Difficulty of Controlling a Flapping-wing Aircraft Compared to a Rotary-wing Aircraft

Abstract

The inherent stability of two-dimensional motion when hovering using beating wings that have a passive feathering motion is compared with that of rotary wings that have a passive flapping motion. The passive flapping motion of the rotary wings is determined by the bending elasticity, which is expressed by a spring at the wing root. The feathering motion of the beating wings is determined by the torsional elasticity, which is expressed by a damper and a spring at the wing root. The values of the damper and spring were determined by minimizing the necessary power in the present analysis. Unlike rotary wings with passive flapping motion, beating wings with passive feathering motion do not have pitch/roll damping. A flying robot with beating wings requires quicker flight control than one with rotary wings. The results indicate that a flying robot mimicking a living creature is more difficult to control than one with rotary wings.