Technology Of Automatic Carrier Landing For Flying-wing Unmanned Aerial Vehichle

Fly-wing unmanned aerial vehicles(UAV)is ideal for use on aircraft carriers since it has large payload,long stay time,small aerodynamic drag,small space requirements,countries with powerful aviation capability has been committed to its key technology and application research.The United States is currently the only country in the world to achieve the fly-wing UAV on the aircraft carrier and its own landing.France,Britain,Germany and other countries have also completed the UAV development and test with a variety of flying-wing layout.China only have a homogeneous UAV with flight test,there is no real sense of the carrier-based UAV.Thus the research of the autonomous landing technology of fly-wing UAV,the early realization of UAV aircraft carrier in the autonomous landing have become a top priority in China’s military technology development,also with significant research significance.The carrier-based aircraft is affected greatly by the carrier movement and complex ship-wakes because of the small airspeed,and the landing point is restricted by the specific range of the deck,leading to a difficulty during landing.Therefore the precise tracking of moving target deck for the guidance law is required,as well as rejecting the disturbance of complex environment during carrier landing for control law is important to ensure accuracy and robustness.New guidance and control law algorithm are proposed to address the key problems of self-guided guidance and control of automous carrier landing,and new guidance and control scheme of carrier landing are simulated in MATLAB.The main research contents can be described as follows:1)A scheme of integrated guidance and control based on nominal trajectory is proposed.In view of the characteristics of the sample UAV and the specifications of the carrier landing,the system architecture includes three levels: nominal trajectory,guidance and control.In the outermost layer of trajectory,the generation of nominal trajectory depends on the stage of the autonomous landing and the flight mode.In the middle guidance layer,the guidance law based on sliding mode control theory is proposed according to the nominal trajectory or dynamic trajectory UAV flight path,so that it has a stronger maneuverability.The innermost control layer using disturbance rejection adaptive reference model control law,improve the capability of disturbance rejection of unmanned aerial vehicles.Within this control system architecture,it is possible to realize the precise landing of the UAV on the aircraft carrier in the complex environment with ship movement and flow disturbance.2)A guidance law based on higher order integral sliding mode control theory is proposed.This kind of guidance law integrates the advantages of integral sliding mode control with high order sliding mode control.By introducing the saturation function to modify the controller,it has the advantages of constraining oscillation and improving robustness,and is suitable for non-minimum phase system control of unmanned aerial vehicles.As long as the perturbed bounded condition is satisfied,the sliding mode guidance law can realize the stable tracking of the maneuvering target under various uncertainties and external disturbances.3)An disturbance rejection flight control algorithm based on multivariable model reference adaptive theory is proposed.For the matching and mismatch interference terms,the disturbance rejection model reference adaptive state controller: including association matrix,ideal matching model,LDU decomposition and adaptive law and so on.The advantages of the control algorithm are that the response is fast and the inhibitory effect versus various types of uncertain disturbance is strong,also can satisfy the steady and transient performance of the system at the same time.Finally,the numerical simulations of the proposed nominal trajectory,guidance law and control law are carried out under simulated sailing conditions in MATLAB.The simulation results show that the proposed guidance-control scheme is reasonable and feasible,the guidance and control law are effective,and meet the design requirements.