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Harnessing Fuzzy Logic
May 10, 2006

A Calvin senior engineering student had a rare opportunity for an undergraduate when he presented a paper on “fuzzy logic” at the 2006 IEEE International Electro/Information Technology Conference, held May 7-10, at Michigan State University’s Kellogg Center.

The event was sponsored by the Institute of Electrical and Electronics Engineers (IEEE), Inc. He originally wrote his paper for a student contest and then submitted it to the IEEE conference.

“I didn’t think they’d select it,” he said.

Bryan Klingenberg spoke on “Fuzzy Logic for Harmonic Distortion Diagnosis in Power Systems” at the conference, whose keynote speaker was the inventor of fuzzy logic.

“It is a prestigious conference,” said Calvin engineering professor Paulo Ribeiro. “I think this is a remarkable opportunity for a student.”

Klingenberg, who will graduate May 20, has also designed a Web site for teaching fuzzy logic to undergraduates, an effort funded by the Digital Studio at Calvin.

His current work will be used by Ribeiro in his work on shipboard power systems for the new class of U.S. Navy ships, sponsored by the Office of Naval Research.

“Bryan’s work is all the more impressive because it is going into industrial application at the research level right away,” Ribeiro said.

Fuzzy logic is a system that uses several inputs, not just one, to make a decision.

“It functions almost like a human,” Ribeiro said. “Our decisions are very fuzzy. You don’t decide I’m going to do this for one simple reason. We are always thinking in a fuzzy way and making decisions based on multitude of inputs or data information.”

“You use it for control of a system,” added Klingenberg. “Common applications of fuzzy logic are anti-lock brakes, heating, ventilation and air conditioning. There’s a subway system in Japan that is completely controlled by a fuzzy controller.”

Ribeiro described how fuzzy logic works in anti-lock braking systems: “There is a certain frequency that is more appropriate to bring the car to a stop depending on the speed of the car, the temperature and the humidity of the air. There’s a computer in the system that automatically calculates those things to choose the correct frequency for braking.”

Klingenberg used fuzzy logic to diagnose harmonic distortion in power systems.

“Harmonic distortions are extra, unwanted oscillations in the signal that can adversely affect many systems by causing erratic behavior and overheating-either immediate equipment failure or shortened equipment life,” he said. “So, you have something that’s supposed to last for 10 years, and it lasts for five years, or it will just blow up.”

The model devised by Klingenberg uses a fuzzy logic-based controller to monitor temperature and several harmonic voltage inputs, which indicate the degree of danger that the system is under.

Klingenberg first worked on fuzzy logic as a project through Ribeiro’s class.

“I knew that I wanted to study this,” Ribeiro said, “but I needed someone to help me with it. He did most of the work on his own. That was the remarkable thing. I was impressed with how he was able to accomplish this on his own.”

Klingenberg went on to create the website for Digital Studio.

Headlining the IEEE conference, a forum for researchers and practitioners in academia and industry, was Dr. Lotfi Zadeh, the man who in 1965 invented fuzzy logic.

“At the time, it wasn’t very well accepted-the applications of his theory-at least in the west. In the east, in Japan, they took fuzzy logic and ran with it and made tons of applications,” Klingenberg said.

The Institute of Electrical and Electronics Engineers (IEEE) is the world's largest technical professional society. Founded in 1884 by a handful of practitioners of the new electrical engineering discipline, today's Institute is comprised of more than 320,000 members who conduct and participate in its activities in 152 countries.

~written by media relations staff writer Myrna Anderson