New Technology for Kicking Tires

CAD illustration courtesy of Dr. El-GindyTires may not be high on the list of features that make the car-buying public want to reach for their wallets, but headlines over the past several months may have consumers paying greater attention to their wheels. Last August, Bridgestone Corp.'s Firestone recalled 6.5 million tires—mostly used on Ford Explorers—that were linked to 159 deaths in the U.S. and overseas.

Now researchers at Penn State, using the Pam-Shock virtual-testing software developed by France's ESI Group, have developed a computer simulation that can virtually "road test" a tire long before the rubber meets the road. Already two manufacturers, Firestone and Dunlop, have expressed interest in the research, says Moustafa El-Gindy, director of the Crash Safety and Vehicle Simulation Research Centers at the school's Pennsylvania Transportation Institute.

El-Gindy says tires are critical to vehicle safety—especially at high speeds—but that the industry has not taken advantage of the available testing technology. CAD illustration courtesy of Dr. El-GindyA tire's trouble zone occurs when it hits its maximum speed and a "standing wave" develops that can deform the tire, raise its temperature, and cause it to fail. Currently, to test for this, manufacturers run a tire on a test drum. But using the Penn State simulator, a virtual tire can be run on a virtual drum at speeds up to 280 mph. Even road bumps can be built into the simulation. The virtual testing won't mean an end to actual road tests, but it can help designers spot flaws earlier in the design process. That "will help increase safety factors while saving time and money," El-Gindy says. And that's nothing to kick at.

An Unreal Driving Experience

photographs courtesy of NADS
The new $56 million simulator at the University of Iowa uses 360-degree computer-generated images and high fidelity sound to recreate realistic driving experiences.
The world's ultimate virtual reality machine should be going online within a few weeks at the University of Iowa. But don't go rushing out for tickets to ride—the National Advanced Driving Simulator is no fairground attraction, it's big and serious science. In the driver's seat is L.D. Chen, an Iowa mechanical engineering professor who was recently named NADS director. It's a job that places Chen in the headlights of controversy, since the $56 million computer simulator has attracted a number of skeptics.

NADS will use cutting-edge virtual reality technology to help researchers study the human factor in highway accidents. The National Highway Traffic Safety Administration, which ponied up $44 million of the cost, estimates that 90 percent of the 42,000 highway deaths a year are caused by human factors—among them too much alcohol, fatigue, effects of medicine, and talking on cell phones.

Testing for these elements in real-life situations is too dangerous, and supporters say NADS will allow scientists and engineers to conduct tests in the safety of a laboratory. The system takes computer simulation to new levels using 360-degree, computer-generated images and high-fidelity sound to realistically recreate driving experiences. The simulator can also replicate the interiors of many different makes of cars and trucks, and even heavy construction equipment. Findings will be used to help improve car and highway designs. Chen, who has taken the simulator on "test drives," says the effects are "really, really impressive."

Be that as it may, critics—including the Center for Auto Safety and the Insurance Institute for Highway Safety—are not impressed. They call the simulator too costly and predict that it will yield dubious results. When occupants know they're being tested, they argue, they behave differently. But Chen is convinced the critics can be won over. "I remain very optimistic that it will do a lot of things that can't otherwise be accomplished," he says.

photographs courtesy of NADS
Study participants will be able to perform all sorts of risky driving maneuvers in this Chevy Malibu frame, which will help researchers gather data on human factors in highway accidents.

Chen, who has been acting director since 1998, took over from founding director Edward Haug, who is developing research projects for NADS. Chen, who has been involved in automotive and transportation projects throughout his career, was a natural choice for the job. He is heading one project that uses computer simulation to predict fuel-cell performance, another that will lead to the creation of a lab for ongoing airbag research, and is also principal investigator for a NASA project to design jet engines that burn more reliably. Chen was the school's mechanical engineering department's chairman from 1992 to '98, and first came to Iowa as a faculty member in 1982. He received his doctorate and master's in mechanical engineering from Penn State, where he was an assistant professor in 1981. His bachelor's degree is from the National Taiwan University.

Despite his heavy research workload, Chen still manages classroom time. He teaches a course in combustion/propulsion engineering. "It's fun," he says of teaching, and also helpful, as it forces professors to keep their thinking fresh. Nonetheless, he admits, it's also time-consuming. Chen estimates that, including preparation time, one course requires 15 hours of his time each week. "There's certainly no 40-hour weeks," he says, chuckling. Sounds like he could also volunteer to "drive" the simulator on Friday evenings, to help measure how long hours affect driving ability.