The Effect of Pre-Crash Seat Rotation with and without Feet Support in Highly Automated Vehicle Rear-End Crash

An automated driving system (ADS) shall provide safer conditions for highly automated vehicle (HAV) users compared to standard vehicles since human error is excluded. In the following decades, however, one can expect a mixed fleet of both standard and automated vehicles on roads. Therefore, collisions between manually driven cars and HAVs are to be expected. On the other hand, HAVs’ occupants access more room in the vehicle which allows them to rotate their seats to have a comfortable position. This work aims to address the issue of HAV’s occupant safety using tools of numerical simulations. We consider an FE model of a seat with the standard three-point belt at two initial orientations 45° and 90°. The occupant (50th percentile male) is represented with the Virthuman model. We test the idea of employing the active seat rotation system. By detecting a crash well in time an initially rotated seat is reoriented into a standard seating orientation in a rear-end crash. To improve the rotation system, we propose an additional element in a form of a feet support tool. The results are evaluated in terms of occupant’s kinematics and injury risk. They suggest that pre-crash seat rotation can postpone the injury occurrence time in most of the body parts which will provide sufficient time for other safety tools such as airbags.