Abstract: Hovering ability forms the basis for space operations of Micro Aerial Vehicles (MAVs). The problem of uneven load puts high demands on the wing design. In this paper, a new hovering-mode for MAVs, inspired by flapping flight in bees and hummingbirds but using high-aspect-ratio and low-stress wings, is proposed. Different from the flapping actuations that occur at the wing roots, the two wings are driven back and forth in a straight line. To simplify the design and control the angle of attack, passive wing rotation is employed. The numerical results and analysis show that the maximum stress of the oscillating wing is approximately 1/6 of that of the flapping wing when the lift of the oscillating wing is twice that of the flapping wing. A theoretical aerodynamic model of the kinematics of the vehicle’s driving mechanism was developed to fulfill its design. Force measurements indicate that the vehicle generates a sufficiently high cycle-averaged vertical thrust (71 g) for liftoff at a maximum frequency of 5.56 Hz, thereby validating the proposed aerodynamic model. Moreover, liftoff performance is presented to visually demonstrate the vertical take-off capabilities and hovering potential of the aeromechanical solution.

Key words: bioinspired, oscillating-wing, high aspect ratio, low-stress wings, micro aerial vehicles, vertical take-off and hovering