Flight Control Law And Landing Strategy For Shipboard Tail-Sitter Coaxial Rotor Aircraft

The tail-sitter rotor aircraft studied in this thesis is a new configuration of shipboard aircraft.It has three flight modes that are helicopter mode,transition mode and fixed-wing mode.It is of great importance to study its flight dynamics and flight control issue.In this thesis,the flight dynamics,control law and landing path planning of tail-sitter rotor aircraft were studied in depth.In this thesis,the mechanism modeling method was used to derive the nonlinear dynamics model of the tail-sitter rotor aircraft.Two transition paths were proposed for the transition mode,namely the stall transition and the arc-shaped transition.At the same time,by taking advantage of the control surface redundancy,in order to perform the smooth transition between different flight modes,the control surface fusion technique was studied to assist the trimming of the flight dynamics model.The results of the two transition paths was analyzed.The flight state variables of the tail-sitter rotor aircraft in three flight modes change significantly.In this thesis the nonlinear dynamic inversion was utilized to design the corresponding control law for each mode,because the dynamic inversion control possesses a fairly good performance in terms of decoupling and controlling of the multi-variable systems.To compensate the errors caused by the imprecision of the flight dynamics model,an Artificial Neural Network was incorporated.The designed control law was verified by simulation under all three flight modes.According to the flight characteristics of each mode of the tail-sitter rotor aircraft,the carrierlanding control strategy was determined,and the landing path planning algorithm and landing guidance law were derived.The tracking performance of the controller was verified by numerical simulation.On this basis,the visualized simulation was performed by using the visualized simulation of a joint platform of MATLAB/Simulink and FlightGear flight simulation software to provide visual aid of the landing procedure.The simulation results show that the designed algorithm has high control performance.