Two-Level Nonlinear Tracking Control of a Quadrotor Unmanned Aerial Vehicle

This study presents a nonlinear tracking control design for a quadrotor unmanned aerial vehicle (UAV) with a two-layer control architecture. In order to facilitate the control design, a decoupled dynamic model is derived for the quadrotor UAV. Backstepping method is employed to stabilize the closed-loop system and to achieve output tracking. The control structure has a high-level layer for producing the guiding state trajectories, and a low-level layer for tracking in both altitude and attitude dynamics. The designed control scheme can well handle the model nonlinearities as well as the drag effects, and can be directly implemented to produce the PWM control signals. Simulation results are provided to verify the efficiency of the proposed control scheme.