In this study, trajectory tracking of robotic manipulators with uncertainties and external disturbances is obtained by proposing model-free adaptive fractional super-twisting sliding mode control (AOFSTSM). The proposed AOFSTSM method is composed of an adaptive super-twisting sliding mode control integrated with fractional-order (FO) control. An adaptive tuning control is utilized to evaluate the uncertain unknown dynamics of the system without relying on the prior knowledge of the upper bounds. Moreover, FO control and super-twisting sliding mode control are used to achieve the fast finite-time convergence, chatter-free control inputs, better tracking performance and robustness. An output feedback (OF) is proposed and the state estimation is obtained by robust exact differentiator. Furthermore, the stability of the overall system is investigated and derived from the Lyapunov stability criterion. Finally, to validate the effectiveness and robustness of the developed control method, comparative simulations of state-feedback and OF of proposed method with fractional-order nonsingular fast terminal sliding mode control are realized to demonstrate the performance of AOFSTSM.

中文翻译：

---

机器人机械手输出反馈自适应分数阶超扭滑模控制

在这项研究中，通过提出无模型自适应分数超扭曲滑模控制（AOFSTSM）获得具有不确定性和外部干扰的机器人机械手的轨迹跟踪。所提出的 AOFSTSM 方法由与分数阶 (FO) 控制集成的自适应超扭曲滑模控制组成。自适应调谐控制用于评估系统的不确定未知动态，而不依赖于上限的先验知识。此外，使用FO控制和超扭曲滑模控制来实现快速有限时间收敛、无颤动控制输入、更好的跟踪性能和鲁棒性。提出了一种输出反馈（OF），并通过鲁棒的精确微分器获得状态估计。此外，研究了整个系统的稳定性，并从李雅普诺夫稳定性判据导出。最后，为了验证所开发控制方法的有效性和鲁棒性，实现了状态反馈和所提出方法与分数阶非奇异快速终端滑模控制的 OF 的比较仿真，以证明 AOFSTSM 的性能。