Wang, T, Lin, YH, Spyrakos-Papastavridis, E et al. (2 more authors) (2023) Stiffness evaluation of a novel ankle rehabilitation exoskeleton with a type-variable constraint. Mechanism and Machine Theory, 179. ISSN 0094-114X
Abstract
This paper presents a novel ankle rehabilitation exoskeleton with two rotational degrees of freedom, which is suitable for dynamical rehabilitation for patients with neurological impairments. Its stiffness performance is assessed in consideration that the interaction between the footplate and the ground may deflect the mechanism away from the desired/predefined motion patterns. The novel design employs a universal-prismatic-universal (U-P-U) joint link, whose constraint type changes between a couple and a line vector during manipulation of the exoskeleton. To conduct a stiffness analysis of such a mechanism with a type-variable constraint – for the first time – a modified screw-based method (SBM) is proposed. Comparisons with the results obtained from finite element analysis verified that, the modified SBM provides reliable estimates of the exoskeleton's stiffness within the complete workspace (covering the constraint-type transition configurations). The stiffness of the exoskeleton is further evaluated by acquiring the minimum/maximum stiffness values, after computing the distribution of the most crucial linear and angular stiffness parameters within the workspace. Moreover, the influence of the architectural parameters on the stiffness properties is considered for further design optimization.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2022 The Author(s). Published by Elsevier Ltd. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/). |
Keywords: | Ankle rehabilitation exoskeleton; Stiffness analysis; Type-variable constraint; Transition configurations |
Dates: |
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Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Engineering & Physical Sciences (Leeds) > School of Electronic & Electrical Engineering (Leeds) > Robotics, Autonomous Systems & Sensing (Leeds) |
Funding Information: | Funder Grant number EPSRC (Engineering and Physical Sciences Research Council) EP/S019219/1 |
Depositing User: | Symplectic Publications |
Date Deposited: | 02 Nov 2022 15:40 |
Last Modified: | 02 Nov 2022 15:40 |
Status: | Published |
Publisher: | Elsevier |
Identification Number: | 10.1016/j.mechmachtheory.2022.105071 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:192563 |