{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,11,4]],"date-time":"2025-11-04T23:52:00Z","timestamp":1762300320120,"version":"build-2065373602"},"reference-count":43,"publisher":"MDPI AG","issue":"6","license":[{"start":{"date-parts":[[2023,3,15]],"date-time":"2023-03-15T00:00:00Z","timestamp":1678838400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100001871","name":"FCT\/MCTES (PIDDAC) to CeDRI","doi-asserted-by":"publisher","award":["UIDB\/05757\/2020","UIDP\/05757\/2020","LCF\/BQ\/DI20\/11780028"],"award-info":[{"award-number":["UIDB\/05757\/2020","UIDP\/05757\/2020","LCF\/BQ\/DI20\/11780028"]}],"id":[{"id":"10.13039\/501100001871","id-type":"DOI","asserted-by":"publisher"}]},{"name":"La Caixa","award":["UIDB\/05757\/2020","UIDP\/05757\/2020","LCF\/BQ\/DI20\/11780028"],"award-info":[{"award-number":["UIDB\/05757\/2020","UIDP\/05757\/2020","LCF\/BQ\/DI20\/11780028"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>Localization is a crucial skill in mobile robotics because the robot needs to make reasonable navigation decisions to complete its mission. Many approaches exist to implement localization, but artificial intelligence can be an interesting alternative to traditional localization techniques based on model calculations. This work proposes a machine learning approach to solve the localization problem in the RobotAtFactory 4.0 competition. The idea is to obtain the relative pose of an onboard camera with respect to fiducial markers (ArUcos) and then estimate the robot pose with machine learning. The approaches were validated in a simulation. Several algorithms were tested, and the best results were obtained by using Random Forest Regressor, with an error on the millimeter scale. The proposed solution presents results as high as the analytical approach for solving the localization problem in the RobotAtFactory 4.0 scenario, with the advantage of not requiring explicit knowledge of the exact positions of the fiducial markers, as in the analytical approach.<\/jats:p>","DOI":"10.3390\/s23063128","type":"journal-article","created":{"date-parts":[[2023,3,15]],"date-time":"2023-03-15T05:22:59Z","timestamp":1678857779000},"page":"3128","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":12,"title":["A Machine Learning Approach to Robot Localization Using Fiducial Markers in RobotAtFactory 4.0 Competition"],"prefix":"10.3390","volume":"23","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-6306-574X","authenticated-orcid":false,"given":"Luan C.","family":"Klein","sequence":"first","affiliation":[{"name":"Department of Electronics (DAELN), Universidade Tecnol\u00f3gica Federal do Paran\u00e1 (UTFPR), Curitiba 80230-901, Brazil"},{"name":"Research Center in Digitalization and Intelligent Robotics (CeDRI), Instituto Polit\u00e9cnico de Bragan\u00e7a, 5300-253 Bragan\u00e7a, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0276-4314","authenticated-orcid":false,"given":"Jo\u00e3o","family":"Braun","sequence":"additional","affiliation":[{"name":"Research Center in Digitalization and Intelligent Robotics (CeDRI), Instituto Polit\u00e9cnico de Bragan\u00e7a, 5300-253 Bragan\u00e7a, Portugal"},{"name":"Laborat\u00f3rio para a Sustentabilidade e Tecnologia em Regi\u00f5es de Montanha (SusTEC), Instituto Polit\u00e9cnico de Bragan\u00e7a, 5300-253 Bragan\u00e7a, Portugal"},{"name":"Faculty of Engineering, University of Porto (FEUP), Rua Dr. Roberto Frias, 4200-465 Porto, Portugal"},{"name":"INESC Technology and Science, 4200-465 Porto, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0979-8314","authenticated-orcid":false,"given":"Jo\u00e3o","family":"Mendes","sequence":"additional","affiliation":[{"name":"Research Center in Digitalization and Intelligent Robotics (CeDRI), Instituto Polit\u00e9cnico de Bragan\u00e7a, 5300-253 Bragan\u00e7a, Portugal"},{"name":"Laborat\u00f3rio para a Sustentabilidade e Tecnologia em Regi\u00f5es de Montanha (SusTEC), Instituto Polit\u00e9cnico de Bragan\u00e7a, 5300-253 Bragan\u00e7a, Portugal"},{"name":"ALGORITMI Center, University of Minho, 4710-057 Braga, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7840-0333","authenticated-orcid":false,"given":"V\u00edtor H.","family":"Pinto","sequence":"additional","affiliation":[{"name":"Faculty of Engineering, University of Porto (FEUP), Rua Dr. Roberto Frias, 4200-465 Porto, Portugal"},{"name":"SYSTEC (DIGI2)\u2014Research Center for Systems and Technologies (Digital and Intelligent Industry Lab), 4200-465 Porto, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-1032-6162","authenticated-orcid":false,"given":"Felipe N.","family":"Martins","sequence":"additional","affiliation":[{"name":"Sensors and Smart Systems Group, Institute of Engineering, Hanze University of Applied Sciences, 9747 AS Groningen, The Netherlands"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8295-366X","authenticated-orcid":false,"given":"Andre Schneider","family":"de Oliveira","sequence":"additional","affiliation":[{"name":"Department of Electronics (DAELN), Universidade Tecnol\u00f3gica Federal do Paran\u00e1 (UTFPR), Curitiba 80230-901, Brazil"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2263-0495","authenticated-orcid":false,"given":"Heinrich","family":"W\u00f6rtche","sequence":"additional","affiliation":[{"name":"Sensors and Smart Systems Group, Institute of Engineering, Hanze University of Applied Sciences, 9747 AS Groningen, The Netherlands"},{"name":"Department of Electrical Engineering, Eindhoven University of Technology, 5600 MB Eindhoven, The Netherlands"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4846-271X","authenticated-orcid":false,"given":"Paulo","family":"Costa","sequence":"additional","affiliation":[{"name":"Faculty of Engineering, University of Porto (FEUP), Rua Dr. Roberto Frias, 4200-465 Porto, Portugal"},{"name":"INESC Technology and Science, 4200-465 Porto, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-7902-1207","authenticated-orcid":false,"given":"Jos\u00e9","family":"Lima","sequence":"additional","affiliation":[{"name":"Research Center in Digitalization and Intelligent Robotics (CeDRI), Instituto Polit\u00e9cnico de Bragan\u00e7a, 5300-253 Bragan\u00e7a, Portugal"},{"name":"Laborat\u00f3rio para a Sustentabilidade e Tecnologia em Regi\u00f5es de Montanha (SusTEC), Instituto Polit\u00e9cnico de Bragan\u00e7a, 5300-253 Bragan\u00e7a, Portugal"},{"name":"INESC Technology and Science, 4200-465 Porto, Portugal"}]}],"member":"1968","published-online":{"date-parts":[[2023,3,15]]},"reference":[{"key":"ref_1","unstructured":"Huang, S., and Dissanayake, G. 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