Research On Dynamic Surface Control For Trajectory Tracking Of Quadrotor UAV With Input Constraints

In recent years,with the rapid development of science and technology,the quadrotor quadrotor unmanned aerial vehicle has developed rapidly in hardware and software,and been widely used in military equipment,commercial transportation and private aerial photography.the intelligent requirements for aerial vehicle control systems in various fields have been improving constantly.Therefore,it is of great theoretical significance and practical value to study the trajectory tracking control problem of the aerial vehicle in combination with the actual requirements of the project.In this thesis,considering the existence of control input saturation,unknown external interference,dynamic uncertainty of the model,and immeasurable velocity of the aerial vehicle system,combined with the control method such as backstepping design method,dynamic surface control technology,adaptive fuzzy algorithm and extended state observer,a dynamic surface trajectory tracking control strategy for state feedback and output feedback with input constraints is proposed.Firstly,to solve the the trajectory tracking problem of quadrotor UAV with control input constraints,considering the dynamic uncertainty of the model and the unknown external interference,a fuzzy adaptive dynamic surface trajectory tracking control method is proposed.In this method,the hyperbolic tangent function and the auxiliary system are introduced to deal with the input constraints problems,and the trajectory tracking controllers are designed combining backstepping method and dynamic surface technology to reduce the algorithm complexity,simultaneously,the disturbance observer is designed to estimate the compound disturbance term in the position model,the fuzzy logic system is used to approximate the uncertainties and external disturbances in the attitude model.Secondly,to solve the trajectory tracking control problems with immeasurable velocity and input constraints,considering the dynamic uncertainty of the model and the unknown external interference,an input constraints quadrotor UAV trajectory tracking dynamic surface output feedback control method is proposed.In this method,the trajectory tracking controller is designed combined the backstepping method and dynamic surface technology to avoid differential explosion phenomenon.The constraint function and hyperbolic tangent function are introduced to solve the input saturation problems,and the auxiliary equations are constructed to reduce the saturation effect.The nonlinear extended state observer is designed to obtain the generalized perturbations existing in the position and attitude models while estimating the velocity information of the aerial vehicle system.Thirdly,to solve the prescribed performance trajectory tracking control problems for quadrotor UAV with input constraints,considering the dynamic uncertainty of the model and the unknown external interference,a prescribed performance backstepping dynamic surface control method is proposed.In this method,introduces a prescribed performance function,and converts the original constrained system into an equivalent unconstrained system through error transformation.Furthermore,the trajectory tracking controller is designed combination with the backstepping method and dynamic surface techniques.The hyperbolic tangent function and the auxiliary equation are introduced to solve the input constraints problem,simultaneously,the nonlinear extended state observer is designed to estimate the generalized disturbances of the aerial vehicle system.Finally,simulations of spiral disc rising signal and rectangular signal tracking based on DJI M100 aerial vehicle are carried out.The results show that the control algorithm designed in this paper can effectively overcome the effects of control input saturation,unknown external interference and dynamic uncertainty of the model,the strong robustness and high precision control objectives can be achieved.