Design and development of a compact small-scale spherical gear mechanism with manipulability-based singularity avoidance

Design and development of a compact small-scale spherical gear mechanism with manipulability-based singularity avoidance | 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 Design and development of a compact small-scale spherical gear mechanism with manipulability-based singularity avoidance Moses Gladson Selvamuthu, Kazuki Abe, Kenjiro Tadakuma, Riichiro Tadakuma This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-6660628/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 08 Jan, 2026 Read the published version in ROBOMECH Journal → Version 1 posted 9 You are reading this latest preprint version Abstract Multi-degree of freedom (DOF) robotic systems, particularly those with seven or more DOFs similar to the human arm, have the potential to significantly expand the functional range and versatility of robotic manipulators. The spherical gear mechanism, known as ABENICS, serves as a novel joint element that enables the integration of multiple rotational axes at a single point, resulting in a more compact structure with increased degrees of freedom. This study focuses on the design and validation of a miniaturized spherical gear mechanism, featuring a spherical gear with a module of 1.5 mm and an outer diameter of 51 mm. The study discusses its mechanical design, operational performance, and manipulability-based motion control strategy for effective singularity avoidance. Furthermore, a driving gear-based angular feedback system utilizing hall-effect sensors is introduced for homing, demonstrating improved performance and reliability compared to the previously implemented IMU-based homing approach. Experiments were conducted to assess the mechanism’s motion range, positional error, singularity avoidance, and homing performance, all of which were successfully validated. The results confirm the potential of this miniaturized mechanism to enable more compact , efficient, and functional robotic systems. Finally, the study demonstrates the application of the developed mechanism as a wrist joint capable of carrying a payload of 200 g. Spherical gear mechanism multi-DOF joint compact wrist joint singularity avoidance 1 Introduction Over the Full Text Additional Declarations No competing interests reported. Supplementary Files ABENICS1.5.mp4 Cite Share Download PDF Status: Published Journal Publication published 08 Jan, 2026 Read the published version in ROBOMECH Journal → Version 1 posted Editorial decision: Revision requested 02 Jul, 2025 Reviews received at journal 27 Jun, 2025 Reviews received at journal 26 Jun, 2025 Reviewers agreed at journal 27 May, 2025 Reviewers agreed at journal 19 May, 2025 Reviewers invited by journal 19 May, 2025 Editor assigned by journal 17 May, 2025 Submission checks completed at journal 17 May, 2025 First submitted to journal 14 May, 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. 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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-6660628","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":458991659,"identity":"11cfcb7e-13d1-45f2-a33e-51e5d3777a61","order_by":0,"name":"Moses Gladson 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