Research On Flight Controller Of Ornithopter Based On Double Crank Structure

Flapping wing flight is a kind of flight mode formed by birds and insects after long evolution.Bionic ornithopter is a kind of flapping flight mode of birds or insects,mainly through the flapping wings to obtain lift and thrust aircraft.In recent years,as unmanned aerial vehicles have been widely used in many fields such as reconnaissance and search and rescue,bionic ornithopter has gradually entered the field of vision of researchers and become a research hotspot due to its advantages such as strong maneuverability,high energy utilization efficiency and good camouflage.In addition to the up-and-down flapping of the wings,large birds also spread their wings when flapping under the wings to increase the windward area and obtain greater lift.In addition,large birds fold their wings when flapping on the wings to reduce the resistance of the windward area.In order to imitate the flapping mode of large birds,a bionic flight controller of ornithopter is designed in this paper.In this paper,a new flapping mechanism is designed to realize the active expansion and folding of the wing while flapping.Secondly,the fixed altitude flight control algorithm of bionic ornithopter flight controller is proposed.Thirdly,the bionic ornithopter flight controller system is designed.Finally,the performance of the controller is simulated and analyzed.In order to solve the problem of insufficient stability and weak adaptability of traditional PID flight controller in the face of complex flight attitude of the flapping wing and changeable air flow conditions,this paper designed a fuzzy adaptive PID flight controller to control the bionic flapping wing aircraft to achieve fixed altitude flight,and to have better stability and adaptability when the air flow conditions change.The specific research content of this paper is as follows:(1)By studying the flight mechanism and scale law of large birds,this paper designs the bionic flapping wing double-layer crank mechanism,and puts forward the action planning for this mechanism.A new type of double-layer crank flapping mechanism is designed in this paper.The design process is described in detail,the complex vector method is used to analyze it,the size of each connecting rod is calculated according to the size parameters,and the kinematic equation of the wing flutter is calculated.(2)This paper designs a fuzzy adaptive PID flight controller based on fuzzy logic algorithm to control the designed bionic ornithopter to fly at fixed altitude.In this paper,the kinematic model of bionic ornithopter flying is constructed,and the system structure of fuzzy adaptive PID flight controller is introduced in detail.The implementation process and the design of correlative functions,rules and parameters of the fuzzy adaptive PID flight controller designed in this paper are described in detail.(3)The control system of bionic ornithopter flight controller is designed in this paper,and the overall design scheme of bionic ornithopter flight controller hardware system,software system and fuzzy adaptive PID flight controller software control flow are proposed.The design process of STM32F103VET6 main controller and its external steering gear and drive module,pressure gauge module,2.4G communication module,brushless DC motor and drive circuit,isolation circuit and voltage conversion circuit is introduced in detail.(4)The performance of flight controller of bionic ornithopter is verified by simulation in this paper.Firstly,the kinematic planning of double-layer crank flapping mechanism is verified by using Adams software.Secondly,the performance of the fuzzy adaptive PID flight controller designed in this paper is simulated and compared with the traditional PID flight controller by Simulink.Finally,the flight performance of the designed bionic ornithopter is simulated and verified by using fluid dynamics simulation software.