A method to model anticipatory postural control in driver braking events.

Area of Science:

• Biomechanics
• Human Body Models
• Vehicle Safety

Background:

• Human body models (HBMs) simulate vehicle occupants, incorporating active muscles and postural control.
• Previous models focused on autonomous braking; driver-initiated braking responses differ significantly.
• Understanding driver anticipatory responses is crucial for accurate vehicle safety simulations.

Purpose of the Study:

• To hypothesize, model, and validate an anticipatory postural response in a whole-body HBM for driver-initiated braking.
• To investigate differences in occupant kinematics between driver and autonomous braking scenarios.
• To apply the developed modeling method to other driver voluntary actions.

Main Methods:

• Developed a whole-body HBM with feedback-controlled muscles.
• Modeled anticipatory postural response as a time-dependent change in feedback controller reference values.
• Validated the model using existing volunteer data from maximum braking tests.

Main Results:

• Simulations with anticipatory postural response reduced peak head forward displacement by 100mm and shoulder displacement by 30mm during 11 m/s² braking.
• Peak head flexion rotation was reduced by 18° with the inclusion of anticipatory responses.
• The HBM's kinematic response closely matched volunteer test data, falling within a one standard deviation corridor.

Conclusions:

• Anticipatory postural responses in driver-initiated braking can be effectively modeled by adjusting joint feedback controller reference positions.
• Incorporating these anticipatory muscle activations helps explain kinematic differences between driver and autonomous braking.
• The modeling approach is applicable to simulating other driver voluntary actions, like emergency steering maneuvers.