High-order Fully Actuated System Approach for a 3-DOF Quadrotor Control Based on Extended State Observers

This paper focuses on position tracking control of a 3-DOF quadrotor under practical disturbances. High-order terms of system states, inputs, and disturbances are generated after the highly coupled underactuated quadrotor system is converted into two high-order fully actuated (HOFA) systems. To observe high-order terms for control design, which were not previously discussed in other approaches, as well as disturbances rejection in control, we developed extended state observers (ESOs) of the HOFA systems for the 3-DOF quadrotor. The convergence of ESOs is rigorously proven using the Lyapunov stability theory. Furthermore, we present the simulation results to verify the proposed observer and control design for the HOFA models of the 3-DOF quadrotor.