A new method for suppressing high-frequency chattering in sliding mode control system

A method for suppressing high-frequency chattering in a sliding mode control system is presented. A conception of sliding region is introduced and the switching surface is replaced by two acceptable switching surfaces. Then the control is designed according to the reaching law when the system state is outside the sliding region, and a set of equivalent controls are adopted when the system state is driven into the sliding region. By the proposed method the continuity of the control input is guaranteed, so, chattering is efficiently reduced, the invariance of sliding motion is maintained. Control performances are investigated when there are switching delay, external disturbances and modeling errors