| The quadrotor unmanned aerial vehicle has gained popularity in military and civilian fields in recent years due to its advantages such as simple structure,high maneuverability and low production cost.However,because of the characteristics of non-linearity,strong coupling,multivariable and underactuated,the research difficulty is greatly increased.This thesis focuses on the controller design of quadrotor UAV based on QBall2 of UVS platform.The main contents of this research include the following aspects:1.Establishment of a mathematical model for QBall2 quadrotor UAV.The structural characteristics and flight mechanism of QBall2 were introduced.Based on the inertial coordinate system and the body coordinate system,the nonlinear mathematical of the quadrotor UAV was deduced.2.Integral backstepping sliding mode controller design.According to the semi-coupling characteristic of QBall2 quadrotor UAV,a double closed-loop control structure with the attitude loop as the inner loop and the position loop as the outer loop was designed.The controller was designed based on the nonlinear algorithm-backstepping method.Considering the existence of external environmental disturbance and system parameters perturbation in the flight process of the quadrotor UAV,the sliding mode control with strong anti-interference ability was integrated into it to enhance the robustness of the system.At the same time,the integration step was introduced to reduce the state error and adjustment time.Eventually,a backstepping sliding mode controller with an integral step was designed.Two sets of comparative simulation experiments verify that the integral backstepping sliding mode controller is superior to the backstepping controller and traditional backstepping sliding mode controller.3.Controller design based on ESO and integral backstepping sliding mode method.For the problems of strong compound disturbance and uncertainties in system modeling,the integral backstepping sliding mode controller cannot complete the accurately tracking task,adding an extended state observer(ESO).Eventually,a robust controller was designed based on ESO and integralbackstepping sliding mode algorithms.The total disturbance of the system was estimated in real-time through ESO and compensated in the control volume,thereby enhancing the system’s anti-jamming capability.Two sets of contrast simulation experiments with fixed-point hovering and trajectory tracking verify the effectiveness of the control strategy.4.Semi-physical verification based on UVS platform.The system composition of UVS platform was introduced and a semi-physical comparison simulation experiment based on it was completed.Strong anti-jamming capability of the controller was verified,and the tracking performance of position and attitude angles was analyzed. |
