Race Car Sounds Reveal Performance - Brief Article

USA Today (Society for the Advancement of Education), June, 2000

The sound of a race car as it tears around a track reveals not only engine performance, but the driver's technique and racing team's strategy, engineers at Ohio State University, Columbus, have found. They have developed a method of computer analysis that "listens" to the pitches of sound coming from a car and extracts valuable information.

The same technique could be used to gauge the performance of any complicated piece of machinery, such as power plant turbines, suggests Giorgio Rizzoni, associate professor of mechanical engineering and director of the university's Center for Automotive Research.

Deciphering useful information from engine noise isn't easy, he explains. "An engine roars at several different pitches simultaneously, much like the harmonics of a musical instrument. The change in pitch as a car whizzes by complicates matters further."

The engineers developed equations to analyze the change in frequency of car sounds over time. At trackside, they can record the sound of a car and calculate on a computer its instantaneous speed and trajectory. "From those two pieces of information, we can figure out most everything we want to know--the strategy of the team, the engine capability, how the driver shifts gears," notes Yann Guezennec, associate professor of mechanical engineering. For instance, they compared recordings of engine sounds from two cars circling the same track, and could tell from the data the difference in transit time around curves between the two cars.

Rizzoni points out that the Navy utilizes similar technology to identify underwater sounds and to monitor the machinery on board ships. "We have advanced that technology to obtain more information efficiently and inexpensively."

Guezennec offers the example of turbines at power plants. "These are huge, expensive pieces of equipment and you can't take them apart to see how they are performing. Our technology would enable people to do that in a non-intrusive way."