Research And Design Of The Flight Control System For Quad-rotor UAV

Quad-rotor unmanned aerial vehicle has the characteristics of simple structure, vertical take-off and landing, stable, flexible and so on. Because of the advantages, Quad-rotor is attracting much attention in scientific research fields, civil markets and military fields these years, with important application values. However, its stable flight must be realized by flight control system. Since the Quad-rotor is a typically nonlinear, strong coupling multi input and multi output system, the design and implementation of its flight control system means the research and design of its mathematical model, motion information observer, motion controller and so on.The project focuses on the research and design of the flight control system of Quad-rotor, which could be divided into five parts: hardware system design, mathematical modeling, sensor measurement system design, attitude controllers design and position controllers design. Firstly, the electronic hardware is designed, the performance parameters of the main sensors are obtained and the main flow of the program is established. Secondly, the mathematical model for its kinematic and dynamic analysis is built by Newton-Euler Method. Also, the main parameters of the model are measured by experiment and the mechanical model of the motor-rotor is learned. Thirdly, according to the interference sensor performance and the interference of sensors’ measurement caused by the flight environment, the window sliding digital filter and Butterwotrh digital low pass filter are designed to filter the noise. Also the data fusion algorithms with complementary filter for attitude heading reference system and integrated navigation system are designed to get more accurate angular motion information and linear motion information.Fourth, according to the angular motion model, the PID controller with doubleclosedloop are designed, as well as the nonlinear state error feedback controller based on the time-optimal feedback synthesis function, which is the emphasis. And through simulation, comparative analysis and actual flight, the effectiveness of both controllers are proved with the latter has the advantages of rapidity and stability Fifth according to the linear motion model, the feedforward and feedback PI controller for controlling the acceleration of vertical direction is designed, as well as the three closed loop state error feedback controller and LQR controller for altitude control and double-closed-loop PID controller for horizontal motion control. And the effectiveness of each controller is proved by simulation, analysis and actual flight. Finally, the research and design of the Quad-rotor flight control system are completed, and the six degree of freedom motion of the Quad-rotor is realized.