In Situ Monitoring and Control of Laser-Directed Energy Deposition with Wire – Part 2: Geometry and Hardness Modeling and Closed-Loop Control

In Situ Monitoring and Control of Laser-Directed Energy Deposition with Wire – Part 2: Geometry and Hardness Modeling and Closed-Loop Control | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article In Situ Monitoring and Control of Laser-Directed Energy Deposition with Wire – Part 2: Geometry and Hardness Modeling and Closed-Loop Control Mostafa Rahmani Dehaghani, Kevin Oldknow, Morgan Nilsen, Farzaneh Farhang Mehr, and 4 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-7736701/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 09 Feb, 2026 Read the published version in The International Journal of Advanced Manufacturing Technology → Version 1 posted 5 You are reading this latest preprint version Abstract Laser-directed energy deposition with wire (L-DED/W) has gained attention due to its high deposition and utilization rates. However, components fabricated using this method often exhibit geometric inaccuracies and anisotropic mechanical properties, primarily stemming from unstable deposition dynamics and complex thermomechanical phenomena. To enable in situ monitoring and closed-loop control of final qualities such as geometry and hardness—which cannot be directly measured during deposition—this study employs the parameter–signature–quality (PSQ) framework. This paper, the second in a two-part series, builds upon the experimental foundation and insights developed in the first part to complete the steps toward real-time multi-input multi-output (MIMO) closed-loop control of the L-DED/W process, targeting simultaneous regulation of geometric accuracy and hardness. First, a high-fidelity MIMO system identification model is developed using a long-short-term-memory network, capturing the nonlinear and dynamic relationships between process parameters (power and speed) and melt pool signatures (width, size, and length) with high accuracy. Second, hardness is classified using a combination of process parameters and melt pool signatures, achieving strong predictive performance suitable for real-time application within the PSQ framework. Finally, a fuzzy logic controller is integrated with the PSQ models to achieve closed-loop MIMO control, demonstrating effective regulation of melt pool geometry while maximizing the likelihood of achieving high hardness, even under process uncertainties for real-world production. This study presents the first successful integration of fuzzy logic control and the PSQ framework for simultaneous control of both mechanical and geometric properties in a directed energy deposition process. It contributes to the broader field by demonstrating the feasibility of in situ regulation of otherwise unmeasurable final qualities and highlights fuzzy logic control as a flexible and computationally efficient alternative for multi-objective control in additive manufacturing. Laser Directed Energy Deposition with Wire In Situ Monitoring Long-Short-Term-Memory Closed-loop Control Multi-objective Control Fuzzy Logic Control Full Text Cite Share Download PDF Status: Published Journal Publication published 09 Feb, 2026 Read the published version in The International Journal of Advanced Manufacturing Technology → Version 1 posted Editorial decision: Major Revisions Needed 20 Nov, 2025 Reviewers agreed at journal 06 Oct, 2025 Reviewers invited by journal 03 Oct, 2025 Editor assigned by journal 02 Oct, 2025 First submitted to journal 30 Sep, 2025 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-7736701","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":524270682,"identity":"4dcaf3f3-3a4f-4d59-990c-13788abfc990","order_by":0,"name":"Mostafa Rahmani Dehaghani","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAABFUlEQVRIiWNgGAWjYNACGyCWADEMbJj5QXRCAV71jA0MaXAtaeySDSAtBkRrYTjMb3AArBe3et329ucPfiTY5fPP7k78XFBwWNr4/OrEDw8MGOT5xQ5g1WJ25oxhY09CsuWMO2c3S88wSDc2u/F2swTQYYYzZydg13Ijh7GB9wezAcON3A3SPAbWyWY3zm4AaUkwuI1LS/rDxj8J9QbyN3I3/+YxYK7fPOPs5h/4tSQYNvMkHDYwuJG7DWiLM7MBf+82/LYA/TJbJuG4gSFQizWPQRqzxA3ebRYJBhK4/XK8/cHHNwnVBnJAh93m+QOMyv6zm2/+qLCR55fGrgULkACrlCBWOQjwHyBF9SgYBaNgFIwAAACIemMWKEl7ZQAAAABJRU5ErkJggg==","orcid":"https://orcid.org/0000-0003-4618-0302","institution":"Simon Fraser University Faculty of Science","correspondingAuthor":true,"prefix":"","firstName":"Mostafa","middleName":"Rahmani","lastName":"Dehaghani","suffix":""},{"id":524270683,"identity":"c6599795-ff54-4328-b886-99d5e15be33b","order_by":1,"name":"Kevin Oldknow","email":"","orcid":"","institution":"","correspondingAuthor":false,"prefix":"","firstName":"Kevin","middleName":"","lastName":"Oldknow","suffix":""},{"id":524270684,"identity":"3489ec44-7cd3-4a8d-acfd-d7db4063eb88","order_by":2,"name":"Morgan Nilsen","email":"","orcid":"","institution":"","correspondingAuthor":false,"prefix":"","firstName":"Morgan","middleName":"","lastName":"Nilsen","suffix":""},{"id":524270685,"identity":"dd4dcf59-dd04-40c3-8b24-e8d29d98d96b","order_by":3,"name":"Farzaneh Farhang Mehr","email":"","orcid":"","institution":"","correspondingAuthor":false,"prefix":"","firstName":"Farzaneh","middleName":"Farhang","lastName":"Mehr","suffix":""},{"id":524270686,"identity":"bc329fc2-2da3-4bb3-82a9-251afb8a79b5","order_by":4,"name":"Yifan Tang","email":"","orcid":"","institution":"","correspondingAuthor":false,"prefix":"","firstName":"Yifan","middleName":"","lastName":"Tang","suffix":""},{"id":524270687,"identity":"d9fdaa97-74c8-4954-a9c4-34d8b7eff4e5","order_by":5,"name":"Nguyen Gia Hien Vu","email":"","orcid":"","institution":"","correspondingAuthor":false,"prefix":"","firstName":"Nguyen","middleName":"Gia Hien","lastName":"Vu","suffix":""},{"id":524270688,"identity":"d64bca77-06b9-496b-bb82-5c521aeed2de","order_by":6,"name":"Ke Wang","email":"","orcid":"","institution":"","correspondingAuthor":false,"prefix":"","firstName":"Ke","middleName":"","lastName":"Wang","suffix":""},{"id":524270689,"identity":"a4c573ff-d078-4990-8357-27e2418cccec","order_by":7,"name":"G. Gary Wang","email":"","orcid":"","institution":"","correspondingAuthor":false,"prefix":"","firstName":"G.","middleName":"Gary","lastName":"Wang","suffix":""}],"badges":[],"createdAt":"2025-09-28 23:44:16","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-7736701/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-7736701/v1","draftVersion":[],"editorialEvents":[{"content":"https://doi.org/10.1007/s00170-026-17618-4","type":"published","date":"2026-02-09T15:59:25+00:00"}],"editorialNote":"","failedWorkflow":false,"files":[{"id":93692379,"identity":"22730795-f4aa-461e-bce1-b9e64bee6dc7","added_by":"auto","created_at":"2025-10-16 14:12:58","extension":"xml","order_by":1,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":11581,"visible":true,"origin":"","legend":"","description":"","filename":"jamtJAMTD2505600.xml","url":"https://assets-eu.researchsquare.com/files/rs-7736701/v1/755fa49cc0f1c626cc8c4967.xml"},{"id":93691083,"identity":"9e5d034e-7703-40a5-9329-d7273b93c6d5","added_by":"auto","created_at":"2025-10-16 14:04:58","extension":"xml","order_by":2,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":964,"visible":true,"origin":"","legend":"","description":"","filename":"JAMTD2505600157376.go.xml","url":"https://assets-eu.researchsquare.com/files/rs-7736701/v1/5016e34d40f8d1421be614a4.xml"},{"id":93691085,"identity":"305c0e80-0cba-4562-8500-0033eca38fd4","added_by":"auto","created_at":"2025-10-16 14:04:58","extension":"xml","order_by":3,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":955,"visible":true,"origin":"","legend":"","description":"","filename":"JAMTD2505600Import.xml","url":"https://assets-eu.researchsquare.com/files/rs-7736701/v1/e625ba9ab08d2f7893a23b7a.xml"},{"id":93691095,"identity":"bad6e843-9751-4e82-a1b8-8c121f09cab4","added_by":"auto","created_at":"2025-10-16 14:04:58","extension":"xml","order_by":4,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":164102,"visible":true,"origin":"","legend":"","description":"","filename":"JAMTD25056000enriched.xml","url":"https://assets-eu.researchsquare.com/files/rs-7736701/v1/18aa29dd022502b453c88964.xml"},{"id":93692380,"identity":"4a51598e-d596-4fb9-bf59-10fbb0e3ba4e","added_by":"auto","created_at":"2025-10-16 14:12:58","extension":"png","order_by":5,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":89578,"visible":true,"origin":"","legend":"","description":"","filename":"floatimage1.png","url":"https://assets-eu.researchsquare.com/files/rs-7736701/v1/72a072c4e22786008bfd9fe8.png"},{"id":93691087,"identity":"997106e5-7e22-4b18-95a0-7c8f7b8dc53c","added_by":"auto","created_at":"2025-10-16 14:04:58","extension":"jpeg","order_by":6,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":274173,"visible":true,"origin":"","legend":"","description":"","filename":"floatimage10.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-7736701/v1/ed2ca60cbac59cd9c3edc259.jpeg"},{"id":93692381,"identity":"4c62e8eb-bc5c-4b8e-b2c8-10ff8e6365a9","added_by":"auto","created_at":"2025-10-16 14:12:58","extension":"emf","order_by":7,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":2218840,"visible":true,"origin":"","legend":"","description":"","filename":"floatimage11.emf","url":"https://assets-eu.researchsquare.com/files/rs-7736701/v1/67c7cf97c35927b12bf01005.emf"},{"id":93691096,"identity":"dddab64f-eef6-40e5-bcba-c2ed7f06e81a","added_by":"auto","created_at":"2025-10-16 14:04:58","extension":"emf","order_by":8,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":1894576,"visible":true,"origin":"","legend":"","description":"","filename":"floatimage12.emf","url":"https://assets-eu.researchsquare.com/files/rs-7736701/v1/d95ef4d28c872045bfa50db2.emf"},{"id":93691098,"identity":"fae44e90-5645-49de-a2e7-b6793f60997e","added_by":"auto","created_at":"2025-10-16 14:04:58","extension":"emf","order_by":9,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":1075760,"visible":true,"origin":"","legend":"","description":"","filename":"floatimage13.emf","url":"https://assets-eu.researchsquare.com/files/rs-7736701/v1/48859f2d49b7bb57a098d8ee.emf"},{"id":93693206,"identity":"c8c17959-afb4-45c5-9b08-2ca6d3da3fa5","added_by":"auto","created_at":"2025-10-16 14:20:58","extension":"png","order_by":10,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":87705,"visible":true,"origin":"","legend":"","description":"","filename":"floatimage2.png","url":"https://assets-eu.researchsquare.com/files/rs-7736701/v1/a56c4f8515ddc30e5e3c03b2.png"},{"id":93694450,"identity":"432793fb-40c9-48a7-9559-06b0fd97964a","added_by":"auto","created_at":"2025-10-16 14:28:58","extension":"jpeg","order_by":11,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":287982,"visible":true,"origin":"","legend":"","description":"","filename":"floatimage3.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-7736701/v1/4c8124348731640cea0e3e7c.jpeg"},{"id":93691097,"identity":"0fe8097b-5c80-4a15-b02b-94abe026724a","added_by":"auto","created_at":"2025-10-16 14:04:58","extension":"emf","order_by":12,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":91268,"visible":true,"origin":"","legend":"","description":"","filename":"floatimage4.emf","url":"https://assets-eu.researchsquare.com/files/rs-7736701/v1/c0982e16ccf4a3f6863d9624.emf"},{"id":93692386,"identity":"43a18d54-e944-49d2-a833-5da6c76e5173","added_by":"auto","created_at":"2025-10-16 14:12:58","extension":"png","order_by":13,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":152831,"visible":true,"origin":"","legend":"","description":"","filename":"floatimage5.png","url":"https://assets-eu.researchsquare.com/files/rs-7736701/v1/1afc30ee39fe3ba6ac4696ce.png"},{"id":93691102,"identity":"257a0411-5b7e-4baa-90f5-55cc7ea84050","added_by":"auto","created_at":"2025-10-16 14:04:58","extension":"png","order_by":14,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":1136272,"visible":true,"origin":"","legend":"","description":"","filename":"floatimage6.png","url":"https://assets-eu.researchsquare.com/files/rs-7736701/v1/d5a48eb1153f025145818912.png"},{"id":93692389,"identity":"8402f799-94bb-4a0f-9fea-3e32531d7990","added_by":"auto","created_at":"2025-10-16 14:12:58","extension":"png","order_by":15,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":242659,"visible":true,"origin":"","legend":"","description":"","filename":"floatimage7.png","url":"https://assets-eu.researchsquare.com/files/rs-7736701/v1/4b40b6a8cb06d3c8ac48a491.png"},{"id":93691105,"identity":"c19722fd-e7ab-408d-ab39-7791c63692a3","added_by":"auto","created_at":"2025-10-16 14:04:58","extension":"png","order_by":16,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":953481,"visible":true,"origin":"","legend":"","description":"","filename":"floatimage8.png","url":"https://assets-eu.researchsquare.com/files/rs-7736701/v1/d612a265cc082090a78d6f23.png"},{"id":93692392,"identity":"ba43cefa-a4f1-49da-8de5-db2c6acf73c8","added_by":"auto","created_at":"2025-10-16 14:12:58","extension":"png","order_by":17,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":180144,"visible":true,"origin":"","legend":"","description":"","filename":"floatimage9.png","url":"https://assets-eu.researchsquare.com/files/rs-7736701/v1/d1ecc0a299481b3b4cf33298.png"},{"id":93693208,"identity":"95182a19-4f44-42eb-adef-38498688e585","added_by":"auto","created_at":"2025-10-16 14:20:58","extension":"png","order_by":18,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":40448,"visible":true,"origin":"","legend":"","description":"","filename":"Onlinefloatimage1.png","url":"https://assets-eu.researchsquare.com/files/rs-7736701/v1/04172404ed1f6a860c1f9a8a.png"},{"id":93692387,"identity":"f1aa8e11-63ba-4ab3-a4ab-df2a882f87e1","added_by":"auto","created_at":"2025-10-16 14:12:58","extension":"png","order_by":19,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":47989,"visible":true,"origin":"","legend":"","description":"","filename":"Onlinefloatimage10.png","url":"https://assets-eu.researchsquare.com/files/rs-7736701/v1/2dafe061b32051b6f15421b7.png"},{"id":93691088,"identity":"d1a95577-aff8-4835-8496-cee5cb0e872a","added_by":"auto","created_at":"2025-10-16 14:04:58","extension":"png","order_by":20,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":19659,"visible":true,"origin":"","legend":"","description":"","filename":"Onlinefloatimage11.png","url":"https://assets-eu.researchsquare.com/files/rs-7736701/v1/247e2439c493ce720032234c.png"},{"id":93693212,"identity":"1fc37fca-c5c3-4961-9d5b-3926376e38f6","added_by":"auto","created_at":"2025-10-16 14:20:58","extension":"png","order_by":21,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":35268,"visible":true,"origin":"","legend":"","description":"","filename":"Onlinefloatimage12.png","url":"https://assets-eu.researchsquare.com/files/rs-7736701/v1/2c42dfc00ee1ffd9bb3ed003.png"},{"id":93694449,"identity":"59cefc16-3331-4228-96f9-ea603e6e73e2","added_by":"auto","created_at":"2025-10-16 14:28:58","extension":"png","order_by":22,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":19540,"visible":true,"origin":"","legend":"","description":"","filename":"Onlinefloatimage13.png","url":"https://assets-eu.researchsquare.com/files/rs-7736701/v1/84671317bbbb0aed9b25fd19.png"},{"id":93693211,"identity":"21df4f79-5d36-4556-af87-85fdb8c92f33","added_by":"auto","created_at":"2025-10-16 14:20:58","extension":"png","order_by":23,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":34198,"visible":true,"origin":"","legend":"","description":"","filename":"Onlinefloatimage2.png","url":"https://assets-eu.researchsquare.com/files/rs-7736701/v1/7aa75511779b13ee13f9da94.png"},{"id":93691109,"identity":"38055b76-840f-47f2-ac5e-3a1a1c067a1f","added_by":"auto","created_at":"2025-10-16 14:04:58","extension":"png","order_by":24,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":49956,"visible":true,"origin":"","legend":"","description":"","filename":"Onlinefloatimage3.png","url":"https://assets-eu.researchsquare.com/files/rs-7736701/v1/4bc97e54939d361425cde4e3.png"},{"id":93691101,"identity":"a7f21abc-c47b-47a3-ad70-92c9d612c00e","added_by":"auto","created_at":"2025-10-16 14:04:58","extension":"png","order_by":25,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":16487,"visible":true,"origin":"","legend":"","description":"","filename":"Onlinefloatimage4.png","url":"https://assets-eu.researchsquare.com/files/rs-7736701/v1/06ba4b7881e4189720ce84b0.png"},{"id":93694451,"identity":"8db5c229-3253-4540-aa69-18540cd4f9d3","added_by":"auto","created_at":"2025-10-16 14:28:58","extension":"png","order_by":26,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":64128,"visible":true,"origin":"","legend":"","description":"","filename":"Onlinefloatimage5.png","url":"https://assets-eu.researchsquare.com/files/rs-7736701/v1/6544fc3b0363ff5dc190b646.png"},{"id":93691114,"identity":"315ef06a-e1dd-4b54-928d-faa3aeb13277","added_by":"auto","created_at":"2025-10-16 14:04:58","extension":"png","order_by":27,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":508554,"visible":true,"origin":"","legend":"","description":"","filename":"Onlinefloatimage6.png","url":"https://assets-eu.researchsquare.com/files/rs-7736701/v1/580780df91bcacab02e3906e.png"},{"id":93691107,"identity":"714ef579-0f06-4b66-ba50-8349af31f24f","added_by":"auto","created_at":"2025-10-16 14:04:58","extension":"png","order_by":28,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":105540,"visible":true,"origin":"","legend":"","description":"","filename":"Onlinefloatimage7.png","url":"https://assets-eu.researchsquare.com/files/rs-7736701/v1/ca0577289ed3f17c96ac52c7.png"},{"id":93691113,"identity":"25caaed9-d813-4687-aaa8-3b81095349a9","added_by":"auto","created_at":"2025-10-16 14:04:58","extension":"png","order_by":29,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":316155,"visible":true,"origin":"","legend":"","description":"","filename":"Onlinefloatimage8.png","url":"https://assets-eu.researchsquare.com/files/rs-7736701/v1/06720bb64f6132efdd7a47fa.png"},{"id":93691110,"identity":"cb43246a-03bd-440d-9416-e0ad8e9a499f","added_by":"auto","created_at":"2025-10-16 14:04:58","extension":"png","order_by":30,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":44492,"visible":true,"origin":"","legend":"","description":"","filename":"Onlinefloatimage9.png","url":"https://assets-eu.researchsquare.com/files/rs-7736701/v1/8de156ae5e2cd00ad5150b50.png"},{"id":93691111,"identity":"15b62b04-701a-49ea-a111-0da8474d643c","added_by":"auto","created_at":"2025-10-16 14:04:58","extension":"xml","order_by":31,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":164132,"visible":true,"origin":"","legend":"","description":"","filename":"JAMTD25056000structuring.xml","url":"https://assets-eu.researchsquare.com/files/rs-7736701/v1/98986a4f7ed1f42cc0e7bada.xml"},{"id":93692393,"identity":"e723d4eb-62ef-477b-90fe-7419b3bb52d9","added_by":"auto","created_at":"2025-10-16 14:12:58","extension":"html","order_by":32,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":175138,"visible":true,"origin":"","legend":"","description":"","filename":"earlyproof.html","url":"https://assets-eu.researchsquare.com/files/rs-7736701/v1/13986d8754a1506376bf66c4.html"},{"id":102786070,"identity":"26cc2755-7224-4b6c-84f4-6083e695b01e","added_by":"auto","created_at":"2026-02-16 16:11:38","extension":"pdf","order_by":1,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":3596655,"visible":true,"origin":"","legend":"","description":"","filename":"MicrostructureandHardnessofDSSUsingPSQP2.pdf","url":"https://assets-eu.researchsquare.com/files/rs-7736701/v1_covered_a73db9a5-9ac4-4d85-8a67-91f54a6eb793.pdf"}],"financialInterests":"","formattedTitle":"In Situ Monitoring and Control of Laser-Directed Energy Deposition with Wire – Part 2: Geometry and Hardness Modeling and Closed-Loop Control","fulltext":[],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":false,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":true,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":true,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"the-international-journal-of-advanced-manufacturing-technology","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"jamt","sideBox":"Learn more about [The International Journal of Advanced Manufacturing Technology](https://www.springer.com/journal/170)","snPcode":"170","submissionUrl":"https://submission.nature.com/new-submission/170/3","title":"The International Journal of Advanced Manufacturing Technology","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false},"keywords":"Laser Directed Energy Deposition with Wire, In Situ Monitoring, Long-Short-Term-Memory, Closed-loop Control, Multi-objective Control, Fuzzy Logic Control","lastPublishedDoi":"10.21203/rs.3.rs-7736701/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-7736701/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eLaser-directed energy deposition with wire (L-DED/W) has gained attention due to its high deposition and utilization rates. However, components fabricated using this method often exhibit geometric inaccuracies and anisotropic mechanical properties, primarily stemming from unstable deposition dynamics and complex thermomechanical phenomena. To enable in situ monitoring and closed-loop control of final qualities such as geometry and hardness\u0026mdash;which cannot be directly measured during deposition\u0026mdash;this study employs the parameter\u0026ndash;signature\u0026ndash;quality (PSQ) framework.\u003c/p\u003e\u003cp\u003eThis paper, the second in a two-part series, builds upon the experimental foundation and insights developed in the first part to complete the steps toward real-time multi-input multi-output (MIMO) closed-loop control of the L-DED/W process, targeting simultaneous regulation of geometric accuracy and hardness. First, a high-fidelity MIMO system identification model is developed using a long-short-term-memory network, capturing the nonlinear and dynamic relationships between process parameters (power and speed) and melt pool signatures (width, size, and length) with high accuracy. Second, hardness is classified using a combination of process parameters and melt pool signatures, achieving strong predictive performance suitable for real-time application within the PSQ framework. Finally, a fuzzy logic controller is integrated with the PSQ models to achieve closed-loop MIMO control, demonstrating effective regulation of melt pool geometry while maximizing the likelihood of achieving high hardness, even under process uncertainties for real-world production.\u003c/p\u003e\u003cp\u003eThis study presents the first successful integration of fuzzy logic control and the PSQ framework for simultaneous control of both mechanical and geometric properties in a directed energy deposition process. It contributes to the broader field by demonstrating the feasibility of in situ regulation of otherwise unmeasurable final qualities and highlights fuzzy logic control as a flexible and computationally efficient alternative for multi-objective control in additive manufacturing.\u003c/p\u003e","manuscriptTitle":"In Situ Monitoring and Control of Laser-Directed Energy Deposition with Wire – Part 2: Geometry and Hardness Modeling and Closed-Loop Control","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-10-16 14:04:53","doi":"10.21203/rs.3.rs-7736701/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Major Revisions Needed","date":"2025-11-20T14:24:20+00:00","index":"","fulltext":""},{"type":"reviewerAgreed","content":"","date":"2025-10-06T15:18:40+00:00","index":0,"fulltext":""},{"type":"reviewersInvited","content":"","date":"2025-10-03T12:48:29+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2025-10-03T01:49:55+00:00","index":"","fulltext":""},{"type":"submitted","content":"The International Journal of Advanced Manufacturing Technology","date":"2025-10-01T01:19:34+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"the-international-journal-of-advanced-manufacturing-technology","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"jamt","sideBox":"Learn more about [The International Journal of Advanced Manufacturing Technology](https://www.springer.com/journal/170)","snPcode":"170","submissionUrl":"https://submission.nature.com/new-submission/170/3","title":"The International Journal of Advanced Manufacturing Technology","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false}}],"origin":"","ownerIdentity":"f137d83b-ac16-4fe7-9076-895c066f7c62","owner":[],"postedDate":"October 16th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[],"tags":[],"updatedAt":"2026-02-16T16:08:20+00:00","versionOfRecord":{"articleIdentity":"rs-7736701","link":"https://doi.org/10.1007/s00170-026-17618-4","journal":{"identity":"the-international-journal-of-advanced-manufacturing-technology","isVorOnly":false,"title":"The International Journal of Advanced Manufacturing Technology"},"publishedOn":"2026-02-09 15:59:25","publishedOnDateReadable":"February 9th, 2026"},"versionCreatedAt":"2025-10-16 14:04:53","video":"","vorDoi":"10.1007/s00170-026-17618-4","vorDoiUrl":"https://doi.org/10.1007/s00170-026-17618-4","workflowStages":[]},"version":"v1","identity":"rs-7736701","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-7736701","identity":"rs-7736701","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}