German automotive supplier ZF LIFETEC has developed a new safety technology aimed at reducing injuries in side-impact collisions. The Pre-Crash Dual Stage Side Airbag (Dual Stage SAB) utilizes a two-stage deployment system to create additional space between vehicle occupants and the impact zone milliseconds before a crash occurs.
Side collisions account for approximately 25% of all accidents in Europe and are the second leading cause of death and serious injury in vehicle crashes, according to Euro NCAP (European New Car Assessment Programme). The limited crumple zone in side impacts often results in severe intrusion into the passenger compartment, leading to serious head and chest injuries.
Harald Lutz, Senior Vice President Global Engineering at ZF LIFETEC, explained the rationale behind the new technology: "We are developing the Pre-Crash Dual Stage Side Airbag because we are convinced that in the event of a side impact, the milliseconds before an unavoidable crash are a major safety advantage."
The system works by using the vehicle's existing sensor infrastructure to detect an imminent collision. Upon receiving this signal, the first stage of the airbag deploys approximately 200 milliseconds before impact, gently pushing occupants about 60 millimeters towards the vehicle's interior. This creates crucial space for the second stage—the conventional side airbag—to deploy more effectively during the actual collision.
The Dual Stage SAB employs two separate inflators to manage the deployment stages. A hybrid inflator fills the initial 20-liter pre-crash chamber over 30 milliseconds, while a pyrotechnic inflator rapidly expands the 18-liter main airbag within 10 milliseconds of impact. To prevent pressure conflicts, the pre-crash chamber deflates as the main airbag deploys.
ZF LIFETEC has conducted various tests, including sled tests simulating complex pole impact scenarios, to prove the system's functionality. The company plans to refine the technology further, considering factors such as occupant size and varying seating positions, including those used in highly automated driving.
The Pre-Crash Dual Stage Side Airbag is designed to be integrated into vehicle seats and is potentially applicable to all vehicle classes equipped with the necessary sensor technology. Lutz noted that the Euro NCAP Roadmap 2030 already includes pre-crash functionalities, suggesting that vehicles featuring this technology may receive favorable safety ratings in the future.
ZF LIFETEC aims to develop the system to application maturity within the next few years, potentially marking a significant advancement in automotive safety technology.