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UA's MAV team competed in the surveillance event at the 9th International Micro Air Vehcile Competition with an MAV built on this design. The plane has a 12-inch wingspan and is powered by an electric motor. |
The University of Florida, a long-time MAV powerhouse, took first place overall.
MAVs are tiny, radio-controlled airplanes — some have wingspans of only four inches — equipped with video cameras. They're designed for reconnaissance and can be used in search-and-rescue, law enforcement, military surveillance, or any situation too dangerous or time consuming for a human observer.
UA Ornithopter Flew Like a Plane
This was the second year that ornithopters participated in the event. These airplanes generate lift and forward motion with flapping wings, mimicking the aerodynamics of birds and insects.
The ornithopter competition involves building the smallest radio-controlled ornithopter that can fly the most laps around a pylon course in two minutes. The pylons were spaced about 40 feet apart and the ornithopters fly either an elliptical course around them or a figure 8 through them.
 UA's MAV team has set the new standard for micro-sized, radio-controlled ornothopters. |
The figure 8 laps earn twice as many points as elliptical laps, giving the edge to maneuverability over speed. The final score is calculated by dividing the number of laps flown by the ornithopter's largest dimension squared.
Before the competition flights began, aerospace engineering graduate student Bill Silin demonstrated what the UA team believes is the world's smallest radio-controlled ornithopter. With a wingspan of only seven inches, it drew lots of interest from competitors and spectators alike.
UA flew a slightly larger design, with a wingspan of about nine inches, during the competition. Silin designed and built the ornithopter, but Jeremy Tyler, who just graduated with a bachelor's degree in aerospace engineering, flew the competition laps.
"Although it was slightly larger than Bill's smallest ornithopter, it probably was still the world's second smallest radio-controlled ornithopter," Tyler said. "It was very fast, powerful and maneuverable."
Silin and the UA team have now set the new standard for micro-sized ornithopters. Only a year ago, at the 8th International MAV Competition, ornithopters had difficulty staying up in anything but still air and seemed only partially under control. (For more on last year's event, click here.)
"This year, our ornithopter flew like an airplane," said MAV team captain A.J. Kochevar. "We could fly it under complete control 300 feet away. It was that stable." Kochevar graduated with a bachelor's degree in mechanical engineering and is now finishing a degree in aerospace engineering.
Surveillance Calls for Flying by Video
During the surveillance competition, teams tried to fly the smallest MAV that could return a legible image of a symbol located about 4/10ths of a mile (600 meters) from the launch point. The symbol was about six feet square and enclosed in a 3-foot-high fence.
After the UA plane was launched, Tyler flew it until it was nearly out of sight.
Then Kochevar, who was wearing video goggles that displayed an image from the plane's forward-looking video camera, took over and flew the plane as though he was sitting in its cockpit. With a wingspan of just over five inches, this plane was the smallest one entered in the surveillance competition. It was so small that the camera had to be mounted behind the propeller, lowering visibility. The plane's tiny black-and-white camera also produced washed out images in direct sunlight.
"Luckily, there was a road that went out near the target, so we could follow that and make a last-ditch effort to get to the target," Kochevar said. "Unfortunately, I got disoriented and turned left instead of right. But we did get out there. Hopefully next year my piloting skills will be better and we can get out there with a really small plane."
After the smaller plane missed the target, UA switched to a plane with a 12-inch wingspan for the second and third tries. This plane easily captured an image and returned to the staging area.
This was the smallest plane to ever acquire an image and return during an International MAV Competition. Most planes, including this year's winner, use a forward-facing camera. They fly to the target and then dive so the camera can see the target, eventually crashing near or into it.
UA's plane used a downward-facing camera and flew in what the team calls "stability augmented mode." An autopilot that the UA team designed and built in collaboration with two French MAV enthusiasts limited the plane's roll angle to 35 degrees and its pitch angle to 20 degrees. In this mode, the autopilot controls the plane's aerodynamics, making it nearly crash-proof, and the pilot steers it like a car that can travel in three dimensions.
The UA team watched the plane's progress on a computer-screen map as it radioed back its position.
"The plane just goes where you point it and this makes it very easy to fly," Tyler said. "In fact, the plane doesn't even have to be in sight." (For more information and technical details on the team's autopilot, click here.)
New Directions for the Competition
"It doesn't seem practical, as far as real-world applications, to just crash the airplane into whatever target you're trying to acquire," Kochevar noted. "We would like to see the competition changed so that you get points for either acquiring an image of a second target or bringing the plane back to the launch area."
The team also would like to see autonomous flight added to the competition. In this event, the plane would fly itself, completely hands-off, from the time it left the launch area to the target and back.
While this sounds difficult, the UA team demonstrated that it can be done. During a demonstration flight, the team switched their autopilot to fully automatic mode. The plane flew itself to the target, sent back a video image and returned to the staging area, where it was landed under manual control.
"We didn't have room for an autonomous landing," Kochevar said. "If we'd had another 100 yards of runway, it could have landed on its own. But we did demonstrate that autonomous flight is a reality and could become a separate event next year."
Tyler noted that three U.S. schools and three European schools already are capable of entering an autonomous flight competition.
The Endurance Competition
The endurance competition involved building the smallest MAV that can fly for the longest time, up to 15 minutes. The winner was determined by dividing the flight time by the MAV's largest linear dimension cubed
This year, Korea's Inha University broke the four-inch barrier for the first time, successfully flying an MAV whose longest dimension was only about 3.75 inches. This was nearly three-quarters of an inch smaller than last year's winner.
UA entered an airplane with a wingspan of about 5.1 inches and it flew for the full 15 minutes.
The endurance planes are built solely for small size and light weight and don't carry video cameras. So they're usually smaller and lighter than the planes that are entered in the surveillance competition.
The UA team hopes to build a much smaller plane for next year's competition based on an elliptically shaped wing. UA's MAVs had squared off wingtips this year, a design the team adopted about a year ago after experiencing problems with elliptical wings.
The UA team hopes to enter an improved elliptical wing next year. This design will produce less drag, which will lead to a more efficient and smaller airplane.
"The design we're working on kind of blends last year's design and this year's design," Kochevar explained. "Unfortunately, we hadn't finished testing in time for the competition, and there are some problems that we still need to work out." (For more on MAV design, click here.)
Others on the UA team in Korea were aerospace engineering master's student Motoyuki Aki, MAV team member Sean Har, and the team's advisor, Sergey Shkarayev, assistant professor of Aerospace and Mechanical Engineering.
Final Results
The final results for the competition are:
Overall
1. University of Florida
2. University of Arizona
2. Konkuk University
3. Inha University
4. Brigham Young University
Ornithopter:
1. University of Arizona
2. Inha University
3. University of Florida
4. Konkuk University
Surveillance
1. Konkuk University
2. University of Florida
3. University of Arizona
Endurance
1. Inha University
2. Konkuk University
3. University of Florida
4. University of Arizona
Design Report
1. University of Florida
2. Brigham Young University
3. University of Arizona
4. Konkuk University
5. Dayton Christian High School
Participants:
Andong National University (Korea)
Brigham Young University (USA)
Chosun University (Korea)
Dayton Christian High School (USA)
Gyeong San National University (Korea)
Hankuk Aviation University (Korea)
Inha University (Korea)
Kokam RC (Korea)
Konkuk University (Korea)
Lehigh University (USA)
Rochester Institute of Technology (USA)
University of Arizona (USA)
University of Florida (USA)
UA's MAV team is sponsored by:
• ASUA (Associated Students of the University of Arizona)
• The New Nose Co., Inc.
• Texas Instruments
• U.S. Army Ft. Huachuca Battle Labs
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