Head-on collisions can be dangerous. This even holds true for collisions on the opposite side to the occupant, as the impact can throw the occupant’s body toward the middle of the vehicle. A new airbag from ZF could help prevent injury here.
June 04, 2019
Martin Westerhoff studied technology journalism and writes about vehicles and technologies since then. He has a soft spot for motorsports and racing cars.
Modern cars now feature high-level safety measures deployable in the event of an accident. This is because the new vehicle models in many countries now come equipped with driver and passenger airbags as well as side and curtain airbags as standard. The latest results from crash tests demonstrate that occupants involved in a collision on the side of the vehicle opposite to the passenger, referred to as the far side in professional circles, can still be vulnerable.
In certain crash events, the test dummies show that the occupant’s torso could bend over the center console while the seat belt hold the pelvis back in the seat. As a result, the thoracic spine twists and the cervical spine can be overstretched. The dummy data readings indicate that serious injuries could result.
Airbag Concept for the Vehicle Interior
“Far-side safety countermeasures present an untapped area for injury reduction,” summed up the renowned accident investigator Dr. Kennerly Digges at a congress held by the US National Highway Traffic Safety Administration in 2015. Working together with nine additional partners from the fields of science and industry, Digges – a professor at the George Washington University in Ashburn, has carried out a great deal of research on this topic. He was also the initiator of the New Car Assessment Program (NCAP), which grades vehicles by means of crash tests, a star rating and is now the benchmark for vehicle safety in many countries. Likewise in 2015, ZF showcased its far-side airbag concept for the first time. Installed in the inward-facing side of the driver’s seat, the airbag can help to provide better protection to both the driver and front-seat passenger.
New Euro NCAP Test Requirements
The Euro NCAP, the European consumer protection organization for vehicle safety, has now become the first organization in the world to react to the far-side problem. The new test requirements that will be introduced in 2020 will expand the scope of the investigations into head-on collisions on the side of the vehicle opposite to the occupants. A total of 16 points within the Euro NCAP are awarded to head-on collisions; in future, 4 of these points will focus solely on the topic of far-side collisions. A car can achieve a maximum of 38 points in all four categories for the protection of adult occupants. The findings of an American-Australian joint research project have shown that this change is worthwhile. An analysis of accident statistics in both countries revealed that no less than 33 percent of all serious injuries or deaths suffered in head-on collisions were the result of far-side collisions.
A far-side crash is a collision on the side of the vehicle opposite to the occupant.
US Accident Data Shows the Need for Further Action
Recent evaluations of the national accident data, collected by the US National Highway Traffic Safety Administration from 2004 to 2013, present a detailed picture of the serious injuries that an be caused by far-side collisions: 43 percent of the injuries suffered were to the chest and abdomen and 23 percent were head injuries. Around 53 percent of the chest injuries were caused by contact with the center console or the backrest, while 21 percent were caused by the occupant colliding with external structural elements, such as the metal parts of the door. These statistics show that there is an opportunity to further limit the movement of both the head and the torso of occupants toward the middle of the vehicle in order to better minimize the risk of injury.
Good Support thanks to Two Chambers
The design of the ZF far-side airbag therefore focuses on two chambers that are arranged in a specific way to complement each other. “This special design was developed based on the fact that we want to support the head in the upper area as early as possible. The shoulders of the occupant are usually held in place between the two chambers. The entire upper body is therefore better supported on both sides,” explains Dominique Acker, an engineer involved in the preliminary development of side airbags in the Passive Safety Systems Division. This means that the airbag differs from the front and side airbags: the function of these airbags is to help reduce the body’s momentum by “enveloping” the occupant, while the far-side airbag provides the occupant’s body with more support. “The pressure in the chambers is therefore higher than in most other airbags,” explains Acker.
“We will commence with the first series production of our far-side airbag in a compact-class vehicle in 2020.”
Dominique Acker, an engineer involved in the preliminary development of side airbags in the Passive Safety Systems Division at ZF
Improved Protection against Dangerous Collisions inside the Vehicle
The considerably larger far-side airbag is integrated in the driver’s seat in a similar fashion to a side airbag. In the event of a head-on collision, the airbag control unit can trigger the far-side airbag shortly after the standard side airbag. In order to stabilize the far-side airbag, it is either fixed in place on the seat frame with a strap or supported by the center console. It can also be triggered when a collision takes place on the driver’s side. This is due to the fact that if there are people sitting in both of the car’s front seats, lateral acceleration can cause the two car occupants to collide with one another. In this instance, the far-side airbag can help prevent this exact scenario from taking place.
of all serious injuries or deaths suffered in head-on collisions are the result of far-side collisions.
ZF Far-Side Airbag to Be Ready for Series Production in 2020
ZF has continuously developed its far-side airbag, and can thus provide car manufacturers with a sophisticated system to meet the new Euro NCAP requirements. “We will commence with the first series production of the airbag in a compact-class vehicle in 2020,” explains Dominique Acker. With this development, Acker and his colleagues are playing an important role in moving one step closer to achieving ZF’s Vision Zero – a world with zero emissions and zero accidents.