@article{SchleglTomaselliSchlegletal., author = {Schlegl, Thomas and Tomaselli, Domenico and Schlegl, Stefan and West, Nicolai and Deuse, Jochen}, title = {Automated search of process control limits for fault detection in time series data}, series = {Journal of Process Control}, volume = {117}, journal = {Journal of Process Control}, publisher = {Elsevier}, doi = {10.1016/j.jprocont.2022.07.002}, pages = {52 -- 64}, abstract = {Manually defined control limits remain a common strategy for quality control in manufacturing due to their ease of deployment on the shop floor compared to more advanced data analysis approaches. Despite their continued importance, there is no systematic method of defining these control limits. However, sub-optimal control limits can lead to undetected faults or cause unnecessary interruption to production. This manuscript presents an algorithm that systematizes this manual process into an efficient search task. We conceptualized the search task as a sequence of sub-problems that are based on the conventional steps taken by process experts when defining control limits. This algorithm can be integrated into an expert tool for shop floor personnel to automate the definition of control limits in annotated time series data. We demonstrate the efficacy of the control limits found by our algorithm by comparing them to those manually defined by process experts in real-world process data from the automotive industry. Furthermore, we show that our algorithm generalizes to traditional time series classification problems and achieves state-of-the-art performance on selected benchmark datasets. Our work is the first effort in automating the otherwise manual definition of control limits for fault detection.}, language = {en} } @misc{BeimlerLeisslEbneretal., author = {Beimler, Josef and Leißl, Caroline and Ebner, Lena and Elsner, Michael and M{\"u}hlbauer, Gerhard and Kohlert, Dieter and Schubert, Martin J. W. and Weiß, Andreas P. and Sterner, Michael and Raith, Thomas and Afranseder, Martin and Krapf, Tobias and Mottok, J{\"u}rgen and Siemers, Christian and Großmann, Benjamin and H{\"o}cherl, Johannes and Schlegl, Thomas and Schneider, Ralph and Milaev, Johannes and Rampelt, Christina and Roduner, Christian and Glowa, Christoph and Bachl, Christoph and Schliekmann, Claus and Gnan, Alfons and Grill, Martin and Ruhland, Karl and Piehler, Thomas and Friers, Daniel and Wels, Harald and Pflug, Kenny and Kucera, Markus and Waas, Thomas and Schlachetzki, Felix and Boy, Sandra and Pemmerl, Josef and Leis, Alexander and Welsch, Andreas F.X. and Graf, Franz and Zenger, Gerhard and Volbert, Klaus and Waas, Thomas and Scherzinger, Stefanie and Klettke, Meike and St{\"o}rl, Uta and Heyl, C. and Boldenko, A. and Monkman, Gareth J. and Kujat, Richard and Briem, Ulrich and Hierl, Stefan and Talbot, Sebastian and Schmailzl, Anton and Ławrowski, Robert Damian and Prommesberger, Christian and Langer, Christoph and Dams, Florian and Schreiner, Rupert and Valentino, Piergiorgio and Romano, Marco and Ehrlich, Ingo and Furgiuele, Franco and Gebbeken, Norbert and Eisenried, Michael and Jungbauer, Bastian and Hutterer, Albert and Bauhuber, Michael and Mikrievskij, Andreas and Argauer, Monika and Hummel, Helmut and Lechner, Alfred and Liebetruth, Thomas and Schumm, Michael and Joseph, Saskia and Reschke, Michael and Soska, Alexander and Schroll-Decker, Irmgard and Putzer, Michael and Rasmussen, John and Dendorfer, Sebastian and Weber, Tim and Al-Munajjed, Amir Andreas and Verkerke, Gijsbertus Jacob and Renkawitz, Tobias and Haug, Sonja and Rudolph, Clarissa and Zeitler, Annika and Schaubeck, Simon and Steffens, Oliver and Rechenauer, Christian and Schulz-Brize, Thekla and Fleischmann, Florian and Kusterle, Wolfgang and Beer, Anne and Wagner, Bernd and Neidhart, Thomas}, title = {Forschungsbericht 2013}, editor = {Baier, Wolfgang}, address = {Regensburg}, organization = {Ostbayerische Technische Hochschule Regensburg}, doi = {10.35096/othr/pub-799}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:898-opus4-7990}, pages = {80}, language = {de} } @misc{ScharfenbergMottokArtmannetal., author = {Scharfenberg, Georg and Mottok, J{\"u}rgen and Artmann, Christina and Hobelsberger, Martin and Paric, Ivan and Großmann, Benjamin and Pohlt, Clemens and Wackerbarth, Alena and Pausch, Uli and Heidrich, Christiane and Fadanelli, Martin and Elsner, Michael and P{\"o}cher, Daniel and Pittroff, Lenz and Beer, Stefan and Br{\"u}ckl, Oliver and Haslbeck, Matthias and Sterner, Michael and Thema, Martin and Muggenthaler, Nicole and Lenck, Thorsten and G{\"o}tz, Philipp and Eckert, Fabian and Deubzer, Michael and Stingl, Armin and Simsek, Erol and Kr{\"a}mer, Stefan and Großmann, Benjamin and Schlegl, Thomas and Niedersteiner, Sascha and Berlehner, Thomas and Joblin, Mitchell and Mauerer, Wolfgang and Apel, Sven and Siegmund, Janet and Riehle, Dirk and Weber, Joachim and Palm, Christoph and Zobel, Martin and Al-Falouji, Ghassan and Prestel, Dietmar and Scharfenberg, Georg and Mandl, Roland and Deinzer, Arnulf and Halang, W. and Margraf-Stiksrud, Jutta and Sick, Bernhard and Deinzer, Renate and Scherzinger, Stefanie and Klettke, Meike and St{\"o}rl, Uta and Wiech, Katharina and Kubata, Christoph and Sindersberger, Dirk and Monkman, Gareth J. and Dollinger, Markus and Dembianny, Sven and K{\"o}lbl, Andreas and Welker, Franz and Meier, Matthias and Thumann, Philipp and Swidergal, Krzysztof and Wagner, Marcus and Haug, Sonja and Vernim, Matthias and Seidenst{\"u}cker, Barbara and Weber, Karsten and Arsan, Christian and Schone, Reinhold and M{\"u}nder, Johannes and Schroll-Decker, Irmgard and Dillinger, Andrea Elisabeth and Fuchshofer, Rudolf and Monkman, Gareth J. and Shamonin (Chamonine), Mikhail and Geith, Markus A. and Koch, Fabian and {\"U}hlin, Christian and Schratzenstaller, Thomas and Saßmannshausen, Sean Patrick and Auchter, Eberhard and Kriz, Willy and Springer, Othmar and Thumann, Maria and Kusterle, Wolfgang and Obermeier, Andreas and Udalzow, Anton and Schmailzl, Anton and Hierl, Stefan and Langer, Christoph and Schreiner, Rupert}, title = {Forschungsbericht 2015}, editor = {Baier, Wolfgang}, address = {Regensburg}, organization = {Ostbayerische Technische Hochschule Regensburg}, isbn = {978-3-00-048589-3}, doi = {10.35096/othr/pub-1386}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:898-opus4-13867}, language = {de} } @misc{RueckBierlLechneretal., author = {R{\"u}ck, Thomas and Bierl, Rudolf and Lechner, Alfred and Graf, Antonia and Dams, Florian and Schreiner, Rupert and Auchter, Eberhard and Kriz, Willy and Deubzer, MIchael and Schiller, Frank and Mottok, J{\"u}rgen and Niemetz, Michael and Margull, Ulrich and Hagel, Georg and Utesch, Matthias and Waldherr, Franz and B{\"o}hm, Matthias and Fraunhoffer, Judith and Gardeia, Armin and Schneider, Ralph and Streubel, Janet and Landes, Dieter and Studt, Reimer and Peuker, Dominik and Scharfenberg, Georg and Hook, Christian and Schuster, Dietwald and Ehrlich, Ingo and Dinnebier, Heinrich and Briem, Ulrich and L{\"a}mmlein, Stephan and Koder, Alexander and Bialek, Adam and Genewsky, Axel and Neumeier, Michael and Schlosser, Philipp and Rabl, Hans-Peter and Paule, Matthias and Galster, Christoph and Schiedermeier, Michael and Zwickel, Andreas and Hobmeier, Christoph and Bischoff, Tobias and Rill, Georg and Schaeffer, Thomas and Arbesmeier, Martin and Groß, Andreas and Schlegl, Thomas and Becker, Mark and Senn, Konrad and Schliekmann, Claus and Scholz, Peter and Sippl, Christian and Grill, Martin}, title = {Forschungsbericht 2011 / Hochschule f{\"u}r Angewandte Wissenschaften - Fachhochschule Regensburg}, editor = {Eckstein, Josef}, address = {Regensburg}, organization = {Hochschule f{\"u}r Angewandte Wissenschaften Regensburg}, issn = {1868-3533}, doi = {10.35096/othr/pub-732}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:898-opus4-7321}, language = {de} } @inproceedings{HoecherlNiedersteinerHaugetal., author = {H{\"o}cherl, Johannes and Niedersteiner, Sascha and Haug, Sonja and Pohlt, Clemens and Schlegl, Thomas and Weber, Karsten and Berlehner, Thomas}, title = {Smart Workbench}, series = {2. OTH Clustertagung, 18.01.2017, Regensburg}, booktitle = {2. OTH Clustertagung, 18.01.2017, Regensburg}, language = {de} } @inproceedings{HoecherlNiedersteinerHaugetal., author = {H{\"o}cherl, Johannes and Niedersteiner, Sascha and Haug, Sonja and Pohlt, Clemens and Schlegl, Thomas and Weber, Karsten and Berlehner, Thomas}, title = {Smart Workbench}, series = {2. Transdisziplin{\"a}ren Konferenz "Technische Unterst{\"u}tzungssysteme, die die Menschen wirklich wollen", 12.-13.12.2016, Helmut-Schmidt-Universit{\"a}t, Hamburg}, booktitle = {2. Transdisziplin{\"a}ren Konferenz "Technische Unterst{\"u}tzungssysteme, die die Menschen wirklich wollen", 12.-13.12.2016, Helmut-Schmidt-Universit{\"a}t, Hamburg}, editor = {Weidner, Robert}, pages = {49 -- 50}, language = {de} } @inproceedings{HoecherlBottkeSchlegl, author = {H{\"o}cherl, Johannes and Bottke, Christian and Schlegl, Thomas}, title = {Eine redundante Steuerungsarchitektur zur Realisierung sicherer Mensch-Roboter-Kollaboration - Entwicklung gem{\"a}ß DIN EN ISO 10218, 13849 und 12100}, series = {Tagungsband AALE 2014}, booktitle = {Tagungsband AALE 2014}, publisher = {Deutscher Industrieverlag}, address = {M{\"u}nchen}, isbn = {978-3-8356-7142-3}, pages = {165 -- 173}, abstract = {Das Forschungsprojekt ManuCyte konzentriert sich auf die Realisierung einer Plattform f{\"u}r die Kultivierung menschlicher Zellen und Gewebe im industriellen Maßstab. F{\"u}r die Mensch-Roboter-Kolloboration ist die Robotersteuerung technologisch diversit{\"a}r und redundant ausgef{\"u}hrt. Skizziert und analysiert wird ein prototypisches Robotersystem zum Erhalt von sicherer Mensch-Roboter-Kollaboration. Eine normgerechte Risikobeurteilung wird anhand der vorliegenden Anwendung Schritt f{\"u}r Schritt aufgezeigt. Wichtige Kenngr{\"o}ßen zur Bestimmung des sicherheitstechnischen Leistungsgrades sicherheitsrelevanter Steuerungsfunktionen werden exemplarisch berechnet und zusammengefasst. Die Vorgehensweise der Steuerungsentwicklung und die entwickelte Steuerungsarchitektur werden aufgezeigt. Außerdem werden die Sicherheitsanforderungen exemplarisch validiert und die Ergebnisse diskutiert. Aufgezeigt werden die Entwicklungsschritte zu einer m{\"o}glichen Zertifizierung. A prototypic robot system for Human-Robot Collaboration is sketched and analyzed in the article at hand. For the present application, the risk assessment according to the relevant standards is visualized step by step. Important parameters to determine the safety performance level of safety related control functions are calculated and summarized. The procedure to develop a safe control system and the developed control architecture are shown. Furthermore, the safety requirements are validated exemplarily and the results are discussed. Possible steps to carry the system to a certification complete the present article.}, language = {de} } @inproceedings{HoecherlPohltNiedersteineretal., author = {H{\"o}cherl, Johannes and Pohlt, Clemens and Niedersteiner, Sascha and Schlegl, Thomas and Haug, Sonja and Weber, Karsten}, title = {Entwicklung eines industriellen Assistenzsystems unter Einbeziehung der Anlagenbediener}, series = {2. OTH Clusterkonferenz}, booktitle = {2. OTH Clusterkonferenz}, organization = {OTH Regensburg und OTH Amberg-Weiden}, pages = {11 -- 15}, language = {de} } @inproceedings{HaugGlashauserGrossmannetal., author = {Haug, Sonja and Glashauser, Lisa and Großmann, Benjamin and Pohlt, Clemens and Schlegl, Thomas and Wackerbarth, Alena and Weber, Karsten}, title = {Gamification im Anlernprozess am Industriearbeitsplatz}, series = {2. OTH Clusterkonferenz}, booktitle = {2. OTH Clusterkonferenz}, organization = {OTH Regensburg und OTH Amberg-Weiden}, pages = {183 -- 188}, language = {de} } @inproceedings{WeberHaugSchlegletal., author = {Weber, Karsten and Haug, Sonja and Schlegl, Thomas and Pohlt, Clemens and H{\"o}cherl, Johannes}, title = {Kollaborative Robotik als Beispiel der Mensch-Maschine-Interaktion}, series = {Tagung Technikfolgenabsch{\"a}tzung, 19.06.2017, Akademie der Wissenschaften Wien}, booktitle = {Tagung Technikfolgenabsch{\"a}tzung, 19.06.2017, Akademie der Wissenschaften Wien}, language = {de} } @inproceedings{HaugGlashauserGrossmannetal., author = {Haug, Sonja and Glashauser, Lisa and Großmann, Benjamin and Pohlt, Clemens and Schlegl, Thomas and Wackerbarth, Alena and Weber, Karsten}, title = {Gamification im Anlernprozess am Industriearbeitsplatz - ein inklusiver Ansatz}, series = {2. Transdisziplin{\"a}ren Konferenz "Technische Unterst{\"u}tzungssysteme, die die Menschen wirklich wollen", 12.-13.12.2016, Helmut- Schmidt-Universit{\"a}t Hamburg}, booktitle = {2. Transdisziplin{\"a}ren Konferenz "Technische Unterst{\"u}tzungssysteme, die die Menschen wirklich wollen", 12.-13.12.2016, Helmut- Schmidt-Universit{\"a}t Hamburg}, editor = {Weidner, Robert}, pages = {421 -- 430}, abstract = {Um die Lebensqualit{\"a}t und Einsatzf{\"a}higkeit von Menschen mit Behinderung oder {\"a}lteren Menschen zu verbessern, wurde untersucht, inwiefern Gamification-Anwendungen beim Anlernen einer Gestensteuerung geeignet sind. Grundlage des Experiments stellt ein intelligenter Arbeitsplatz (Smart Workbench, SWoB) dar, der Personen bei manuellen Handhabungsaufgaben unterst{\"u}tzt sowie bestimmte Produktionsprozesse teilautomatisiert ausf{\"u}hrt. Um die Anlage bedienen zu k{\"o}nnen, muss im Vorfeld eine Einweisung erfolgen, welche von Menschen oder durch ein Lerntutorial mit Gamification-Elementen zur Motivationssteigerung durchgef{\"u}hrt werden kann. In der Studie wurde untersucht, welche Form des Anleitens aus welchen Gr{\"u}nden von unterschiedlichen Personen eher akzeptiert oder abgelehnt wird.}, language = {de} } @inproceedings{LangBeckeSchlegl, author = {Lang, Jonas and Becke, Mark and Schlegl, Thomas}, title = {A Systematic Approach for the Parameterisation of the Kernel-Based Hough Transform Using a Human-Generated Ground Truth}, series = {Intelligent Robotics and Applications}, volume = {9244}, booktitle = {Intelligent Robotics and Applications}, editor = {Liu, Honghai and Kubota, Naoyuki and Zhu, Xiangyang and Dillmann, R{\"u}diger and Zhou, Dalin}, publisher = {Springer}, address = {Cham}, isbn = {978-3-319-22878-5}, doi = {10.1007/978-3-319-22879-2_44}, pages = {473 -- 486}, abstract = {Lines are one of the basic features that are used to characterise the content of an image and to detect objects. Unlike edges or segmented blobs, lines are not only an accumulation of certain feature pixels but can also be described in an easy and exact mathematical way. Besides a lot of different detection methods, the Hough transform has gained much attention in recent years. With increasing processing power and continuous development, computer vision algorithms get more powerful with respect to speed, robustness and accuracy. But there still arise problems when searching for the best parameters for an algorithm or when characterising and evaluating the results of feature detection tasks. It is often difficult to estimate the accuracy of an algorithm and the influences of the parameter selection. Highly interdependent parameters and preprocessing steps continually lead to only hardly comprehensible results. Therefore, instead of pure trial and error and subjective ratings, a systematic assessment with a hard, numerical evaluation criterion is suggested. The paper at hand deals with the latter ones by using a human-generated ground truth to approach the problem. Thereby, the accuracy of the surveyed Kernel-based Hough transform algorithm was improved by a factor of three. These results are used for the tracking of cylindrical markers and to reconstruct their spatial arrangement for a biomedical research application.}, language = {en} } @article{HoecherlWredeSchlegl, author = {Hoecherl, Johannes and Wrede, Britta and Schlegl, Thomas}, title = {Developing human-robot assembly cells - Simulation, virtual interaction, and applications}, series = {ATP EDITION}, journal = {ATP EDITION}, number = {5}, publisher = {DIV DEUTSCHER INDUSTRIEVERLAG GMBH}, pages = {34 -- 42}, abstract = {In human-robot assembly cells, some tasks in a production process are carried out by the user, others by the robot, and some tasks are carried out in collaboration. However, the potential and advantages of such systems have not yet been fully harnessed. A systematic approach is needed to design cooperative workflows. Here, an iterative, user-centred development cycle is presented for interactive human-robot applications, complementing traditional automation. Virtual reality development is applied to evaluate the workflows to be defined and to develop a more efficient overall design cycle.}, language = {en} } @inproceedings{HoecherlAdamSchlegletal., author = {H{\"o}cherl, Johannes and Adam, Andreas and Schlegl, Thomas and Wrede, Britta}, title = {Human-Robot Assembly: Methodical Design and Assessment of an Immersive Virtual Environment for Real-World Significance}, series = {2020 25th IEEE International Conference on Emerging Technologies and Factory Automation (ETFA): 8-11 Sept. 2020, Vienna, Austria}, booktitle = {2020 25th IEEE International Conference on Emerging Technologies and Factory Automation (ETFA): 8-11 Sept. 2020, Vienna, Austria}, publisher = {IEEE}, doi = {10.1109/ETFA46521.2020.9212039}, pages = {549 -- 556}, abstract = {Virtual reality is a powerful tool for industrial applications. The article at hand addresses designers of industrial virtual environments. It summarizes key aspects to design immersive and coherent virtual environments. Furthermore, relevant influencing factors for a high quality virtual environment and tools to quantify this quality are presented. So far, a methodology to design, evaluate, and transfer knowledge from virtual environments into reality has been missing and is of high value for industrial applications. The proposed methodical approach includes the steps application analysis, technology selection and integration, design of virtual environment, evaluation of simulator quality, as well as discussion of the real-world validity. The method is shown on the example of a virtual human-robot working cell used to analyze the human perception of robot behavior during mutual assembly processes. The quality of the virtual environment is evaluated to be adequate for those purposes and the transfer of knowledge gained in virtuality on a corresponding real-world application is discussed. To the best of our knowing a system like the presented one, including full-body tracking, finger tracking, a virtual avatar and a head-mounted display has not been used for industrial use cases and human-robot cooperation before.}, language = {en} } @inproceedings{PohltSchleglWachsmuth, author = {Pohlt, Clemens and Schlegl, Thomas and Wachsmuth, Sven}, title = {Human Work Activity Recognition for Working Cells in Industrial Production Contexts}, series = {2019 IEEE International Conference on Systems, Man and Cybernetics (SMC), 6-9 Oct. 2019, Bari, Italy}, booktitle = {2019 IEEE International Conference on Systems, Man and Cybernetics (SMC), 6-9 Oct. 2019, Bari, Italy}, doi = {10.1109/SMC.2019.8913873}, pages = {4225 -- 4230}, abstract = {Collaboration between robots and humans requires communicative skills on both sides. The robot has to understand the conscious and unconscious activities of human workers. Many state-of-the-art activity recognition algorithms with high performance rates on existing benchmark datasets are available for this task. This paper re-evaluates appropriate architectures in light of human work activity recognition for working cells in industrial production contexts. The specific constraints of such a domain is elaborated and used as prior knowledge. We utilize state-of-the-art algorithms as spatiotemporal feature encoders and search for appropriate classification and fusion strategies. Furthermore, we combine keypoint-based with appearance-based approaches to a multi-stream recognition system. Due to data protection rules and the high effort of data annotation within industrial domains only small datasets are available that reflect production aspects. Therefore, we use transfer learning approaches to reduce the dependency on data volume and variance in the target domain. The resulting recognition system achieves high performance for both singular person action and human-object interaction.}, language = {en} } @incollection{LangSchlegl, author = {Lang, Jonas and Schlegl, Thomas}, title = {Camera-Projector Calibration - Methods, Influencing Factors and Evaluation Using a Robot and Structured-Light 3D Reconstruction}, series = {Intelligent Robotics and Applications}, volume = {9835}, booktitle = {Intelligent Robotics and Applications}, editor = {Kubota, Naoyuki and Kiguchi, Kazuo and Liu, Honghai and Obo, Takenori}, publisher = {Springer}, address = {Cham}, isbn = {978-3-319-43517-6}, doi = {10.1007/978-3-319-43518-3_40}, pages = {413 -- 427}, abstract = {As camera and projector hardware gets more and more affordable and software algorithms more sophisticated, the area of application for camera-projector configurations widens its scope. Unlike for sole camera calibration, only few comparative surveys for projector calibration methods exist. Therefore, in this paper, two readily available algorithms for the calibration of those arrays are studied and methods for the evaluation of the results are proposed. Additionally, statistical evaluations under consideration of different influencing factors like the hardware arrangement, the number of input images or the calibration target characteristics on the accuracy of the calibration results are performed. Ground truth comparison data is realized through a robotic system and structured light 3D scanning.}, language = {en} } @inproceedings{HoecherlWredeSchlegl, author = {H{\"o}cherl, Johannes and Wrede, Britta and Schlegl, Thomas}, title = {Motion Analysis of Human-Human and Human-Robot Cooperation During Industrial Assembly Tasks}, series = {Proceedings of the 5th International Conference on Human Agent Interaction (HAI '17), Bielefeld Germany, 17.10.2017 -20.10.2017}, booktitle = {Proceedings of the 5th International Conference on Human Agent Interaction (HAI '17), Bielefeld Germany, 17.10.2017 -20.10.2017}, editor = {Wrede, Britta and Nagai, Yukie and Komatsu, Takanori and Hanheide, Marc and Natale, Lorenzo}, publisher = {ACM}, address = {New York, NY, USA}, isbn = {9781450351133}, doi = {10.1145/3125739.3132615}, pages = {425 -- 429}, abstract = {This article discusses the relevance of the motion behavior and adaptation of a collaborative robot for human-robot cooperation. Two experiments on cooperative assembly are shown. First, a human-human experiment with defined test conditions evaluates the aspects of distance, nearest body part, and predictability as significant. Second, a human-robot experiment shows that fixed trajectories and conservative dynamic parameters lead to a quick gain of confidence of the participants. Besides, the data shows that a realistic use case with complex tasks is key to evaluate the impact of motion parameters.}, language = {en} } @article{HoecherlWredeSchlegl, author = {H{\"o}cherl, Johannes and Wrede, Britta and Schlegl, Thomas}, title = {Mensch-Roboter-Arbeitsabl{\"a}ufe methodisch entwickeln}, series = {atp edition (Automatisierungstechnische Praxis)}, volume = {59}, journal = {atp edition (Automatisierungstechnische Praxis)}, number = {5}, publisher = {DIV Dt. Industrieverlag}, address = {M{\"u}nchen}, issn = {2190-4111}, pages = {34 -- 42}, abstract = {In Mensch-Roboter-Arbeitszellen werden Teile eines Produktionsablaufs von einemv Menschen, andere von einem kollaborativen Roboter und wieder andere kooperativvin einem gemeinsamen Arbeitsbereich durchgef{\"u}hrt. Bisher werden das Potenzialvund der Mehrwert dieser Systeme noch nicht ausgesch{\"o}pft, weshalb ein systematischer Ansatz zur Definition der Arbeitsabl{\"a}ufe unerl{\"a}sslich ist. Der Beitrag pr{\"a}sentiert einen iterativen, menschzentrierten Entwicklungszyklus f{\"u}r interaktive Mensch-Roboter-Anwendungen. Dieser Zyklus erg{\"a}nzt die bisher verwendeten Ans{\"a}tze der Automatisierung. Er beinhaltet Methoden der virtuellen Realit{\"a}t, um die Arbeitsabl{\"a}ufe iterativ evaluieren und dadurch den Entwicklungsprozess effizient gestalten zu k{\"o}nnen.}, language = {de} } @article{GrossmannSchlegl, author = {Grossmann, Benjamin and Schlegl, Thomas}, title = {Telerobotiksysteme zum industriellen Einsatz. Entwicklung einer vierkanaligen Regelungsarchitektur : Telerobotic systems for industrial applications. Development of a four-channel control architecture}, series = {atp edition. Automatisierungstechnische Praxis}, volume = {57}, journal = {atp edition. Automatisierungstechnische Praxis}, number = {6}, publisher = {DIV Deutscher Industrieverlag}, pages = {48 -- 55}, abstract = {Die Regensburg Robotics Research Unit entwickelt Regelungsarchitekturen f{\"u}r Telerobotiksysteme f{\"u}r den industriellen Einsatz. Der Beitrag beschreibt das lokale und globale Regelungsmodell hinsichtlich Stabilit{\"a}t und Transparenz auf der Basis der von Lawrence und Yokokohji vorgestellten Regelungsarchitektur und zeigt Simulationsergebnisse auf. Die Modellbildung des geregelten Manipulators, die Kopplung des Operators und des Teleoperators und sowie die {\"U}bertragungsfunktion werden dargestellt. Die Simulation des vorgestellten Algorithmus in Matlab/Simulink wird durchgef{\"u}hrt. Innerhalb der Simulationsumgebung ist als Regelstrecke unter der Annahme einer idealen, lokalen Regelung eine im Raum bewegliche Punktmasse modelliert. Die vorgestellte Regelungsarchitektur liefert innerhalb der durchgef{\"u}hrten Simulation vor allem im niederfrequenten Bereich sehr gute Ergebnisse. Die n{\"a}chsten Schritte sind die experimentelle Evaluierung der lokalen Architektur und der globalen Vierkanalarchitektur an den Robotern.}, language = {de} } @article{HoecherlBottkeSchlegl, author = {H{\"o}cherl, Johannes and Bottke, Christian and Schlegl, Thomas}, title = {Steuerungsarchitektur f{\"u}r kollaborierende Roboter. Analyse - Risikobeurteilung - Entwurf - Validierung}, series = {atp edition. Automatisierungstechnische Praxis}, volume = {57}, journal = {atp edition. Automatisierungstechnische Praxis}, number = {6}, publisher = {DIV Deutscher Industrieverlag}, address = {Essen}, doi = {10.17560/atp.v57i06.497}, pages = {38 -- 46}, abstract = {Der Beitrag beschreibt den Systemaufbau f{\"u}r die Risikobeurteilung zur Realisierung einer sicheren Mensch-Maschine-Kollaboration und stellt die vorgeschriebene Risikobeurteilung gem{\"a}ß DIN EN ISO 10218-1:2012-01 in folgende Schritten vor: Beurteilung der Erfahrenswerte und des Nutzerverhaltens, Festlegung der Grenzen des Roboters, Identifikation der Gef{\"a}hrdungen und Risikoeinsch{\"a}tzung in den dimensionen Ausmaß, Exposition, Eintrittswahrscheinlichkeit und Vermeidungsm{\"o}glichkeit. Die Umsetzung in eine Steuerung, die Steuerungsarchitektur und die eingesetzten Komponenten zur Realisierung einer sicheren Abstands{\"u}berwachung werden beschrieben und in Blockschaltbildern grafisch dargestellt. Die Validit{\"a}t der Sicherheitsfunktion wird diskutiert.}, language = {de} } @inproceedings{HoecherlSchmargendorfWredeetal., author = {Hoecherl, Johannes and Schmargendorf, Maike and Wrede, Britta and Schlegl, Thomas}, title = {User-Centered Design of Multimodal Robot Feedback for Cobots of Human-RobotWorking Cells in Industrial Production Contexts}, series = {50th International Symposium on Robotics (ISR 2018) : Munich, Germany, 20-21 June 2018}, booktitle = {50th International Symposium on Robotics (ISR 2018) : Munich, Germany, 20-21 June 2018}, publisher = {Curran Associates, Inc.}, address = {Red Hook, NY}, isbn = {978-3-8007-4699-6}, pages = {1 -- 8}, abstract = {This article discusses the systematic design of the robot feedback for users in a stationary human-robot cooperation scenario. The design cycle starts with the analysis of related work and the capabilities of the human-robot system. It is followed by an online questionnaire with 100 participants to discover relevant information and modalities. A final experiment in the human-robot working cell with 13 subjects evaluates the usability of the robot feedback design.}, language = {en} } @inproceedings{MilaevRuiderSchlegl, author = {Milaev, Johannes and Ruider, Martin and Schlegl, Thomas}, title = {Entwicklung eines Experimentalsystems zur Validierung adaptiver Regelungen mit einem OEM-Steuerger{\"a}t}, series = {Tagungsband AALE 2014 : das Forum f{\"u}r Fachleute der Automatisierungstechnik aus Hochschulen und Wirtschaft ; 11. Fachkonferenz, Regensburg}, booktitle = {Tagungsband AALE 2014 : das Forum f{\"u}r Fachleute der Automatisierungstechnik aus Hochschulen und Wirtschaft ; 11. Fachkonferenz, Regensburg}, publisher = {Deutscher Industrieverlag}, address = {M{\"u}nchen}, isbn = {978-3-8356-7142-3}, pages = {241 -- 250}, abstract = {Im Rahmen des Kooperationsprojektes "ACES" (Integrated Adaption of Linear Controllers for Embedded Systems) ist ein Pr{\"u}fstand zur Validierung adaptiver Regelungen entwickelt und aufgebaut worden, der das dynamische Verhalten eines Kfz-Antriebstrangs aufweist. Ziel ist es, verschiedene Adaptionsverfahren auf ihre Einsetzbarkeit in OEM-Steuerger{\"a}ten, die im Automotive-Bereich auf breiter Basis verwendet werden, kosteng{\"u}nstig testen zu k{\"o}nnen. Das Problem der aktiven Schwingungsd{\"a}mpfung in Kfz-Antriebsstr{\"a}ngen mit unbekannten und ver{\"a}nderlichen mechanischen Parametern stellt eine Pilotanwendung dar. Ein leicht anpassbarer mechanischer Pr{\"u}fstand dient hierbei als vereinfachtes Modell eines Antriebstrangs. Dieser ist Bestandteil eitles Experimentalsystems mit einer informationstechnischen Architektur, die einen Betrieb engebetteter Regelungssysteme auf verschiedenen Plattformen gestattet. Das flexible mechanische und informationstechnische Design des Experimentalsystems gestattet die Variation von Parametern der zu regelnden Applikation durch leicht austauschbare mechanische Komponenten und gezielte Einbringung von St{\"o}rgr{\"o}ßen. Zudem kann die Berechnung der Regelungsarchitektur auf einem Industrie-PC oder einem Steuerger{\"a}t erfolgen. Weitere Vorteile des entwickelten Experimentalsystems sind die Ber{\"u}cksichtigung von Effekten, die aus dem Verhalten realer Sensoren und der CAN-basierten Signal{\"u}bertragung entstehen. Insbesondere der Einfluss von Wortbreite und Latenz {\"u}bertragener Signale auf die Adaption von Regelungen kann mit Hilfe des vorgestellten Experimentalsystems eingehend untersucht werden.}, language = {de} } @inproceedings{GrossmannSchlegl, author = {Großmann, Benjamin and Schlegl, Thomas}, title = {Entwicklung einer Regelungsarchitektur f{\"u}r ein Telepr{\"a}senzsystem}, series = {Tagungsband AALE 2014}, booktitle = {Tagungsband AALE 2014}, publisher = {Deutscher Industrieverlag}, address = {M{\"u}nchen}, isbn = {978-3-8356-7142-3}, pages = {285 -- 294}, abstract = {Es wird dargelegt, wie das Verhalten eines Manipulators durch die Vorsteuerung von Drehmomenten und die Anwendung von kinematischen Beziehungen zu einer Punktmasse vereinfacht werden kann. Der darauf aufbauende, vorgestellte Algorithmus zur Kopplung des Operators mit dem Teleoperator ist mathematisch beschrieben und hinsichtlich der Problematik von Differentiationen in der realen Anwendung angepasst. Die vorgestellte Simulation mit zwei Testsignalen sowie die Frequenzganganalyse eines Koppelterms zeigen, dass der Algorithmus vor allem bei niedrigen Frequenzen dem Bediener ein hohes Maß an Transparenz liefert. Eine Frequenzganganalyse bei Variation der parametrierbaren {\"U}bertragungsfunktionen kann die Transparenz bei hohen Frequenzen verbessern. N{\"a}chste Schritte konzentrieren sich auf die experimentelle Evaluierung einer vorgestellten Kraftregelungsarchitektur am Assistenzroboter CARo5X. Insbesondere wird gepr{\"u}ft, ob die Annahme eines linearisierten und entkoppelten Systems am Experimentalaufbau hinreichend zutrifft. Nach erfolgter Inbetriebnahme der vorgestellten Kraftregelung am Robotersystem SixAx, das von der Regensburg Robotics Research Unit (RRRU) entwickelt worden ist, werden beide Roboter durch den vorgestellten Ansatz gekoppelt und final experimentell bewertet.}, language = {de} } @inproceedings{BeckeSchlegl, author = {Becke, Mark and Schlegl, Thomas}, title = {Least squares pose estimation of cylinder axes from multiple views using contour line features}, series = {IECON 2015 - 41st Annual Conference of the IEEE Industrial Electronics Society, 9-12 Nov. 2015, Yokohama, Japan}, booktitle = {IECON 2015 - 41st Annual Conference of the IEEE Industrial Electronics Society, 9-12 Nov. 2015, Yokohama, Japan}, publisher = {IEEE}, doi = {10.1109/IECON.2015.7392371}, pages = {1855 -- 1861}, abstract = {In this paper, a new method for a minimum-error pose estimation of cylinder axes based on apparent contour line features from multiple views is presented. Novel model equations for both single and particularly multiple views are derived, and based upon these, an iterative algorithm for least squares fitting the model to imaged cylinder contour line features is introduced. The good performance and fast convergence of the proposed algorithm is shown by solving exemplary fitting problems.}, language = {en} } @inproceedings{BauerGrossmannSchlegletal., author = {Bauer, Gregor and Grossmann, Benjamin and Schlegl, Thomas and Kobayashi, Hiroshi}, title = {Modeling, identification and control of an antagonistically actuated joint for telerobotic systems}, series = {IECON 2015 - 41st Annual Conference of the IEEE Industrial Electronics Society, 9-12 Nov. 2015, Yokohama, Japan}, booktitle = {IECON 2015 - 41st Annual Conference of the IEEE Industrial Electronics Society, 9-12 Nov. 2015, Yokohama, Japan}, publisher = {IEEE}, doi = {10.1109/IECON.2015.7392676}, pages = {3696 -- 3701}, abstract = {Within this paper a modeling, identification and control technique for an antagonistically actuated joint consisting of two pneumatically actuated muscles is presented. The antagonistically actuated joint acts as a test bench for control architectures which are going to be used to control an exoskeleton within a telerobotic system. A static and dynamic model of the muscle and the joint is derived and the parameters of the models are identified using a least-squares algorithm. The control architecture, consisting of a inner pressure and an outer position controller is presented. The pressure controller is evaluated using switching valves compared against proportional valves.}, language = {en} } @inproceedings{PohltHaubnerLangetal., author = {Pohlt, Clemens and Haubner, Franz and Lang, Jonas and Rochholz, Sandra and Schlegl, Thomas and Wachsmuth, Sven}, title = {Effects on User Experience During Human-Robot Collaboration in Industrial Scenarios}, series = {2018 IEEE International Conference on Systems, Man, and Cybernetics (SMC), 7-10 Oct. 2018, Miyazaki, Japan}, booktitle = {2018 IEEE International Conference on Systems, Man, and Cybernetics (SMC), 7-10 Oct. 2018, Miyazaki, Japan}, publisher = {IEEE}, doi = {10.1109/SMC.2018.00150}, pages = {837 -- 842}, abstract = {In smart manufacturing environments robots collaborate with human operators as peers. They even share the same working space and time. An intuitive interaction with different input modalities is decisive to reduce workload and training periods for collaboration. We introduce our interaction system that is able to recognize gestures, actions and objects in a typical smart working scenario. As key aspect, this article considers an empirical investigation of input modalities (touch, gesture), individual differences (performance, recognition rate, previous knowledge) and boundary conditions (level of automation) on user experience. Therefore, answers from 31 participants within two experiments are collected. We show that the arrangement of the human-robot collaboration (input modalities, boundary conditions) has a significant effect on user experience in real-world environments. This effect and the individual differences between participants can be measured utilizing recognition rates and standardized usability questionnaires.}, language = {en} } @inproceedings{WeissGrossmannLeiboldetal., author = {Weiß, Roman and Großmann, Benjamin and Leibold, Marion and Schlegl, Thomas and Wollherr, Dirk and Weiss, Roman and Grossmann, Benjamin}, title = {Modeling and nonlinear control of antagonistically actuating pneumatic artificial muscles}, series = {2017 IEEE International Conference on Advanced Intelligent Mechatronics (AIM), 3-7 July 2017, Munich, Germany}, booktitle = {2017 IEEE International Conference on Advanced Intelligent Mechatronics (AIM), 3-7 July 2017, Munich, Germany}, publisher = {IEEE}, doi = {10.1109/AIM.2017.8014001}, pages = {94 -- 99}, abstract = {This paper discusses modeling and nonlinear control of a joint antagonistically actuated by two pneumatic, artificial muscles. A single model of the whole system is obtained by a combined physical and phenomenological modeling approach. The combined model for the joint, the muscles and the proportional valves results in a nonlinear, affine-in-control system description. The model is used to derive control laws for an input/output linearization approach to linearize the plant. Modeling and parametrization errors are covered via an outer control loop consisting of a state-feedback which is extended by an additional feedback of error integral. Extensive experimental results show the quality of the model and the performance of the respective control laws.}, language = {en} } @inproceedings{PohltHellSchlegletal., author = {Pohlt, Clemens and Hell, Sebastian and Schlegl, Thomas and Wachsmuth, Sven}, title = {Impact of Spontaneous Human Inputs during Gesture based Interaction on a Real-World Manufacturing Scenario}, series = {Proceedings of the 5th International Conference on Human Agent Interaction (HAI '17), Bielefeld Germany, 17.10.2017 -20.10.2017}, booktitle = {Proceedings of the 5th International Conference on Human Agent Interaction (HAI '17), Bielefeld Germany, 17.10.2017 -20.10.2017}, editor = {Wrede, Britta and Nagai, Yukie and Komatsu, Takanori and Hanheide, Marc and Natale, Lorenzo}, publisher = {ACM}, address = {New York, NY}, isbn = {9781450351133}, doi = {10.1145/3125739.3132590}, pages = {347 -- 351}, abstract = {Seamless human-robot collaboration depends on high non-verbal behaviour recognition rates. To realize that in real-world manufacturing scenarios with an ecological valid setup, a lot of effort has to be invested. In this paper, we evaluate the impact of spontaneous inputs on the robustness of human-robot collaboration during gesture-based interaction. A high share of these spontaneous inputs lead to a reduced capability to predict behaviour and subsequently to a loss of robustness. We observe body and hand behaviour during interactive manufacturing of a collaborative task within two experiments. First, we analyse the occurrence frequency, reason and manner of human inputs in specific situations during a human-human experiment. We show the high impact of spontaneous inputs, especially in situations that differ from the typical working procedure. Second, we concentrate on implicit inputs during a real-world Wizard of Oz experiment using our human-robot working cell. We show that hand positions can be used to anticipate user needs in a semi-structured environment by applying knowledge about the semi-structured human behaviour which is distributed over working space and time in a typical manner.}, language = {en} } @inproceedings{PohltSchleglWachsmuth, author = {Pohlt, Clemens and Schlegl, Thomas and Wachsmuth, Sven}, title = {Weakly-Supervised Learning for Multimodal Human Activity Recognition in Human-Robot Collaboration Scenarios}, series = {2020 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS): October 25-29, 2020, Las Vegas, NV, USA (virtual)}, booktitle = {2020 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS): October 25-29, 2020, Las Vegas, NV, USA (virtual)}, publisher = {IEEE}, doi = {10.1109/IROS45743.2020.9340788}, pages = {8381 -- 8386}, abstract = {The ability to synchronize expectations among human-robot teams and understand discrepancies between expectations and reality is essential for human-robot collaboration scenarios. To ensure this, human activities and intentions must be interpreted quickly and reliably by the robot using various modalities. In this paper we propose a multimodal recognition system designed to detect physical interactions as well as nonverbal gestures. Existing approaches feature high post-transfer recognition rates which, however, can only be achieved based on well-prepared and large datasets. Unfortunately, the acquisition and preparation of domain-specific samples especially in industrial context is time consuming and expensive. To reduce this effort we introduce a weakly-supervised classification approach. Therefore, we learn a latent representation of the human activities with a variational autoencoder network. Additional modalities and unlabeled samples are incorporated by a scalable product-of-expert sampling approach. The applicability in industrial context is evaluated by two domain-specific collaborative robot datasets. Our results demonstrate, that we can keep the number of labeled samples constant while increasing the network performance by providing additional unprocessed information.}, language = {en} } @article{NiedersteinerLangPohltetal., author = {Niedersteiner, Sascha and Lang, Jonas and Pohlt, Clemens and Schlegl, Thomas}, title = {Klassifikation des Arbeitsfortschritts}, series = {atp magazin}, volume = {59}, journal = {atp magazin}, number = {11}, publisher = {Vulkan-Verlag}, doi = {10.17560/atp.v59i11.1911}, pages = {58 -- 66}, abstract = {Steigende Anforderungen an die Qualit{\"a}t von zum Teil manuell gefertigten Produkten f{\"u}hren dazu, dass Handarbeitspl{\"a}tze mit Assistenzsystemen f{\"u}r die Unterst{\"u}tzung der am Arbeitsplatz arbeitenden Mitarbeiterinnen und Mitarbeiter ausgestattet werden. Der Beitrag beschreibt einen neuen Ansatz, um mittels Verfahren des maschinellen Lernens die Objekterkennung sowie die Transitionen eines, den Arbeitsprozess repr{\"a}sentierenden Zustandsautomaten eines solchen Systems einzulernen. Hierf{\"u}r werden nach einer Vorverarbeitung Daten aus einer Tiefenkamera in drei Stufen durch Support Vector Machines (SVM) klassifiziert und das Ergebnis mit dem Zustandsautomaten verkn{\"u}pft. Das Konzept wird an einem industriellen Montageprozess {\"u}berschaubarer Komplexit{\"a}t evaluiert; es zeigt gute Ergebnisse hinsichtlich der Robustheit gegen{\"u}ber Fehlern bei der Objektklassifikation.}, language = {de} } @article{NiedersteinerLangPohltetal., author = {Niedersteiner, Sascha and Lang, Jonas and Pohlt, Clemens and Schlegl, Thomas}, title = {Tracking work task completion - A support vector machine approach for assisting workbenches}, series = {atp edition}, journal = {atp edition}, number = {11}, publisher = {DIV Deutscher Industrieverl.}, doi = {10.17560/atp.v59i11.1911}, pages = {58 -- 66}, abstract = {Tightening quality requirements of industrial products involving manual assembly lead to the development of assisting workbenches with integrated functions to support workers performing these manual tasks. This contribution discusses a new approach to learning transitions of a finite state automaton representing the sequence of work tasks based on the video stream of a 3D depth camera. Preprocessed video data is fed into a three-stage classification scheme based on support vector machines. The results of the classification are then related to the state automation to trigger state transitions indicating the completion of a specific work task and the start of the next one. The proposed approach has been evaluated at an industrial assembly process of moderate complexity and shows very robust results with respect to disturbances caused by inaccurate object classification.}, language = {en} } @inproceedings{NiedersteinerPohltSchlegl, author = {Niedersteiner, Sascha and Pohlt, Clemens and Schlegl, Thomas}, title = {Smart Workbench: A Multimodal and Bidirectional Assistance System for Industrial Application}, series = {IECON 2015 - 41st Annual Conference of the IEEE Industrial Electronics Society, 09.-12.11.2015, Yokohama, Japan}, booktitle = {IECON 2015 - 41st Annual Conference of the IEEE Industrial Electronics Society, 09.-12.11.2015, Yokohama, Japan}, publisher = {IEEE}, address = {Piscataway, N.J.}, isbn = {978-1-4799-1762-4}, doi = {10.1109/iecon.2015.7392549}, abstract = {Manual tasks in industrial production are often monotonous, leading to a decrease in concentration and motivation of the worker and thus to deficiencies in the products. With quality as well as performance requirements getting more and more stringent, workers need additional support by their work environment. We developed a novel approach providing worker assistance and inline quality assurance for manual workplaces. The prototypical system Smart Workbench (SWoB) uses a multimodal sensor interface consisting of a 3D depth sensor in combination with a 2D camera to control quality aspects of the product and track the work progress. The bidirectional flow of information is handled via an image processing driven gestural interface and the displaying of advice directly on the work surface. In this paper the developed system is introduced and the current state of evaluating its industrial usage with a manual quality control and packaging task reported.}, language = {en} } @article{GrossmannSchlegl, author = {Großmann, Benjamin and Schlegl, Thomas}, title = {Development of a Hybrid Path/Force Control Architecture for an Assisting Robot}, series = {International journal of mechanics and control : JoMaC}, volume = {15}, journal = {International journal of mechanics and control : JoMaC}, number = {1}, publisher = {Levrotto\&Bella}, address = {Torino}, issn = {1590-8844}, pages = {27 -- 34}, abstract = {For human machine interaction a control ar chitecture for the force controlled guidance mode of a five axis robot is developed. This enables a human operator to move the robot easily by applying forces at th e end-effector. The position and th e path can then be tracked and stored for a later reuse. The control archit ecture is also used in a hybrid mode where it is possible to control chosen workspace coordinates with a path controller and others with a force controller. The hybrid mode is especially used to cut tissue material with a scalpel which is mounted at the robots effector.}, language = {en} } @article{SchleglRobatzekKuceraetal., author = {Schlegl, Peter and Robatzek, Patrick and Kucera, Markus and Volbert, Klaus and Waas, Thomas}, title = {Performance analysis of mobile radio for automatic control in smart grids}, series = {International Journal of Advancements in Electronics and Electrical Engineering}, volume = {4}, journal = {International Journal of Advancements in Electronics and Electrical Engineering}, number = {1}, issn = {2319-7498}, pages = {69 -- 75}, abstract = {In the context of a "Smart Grid" research project, together with industrial partners, the OTH-Regensburg realized an intelligent medium-voltage grid in the local area. Goal was to improve the current voltage regulation and to counter the problems with inconsistent energy feed-in of decentralized renewable energy producers. In this paper we discuss the possibilities of using 3rd generation (3G) cellular networks (UMTS) as basic technology to communicate the voltage-levels within a medium-voltage grid. We build an experimental hardware setup to generate data-traffic as specified for the smart grid. By analyzing the performance of 3G cellular networks in terms of transmission latency and rate of failure, we tried to evaluate the usability of this technology for such critical data exchange. Though mobile communication in its structure is not specified for the use of transmitting such infrastructure critical data, the results show a promising high reliability with low transmission latency. The experiments served just to test a fragment of the conditions of use in a real scenario. An expanded test scope is needed to further analyze the performance of mobile radio for automatic control in smart grids. In the end the results discussed in this paper led to a successful prototype of an intelligent medium-voltage grid with mobile radio as communication technology}, language = {en} } @article{BrollRosentrittSchlegletal., author = {Broll, Alexander and Rosentritt, Martin and Schlegl, Thomas and Goldhacker, Markus}, title = {A data-driven approach for the partial reconstruction of individual human molar teeth using generative deep learning}, series = {Frontiers in Artificial Intelligence}, volume = {7}, journal = {Frontiers in Artificial Intelligence}, publisher = {Frontiers Media SA}, issn = {2624-8212}, doi = {10.3389/frai.2024.1339193}, abstract = {Background and objectiveDue to the high prevalence of dental caries, fixed dental restorations are regularly required to restore compromised teeth or replace missing teeth while retaining function and aesthetic appearance. The fabrication of dental restorations, however, remains challenging due to the complexity of the human masticatory system as well as the unique morphology of each individual dentition. Adaptation and reworking are frequently required during the insertion of fixed dental prostheses (FDPs), which increase cost and treatment time. This article proposes a data-driven approach for the partial reconstruction of occlusal surfaces based on a data set that comprises 92 3D mesh files of full dental crown restorations.MethodsA Generative Adversarial Network (GAN) is considered for the given task in view of its ability to represent extensive data sets in an unsupervised manner with a wide variety of applications. Having demonstrated good capabilities in terms of image quality and training stability, StyleGAN-2 has been chosen as the main network for generating the occlusal surfaces. A 2D projection method is proposed in order to generate 2D representations of the provided 3D tooth data set for integration with the StyleGAN architecture. The reconstruction capabilities of the trained network are demonstrated by means of 4 common inlay types using a Bayesian Image Reconstruction method. This involves pre-processing the data in order to extract the necessary information of the tooth preparations required for the used method as well as the modification of the initial reconstruction loss.ResultsThe reconstruction process yields satisfactory visual and quantitative results for all preparations with a root mean square error (RMSE) ranging from 0.02 mm to 0.18 mm. When compared against a clinical procedure for CAD inlay fabrication, the group of dentists preferred the GAN-based restorations for 3 of the total 4 inlay geometries.ConclusionsThis article shows the effectiveness of the StyleGAN architecture with a downstream optimization process for the reconstruction of 4 different inlay geometries. The independence of the reconstruction process and the initial training of the GAN enables the application of the method for arbitrary inlay geometries without time-consuming retraining of the GAN.}, language = {en} }