In this study, trajectory tracking of robotic manipulators under varying loads with uncertainties and external disturbances is obtained by proposing model-independent adaptive fractional high-order terminal sliding mode control (AFO-HoTSMC). The proposed AFO-HoTSMC method is composed of an adaptive high-order terminal sliding mode control integrated with fractional-order (FO) control. An adaptive tuning control is utilised to evaluate the uncertain unknown dynamics of the system without relying on the prior knowledge of the upper bounds. FO control and HoTSMC are used to achieve the fast finite-time convergence, chatter-free control inputs, better tracking performance and robustness. The finite-time 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 with H_∞-Adaptive control, intelligent PD (iPD), intelligent PID (iPID) and adaptive third-order SMC (ATOSMC) are realized to demonstrate the performance of AFO-HoTSMC.

中文翻译：

---

交变载荷下非线性机器人机械臂的自适应分数阶高阶终端滑模控制

在这项研究中，通过提出与模型无关的自适应分数高阶终端滑模控制（AFO-HoTSMC），获得了在具有不确定性和外部干扰的变化负载下机器人机械手的轨迹跟踪。所提出的 AFO-HoTSMC 方法由与分数阶 (FO) 控制集成的自适应高阶终端滑模控制组成。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。FO控制和HoTSMC用于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。研究了整个系统的有限时间稳定性，并从李雅普诺夫稳定性准则中导出。最后，H _{∞ -实现了}自适应控制、智能PD (iPD)、智能PID (iPID) 和自适应三阶SMC (ATOSMC) 来演示AFO-HoTSMC 的性能。