Trajectory Tracking Control of Quadrotor UAV

In this paper, a trajectory tracking control algorithm based on backstepping and linear active disturbance rejection control (LADRC) is proposed for the under-actuated and strongly coupling characteristics of the quadrotor UAV. The mathematical model of quadrotor UAV is obtained by Newton-Euler formula, and the system is divided into position control loop and attitude control loop. Because of the characteristics that the quadrotor UAVs linear velocity is not easy to obtain and the disturbance exists in the dynamic environment, linear extended state observer is introduced to observe the velocity and disturbance; The position subsystem controller is designed based on backstepping and the dynamic surface control method is used to reconstruct the virtual control volume to solve the problem of the differential explosion in the classical backstepping; For the problem that the three subsystems of the attitude subsystem are coupled with each other,LADRC is used to design. the attitude subsystem controller, the linear extended state observer is used to estimate and compensate the dynamic coupling part and external disturbance in real time and the PD controller is used to design the state error feedback control law. The trajectory tracking control experiment is carried out in the simulation model established in Matlab/Simulink. The simulation results show that the controller designed in this paper can make the quadrotor UAV achieve good attitude and position tracking with strong robustness.