METHOD FOR CONTROLLING THICKNESS OF STRIP IN CONTINUOUS COLD ROLLING

摘要

PURPOSE: A method for controlling thickness of strip in continuous cold rolling is provided to obtain strip thickness having higher accuracy by obtaining modulus of plasticity, one of important control factors in a strip thickness control system, in such a way that physical rolling effect is reflected in the low speed normal rolling section. CONSTITUTION: In controlling a rolling mill using an AGC (automatic gauge control) system to which an ordinary setup model is applied in cold rolling process, the method for controlling thickness of strip in continuous cold rolling comprises the steps of obtaining an initial roll force during low speed normal rolling P0 by substituting actual data and operation data during low speed normal rolling for a roll force prediction equation; obtaining an initial roll gap value S0 of a hydraulic cylinder on the setup model by substituting the obtained initial roll force P0 for an elasticity deformation equation of the rolling mill; obtaining modulus of plasticity M using the obtained initial roll force P0 by perturbation; and obtaining a roll gap control amount using the obtained modulus of plasticity M, wherein the operation of the rolling mill is controlled in the section where low speed normal rolling is carried out by the initial roll gap value (S0) obtained in the low speed normal rolling conditions and a roll gap control amount (ΔS).