| Airbag Control UnitThe airbag control unit detects and evaluates a crash, before triggering the appropriate restraint systems according to the type of collision and its severity. Information is supplied to the control unit by as many as six satellite acceleration sensors (crash sensors). The airbag control unit is equipped with acceleration sensors for the vehicle's longitudinal, lateral and vertical axes. It also incorporates a rotational speed sensor which monitors the rotation of the vehicle around its longitudinal axis. The readings from the control unit's own sensors are used to evaluate and compare the signals from the other sensors. This then enables the control unit to determine the direction of the impact and its severity, on the basis of which it can trigger the appropriate restraint systems. The crash signal outputs connect the airbag control unit to additional CAN data bus systems that expedite the task of locating and rescuing the occupants following an accident. The extensive research and ongoing development carried out at Volkswagen have refined control of the restraint systems to such a point that the protective effect can be optimised across the full spectrum of crash types. Front airbags with two-stage deployment controlled by the severity of the impact further reduce the risk of injury for the driver and front passenger. The system is able to differentiate between a crash, whatever its severity, and severe shocks to the vehicle caused by hitting a stone or a deep pothole, for example. This eliminates the possibility of a restraint system being deployed without a crash even occurring. |
