Modeling and linear control of a flapping-wing MAV with split-amplitude and phase-modulated wingbeat

In this paper we propose a new wingbeat control strategy with split amplitudes and phase shifting for a six-degree-of-freedom flapping-wing micro air vehicle (MAV) model. Implementation of the amplitude and phase modulation is discussed, and cycle-averaged forces and moments and cycle-averaged control derivatives are computed to derive nonlinear and linear control design models (CDMs) of the MAV. The proposed wingbeat control strategy is capable of generating non-zero cycle-averaged longitudinal and vertical forces, and non-zero cycle-averaged rolling, pitching, and yawing moments. A thorough analysis of all possible output candidates is done based on the existence of vector relative degree and characteristics of the internal dynamics of the linear CDM. Finally, a controller is designed based on the normal form of the linear CDM resulting from the selected outputs. The controller is tested on a higher-fidelity instantaneous blade-element model, where parametric uncertainties are also taken into consideration.