This paper presents a novel control approach for a quadrotor unnamed aerial vehicle (QUAV) in the presence of external disturbances. The QUAV system is difficult to control due to the coupling between its attitude and position, and its dynamics subjected to external disturbances. Therefore, an improved fractional-order fast integral terminal sliding mode control (IFOFITSMC) technique is proposed for the attitude/position of the QUAV in this work. The IFOFITSMC improves the robustness of the QUAV system against time-varying disturbances. The adopted fractional-order fast integral sliding mode surface ensures the finite time convergence and the dynamics of attitude and position follow the desired dynamics more quickly. Moreover, the disturbances that affect the QUAV position and attitude are tackled based on adaptive laws without requiring information about the upper bounds of its disturbances. Furthermore, the Lyapunov method is used to prove the stability and the superior tracking error performances of the QUAV in the presence of disturbances. Finally, numerical simulation is presented to show the efficacy of the IFOFITSMC proposed in this work. Also, some previous methods in the literature are used to compare the tracking performances of the proposed technique.

本文提出了一种在存在外部干扰的情况下对四旋翼未命名飞行器（QUAV）的新颖控制方法。由于QUAV系统的姿态和位置之间的耦合以及受到外部干扰的动力学，因此很难控制。因此，在这项工作中，提出了一种改进的分数阶快速积分终端滑模控制（IFOFITSMC）技术。IFOFITSMC提高了QUAV系统抵抗时变干扰的鲁棒性。采用分数阶快速积分滑模表面可确保有限的时间收敛，并且姿态和位置的动力学会更快地遵循所需的动力学。而且，根据自适应定律解决了影响QUAV位置和姿态的干扰，而无需提供有关其干扰上限的信息。此外，使用Lyapunov方法来证明在存在干扰的情况下QUAV的稳定性和出色的跟踪误差性能。最后，通过数值模拟表明了本文提出的IFOFITSMC的有效性。而且，文献中的一些先前方法用于比较所提出技术的跟踪性能。