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Occupant Trajectory Model using Case-Specific Accident Reconstruction Data for Vehicle Position, Roll, and Yaw
Abstract:
In the fields of accident reconstruction and injury biomechanics, it is often of interest to know details of an occupant's ejection from a vehicle during a rollover. Current occupant trajectory models do not account for vehicle yaw and yaw rate. Such considerations are compulsory if the occupant's rest point has a non-trivial deviation from the vehicle's roll path. Moreover, many existing models use a single, generic function for the roll rate for all analyses. Such approaches intrinsically model all rollovers as identical events, regardless of the underlying uniqueness a particular accident may exhibit.
The objective of this work is to model the trajectory of an occupant ejected from a vehicle in a rollover event. In particular, we model the vehicle's longitude, latitude, roll, yaw, and time derivatives thereof, based on data extracted from a particular accident reconstruction. We model the occupant moving in the vehicle and possibly ejected at any time during the rollover. For each admissible ejection time, we construct an occupant trajectory, landing point, and point of rest (POR). We illustrate the effectiveness of our model with a case-study where significant yaw occurs during the rollover.
Our new model, when compared with existing approaches, provides an improved understanding of occupant ejection. Additionally, the new model eliminates spurious ejection solutions predicted by previous formulations. Finally, the new model is tailored to the underlying accident reconstruction data, producing a simulation that is based on the uniqueness of a particular rollover event.