Research On Flight Control Technology Of Quad-rotor Aircraft

Quadrotor aircraft has become one of the hot topics in research fields due to its simple structure,unique flying way and broad application prospects in military and civil aspects.However,its properties of strong coupling,nonlinearity and sensitivity to external interference make it more difficult to design the system controller.Accordingly,in this thesis,the dynamic model of the quadrotor aircraft is set up,and the flight controller with strong adaptive ability and good robustness is designed to ensure flight quality and achieve reliable flight.Firstly,based on the detailed description of the flight principle of the quadrotor aircraft,the fundamental dynamics of the rotor is analyzed by using the momentum theorem and blade element theory.Combined with the force analysis of the aircraft,the nonlinear mathematical model is developed by adopting euler angle to describe attitude movement,and its characteristics are analyzed.Secondly,the overall framework of the control system and the functions of the inner and outer loop controllers are analyzed.Then,aiming at the uncertainties and external disturbance,the attitude controller based on robust servomechanism linear quadratic regulator control and robust model reference adaptive control is designed.The tracking performance and stability of the controller are theoretically proved.Furthermore,the organic integration of the two control methods enhances the robustness of the system and realizes the efficient and accurate control of flight attitude.Thirdly,in order to meet the requirements of hovering and path tracking,the design of the speed and position controllers is based on classical control theory.According to various flight missions,the corresponding guidance instructions and control strategies are formulated to realize the functions of command flight and autonomous flight.Finally,the numerical simulation environment is built under Matlab and the flight simulation of the quadrotor aircraft is completed.The simulation results verify the robustness of the flight control law and the rationality of the guidance instructions.Also,the results indicate that the controller can track the instructions effectively and stably under the external disturbances and parameter perturbations,and satisfies the control requirements.