Aerodynamic Theory Research And Structural Optimized Design Of A Bat-like Flapping Wing Micro Aerial Vehicle

Micro flapping-wing aerial vehicle imitates the flapping-wing flight of insects,birds and bats.It has low noise,good concealment,high maneuverability,and low contact injury.Most of the existing micro flapping-wing aerial vehicles are insect-like and birdlike aircrafts,and there are few bat-like aerial vehicles.Existing bat-like aerial vehicles can realize the expansion and expansion of wings,but they still cannot reach many superb flying abilities of bats,and further research and improvement are needed.Based on the aerodynamic theory research of the bat-like micro flapping wing aircraft,this paper completed the structural optimization design and prototype development,mainly including the following contents:Firstly,the morphological characteristics of the biological bat and the kinematics during flight are studied,and the guiding and enlightening information is obtained from them.Considering the flight performance,feasibility and overall quality,the bat structure is reasonably simplified to complete the overall design of the bat-like aircraft structure,including the forearm active deformation mechanism,the leg active deformation mechanism and the wing flapping mechanism And the fuselage,determine the layout of the freedom of the whole machine.According to the quasi-steady aerodynamic theory and the strip theory,the Zhukovsky lift and comprehensive drag calculations of the bat-like wing are completed to obtain the key shape parameters of the wing surface.Combined with the aerodynamic calculation theory,the average lift when flying at a constant speed As the goal,based on MATLAB optimization toolbox,the optimized design of wing size and shape and skeleton layout was completed.The inside wing uses a high elasticity silicone film to adapt to the expansion and deformation of the forelimbs,and the outside wing uses a high-rigidity kite cloth to increase the lifting thrust.The optimized design of the forelimb active deformation mechanism,flapping mechanism and leg active deformation mechanism of the flapping wing aircraft was completed.The forelimb active deformation mechanism is based on Watt’s six-link,using a miniature screw nut pair deceleration transmission,the kinematics of the forelimb link is analyzed,and the multi-objective size optimization design is completed.Based on the Solid Works Simulation finite element plug-in,the calculation of the non-linear tensile force of the wing membrane deformation and the strength check of the forearm connecting rod are performed.The parameter calculation of the screw nut pair with the axial and radial loads is carried out.The flapping mechanism is based on the space crank and rocker mechanism,using two-stage gear reduction transmission,given two flapping laws of equal amplitude and unequal amplitude,and optimizing the size of the design,calculating the flapping power of the two wings and finite element bending strength of the reduction gear Check.The active leg deformation mechanism is based on a four-bar linkage.Through the kinematic analysis and multi-objective size optimization of the two working forms of the linkage,a relatively compact leg mechanism is obtained.The development of two generations of prototypes was completed.The firstgeneration prototypes used six-dimensional force/torque sensors to perform aerodynamic measurement experiments,and obtained the lift thrust curve without free flow.In order to improve the design of the problems of the first-generation prototype,the secondgeneration prototype was developed,and the suspension and non-suspension free flight experiments were carried out.The prototype can fly smoothly,and further lift is needed to achieve long-distance free flight.