Research On Design Technology Of Automatic Take-off And Landing For UAV

During takeoff and landing process, the height and velocity of an aircraft was very low, and the control ability was reduced. Thus the flight control law in those two phase must have enough precision and robustness, in order to ensure the UAV can carry out a safety takeoff, and land safely and exactly on the runway finally. This thesis concentrated on the design technologies of the auto takeoff and landing, based on the design project of an UAV's flight control system.Firstly, a non-linear model of the UAV was built. Than the aerodynamic characters and maneuvers was studied, to understand the aircraft better. And the conclusion of those analyses was the foundation for the design process of flight control law.Secondly, the screw of the UAV was very large, to avoid it touch the runway, a small alpha takeoff strategy was selected. Than the automatic take-off control law was developed, using integral of the pitch angle, which can restrain the effect of negative pitch moment caused by ground effect and other disturbance, make the vehicle climbing at appropriate velocity and attitude. The robustness of automatic take-off control law was than examined.Thirdly, selected appropriate control strategy according to requirements of the different stages of landing period and features of the vehicle. Than the glide path of descending and flare phases, height control and lateral track control laws were designed. The robustness of automatic landing control law was examined.Finally, the designed automatic take-off and landing control law was validated using a hardware-in-loop simulation environment. The result of the simulation revealed that the automatic take-off and landing control law designed in this thesis were correct and effective.