iBolt Technology — A Weight Sensing System for Advanced Passenger Safety

In 2004 the NHTSA FMVSS-208 ruling became effective, to avoid injuries of children by unwanted deployment of the passenger airbag. To fulfil the requirements of this law, several technical principles are under development or had a first product launch recently. The key technologies are weight sensing by measuring strain or displacement or mat solutions either fluid filled or as pattern recognition. This paper presents the Bosch iBolt technology, a direct weight measuring system, which is an integrated and therefore functional part of a seat. The advantages and properties of this technology will be described depending on the main questions, like insensitivity against lateral forces and moments, temperature behaviour and packaging issues both on component and seat level. The weight sensing iBolts are installed directly into the seat frame, replacing existing bolts, so no H-point shift is caused by integrating the iBolts sensors.