Bionic design and attitude control measurement in a double flapping-wing micro air vehicle

The interest in flapping-wing Micro Air Vehicles (MAVs) has been rising progressively in the past years, as they can combine high agility manoeuvres with precision hovering flight and can be applied in complex spaces for reconnaissance missions. In this study, we propose a double flapping-wing MAV, which has four wings comprised by two pairs, each pair is driven by one brush motor and one linear servo. The flapping mechanism is composed of a crank-rocker and double rocker mechanism, which can amplify the output angle of wings and used for lift increasing. We take the Rhinoceros beetle as a bionic object and the Weis-Fogh mechanism as the high lift generation principle. The vehicle can actively control 4 degrees of freedom (DOFs), namely, roll, pitch, yaw, and thrust. Compare to the single pair counterpart, our vehicle possess a high thrust-to-weight ratio, which make it possible for more onboard load and beneficial to attitude control, additionally, the 3 rotational DOFs (roll, pitch, and yaw) is completely uncoupled and controlled independently, which is useful for control system design. The currently vehicle weighting 32.8 g (without the battery) and can generate 0.34N thrust at the maximum flapping frequency of approximately 23 Hz.