Mechanism Design And Dynamic Simulation Research On Bionics Flapping-wing Air Vehicles

Bionics flapping wing micro air vehicles are new conceptual air vehicles that mimic the flying modes of birds and insects. They have the advantages of small sizes, light weights, low costs, good stealth abilities and high maneuverability. They are widely used in the fields of military and civil application. The studies of bionics and aerodynamics indicate that the MAV which the characteristic dimension almost equate to bird or insect, the flapping flight mode is precede to be more efficient.Based on the comprehensive analysis of various common driving mechanism of flapping wing aircraft, both mathematics model and simulation model of single-crank-and-double-rocker are established. The curves of simulation results are consistent with the curves of corresponding mathematical models, which verify that both the mathematics model and simulation model are correct. In order to enhance the movement symmetry of the single-crank-and-double-rocker driving mechanism, the comprehensive estimate function is constructed based on the mathematics models of the margins of the flapping-angle and the margins of angular speed and an optimization is then carried on to the comprehensive estimate function under the restraint conditions of mechanics and bionics. The results of the optimization are helpful to both the same kinds of driving mechanisms and the other kinds of driving mechanisms.On the foundation of animal flight scaling rule, main structure parameters of flapping wing aircraft are calculated referring to the bionic design formulas using quality as basic parameters. A three-dimensional machine model is established and its driven system and aerodynamic layout including wing structure and tail structure are designed in detail.Based on the biological principles of birds and insects flapping flight, the aerodynamic characteristics of biomimetic wing are numerical simulated using CFD method and the effect of the up-and-down movement and its joint movement with the pitching motion on the aerodynamic characteristics is analyzed. According to the mechanism of aerodynamic, the aerodynamic lift during the process of flapping flight was calculated using numerical simulation results combined with the actual parameters of biomimetic wings.The simulation model of flapping wing aircraft is then established in ADAMS,and the calculated results of the aerodynamic lift are applied to the wing. The dynamic state of the prototype is simulated and the force condition of the key points are analyzed. The present study provides the foundation of prototype designing and manufacturing in the future.