A Fiducial-Marker-Based Localization Method for Automotive Chassis Bolt Assembly

A Fiducial-Marker-Based Localization Method for Automotive Chassis Bolt Assembly | 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 Article A Fiducial-Marker-Based Localization Method for Automotive Chassis Bolt Assembly Xiangqian Peng, Yingjie Xiao, Zhewu Chen, Kaijie Shen, Hong Huang This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-7091758/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract To address the difficulty of accurately localizing automotive chassis bolts during the assembly process—caused by non-uniform illumination, limited camera installation space, and occlusions from the vehicle body structure—a fiducial-marker-based localization method is proposed. In this method, a concentric ring-shaped fiducial marker is affixed to the bottom of the assembly wrench, and its region of interest (ROI) is extracted using an HSV color space segmentation algorithm. To overcome interference from uneven lighting and insufficient brightness in industrial environments, an improved Retinex-based image enhancement algorithm is introduced, which significantly improves the robustness and accuracy of ROI extraction. The extracted ROI image is subjected to ellipse fitting, and the fitting process is optimized by incorporating the Leitz criterion. Experimental results show that the optimized ellipse fitting algorithm achieves higher accuracy and significantly enhances the reliability of fitting. Since perspective projection of spatial circles leads to displacement of the circle center, the actual projected center of the fiducial marker in the image is calculated by estimating the normal vector of the circular plane using vanishing lines and the ellipse parameter matrix. This enables spatial localization of the bolt end. The proposed method is validated by comparing the localization results with the theoretical coordinates of the bolt holes. Experimental results demonstrate that the method offers high localization accuracy and strong robustness, meeting the practical precision requirements for automatic bolt assembly in industrial applications. Physical sciences/Engineering Physical sciences/Mathematics and computing Automotive chassis bolt assembly Visual localization method Retinex model Ellipse fitting Leitz criterion Full Text Additional Declarations No competing interests reported. Cite Share Download PDF Status: Posted Version 1 posted 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-7091758","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Article","associatedPublications":[],"authors":[{"id":498064862,"identity":"b117ba12-8aa7-49c9-a672-aa357141e161","order_by":0,"name":"Xiangqian Peng","email":"","orcid":"","institution":"Hunan University of Science and Technology","correspondingAuthor":false,"prefix":"","firstName":"Xiangqian","middleName":"","lastName":"Peng","suffix":""},{"id":498064863,"identity":"12c304ce-c671-4676-9ed8-cc189162ded9","order_by":1,"name":"Yingjie Xiao","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA2klEQVRIiWNgGAWjYBACefbmgw8kDGzk+OUPHyBOi2HPsWQDi4I0Y8kZbAlEWnMjx0yi4sPhxA03eAyI08HYkGAgccPgcGLD7Z6PN94w2MnpNhDQws5wIMFwhkG6ceOcs5st5zAkG5sdIGRLY8OBZAkDa9lmhtxt0jwMBxK3EdLCcJix4fAfA2bGNoacZ0RqOcbM2CBh4KzYI5HDRpwWwx42ZgYJgzRjCZ5jxpZzDIjwi7z8++8/JP7YyNkfb354402FnRxBLShAgtioQdZCqo5RMApGwSgYEQAAw0pEryBFEqwAAAAASUVORK5CYII=","orcid":"","institution":"Hunan University of Science and Technology","correspondingAuthor":true,"prefix":"","firstName":"Yingjie","middleName":"","lastName":"Xiao","suffix":""},{"id":498064864,"identity":"233bea16-9c18-43e9-8565-710f4a02a1c5","order_by":2,"name":"Zhewu Chen","email":"","orcid":"","institution":"Hunan University of Science and Technology","correspondingAuthor":false,"prefix":"","firstName":"Zhewu","middleName":"","lastName":"Chen","suffix":""},{"id":498064865,"identity":"ff8e4ba0-3666-4a87-8ef4-f2562642a5b6","order_by":3,"name":"Kaijie Shen","email":"","orcid":"","institution":"Hunan University of Science and Technology","correspondingAuthor":false,"prefix":"","firstName":"Kaijie","middleName":"","lastName":"Shen","suffix":""},{"id":498064866,"identity":"18f8dda2-08bf-49c6-9c98-689a853284b6","order_by":4,"name":"Hong Huang","email":"","orcid":"","institution":"Hunan Engineering University","correspondingAuthor":false,"prefix":"","firstName":"Hong","middleName":"","lastName":"Huang","suffix":""}],"badges":[],"createdAt":"2025-07-10 10:08:28","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-7091758/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-7091758/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":99700774,"identity":"9ec8d91a-1be2-4d2f-adf1-ff461eddb997","added_by":"auto","created_at":"2026-01-07 11:40:30","extension":"pdf","order_by":1,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1214394,"visible":true,"origin":"","legend":"","description":"","filename":"AFiducialMarkerBasedLocalizationMethodforAutomotiveChassisBoltAssembly.pdf","url":"https://assets-eu.researchsquare.com/files/rs-7091758/v1_covered_c9266488-6d0b-47af-a3ed-7e967e588074.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"A Fiducial-Marker-Based Localization Method for Automotive Chassis Bolt Assembly","fulltext":[],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":false,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":true,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":true,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"Automotive chassis bolt assembly, Visual localization method, Retinex model, Ellipse fitting, Leitz criterion","lastPublishedDoi":"10.21203/rs.3.rs-7091758/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-7091758/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eTo address the difficulty of accurately localizing automotive chassis bolts during the assembly process\u0026mdash;caused by non-uniform illumination, limited camera installation space, and occlusions from the vehicle body structure\u0026mdash;a fiducial-marker-based localization method is proposed. In this method, a concentric ring-shaped fiducial marker is affixed to the bottom of the assembly wrench, and its region of interest (ROI) is extracted using an HSV color space segmentation algorithm. To overcome interference from uneven lighting and insufficient brightness in industrial environments, an improved Retinex-based image enhancement algorithm is introduced, which significantly improves the robustness and accuracy of ROI extraction. The extracted ROI image is subjected to ellipse fitting, and the fitting process is optimized by incorporating the Leitz criterion. Experimental results show that the optimized ellipse fitting algorithm achieves higher accuracy and significantly enhances the reliability of fitting. Since perspective projection of spatial circles leads to displacement of the circle center, the actual projected center of the fiducial marker in the image is calculated by estimating the normal vector of the circular plane using vanishing lines and the ellipse parameter matrix. This enables spatial localization of the bolt end. The proposed method is validated by comparing the localization results with the theoretical coordinates of the bolt holes. Experimental results demonstrate that the method offers high localization accuracy and strong robustness, meeting the practical precision requirements for automatic bolt assembly in industrial applications.\u003c/p\u003e","manuscriptTitle":"A Fiducial-Marker-Based Localization Method for Automotive Chassis Bolt Assembly","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-08-11 07:30:10","doi":"10.21203/rs.3.rs-7091758/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"c0c34866-b377-4f75-8049-c5ad6d185f93","owner":[],"postedDate":"August 11th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[{"id":52910757,"name":"Physical sciences/Engineering"},{"id":52910758,"name":"Physical sciences/Mathematics and computing"}],"tags":[],"updatedAt":"2026-01-07T11:40:13+00:00","versionOfRecord":[],"versionCreatedAt":"2025-08-11 07:30:10","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-7091758","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-7091758","identity":"rs-7091758","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}