Design Of Multi-DOF Flapping-Wing Micro-Air Viecle

Because MAV (Micro Air Vehicle) has an extremely widespread application prospect in the military and the civil fields, it becomes a hot research spot at home and abroad. Compared to the fixed-wing and the rotary-wing MAV, flapping-wing MAV has superiority, flapping-wing MAV will certainly occupy important position in this research field and have great significance to develop aerial technology.This paper studies some related design questions about flapping-wing MAV. the main work is as follows:Firstly, embarking from the structure of insect and bird wing, this paper analyzed the flight mode, the flight theory and the flapping-wing motion pattern of two kind of flights biology. The basis of theory and bionics are provided for the flapping-wing MAV's design.Secondly, the structural properties and the design constraint of flapping-wing mechanism are induced according to the mechanism including six links seven kinematic pairs. Applying kinematic chain transform theory, the new pattern flapping-wing mechanisms are evolved. This provides the important reference for flapping-wing MAV's design. Based on the wing motion of insects, a multi-DOF(multi-degrees of freedom) mechanism with complex of tree-type motion for the insect-like flapping wing is proposed. Due to the tips of wings can trace a figure-of-eight or banana, and two wings can twist, the wing motion is in much more accord with the pattern of wing motion for insects. A parameter optimization model of the mechanism is established to realize the motion track of biology.Thirdly, in the motion of flapping-wing system, due to variety of the inertia and aerodynamic moment, the motion of the input link has speed fluctuation, affecting the mechanical efficiency and aerodynamic performance. Based on Lagrange's equation, the dynamic equation of a single-DOF and Multi-DOF flapping-wing mechanism was established and the actual motion was studied. The major effect factor is the rotational inertia of flapping-wing. The system movement is steady by flywheel. The torsional spring enhances the efficiency of flapping-wing transmission system and the flapping-wing lift.Fourthly, the flow fielsd of flapping-wing with three kind of compound motions were computated. The flapping-wing with compound motion can produce higher lift and thrust. The influence motion parameters for the lift and thrust of flapping-wing is the plunging amplitude and frequency, next is the sliding amplitude and pitching mean angle, last is the pitching amplitude. The increases of pitching mean angle reduces the thrust.Using multi-DOF flapping-wing MAV, the load measurement experiment was done in low-speed wind tunnel. The lift and drag were measured with different flapping frequency, attack angle and free-stream velocity. The MAV's aerodynamic characteristic was studied.