The Research On Driving Mechanism Of Flapping-wing Air Vehicle

It is generally recognized that flapping-wing air vehicle (FAV) has advantage over fixed-wing aircraft and rotary aircraft in maneuverability and lift-to-drag ratio. For the present study of driving mechanism of flapping-wing air vehicle, gear transmission and four-bar mechanism was used to realize "8" shaped trajectory of wing. What’s more, flapping-wing air vehicle can complete forward, turning and lifting movements combining with the adjustment of tail. But when the air vehicle meets special conditions need to observe carefully, it should have the ability to hover and retreat in the process of unmanned rescue and accident scene survey. This is also the starting point for research, to study a driving mechanism that make the flapping-wing air vehicle hover and retreat.By analyzing the various drive modes, transmission mechanism and wing’s category of flapping-wing air vehicle, the design basics of driving mechanism have been confirmed. Flight characteristics and mechanism of birds and insects have been studied. And then, wingspan, wing’s area, wingbeat frequency and other parameters have been calculated according to the biomimetic formulas. The motor which implements wing’s flapping has been chosen and drive system has been designed through wingbeat frequency. The model of flapping-wing air vehicle’s wing has been established based CFD(Computational Fluid Dynamics), and then aerodynamic simulation analysis was carried out on the wing.In the process of the design of wing’s twisted structure, the "8" shaped motion mechanism has been analyzed. And combining with the disadvantages of them a mechanism has been raised that can achieve wing’s twisting motion. A rod mechanism, that can adjust the trailing of wing, is designed from the reference of crank-rocker mechanism. A turn-able lever mechanism, that can make the leading edge of wing rotational, is designed from the reference of chute structure. Analytical method is used to position analysis of mechanism. Pro/E is used to simulate and verify the twisting mechanism. MATLAB is applied to optimize the twisting mechanism. At last, the control system of traditional flapping-wing air vehicle have been studied, flight strategy and motion control have been researched from two aspects of artificial control and autonomous control, and the structure diagram of control system has been given. Wing can be twisted, angle of attack can be changed, and the hover and reverse motion can be achieved by adjusting the rocker’s angle of twist mechanism.