Flights of Fancy: Engineers Create Virtual Hang Time

"I'm going to do a quick 360 to give you a tour of the landscape," says Mike Stefaniak E09, who's strapped into a cocoon-like sack and suspended in a triangular aluminum frame from an 8-foot high sawhorse. Mike stares out at an aerial representation of New Hampshire's White Mountains.

He straightens his right arm and sweeps the frame away from him in an arc, steering the virtual hang glider into a left-hand turn to pan across the mountains. "If you've ever seen a car with the bumper sticker, 'This car climbed Mt. Washington' that's the road right there," says Mike who is virtually thousands of feet in the air, but really only dangling inches from the carpeted floor in the middle of the Center for Scientific Visualization in engineering's Anderson Hall. (Check out a real time flight here.)

At the moment, Mike is the pilot for a mechanical engineering design team that includes fellow seniors, Daniel Thayer and Rachel Yu. With the help of their mentor and hang gliding enthusiast, Professor Lee Minardi, the team studied how real hang gliding pilots control their movements in the air. The goal was to take a program like Google Earth and create a virtual hang gliding experience that responds to a pilot's directions much in the same way as a real glider might.

Mike Stefaniak (E09) takes to the skies over New Hampshire's Mount Washington. As part of his mechanical engineering senior design project, his team, including seniors Daniel Thayer and Rachel Yu, created a hang gliding flight simulator. Photo credit: Joanie Tobin for Tufts Photo.

The responsiveness comes from a device strapped to the pilot's hang gliding frame. The student-constructed device contains accelerometers, which act to sense the direction, changes in rotation, and force of the movement the pilot is indicating. "Essentially, this is a much larger scale Wii-type application," says Rachel. "It's the same idea that your movements control what happens on the screen." 

Dan calls up another simulation. This time, Mike is flying over Paris and through the Eiffel Tower. "If I pull the bar in, I go into a dive. If I push out, I'm going up," says Mike as he narrowly avoids the tower's structural supports. Just as in a Nintendo Wii game controller, the accelerometer senses how quickly Mike tilts the frame toward himself to dive or how he rolls the frame to begin a turn.

"Probably the biggest problem was going from the sensor to the computer," says Dan, adding that Professor Chris Rogers in Mechanical Engineering helped them work out these kinks. In the program the engineers created in LabView, the computer continually recalculates where Mike is in space according to the Google Earth interface. An observer is essentially watching a series of still-frame renderings for each new calculation sped up to look like a seamless flight.

In future modifications of the simulator, Rachel says they would want their program to include thermals, rising pockets of warm air that real hang glider pilots use to maximize their flight. "Depending on where you are, you’re not sinking constantly," ays Dan.

Glider pilots look for different geographic indicators to help them control their altitude, says Minardi. "I can see that light patch on the screen there which is sand. It's been heated by the sun and may be generating lift. There's probably sinking air downwind from that lake over there as it's cooler than its surroundings."

Would these engineers like to take off into the wild blue yonder from their virtual classroom? "Absolutely!" says Rachel. Expense and time became factors for getting the engineers off the ground, but all three say their work on the project has definitely given them a hankering for hang gliding. When asked how her parents might feel about her answer, Rachel says "My mom says, 'If you go, don't tell me. Tell me after.'"

—Julia C. Keller is Communications Manager at Tufts School of Engineering