Dependence of Flight Performance of Flapping UAV on Airframe Size

Abstract

We investigated the relationship between flight performance and size of a X-wing type flapping UAV. The flapping UAV equipped with a double motor drive system to control the flapping frequencies of left and right wings independently. UAVs of various sizes with different fuselage lengths, wing spans, and tail lengths were fabricated, and their lift and mobility were measured. The gearbox structure driving the flapping wings was modified to fit a variety of aircraft sizes. The lift force decreased as the aircraft size decreases. Furthermore, the lift force was largely dependent on the wing span, and there is an optimal span. On the other hand, mobility was found to increase with decreasing aircraft size.