A 2-Link Robot with Adaptive Sliding Mode Controlled by Barrier Function

Abstract

This paper focuses on designing several controllers to attenuate the chattering problem: a conventional sliding mode controller (CSMC) with a barrier function (BF) and a saturation function (SF), and an adaptive sliding mode controller (ASMC) with SF as well as ASMC with BF.The key distinction between CSMC and ASMC lies in the fact that ASMC doesn't require knowledge of the upper bounds of uncertainties and the determination of gain.ASMC can minimize the magnitude of control signals to an acceptably low level.Despite perturbations such as parameter uncertainty (PU), external disruption (ED), and the friction coefficient of Coulomb (CF), both CSMC and ASMC can effectively handle the 2-link robot.They stabilize the robot manipulator and achieve the required joint position.Due to the ASMC's lower controller gain compared to CSMC, the amplitude of the chatter (zigzag motion) has been minimized.Simulation results using MATLAB 2018a/Simulink demonstrate that the ASMC outperforms the CSMC in achieving more favorable outcomes.