Disturbance Observer Based Adaptive Fault-Tolerant Attitude Control of a QUAV Using FNTSM

In this paper, a novel adaptive fault-tolerant controller based on fast non-singular terminal sliding mode (FNTSM) and a disturbance observer are developed for a quadrotor unmanned aerial vehicle (QUAV) with external disturbance and actuator fault. Firstly, a fault-tolerant controller is devised to ensure QUAV's stability in flight even in the event of actuator fault. Subsequently, a finite-time disturbance observer is developed to offset the effects of disturbances, including external bounded disturbances and internal uncertainties in the system. Finally, the efficacy of the proposed control methods is demonstrated through theoretical analysis and numerical simulations.