{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,7]],"date-time":"2026-03-07T11:53:01Z","timestamp":1772884381031,"version":"3.50.1"},"reference-count":28,"publisher":"Springer Science and Business Media LLC","issue":"1","license":[{"start":{"date-parts":[[2025,8,5]],"date-time":"2025-08-05T00:00:00Z","timestamp":1754352000000},"content-version":"tdm","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0"},{"start":{"date-parts":[[2025,8,5]],"date-time":"2025-08-05T00:00:00Z","timestamp":1754352000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0"}],"funder":[{"DOI":"10.13039\/100010661","name":"Horizon 2020 Framework Programme","doi-asserted-by":"publisher","award":["101016970"],"award-info":[{"award-number":["101016970"]}],"id":[{"id":"10.13039\/100010661","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":["link.springer.com"],"crossmark-restriction":false},"short-container-title":["Sci Rep"],"abstract":"<jats:title>Abstract<\/jats:title>\n          <jats:p>This paper investigates how a new angle-dependent damper design can help a robot to reduce collision forces. We designed a fluid-viscous angle-dependent damper by smoothly changing the clearance between the stationary and moving parts. Analytical and numerical simulation-based predictions were experimentally tested. Analytical modelling shows that angle-dependent damping has a <jats:inline-formula>\n              <jats:tex-math>$$48\\%$$<\/jats:tex-math>\n            <\/jats:inline-formula> reduction in peak forces when compared to constant damping. Numerical simulations show that variable-gap dampers can change damping by <jats:inline-formula>\n              <jats:tex-math>$$134 \\times$$<\/jats:tex-math>\n            <\/jats:inline-formula> during a <jats:inline-formula>\n              <jats:tex-math>$$10 \\times$$<\/jats:tex-math>\n            <\/jats:inline-formula> gap change. The experimental findings confirm the analytical predictions by reducing collision force by up to <jats:inline-formula>\n              <jats:tex-math>$$10\\%$$<\/jats:tex-math>\n            <\/jats:inline-formula>. These findings suggest that the angle-dependent variable damping solution could be used for robots that experience collisions such as industrial robotic manipulators, legged robots, perching robots, or robots that catch moving objects.<\/jats:p>","DOI":"10.1038\/s41598-025-13055-7","type":"journal-article","created":{"date-parts":[[2025,8,5]],"date-time":"2025-08-05T14:01:19Z","timestamp":1754402479000},"update-policy":"https:\/\/doi.org\/10.1007\/springer_crossmark_policy","source":"Crossref","is-referenced-by-count":1,"title":["Joints with angle dependent damping can help to reduce impact forces in robots"],"prefix":"10.1038","volume":"15","author":[{"given":"Shehara","family":"Perera","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Saeed","family":"Bornassi","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Mazdak","family":"Ghajari","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Thrishantha","family":"Nanayakkara","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"297","published-online":{"date-parts":[[2025,8,5]]},"reference":[{"key":"13055_CR1","doi-asserted-by":"crossref","unstructured":"Seok, S. et al. Design principles for highly efficient quadrupeds and implementation on the mit cheetah robot. In 2013 IEEE International Conference on Robotics and Automation, 3307\u20133312 (IEEE, 2013).","DOI":"10.1109\/ICRA.2013.6631038"},{"key":"13055_CR2","doi-asserted-by":"crossref","unstructured":"Hutter, M. et al. Anymal-a highly mobile and dynamic quadrupedal robot. In 2016 IEEE\/RSJ International Conference on Intelligent Robots and Systems (IROS), 38\u201344 (IEEE, 2016).","DOI":"10.1109\/IROS.2016.7758092"},{"key":"13055_CR3","doi-asserted-by":"crossref","unstructured":"He, T. et al. Agile but safe: Learning collision-free high-speed legged locomotion. In Robotics, Science and Systems (RSS) (2024).","DOI":"10.15607\/RSS.2024.XX.059"},{"key":"13055_CR4","doi-asserted-by":"publisher","first-page":"eabj7562","DOI":"10.1126\/scirobotics.abj7562","volume":"6","author":"WR Roderick","year":"2021","unstructured":"Roderick, W. R., Cutkosky, M. R. & Lentink, D. Bird-inspired dynamic grasping and perching in arboreal environments. Sci. Robot. 6, eabj7562 (2021).","journal-title":"Sci. Robot."},{"key":"13055_CR5","doi-asserted-by":"crossref","unstructured":"Yan, L. et al. Impact-aware bimanual catching of large-momentum objects. IEEE Trans. Robot. (2024).","DOI":"10.1109\/TRO.2024.3381551"},{"key":"13055_CR6","doi-asserted-by":"crossref","unstructured":"Sato, Y., Ohashi, E. & Ohnishi, K. Impact force reduction for hopping robot. In 31st Annual Conference of IEEE Industrial Electronics Society, 2005. IECON 2005 (IEEE, 2005).","DOI":"10.1109\/IECON.2005.1569182"},{"key":"13055_CR7","unstructured":"Calderon, J.\u00a0M., Llofriu, M., Moreno, W. & Weitzenfeld, A. Soft landing in jumping robot using compliant motor capability. In Workshop Get in touch (Citeseer, 2015)."},{"key":"13055_CR8","doi-asserted-by":"crossref","unstructured":"Choi, W., Zhou, C., Medrano-Cerda, G.\u00a0A., Caldwell, D.\u00a0G. & Tsagarakis, N.\u00a0G. A new foot sole design for humanoids robots based on viscous air damping mechanism. In 2015 IEEE\/RSJ International Conference on Intelligent Robots and Systems (IROS), 4498\u20134503 (IEEE, 2015).","DOI":"10.1109\/IROS.2015.7354016"},{"key":"13055_CR9","doi-asserted-by":"publisher","DOI":"10.1115\/1.4046834","volume":"12","author":"JJ Rond","year":"2020","unstructured":"Rond, J. J., Cardani, M. C., Campbell, M. I. & Hurst, J. W. Mitigating peak impact forces by customizing the passive foot dynamics of legged robots. J. Mech. Robot. 12, 051010 (2020).","journal-title":"J. Mech. Robot."},{"key":"13055_CR10","doi-asserted-by":"crossref","unstructured":"Choi, W., Dallali, H., Medrano-Cerda, G.\u00a0A., Tsagarakis, N.\u00a0G. & Caldwell, D.\u00a0G. How leg\/foot compliance and posture affects impact forces during landing. In 2014 IEEE International Conference on Robotics and Biomimetics (ROBIO 2014), 961\u2013967 (IEEE, 2014).","DOI":"10.1109\/ROBIO.2014.7090457"},{"key":"13055_CR11","doi-asserted-by":"publisher","first-page":"4578","DOI":"10.1109\/TRO.2024.3443714","volume":"40","author":"L Liow","year":"2024","unstructured":"Liow, L. et al. A compliant robotic leg based on fibre jamming. IEEE Trans. Rob. 40, 4578\u20134597 (2024).","journal-title":"IEEE Trans. Rob."},{"key":"13055_CR12","doi-asserted-by":"publisher","first-page":"329","DOI":"10.1163\/156855393X00203","volume":"7","author":"E Nakano","year":"1992","unstructured":"Nakano, E., Okubo, H. & Kimura, H. Landing control for a jumping machine. Adv. Robot. 7, 329\u2013342 (1992).","journal-title":"Adv. Robot."},{"key":"13055_CR13","doi-asserted-by":"crossref","unstructured":"Hyon, S.-H. & Mita, T. Development of a biologically inspired hopping robot-\u201c kenken\u201d. In Proceedings 2002 IEEE International Conference on Robotics and Automation (Cat. No. 02CH37292), vol.\u00a04, 3984\u20133991 (IEEE, 2002).","DOI":"10.1109\/ROBOT.2002.1014356"},{"key":"13055_CR14","doi-asserted-by":"crossref","unstructured":"Ohashi, E. & Ohnishi, K. Variable compliance control based on soft-landing trajectory for hopping robot. In 30th Annual Conference of IEEE Industrial Electronics Society, 2004. IECON 2004, vol.\u00a01, 117\u2013122 (IEEE, 2004).","DOI":"10.1109\/IECON.2004.1433294"},{"key":"13055_CR15","doi-asserted-by":"crossref","unstructured":"Kim, Y.-D., Lee, B.-J., Yoo, J.-K., Kim, J.-H. & Ryu, J.-H. Compensation for the landing impact force of a humanoid robot by time domain passivity approach. In Proceedings 2006 IEEE International Conference on Robotics and Automation, 2006. ICRA 2006., 1225\u20131230 (IEEE, 2006).","DOI":"10.1109\/ICSMC.2006.384800"},{"key":"13055_CR16","doi-asserted-by":"publisher","first-page":"33","DOI":"10.5772\/5686","volume":"4","author":"S Sung","year":"2007","unstructured":"Sung, S. & Youm, Y. Landing motion control of articulated hopping robot. Int. J. Adv. Rob. Syst. 4, 33 (2007).","journal-title":"Int. J. Adv. Rob. Syst."},{"key":"13055_CR17","unstructured":"Kamei, A., Jinno, M., Chishima, N., Sato, K. & Kikuchi, K. Soft landing condition for stair-climbing robot with hopping mechanism. In Proc. of the 3rd Int. Conf. on Design Engineering and Science (ICDES 2014), vol.\u00a01, 122 (2014)."},{"key":"13055_CR18","doi-asserted-by":"publisher","first-page":"3658","DOI":"10.1109\/LRA.2020.2977260","volume":"5","author":"DJ Lynch","year":"2020","unstructured":"Lynch, D. J., Lynch, K. M. & Umbanhowar, P. B. The soft-landing problem: Minimizing energy loss by a legged robot impacting yielding terrain. IEEE Robot. Autom. Lett. 5, 3658\u20133665 (2020).","journal-title":"IEEE Robot. Autom. Lett."},{"key":"13055_CR19","doi-asserted-by":"publisher","first-page":"17","DOI":"10.3390\/robotics12010017","volume":"12","author":"B Zhang","year":"2023","unstructured":"Zhang, B., Wang, L., Wang, Y. & Yuan, Z. Based on the foot-ground contact mechanics model and velocity planning buffer control. Robotics 12, 17 (2023).","journal-title":"Robotics"},{"key":"13055_CR20","doi-asserted-by":"publisher","first-page":"7634","DOI":"10.1038\/s41467-024-51568-3","volume":"15","author":"TJK Buchner","year":"2024","unstructured":"Buchner, T. J. K. et al. Electrohydraulic musculoskeletal robotic leg for agile, adaptive, yet energy-efficient locomotion. Nat. Commun. 15, 7634 (2024).","journal-title":"Nat. Commun."},{"key":"13055_CR21","unstructured":"Caijun, X., Xiuli, X. & Wengang, Q. 806. research on the performance of buffer for landing gear based on the drop test. J. Vibroeng. 14 (2012)."},{"key":"13055_CR22","doi-asserted-by":"publisher","first-page":"1901","DOI":"10.2514\/1.C034276","volume":"54","author":"Y Li","year":"2017","unstructured":"Li, Y., Jiang, J. Z., Neild, S. A. & Wang, H. Optimal inerter-based shock\u2013strut configurations for landing-gear touchdown performance. J. Aircraft 54, 1901\u20131909 (2017).","journal-title":"J. Aircraft"},{"key":"13055_CR23","doi-asserted-by":"publisher","first-page":"79","DOI":"10.12691\/ajme-7-2-4","volume":"7","author":"F Shi","year":"2019","unstructured":"Shi, F. Multi-objective optimization of passive shock absorber for landing gear. Am. J. Mech. Eng. 7, 79\u201386 (2019).","journal-title":"Am. J. Mech. Eng."},{"key":"13055_CR24","doi-asserted-by":"publisher","first-page":"107","DOI":"10.12691\/ajme-7-3-1","volume":"7","author":"F Shi","year":"2019","unstructured":"Shi, F., Dean, W. I. A. & Suyama, T. Single-objective optimization of passive shock absorber for landing gear. Am. J. Mech. Eng. 7, 107\u2013115 (2019).","journal-title":"Am. J. Mech. Eng."},{"key":"13055_CR25","first-page":"356","volume":"9","author":"DA Vencatasawmy","year":"2020","unstructured":"Vencatasawmy, D. A. & Caijun, X. Research on landing gear metering pin and analysis of its impact on the buffer performance. Int. J. Eng. Res. Technol. (IJERT) 9, 356\u2013361 (2020).","journal-title":"Int. J. Eng. Res. Technol. (IJERT)"},{"key":"13055_CR26","doi-asserted-by":"publisher","first-page":"71","DOI":"10.1016\/S0021-9290(97)00106-1","volume":"31","author":"L-Q Zhang","year":"1997","unstructured":"Zhang, L.-Q., Nuber, G., Butler, J., Bowen, M. & Rymer, W. Z. In vivo human knee joint dynamic properties as functions of muscle contraction and joint position. J. Biomech. 31, 71\u201376 (1997).","journal-title":"J. Biomech."},{"key":"13055_CR27","doi-asserted-by":"publisher","first-page":"3025","DOI":"10.1109\/LRA.2021.3062307","volume":"6","author":"E Hamid","year":"2021","unstructured":"Hamid, E., Herzig, N., Abad, S.-A. & Nanayakkara, T. A state-dependent damping method to reduce collision force and its variability. IEEE Robot. Autom. Lett. 6, 3025\u20133032 (2021).","journal-title":"IEEE Robot. Autom. Lett."},{"key":"13055_CR28","doi-asserted-by":"publisher","first-page":"eaau5872","DOI":"10.1126\/scirobotics.aau5872","volume":"4","author":"J Hwangbo","year":"2019","unstructured":"Hwangbo, J. et al. Learning agile and dynamic motor skills for legged robots. Sci. Robot. 4, eaau5872 (2019).","journal-title":"Sci. Robot."}],"container-title":["Scientific Reports"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.nature.com\/articles\/s41598-025-13055-7.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/www.nature.com\/articles\/s41598-025-13055-7","content-type":"text\/html","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/www.nature.com\/articles\/s41598-025-13055-7.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,9,8]],"date-time":"2025-09-08T18:48:55Z","timestamp":1757357335000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.nature.com\/articles\/s41598-025-13055-7"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2025,8,5]]},"references-count":28,"journal-issue":{"issue":"1","published-online":{"date-parts":[[2025,12]]}},"alternative-id":["13055"],"URL":"https:\/\/doi.org\/10.1038\/s41598-025-13055-7","relation":{},"ISSN":["2045-2322"],"issn-type":[{"value":"2045-2322","type":"electronic"}],"subject":[],"published":{"date-parts":[[2025,8,5]]},"assertion":[{"value":"18 November 2024","order":1,"name":"received","label":"Received","group":{"name":"ArticleHistory","label":"Article History"}},{"value":"21 July 2025","order":2,"name":"accepted","label":"Accepted","group":{"name":"ArticleHistory","label":"Article History"}},{"value":"5 August 2025","order":3,"name":"first_online","label":"First Online","group":{"name":"ArticleHistory","label":"Article History"}},{"order":1,"name":"Ethics","group":{"name":"EthicsHeading","label":"Declarations"}},{"value":"The authors declare no competing interests.","order":2,"name":"Ethics","group":{"name":"EthicsHeading","label":"Competing interests"}}],"article-number":"28578"}}