ROANOKE TIMES
Copyright (c) 1997, Roanoke Times
DATE: Saturday, March 15, 1997 TAG: 9703170034
SECTION: NATIONAL/INTERNATIONAL PAGE: A-1 EDITION: METRO
DATELINE: WASHINGTON
SOURCE: ROBERT S. BOYD KNIGHT-RIDDER/TRIBUNE
The Defense Department and several engineering schools are developing ``micro air vehicles,'' that could scout out enemy snipers, sniff poisonous chemicals or locate hostages in occupied buildings.
If you think model airplanes are just toys for kids, think again. The Defense Department and several top engineering schools are developing tiny aircraft that could scout out enemy snipers, sniff poisonous chemicals or locate hostages in occupied buildings.
Bearing names like Flyswatter and Dragonfly, the gadgets range from the size of birds to butterflies. One experimental helicopter can perch easily on a peanut.
These ``micro air vehicles,'' as they are known, pose excruciating challenges to their designers and builders, stretching the limits of computer, optical and aviation technology.
Wind gusts that a large airplane shrugs off can be disastrous for a miniature flying machine. In order to land safely, the tiny planes must be able to measure their altitude above the ground in inches. Engines, flight controls and sensitive detectors can weigh only ounces.
To be useful despite their minuscule size, the planes must lug cameras, chemical and biological sensors, radio transmitters and antennas.
``The technological difficulties in making this prospect real are immense,'' said Richard Truly, vice president of the Georgia Tech Research Institute.
The institute hosted a conference last month for 60 military and civilian experts on micro-flight, representing the Pentagon, major aerospace companies and eight universities. They spent two days discussing ways to surmount the obstacles facing their ambitious enterprise.
At least eight prototypes will be tested April 5 in a hayfield near the University of Florida at Gainesville. The object is to fly a remote-controlled vehicle a half mile from the launch site, photograph a symbol on the ground hidden by a five-foot fence, and return to the starting point. The smallest device that accomplishes the mission will be the winner.
Despite the difficulties, the project's backers are enthusiastic. They see many possible uses for their devices, if they can get them to work.
``Micro air vehicles can help rescue workers search ruins for survivors, police monitor hostage situations, traffic managers respond to incidents and soldiers locate snipers,'' Truly, a retired Navy admiral, wrote in a letter to the conference participants.
For example, David Jenn, an associate professor at the Naval Postgraduate School in Monterey, Calif., is working on a helicopter with six-inch rotors. It will carry an infrared camera to conduct video surveillance of the inside of a building.
To control their mechanical hornets, the conferees discussed the need for sophisticated computer systems, using advanced artificial intelligence techniques.
``It seems essential that micro air vehicles be designed for autonomous flight, in which they can guide themselves to and from a target without human intervention,'' said Robert Michelson, a Georgia Tech engineer.
He noted that the devices will often be out of the line of sight from a command center - for example, during a rescue operation inside a building - and will have to fly unattended.
``The trend in navigation software will be doing more with less,'' said Paul DeBitetto of the Charles Stark Draper Laboratory in Cambridge, Mass. Eventually, he said, the guidance, navigation and control functions could be combined on a single computer chip.
Conventional airplane wings and control surfaces won't be adequate for pint-sized craft flying at very low speeds, according to Robert Englar of the Georgia institute's aerospace laboratory.
Designers are experimenting with flexible, pneumatic wings that can adjust to rapidly changing air currents, especially when dodging trees or walls.
Wings that flap like a butterfly's may be required for aircraft smaller than three inches across, according to James McMichael, program manager for Micro Air Vehicles at the Defense Advanced Research Projects Agency.
To provide power, AstroPower Inc. of Newark, Del., is developing a minute solar panel that can be glued to the skin of the aircraft. Other models use tiny internal combustion engines that can operate on a thimbleful of fuel.
Eventually, backers hope to be able to build fleets of the mini-planes at a cost of about $1,000 apiece.
LENGTH: Medium: 84 linesby CNB