Airbag, A Basic Security Element

We are going to talk about one of the safety measures that street cars incorporate today, how important it is and how little we really know about them, we are going to talk about the Airbag.

Origins of the Airbag

The Airbag has been with us since 1981. The first to use them was the Mercedes-Benz brand, it began to be incorporated into the Mercedes S-Class.

Little by little over the years it has become an essential security system for us. To the point of finding it installed on motorcycles or biker jackets.

Mercedes took 10 years to develop the system.  This large margin of time is understandable after seeing the complex system that lies behind the mechanism.

Later,  in 1993 Ford began to include the system in all its cars. Some brands called it SRS, since its translation from English means complementary safety system to the belt.

An ally on the road

We cannot forget that the Airbag by itself in slow crashes is of little use and practically nothing in strong collisions, but if we combine it with the seat belt it saves many lives.

The Airbag serves mainly four things:

• To absorb part of the kinetic energy of the body , thanks to this it gently slows down their movement.
• Avoid impact against the elements inside the car.
• Reduce the risk of injury from glass shards
• Decrease head movement and thus reduce the risk of neck injuries.

Different varieties

The most important part of the Airbag, so to speak, is the brain of the system called UCE (Airbag Control Union), this is in charge of determining whether the activation of the Airbag is necessary or not.

It is firmly anchored to the car in the safest possible location. In the car we can find front airbags, which are hidden in the steering wheel, in front of the driver, on the dashboard … side, we have them hidden on the side of the seats or even inside the doors. We can also find them on the ceiling or curtain, they are placed on the ceiling and above the windows.

Each manufacturer has its own ECU, which will be different from its competitors in the market. But in general, it will  determine if the deceleration that has occurred is sufficient for the Airbag to appear on the scene, how much air should be introduced taking into account the weight of the occupant, at what speed the bag should be inflated, etc.

How does it work?

The UCE is made up of several pieces, among them we must highlight the sensor, but we must not forget the microprocessor, the capacitors and the EPRO.

Even as we have already said, the most important part is the impact sensor. This measures the decelerations of the car registered during the impact. Its main function is to take them in thousands of seconds to the microprocessor, which, taking into account all the parameters of the situation, decides whether to activate the aribag or not.

By having capacitors we are talking about a system that works independently of the electrical system of the car, so it can continue to work even in the event that the battery is deactivated as a result of the impact. The Epro performs a history of the system and provides the mechanic with the necessary information and a history of incidents.

If the decelaration is sufficient for the microprocessor to decide that the appearance of the airbag is necessary, it takes between 15 and 30 milliseconds to make an appearance . After this period of time, a detonation takes place that releases the gas necessary to inflate the air bag.

The airbag takes between 60 and 80 thousandths of a second to inflate  for the driver. If we talk about the co-pilot, the time margin will be greater since the passenger bag has more air volume. After the accident, the bag is deflating little by little.

As we have seen, the car is full of airbags with which it is intended to protect the driver and his occupants. However, let us remember that the most important safety element of the car is passive safety, that is, the seat belt. Let’s not forget that by putting both systems together we save many lives.