There exists two theories about the splitting mechanism of cellulose fiber:chain-splitting theory and chain-sliding theory at present.

This paper is concerned with semi-active control of vertical vibration for continuous beam by variable dampers and puts forward the semi-active control law based on the sliding mode theory.

On the theory of sliding mode controlling, this paper presents the method of dual PID regulation based on overshoot, by which both the small overshoot and the short settling time are realized.