STUDY OF REAL WORLD OCCUPANT POSTURES AND PASSENGER BRACING BEHAVIOUR

摘要

This paper reports the findings of studies from the "PRISM" project, intended to determine appropriate smart restraint technologies for Europe. The combination of the two studies aims to identify real world occupant postures at instant of impact. The first study was an occupant photographic study undertaken on a total of 5106 vehicles from 3 different European countries, (Spain, Austria and the UK). Posture measurements and observations were taken for each occupant sample. Information, such as seat belt usage (overall, 93% of drivers) and face-to-steering-wheel-gap (mean of 470mm for males and 430mm for females) was obtained. Additional data regarding hand and arm positions and other aspects were also recorded. The data was entered into a custom made database for further analysis. The second study was a volunteer passenger study undertaken on a vehicle proving ground in an instrumented test car. The "bracing" behaviour of 49 volunteers was filmed during "pre-impact" vehicle manoeuvres from initial postures observed in the first study. A maximum of 3 events per volunteer were undertaken to limit the effects of expectation of each sudden event. Whilst there was a large variation in reactions, some conclusions can be drawn. Leg bracing tends to dominate occupant kinematics and occupants tend to "freeze" arms and hands unless already holding some firm structure, or the pre-impact event is of long duration. Some "out of position" postures were shown to exhibit significant risk of injury from passenger airbag deployment and would benefit from the application of smart restraints. A simple comparison of the human volunteer occupants and a range of crash test dummies was also undertaken, showing that for longer duration pre-impact events, the correlation of dummies with humans is very poor. The methodologies for both studies are presented in the paper.