Modelling and simulation of run-out table cooling control using feedforward-feedback and element tracking system

Abstract

This article proposes a simple run-out table cooling control algorithm for an existing hot strip mill. The control system was designed to minimize the retrofit cost and to utilize existing equipment. Special consideration includes response times of top and bottom cooling headers, top header opening sequence, prediction of finisher speed, and strip element tracking. A six-dimensional look-up table was generated for feedforward control using an offline mathematical model which was identified and verified by rolling data. The feedforward loop was designed to obtain the target coiling temperature while the feedbackward loop was applied to attenuate cooling disturbance due to real-time changes of rolling parameters and prediction errors of the mathematical model.