Airbag

The airbag provides an energy-absorbing surface between the vehicle's occupants and a steering wheel, instrument panel, body pillar, headliner, and windshield.

[9] The airbag "for the covering of aeroplane and other vehicle parts" traces its origins to a United States patent, submitted in 1919 by two dentists from Birmingham, Arthur Parrott and Harold Round.

[20][21] Although airbags are now required in every automobile sold in the United States, Hetrick's 1951 patent filing serves as an example of a "valuable" invention with little economic value to its inventor.

[29] In the early 1970s, General Motors began offering cars equipped with airbags, initially in government fleet-purchased 1973 Chevrolet Impala sedans.

[35] In 1974, GM made its ACRS system (which consisted of a padded lower dashboard and a passenger-side air bag) available as a regular production option (RPO code AR3) in full-sized Cadillac,[36] Buick and Oldsmobile models.

[37] The passenger-side airbag protected both front passengers,[37] and unlike most modern systems, integrated a knee and torso cushion while also having a dual-stage deployment dictated by force of the impact.

Some safety experts advocated a performance-based occupant-protection standard rather than one mandating a particular technical solution (which could rapidly become outdated and prove to not be a cost-effective approach).

[43][44] Chrysler also began featuring the airbags in advertisements showing how the devices had saved lives that helped the public know the value of them and safety became a selling advantage in the late 1980s.

[47] Driver and passenger airbags became standard equipment in all Dodge Intrepid, Eagle Vision, and Chrysler Concorde sedans ahead of any safety regulations.

Developed by Autoliv and Honda R&D in Ohio, United States, this new airbag design features three inflatable chambers connected across the front by a "noninflatable sail panel."

The goal of the tri-chamber airbag is to help "arrest high-speed movement" of the head, thereby reducing the likelihood of concussion injuries in a collision.

Roll-sensing curtain airbags are designed to stay inflated for a longer duration of time, cover a larger proportion of the window, and be deployed in a roll-over crash.

SUVs and pickups are more likely to be equipped with RSCAs due to their higher probability of rolling over and often a switch can disable the feature in case the driver wants to take the vehicle off-road.

In 2009, Toyota developed the first production rear-seat center airbag designed to reduce the severity of secondary injuries to rear passengers in a side collision.

In 2008, the new Toyota iQ microcar featured the first production rear-curtain shield airbag to protect the rear occupants' heads in the event of a rear-end impact.

[90] Another feature of the Toyota iQ was a seat-cushion airbag in the passenger seat to prevent the pelvis from diving below the lap belt during a frontal impact or submarining.

[104] Suppliers of SRS airbags include Autoliv, Daicel, TRW, and JSS (which owns Breed, Key Safety Systems, and Takata).

Oftentimes, ACUs log this—and other—sensor data in a circular buffer and record it to onboard non-volatile memory, to provide a snapshot of the crash event for investigators.

Once the requisite threshold has been reached or exceeded, the airbag control unit will trigger the ignition of a gas generator propellant to rapidly inflate a fabric bag.

The signals from the various sensors are fed into the airbag control unit, which determines from them the angle of impact, the severity, or the force of the crash, along with other variables.

It was found that these non-azide reagents allowed for a less toxic, lower combustion temperature reaction, and more easily disposable airbag inflation system.

The microscopic mechanical element moves in response to rapid deceleration, and this motion causes a change in capacitance, which is detected by the electronics on the chip that then sends a signal to fire the airbag.

An igniter starts a rapid chemical reaction generating primarily nitrogen gas (N2) to fill the airbag making it deploy through the module cover.

In small amounts this chemical can cause minor irritation to the eyes and/or open wounds; however, with exposure to air, it quickly turns into sodium bicarbonate (baking soda).

On 11 July 1984, the United States government amended Federal Motor Vehicle Safety Standard 208 (FMVSS 208) to require cars produced after 1 April 1989 to be equipped with a passive restraint for the driver.

This was due to the injuries caused by first-generation airbags, though FMVSS 208 continues to require that bags be engineered and calibrated to be able to "save" the life of an unbelted 50th-percentile size and weight "male" crash test dummy.

In 2014, General Motors admitted to concealing information about fatal collisions caused by defective ignition switches that would abruptly shut down a car (including its airbags).

Improvements in sensing and gas-generator technology have allowed the development of third-generation airbag systems that can adjust their deployment parameters to the size, weight, position, and restraint status of the occupant.

The Cockpit Air Bag System (CABS)[157] consists of forward and lateral airbags, and an inflatable tubular structure (on the OH-58D only) with an Electronic Crash Sensor Unit (ECSU).

[158] It is the first conventional airbag system for occupant injury prevention (worldwide) designed and developed and placed in service for an aircraft, and the first specifically for helicopter applications.