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Model-Based Adaptive Control of Transfemoral Prostheses: Theory, Simulation, and Experiments

Azimi, Vahid and Shu, Tony and Zhao, Huihua and Gehlhar, Rachel and Simon, Dan and Ames, Aaron D. (2021) Model-Based Adaptive Control of Transfemoral Prostheses: Theory, Simulation, and Experiments. IEEE Transactions on Systems, Man, and Cybernetics: Systems, 51 (2). pp. 1174-1191. ISSN 2168-2216. doi:10.1109/TSMC.2019.2896193.

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This paper presents and experimentally implements three different adaptive and robust adaptive controllers as the first steps toward using model-based controllers for transfemoral prostheses. The goal of this paper is to translate these control methods to the robotic domain, from bipedal robotic walking to prosthesis walking, including a rigorous stability analysis. The human/prosthesis system is first modeled as a two-domain hybrid asymmetric system. An optimization problem is formulated to obtain a stable human-like gait. The proposed controllers are then developed for the combined human/prosthesis model and the optimized reference gait. The stability of all three controllers is proven using the Lyapunov stability theorem, ensuring convergence to the desired gait. The proposed controllers are first verified on a bipedal walking robot as a hybrid human/prosthesis model in simulation. They are then experimentally tested on a treadmill with an able-bodied subject using third iteration of AMBER Prosthetic (AMPRO3), a custom self-contained powered transfemoral prosthesis. Finally, outdoor tests are carried out using AMPRO3 with three test subjects walking on level ground, uphill slopes, and downhill slopes at slope angles of 3° and 8°, to demonstrate walking in different real-world environments.

Item Type:Article
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URLURL TypeDescription
Azimi, Vahid0000-0002-5694-3871
Gehlhar, Rachel0000-0002-4838-8839
Simon, Dan0000-0002-1289-4000
Ames, Aaron D.0000-0003-0848-3177
Additional Information:© 2019 IEEE. Manuscript received November 25, 2018; accepted January 20, 2019. Date of publication February 15, 2019; date of current version January 19, 2021. This work was supported by NSF under Award NRI-1526519 and Grant 1344954. This paper was recommended by Associate Editor Z. Li. The authors are indebted to J. Reher for his help on the outdoor experimental tests. They would like to thank E. Ambrose for designing and building the prosthesis device AMPRO3. They would also like to thank the Editor and reviewers for their helpful comments and suggestions. This research was approved by the Georgia Institute of Technology and the California Institute of Technology Institutional Review Boards, protocol numbers H15255 and 16-0693, for testing with humans.
Funding AgencyGrant Number
Subject Keywords:Adaptive and robust adaptive control, hybrid system, transfemoral prosthesis, walking biped
Issue or Number:2
Record Number:CaltechAUTHORS:20190222-102105621
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Official Citation:V. Azimi, T. Shu, H. Zhao, R. Gehlhar, D. Simon and A. D. Ames, "Model-Based Adaptive Control of Transfemoral Prostheses: Theory, Simulation, and Experiments," in IEEE Transactions on Systems, Man, and Cybernetics: Systems, vol. 51, no. 2, pp. 1174-1191, Feb. 2021, doi: 10.1109/TSMC.2019.2896193
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:93181
Deposited By: Tony Diaz
Deposited On:25 Feb 2019 17:07
Last Modified:16 Nov 2021 16:56

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