A finite-time fault-tolerant control strategy for quadrotor using a novel reaching law

Abstract

This paper presents a finite-time fault-tolerant control strategy based on a novel reaching law, which is proposed as a solution to the trajectory tracking problem of a quadrotor unmanned aerial vehicle (UAV) in the presence of external disturbances, system uncertainties, and actuator faults. First, a novel adaptive reaching law is proposed, which enables the sliding mode surface to approach the origin with minimal rate, thus effectively reducing the chattering. Then, a high-order sliding mode observer (HOSMO) is designed to estimate the unmeasured linear velocity and the lumped uncertainties. Furthermore, the controller is designed by combining a non-singular fast terminal sliding mode (NFTSM) and the novel reaching law. It is demonstrated that the controller is capable of achieving convergence of the tracking error to zero within a finite time frame. The simulation outcomes substantiate the efficacy of the proposed control methodology, particularly in mitigating chattering.