A New Robust Control Method for Robotic Manipulators Using A Combination of A Fixed-time High-order Sliding Mode Observer and Finite-time Sliding Mode Control

This article proposes a new robust control strategy using a combination between a fixed-time high-order sliding mode observer (FxTHOSMO) and finite-time terminal sliding mode control (FnTTSMC) for robotic manipulators. First, a FxTHOSMO is proposed to approximate the lumped uncertainties. Then, a FnTSMC algorithm is designed based on a finite-time global Fast terminal sliding mode surface and Fast reaching control law to establish a global finite-time convergence of the system. The hybrid control system provides superior characteristics such as high tracking accuracy, less chattering occurrence, finite-time convergence, and robustness against the lumped uncertainties. The stability and convergence of the control system are validated by using the Lyapunov theory. Computer simulations applied to a 3-DOF robotic manipulator are conducted to verify the effectiveness and outstanding properties of the proposed control algorithm