An airbag is an essential element of a vehicle's passive safety system. This is a bag of strong, flexible fabric that is inflated with gas in an emergency to absorb the impact of a collision. The '87 Porsche 944 was the first model with a standard front airbag. Today almost all modern vehicles are equipped with them.
How airbags work
Sensors in the bumper, interior and doors record the time and force of the impact. A corresponding signal is sent to the electronic control unit, where an electrical impulse triggers the propellant gas. He ignites the gas generator, which consists of potassium nitrate and sodium azide. As a result, a reaction occurs in which nitrogen is released, so that the airbag inflates in 0.3 seconds. The airbag will only deploy if the vehicle speed is 20 km/h or more at the time of impact. This reduces the risk of injury in minor traffic accidents.
It is possible to set the control unit with different activation algorithms for the airbag. The speed and deceleration of the vehicle as well as the position and body weight of the occupant are taken into account. For example, the system can be prevented from switching on if the seat belt is not fastened. It is also possible to switch off the system if there is a child seat on the front passenger seat.
Different airbag types
- Front: These are located in the center of the steering wheel for the driver and in the dashboard for the front passenger.
- Sides: These airbags are located in the backrests of the front seats. They protect the chest, stomach and pelvis from frontal and side impacts.
- Curtain: They are located in the roof or between the central pillars of the interior. This prevents head injuries.
- Central: Said airbags are located here between the driver and front passenger.
- Knees: These are located under the steering wheel and glove compartment. They are typically only found on luxury cars.
- Pedestrian Protection: Located on the front of the vehicle body, these minimize injuries in the event of a collision with a pedestrian.