Research On Wind Disturbance Resistance Of Quadrotor UAV

Quadcopter UAV has the advantages of simple structure,flexible maneuverability and strong applicability,and has been widely used in military and civilian fields.With the specialization of its purposes,users have increasing requirements for the performance of their controllers.This thesis mainly focuses on the control problem of quadrotor UAV interference in wind field,and the specific work content is as follows:(1)The mainstream X-type quadcopter UAV was selected as the research object,and its structure and basic flight principle were analyzed.The ground inertial coordinate system and the bulk coordinate system are established,and the transformation equations between them are derived.Based on the Newton-Euler equation,the dynamic model of quadcopter UAV is established,and then the dynamic model under special conditions is established by studying the influence of wind field and power system failure on quadcopter UAV.(2)Aiming at the problem of trajectory tracking deviation of quadrotor UAVs that are disturbed by wind fields below breeze(wind speed less than 5m/s)and have a single rotor fault,the position subsystem adopts a fractional PID controller,which is improved by feed-forward compensation and incomplete differentiation to suppress the disturbance of uncertain factors.The attitude subsystem designs a backstep adaptive sliding mode controller,which reduces the probability of sliding mode jitter and provides good adaptability and robustness.The simulation results show that the scheme can effectively ensure the trajectory tracking and attitude stability of the quadrotor UAV in the event of wind field interference and single-rotor failure.(3)Aiming at the control problem of quadrotor UAV under the interference of strong wind(wind speed between 8m/s-10.7m/s),this thesis designed an adaptive fractional-order terminal sliding mode controller for the position subsystem,which used the characteristics of fractional operators and adaptive law to suppress external interference;for the attitude subsystem of UAV,an adopted adaptive fractional terminal sliding mode controller based on nonlinear interference observer was designed,the method used the interference observer to observe the compensation control quantity to suppress interference and improve controller performance.Simulation results show that the scheme can effectively suppress the strong interference and has good control performance.