TRW Automotive Safety Systems has unveiled its advanced asymmetrical airbag technology, incorporating a non-rotating driver airbag module with an airbag cushion specifically designed to fit the shape of individual vehicle interiors.

This next-generation steering wheel system, launched with an unspecified major European vehicle manufacturer (Citroen currently has non-rotating steering wheel centres in its C4 line and has just launched a new Picasso minivan version), increases the protection potential during different crash configurations, particularly for vehicles with extreme angled windshields and/or A-pillars in oblique crashes. This advanced system also enhances a vehicle's comfort and design.

Mehran Khazami, European engineering director for driver airbags and steering wheel systems, said: "New car designs and safety regulations have challenged vehicle manufacturers to rethink the shape of the driver's side airbag. A crash simulation, based on regulated industry tests, showed that TRW's asymmetrical airbag technology provides very impressive safety benefits."

In addition to the safety benefits, having a stationary steering module allows automotive designers to add more convenience and aesthetic features to the steering wheel system. The non-rotating driver airbag module can accommodate the use of multifunction switches that remain in the same location, even when the steering wheel is being turned. Additional design elements and parts of the instrument panel display can also be integrated into the steering wheel module.

In order to uncouple the rotation of the steering wheel from the driver airbag module TRW has developed a system with a circumferential gear to keep the airbag module in a stationary position.

The system utilises direct force transmission from the steering wheel spokes into the steering column. This improves steering feel by giving the driver less resistance when the wheel is turned. Both steering wheel and steering column will maintain the same centre and number of rotations; this eliminates the need to synchronise the number of rotations between wheel and steering column.