Smart airbags to the rescue

The risk of serious injury in a car-crash is further reduced as new airbags adapt to the seat occupant.

To keep us even safer in our cars the newest airbags will adapt to the individual in the seat. Adaptive Restraint Technologies – which are known by the term ‘smart airbags’ – increase occupant protection by adapting to the size, position and weight of each occupant and to the crash profile.

Under development by Delphi, smart airbags tailor their characteristics to the type, weight, position and posture of each occupant, the crash severity and to whether seat belts are being worn.

The system is said to determine instantly whether the airbags should deploy and at what speed. For example, for small, lightweight occupants, the smart airbags inflate with less pressure and at a lower speed. this will help to prevent the injuries and fatalities reported to have been caused by inflating airbags to children.

Deceleration from a crash is sensed by a single point sensing system using micromachined accelerometers. These trigger the deployment of frontal airbags, pretensioners, and side airbags. The system is designed so restraints are not activated in low severity crashes or abuse events.

To detect side strikes, impact sensors are installed that trigger inflation in as little as 3ms. They are designed not to operate with normal jolts such as door slams.

The occupant position sensor determines if the seat is occupied by an adult, child, rear-facing child seat, or is empty. It also uses weight sensing, infrared and ultrasonic technologies to tailor its reaction. The adult-weight threshold sensors, located within the seat, will prevent an airbag from firing if the passenger’s seated weight is less than a preset level. Also incorporated in the system is a sensor to detect the presence of a rear-facing child seat.

As seats are adjusted forward or back, the position sensor located on the seat track enters those variables into the system.

At the front of the vehicle is a crash severity sensor. In a collision this unit will determine how severe the impact is and send a signal to the airbags.

There is even a rollover prediction sensor to advise the restraint system if the vehicle is about to roll. In addition there are anticipatory crash sensors located in the front and sides of the vehicle. The controller uses this information, along with the crash acceleration pulse, the deploy the restraints.

Delphi Automotive Systems. Tel: 01203 646106