2026-09-19T10:12:20Zhttps://dspace.mit.edu/server/oai/requestoai:dspace.mit.edu:1721.1/1034822026-06-17T14:46:34Zcom_1721.1_7582com_1721.1_7581col_1721.1_131022
Hugh M. Herr.
Mooney, Luke Matthewson
Massachusetts Institute of Technology. Department of Mechanical Engineering.
Massachusetts Institute of Technology. Department of Mechanical Engineering
2016-07-01T18:44:18Z
2016-07-01T18:44:18Z
2016
2016
http://hdl.handle.net/1721.1/103482
952346529
Thesis: Ph. D., Massachusetts Institute of Technology, Department of Mechanical Engineering, 2016.
Cataloged from PDF version of thesis.
Includes bibliographical references (pages 141-145).
For over a century, technologists have strived to develop autonomous leg exoskeletons that reduce the metabolic energy consumed when humans walk and run, but such technologies have traditionally remained unachievable. In this thesis, I present the Augmentation Factor, a simple model that predicts the metabolic impact of lower limb exoskeletons during walking. The Augmentation Factor balances the benefits of positive exoskeletal mechanical power with the costs of mechanical power dissipation and added limb mass. These insights were used to design and develop an autonomous powered ankle exoskeleton. A lightweight electric actuator mounted on the lower-leg provides mechanical assistance to the ankle during powered plantar flexion. Use of the exoskeleton significantly reduced the metabolic cost of walking by 11 ± 4% (p = 0.019) compared to walking without the device. In a separate study, use of the exoskeleton reduced the metabolic cost of walking with a 23 kg weighted vest by 8 ± 3% (p = 0.012). A biomechanical study revealed that the powered ankle exoskeleton does not simply replace ankle function, but augments the biological ankle while assisting the knee and hip. Use of the powered ankle exoskeleton was shown to significantly reduced the mean positive power of the biological ankle by 0.033 ± 0.006 W/kg (p<0.01), the knee by 0.042 ± 0.015 W/kg (p = 0.02), and the hip by 0.034 ± 0.009 W/kg (p<0.01). The Augmentation Factor was used to unify the results of the presented devices with the metabolic impacts of previous exoskeletons from literature. In the design of leg exoskeletons, this thesis underscores the importance of minimizing exoskeletal power dissipation and added limb mass, while providing substantial positive power to a walking human. These design requirements were used to develop the first autonomous exoskeleton to reduce the metabolic cost of walking.
by Luke Matthewson Mooney.
Ph.D.
145 pages
eng
Massachusetts Institute of Technology
M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission.
http://dspace.mit.edu/handle/1721.1/7582
Mechanical Engineering.
Autonomous powered exoskeleton to improve the efficiency of human walking
Thesis
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<Abstract>For over a century, technologists have strived to develop autonomous leg exoskeletons that reduce the metabolic energy consumed when humans walk and run, but such technologies have traditionally remained unachievable. In this thesis, I present the Augmentation Factor, a simple model that predicts the metabolic impact of lower limb exoskeletons during walking. The Augmentation Factor balances the benefits of positive exoskeletal mechanical power with the costs of mechanical power dissipation and added limb mass. These insights were used to design and develop an autonomous powered ankle exoskeleton. A lightweight electric actuator mounted on the lower-leg provides mechanical assistance to the ankle during powered plantar flexion. Use of the exoskeleton significantly reduced the metabolic cost of walking by 11 ± 4% (p = 0.019) compared to walking without the device. In a separate study, use of the exoskeleton reduced the metabolic cost of walking with a 23 kg weighted vest by 8 ± 3% (p = 0.012). A biomechanical study revealed that the powered ankle exoskeleton does not simply replace ankle function, but augments the biological ankle while assisting the knee and hip. Use of the powered ankle exoskeleton was shown to significantly reduced the mean positive power of the biological ankle by 0.033 ± 0.006 W/kg (p<0.01), the knee by 0.042 ± 0.015 W/kg (p = 0.02), and the hip by 0.034 ± 0.009 W/kg (p<0.01). The Augmentation Factor was used to unify the results of the presented devices with the metabolic impacts of previous exoskeletons from literature. In the design of leg exoskeletons, this thesis underscores the importance of minimizing exoskeletal power dissipation and added limb mass, while providing substantial positive power to a walking human. These design requirements were used to develop the first autonomous exoskeleton to reduce the metabolic cost of walking.</Abstract>
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