Research On The Wind Resistant Performance Of Four-Rotor Unmanned Aerial Vehicle Based On Auto Disturbances Rejection Algorithm

Four-rotor unmanned aerial vehicle(UAV)is a aircraft that can vertical take off and landing,autonomous hover and low-speed flight,it compares to fixed-wing aircraft has a strong mobility.The wind resistance is one of the most important factors that affect the stability of the four-rotor UAV's control system.However,due to the complexity of the fuselage's dynamic equation of the four-rotor UAV,it is susceptible to external gust and internal noise,so it is difficult to build an accurately model for four-rotor UAV.In this paper,X450 four-rotor UAV is used for the research's platform,based on the auto disturbance rejection control(ADRC)to build and simulate the model and study on the wind resistance of gusts and continuous winds in different situations.In this paper,firstly,build the fuselage's dynamics model of X450 four-rotor UAV,use New-Euler equation,fuselage's coordinated system and inertial coordinated system to analyze the mechanical properties,analyze the effect rotor affects UAV by air force during flight,reasonable linearization under appropriate assumptions,acquire the fuselage's dynamics equations and the UAV's attitude and positional motive equations.According to the characteristics of the four-rotor UAV's dynamic model,the ADRC is adopted to design the inner-loop attitude-controller,and the outer-loop positional control algorithm uses PID.The result of the simulation shows that the ADRC can compensate for the internal disturbances and external disturbances and effectively improve the robustness of the system.Under the different wind level to analyze the attitude-angle's mutative curve of four-rotor UAV that based on ADRC controller,by comparing the overshoot,adjusting time and steady-state error of the control system under different disturbances,it is concluded that the ADRC can improve the wind resistance of the system.Finally,the actual flight's test of X450 four-rotor UAV is carried out.The flight test and data acquisition are carried out in the gusty wind and continuous wind environment.Through the comparison and analysis of the collected d ata,it is proved that the attitude-controller based on ADRC can improve the wind resistance of four-rotor UAV effectively.