Development and Testing of the Mentor Flapping-Wing Micro Air Vehicle

In 1997 the Defense Advanced Research Projects Agency initiated a program to explore the possibility of micro air vehicles for the purpose of individually portable surveillance systems for close-range operations. The various contractors approached the problem in several ways, such as developing tiny fixed-wing airplanes, rotary-wing aircraft, and ornithopters mimicking animal flight This paper describes one such flapping-wing aircraft, which drew upon the clap-fling phenomenon that is exploited by many flying animals and insects for lift generation. Essentially this aircraft was a mechanical simulation of hummingbird flight, though with two sets of wings to eliminate the unbalanced side-to-side flapping forces. Two flying demonstration models were built, one with an internal-combustion engine and another with an electric motor. In both cases, these incorporated a drive train to reduce the high rpm rotary shaft motion to lower-frequency oscillation for flapping. Also required was a programmable logic board for stabilization. Successful hovering flight was achieved with both models, and initial studies of transition to horizontal flight were also explored.