An Adaptive Fault-tolerant Control Method for Robot Manipulators

This paper presents a new method for adaptive continuous nonsingular fast terminal sliding mode control (ACNFTSMC) based on a novel structure-improved extended state observer (SIESO) for fault-tolerant control (FTC). In response to the initial peaking phenomenon in traditional ESO (TESO), which can severely degrade the accuracy and stability of the control system, The SIESO is designed to replace TESO to estimate the lump disturbances/faults. Besides, to address the problem of the unknown estimation error of ESO, an adaptive technique is applied to compensate for the observation error in real-time. To guarantee fast convergence and chattering-free, the CNFTSMC method is employed. Afterward, the stability and rapid convergence of the control system is demonstrated using Lyapunov theory. Finally, the simulation results verify the superiority of the proposed control strategy compared to the other existing advanced control techniques.