Observer-Based Finite-Time Nonsingular Terminal Sliding Control of Quadrotor Under External and Mismatched Disturbances

Abstract

In this article, we propose an improved nonsingular terminal sliding mode control method, to achieve finite-time trajectory tracking of a quadrotor uncrewedaerial vehicle in the presence of external and mismatched disturbances. This method is combined with finite-time disturbance observers, which are employed to estimate these two types of disturbances, and it also ensures that disturbance estimation errors can converge to zero within a finite time. To counteract the effects of external disturbances, the control law incorporates their estimation. In addition, we modify the sliding mode surface to include the estimation of mismatched disturbances, which helps to mitigate their impact. Then, we demonstrate the stability of the system using a Lyapunov function, showing that the tracking error will converge to zero within a finite time. Finally, simulation results indicate that the proposed control method can effectively suppress both types of disturbances.