Design Of Quadrotor Aircraft Control System

Compared to the ordinary aircraft, quadrotor aircraft has the advantages of simpler structure, lower failure rate, each unit of volume can produce greater lift and so on. Therefore, quadrotor aircraft has a broad prospect of application that attractes many researchers and becomes the new hot topics at home and abroad.Quadrotor aircraft flight controller is the most central part of the aircraft, enabling aircrafts to autonomous flight without manipulation from outside. Therefore, the development of high performance flight controller is of great importance. Meanwhile, the design and research of flight controllers has a considerable foresight in technology.Firstly, this article describes the quadrotor aircraft’s background and current status of research, then introduces the quadrotor aircraft’s flying principle. After that, comes out with the mathematical model of quadrotor aircraft and makes analysis of the quadrotor aircraft theoretically.Secondly, this article introduces the hardware design of the quadrotor aircraft’s flight system. Chose microcontroller STM32F103CB as the flight controller’s main controller and chose sensors as following:accelerometer ADXL345, gyroscopes L3G4200, electronic compass HMC5883, barometer BMP085and ultrasonic wave sensor HC-SR04.Thirdly, this article introduces the software design of the quadrotor aircraft’s flight system in detail. Including the introduction and classification of the inertial navigation system, coordinate system, the definition of attitude angles and the calculation method of attitude. At last, designs a attitude detection system based on quaternion and kalman filter. After that, introduces the PID control algorithm and designs a attitude control system based on improved variable parameter PID control algorithm.Finally, this article does a test of the quadrotor aircraft’s hardware, attitude detection and attitude controlling. The result of the test proves that the flight controller has a stable control over the quadrotor aircraft’s attitude, completes the specified task and achieves the expected goals. Then points out the weakness and shortcomings of the current flight control system and the mission for further work.