Modeling And Control Of A Micro Quadrotor

Nowadays the development of Unmanned Aerial Vehicles (UAV) is the topic with growing interest in both research and industry area. The quedrotor, propelled by four rotors, is one of the typical UAVs. It has a Vertical Take-Off and Landing (VTOL) structure and the maneuverability comparing to fixed-wing aircraft. Due to these characteristics, quadrotors can be widely used in different areas, such as surveillance, search and rescue, indoor navigation and mapping. And the control algorithm is the main concern in quadrotor design because of the poor performance of quadrotors in stability.The purpose of the research in this thesis is to develop two efficient control techniques, including Proportional-Integral-Derivative (PID) control and Linear Quadratic (LQ) control, to achieve the attitude control and altitude control of a self-designed quadrotor.In order to apply the control algorithms, firstly, a mathematical model of quadrotor dynamic system was derived by using the Newton-Euler Mechanics. Then a full simulation model of a micro quadrotor UAV based on the dynamic system was presented in MATLAB and Simulink environment. Since the quadrotor is an unstable system, the PID control algorithm and LQ control method were applied in the simulator respectively to control the attitude and altitude of the vehicle and to achieve the stabilization in flight. In addition, a prototype based on the Arduino microcontroller with an accelerometer and a gyroscope was created to obtain basic parameters for the simulator and test the performance of the control algorithms.Various simulations were performed on the quadrotor nonlinear dynamic model with a PID controller and the quadrotor nonlinear dynamic model with a LQ controller in MATLAB and Simulink respectively in order to compare and evaluate the performances of both controllers.Finally, the simulation results prove that both control techniques are effective in obtaining the desired attitude, desired altitude and the stability of the quadrotor in flight. The LQ controller is better than the PID controller at response time and overshoot.However, the PID controller will be further implemented in the real on-board control of the quadrotor due to its overall good performances.