The seat belt is a passive safety element that, by law, all vehicles must be equipped with. Its origin dates back to the late 1950s when an engineer working for Volvo introduced this retention system. Its effectiveness is beyond doubt, since according to estimates by the European Transport Safety Council (ETSC), it would have saved more than a million lives during the first 50 years after its implementation worldwide.
The seat belt was not mandatory in Spain until 1975, although only for the front seats. Since 1992 it has also been mandatory for rear seat passengers. At first, this item consisted of a simple cloth band that fit around the body, and its acceptance among drivers was limited. Over time, the mechanism was sophisticated to include more advanced retention systems, quick-release buckles, and automatic tensioners that adjust in the event of a collision.
After a long time without significant advances, the German firm ZF, one of the market leaders in the production of automatic gearboxes, has given a twist to the seat belt. If at the beginning of this year it presented a heated belt to increase the comfort of the driver and passengers, now its engineers have developed and patented an active belt that increases the protection of occupants in the event of an accident.
The belt is called ACR8 and is integrated into the assistance systems that equip the most modern cars. In this way, if the car's sensors detect a dangerous driving situation that could cause sudden braking or a collision, the seat belt system acts immediately to improve passenger protection. When connected to the automatic emergency braking assist, the belt moves the occupant to the correct position and keeps them there during the braking maneuver.
In the event of a subsequent collision, pyrotechnic adjustment is initiated and the functionality of the airbag and seat belt restraint system is improved.
Although initially it may seem that the ACR8 belt works in the same way as a conventional belt, that is, activating the pretensioner in the event of a collision or sudden braking, the truth is that it acts in a more sophisticated way, anticipating danger. A small electric motor is responsible for maintaining the specific force necessary to hold the body in an upright position and minimize the risk of injury in the event of an accident.
The belt developed by ZF engineers guarantees the correct position of the occupant in the seat at all times, minimizing impacts during sudden braking, whether caused by collisions or unexpected traffic situations, such as the activation of emergency braking. .
The system is specifically designed to activate only in cases of imminent danger. Therefore, the safety sensor will not be activated if, for example, the person sitting next to the driver makes a forward movement to open the glove box. It will only do so only in genuinely critical situations that require an immediate response.
The connected belt also has a specific function on the driver. When the vehicle's safety systems detect symptoms of fatigue, they notify the driver haptically, through vibrations, alerting them of this dangerous situation. The same thing happens when switching from automatic to manual driving mode.
