Application Of Data Mining In Strip Shape Control Of Cold Rolled Strip

At present,the application of "Big Data" in cold rolled strip shape data mostly focuses on data storage,reading and so on.Most of them are only used to establish a data platform which can be read quickly.How to integrate data mining technology with strip shape data processing is still to be developed.This subject takes 1740 production line of a domestic cold rolling mill as the research object.Data mining is used to process extremely large amount of shape data.Flatness evaluation system is developed.PDA off-line data generated in rolling process are analyzed rapidly.Target information is extracted from the data and realized by analysis,processing and pattern recognition.The trend and statistical results of flatness components of corresponding coils are obtained by shape quality evaluation.The flatness control level of the object is clearly analyzed and the flatness evaluation system is improved.The main findings are as follows:(1)The flatness problems in 1740 production line of a domestic cold rolling mill are analyzed in large quantities,and new flatness control technical objectives are formulated according to the analysis contents and design indexes of the mill.(2)An application program for quality analysis and evaluation of cold rolled strip based on Windows platform has been developed independently.Taking the shape data files collected by IBA PDA as the analysis object,it supports the processing and output of shape information,the three-dimensional display and quadratic component analysis of shape measurement value,the input display and storage of shape target curve,the extraction and output of rolling speed curve,and the means of shape adjustment(roll inclination curve,work roll bending curve).The extraction and output of intermediate roll bending curve and intermediate roll tandem roll curve have realized the extraction and analysis of cold rolled strip shape data,and solved the problem that a large number of strip shape data are only stored in the form of index and neglected.(3)According to the order of common carbon followed by high strength,the flatness data of 1740 production line in a domestic cold rolling mill during rolling process are analyzed in detail,and it is found that there are different degrees of quadratic wave defects in the main steel grades.The high strength steel plate problem is more serious,mainly concentrated in the symmetric wave shape problem.The shape of common carbon steel is relatively good,and the influence of width and thickness on the fourth wave shape is obvious.(4)Based on Pearson's correlation theory,the influencing factors of the fourth wave shape value of product shape are analyzed in detail.According to the analysis results,the causes of the problems and the shape control rules of the intermediate roll series,the intermediate roll bending and the working roll bending on the main steel grades are found out in the factors of reduction distribution,rolling force,bending roll and roll channeling.