Research And Implementation Of The Control Algorithm For Quadrotor Aircraft

The quadrotor aircraft is a type of UAV(Unmanned aerial vehicles).Due to its simple structure,vertical take-off and landing,easy to control and so on,it has attracted a lot of attention for a long time.Especially in recent years,with the overcoming of related technical difficulties and the upgrading of production and manufacturing level,the quadrotor has gradually appeared in people's vision,which has been applied in aerial photography,public safety,agriculture and other fields.No matter from the market potential or the application value,the quadrotor has great development space,and the research institutes and companies all over the world have joined in the research and development of the quadrotor aircraft.This paper focuses on the construction of mathematical model,attitude control and the realization of system functions of the quadrotor aircraft.The main work is as follows:(1)This paper analyzes the dynamics and kinematics principle of the quadrotor,sets the intertial coordinate system and fuselage coordinate system to calibrate the space position of the aircraft.The Euler angles,direction consine matrix and quaternion are used to describe the aircraft's movement attitude and the transformation relationship between them,and the mathematical model of the aircraft is established finally.(2)This paper studys the control algorithm of quadrotor aircraft,from the sensor data acquisition to data filtering,attitude calculation,attitude control and other related algorithms.The second-order low-pass filtering and Kalman filtering are used in data filtering,the quaternion method and direction consine matrix method are used in attitude calculation,and the back-stepping control algorithm is used in the attitude control.In order to improve the traditional back-stepping method for better suppressing interference,this paper introduces a coordinate transformation to accelerate the convergence speed of the system,thus achieving the role of interference suppression.(3)The STM32F103 series chip is used as the control core of the aircraft to control the sensor MPU6050,communication module,motor and other components,and the whole software layer of the aircraft is constructed under the bare metal system.According to different upper computer terminals,this paper uses different wirelessmodules to realize their functions.QT software is used to set up a PC-side and mobile-side upper computer to achieve the aircraft attitude control,status display and video transmission and so on.Finally,the UCOSIII operating system is transplanted on the STM32F103 chip,the software layer of the aircraft is constructed on the basis of this operating system,It is found that it is more convenient to build the aircraft program under the operating system than in the bare metal system.This paper tests the algorithm and related modules in the actual flight of the aircraft,which proves the effectiveness of the proposed algorithm and modules.