There are several methods to simulate the human-exoskeleton interface but there is insufficient evidence regarding the choice of the method. This work compares two rigid-body methods to simulate the interface: 1) optimisation-based contact forces; 2) reaction forces at a point on the interface. Additionally, a method to kinetically align the human-exoskeleton joint axes is presented. A single subject tested an active lower limb exoskeleton in stair ascent. The biomechanical outputs were compared to a baseline model, where the measured assistive and ground reaction forces were applied directly to the human model. Both methods showed negligible differences in knee compression force, knee flexion moment, and vastus lateralis activation. However, the ankle outputs showed some differences between the methods. Computationally expensive contact forces provided six-axis interface forces unlike reaction forces, which were limited to the number of constraints required by the exoskeleton. Future studies could compare rigid-body and viscoelastic models.

A comparison of different methods for modelling the physical human-exoskeleton interface / Chander, D. S.; Böhme, M.; Andersen, M. S.; Rasmussen, J.; Zentner, J.; Cavatorta, M. P.. - In: INTERNATIONAL JOURNAL OF HUMAN FACTORS MODELLING AND SIMULATION. - ISSN 1742-5557. - ELETTRONICO. - 7:(2022), pp. 204-230.

A comparison of different methods for modelling the physical human-exoskeleton interface

Chander D. S.;Cavatorta M. P.
2022

Abstract

There are several methods to simulate the human-exoskeleton interface but there is insufficient evidence regarding the choice of the method. This work compares two rigid-body methods to simulate the interface: 1) optimisation-based contact forces; 2) reaction forces at a point on the interface. Additionally, a method to kinetically align the human-exoskeleton joint axes is presented. A single subject tested an active lower limb exoskeleton in stair ascent. The biomechanical outputs were compared to a baseline model, where the measured assistive and ground reaction forces were applied directly to the human model. Both methods showed negligible differences in knee compression force, knee flexion moment, and vastus lateralis activation. However, the ankle outputs showed some differences between the methods. Computationally expensive contact forces provided six-axis interface forces unlike reaction forces, which were limited to the number of constraints required by the exoskeleton. Future studies could compare rigid-body and viscoelastic models.
File in questo prodotto:
Non ci sono file associati a questo prodotto.
Pubblicazioni consigliate

Caricamento pubblicazioni consigliate

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: http://hdl.handle.net/11583/2969533
 Attenzione

Attenzione! I dati visualizzati non sono stati sottoposti a validazione da parte dell'ateneo