Finite-Time Disturbance Observer-Based Finite-Time Robust Attitude Control for Quadrotor UAVs

This article addresses robust attitude control for quadrotor unmanned aerial vehicles (UAVs) under multi-source disturbances. First, the attitude dynamics are reformulated as a linear decoupled system to address the inherent strong coupling in quadrotor UAVs. Second, when the quadrotor UAVs are affected by constant disturbances, a finite-time integral controller (FTIC) is proposed to ensure the convergence of attitude tracking errors. To address time-varying disturbances, lumped disturbances in each channel are precisely estimated via a developed finite-time disturbance observer (FTDO). And then, based on the estimated lumped disturbances, a finite-time composite integral controller (FTCIC) is designed to achieve accurate attitude tracking within finite time. Finally, simulation results demonstrate both robustness and effectiveness in the proposed approach.