Adaptive nonsingular terminal sliding mode control of cable-driven manipulators with time delay estimation

Abstract

ABSTRACTFor accurate position tracking control of cable – driven manipulators under heavy lumped uncertainties, a novel adaptive nonsingular terminal sliding mode (ANTSM) control scheme using time delay estimation (TDE) is proposed and investigated in this paper. Thanks to the TDE technique, which uses the time-delayed states of the system to properly estimate and compensate the lumped complex system dynamics, the proposed controller is model-free and suitable for practical applications. Moreover, high precision and fast convergence and good robustness against lumped disturbance can be effectively obtained using the NTSM manifold and combined adaptive reaching law. Stability of the closed-loop control system is analysed using Lyapunov theory. Comparative numerical simulations and experimental studies were performed. Corresponding results effectively demonstrate the superiorities of the newly proposed controller over the existing TDE-based NTSM and CNTSM controllers under several classical cases.