Attitude Estimation Of A Quad-rotor Unmanned Aerial Vehicle Based On Complementary Filter

As a kind of Micro UAV(Unmanned Aerial Vehicle),quad-rotor UAV has special superiorities:simple mechanical structure and strong maneuverability which make the quad-rotor easy to achieve VTOL(Vertical Take-off and Landing),hover at static state and execute acrobat movements.Because of these advantages,quad-rotor UAVs have been developed for performing various missions in both military and civilian areas.However,for quad-rotor UAV the most difficult task is attitude estimation of quad-rotor UAV.The accuracy and speed of the attitude estimation will have a direct impact on the realization and the stability of the control algorithm.Therefore,the attitude estimate problem is a prerequisite for the realization of aircraft control.With the development of MEMS(Micro electro mechanical systems)technology and the computer technology,the measurement for the attitude of four rotor aircraft,generally use low cost inertial measurement unit(IMU),which is mainly composed of three sensors,magnetometer gyroscope and accelerometer.This paper considers the problem of obtaining good attitude estimates from measurements obtained from typical low cost inertial measurement units.The outputs of such systems are characterized by high noise levels and time varying additive biases.Aiming at the basic problem of attitude estimation of a quad-rotor,a detailed analysis of the attitude estimation process is done.A method used to realize attitude estimation is designed based on complementary filter algorithm.Use this method designed based on complementary filter algorithm can significantly reduce the requirements of precision and speed for the processor,this method also can fuse sensor data effectively and achieve high precision attitude estimation.The proposed complementary filter algorithms are implemented in Matlab/Simulink for simulation experiments to verify the validity and effectiveness Then,the thesis makes detailed analysis of the simulation results of the algorithms The simulation figures show that the proposed algorithms can realize the goal of attitude estimates and the performances are guaranteed.The complementary filter algorithms provide a vital theoretical foundation for the practical application of the quad-rotor.