Design And Implementation Of The Four Rotor Aircraft Control System

The quad-rotor is a VTOL multi-rotor aircraft. It is very fit for the kind of reconnaissance mission and monitoring task of near-Earth, so it can be used in a wide range of military and civilian applications. The quad-rotor is under-actuated, multivariable, strongly coupled, nonlinear, and uncertainties complex features system. The modeling and controlling have become a hot and difficulty in the control field.In the dissertation, the quad-rotor is researched in details and extensively, and the thesis mainly focuses on the major categories, the field of research, key technology and application prospect. The existing quad-rotor in the laboratory can be studied on modeling strategies and control methods. The detailed analysis and research on the rack structure and dynamic characteristics of the laboratory four-rotor aircraft is showed in the dissertation. The physical model and dynamic model of the four-rotor aircraft are established. It also studies on the force in the four-rotor aircraft flight principles and course of the campaign to make the research and analysis. The four-rotor aircraft has many operating status, such as climbing, downing, hovering and rolling movement, pitching movement and yawing movement. The Newton-Euler model is used to describe the four-rotor aircraft in flight in the dissertation. On the basis of the above analysis, modeling of the aircraft can be made. Modeling of the four-rotor aircraft is divided into the physical modeling (motor, rack, etc.), and dynamics modeling. The physical model is calculated by measuring and making the modeling of the actual four-rotor aircraft. Dynamics modeling is to build models under the principles of flight of the aircraft and a variety of state of motion, and Newton-Euler model with reference to the four-rotor aircraft.The PID control is used to analysis the dynamics and control algorithm design in the dissertation. It can be controlled, such as the roll angle, pitch angle control, yaw control, and a high degree of control, as well as the acceleration of the flight control. The attitude control system and acceleration control system can be verified the feasibility of control methods and algorithms.The hardware platform for the four rotor aircraft is established in the dissertation. The hardware platform is consisted of the attitude control panel of inertial navigation systems and the control board running the control algorithm. Inertial navigation system is consisted of gyro sensors L3G4200Dand the accelerometer ADXL345and altimeter, the master chip is the STM32which can read and write attitude information. The control board is used to run the control algorithm and process the attitude information, which is transmitted from the STM32and some peripheral circuits. Through debugging the control algorithm, the aircraft can fly smoothly by repetitive flight test.