Two-layer saturated PID controller for the trajectory tracking of a quadrotor UAV

This research presents a complete control scheme for the trajectory tracking of a quadrotor UAV, based on a twolayer saturated PID approach. The Newton-Euler formulation is used to model the complete dynamics of the aircraft, extracting two sets of interconnected equations; this is, the orientation and position dynamics. Two main control layers are designed where the inner fast loop deals with the orientation dynamics, getting reference from the outer loop, controlling the translational dynamics. The orientation control layer is designed with saturated torques, as well as saturated motor-speed outputs, while the position controller saturates the control forces. Simulation results of a quadrotor aircraft, performing the tracking of an elliptical spiral trajectory, are presented as a validation tool for the proposed scheme.