The Computer Control System and Algorithm for Plate Mill

Abstract

Since 1988, We have made computer control reforming of hydraulic screwdown in five plate mills, and have achieved a series of satisfied system performance such as rapid response, the two side of rolls to move synchronistically, anti-interference etc., we also gained high—accuracy plate thickness. The statistics thickness variations within one plate are in range of 0.25 – 0.60 mm before reforming and are less than 0.03 – 0.15 mm after reforming. The errors of hitting aimed thickness less than ± 0.10 mm, The extreme variations of batch less than 0.07 mm. The techniques of reforming are mainly dynamic intelligent control of hydraulic screwdown system, synchronism control of hydraulic screwdown, eccentricity control method by rotary encoder, the curve of modulus of mill measured automatically, the control algorithm of reducing the variation within one plate, the hitting aimed thickness of plates and the application of stochastic process in AGC system etc. The techniques was fully and successfully industrialized to The Plate Mill of MaAnshan Iron & Steel Co. LTD and Steel Sheet Plant of Shanghai No.1 Iron & Steel Works.