Metastable Walking Machines
Legged robots that operate in the real world are inherently subject to stochasticity in their dynamics and uncertainty about the terrain. Owing to limited energy budgets and limited control authority, these “disturbances” cannot always be canceled out with high-gain feedback. Minimally actuated walk...
| Main Authors: | , |
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| Format: | Article |
| Language: | en_US |
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Sage
2011
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| Online Access: | http://hdl.handle.net/1721.1/61973 https://orcid.org/0000-0002-8712-7092 |
| _version_ | 1826191574538649600 |
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| author | Byl, Katie Tedrake, Russell Louis |
| author2 | Massachusetts Institute of Technology. Computer Science and Artificial Intelligence Laboratory |
| author_facet | Massachusetts Institute of Technology. Computer Science and Artificial Intelligence Laboratory Byl, Katie Tedrake, Russell Louis |
| author_sort | Byl, Katie |
| collection | MIT |
| description | Legged robots that operate in the real world are inherently subject to stochasticity in their dynamics and uncertainty about the terrain. Owing to limited energy budgets and limited control authority, these “disturbances” cannot always be canceled out with high-gain feedback. Minimally actuated walking machines subject to stochastic disturbances no longer satisfy strict conditions for limit-cycle stability; however, they can still demonstrate impressively long-living periods of continuous walking. Here, we employ tools from stochastic processes to examine the “stochastic stability” of idealized rimless-wheel and compass-gait walking on randomly generated uneven terrain. Furthermore, we employ tools from numerical stochastic optimal control to design a controller for an actuated compass gait model which maximizes a measure of stochastic stability—the mean first-passage time—and compare its performance with a deterministic counterpart. Our results demonstrate that walking is well characterized as a metastable process, and that the stochastic dynamics of walking should be accounted for during control design in order to improve the stability of our machines. |
| first_indexed | 2024-09-23T08:58:02Z |
| format | Article |
| id | mit-1721.1/61973 |
| institution | Massachusetts Institute of Technology |
| language | en_US |
| last_indexed | 2024-09-23T08:58:02Z |
| publishDate | 2011 |
| publisher | Sage |
| record_format | dspace |
| spelling | mit-1721.1/619732022-09-26T09:30:39Z Metastable Walking Machines Byl, Katie Tedrake, Russell Louis Massachusetts Institute of Technology. Computer Science and Artificial Intelligence Laboratory Massachusetts Institute of Technology. Department of Electrical Engineering and Computer Science Tedrake, Russell Louis Byl, Katie Tedrake, Russell Louis Legged robots that operate in the real world are inherently subject to stochasticity in their dynamics and uncertainty about the terrain. Owing to limited energy budgets and limited control authority, these “disturbances” cannot always be canceled out with high-gain feedback. Minimally actuated walking machines subject to stochastic disturbances no longer satisfy strict conditions for limit-cycle stability; however, they can still demonstrate impressively long-living periods of continuous walking. Here, we employ tools from stochastic processes to examine the “stochastic stability” of idealized rimless-wheel and compass-gait walking on randomly generated uneven terrain. Furthermore, we employ tools from numerical stochastic optimal control to design a controller for an actuated compass gait model which maximizes a measure of stochastic stability—the mean first-passage time—and compare its performance with a deterministic counterpart. Our results demonstrate that walking is well characterized as a metastable process, and that the stochastic dynamics of walking should be accounted for during control design in order to improve the stability of our machines. 2011-03-25T19:54:51Z 2011-03-25T19:54:51Z 2009-06 Article http://purl.org/eprint/type/JournalArticle 0278-3649 1741-3176 http://hdl.handle.net/1721.1/61973 Byl, Katie, and Russ Tedrake. “Metastable Walking Machines.” The International Journal Of Robotics Research 28.8 (2009) : 1040 -1064. Copyright © 2009, SAGE Publications https://orcid.org/0000-0002-8712-7092 en_US http://dx.doi.org/10.1177/0278364909340446 International journal of robotics research Creative Commons Attribution-Noncommercial-Share Alike 3.0 http://creativecommons.org/licenses/by-nc-sa/3.0/ application/pdf Sage MIT web domain |
| spellingShingle | Byl, Katie Tedrake, Russell Louis Metastable Walking Machines |
| title | Metastable Walking Machines |
| title_full | Metastable Walking Machines |
| title_fullStr | Metastable Walking Machines |
| title_full_unstemmed | Metastable Walking Machines |
| title_short | Metastable Walking Machines |
| title_sort | metastable walking machines |
| url | http://hdl.handle.net/1721.1/61973 https://orcid.org/0000-0002-8712-7092 |
| work_keys_str_mv | AT bylkatie metastablewalkingmachines AT tedrakerusselllouis metastablewalkingmachines |