Modeling of Occupant Kinematic Response in Pre-crash Maneuvers A simplified human 3D-model for simulation of occupant kinematics in maneuvers - A simplified human 3D-model for simulation of occupant kinematics in maneuvers

Most car manufacturers today equip their cars with collision avoidance systems which can\nact to avoid or mitigate a crash. Retrospective studies have shown that these systems\nhelp reduce the number of crashes, however the intervening evasive maneuvers provoke\noccupant displacements. Consequently the occupant’s position relative to the restraint\nsystems of the car is affected. Therefore, there is a need to investigate occupant safety\nalso for the pre-crash phase when these evasive maneuvers take place. There are an\nextensive number of maneuvers to consider and the existing methods for simulating the\noccupant during the pre-crash phase are inefficient with respect to time. For that reason,\na more efficient dynamic model of the occupant was developed to primarily compute the\nhead kinematics and secondarily T1 kinematics, when the occupant model is subjected\nto the linear- and rotational accelerations that are induced by evasive maneuvers. The\nmodel represents the upper body of an occupant, i.e. a front seat passenger or a driver,\nwhich is restrained by the seat, the seat belt, as well as the arms if the model is a driver.\nTwo types of occupant models were proposed based on the inverted spherical pendulum\ntheory. The systems of differential equations were derived using Lagrangian mechanics\nand implemented in Simulink. The models were tuned and validated based on pre-existing\nvolunteer data from vehicle maneuver studies. The results demonstrate that the models\nwere able to capture the occupant kinematics by showing similar dynamic behavior to the\nkinematics of test subjects in volunteer tests. The computation time when simulating a\nmaneuver of approximately 4 seconds, resulted in a computation time of 0.7 seconds for\nboth models, which allows for efficient computation of an extensive number of pre-crash\nmaneuver simulations for analysis of occupant kinematics.