How Does Car's Airbag System Work?

The airbag system is one of the most important parts of your vehicle's safety components. Proper airbag deployment can ensure that you and your passengers survive a crash where you may have otherwise experienced serious injury or death.

 Air bags were introduced in passenger cars in early 1980s and their deployment has saved thousands of lives through the years. But how exactly do they work?
The airbag system is extremely complex and needs to activate within milliseconds after a crash occurs to ensure the protection of the driver and passengers from the forces of a head-on collision.

What Are Airbags?

Airbags are stretchable fabrics or other materials that are tightly packed in various locations throughout your vehicle. There are airbags at the front of the dashboard in most cars, and many vehicles have airbags along the side of the car as well. These bags are compressed and kept in a small area. When there is an accident, the airbags fill up with air very quickly to provide a cushioning system for the people in the car so that they are not thrown around in the event of a crash. While this does not necessarily prevent total injury or death, it can be very helpful in cushioning the passengers in a car in many cases.

There are three main parts to an air bag.

 First, There is the bag itself, which is made of thin, nylon fabric and folded into the steering wheel or the dash board.

2.  Crash sensor -The most important part behind the success of the airbag system are the crash sensors. These small pieces of electronics are designed to tell when the vehicle has been damaged in an accident. They respond to several different sets of stimuli, including sudden stopping, increased pressure as pieces of the car are moved due to the force of the collision. It detects a collision force equal to running into a brick wall at 10 to 15 miles per hour (16 to 24 kph).Combination of accelaration sensors and pressure sensors are often used to detect sudden changes in pressure and acceleration experienced in the car.

3. Inflation system -  Air bags are actually inflated by the equivalent of a solid rocket booster. Sodium aside (NaN3) and potassium nitrate (KNO3) react very quickly to produce a large pulse of hot nitrogen gas. This gas inflates the bag, which literally bursts out of the steering wheel or dashboard as it expands. About a second later, the bag is already deflating (it has holes in it) in order to get out of your way and to prevent choking hazards.

The typical view of this process is shown in fig :-