Advanced thickness gauge control system for cold rolling mill in an unsteady state^*

Système perfectionné de réglage d'épaisseur pour laminoir à froid en régime transitoire

Abstract

This paper describes a new thickness gauge control system, which is based on the Observer principle of modern control theory and has the following three features :

— a robust control system against the fluctuations in the rolling characteristics ;

— capability of raising the tuning factor of the BISRA Automatic Gauge Control (AGC) ;

— a system configuration easily added to the previous system.

The effectiveness of this control system has been confirmed by numerical simulation, and the good thickness accuracy and the stabilization of rolling in an unsteady state is assured.

As a result of it, with application of the new system in a reverse cold-rolling mill at Kakogawa Works, the off-gauge length has been reduced to less than about 50 % per coil.