Control of a quadrotor vehicle using sliding mode disturbance observer

This thesis presents the design of a robust and accurate flight controller for a small four-rotor vehicle. The model of the quadrotor incorporates the dynamics of the vehicle as well as external disturbances (wind, collision, actuator failure) and model uncertainties. The proposed control strategy uses the recently developed Sliding Mode Control Driven by Sliding Mode Disturbance Observer (SMC/SMDO) approach. This technique ensures high robustness to disturbances and uncertainties along with a continuous control computed with minimal increase in computer processing. The complete design of the multiple-loop, multiple-time-scale SMC/SMDO is presented before the robustness and accuracy of the control are validated by extensive simulations run on various trajectories in the presence of external disturbances and model uncertainties.