Robust Speed Controller Design Method Based on Fuzzy Control for Torsional Vibration Suppression in Two-Mass System

Abstract

This paper presents a robust speed controller design method based on fuzzy logic control(FLC) for robust torsional vibration suppression control scheme in rolling mill drive system. This method proposes a torsional vibration suppression controller that comprises a reduced-order state feedback controller and a PI controller whose motor speed and observed torsional torque are fed back. By using the mechanical parameters estimated by an off-line recursive least square algorithm, a speed controller for torsional vibration suppression and its gains can be determined by FLC with the Kharitonov’s robust control theory. This method can yield a robust stability with a specified stability margin and damping limit. Even if the parameters are varied within some specified range, the proposed control method guarantees a highly efficient vibration suppression. By using a fully digitalized 5.5 kW rolling mill drive system, the effectiveness and usefulness of the proposed scheme are verified and obtained experimental results.