Distance Corrected Capacitive Sensors for Advanced Air Bag Applications

The Federal Motor Vehicle Safety Standards No 208 now includes directives requiring the morphological estimation of passengers mandatory for Advanced Airbag systems. The Dynamic Automatic Suppression System, which is part of the advanced airbag system uses both morphological and positional information about the passenger to allow or prevent airbag deployment. Various solutions have been proposed to obtain this information by using for instance capacitive sensors. The response of this kind of sensors depends drastically on their distance from the passenger. This paper presents a method now implemented in the BIOVOLUME technology developed by Faurecia in partnership with Hitachi computer products to create the sensors independent from this distance.