The Research And Implementation Of Control System For Quadrotor Aircraft

Quadrotor Aircraft,also known as quadcopter,is a multi-rotor aircraft which has compact structure,high mobility,low failure rate,and VTOL(Vertical Take-Off and Landing).Compared with the traditional aircraft,it has the advantages of simple physical structure,wide application range and low cost.For the past few years,with rapidly increasing applications in more fields,such as commercial photography,agricultural plant protection,disaster early-warning and military reconnaissance,the quadrotor has been exposed to the public’s view with each passing day.Naturally,it has become the hotspot of many researchers.In addition,the quadrotor also make a figure in real-time exploration of construction progress,real-time mapping,community security monitoring,urban traffic patrols and cluster wireless communications,which creats many new demands for services.Therefore,the study of the quadrotor has remarkable and far-reaching significance.In comprehension,this thesis mainly studies the working principle,dynamic modeling and analysis,design on hardware and software platform with final realization and debugging of the control system.In this design,the structure and operating principle of the quadrotor are briefly introduced.The Cortex-M4 series STM32 micro-processor is used as the control core.The six-axis motion sensor MPU-6050 and digital compass HMC5883 L are composed of IMU(Inertial Measurement Unit)of the flight control system based on FreeRTOS.Firstly,the control system analyzes the collected wireless PPM remote control signal,and then estimate the attitude data measured by the accelerometer,gyroscope and magnetometer.Secondly,it calculates the required PWM control signal adjustment amount for controlling the brushless motor.Finally,it realize the control of the motion attitude of the quadrotor.The flight control system uses the quaternion to represent the attitude,and adopts the techniques of balance fusion filtering to obtain the attitude of the aircraft.The double closed-loopcascade PIDcontrol systemconsists of angle control and angular velocity control,optimizes the mobility.Ultimately,this design accomplish the required stability of the quadrotor.