Driving Structure Design and Analysis of Multi- DOF Bionic Flapping Wing Aircraft

In order to improve the flight performance of flapping-wing aircraft, a new multi-degree-of-freedom bionic flapping-wing driving mechanism is designed based on the flight motion characteristics of gulls: The dual-crank and dual-rocker mechanism is used as the driving mechanism, and the two- segment wing structure is used as the wing to realize the expansion and folding function of the wing. The planar double crank rocker mechanism and spatial crank rocker mechanism are coupled through bevel gears so that the aileron can twist during wing flapping. The whole moving process is only driven by a DC brushless motor with a simple structure and high flight efficiency. Firstly, the kinematic model of flapping-wing vehicle driving mechanism is established through kinematic analysis. Then, the simulation analysis model of the flapping-wing mechanism is established in ADAMS simulation software, which verifies the theoretical analysis. The results show that the designed driving mechanism can realize multi-degree-of- freedom coupling motion of flapping, torsion, and folding by single-degree-of-freedom driving. The upper flapping limit is 22.6°, the lower flapping limit is -21.5°, the maximum torsion angle is 10.5°, the minimum torsion angle is -16.6°, and the folding angle range is 144.7°~192.1°. The output trajectory is the same as the wingtip trajectory of the seagull when flying and has good aerodynamic performance. The kinematic parameters obtained from the simulation are consistent with the theoretical calculation, which verifies the correctness of the theoretical calculation.