How Airbags Became a Critical Safety Feature in Cars and The Technology Behind Airbags
Driving a car these days is a necessity rather than daily leisure. Since the late 1990s, airbags have become a mandatory safety feature in all US cars, according to the National Highway Transportation Safety Administration (NHTSA).
The recent Takata airbag recalls have raised the profile of airbag technology and its functionality as a safety feature. Through this blog, you can understand a bit more about airbags as a critical safety feature and the technology behind them.
How Did Airbags Originally Get Engineered into Cars?
The purpose behind the invention of the airbag was to restrain vehicle drivers/passengers in a collision (whether or not they wore seat belts) and protect them from serious injury.
Airbags date back to the 1950s. A German engineer named Walter Linderer and an American industrial engineer named John W. Hetrick designed the first airbags. Both got patents for their inventions in 1953.
The Principal Technology Behind Airbags
The original technology behind airbags relied on compressed air systems. An airbag got deployed either due to bumper contact or driver discretion. Both Hetrick and Linderer’s airbag designs proved to be impractical as they failed to inflate fast enough during an accident. Airbags didn’t take off as a safety feature initially due to a lack of investment from automobile investors.
It was Allen K. Breed who invented an electromagnetic sensor and developed the first airbag crash sensor in 1968. He came up with a ‘ball-in-tube‘ mechanism for crash detection. The system used an electromagnetic sensor and a steel ball attached to a tube by a magnet to inflate the airbags in 30 milliseconds. It used Sodium Azide instead of compressed air for the inflation process.
General Motors was the first company to use airbags in vehicles. In 1973, they marketed their first airbag modules under the ‘Air Cushion Restraint System‘ (ACRS) and used it in a Chevrolet Impala fleet purchased by the government.
Areas Within the Vehicle Protected by Airbags in Cars Initially
General Motors 1973 Chevrolet Impala Sedans and 1974-style Oldsmobile Toronados contained a unique steering wheel with a driver-side airbag. The two cars perfectly deployed airbags in crash tests, even after 20 years. The GM’s Oldsmobile Toronado was also the first domestic US vehicle to include a passenger airbag.
Later in 1974, General Motors introduced the ACRS system to its other car models (Cadillac and Buick) and equipped them with a driver-side knee restraint, along with passenger and driver-side airbags.
How Did Airbags Originally Get Engineered into Cars?
The purpose behind the invention of the airbag was to restrain vehicle drivers/passengers in a collision (whether or not they wore seat belts) and protect them from serious injury.
Airbags date back to the 1950s. A German engineer named Walter Linderer and an American industrial engineer named John W. Hetrick designed the first airbags. Both got patents for their inventions in 1953.
The Principal Technology Behind Airbags
The original technology behind airbags relied on compressed air systems. An airbag got deployed either due to bumper contact or driver discretion. Both Hetrick and Linderer’s airbag designs proved to be impractical as they failed to inflate fast enough during an accident. Airbags didn’t take off as a safety feature initially due to a lack of investment from automobile investors.
It was Allen K. Breed who invented an electromagnetic sensor and developed the first airbag crash sensor in 1968. He came up with a ‘ball-in-tube‘ mechanism for crash detection. The system used an electromagnetic sensor and a steel ball attached to a tube by a magnet to inflate the airbags in 30 milliseconds. It used Sodium Azide instead of compressed air for the inflation process.
General Motors was the first company to use airbags in vehicles. In 1973, they marketed their first airbag modules under the ‘Air Cushion Restraint System‘ (ACRS) and used it in a Chevrolet Impala fleet purchased by the government.
Areas Within the Vehicle Protected by Airbags in Cars Initially
General Motors 1973 Chevrolet Impala Sedans and 1974-style Oldsmobile Toronados contained a unique steering wheel with a driver-side airbag. The two cars perfectly deployed airbags in crash tests, even after 20 years. The GM’s Oldsmobile Toronado was also the first domestic US vehicle to include a passenger airbag.
Later in 1974, General Motors introduced the ACRS system to its other car models (Cadillac and Buick) and equipped them with a driver-side knee restraint, along with passenger and driver-side airbags.
Changes in Airbags in the Last 20 Years
As safety concerns rose, 1980s legislation in the US passed, mandating either seatbelts or airbags in all new cars. Chrysler was the first company to offer airbags as standard equipment for safety in cars in 1988. But it was not until 10 years later in 1998 that both seatbelts and airbags became mandatory for cars.
Change in Technology
The chemical reactions of sodium azide mixed with an oxidizer are still the best propellant to inflate airbags. But now, modern cars have compressed air canisters made from either stamped stainless steel or cast aluminum to contain the propellant. It is carefully blended under a sophisticated computerized controlled process and placed in the canister as black pellets.
Change in the Fabric of Airbags
From nylon-woven airbags to neoprene-coated heavier, thick fabrics, modern cars use silicone-coated airbags. Its light, soft, heat-resistance, and long-term aging stability attributes make it the most common airbag choice.
Change in Role to Protect the Occupants
Airbags are no longer confined to the steering wheel and dashboard. Today, the doors and the inner side of the cabins also have airbags to protect the front and rear seat occupants, beyond just the driver.
Latest Technologies with Airbags
Airbag Control Unit (ACU)
Airbag Control Units (ACUs) detects and evaluates the intensity of accidents. With the increase in airbag numbers in a car, the technology handles the prompt communication for airbag deployment throughout the vehicle.
Airbags with OcSM (Occupant Safety Monitor)
OcSM technology senses the position of the occupants inside the vehicle and dynamically adapts airbag deployment to protect the occupant adequately. It provides real-time information about the occupant position to the safety control units.
Different Types of Airbags Used in Modern Cars Today
Frontal Air Bags (FABs)
FABs are located in the steering wheel and the dashboard and protect the driver/passenger during frontal collisions.
Side-Impact Airbags (SABs)
There are two types of SABs:
- The side-torso airbag
- The side-curtain airbag
Side-impact airbags are found in the seat or door panel. They inflate between the occupant and the door during a side impact to protect the occupant’s head and chest upon impact.
Knee Airbags
A knee airbag is located under the steering wheel and under the glove compartment and deploy from under the dashboard on frontal impact to protect the kneecaps of the driver/passenger.
Pedestrian Airbag
This unusual airbag is on the exterior of vehicles. During a collision, the airbag deploys to cover hard surfaces, like a-pillars and hood edges, to reduce injuries to pedestrians.
Roof Airbag
Roof airbags are the newest airbags that attach to the roof above the windscreen/windshield. It protects the driver/passenger from head injuries.
Inflatable Seatbelts
It is not an airbag, but a new approach in seatbelt design allows the seatbelt to inflate like an airbag. It spreads the force of the impact over a wider area of the body during an accident.
Other Effective Safety Features in Modern Cars Today
In the past two decades, the focus on active safety technologies like antilock-braking systems (ABS), electronic stability control (ESC), and traction control systems (TCS) have all become standard. Automobile manufacturers now offer a myriad of effective safety features for safe driving.
Safety Domain Control Unit (SDCU)
The SDCU integrates information from forward-looking environment sensors and reduces the risk (limiting the damage in the first and later phases) of an accident.
Tire Pressure Monitoring System (TPMS)
The TPMS measures the pressure inside a tire directly and transmits it to the driver. It also alerts the driver of a critical situation.
Contact Sensor System (CSS)
The CSS technology recognizes impacts and guides the driver to make more informed decisions. It enables safer automated parking, recognizes road conditions, and detects approaching emergency vehicles. The sensor also helps in the detection of vandalism.
Pressure-Based Pedestrian Protection System
This innovative system reduces the risk of death or severe injury to the pedestrian from hitting the hood.
Along with GPS, most 2021 model year vehicles come with further Advanced Driver Assistance Systems (ADAS) like
- Adaptive Cruise Control (ACC)
- Lane Departure Warning (LDW)
- Blind Spot Detection (BSD)
- Automatic Emergency Braking (AEB)
Together with passive safety systems (airbags and seatbelts), they help drivers reduce the possibility of accidents.
Conclusion
Studies by NHTSA reveal that airbags reduce death fatalities in a direct frontal crash by about 30%. The bottom line is that airbags save lives, and they have been one of the most groundbreaking safety features in vehicles in the last 30 years.