Finite time convergence based on third-order integral terminal sliding mode for tracking control perturbed quadrotor UAV

Abstract

Precise trajectory tracking of quadrotor unmanned aerial vehicles (UAVs) remains challenging due to inherent nonlinear dynamics, external disturbances, and model uncertainties encountered during flight operations. This paper presents a novel third-order integral terminal sliding mode control (3-ITSMC) algorithm for regulating the altitude (z) and roll (ϕ) dynamics of a quadrotor UAV subject to wind disturbances and parametric uncertainties. The proposed controller integrates an integral terminal sliding surface with a third-order super-twisting algorithm, achieving precise tracking with near-zero steady-state error, chattering-free control signal, and rapid finite-time convergence. Rigorously established through Lyapunov stability analysis on Closed-loop stability and finite-time convergence. Extensive simulation results conducted under step and sinusoidal reference trajectories with added sinusoidal wind disturbances demonstrate the effectiveness of the proposed method. The 3-ITSMC reduction in root-mean-square (RMS) up to 98.1% in tracking error and energy savings from 51.2% to 95.3% as compared to second-order (SMC), while maintaining preserving robust disturbance rejection throughout operation. These findings achieve that the proposed 3-ITSMC offers a robust and energy-efficient solution for high precision quadrotor control under realistic flight perturbations.