Probability of Frontal Airbag Deployment in Bumper-Bumper and Underride Collisions
To be published on April 2, 2019 by SAE International in United States
Airbag deployment thresholds can be a useful metric of collision severity in accident reconstruction applications. The National Automotive Sampling System (NASS) has provided a publicly-available database of real-world motor vehicle collisions, including more than 10,000 event data recorder (EDR) reports of data retrieved from airbag control modules. The majority of the EDR reports represent vehicles manufactured by GM, Toyota, and Ford. These reports typically indicate the airbag deployment status and the corresponding delta-V of each recorded event. Previous studies analyzing crash data in the NASS database have shown that the airbag deployment threshold may vary between vehicle manufacturers and over time. However, the statistical analysis was limited to Ford and GM vehicles due to insufficient data. This paper expands on the prior study of frontal airbag deployment threshold by analyzing newer years of NASS EDR data (4,000 additional crash reports). We performed statistical analysis to determine the effect of vehicle manufacturer (GM, Toyota, Ford), vehicle type (sedan, SUV, pickup truck) and model year (1994-2015) on airbag deployment criteria. Preliminary results indicate the delta-V for a 50% probability of deployment event is higher for Toyota vehicles (11 to 12 mph) than for GM and Ford vehicles (8 to 10 mph). Moreover, SUVs and pickup trucks had higher deployment thresholds than sedans. In addition, an increase in delta-V thresholds was observed for more recent vehicle model years. There was no observable distinction between the probability of deployment and deployment times for buckled and unbuckled drivers, consistent with findings of a prior study. This paper will also report the delta-V airbag deployment thresholds for underride collisions, which is expected to be higher than for collisions with bumper-bumper engagement.