Not just any airbag, but a Ticker Tape Air Bag (TTAB) from Key Safety Systems, Inc. (Sterling Heights, MI; www.keysafetyinc.com) that goes beyond the requirements set out for advanced airbags for protecting front seat passengers. It eliminates the need to either suppress airbag inflation or default to a low-risk mode to protect an out-of-position occupant (a.k.a., “OOPO”).
The “ticker tapes” are thin sensor tapes with alternating dark and light squares that are sewn to the inside of the airbag cushion. They travel past an optical sensor that reads the speed of the tapes during deployment. Any change in output, whether from contact with a smaller passenger nearer the bag or an OOPO contacting one part of the bag, causes the internal algorithm to instantly determine the amount of inflation gas necessary to safely cushion that passenger.
Unlike a dual-stage bag, the TTAB has more than two vent protocols. In fact, the amount of gas it releases can vary infinitely from 0% to 100%, depending on the situation. Once the proper inflation volume is determined, a pyrotechnic piston opens a flap that forces the excess gas away from the cushion. Smaller occupants seated closer to the instrument panel receive a “softer” inflation, larger occupants a “stiffer” one, and OOPOs get one that is somewhere in-between. Robert Block, vice president Engineering & Program Management, North American Airbag & Inflator, Key Safety Systems, says the unit, “offers just the right inflation for the situation.”
There’s a reason. The system costs less than a conventional advanced airbag design because it eliminates the need for a separate occupant sensor map, occupant warning light, and the costs of integrating, validating and calibrating a dual-stage system. Plus, the TTAB can be packaged in the same space as today’s passenger airbag systems, is the same weight, and is less susceptible to wear since all of the components are located within the passenger airbag module. Block estimates the TTAB has a $25 to $45 per vehicle piece cost advantage over suppression systems.
Yes and no. The TTAB is ready for use in 2008 model year programs, and has shown a distinct advantage over conventional airbag designs in light truck applications that place the module in the leading edge of the instrument panel instead of under the windshield. However, some OEMs have expressed concern that fitting the module to some, but not all, of their vehicles would leave them open to lawsuits. (Block estimates the TTAB shows a 60% to 80% injury reduction compared to non dual-stage airbag systems.) Resolving this dilemma may prove to be the biggest hurdle the company has to overcome.
Block says his engineers need to have the packaging data, vehicle interior geometry, and a detailed passenger compartment map. At that point, his team can begin calibrating the algorithm for the application. And since Key Safety Systems makes the complete unit, it retains control over all aspects of safety, quality, and logistics.