{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,25]],"date-time":"2026-06-25T02:44:33Z","timestamp":1782355473203,"version":"3.54.5"},"reference-count":17,"publisher":"SAGE Publications","issue":"7","license":[{"start":{"date-parts":[[2001,7,1]],"date-time":"2001-07-01T00:00:00Z","timestamp":993945600000},"content-version":"tdm","delay-in-days":0,"URL":"https:\/\/journals.sagepub.com\/page\/policies\/text-and-data-mining-license"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["The International Journal of Robotics Research"],"published-print":{"date-parts":[[2001,7]]},"abstract":"<jats:p>The authors have built the first three-dimensional, kneed, two-legged, passive-dynamic walking machine. Since the work of Tad McGeer in the late 1980s, the concept of passive dynamics has added insight into animal locomotion and the design of anthropomorphic robots. Various analyses and machines that demonstrate efficient human-like walking have been developed using this strategy. Human-like passive machines, however, have only operated in two dimensions (i.e., within the fore-aft or sagittal plane). Three-dimensional passive walking devices, mostly toys, have not had human-like motions but instead a stiff legged waddle. In the present three-dimensional device, the authors preserve features of McGeer\u2019s two-dimensional models, including mechanical simplicity, human-like knee flexure, and passive gravitational power from descending a shallow slope. They then add specially curved feet, a compliant heel, and mechanically constrained arms to achieve a harmonious and stable gait. The device stands 85 cm tall. It weighs 4.8 kg, walks at about 0.51 m\/s down a 3.1-degree slope, and consumes 1.3 W. This robot further implicates passive dynamics in human walking and may help point the way toward simple and efficient robots with human-like motions.<\/jats:p>","DOI":"10.1177\/02783640122067561","type":"journal-article","created":{"date-parts":[[2003,7,19]],"date-time":"2003-07-19T01:53:44Z","timestamp":1058579624000},"page":"607-615","source":"Crossref","is-referenced-by-count":608,"title":["A Three-Dimensional Passive-Dynamic Walking Robot with Two Legs and Knees"],"prefix":"10.1177","volume":"20","author":[{"given":"Steven H.","family":"Collins","sequence":"first","affiliation":[{"name":"Mechanical and Aerospace Engineering, Cornell University, Ithaca, NY                         14853, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Martijn","family":"Wisse","sequence":"additional","affiliation":[{"name":"Man-Machine Systems and Control, Delft University of Technology, Mekelweg                         2, NL-2628 CD Delft, the Netherlands"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Andy","family":"Ruina","sequence":"additional","affiliation":[{"name":"Theoretical and Applied Mechanics, Mechanical and Aerospace Engineering,                         Cornell University, Ithaca, NY 14853, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"179","published-online":{"date-parts":[[2001,7,1]]},"reference":[{"key":"atypb1","unstructured":"Adolfsson, J., Dankowicz, H., and Nordmark, A. 2001. 3D passive walkers: Finding periodic gaits in the presence of discontinuities. Nonlinear Dynamics, forthcoming."},{"key":"atypb2","unstructured":"Bechstein, B. U. 1912. Improvements in and relating to toys. U.K. Patent No. 7453."},{"key":"atypb3","doi-asserted-by":"publisher","DOI":"10.1103\/PhysRevLett.80.3658"},{"key":"atypb4","unstructured":"Elftman, H. 1939. The function of arms in walking . Human Biology 11: 529\u2013535 ."},{"key":"atypb5","unstructured":"Fallis, G. T. 1888. Walking toy. U.S. Patent No. 376588."},{"key":"atypb6","doi-asserted-by":"publisher","DOI":"10.1080\/713603737"},{"key":"atypb7","doi-asserted-by":"crossref","unstructured":"Hirai, K., Hirose, M., Haikawa, Y., and Takenaka, T. 1998. The development of the Honda Humanoid robot . IEEE International Conference on Robotics and Automation Proceedings, Leuven, Belgium, May, pp. 1321\u20131326 .","DOI":"10.1109\/ROBOT.1998.677288"},{"key":"atypb8","unstructured":"Honda. 2000. Honda Humanoid robot specifications. Available at: http:\/\/world.honda.com\/robot."},{"key":"atypb9","doi-asserted-by":"publisher","DOI":"10.1177\/02783649922066655"},{"key":"atypb10","unstructured":"Mahon, J. J. 1914. Walking toy. U.S. Patent No. 1007316, Serial Nos. 541801 and 796095."},{"key":"atypb11","doi-asserted-by":"publisher","DOI":"10.1177\/027836499000900206"},{"key":"atypb12","unstructured":"McGeer, T. 1991. Passive dynamic biped catalogue. In Proceedings of the 2nd International Symposium of Experimental Robotics. New York: Springer-Verlag ."},{"key":"atypb13","doi-asserted-by":"crossref","unstructured":"Mombaur, K., Coleman, M. J., Garcia, M., and Ruina, A. 2001. Prediction of stable walking for a toy that cannot stand still . Physical Review E 64(2), forthcoming.","DOI":"10.1103\/PhysRevE.64.022901"},{"key":"atypb14","unstructured":"Pratt, J. 2000. Exploiting inherent robustness and natural dynamics in the control of bipedal walking robots. Ph.D. thesis, Massachusetts Institute of Technology."},{"key":"atypb15","unstructured":"Pratt, J., and Pratt, G. 1999. Exploiting natural dynamics in the control of a 3D bipedal walking simulation . Proceedings of the International Conference on Climbing and Walking Robots. Portsmouth, United Kingdom, September."},{"key":"atypb16","unstructured":"Wilson, J. E. 1938. Walking toy. U.S. Patent No. 2140275."},{"key":"atypb17","doi-asserted-by":"publisher","DOI":"10.1017\/S0263574700003040"}],"container-title":["The International Journal of Robotics Research"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/journals.sagepub.com\/doi\/pdf\/10.1177\/02783640122067561","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/journals.sagepub.com\/doi\/pdf\/10.1177\/02783640122067561","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,4,29]],"date-time":"2026-04-29T10:16:37Z","timestamp":1777457797000},"score":1,"resource":{"primary":{"URL":"https:\/\/journals.sagepub.com\/doi\/10.1177\/02783640122067561"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2001,7]]},"references-count":17,"journal-issue":{"issue":"7","published-print":{"date-parts":[[2001,7]]}},"alternative-id":["10.1177\/02783640122067561"],"URL":"https:\/\/doi.org\/10.1177\/02783640122067561","relation":{},"ISSN":["0278-3649","1741-3176"],"issn-type":[{"value":"0278-3649","type":"print"},{"value":"1741-3176","type":"electronic"}],"subject":[],"published":{"date-parts":[[2001,7]]}}}