Robust trajectory tracking control for quadrotor UAVs with time input saturation constraints

Considering the trajectory tracking challenges faced by quadrotor UAVs during flight due to input saturation, external disturbances, uncertainties in system parameters, unmodeled dynamics, etc., a finite-time input saturation robust trajectory tracking control method is proposed. To address external disturbances, a nonlinear disturbance observer is employed for real-time estimation. System parameter uncertainties are approximated using neural networks. Input saturation in the system is handled by an auxiliary system. Finite-time controllers based on backstepping design are implemented in both position and attitude control loops to control the system. By utilizing Lyapunov stability theory, it is proven that all error signals in the closed-loop system are bounded and converge. Simulation results confirm that the proposed control algorithm ensures precise trajectory tracking by quadrotor UAVs in finite time, demonstrating strong robust performance.