Longitudinal Flight Dynamics of Flapping-Wing Micro Air Vehicles

The multibody flight dynamics of flapping-wing micro air vehicles are inherently complex. Stability analyses and control algorithms are best applied to equations of motion in first-order form. This paper presents a method for approximating the first-order equations of motion for a flapping-wingmicro air vehicle. The first-order equations of motion are derived from a coupled, multibody representation of the system. The first-order equations are analyzed using an approximation method called quarter-cycle averaging. The quarter-cycle averaging method is necessary because the classical averaging techniques are not available. The quarter-cycle approximation method is applied to representations of hovering flight and forward flight. The method enables the calculation of equilibrium points for the averaged system.Forbothflight regimes, the quarter-cycle approximatiomethodprovides anorder ofmagnitude improvement in accuracy when compared to local averaging.