A Novel Approach to Simulating Realistic Exoskeleton Behavior in Response to Human Motion

Abstract

Simulation models are a valuable tool for exoskeleton development, especially for system optimization and evaluation. It allows an assessment of the performance and effectiveness of exoskeletons even at an early stage of their development without physical realization. Due to the closed physical interaction between the exoskeleton and the user, accurate modeling of the human–exoskeleton interaction in defined scenarios is essential for exoskeleton simulations. This paper presents a novel approach to simulate exoskeleton motion in response to human motion and the interaction forces at the physical interfaces between the human and the exoskeleton. Our approach uses a multibody model of a shoulder exoskeleton in MATLAB R2021b and imports human motion via virtual markers from a digital human model to simulate human–exoskeleton interaction. To validate the human-motion-based approach, simulated exoskeleton motion and interaction forces are compared with experimental data from a previous lab study. The results demonstrate the feasibility of our approach to simulate human–exoskeleton interaction based on human motion. In addition, the approach is used to optimize the support profile of an exoskeleton, indicating its potential to assist exoskeleton development prior to physical prototyping.

A Co-Simulation Model Integrating a Musculoskeletal Human Model with Exoskeleton and Power Tool Model

“…To simulate the dynamics of human-exoskeleton interaction, an exoskeleton model [37] is built in MATLAB Simscape (R2021b) firstly based on the CAD model of the shoulder exoskeleton Lucy [1]. The exoskeleton Lucy primarily supports the user in working at head level or above (Figure 2).…”

“…To mirror the kinematical adjustments of the exoskeleton, the positions of the armrests, shoulder bars and lap belt (white straight arrows in Figure 2) are parameterized in the model according to anthropometry. [37]. A multibody model is created for the integration of the exoskeleton into the co-simulation model.…”