{ "types" : { "Bookmark" : { "pluralLabel" : "Bookmarks" }, "Publication" : { "pluralLabel" : "Publications" }, "GoldStandardPublication" : { "pluralLabel" : "GoldStandardPublications" }, "GoldStandardBookmark" : { "pluralLabel" : "GoldStandardBookmarks" }, "Tag" : { "pluralLabel" : "Tags" }, "User" : { "pluralLabel" : "Users" }, "Group" : { "pluralLabel" : "Groups" }, "Sphere" : { "pluralLabel" : "Spheres" } }, "properties" : { "count" : { "valueType" : "number" }, "date" : { "valueType" : "date" }, "changeDate" : { "valueType" : "date" }, "url" : { "valueType" : "url" }, "id" : { "valueType" : "url" }, "tags" : { "valueType" : "item" }, "user" : { "valueType" : "item" } }, "items" : [ { "type" : "Publication", "id" : "https://puma.ub.uni-stuttgart.de/bibtex/263218596dc109b8323e4d89fb7dd5d2b/dtraunecker", "tags" : [ "diagnostics","myown","processmonitoring","pyrometer" ], "intraHash" : "63218596dc109b8323e4d89fb7dd5d2b", "interHash" : "876cfacf201b8442b155a5876a058c31", "label" : "Improving pyrometric temperature measurements for quality monitoring of laser processes", "user" : "dtraunecker", "description" : "", "date" : "2025-07-03 08:39:37", "changeDate" : "2025-07-03 08:39:37", "count" : 2, "pub-type": "presentation", "year": "2025", "url": "", "author": [ "David Traunecker","Michael Jarwitz","Andreas Michalowski" ], "authors": [ {"first" : "David", "last" : "Traunecker"}, {"first" : "Michael", "last" : "Jarwitz"}, {"first" : "Andreas", "last" : "Michalowski"} ], "abstract": "Pyrometric temperature measurements are essential for quality monitoring of laser processes, but still face some major challenges. Temperatures usually need to be measured with high accuracy and high spatial resolution due to the typically small process scales of laser processes. However, the temperature accuracy is affected by the angle-dependent emissivity, which can lead to incorrect temperature measurements if the local inclination angle changes, and the spatial resolution is limited by the measurement spot size, leading to reduced spatial resolutions for larger spots. \r\nThis contribution addresses these issues and presents a method to correct the angle-dependent emissivity by simultaneously measuring surface temperature and geometry, and a method to increase the spatial resolution by compensating for the effect of the transfer function of the system, caused by the size of the measurement spot, using a reconstruction algorithm. The results show good agreement with reference measurements, demonstrating the effectiveness of the proposed methods.", "eventtitle" : "Laser in Manufacturing (LiM)", "venue" : "Munich, Germany", "language" : "english", "eventdate" : "23 June - 26 June 2025", "bibtexKey": "traunecker2025improving" } , { "type" : "Publication", "id" : "https://puma.ub.uni-stuttgart.de/bibtex/223fc85dbd169b65df0c80dab133f6b46/dtraunecker", "tags" : [ "Copper","Diagnostics","Pyrometer","myown","peer","processmonitoring" ], "intraHash" : "23fc85dbd169b65df0c80dab133f6b46", "interHash" : "766872e2369a90e6e4abdaf4e905598d", "label" : "Correcting the Influence of the Angle-Dependent Emissivity on Pyrometric Temperature Measurements for Laser Processes", "user" : "dtraunecker", "description" : "", "date" : "2025-02-04 10:45:10", "changeDate" : "2025-02-04 10:45:10", "count" : 3, "pub-type": "article", "journal": "Lasers in Manufacturing and Materials Processing", "year": "2025", "url": "https://doi.org/10.1007/s40516-025-00279-8", "author": [ "David Traunecker","Michael Jarwitz","Andreas Michalowski" ], "authors": [ {"first" : "David", "last" : "Traunecker"}, {"first" : "Michael", "last" : "Jarwitz"}, {"first" : "Andreas", "last" : "Michalowski"} ], "abstract": "Pyrometric temperature measurements, commonly used for quality assurance in laser processes, face a significant challenge due to the angle-dependence of the emissivity, as the local geometry can vary significantly during laser processing. If the emissivity changes during the measurement due to a change in the local inclination angle, this can lead to incorrect temperature measurements for a measurement in single-color mode. Therefore, this paper presents an approach to correct the influence of the angle-dependent emissivity on the pyrometric temperature measurements by simultaneously measuring the surface temperature and the geometry. The approach is demonstrated on test samples made of copper with a defined geometry. The corrected temperatures are in good agreement with a reference measurement for all samples tested, showing that the correction was successful and that the influence of the angle-dependent emissivity can be compensated.", "issn" : "2196-7237", "doi" : "10.1007/s40516-025-00279-8", "bibtexKey": "Traunecker.2025.Correcting" } , { "type" : "Publication", "id" : "https://puma.ub.uni-stuttgart.de/bibtex/2f77c64411286e0752fddac4b733339bc/dtraunecker", "tags" : [ "copper","diagnostics","myown","processmonitoring","pyrometer" ], "intraHash" : "f77c64411286e0752fddac4b733339bc", "interHash" : "e0960e6b8b0a93d4c424736c59c5d902", "label" : "Influence of geometry variations during pyrometric temperature measurement in laser material processing", "user" : "dtraunecker", "description" : "", "date" : "2024-09-20 11:56:11", "changeDate" : "2024-09-20 11:56:11", "count" : 5, "pub-type": "presentation", "year": "2024", "url": "", "author": [ "David Traunecker","Michael Jarwitz","Andreas Michalowski" ], "authors": [ {"first" : "David", "last" : "Traunecker"}, {"first" : "Michael", "last" : "Jarwitz"}, {"first" : "Andreas", "last" : "Michalowski"} ], "abstract": "Pyrometric temperature measurements, essential for quality assurance in laser processing, are challenged by the angular dependence of emissivity with varying local geometries. Therefore, this contribution presents investigations on the influence of geometry variations on pyrometric temperature measurements for geometry variations at different measurement positions and within the measurement spot.\r\n\r\nFor this, laser-heated copper samples with chamfers are used and the measurement spot of the pyrometer is moved over the edge of the chamfer to cover different geometric areas. Three chamfer angles and three measurement spot sizes were examined. In addition, a theoretical calculation has been performed and compared with the experimental results. The study shows the significant influence of geometry variations on the pyrometric temperature measurement.", "eventtitle" : "13th CIRP Conference on Photonic Technologies [LANE 2024]", "venue" : "Fürth, Germany", "language" : "englisch", "eventdate" : "15. \u2013 19. September 2024", "bibtexKey": "Traunecker_2024" } , { "type" : "Publication", "id" : "https://puma.ub.uni-stuttgart.de/bibtex/22734dd05529c6289ddae23c73195e667/dtraunecker", "tags" : [ "copper","diagnostics","myown","peer","processmonitoring","pyrometer" ], "intraHash" : "2734dd05529c6289ddae23c73195e667", "interHash" : "e0960e6b8b0a93d4c424736c59c5d902", "label" : "Influence of geometry variations during pyrometric temperature measurement in laser material processing", "user" : "dtraunecker", "description" : "", "date" : "2024-09-20 11:51:42", "changeDate" : "2024-09-20 11:58:06", "count" : 5, "pub-type": "inproceedings", "journal": "Procedia CIRP","publisher":"Elsevier BV", "year": "2024", "url": "http://dx.doi.org/10.1016/j.procir.2024.08.170", "author": [ "David Traunecker","Michael Jarwitz","Andreas Michalowski" ], "authors": [ {"first" : "David", "last" : "Traunecker"}, {"first" : "Michael", "last" : "Jarwitz"}, {"first" : "Andreas", "last" : "Michalowski"} ], "volume": "124","pages": "540\u2013543","abstract": "Pyrometric temperature measurements, essential for quality assurance in laser processing, are challenged by the angular dependence of emissivity with varying local geometries. Therefore, this contribution presents investigations on the influence of geometry variations on pyrometric temperature measurements for geometry variations at different measurement positions and within the measurement spot.\r\n\r\nFor this, laser-heated copper samples with chamfers are used and the measurement spot of the pyrometer is moved over the edge of the chamfer to cover different geometric areas. Three chamfer angles and three measurement spot sizes were examined. In addition, a theoretical calculation has been performed and compared with the experimental results. The study shows the significant influence of geometry variations on the pyrometric temperature measurement.", "issn" : "2212-8271", "doi" : "10.1016/j.procir.2024.08.170", "bibtexKey": "Traunecker_2024" } , { "type" : "Publication", "id" : "https://puma.ub.uni-stuttgart.de/bibtex/2a94544f51fc55a45b4db93dc2a197894/dtraunecker", "tags" : [ "Diagnostics","Laser","ProcessMonitoring","Simulation","Welding","X-ray","YbYAG","myown" ], "intraHash" : "a94544f51fc55a45b4db93dc2a197894", "interHash" : "cf86e0b2550bc9741cd3bc8585521492", "label" : "Detection of pores during laser beam welding of AlMg3 using the temperature field", "user" : "dtraunecker", "description" : "", "date" : "2024-05-08 14:25:02", "changeDate" : "2024-05-08 14:25:02", "count" : 4, "pub-type": "presentation", "year": "2022", "url": "", "author": [ "David Traunecker","Michael Haas","Michael Jarwitz","Thomas Graf" ], "authors": [ {"first" : "David", "last" : "Traunecker"}, {"first" : "Michael", "last" : "Haas"}, {"first" : "Michael", "last" : "Jarwitz"}, {"first" : "Thomas", "last" : "Graf"} ], "abstract": "To achieve sustainable development in today's production facilities, quality assurance of manufacturing processes, such as laser welding is very important. In particular, online monitoring for direct detection of defective products is especially important. To develop a method for detecting pores during the process, this paper investigates the influence of pores on the temperature field during laser beam welding of AlMg3. Numerical simulations were carried out to theoretically investigate the influence of the pores in the weld seam on the temperature field and experiments were carried out to validate the simulations. The simulations show a clear influence of the pores on the temperature field, making the measurement of the temperature field suitable as a detection method. The detection of the pores from the measured thermal radiation turned out to be difficult because of the huge influence of the seam surface geometry on the emissivity. Especially for an automatic data evaluation, further research on sophisticated evaluation algorithms is required.", "eventtitle" : "ICALEO", "venue" : "Orlando, Florida, United States", "language" : "englisch", "eventdate" : "16 Oktober - 20 Oktober 2022", "bibtexKey": "traunecker2022detection" } , { "type" : "Publication", "id" : "https://puma.ub.uni-stuttgart.de/bibtex/21b35cfad9aaf6fa8f6a54a2dc774f836/dtraunecker", "tags" : [ "diagnostics","hardening","laser","myown","processmonitoring","pyrometer","steel","welding","ybyag" ], "intraHash" : "1b35cfad9aaf6fa8f6a54a2dc774f836", "interHash" : "79ec335cd4437d845d148345c5b8f959", "label" : "In-process determination of the local hardness during laser beam welding of steel", "user" : "dtraunecker", "description" : "", "date" : "2024-05-08 13:51:03", "changeDate" : "2024-05-08 13:51:03", "count" : 2, "pub-type": "presentation", "year": "2023", "url": "", "author": [ "David Traunecker","Michael Jarwitz","Thomas Graf","Andreas Michalowski" ], "authors": [ {"first" : "David", "last" : "Traunecker"}, {"first" : "Michael", "last" : "Jarwitz"}, {"first" : "Thomas", "last" : "Graf"}, {"first" : "Andreas", "last" : "Michalowski"} ], "abstract": "Due to the increasing variety of products and the demand for a sustainable production, flexible production systems are required that can work productively and sustainably from batch-size 1 onwards. This requires flexible and in-process capable quality assurance of the processes to be able to detect defective parts as soon as possible.\r\nOne important quality feature is the hardness, which can be affected during laser beam welding of metals. Usually, the hardness has to be determined post-process, often requiring destructive testing, which is unwanted for small batch sizes and a sustainable use of resources. Therefore, this contribution presents a method for the spatially resolved in-process determination of the hardness. \r\nThe resulting hardness depends on the cooling rate of the solidified metal during the process [1], and this relation was utilized for the in-process determination of the hardness. The cooling process, in turn, can be described by the heat loss coefficient which can be used as a simplified measure of the cooling rate. Therefore, the cooling curves were determined spatially resolved during the welding process using a scanning pyrometer, and the corresponding heat loss coefficients were determined from these cooling curves. Trials with different process parameters were carried out to investigate the correlation between the heat loss coefficient and the hardness, which was determined post-process with indentation measurements. The results show a correlation between the heat loss coefficient and the measured hardness with higher values of the heat loss coefficient coinciding with higher hardness values for each parameter set. Therefore, using the heat loss coefficient proved to be a promising approach for an in-process determination of the local hardness during laser welding of steel.", "eventtitle" : "International Conference on Advanced Joining Processes", "venue" : "Braga, Portugal", "language" : "englisch", "eventdate" : "19. \u2013 20. Oktober 2023", "bibtexKey": "traunecker2023inprocess" } , { "type" : "Publication", "id" : "https://puma.ub.uni-stuttgart.de/bibtex/23c8df5a1fe0b88ea8d7061cf332c904a/dtraunecker", "tags" : [ "diagnostics","hardening","laser","myown","processmonitoring","pyrometer","steel","welding","ybyag" ], "intraHash" : "3c8df5a1fe0b88ea8d7061cf332c904a", "interHash" : "dd1713d591de18da325a26e53a9764e6", "label" : "Online determination of the local hardness during laser beam welding of steel", "user" : "dtraunecker", "description" : "", "date" : "2024-05-08 13:42:07", "changeDate" : "2024-05-08 13:42:07", "count" : 4, "pub-type": "presentation", "year": "2023", "url": "", "author": [ "David Traunecker","Michael Jarwitz","Andreas Michalowski","Thomas Graf" ], "authors": [ {"first" : "David", "last" : "Traunecker"}, {"first" : "Michael", "last" : "Jarwitz"}, {"first" : "Andreas", "last" : "Michalowski"}, {"first" : "Thomas", "last" : "Graf"} ], "abstract": "Due to the increasing product variety, flexible production facilities are required that can already work productively from batch-size 1 onwards. This requires flexible and online-capable quality assurance of the processes to be able to detect defective parts as soon as possible. One important quality feature in laser welding is the resulting hardness, which usually must be determined post-process. In this paper, a method for the spatially resolved online determination of the hardness is presented at the example of laser welding of mild steel. The dependence of the hardness on the cooling rate was utilized for this purpose. Therefore, the cooling curves were determined spatially resolved during the welding process using a scanning pyrometer and the heat loss coefficient was determined from these cooling curves as a measure of the cooling rate. The corresponding local hardness was determined post-process. The results show a correlation between the local hardness values and the local heat loss coefficients within a set of process parameters, making this a promising approach for the spatially resolved online determination of the hardness.", "eventtitle" : "Lasers in Manufacturing", "venue" : "Munich, Germany", "language" : "englisch", "eventdate" : "26. \u2013 29. Juni 2023", "bibtexKey": "traunecker2023online" } , { "type" : "Publication", "id" : "https://puma.ub.uni-stuttgart.de/bibtex/2efeacfdc1a73c303f047d84a396532d3/dtraunecker", "tags" : [ "Diagnostics","Hardening","Laser","ProcessMonitoring","Pyrometer","Steel","Welding","YbYAG","myown" ], "intraHash" : "efeacfdc1a73c303f047d84a396532d3", "interHash" : "dd1713d591de18da325a26e53a9764e6", "label" : "Online determination of the local hardness during laser beam\r\nwelding of steel", "user" : "dtraunecker", "description" : "", "date" : "2023-09-28 14:39:35", "changeDate" : "2023-09-28 14:42:07", "count" : 4, "pub-type": "inproceedings", "year": "2023", "url": "", "author": [ "David Traunecker","Michael Jarwitz","Andreas Michalowski","Thomas Graf" ], "authors": [ {"first" : "David", "last" : "Traunecker"}, {"first" : "Michael", "last" : "Jarwitz"}, {"first" : "Andreas", "last" : "Michalowski"}, {"first" : "Thomas", "last" : "Graf"} ], "abstract": "Due to the increasing product variety, flexible production facilities are required that can already work productively from\r\nbatch-size 1 onwards. This requires flexible and online-capable quality assurance of the processes to be able to detect\r\ndefective parts as soon as possible.\r\nOne important quality feature in laser welding is the resulting hardness, which usually must be determined post-process.\r\nIn this paper, a method for the spatially resolved online determination of the hardness is presented at the example of\r\nlaser welding of mild steel. The dependence of the hardness on the cooling rate was utilized for this purpose.\r\nTherefore, the cooling curves were determined spatially resolved during the welding process using a scanning pyrometer\r\nand the heat loss coefficient was determined from these cooling curves as a measure of the cooling rate. The\r\ncorresponding local hardness was determined post-process. The results show a correlation between the local hardness\r\nvalues and the local heat loss coefficients within a set of process parameters, making this a promising approach for the\r\nspatially resolved online determination of the hardness.", "eventtitle" : "Lasers in Manufacturing", "venue" : "Munich, Germany", "language" : "englisch", "eventdate" : "26. \u2013 29. Juni 2023", "bibtexKey": "david2023online" } , { "type" : "Publication", "id" : "https://puma.ub.uni-stuttgart.de/bibtex/2f4c7e2cac1740398d3e04fcc893ba0d2/dtraunecker", "tags" : [ "Aluminium","Diagnostics","Laser","ProcessMonitoring","Simulation","Welding","X-ray","YbYAG","myown" ], "intraHash" : "f4c7e2cac1740398d3e04fcc893ba0d2", "interHash" : "cf86e0b2550bc9741cd3bc8585521492", "label" : "Detection of pores during laser beam welding of AlMg3 using the temperature field", "user" : "dtraunecker", "description" : "", "date" : "2023-01-09 13:01:36", "changeDate" : "2023-09-28 14:31:00", "count" : 4, "pub-type": "inproceedings", "year": "2022", "url": "", "author": [ "David Traunecker","Michael Haas","Michael Jarwitz","Thomas Graf" ], "authors": [ {"first" : "David", "last" : "Traunecker"}, {"first" : "Michael", "last" : "Haas"}, {"first" : "Michael", "last" : "Jarwitz"}, {"first" : "Thomas", "last" : "Graf"} ], "abstract": "To achieve sustainable development in today's\r\nproduction facilities, quality assurance of\r\nmanufacturing processes, such as laser welding is very\r\nimportant. In particular, online monitoring for direct\r\ndetection of defective products is especially important.\r\nTo develop a method for detecting pores during the\r\nprocess, this paper investigates the influence of pores on\r\nthe temperature field during laser beam welding of\r\nAlMg3.\r\nNumerical simulations were carried out to theoretically\r\ninvestigate the influence of the pores in the weld seam\r\non the temperature field and experiments were carried\r\nout to validate the simulations.\r\nThe simulations show a clear influence of the pores on\r\nthe temperature field, making the measurement of the\r\ntemperature field suitable as a detection method. The\r\ndetection of the pores from the measured thermal\r\nradiation turned out to be difficult because of the huge\r\ninfluence of the seam surface geometry on the\r\nemissivity. Especially for an automatic data evaluation,\r\nfurther research on sophisticated evaluation algorithms\r\nis required.", "eventtitle" : "ICALEO", "venue" : "Orlando, Florida, United States", "language" : "englisch", "eventdate" : "16 Oktober - 20 Oktober 2022", "bibtexKey": "Traunecker.2022.Detection" } ] }