Sliding mode control reduced chattering for with dependent uncertainties

Previously, a paper is suggested to reduce the chattering of sliding mode control by on-line adjusting the width of the boundary layer based on the state norm of an uncertain linear system. It is claimed that the new design can effectively eliminate chattering while at the same time ensuring almost perfect control accuracy. In this note, simulations are presented to show that the state-dependent boundary layer design is effective only if the system is subject to state-dependent uncertainties and no external disturbance.