Research On Control Of Small Hybrid Vertical Takeoff And Landing UAV

In order to solve the traditional fixed wing UAV landing site limitation,rotor UAV navigation range small,hybird VTOL UAV appeared.Hybird VTOL UAV is equipped with the rotor VTOL function in the traditional fixed wing,and has the advantages of large range of fixed wing UAV is easy to realize the long endurance.This kind of new configuration of UAV it has very high research value in the field of civil and military fields.How to control the hybird VTOL UAV from VTOL to the level of direct flights is the focus and difficult of the study.During the transition process,the control capability of the hybrid vertical takeoff and landing UAV varies with the change of thrust,the change of balance in the transition process,and the simultaneous action of the rotor system and the fixed wing system,which results in the great change of UAV model,the increase of system input and the coupling between the rotor system and the fixed wing system.Due to the limitation of maximum power,the change of control capability after the change of shape or thrust,and the change of balance in the process of conversion,the transition flight mode of VTOL UAV is more complex.Firstly,the unmanned mechanism and the transition process are briefly introduced.In order to facilitate analysis and modeling,the common coordinate systems are constructed and the transformation matrix between coordinate systems is deduced.Based on the basic theories of flight mechanics and hydrodynamics,a six-degree-of-freedom non-linear mathematical model of hybird UAV rotor model is established,and the obtained mathematical model of rotor model is simplified,aiming at the characteristics of under-actuation,the attitude and altitude tracking controller of rotor mode is designed by backstepping method,and the attitude angle control and hovering simulation experiments are carried out to verify the performance of the designed controller.Firstly,the unmanned mechanism and the transition process are introduced.A six-degree-offreedom non-linear mathematical model is established for the rotor mode of a hybrid vertical takeoff and landing UAV.Aiming at its underactuated characteristics,the attitude and altitude tracking controller of the rotor mode is designed by backstepping method.The attitude angle control and hovering simulation experiments are carried out to verify the performance of the designed controller.Then the rotor in the transition part and the fixed wing part for the integration of modeling,calculation of the hybird VTOL UAV transition process longitudinal nonlinear dynamic equations.By linearization and decoupling of transverse and longitudinal small perturbation of the transition process model is established,and the different equilibrium model for pole analysis.According to the characteristics of the model changes during the transition process,to establish the vertical transition process of LPV model.Application of gain scheduling design method of linear quadratic regulator two tracking controller based on the speed and height,and simulated.The system model of dramatic changes in the traditional gain scheduling method control effect is poor,can not guarantee the global stability of the system,and the controller design requires experience and a large number of experiments.The application of guardian maps theory is designed based on the altitude and velocity tracking controller,and the simulation experiment is carried out.,the results show that the controller has good control effect in the state transition process under.Compared with the traditional gain scheduling method,H_∞ controller design based on guardian maps theory can ensure the global stability of the transition process and the parameters of the controller can be automatically obtained,which reduces the workload of designing the controller.