Airbag energy storage device failure

Why do airbags have energy reserve capacitors?

The energy reserve capacitors used in the ACU (Airbag Control Unit) are provided so that once a crash event occurs and Loss of Battery (LOB) occurs in turn, the airbags can still be powered with their help as an emergency supply system.

Are airbag control units safe in case of a crash?

Airbag control units are safe in case of a crash Electronics are providing functional safety -> ASIL D Mandatory data has to be stored even when the battery is cut off (autarky) Storage is not continuous but in discrete sections which increases storage time. The sections can only be recorded sequentially (see below)* *Diagram not to scale.

What happens when an airbag battery is lost?

When battery is lost, the Airbag ECU draws current (I) from the capacitor (C). When the voltage across the capacitor falls below a threshold, writing of EDR stops. CLEPA recommends limiting the amount of additional data to <20% of what is recorded today.

How long should a side airbag be deflated after a crash?

The airbag should be deflated in 1–1.5 s after the crash to ensure the free movement of the driver or passenger after the collision . By contrast, the purpose of the side airbag is not to absorb the energy of the collision, but to isolate the passenger from the location of the crash.

How airbag system is activated?

Based on the seriousness of the impact, the airbag system may be activated. Than an inflation module initiates gas generation by initiators (with its thermal resistance) , which fills the airbag cushion itself . Under normal operating conditions, initially all of them are take place inside the housing.

Why are airbags important in a car?

Airbags are representative safety devices in passenger cars which can absorb the energy of crashing and preventing personal injuries during accidents.