Robust UDE-Based Saturated Control for Quadrotors in Waypoint Tracking Flights

This paper investigates the waypoint tracking problem of a quadrotor in the presence of external interference and actuator saturation. Specifically, the saturation issue induced by the waypoint switching in classic feedback control is systematically addressed. The dynamic model of quadrotor is first provided and then simplified into six second-order subsystems. Based on this model, a UDE-based saturated control is proposed to achieve position tracking while avoiding actuator saturation in waypoint flights, thus improving the transient performance of the system. The stability of the proposed control system is proved using the algebraic theory for linear time-varying systems. Comparative simulation results show performance advantage of the proposed control over the classic cascade PID controller and bounded UDE-based controller.