Research On Electromechanical Design And Aerodynamic Test Of Multi-Degree Of Freedom Bionic Aircraft

Since the ancient times,we human beings have never given up on the exploration of flight.Although,the fixed wing aircraft and rotorcraft,which are devised by human beings,are excellent enough,but their flight performance is still far from that of natural flying animals,especially of insects.Natural flying animals generally use the flapping wing to fly——they could have distinguished flight mobility by adjusting the movement of the wings.The flapping-wing flight of animals has always been a research focus of scientists.The research of flapping wing is helpful to the design of flapping-wing aircraft,especially to the micro aerial vehicle(MAV)in centimeter scale.Because in centimeter scale,conventional fixed-wing aircraft struggle to get enough aerodynamics to take off.But insects can fly by using flapping wings.So,it is necessary to explore the movement of flapping wings and their generation of aerodynamics.The research content of this article is to explore the design of flapping wing aircraft Furthermore,we also designed and built a platform for aerodynamic test of flapping wings.We tested the differences of aerodynamic performer between rigid wing and flexible wing and discussed one of the key issues still debated in flapping wing research——what role does the flexibility of insect wings play in generating aerodynamic force.The main research content of this subject including:1.Have introduced the research background,mainly including the concept of flapping wing micro aerial vehicle,the research progress of flapping wing aircraft at home and abroad,and the research background of flapping wing flexibility.2.Have reviewed the flight principle of insect flapping wings,compared the similarities and differences between the wings of birds and insects,compared the flight characteristics of flapping wings of birds and insects.Have concluded several common bionic flapping wing mechanisms and their principles.And then,according to the purpose of the experiment,we put forward the bionic flapping wing mechanism used in this experiment.This mechanism has a differential gear structure,which can realize the flapping and rotation.The motion of this mechanism is implemented by the cooperation of two servos.3.Have designed and manufactured two flapping wing aircraft with the above flapping wing mechanism as the core.Aiming at light weight and miniaturization,we designed and manufactured the first insect-like flapping wing micro aerial vehicle.The second aircraft was designed to imitate birds.At the same time,we designed the flapping wing of the aircraft to fold like bird wings.4.Combining the exploring experience of the above two aircraft,we developed a aerodynamic test platform for flapping wing.We used STM32 series chips as the control core,four servos to control two flapping wings and six component force sensors to collect aerodynamic data.The experimental process was designed based on the concept of hardware-in-the-Loop(Hi L): the flapping model generated the flapping motion data,the superior computer collected data for processing and generated new motion data,and then the motion data was loaded into the model for a new round of experiments.5.We successfully assembled the experimental test platform.Three different phase motion curves were designed in this experiment——advanced,symmetry and delay phase.Then,the aerodynamic comparison test between rigid and flexible wing had been done with the three different phase motion curves.By analyzing the experimental results,we conclude that the advanced phase of the rigid wing has the best aerodynamic performance.6.At last,we discussed the experiment,analyzing the deficiencies of the experiment and the following improvement.For instance,the design of the wing flexibility need to improve.To explore the influence law of flexibility change on aerodynamic force,more control trials are needed.