DETROIT — Urethane is helping turn out a smarter dummy. While the auto industry has used plastic models in crash tests for years, a Plymouth, Mich.-based safety specialist and dummy maker now is turning out one with a urethane-based body designed to more closely imitate human flesh and motion.
The product helps determine exactly how people sit in cars so that automakers can calibrate advanced air bags designed to fire at lower forces for smaller people.
The National Highway Traffic Safety Administration will begin analyzing one of First Technology Safety Systems Inc.'s prototypes in April as it considers whether to make it a regulatory standard for some tests.
Automakers and auto suppliers from North America, Europe and Japan already are ordering the Occupant Classification Anthropomorphic Test Device, according to Gordie Morgan, director of technical marketing for First Technology.
"The most important attribute in the development was to assure an accurate human geometry was used in conjunction with a humanlike flesh," Morgan said. "This is not an easy task, especially since the human body is an extremely technical and complicated machine."
But the OCATD-5 and OCATD-6, using a proprietary urethane blend to simulate flesh and tissue layered over a skeletal structure designed around the proportions of a small female and 6-year-old child, is the flexible solution First Technology wanted, he said.
"It's very humanlike," Morgan said. "It can even cross its legs."
First Technology displayed the OCATD as part of the Society of Automotive Engineers 2000 World Congress, held March 6-9 in Detroit.
The dummies began through two separate studies at First Technology. One was funded with help from the Alliance of Automobile Manufacturers to find a better way to develop sensors for advanced air bags. The second was done in conjunction with auto supplier Lear Corp. to demonstrate wear and tear on seats.
Traditional hybrids, made of PVC, are designed to determine the way humans move in a crash — not how they sit in a car. They just don't feel or act like a human, said Ash Galbreath, vice president of advanced engineering and validation for Southfield, Mich.-based Lear.
"The goal was to have something that would be more like actual motion," Galbreath said.
The air-bag sensor study with the alliance, meanwhile, focused on finding a way to show pressure points in a seat so air-bag manufacturers can more accurately develop sensors that control a bag's firing force, said Steve Moss, technical director for First Technology.
"Essentially, the air-bag systems have to distinguish between an adult and a child," he said.
The industry now relies on actual humans for the seating studies, but they are not always available when a company is ready for a test, Morgan said.
The parallel projects dovetailed into the search for a material that could better simulate human flesh, he said.
First Technology launched a study on various urethanes, sorbethanes, silicones and other materials while also researching physicians' work on pressure sores and muscle tone.
"We were trying to replicate the same pressure pattern that a human would have on a seat," Morgan said. "We've gone through a number of different plastics trying to find just the right one."
The dummies also will go into tests for comfort, vibration and acoustics.
First Technology also is building dummies in a variety of other sizes to mimic older children and adults.
"It's really catching on," Morgan said.