Study Of Flight Control Algorithm For Quad-rotor Aircraft

With the continuous development and maturity of the space technology, quadrotors are widely used in military and civilian fields by its characteristic of low cost, high performance, unique structure and the way of flight, etc.. By reviewing the state of the art, research focus and control methods of the four rotor aircraft, this thesis takes flight control algorithm as research topic, mainly focusing on quadrotor dynamics modeling, designing three flight control algorithm, and proving the correctness and effectiveness of the proposed algorithm by the digital simulation experiment.The main contents and research results of this paper include:1. Nonlinear mathematical model established:Based on the mechanical structure and control principle of the quadrotor, nonlinear system model is derived in detail from two angles of dynamics and kinematics by selecting the key forces and moments of system, and simplified under the assumption.2. The control of quadrotor based on the PID control algorithm:controllers of the inner and outer ring of system are designed with PID algorithm. Simulation results show that the quadrotor system is able to precisely reach the target position and maintain a stable hover.3. The control of quadrotor based on backstepping:for underactuated system, quadrotor flight control system is designed by backstepping in light of Lyapunov stability criteria. Furthermore, control effective is verified through simulation experimental. The results show that backstepping control is better in the performance of the stable time and reaching the desired position than classic PID control.4. The control of quadrotor based on adaptive backstepping method:as close to the actual flight environment and solve the system uncertainty in the process of flight, the adaptive backstepping is presented and simulation in the jamming condition. The results show that the system has good stability and robustness.In this thesis, a nonlinear mathematical model of the system was established, and three kinds of flight control algorithm were presented, which provide an robust theoretical basis for the future study of the quadrotor.