Application of least-squares fitting in roll gap control in a 20-high mill
GAO Zhaobo
Chen Xu
MA Buqiang
HU Yujia
ZHEN Yongfu
Abstract：The non-deterministic functional relationship between the oil cylinder position and the roll gap position in the 20-high rolling mill makes it difficult to determine the roll gap value required in the roll gap control,resulting in the low yield of high precision thin strips.For this problem,based on the analysis of the roll system structure of the 20-high rolling mill,the multiples of oil cylinder displacement and roll gap value are synthesized,and the polynomial basis function is selected based on the least square principle to fit the nonlinear discrete sequence of oil cylinder displacement and roll gap position in the rolling process,so as to realize the explicit expression of the position of the oil cylinder and the position of the roll gap,and complete the engineering calculation of the position of the roll gap in real time according to the displacement of the cylinder.The method is easy to program to meet the requirements of automatic control,and has been applied to the roll gap control of 20-high mills in many sites.The improvement of the calculation accuracy of the roll gap value effectively improves the thickness control performance of the rolling mill and ensures the yield of high precision thin strips.
Keywords：20-high rolling millroll gap controlAGCnonlinear fitting
Publication Date：2024-11-20
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：6( 18-23 )