Modelling friction at the mechanical interface between the human and the exoskeleton. (20th February 2020)

• Record Type: Journal Article
• Authors: Chander, Divyaksh Subhash; Cavatorta, Maria Pia
• Is Part Of: International journal of human factors modelling and simulation. Volume 7:Number 2(2019)
• Page Start: 119
• Page End: 136
• Publication Date: 2020-02-20
• Subjects: musculoskeletal model -- industrial exoskeleton -- virtual assessment -- human-exoskeleton interaction -- passive exoskeleton -- interface forces -- biomechanics -- exoskeleton effectiveness -- friction modelling -- lower limb exoskeleton; Human-computer interaction -- Periodicals; Human-machine systems -- Periodicals; 004.019
• Languages: English
• ISSNs: 1742-5549

Abstract

In virtual assessments of exoskeletons, often, friction is not modelled even though the actual interface consists of straps or moulded surfaces, where friction could play a significant role. In this work, the human-exoskeleton interaction during the use of a passive lower limb exoskeleton is modelled in three test cases through two different interface models. In particular, a model introducing friction at the human-exoskeleton interface is compared with a more conventional model that uses a kinematic joint to simulate the interface forces. Both the models show a good match between the empirical and predicted distribution of body weight between the subject and the exoskeleton. However, the results also show different trends of the moment required at the assisted joint by the different interface models, highlighting the importance of a realistic interface model to investigate the effectiveness of the exoskeleton in virtual assessments.