Simulating the Dynamics of a Human-Exoskeleton System Using Kinematic Data with Misalignment Between the Human and Exoskeleton Joints: Selected Papers from the 17th International Symposium CMBBE and 5th Conference on Imagining and Visualization September 7-9, 2021

Divyaksh Subhash Chander, Max Böhme, Michael Skipper Andersen, John Rasmussen, Maria Pia Cavatorta

Research output: Contribution to book/anthology/report/conference proceedingBook chapterResearchpeer-review

1 Citation (Scopus)

Abstract

Musculoskeletal model-based simulation can be a powerful tool in the evaluation of exoskeletons. An ideal exoskeleton model, perfectly aligned with the human joint axes, can be used to co-simulate the human and exoskeleton dynamics. However, human-exoskeleton joint misalignment is commonly observed during the use of an exoskeleton. Using misaligned motion data in the combined human-exoskeleton model can lead to unrealistic results. In this work, we present a new method to align human-exoskeleton models. This was achieved by introducing dummy segments that ensured kinetic alignment between the human and exoskeleton joints without altering the misaligned kinematics. The method was applied on an active lower-limb exoskeleton that assists the elderly in stair negotiation. In a pilot study, motion data of a single subject testing the exoskeleton in stair ascent were recorded using an optical marker-based system. Measured ground reaction force and exoskeleton assistive force were used as inputs in the human-exoskeleton model. The outputs from the model with the dummy segments were compared to those from a model with kinematic constraints and a reference model where the external forces were applied directly to the human model. The results of the knee compression force, knee flexion moment, and activation of vastus lateralis showed good agreement between the dummy segments and reference models. The use of the dummy segments allows the study of aligned kinetics and misaligned kinematics from the same model. The method will be used in a future study to evaluate the exoskeleton with more subjects.
Original languageEnglish
Title of host publicationComputer Methods, Imaging and Visualization in Biomechanics and Biomedical Engineering II
EditorsJoão Manuel R. S. Tavares, Christoph Bourauel, Liesbet Geris, Jos Vander Slote
Number of pages9
Volume38
PublisherSpringer
Publication date2022
Pages65-73
ISBN (Print)978-3-031-10014-7
ISBN (Electronic)978-3-031-10015-4
DOIs
Publication statusPublished - 2022
EventInternational Symposium on Computer Methods in Biomechanics and Biomedical Engineering - Bonn, Germany
Duration: 7 Sept 20219 Sept 2021
Conference number: 17
https://www.cmbbe-symposium.com/2021/

Conference

ConferenceInternational Symposium on Computer Methods in Biomechanics and Biomedical Engineering
Number17
Country/TerritoryGermany
CityBonn
Period07/09/202109/09/2021
Internet address

Keywords

  • Human-exoskeleton interface
  • Musculoskeletal model
  • Contact model

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