Cars are equipped with various technologies and equipment to protect passengers. For example, a car is designed to absorb the impact on the car body. Advanced Driver Assistance System, ADAS, which is beloved by consumers these days, is also considered an important safety feature beyond convenience. However, the most basic and essential elements for our safety are seat belts and airbags.
When an airbag detects impact from collision while driving, it gets activated through several processes. First, the sensors that make up the airbag system measure the level of the impact. The Sensor Diagnostic Module (SDM) determines whether an airbag should be inflated after it calculates the level of impact measured by the sensor. Then the module sends a signal to the inflator to deploy the airbags. The inflator uses the chemicals inside to create a gas, which quickly inflates the hidden airbag. For your information, all of this is done in only 0.03 to 0.05 seconds because passengers should be protected from hitting the steering wheel or dashboard.
Airbags, Evolving Over and Over
Hyundai Motor Company first deployed airbags on its New Grandeur back in 1992 for the first time in South Korea. The Airbags Grandeur featured at that moment are classified as the first-generation technologies. The first-generation airbag was to help the seatbelts, preventing the upper body of a passenger wearing a safety belt, from hitting the steering wheel or dashboard in the event of an external crash. However, the inflation pressure was high enough to injure women and children having relatively smaller bodies.
After then, the second-generation “Depowered” airbag came along, which was known to have improved the shortcomings of the first-generation airbag. As its name suggests, it has reduced the inflation pressure (approximately 30%) compared to its predecessor, reducing the impact of airbags. However, the protective performance was also declined, requiring a new type of airbag, especially for the passengers with a bigger body.
The third-generation airbag, also called the “Dual Stage” airbag, or “Smart” airbag, uses sensory information. Sensors mounted on the vehicle calculate estimated size of an impact on the passenger using a combination of factors, such as whether they are wearing seat belts or the speed of the vehicle at the moment of collisions, to control the intensity and timing of airbag inflation.
The most widely used and the latest fourth-generation “Advanced” airbag collects more detailed information, such as the occupant’s seating position, physique, and weight, through several sensors mounted on the seat. Based on this information, it actively determines whether or not airbags should be deployed, or the level of the inflation pressure, to enhance the safety of passengers.
Roof Airbags: Because Seatbelts won’t help
Many people prefer glass roofs because they can be convenient and make the cabin look larger. However, passengers can also get injured by being thrown out of the sunroof – even panoramic these days – during an accident. Of the 13,700 subversive accidents that occurred in North America, 17 percent of the cases were reported where passengers got thrown out of the sunroof. The world’s first roof airbag developed by Hyundai Motor Group is a new technology to reduce such damage.
Roof airbags are compressed and stored in the ceiling. According to data released by the U.S. National Highway Traffic Safety Administration(NHTSA), experiments under various conditions showed that it has been effective in preventing passengers from leaving through the sunroof. Roof airbags spread in 0.08 seconds in the event of a rollover accident and prevent passengers from bouncing off the sunroof, reducing head and neck injuries.
The autonomous cars with a glass body will feature a spacious cabin, which highly likely to increase the chance that the passengers get thrown out of the car in a rollover. The roof airbag, then, will become a necessary element.
Center side airbag to prevent collision between passengers
According to The European New Car Assessment Programme(Euro NCAP), which oversees car safety tests in European markets, side collisions are the second most fatal and injured type of accident. Therefore, most of the latest cars are equipped with curtain airbags as well as side airbags to prepare for shocks from the side of the body. However, side airbags and curtain airbags do not prevent side-to-side collisions from causing occupants to bump into each other. In fact, statistics released by the European Automobile Manufacturers Association (ACEA) show that 45% of the secondary damage caused by collisions, embedded materials and debris between passengers in side crashes.
Furthermore, in actual accident situations, collisions occur from various angles, making it difficult to completely prevent secondary damage with just the airbags fitting conventional tests. To prevent such damages, vehicle safety assessment agencies in the major markets have created a “Far-side” test that has stricter standards for side-impact tests. And Hyundai Motor Group’s center side airbag is the safety feature for such cases.
The center side airbag is mounted on the right side of the driver’s seat and inflates in the event of a side impact. At this time, the driver’s upper body movement is suppressed to prevent secondary accidents such as colliding with the interior materials or hitting the head with the passenger. In addition, it prevents neck injury from strong side collisions, which greatly reduces damages.
A Whole New Safety Feature for Self-driving Era: Hug Airbag
The roof airbag will be more effective in vehicles with a panoramic sunroof in the future. Autonomous cars in the future will also benefit from the roof airbag since the passengers will be sitting in all different directions. Therefore, future airbags are expected to play a different – enhanced – role when it comes to protecting the passengers.
HMG has recently unveiled its Hug Airbag, and it contains the hints of our future airbags. The Hug Airbag consists of three ‘chambers’; each chamber works differently depending on the location. The upper chamber is to protect the head and the chest of a passenger. The center chamber, unlike other chambers, can bend over to protect the passenger from the back. The lower chamber is to protect the pelvis.
Each chamber is firmly connected with a tether, and this is how Hug Airbag can hold the body tight in a crash. Researchers are trying to find the optimal way for each six camber to be docked in a tether. And of course there is more room for improvement; Hug Airbag needs to be suitable for any passenger of size, to name one.
Though airbags have been essential elements for the safety of passengers, the development of the airbags is still not fully done yet. The era of autonomous driving is to come, and HMG will keep working on the research for better airbags.