In this paper, fractional calculus theory is employed to inspect a finite time fault tolerant controller for robotic manipulators in the presence of uncertainties, unknown external load disturbances, and actuator faults, using fractional-order adaptive backstepping approach in order to achieve, fast response and high-precision tracking performance. Knowing the advantages of adaptive controllers an adaptive form of the above controller is then established to deal with the overall uncertainties in the system. The most important property of the proposed controller is that we do not need to have knowledge about the actuator fault, external disturbances and system uncertainties exist in system. In this study two important achievements are made. The first one is that the finite time convergence of closed-loop system is ensured irrespective of initial states values. The second one is that the effects of the actuator faults and other uncertainties are attenuated by the suggested controller. The performance of the suggested controller is then tested for a PUMA560 robot in which the first three joints are used. The simulation results validate the usefulness of the suggested finite-time fractional-order adaptive backstepping fault-tolerant (FOAB-FTC) controller in terms of accuracy of tracking, and convergent speed.

中文翻译：

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机器人机械手的有限时间分数阶自适应反步容错控制

在本文中，分数阶微积分理论用于在存在不确定性、未知外部负载扰动和执行器故障的情况下检查机器人机械手的有限时间容错控制器，使用分数阶自适应反步方法以实现快速响应和高精度跟踪性能。了解自适应控制器的优点后，就可以建立上述控制器的自适应形式来处理系统中的整体不确定性。所提出的控制器最重要的特性是我们不需要了解系统中存在的执行器故障、外部干扰和系统不确定性。本研究取得了两项重要成果。第一个是保证闭环系统的有限时间收敛与初始状态值无关。第二个是执行器故障和其他不确定性的影响被建议的控制器减弱。然后针对使用前三个关节的 PUMA560 机器人测试建议控制器的性能。仿真结果验证了建议的有限时间分数阶自适应反步容错 (FOAB-FTC) 控制器在跟踪精度和收敛速度方面的有效性。