Study On Attitude Control Method Of Bio-inspired Flapping Wing Micro Aerial Vehicles

Flapping Wing Micro Aerial Vehicles(FWMAVs)is a hot topic for the development of micro air vehicles at present and in the future.It can generate lift and forward force simultaneously by the motion of two wings,which greatly simplifies the structure of the aircraft,and has small size,and good concealment.Attitude control is an important part of the research of FWMAVs.It not only affects the maneuverability of the aircraft,but also is the basis for the aircraft to achieve obstacle avoidance,navigation,trajectory planning and other functions.Therefore,this paper studies the control method of the attitude of FWMAVs.The main contents are as follows.(1)The flight mechanism of FWMAVs is very similar to that of insects.Therefore,the mechanism of high lift force of insects is explained in detail first,including ClapFling mechanism,delayed stall mechanism,rotating circulation effect,wake capture effect and additional mass effect.The appropriate coordinate system is indispensable in the dynamic modeling of the aircraft.Therefore,the coordinate system commonly used in the dynamic modeling of FWMAVs is established,and the conversion relationship between each coordinate system is derived.(2)The FWMAVs is mainly subjected to three forces during its flight,its own gravity,the aerodynamic force generated by the wings and the air damping force.The self-gravity of the aircraft does not produce a moment,and the air damping force and the wing aerodynamic force produce a moment on the center of mass of the body.Therefore,the aerodynamic and aerodynamic moments,the body damping force and the damping torque of the existing flapping wing aircraft are summarized and studied.The attitude dynamics model of the flapping wing micro aircraft is established and a general mathematical description form is given.(3)A double closed-loop integral sliding mode adaptive control method is studied.In the inner loop control,the adaptive integral sliding mode method is used to design the controller,and the adaptive law of sliding mode gain is designed.The sliding mode gain can be adaptively changed without making assumptions about the upper bounds of uncertainties such as parameter perturbations,external disturbances,and unmodeled dynamics presented in the model.The simulation model is built in the MATALB/Simulink environment and the controller is verified by simulation.(4)A robust backstepping controller based on nonlinear disturbance observer is studied.Uncertainties such as parameter perturbation,external disturbance and unmodeled dynamics are separated from the system.The backstepping method is used to control the nominal system,and then the nonlinear disturbance observer is used to observe the interference and uncertainty in the system,and the system is compensated and controlled.The simulation model is built in the MATALB/Simulink environment and the controller is verified by simulation.