Quaternion-Based Hybrid Feedback for Global Trajectory Tracking Control of a Quadrotor UAV with Smooth Control Input

This paper addresses the global trajectory tracking control problem of a quadrotor UAV using unit quaternions. First, the thrust and quaternion-based desired attitude are derived from the virtual position tracking controller. Then, a quaternion-based hybrid attitude controller is employed to ensure global asymptotic stability (GAS) of the overall closed-loop system while preventing the well-known "unwinding phenomenon". Furthermore, to address the discontinuities in control input torque induced by discrete jumps, a smooth hybrid feedback control scheme is proposed, ensuring continuous control torque for global tracking. Finally, simulation results are presented to validate the performance of the proposed hybrid controllers.