Trajectory Tracking Controller Design For Micro-quadrotor Aerial Vehicle

As a kind of Micro UAV (Unmanned Aerial Vehicle), quadrotor UAV has special superiorities:simple mechanical structure and strong maneuverability which make the quadrotor easy to achieve VTOL (Vertical Take-off and Landing), hover at static state and execute acrobat movements. Owing to these advantages, quadrotor UAVs have been used in both military and civilian areas.However, the high performance control of quadrotor UAV is a difficult task because it is a nonlinear, multivariable, state-coupling, under-actuated and uncertain system. The purpose of the thesis is to design appropriate algorithms to realize the trajectory tracking. This thesis focuses on the situation of an external system can be described by a linear differential equations of neutral stability to design a trajectory tracking controller. In this thesis, internal model approach based on the theory of output regulation is used to produce desired feedforward controller and backstepping approach based on the theory of Lyapunov stability is usd to design stabilizing controller. In the presence of external disturbance and uncertain model, the controller adopted in the thesis can make the system track uncertain trajectory.Firstly, the thesis use backstepping approach combined with Lyapunov redesign approach to design flight controllers to make quadrotor track trajectory quickly and accurately according to the under-actuated characteristics and uncertainties. Then, when the track and disturbance is unknown, for the external system described by linear differential equations of neutral stability, the thesis use external system construct the internal model equation, which corrected by the feedback signals and use backstepping method to get stable controller. This strategy leads to strong robustness to amplitude, phase perturbation of external system. Finally, for the external system described by linear differential equations of neutral stability with unknown frequency, the thesis use the backstepping method combined with adaptive internal model control method to solve the limitations of the known external system frequency information and obtain trajectory tracking controller, which are robust to amplitude, phase and frequency perturbations of external systems.Algorithms used in this thesis are implemented in Matlab/Simulink for simulation experiments to verify the validity and effectiveness. Then, the thesis makes detailed analysis and comparisons of the simulation results of the three control algorithms. The simulation figures show that all the proposed algorithms can realize the goal of control respectively and the control performances are guaranteed. The control algorithms provide a vital theoretical foundation for the practical application of the quadrotor.