This paper defines realistic achievable 30 mph (48 kph) vehicle to frontal barrier crash pulses (in the Delta-V domain) for optimum single-point occupant compartment sensing, and total airbag performance. These optimum Delta-V pulse shapes are established through airbag system computer modelling, but are based on examination of many vehicle to barrier crash pulses to insure realistic achievability. Not only do "optimum" airbag crash pulses need to be defined, but also "upper and lower bounds" within which good performance can be achieved. Through computer modelling, upper and lower bounds are established that: (1) provide acceptable compartment sensing times (including allowance for sensor manufacturing tolerance bounds); and (2) should limit airbag injury measures to 350 Head Injury Criterion (HIC) and 40 Chest G. Although established for a 30 mph frontal barrier crash, knowledge and experience have been used in defining the Delta-V pulse shapes such that good sensor performance would also be expected in the mid speed range. In accordance with this objective, undesirable Deltva-V pulse shapes that are within or near that optimum pulse boundary are also shown. (A)
Abstract