

2024.09.24 Hyundai MOBIS
Mobility in the PBV era will vary significantly in many respects. Boxy vehicles, designed to optimize interior space, will become the norm, providing adaptable configurations suited to various needs. A range of innovative ideas will emerge, receiving acclaim for creating interiors that are more spacious and comfortable than ever before.
Such shifts in the era present new challenges for Hyundai Mobis as well. As automotive interiors evolve, the corresponding technologies must advance to keep pace. Their advanced airbag technology is one of the key components of this progression. As automotive layouts and usage methods transform, airbags must evolve accordingly. Hyundai Mobis, committed to ensuring safe and convenient mobility for people, has continuously developed and introduced airbag technologies that are both safer and more advanced. A notable example of this is their introduction of the world’s first 'Panorama Sunroof Airbag' in 2017.
And that is not all. Hyundai Mobis has persistently advanced its efforts throughout the year, developing the world’s first 'Self-Supporting Passenger Airbag' and 'Door-Mounted Curtain Airbag' specifically for PBVs. Both of them feature PBV-specific technology designed to reduce injury in collisions and prevent occupant ejection during rollover accidents, all while meeting the stringent safety standards of leading global markets.
In typical vehicles, the windshield supports the expanded cushion of the passenger-side airbag during deployment. This is to prevent the ‘floating effect,’ which occurs when the airbag cushion wobbles and fails to stabilize during deployment, hindering the airbag’s ability to securely support the passenger. Current airbags address this issue by enlarging the cushion so that it contacts the windshield, using it as a stabilizing support.
In contrast, the windshields of typical PBVs, which often feature a one-box design, are positioned more vertically than those in SUVs or sedans and are generally farther from the airbag. This structural characteristic complicates the use of the windshield as a support for the airbag cushion, as is common in conventional designs. To address this challenge, Hyundai Mobis developed the Self-Supporting Airbag, which relies solely on its lower structure for support, thereby effectively protecting passengers.
The self-supporting airbag eliminates the floating effect by tightly securing the cushion to the crash pad and anchoring it within the airbag housing, ensuring that the passenger is protected solely by the support between the cushion and the crash pad. Moreover, because the cushion no longer needs to make contact with the windshield, the size of the airbag can be reduced. Conventional airbags in large vehicles typically have a cushion volume of approximately 150 liters; however, with Self-Supporting Airbag technology, this volume can be decreased by over 30 liters.
PBVs primarily utilize sliding door designs to enhance the convenience of boarding and alighting. This design typically includes moving parts attached to the ceiling to aid in opening and closing, which makes it challenging to install curtain-type airbags that need to be mounted in similar locations. Additionally, PBVs often feature large windows to improve passengers' visibility outside the vehicle. In partnership with Hyundai Motor Company, Hyundai Mobis has successfully developed the world’s first wire-type door-mounted curtain airbag, which effectively provides safety even with the unique body structure of PBVs. This technology allows the cushion to deploy along wires installed on either side of the airbag, effectively securing it in the correct position and preventing passengers from being ejected through the large windows of the PBV. Consequently, the system demonstrated performance that meets the ejection mitigation standards (FMVSS 226) set by the National Highway Traffic Safety Administration (NHTSA) in self-assessment.
One of the key technologies used in the door-mounted curtain airbag for PBVs is its robust structural design, which withstands the high stresses generated during airbag deployment. This airbag utilizes an inflator that generates a maximum pressure of 350 kPa to inflate the cushion. The expansion takes place in just 0.03 seconds, applying a momentarily intense force to the wires. Given that the pressure of a standard sedan tire is approximately 250 kPa (about 36 psi), this comparison underscores the rapid and powerful inflation of the airbag cushion.
Hyundai Mobis dedicated considerable effort to material selection to bring this system to fruition. For example, high-carbon steel was chosen for the wires due to its strength, while steel alloys were utilized for the guide rings that expand along the wires. The mounting area also features a robust design to withstand the stresses involved. Additionally, one of the advantages of the door-mounted curtain airbag is its adaptability to various PBVs. This is made possible by its straightforward design, which facilitates customizing the cushion to fit the window width and allows for easy alignment of the guide rings with the wires during assembly.
Hyundai Mobis is developing a range of airbags specifically designed to accommodate the unique characteristics of PBVs, where passenger seating direction and seat position can vary freely. The "Airbag Total Package," introduced by Hyundai Mobis in 2023, exemplifies this advanced airbag technology, tailored to meet the needs of various future PBV designs. In an interior where large displays are projected onto the vehicle glass and the seats rotate accordingly, the system is designed to ensure passenger safety using face-to-face airbags, 360-degree airbags, and curtain airbags.
In the future, cars may look entirely different from those we have today. However, regardless of the era, safety will always remain paramount, as the fundamental truth is that people will always be the ones using these vehicles. Hyundai Mobis has consistently been dedicated to advancing airbag technology for the future of mobility. Their ongoing efforts include developing airbags that function even when passengers are reclining or turned around, as well as designing airbags that envelop the occupants. There is no doubt that Hyundai Mobis' initiatives will play a crucial role in shaping a safer future for mobility.