Fuzzy Enhanced Adaptive Admittance Control of a Wearable Walking Exoskeleton With Step Trajectory Shaping

Authors

Pengbo Huang, University of Science and Technology of China
Zhijun Li, University of Science and Technology of China
Meng Chu Zhou, Newark College of Engineering
Xiang Li, University of Science and Technology of China
Mengyue Cheng, University of Science and Technology of China

Document Type

Article

Publication Date

6-1-2022

Abstract

The generation of motor adaptation in response to mechanical perturbation during human walking is seldom considered in an exoskeleton system. Reshaping step trajectory over consecutive gait cycles for a walking exoskeleton is investigated in this article. Step adjustment of a walking exoskeleton can adapt to human walking intention by shaping step trajectory. This work develops an admittance adaptive fuzzy control strategy for a walking exoskeleton robot to provide assistance for human lower limb movement. Considering human walking intention and utilizing an admittance model, it shapes a reference trajectory to ensure that the walking exoskeleton follows it according to the human-robot force produced by its wearer. Considering a nonlinear and dynamic model with uncertainties, this work designs an integral-type Lyapunov function controller to track a reference trajectory. A disturbance observer is integrated into the controller design to compensate for uncertain disturbance in order to achieve an effective tracking performance. Finally, this work conducts experiments on two healthy subjects with the proposed method on a walking exoskeleton to validate its effectiveness. The results show that it can be applied to walking exoskeletons to enhance human mobility.

Identifier

85127535522 (Scopus)

Publication Title

IEEE Transactions on Fuzzy Systems

External Full Text Location

https://doi.org/10.1109/TFUZZ.2022.3162700

e-ISSN

19410034

ISSN

10636706

First Page

1541

Last Page

1552

Issue

6

Volume

30

Recommended Citation

Huang, Pengbo; Li, Zhijun; Zhou, Meng Chu; Li, Xiang; and Cheng, Mengyue, "Fuzzy Enhanced Adaptive Admittance Control of a Wearable Walking Exoskeleton With Step Trajectory Shaping" (2022). Faculty Publications. 2932.
https://digitalcommons.njit.edu/fac_pubs/2932