Evaluation of Motion Comfort using Advanced Active Human Body Models and Efficient Simplified Models
Raj Desai (TU Delft - Intelligent Vehicles)
Marko M. Cvetkovic (TU Delft - Intelligent Vehicles)
G. Papaioannou (TU Delft - Intelligent Vehicles)
R Happee (TU Delft - Intelligent Vehicles)
More Info
expand_more
Other than for strictly personal use, it is not permitted to download, forward or distribute the text or part of it, without the consent of the author(s) and/or copyright holder(s), unless the work is under an open content license such as Creative Commons.
Abstract
Active muscles are crucial for maintaining postural stability when
seated in a moving vehicle. Advanced active 3D non-linear full body
models have been developed for impact and comfort simulation, including
large numbers of individual muscle elements, and detailed non-linear
models of the joint structures. While such models have an apparent
potential to provide insight into postural stabilization, they are
computationally demanding, making them less practical in particular for
driving comfort where long time periods are to be studied. In
vibrational comfort and in general biomechanical research, linearized
models are effectively used. This paper evaluates the effectiveness of
simplified 3D full-body human models to capture comfort provoked by
whole-body vibrations. An efficient seated human body model is developed
and validated using experimental data. We evaluate the required
complexity in terms of joints and degrees of freedom for the spine, and
explore how well linear spring-damper models can approximate reflexive
postural stabilization. Results indicate that linear stiffness and
damping models can well capture the human response. However, the results
are improved by adding proportional integral derivative (PID) and
head-in-space (HIS) controllers to maintain the defined initial body
posture. The integrator is shown to be essential to prevent drift from
the defined posture. The joint angular relative displacement is used as
the input reference to each PID controller. With this model, a faster
than real-time solution is obtained when used with a simple seat model.
The paper also discusses the advantages and disadvantages of various
models and provides insight into which models are more appropriate for
motion comfort analysis. For designers and researchers in the automotive
and seating industries, the findings given in this paper provide useful
insights that will help them improve the comfort and safety of both
vehicle occupants and seats.