Research On Stability Flight Of Small Quadrotor UAV

At present,the four-rotor UAV is notonly and widely used.In the military field,the trend of its application agriculture,construction,exploration,minerals,real estate and many other fields are also booming.UAVs are gradually entering people's lives.With the diversification of its functions,various industries have also put forward higher performance requirements.Therefore,it is the top priority to improve the performance in the future research of UAVs.The control system and attitude calculation of the four-rotor UAV is the core condition for ensuring the stable flight of the UAV,which works it a great necessity to study the control algorithm of it.Firstly,this paper introduces the mechanical structure and the flight principle of the four-rotor UAV,defines the inertial coordinate system and the body coordinate system,analyzes the coordinate transformation matrix,performs aerodynamic analysis and derives the nonlinear system model of the quadrotor.Secondly,a control system based on extended state observer is designed.The robust sliding mode algorithm and adaptive robust sliding mode algorithm are used to control the quadrotor.The stability of extended observer and position and attitude sub-control system in the system are proofed.A wavelet filtering algorithm based on wavelet decomposition reconstruction and a complementary filtering algorithm for attitude fusion are proposed to filter out noise interference and improve the accuracy of the quadrotor.Finally,the experiments of four-rotor UAV control algorithm comparison and the simulation of multi-sensor information fusion algorithm based on wavelet filtering are carried out.The experimental results that are analyzed in detail and show that the four-rotor UAV control algorithm proposed in this paper has good stability and fast response speed.The proposed wavelet-based attitude solving method has significant effect on filtering noise.