How can an airbag know when it should go up or not?


How can an airbag know when it should go up or not?

In: Technology

There’s a force sensor connected to the electronics that fire off the airbag.

If the force sensor detects a sharp enough shock it’ll set the airbag off.

There’ll be ones set at different angles and positions to know whether to set the front airbags off, or the side airbags. Or both, in fact.

Throughout the car there are different sensors measuring acceleration, deformation and forces. With this sensor data a computer can determine, if a crash happened or not and deploy different airbags. Usually this is done by training some kind of mathematical model with sensor data of countless simulations of crash (and non crash) scenarios. Obviously it is important that the airbag deploys during a crash to protect the driver. But it is also important that the airbag isn’t deployed in scenarios where it’s not necessary or could even be dangerous to the occupants.

The airbag uses a g-force sensor that measures sudden and huge deceleration. Much stronger decelerating than you can do through normal braking,
The airbag still inflates in a fraction of a second as the crash is happening

There are sensors positioned at multiple points in the car. These are connected to a computer which determines which airbags to deploy. What determines if they deploy at all is dependent on the energy of the collision. Low speed collisions under 15mph will probably not trigger the airbags. Side collisions will trigger the side curtain airbags (Some cars may deploy them in front collisions too). Rear end collisions will usually not deploy airbags. There’s also seat sensors, if there’s not a significant amount of weight on the seat, that sides airbags will not deploy. This is to help prevent injuries to children sitting in those seats. It can also save repair costs if you’re in an accident that is not severe enough to total the car; As airbag replacements are expensive.