Research And Application Of Automatic Gap Setting Algorithm In Hot Tandem Rolling Mill

Nowadays, there is still a wide gap between our country and the world leading level in hot strip rolling technology. Meanwhile, the requirement of gauge and flatness quality of strip steel products has been raised higher and higher by customers. A significant way to improve the strip steel products’ dimension quality is to get the accurate rolling parameters setting values for the rolling automation system. Hence, the study of high performance and precise gap calculate algorithm is very important for the improvement of hot strip steel’s quality.Research of this thesis is part of the Automatic Gauge Control system for the650mm hot tandem rolling mill developed by the Automation Institute of Northeastern University. This thesis designed a complete automatic gap setting procedure and algorithm and applied it in real strip steel rolling progress.As follows are the research contents in this thesis:(1) Study of hot strip rolling theory and relevant rolling parameters’models. The theory of mill gap zeroing, mill stiffness measuring, load distribution, rolling temperature calculation and rolling force calculation are detailedly described.(2) This thesis established the main procedure and functioning progress of mill gap zeroing, mill stiffness measuring and a complete automatic gap setting procedure and algorithm for this650mm hot tandem rolling mill, the whole rolling parameters calculation models and progress were clearly explained.(3) Through site commissioning of the project, content of this thesis was successfully used in real strip rolling progress. With the real-time data and curves, the mill stiffness measuring and mill gap zeroing method used in this thesis was analyzed. Also, five different dimensions were used in load distribution and rolling force calculation to evaluate the accuracy of the models used in the gap calculating algorithm by comparing the actual value and the calculated value, factors that influenced the calcution accuracy were also analyzed.Results proved that the algorithm in this thesis had a rather high accuracy and stability, hence improved the quality of the gap setting values in the hot tandem finishing mill.