Research And Application Of Incremental Control For Quadrotor UAV To Reject Disturbance

Quadrotors have been widely used in many industries due to their advantages such as high flexibility,wide adaptability and low cost.At the same time,the special applications have made the influencing factors such as external interference more and more complex.In order to improve the anti-interference ability of the quadrotor,the theoretical research and practical test in attitude estimation and attitude control are carried out respectively.The main research contents are as follows:Firstly,a fast extended Kalman attitude estimation method is designed which can compensate the gyro bias.The fast and accurate attitude estimation is an important prerequisite for attitude control of UAV.In order to overcome the influence of sensor measurement noise and drift,and improve the speed of attitude estimation,a fast extended Kalman attitude estimation method based on the quaternion is designed by using gyroscope,accelerometer and magnetometer.Practical tests show that this method can provide stable and reliable attitude information of quadrotors.Then,considering that the stable attitude control of the quadrotor is the key to its stable flight,this thesis conducts the research on the anti-jamming control of the quadrotor attitude based on active disturbance rejection control,incremental control,and adaptive sliding mode control.The core of active disturbance rejection control is to estimate and compensate the total interference by useing the extended state observer.Since the internal coupling of the quadrotor attitude model is known,a cascade-structured quadrotor attitude auto-disturbance rejection controller is designed which uses both the known model and the disturbance estimation to compensate the control variable,and numerical analyzes are performed in the simulation environment.As a sensor-based control method,the incremental control suppresses unknown disturbance by using the feedback of control variables and the differential of system states.In this thesis,quadrotor attitude controllers are designed using incremental nonlinear dynamic inversion and incremental backstepping methods,respectively,and stability proofs are theoretically verified.The effectiveness of the incremental control scheme against external interference is analyzed by simulation.When the angular acceleration of the vehicle cannot be measured directly,the extended state observer is used to estimate the angular acceleration,so it can expand the application range of incremental control.Adaptive sliding mode control is a kind of variable structure control method that can automatically adjust the sliding mode control gain,which has the characteristics of small control chattering and strong robustness to unknown disturbance.Based on a new dual-layer adaptive strategy,three control schemes are designed,namely,adaptive sliding mode control,adaptive sliding mode observer control,and incremental adaptive sliding mode control.The simulation results show that the incremental adaptive sliding mode control can significantly mitigate the chattering of the sliding mode control gain,and can overcome the influences of external disturbance and actuator failure.The attitude incremental adaptive sliding mode control scheme is tested on the actual quadrotor,which shows that this method can improve the anti-interference ability of the quadrotor,and has practical application value of the quadrotor attitude control.Finally,the above research content and research significance are summarized in this thsis.By appropriately modifying the above advanced control methods and applying them to the attitude control of the quadrotor,it provides guidance for the application of the control algorithm in the actual control of the quadrotor,and the actual flight test shows that the incremental control scheme can be widely used in the control field of the quadrotor UAV.