Volunteer occupant kinematics during driver initiated and autonomous braking when driving in real traffic environments

When a vehicle is braking, the occupants are subjected to longitudinal forces which may influence their positions. The aim of this paper is to quantify the driver and passenger kinematics during medium harsh braking while driving in real traffic and to identify the influencing parameters. The overall motions were relatively small during braking and the effect of seat belt locking was obvious. Mean forward motions were 55 ±26 mm for the chest and 97 ±47 mm for the head. This study indicates that several properties influence forward motion. Taller volunteers had a larger forward motion; females had a larger forward motion than males of the same sitting height. Passengers exhibited larger motions than drivers for most of the volunteers. The result provides a deeper understanding of pre-impact conditions and adds knowledge to further improve the interaction of active and passive safety systems. It also provides valuable validation data for low-g occupant models, which can be used in studies of the effect of pre-impact braking on restraint interaction