Adaptive fractional‐order non‐singular fast terminal sliding mode control for robot manipulators

Abstract

In this study, an adaptive fractional‐order terminal sliding mode controller is proposed for controlling robot manipulators with uncertainties and external disturbances. An adaptive tuning method is utilised to deal with uncertainties which upper bounds are unknown in practical cases. Fast convergence is achieved using non‐singular fast terminal sliding mode control. Also, fractional‐order controller is used to improve tracking performance of controller. After proposing a new stable fractional‐order non‐singular and non‐linear switching manifold, a sliding mode control law is designed. The stability of the closed‐loop system is proved by Lyapunov stability theorem. Simulation results demonstrate the effectiveness and high‐precision tracking performance of this controller in comparison with integer‐order terminal sliding mode controllers.