Modified Fast Terminal Super-Twisting Control for Uncertain Robot Manipulators

摘要

The objective of this work is to improve tracking control of uncertain robotic manipulator systems. Parameter variations, unmodeled dynamics and unknown perturbations affect the tracking performance of robots which add more challenges to a model-based nonlinear controller. The proposed approach in this paper utilises a modified terminal super-twisting that has a dynamic model of the sliding function and a new stability conditions which ensures good tracking, prevents chattering and resolves the singularity in nonlinear terminal switching functions. The developed modified fast terminal super-twisting controller ensures accurate joint position tracking while bypassing the singularity problem and removing the chattering phenomenon. Finally, it is shown through analytical analysis and numerical simulations that the proposed nonlinear control technique is robust, presents less chattering than the standard super-twisting algorithm in addition to faster convergence of the tracking error to zero.