New algorithm and accelerometer locations for frontal crash discrimination

Abstract

Several crash discrimination algorithms have been developed in order to have timely air bag deployment during frontal crashes. However, it is still challenging to have timely air bag deployment, especially during pole, underride, oblique and offset crashes. Therefore, in this paper, a new algorithm for frontal crash discrimination is proposed, with the summation of the absolute value of the deceleration change being used as a metric and with the metric and its threshold being processed as a function of the velocity change. The new algorithm was applied to frontal crashes of a minivan and a sports utility vehicle, and it resulted in timely air bag deployment for frontal crashes, including pole, underride, oblique and offset crashes. Moreover, it is proposed that an accelerometer be installed on each side of the rockers or pillars to assess the crash severity of each side and to deploy driver and passenger air bags at different times, especially during an asymmetric crash such as an oblique and an offset crash. As an example, the deceleration signals measured at the left and right B-pillar/rocker locations were processed through the algorithm, and earlier time-to-fires (TTFs) were obtained for the air bag on the struck side than for the air bag on the non-struck side.