Design And Simulation Of A Small Unmanned Tilt Rotor Aircraft Flight Control System

The main content of this article are two parts: modeling the nonlinear flight dynamics of the aircraft and control system design. First of all, rotor aerodynamic model of a small unmanned tilt rotor aircraft is established base on blade element Theory and by combining with wind tunnel test data of the aircraft the wings, fuselage, flat tail and vertical tail aerodynamic are modeled, then combine the aerodynamic model of each part into a complete nonlinear flight dynamics model of a small unmanned tilt rotor aircraft. The nacelle angle-speed flight envelope is calculated by trimming and analyzing the nonlinear flight dynamics mode. linearize the nonlinear model based on small perturbation theory and analysis the stability and maneuverability of small unmanned tilt rotor aircraft. Design a conversion trajectory from helicopter flight mode to fixed wing aircraft flight mode. Secondary, design the control law of small unmanned tilt rotor aircraft attitude, according to the linear model, using H∞ loop shaping robust control method.The whole conversion corridor is divided several control areas,then speed loop control law is designed with the PID control method on the basis of the attitude control law. Put forward schedule strategy of different controllers. Complete the nonlinear simulation of attitude control, speed control and conversion process around the whole conversion corridor of small unmanned tilt rotor aircraft.