Stepping on the gas
- By Megan Lisagor
- Mar 03, 2002
The sedan plowed into the wall and crumpled. It plowed into the wall and crumpled a second time. And a third.
The engineer ran the accident over and over, demonstrating what sets computerized crash analysis apart from road tests: no physical wreckage.
Until recently, such simulations took weeks to build, making them impractical for many research and development purposes. Now the power of the latest generation of 64-bit chips is speeding up the process, paving the way for more virtual collisions with more accurate analysis.
"It's very, very promising," said Steve Kan, director of simulation and modeling research at the National Crash Analysis Center.
The Transportation Department chartered NCAC in 1992, through funding from the Federal Highway Administration (FHWA) and the National Highway Traffic Safety Administration (NHTSA), to establish a public crash-film library and to use computers for analysis.
A decade later, much of the center's time is still spent playing high-tech mechanic as the world's largest provider of digitized car models in the public domain. NCAC has completed models for about 10 vehicles, which represent a cross-section of the most popular passenger vehicles on the road today.
To develop a replica, engineers disassemble a car and digitize its measurements, according to Kan.
Next, they input the information into a software program that reads the model and runs the computerized crash.
And then they wait. And wait.
It may take several days to complete one case, said Thomas Hollowell, chief of NHTSA's crash worthiness research division. That's too slow to test the thousands of possible crash configurations, or "all the different scenarios that make up the real world," Hollowell said. "Three days times thousands is a long time."
Imagine launching an e-mail application, then waiting a month for the inbox to appear. "It's just not practical," he said.
NCAC had been using several 32-bit and 64-bit systems to perform its work. But last year, the center began testing processors that use a new 64-bit chip design called Itanium, which was developed by Intel Corp. and Hewlett-Packard Co.
The Itanium-based systems can crank out the simulations much faster than before, mainly because they apply a new method for crunching data called Explicitly Parallel Instruction Computing. With EPIC, the Itanium chip can process multiple instructions simultaneously.
"It's significantly faster," about four times faster with respect to the old machine, Kan said. "Now we can run several parallel jobs overnight."
Its speed has allowed NCAC to catch up with the complexity of today's vehicles by reading models with millions of elements. "We're able to run more detail," Kan said. "The more refined the model becomes, the more accuracy it has."
That has immediate implications for the federal government as a regulator of the car industry.
"The only way we can afford to attack other safety concepts is through modeling," Hollowell said. Road tests cost about $80,000, according to Kan, compared with $3,000 to $4,000 for a computer analysis.
NHTSA officials hope to improve the simulation of restraint systems. "We're somewhat limited at this point in time," Hollowell said.
FHWA is using computerized analysis to study the effects of collisions between sport utility vehicles and smaller cars, and to determine the strength of guardrails.
NCAC is also working with the State Department to identify barriers for placement outside embassies that are strong enough to sustain the impact of an exploding truck.
About 15 agencies are evaluating Itanium, said Timothy Simon, a marketing specialist at HP. He added that Intel and HP are developing a solution center in Chantilly, Va., to display the technology.
This summer, Kan will begin testing Intel's newer McKinley chip, which has additional on-board memory.
"It will actually speed up the simulation even more," he predicted. "Our engineering is always hungry for computing power. We always want faster machines."
One very long road trip What has the latest generation of 64-bit chips done for crash test analysis?
Consider a Dodge Neon and a Chevrolet C1500 Truck. Simulating an accident between the two took 800 hours in 1994.
Today, with the Itanium chip, developed jointly by Intel Corp. and Hewlett-Packard Co., it takes 15 hours.
"Every bit of computing power helps," said Steve Kan, director of simulation and modeling research at the National Crash Analysis Center.