Airbags get smarter

A collaborative EU project between car makers, component suppliers and the Fraunhofer Institute for Chemical Technology ICT has led to the development of a new ‘smart’ airbag system.

A collaborative EU project between car makers, component suppliers and the Fraunhofer Institute for Chemical Technology ICT has led to the development of a new smart airbag system.

By 2002, all new cars in Europe will be equipped as standard with driver and passenger airbags, with side airbags becoming standard in 2005.

One of the key components of an airbag is the gas generator and Fraunhofer researchers have developed a new type of generator for this smart system, consisting of a casing, an ignition element and a solid fuel in tablet form.

‘In a crash, the tablets can be converted into as much as 100 litres of gas within 40 milliseconds’, said Dr Norbert Eisenreich of the ICT. ‘A force greater than the fist of a professional boxer is behind every deployment. To prevent the driver from receiving the full force of the inflating airbag, sensors detect the driver’s exact position and induce a time-delay to create the appropriate flow of gas accordingly.’

The technical design of the generator casing is said to enable the time-delay function. ‘We performed a detailed analysis of its properties to determine precisely how the propellant behaves during combustion.’

The chemical composition in the tablet enabled the researchers to meet several requirements at once. They found that the gas generator performs effectively, is cost-efficient and environmentally friendly.

Additionally, in comparison to current airbags, the gas is said to be generated at a relatively low combustion temperature. At the same time, the generator is safe and resistant against external influences.

The Fraunhofer researchers also designed a special casing for the generator. Since the new generator reacts at a lower pressure in comparison to current technology, its casing has a lower mechanical stress to withstand, leading to a reduction in production costs.