They’re concealed in the steering wheel, in the dashboard or in the seat, and drivers would like it to stay that way: for over 30 years, airbags have been ensuring the safety of vehicle passengers. Volkswagen equipped a Golf GTI with an airbag demonstrator to show what an airbag looks like inflated and how it works – without the accident. Festo developed the required compressed-air system that inflates the protective airbags at the press of a button.
Airbags usually fill with air at lightning speed on impact – within 20 to 50 milliseconds. In the test vehicle, the airbags inflate somewhat more slowly, within five seconds, so as not to unintentionally startle or injure the passenger during the demonstration. Several compressed-air reservoirs are required to complete the process and controlled via a valve manifold and a control module.
When you press the button, the head, front, side and knee airbags fill with 120 litres of air, allowing the person in the driver’s seat to experience their protective effects. The system then suctions the air out of the airbags, which are subsequently replaced with new ones. A compressor fills the compressed-air reservoirs and the demonstrator is ready for the next time.
Development of a complete system
Festo engineers developed a complete system that also comprises a switch cabinet, control software and a visualisation display. All the equipment, including the vacuum pump and the compressor for filling the compressed-air reservoirs, is contained in the boot of the Golf. An emergency off switch, which can immediately stop the demonstration, and a variety of sensors that monitor system operation and the person ensure the safety of the ‘driver’.
This unique vehicle was presented for the first time at Volkswagen’s open day in June. It also made an appearance at the IdeenExpo in Hanover, a trade fair for young people interested in technology and science.