A new airbag system uses sensors like those in roadside truck scales to assess the size of car passengers.
The system is the first product of a partnership between Siemens Automotive Corp. and Breed Technologies Inc.
The companies, whose joint venture is called BSRS Restraint Technologies, are contributing to the system components that they developed separately.
The system will sense a passenger's weight and position in the seat and use that information to vary the deployment force of the passenger-side front airbag.
Siemens, based in Auburn Hills, Mich., and Breed, based in Lake-land, Fla., are pushing the system as a way to meet proposed federal rules mandating the installation of so-called smart airbags starting in 2002.
Siemens will supply the electronics, including a control unit and four 'strain-gage sensors' embedded in the four corners of the seat. These miniature truck scales contain a wire grid bonded to each sensor that measures the electri-cal resistance change caused by weight.
The data are crunched by the controller, which classifies the seat as empty or occupied by a child, a small adult or a full-sized adult. It also determines where the occupant is in one of three zones.
The information is sent to the airbag module, made by Breed, which deploys the bag using a dual-stage inflator that has two available levels of force.
BSRS Technologies was formed early this year to market seat belt and airbag systems.