Fractional-order adaptive non-singular fast terminal sliding mode control with time delay estimation for robotic manipulators

Abstract

In this study, an adaptive fractional-order non-singular fast terminal sliding mode (FO-NFTSM) scheme based on time delay estimation (TDE) is proposed for the control of robotic manipulators. A new FO-NFTSM surface with a continuous TSM-type switch item is designed to ensure good performance, such as fast finite-time convergence, high precision and being nonsingular. The chattering problem is solved by introducing a saturation function into the control signal. The TDE element is used to estimate the robot's unknown dynamic parameters and external disturbances. The Lyapunov stability theory is used to prove the finite-time stability of the control system. The proposed control algorithm is applied to a two-link robotic manipulator and the comparative results verify the effectiveness and superiority of the proposed control approach in comparison with existing control methods.