Abstract This paper proposes a novel fixed-time output feedback sliding mode tracking control of marine surface vessels (MSVs) under unknown external disturbances, unmeasurable velocities, unmodelled dynamics and actuator faults (AF). A fixed-time extended state observer (FXESO) is proposed to observe unknown lumped disturbances. Considering the FXESO, a novel fixed-time velocity-free fault-tolerant control law is applied to trajectory tracking based on a fixed-time non-singular fast terminal sliding mode manifold (FNFTSMM). The control scheme is able to make an MSV track a reference trajectory exactly, and the tracking errors can be stabilized to the origin in fixed time. Meanwhile, the upper bounded value of the convergence time does not depend on vessels’ initial values. Finally, simulation results and comparisons illustrate the merits of the proposed control scheme.

中文翻译：

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带干扰消除的执行器故障下海面船舶定时输出反馈滑模跟踪控制

摘要 本文提出了一种在未知外部干扰、不可测量的速度、未建模的动力学和执行器故障 (AF) 下的海面舰船 (MSV) 的新型固定时间输出反馈滑模跟踪控制。提出了一种固定时间扩展状态观察器（FXESO）来观察未知的集总扰动。考虑到 FXESO，基于固定时间非奇异快速终端滑模流形 (FNFTSMM)，将一种新颖的固定时间无速度容错控制律应用于轨迹跟踪。该控制方案能够使MSV准确跟踪参考轨迹，跟踪误差可以在固定时间内稳定到原点。同时，收敛时间的上界值不依赖于船舶的初始值。最后，