Behavior of Toyota Airbag Control Modules Exposed to Low and Mid-Severity Collision Pulses

The repeatability and accuracy of front and rear speed changes reported by Toyota’s Airbag Control Modules (ACMs) have been previously characterized for low-severity collisions simulated on a linear sled. The goals of the present study are (i) to determine the accuracy and repeatability of Toyota ACMs in mid-severity crashes, and (ii) to validate the assumption that ACMs function similarly for idealized sled pulses and full-scale vehicle-to-barrier and vehicle-to-vehicle crashes. We exposed three Toyota Corollas to a series of full-scale aligned frontal and rear-end crash tests with speed changes (ΔV) of 4 to 12 km/h. We then characterized the response of another 16 isolated Toyota ACMs from three vehicle models (Corolla, Prius and Camry) and 3 generations (Gen 1, 2 and 3) using idealized sled pulses and replicated vehicle-to-vehicle and vehicle-to-barrier pulses in both frontal and rear-end crashes (ΔV = 9 to 17 km/h). The ACM-reported speed changes were compared to reference speed changes calculated by integrating an accelerometer signal. The pooled data for reference speed change were then linearly regressed against the following predictors: ACM-reported speed change, peak acceleration, vehicle type, collision type and ACM generation. We found that all of the independent variables had a significant effect in at least one of the models we considered, although ACM-reported speed change and ACM generation had the largest effects on the outcome. We found significant differences between the full-scale collisions and the sled pulses for frontal impacts, but these differences were small (<0.2 km/h) compared to the other variables. This study furthers our understanding of how Toyota ACMs behave in low and mid-severity collisions.