All About Airbags
How Airbags Work
When an accident occurs, airbags inflate faster than you can blink your eye. Airbags are key components in automotive safety systems, and, although we cannot see them perform under normal conditions with the naked eye, they soften the impact of collisions by keeping passengers from contacting the steering wheel, dashboard, front glass, and other parts of the automobile.
So, to explain what airbags actually do when an accident occurs, let’s use an example of a typical head-on collision.
*From this point forward, we will use the driver side airbag as our example and explain the way an airbag works. Figures are given as a reference.
How Airbags Work
After a vehicle collision has been detected, airbags inflate faster than you can blink your eye. Airbags are key components in automotive safety systems, and, although we can see them perform with the naked eye, they soften the impact of collisions by keeping passengers form contacting the steerling wheel, dashboard front glass, and other parts of the automobile. So, to explain what airbags actually do when an accident occurs, let´s use an example of a typical head-on collision.(*Frome this point forward, we will use the driver side airbag as our example and explain the way an airbag works. Figures are given as a reference.)
*T means the time of collision
second—Sensors detect the impact
As the satellite sensors (collision sensors) attached to the vehicle detects the collision, a signal is sent to the ECU (Electronic Control Unit).
second—Evaluation of the impact
The signal sent from the satellite sensors to the ECU is processed, and the ECU determines the severity of the impact based on inputted data. If the ECU determines that an airbag deployment is necessary, it sends a signal to initiate the airbag inflators (gas emitting devices).
second—The airbags go into action
The inflators are activated through an igniter, causing a chemical reaction that emits gas, resulting in the deployment of the airbag cushion.
second—Inflation of the airbags is completed
The force of the collision reaches the passengers, and they begin to move forward. By this time the airbags are fully inflated and they are ready to receive and restrict the movement of the passengers. The inflation of the driver side airbag takes between 20- 30 milliseconds. For the passenger side airbag, it takes between 30-40 milliseconds.
- Key Point!
- The time to inflation is measured in milliseconds. This is less than half the time it takes for us to blink an eye, which requires between 100 and 200 milliseconds.
second—Passenger motion energy is absorbed
By this time, the airbags are fully inflated. The motion energy of the passengers are absorbed by the crushing of the vehicle, the seat belt load limiter, and the airbags.
second—Passenger motion energy is fully absorbed
The energy of passenger movement is fully absorbed.
- Key Point!
- The proper name for airbags is “Supplemental Restraint Systems,” and as the name suggests, they play a supplementary function in protecting the passengers. Airbags can only be fully effective when they are used in combination with seat belts.