Airbag systems are one of the most vital vehicle components for safety. When properly deployed, they ensure passengers survive an otherwise fatal or perilous crash. Airbags have saved thousands of lives but only a fraction of those people understand how they work. For starters, airbag systems are complex mechanisms designed to activate within milliseconds of a catastrophic impact.
What is an airbag?
An airbag is stretchy material that is tightly packet into various spots within a vehicle. Most cars have them in the dashboard and side-mounted components are not unheard of. These bags are compressed to fit within a small area, quickly surging forward and growing to cushion against impact and reduce how far a body will travel due to impacting forces. While they cannot stop total injury or death, airbags are still extremely helpful.
Crash sensors
The crash sensor is the most crucial component of an airbag. These small electronics detect when a vehicle has been damaged and respond in several ways, including locking the brakes and raising pressure to reduce a collision.
Different sensors measure wheel speed, occupancy, brake pressure and impact through the airbag control unit placed within the front cabin. Sensors relay data to this unit and the unit analyzes the data to control seat belts, automatic doors and when to deploy airbags. There are two main varieties of automotive airbag sensor.
Electrical
These vary in design, with some using a ball-and-tube mechanism that involves a small tube filled with a circuit and ball kept in place with magnetism. A collision dislodges this ball from the magnet, sending the tube rolling into the switch and completing a circuit. Other designs works similarly but use things like metal rollers, spring-weights (instead of a ball) or even acellerometers.
Mechanical
These work independent of the electronics while working similarly to them, designed with a firing pin that triggers an explosion in response to a crash. Since mechanical sensors function without electricity, they cannot be deactivated when the battery is removed like with electrical sensors.
A successful airbag system needs functional crash sensors to work properly. This is why the most costly and futuristic components of airbag systems are their sensors.
Inflator
Once the control unit senses an accident, it initiates inflation. This system deploys an explosion of nitrogen gas to fill the bag, send it bursting through paneling to fill space at approximately 200 miles per hour and protecting those inside.
