As automated driving technology advances, drivers will enjoy more flexible seating options. To ensure optimal protection during crashes, even in relaxed seating positions, ZF LIFETEC has developed an innovative dual-contour airbag. This airbag can inflate to different sizes depending on the seating position, providing enhanced safety for both drivers and passengers. ZF LIFETEC's latest development is a dual-contour airbag for the driver's side, aimed at the next generation of partially or fully automated vehicles.
With the advent of Level 3 highly automated driving, more vehicles are being approved in various countries, allowing drivers to divert their attention from traffic under certain conditions. However, they must be ready to retake control if necessary. Level 4 fully automated driving could eliminate this restriction, enabling vehicles to navigate specific routes independently. This advancement allows drivers to adjust their seat positions and backrest angles for greater comfort when the automated system is in control.
Traditionally, occupant protection is designed for standard upright seating positions. Harald Lutz, Head of Development at ZF LIFETEC, emphasized, “Our aim is to ensure that occupants in comfort seating positions also enjoy at least the same safety standards they are accustomed to in automated driving.” This goal led to the creation of the dual-contour airbag, which adapts its size to provide optimal protection in both standard and comfort seating positions.
Crash tests have shown that in a frontal crash, the classic combination of seat belt and airbag may not provide sufficient protection if the occupants are in a comfort seating position, with a backrest angle of around 40 degrees. In this scenario, the distance between the inflated airbag and the occupant is too great to effectively cushion and restrain them. The dual-contour airbag addresses this issue by inflating to a larger size when needed, ensuring better protection.
ZF LIFETEC's dual-contour airbag for the passenger side, set for application this year, served as a foundation for developing the driver’s airbag. The driver’s airbag features a two-stage function controlled by a system of bag-cushion-tethers, which adjust based on the occupant’s seating position. This adaptive mechanism allows the airbag to provide optimal protection whether the driver is in an upright or comfort seating position.
To achieve the necessary inflation for the dual-contour driver airbag, ZF LIFETEC developed a two-stage gas generator capable of filling the airbag’s large volume within milliseconds. This system can adjust the airbag’s depth by approximately 200 mm on the driver’s side. On the passenger side, the dual-contour airbag can reach up to 190 liters in volume, setting a new benchmark in the industry.
The airbag control system, integrated into the vehicle’s electronics, detects the driver’s seating position at the moment of a crash and triggers the appropriate stage of the gas generator. Additional sensors, such as interior cameras, can enhance the system's accuracy by providing detailed information about the occupant’s size, weight, and posture. This allows the airbag to adjust its inflation pressure for optimal restraint.
ZF LIFETEC’s adaptive airbag system, already in use in other series applications, exemplifies the “real-life safety” approach. By considering various occupant characteristics, the system ensures efficient and effective protection, making it a significant advancement in automotive safety technology.
