The impact of body and head dynamics on motion comfort assessment

TL;DR

This study investigates how different human body models influence the assessment of motion comfort and sickness by simulating head and seat dynamics during driving, highlighting the importance of model fidelity.

Contribution

It compares advanced and efficient human body models in predicting head motion and comfort, revealing significant impacts on predicted ride comfort and sickness levels.

Findings

Human models significantly affect predicted ride comfort (up to 3x difference).

Model fidelity influences sickness predictions, especially with the SVC model (up to 70%).

Simulations show modest effects on sickness using existing filters and standards.

Abstract

Head motion is a key determinant of motion comfort and differs substantially from seat motion due to seat and body compliance and dynamic postural stabilization. This paper compares different human body model fidelities to transmit seat accelerations to the head for the assessment of motion comfort through simulations. Six-degree of freedom dynamics were analyzed using frequency response functions derived from an advanced human model (AHM), a computationally efficient human model (EHM) and experimental studies. Simulations of dynamic driving show that human models strongly affected the predicted ride comfort (increased up to a factor 3). Furthermore, they modestly affected sickness using the available filters from the literature and ISO-2631 (increased up to 30%), but more strongly affected sickness predicted by the subjective vertical conflict (SVC) model (increased up to 70%).