Active Muscle Responses in a Finite Element Human Body Model
Licentiate thesis, 2010
The development of automotive safety systems is moving towards an integration of systems that
are active before and during an impact. Consequently, there is a need to make a combined
analysis of both the pre-crash and the in-crash phases, which leads to new requirements for
Human Body Models (HBMs) that today are used for crash simulations. In the pre-crash phase
the extended duration makes the active muscle response a factor that must be taken into account
in the HBM to correctly simulate the human kinematics.
In this thesis, the active muscle response is modeled using a feedback control strategy with Hilltype
line muscle elements implemented in a Finite Element (FE) HBM. A musculoskeletal
modeling and feedback control method was developed and evaluated, with simulations of the
human response to low level impact loading of the arm in flexion-extension motion. Then, the
method was implemented to control trunk and neck musculature in an FE HBM, to simulate the
occupant response to autonomous braking. Results show that the method is successful in
capturing active human responses and that a variety of responses in volunteer tests can be
captured by changing of control parameters.
The proposed method, to model active muscle responses in an FE HBM using feedback control,
makes it possible to conduct a pre-crash simulation in order to determine the initial conditions for
an in-crash simulation with an FE HBM. It also has a large potential to extend the use of FE
HBMs to the simulation of combined pre-crash and in-crash scenarios, crash scenarios of longer
duration such as roll-over accidents and, eventually, multiple events.
human body model