Research On Position And Attitude Control Of Quadrotor

In recent years,the small quadrotor has become a hot area in UAV research.Quadrotorcraft has the advantages of simple structure,strong maneuverability,low cost and easy maintenance,and can take off and land vertically and can hover over the air.Due to the great application value of quadrotor in military and civil fields,many domestic and foreign universities and research institutes have put themselves into the research of flight control of quadrotorcraft.Quadrotorcraft widen its field of research in the fields of aerodynamics,computer control technology,automatic control theory and modern control technology.Among them,airborne sensors and processors are the most important components of flight controllers,and are the key devices for the autonomous flight of quadrotor.In this paper,we take the quadrotor as the research object which is based on the self-designed flight control circuit board and aircraft mechanical structure.The main works around the four-rotor aircraft in this paper are attitude control,position control and its function development.First of all,we introduced the research status quo of quadrotorcraft at home and abroad,and summarized the main control methods at the present stage.And then,we introduced the flight principle and aerodynamics of quadrotorcraft.Based on the principle of motion,we established a six DOF mathematical model for quadrotorcraft.In addition,the Euler angle method,quaternion method and direction cosine method are introduced.In this paper,we used the quaternion method and the Euler angle method to update and describe the attitude,and used the cascade PID design for the attitude controller and the actual commissioning.Based on this,we have achieved the desired effect.At the same time,we designed the sliding mode attitude controller and verified it by simulation.Secondly,in order to obtain the vertical state of the aircraft accurately,the flying height and climbing speed of the aircraft are obtained by using IMU and barometer.In order to accurately feedback the yaw angle of the aircraft and release the position control coupling of the aircraft in longitude and latitude,the magnetic compass was rectified.Based on the above ideal attitude control,under the participation of barometer,magnetic compass and GPS sensors,the height controller and the horizontal position controller are respectively designed for the position control,and the airborne hovering of the UAV is realized.Finally,based on the fixed-point hovering of the quatrotor,some functional developments are carried out,including the unmanned aerial vehicle based on Lyapunov navigation vector field,the multi-aircraft formation based on LF theory and the automatic tracking and shooting of UAV based on navigation information and image information.The above researches are validated on the actual platform under the premise of the theoretical derivation and the simulation effect.And we achieved in the embedded flight control equipment,and obtained the satisfactory results.