Defense Technology International - December 2007 - (Page 25)

DOWN TO THE WIRE Small UAVs are designed to recharge on power lines BETTINA H. CHAVANNE•WASHINGTON mall unmanned aerial vehicles (UAV) are effective about $100,000 each. “We landed two of them, and ﬂew those battleﬁeld surveillance platforms. But they su er from planes many times,” McKinley says. The tests showed it was possible to connect to a power line, limited battery power, which a ects their range and and that a UAV could withstand ﬂying into one at 40 kt. A their sensors’ e ectiveness, often making them expendable. A solution may lie in overhead power lines. A program by latching mechanism, however, still needs to be perfected. Part of the Phase II SBIR also involves developing a powerDefense Research Associates (DRA) and the Air Force Research Laboratory (AFRL) seeks to develop a small UAV that line navigation capability. “There’s a problem when a small can land on a power line and recharge its battery by drawing UAV gets [electronically] jammed but keeps ﬂying,” notes McKinley. energy from the cable. If this happens, a UAV can be guided by power-line navigaThe PLUS (Power Line Urban Sentry) program seeks to create an autonomous, reusable platform with a long range tion. Operators would program coordinates for power lines into the UAV so that it folthat operates in conlows a path that can be fined areas, such as correlated back to any an urban battlefield. GPS start location. Surveillance and data If the GPS system collection would be becomes jammed, the improved because stored power-grid map sensors recharge with can be used to identhe battery. tify the UAV’s Dayton, Ohio-based position, DRA has received a McKinley Small Business Insays. novation Research The UAV (SBIR) grant from could be 100 mi. out and the Defense Dept. and still transmit data. “Powis currently working er lines are like highways on prototypes with in the sky,” he says. AFRL in Phase II of Even if a UAV is the program. shot down, it will proThe effort began Pusher-prop ﬂying wing is one conﬁguration for a small vide a data waypoint three years ago when UAV that recharges by latching onto power lines. for troops. “You know Patrick Marshall, a senior electronics engineer at AFRL, began investigating meth- someone there is armed,” Marshall remarks. “They know about ods of charging small UAVs by ﬂying them close to power lines. your UAV, but you know you want to look at that area.” An energy-harvesting UAV could be equipped also with But the process was ine cient. “The best we could get was multiple sensors. “The idea is that when you’re recharging, micro-watts of power,” he says. So Marshall built a toroidal test box that clamped around you have all that power from the line to do whatever you a power line to draw energy from the cable. The design was need,” McKinley observes. One issue about recharging is detection. Can a small UAV successful, though the latch mechanism needed work. Marshall also worked with Mike McKinley, DRA’s hard- be disguised? Rick Lind, an associate professor of mechaniware engineering manager. They ran tests at Wright-Patter- cal and aerospace engineering at the University of Florida, son AFB, Ohio, by putting a prototype on a power line and thinks so. Lind works with aircraft morphing technology and runs retrieving data through a radio-frequency link to see what happened as it charged, McKinley says. The battery charged a facility called the Center for Morphing Control. One goal of the PLUS program is to create a small UAV that seems to in under three hours. “From that point,” McKinley recalls, “the thinking was, disappear by morphing into a shape that doesn’t look out of ‘if we can get the charge, we can [find a way to] land on place on a power line. So Marshall and McKinley asked Lind to join their e orts in 2006. the line.’” “He made a small UAV look like a Coke can,” Marshall reThen DRA hired a radio-controlled-aircraft operator to land model airplanes on power lines and attempt to latch on. In a calls. The ﬁrst prototype ﬂights are expected in 2008. I span of nine months, they tested ﬁve or six models at a cost of www.aviationweek.com/dti U.S. AIR FORCE RESEARCH LABORATORY S DECEMBER 2007 DEFENSE TECHNOLOGY INTERNATIONAL 25 http://www.aviationweek.com/dti

Table of Contents Feed for the Digital Edition of Defense Technology International - December 2007

Defense Technology International - December 2007 Contents Around the World Science Watch Tech Watch BrahMos: Ramjet Ship Killer r-e-s-p-e-c-t Deja Vu Trump Card Dubai Demos Agile Helos Joint Force Online Charge UGVs Creep, Crawl to Victory Sweet Ride Fast, Lethal Ship Defense Networking Stealth: Why Raptors Can't Talk The Net Cutting Edge First Person In Review Insight

Defense Technology International - December 2007

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