Flight Control Technology And Realization Of Small Unmanned Aerial Vehicle With Hanging Load

Four rotor UAV suspension transportation system is an important way to realize the air transportation of materials based on four rotor aircraft.It can realize the rapid transportation and distribution of materials in complex and dangerous environment.Due to the external interference,system uncertainty and the underactuated characteristics of the four rotor UAV system,it poses a great challenge to the flight control of the system.Therefore,a binocular camera design load position information acquisition scheme is proposed in this paper.The expected flight trajectory of four rotors under suspended load is planned by using differential flattening technology,and a four rotor underactuated scheme based on sliding mode control concept is proposed.The design method of the subsystem and the complete drive subsystem controller enables the four rotor aircraft to track the desired flight trajectory and ensure that the swing angle of the suspended load gradually converges to the desired angle.The main work completed in this paper includes the following three aspects:(1)Starting from establish transformation relations by given transformation matrices between reference systems,and then the force analysis of the entire quad-rotor load suspension flight system is carried out by Newton's second law,which is generally applicable in engineering Under the circumstance,general assumptions are made at the same time,and on this basis,the Euler-Lagrange method is used to model the hanging load model.Thus,a dynamic model of the four-rotor load suspension that can describe the system in detail and relatively accurately is gradually deduced.(2)Aiming at the partial state uncertainty in the dynamics model of the quadrotor load suspension flight system,a load position capture algorithm for binocular camera based on parallax principle is designed.Through binocular camera calibration,the relative transformation matrix and internal and external parameters of the binocular camera are obtained.According to the parallax principle,the depth information of the load relative to the object is calculated,and the position information of the suspended load is calculated based on this.Finally,according to the Kalman filter technology,Forecast and estimate load locations to smooth data.(3)Based on the suspension load dynamics model of the quad-rotor UAV,it is divided into a full-drive control subsystem and an under-drive control subsystem.Based on the theory of differential flattening,a robust control method for quadrotor UAV based on sliding mode control strategy is proposed,and the stability of the designed control system is strictly analyzed using the second method of Lyapunov.Finally,a flight experiment platform was designed,the effectiveness of the plan was verified through flight experiments,and the experimental results were analyzed.