Design Overview of a Resonant Wing Actuation Mechanism for Application in Flapping Wing MAVs

This paper shows the design and analysis of the actuation mechanism for a four winged flapping wing MAV. The design is set up to exploit resonant properties, as exhibited by flying insects, to reduce the energy expenditure and to provide amplitude amplification. In order to achieve resonance a significantly flexible structure has to be incorporated into the design. The elastic structure used for the body of the MAV is a ring type structure. The ring is coupled to the wings by a compliant amplification mechanism which transforms and amplifies the ring deflection into the large wing root rotation. After initial sizing, the structures are analyzed by finite elements (eigenvalue and transient analysis). Based on the initial analysis, the structures are realized to be tested later. The wings are first analyzed independent of the structure in order to tune wing hinge stiffness to efficiently generate lift, exploiting passive wing pitching. The wings are tuned by using a quasi-steady aerodynamic model. The tuned wings are tested to judge if manufactured wings reflect the predicted performance. The ring-shaped thorax structure is combined with the wings to test resonant performance of the assembled structure. A test setup is built to quantify lift production. Lift is tested by suspending the prototype on a flexible beam and measuring changes in deflection when the model is actuated. Significant lift is produced using the current prototype. Kinematic patterns present during resonant actuation show correct timing of wing rotation.