Design and kinematic analysis of flapping wing mechanism for common swift inspired micro aerial vehicle

The article presents a novel flapping wing mechanism for Micro Aerial Vehicle (MAV) inspired by one of the most efficient flyers of the aerial world, the Common swift ( Apus apus). The flight characteristics such as wing beat frequency, wing beat amplitude, and fore and aft movements, as well as wing rotation of the bird at a flight speed 8 m /s, were studied. The common swift rotates its hand wing keeping the pitch of the arm wing constant during the entire wingbeat cycle. The hand wing undergoes forward rotation during the downstroke and backward rotation during the upstroke. This complex wing kinematics enables swift to generate various unsteady aerodynamic mechanisms. Using the geometric and kinematic details, a flapping wing mechanism that emulates the wing kinematics of the bird was designed. The flapping wing mechanism based on the epicyclic ellipsograph mechanism presented herein integrates flapping motion, fore and aft motion, and selective wing rotation. Importantly, this fully constrained mechanism allows performing all the key kinematic motions of the common swift with a single actuator. A kinematic model of the mechanism is presented to calculate the design parameters based on the scale of the MAV. Kinematic simulation of the mechanism is also presented to verify the design.