Bags more safety

Bosch has developed a system that uses sensors mounted beneath car seats to adjust airbag deployment to suit the different sizes and seating positions of the occupants.

The German technology firm’s iBolt system uses sensors built into the four bolts that anchor a car seat to the chassis. While a number of car companies have experimented with intelligent air bags, building the sensors into the seat bolts makes it cheaper and much easier to integrate within existing car designs than the more complicated systems developed elsewhere, according to company spokesman Richard Backhaus.

‘The sensors are built into the bolts and these bolts are already on the seats so it’s easy for an automotive manufacturer to switch to the iBolt system,’ he said.

The sensors in the seat chassis measure the weight of the passenger. But as they are attached to all four corners of the seat the information they provide can also be used to calculate the weight distribution and therefore their seating position.

A control unit built into the seat evaluates readings provided by the sensors and determines the optimum way to deploy the air bag. This information is then sent to the central air bag control electronics.

Backhaus explained that the system was developed largely with Federal Motor Vehicle Safety Standard 208 in mind.

This piece of US legislation requires that, to improve safety, air bag release is matched precisely to a passenger’s weight. ‘iBolt decides whether to open, not to open or partially to open the air bag,’ explained Backhaus. The system can differentiate between a full release for larger heavy people, a restricted release for smaller people and children, and no release at all for infants, who can be injured by air bags.

The technology will make its debut in 2006 on US passenger vehicles, although Backhaus declined to reveal the name of the car manufacturer concerned. He added that Bosch is also discussing the use of the system with European manufacturers but that the US represents the biggest potential market.

This is largely because of the relatively lax seat belt laws in the US. According to that country’s road safety pressure group, the Automotive Coalition for Traffic Safety (ACTS), only 21 states have safety belt laws that allow police officers to issue tickets to drivers for not wearing a safety belt. The remaining states have laws that allow officers to book drivers for not wearing a belt only after they have already been cautioned for another violation.

It is estimated that around 20 per cent of Americans do not use their seat belts. Backhaus explained that because of the laxer laws US car makers expect American drivers to be far more reliant on their air bags than European drivers.

On the web