Research On Quadrotor UAV Based On Cascade Active Disturbance Rejection Control

With the development of information technology,the quadrotor UAV occupies the majority of UAV market share due to the advantages of easy operation,portability and vertical take-off.Quadrotor UAV has an overwhelming advantage over other types of UAVs as fixed-wing UAV can not hover at fixed point and take off vertically while single rotor helicopter can take off vertically,but its tail rotor structure makes its operation difficult to soar,and its mechanical structure is more complex,so it is difficult to establish accurate mathematical model.At present,the flight control of quadrotor UAV has become a hot issue in recent years.The selection of control algorithm and the design of hardware and software system are the key to complete the flight control system of quadrotor UAV.Based on the ADRC algorithm,this paper analyzes the mathematical model of the quadrotor UAV,completes the design of ADRC and the cascade ADRC,carries out hover control simulation and independently builds the quadrotor UAV platform,and verifies the performance of the two controllers.The main work of this paper is as follows:1.The mathematical model of the quadrotor UAV is built,and the flight principle and the model of the quadrotor UAV are described.Firstly,the representation of Euler angle and quaternion is introduced,then the transformation formula of quaternion to Euler angle is deduced,and then the mathematical model of quadrotor UAV is established based on quaternion-Eulerian equation and Newtonian kinematics equation.In this paper,ADRC algorithm is used to design ADRC for hovering control.Then,based on the nonlinear and strong coupling characteristics of the quadrotor UAV system,the system is decoupled into two loops,namely,the attitude inner loop and the position outer loop,and the cascade ADRC is designed for hovering control.Finally,in the MATLAB/Simulink environment,the simulation experiments of the quadrotor UAV system with the above two controllers are completed,and the effectiveness of the controller design is verified.2.The hardware platform of quadrotor UAV is built and the control software is designed.The hardware platform includes the main control module,attitude sensor module,air pressure sensor module,optical flow sensor module,motor driver module and power module.The PCB design is completed,and the real object is finally made.The design of control software mainly includes the design and implementation of position control and attitude control based on cascade ADRC algorithm.3.Flight test of real aircraft is carried out.On the hardware platform of the quadrotor UAV,the anti-disturbance experiments of hovering control of the quadrotor UAV using active disturbance rejection and cascade active disturbance rejection control are completed to verify the performance of the designed controller.The flight test results show that the hovering control of the quadrotor UAV using the cascade ADRC is more stable,can respond quickly,and has strong resistance to external disturbances.