Tiny Nano Air Vehicle (NAV) to help in in-door surveillance
California company develops tiny UAV (10 gram, a 7.5-centimeter wingspan) that hovers and climbs with flapping wings; the NAV can explore caves and other hiding places, relaying GPS data and images to base
Small is beautiful. The smallest ever free-flying aircraft to hover and climb with flapping wings has taken off at aerospace firm Aerovironment of Monrovia, California. Until now such robots have not carried their own batteries and have been guided by wires that allow them to move only up and down. Aeronvironment has released video that shows its “nano air vehicle” (NAV), which is the size of a small bird or large insect, hovering indoors without such crutches and under radio control. “It is capable of climbing and descending vertically, flying sideways left and right, as well as forward and backward, under remote control,” says the company.
The Pentagon’s Defense Advanced Projects Research Agency (DARPA)commissioned the flying bug in 2007 and has rewarded the firm’s success with a further development grant (see 2 July 2009 HSNW). It wants a version rugged enough to cope with wind and the other challenges of flying outdoors.
As the Wright brothers demonstrated with the first powered aircraft in 1903, getting off the ground is just the first step to successful flight: controlling a flying machine in three dimensions is a significant challenge.
Paul Marks writes that Aerovironment’s flapper appears to achieve propulsion, stabilization and control all at once using its paired wings. Details of the technology are confidential, however, under the U.S. ITAR arms control export restrictions.
DARPA has said it wants a 10-gram aircraft with a 7.5-centimeter wingspan that can explore caves and other hiding places, relaying GPS data and images to base. It will need to fly at 10 meters per second and withstand 2.5-meter-per-second gusts of wind.
That goal is a long way off, but DARPA program manager Todd Hylton says Aerovironment is on the right track. “Progress to date puts us on the path to such a vehicle,” he says. Biopropulsion researcher Michele Milano at Arizona State University in Tempe agrees that the hovering bug is a breakthrough.
But he adds that Aeronvironment faces two big challenges: boosting maneuverability and energy efficiency. “Achieving maneuvering capabilities similar to those of hummingbirds or fruit flies will be tough. For that, a deeper knowledge and understanding of the aerodynamics of unsteady flapping flight is needed.”
The NAV’s endurance will also need to be upgraded. At present it can’t manage more than 20 seconds aloft.
