Research On Anti-wind Disturbance Control Of Quadrotor UAV In Complex Environment

With the development of UAV technology,the application scenarios of drones are gradually increasing.In some environments,such as plateaus,seas,canyons and other complex environments,there are often high-speed and violently changing wind fields,and the anti-wind disturbance performance of UAVs in these complex environments has become a difficult point.How to make UAVs achieve stable attitude control in these complex environments with strong wind fields is of great significance.The research of this thesis is oriented to the wind resistance control of quadrotor UAVs in complex environments.By studying the changes in the drag coefficient of quadrotor UAVs in different attitudes,a more accurate dynamic model is obtained,and a wind-disturbed windless control system is designed.The man-machine attitude control algorithm realizes the stable control of UAV attitude under 6-level(10.8～13.9m/ s)gradual wind and gust disturbance in the simulation,and realizes the stable control of 5-level gradual wind and gust disturbance under the flight test environment.In view of the above problems,the main research work of this thesis is as follows:1.The construction of the dynamic model of the quadrotor UAV under the disturbance of the wind field is realized.According to the difference of the drag coefficient of the quadrotor UAV in different attitudes,the geometric model of the UAV was built and meshed,and the aerodynamic simulation was carried out for the resistance of the UAV in different attitudes.Finally,the function of the drag coefficient changing with the attitude of the UAV is obtained.The wind field disturbance factor is introduced according to the drag coefficient to obtain a more accurate dynamic model.This research content provides a more accurate dynamic model for the follow-up UAV wind resistance control simulation in the wind field.2.A wind-resistant attitude controller for a quadrotor UAV is designed and implemented.According to the characteristics of the disturbance of the quadrotor UAV in a complex environment,such as drastic changes,firstly,a Linear Active Disturbance Rejection Controller(LADRC)was designed and parameters were adjusted,and a set of parameters with better effect was obtained,which provided initial values for the fuzzy self-adaptation of subsequent parameters.Secondly,due to the uncertain change of wind disturbance,fixed parameters cannot be applied to all situations,so the ambiguity rate is designed according to the characteristics of each parameter,and the parameters of LADRC are adaptively adjusted.Finally,the attitude control of the quadrotor UAV is carried out by using the Fuzzy-Linear Active Disturbance Rejection Controller(FuzzyLADRC),and the stability is proved.In the simulation environment,the attitude control effect of 5-level gradual wind and gust disturbance is studied,and the stable control of the attitude of the quadrotor UAV under 6-level gradual wind and gust disturbance is realized.3.Design and realize the test flight verification platform of the wind resistance control system of the quadrotor UAV,including the gradual wind and gust environment and the test UAV.The stability control of the attitude of the quadrotor UAV in the 5-level(8.0～10.8m/ s)gradual wind and gust environment is verified,and compared with the simulation,the effectiveness of the control algorithm and the accuracy of the dynamic modeling are further verified.