Nonlinear Control For Trajectory Tracking Of A Quadrotor Unmanned Aerial Vehicle

The application of quadrotor Unmanned Aerial Vehicle(UAV)in civilian and military fields is gradually increasing characterized by its lightweight,flexible,convenient and low cost,and is getting more and more attention from people.The trajectory tracking control is the basis of the quadrotor UAV flight,and is also one of the key technologies of quadrotor UAV control.In order to improve the trajectory tracking control accuracy of quadrotor UAV and achieve more accurate flight track control,this thesis designed a kind of nonlinear trajectory tracking controller based on integral backstepping and verification of the actual flight experiment has been done.In order to improve the anti-interference ability of trajectory tracking controller,a nonlinear trajectory tracking controller based on adaptive integral backstepping is designed and verified by simulation experiment.Firstly,the mathematical model of quadrotor UAV's actuator and six degrees of freedom dynamics model is studied.Based on the established mathematical model,the trajectory tracking control system of the quadrotor UAV is designed.In this control system the actuator is regarded as a rapid response single loop and the force and torque are regarded as the control inputs of mathematical model.According to the model of the actuator,the real actual motor control signal can be calculated,and then is assigned to each motor,and compared with the traditional quadrotor UAV control system which is more close to the engineering practice.Secondly,the trajectory tracking control of quadrotor UAV can be divided into the attitude control and position control,the corresponding controller is designed based on the integral backstepping respectively,and the step response simulation experiment of the attitude control and position control are carried out which verify the designed controller can improve the response performance compared with the traditional PID controller.Considering the actual flight of motor under the condition of high frequency vibration interference and sensor noise,the quadrotor UAV trajectory tracking control simulation experiment is designed and the simulation results verify the effectiveness of the designed trajectory tracking controller.Thirdly,in view of the quadrotor UAV system existing in the model uncertainty and external disturbance,the adaptive law is added to the integral backstepping controller,which has carried on the trajectory tracking simulation experiment and the experimental results verify that the designed controller has better estimation results for interference.Finally,based on QBall2 flight control experiment platform,a trajectory tracking flight experiment based on the integral backstepping is carried on.And compared with the experimental results of traditional PID trajectory tracking control,the actual flight experiment results show that the controller designed in this thesis has better tracking performance than the traditional PID,for the engineering application of nonlinear trajectory tracking controller which provides an effective control method.