravity, metal deposition, melt pool simulation, OpenFOAM
National Category
Manufacturing, Surface and Joining Technology
Research subject
Production Technology
Identifiers
urn:nbn:se:hv:diva-19031 (URN)10.3389/frspt.2022.880012 (DOI)001188287500001 ()
Note

This research work is supported by grants from the SwedishKnowledge Foundation projects AdOpt (20170315) and SAMw(20170060), which is gratefully acknowledged.

Available from: 2022-08-10 Created: 2022-08-10 Last updated: 2024-04-12Bibliographically approved
Aryal, P., Sikström, F., Nilsson, H. & Choquet, I. (2022). Comparative study of the main electromagnetic models applied to melt pool prediction with gas metal arc: Effect on flow, ripples from drop impact, and geometry. International Journal of Heat and Mass Transfer, 194, Article ID 123068.
Open this publication in new window or tab >>Comparative study of the main electromagnetic models applied to melt pool prediction with gas metal arc: Effect on flow, ripples from drop impact, and geometry
2022 (English)In: International Journal of Heat and Mass Transfer, ISSN 0017-9310, E-ISSN 1879-2189, Vol. 194, article id 123068Article in journal (Refereed) Published
Abstract [en]

The present work concerns the electromagnetic force models in computational fluid dynamics simulations of melt pools produced with electric arcs. These are commonly applied to gas metal arcs with metal transfer, in welding and additive manufacturing. Metal drop impact on the melt pool is thus included in this study. The electromagnetic force models applied in literature use either numerical solutions of Poisson equations or one of the two analytical models developed by Kou and Sun, or Tsao and Wu. These models rely on assumptions for which the effect on the melt pool predictions remains to be understood. The present work thoroughly investigates those assumptions and their effects. It has been supported by dedicated experimental tests that did provide estimates of unknown model parameters and validation data. The obtained results show that the assumptions that fundamentally distinguish these three models change the electromagnetic force, including the relation between its components. These changes, which can also be spatially non-uniform, are large. As a result, these models lead to significantly different recirculation flow pattern, thermal convection, melt pool morphology, bead dimensions, and free surface response to the metal transfer. We conclude by proposing conditions in which each of these models is suited or questionable.

Place, publisher, year, edition, pages
Elsevier, 2022
Keywords
Maxwell electromagnetic force model, Kou and Sun model, Tsao and Wu model, Metal transfer, Molten pool, Free surface oscillation, Gas metal arc
National Category
Manufacturing, Surface and Joining Technology
Research subject
Production Technology
Identifiers
urn:nbn:se:hv:diva-19030 (URN)10.1016/j.ijheatmasstransfer.2022.123068 (DOI)001125861400004 ()2-s2.0-85131103929 (Scopus ID)
Funder
European CommissionEU, Horizon Europe
Note

CC BY-NC-ND license

Available from: 2022-08-10 Created: 2022-08-10 Last updated: 2024-04-12Bibliographically approved
Mi, Y., Mahade, S., Sikström, F., Choquet, I., Joshi, S. V. & Ancona, A. (2022). Conduction mode laser welding with beam shaping using a deformable mirror. Optics and Laser Technology, 148
Open this publication in new window or tab >>Conduction mode laser welding with beam shaping using a deformable mirror
Show others...
2022 (English)In: Optics and Laser Technology, ISSN 0030-3992, E-ISSN 1879-2545, Vol. 148Article in journal (Refereed) Published
Abstract [en]

This study explores the possibility of tailoring the fusion zone in conduction mode laser welding using a deformable mirror for beam shaping of multi-kilowatt continuous wave laser sources. Three power density distributions were shaped and used in bead on plate welding of Ti64 plates in conduction mode at three travel speeds. The effect on melt pool free surface geometry, cross section, microstructure and hardness profiles was measured and studied. It is shown that the geometry of the melt pool can be modified using a deformable mirror. A narrower and longer melt pool or a wider, shorter and shallower one were indeed obtained forming Gaussian-elliptical power density distributions oriented along and transverse to the travel direction, respectively. The latter distribution could be a favourable option for laser beam additive manufacturing as it could improve process efficiency while reducing remelting of the previous layer. This system has also a promising potential for adaptive process control since it could change fundamentally the beam shape at a rate faster than 10 ms. 

Place, publisher, year, edition, pages
Elsevier Ltd, 2022
Keywords
Adaptive control systems; Continuous wave lasers; Deformation; Gaussian beams; Lakes; Laser beam welding; Laser beams; Laser mirrors; Microstructure, Beam-shaping; Conduction mode; Conduction mode laser welding; Conduction mode welding; Deformable mirrors; Fusion zone geometry; Fusion zones; Melt pool; Melt pool geometry; Power density distributions, Geometry
National Category
Manufacturing, Surface and Joining Technology
Research subject
Production Technology
Identifiers
urn:nbn:se:hv:diva-17945 (URN)10.1016/j.optlastec.2021.107718 (DOI)000788245300001 ()2-s2.0-85120819958 (Scopus ID)
Funder
Knowledge Foundation, 20170315
Available from: 2022-03-07 Created: 2022-03-07 Last updated: 2024-04-12
Organisations
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0001-5734-294X

Search in DiVA

Show all publications