Presetting method

Abstract

A preset value of at least one setting value in a shape control actuator included in a cold rolling mill is calculated by a presetting method. In the presetting method, an MC actual value for cold rolling performed in the past is calculated. In the presetting method, an MC target value in a rolled stock to be manufactured by the cold rolling to be performed next is calculated based on the MC actual value. In the presetting method, the setting value is selected so that a difference between an MC prediction value in the cold rolling to be performed next and the MC target value is minimized, and the selected setting value is set as the preset value.

What is claimed is: 
     
         1 . A presetting method of performing cold rolling using a work roll and calculating a preset value of at least one setting value of a shape control actuator included in a cold rolling mill for manufacturing a rolled stock, the presetting method comprising:
 inputting, to a model, input data including an actual value of a rolling load, the setting value, and a prediction value or an actual value of a width distribution of a thermal expansion amount at the work roll in the cold rolling performed in a past to calculate an MC actual value that is a vector in which ratios of mechanical plate crowns to a width center plate thickness at one or more width positions in the rolled stock are arranged;   calculating, based on the MC actual value, an MC target value MC_g that is a vector in which target values of ratios of the mechanical plate crowns to the width center plate thickness at the one or more width positions P in the rolled stock to be manufactured by the cold rolling to be performed next are arranged; and   selecting the setting value in the cold rolling to be performed next so that a norm of a difference Δ represented by Expression (1) is minimized, and setting the selected setting value as the preset value,   
       
         
           
             
               
                 
                   
                     
                       Δ 
                       = 
                       
                         MC_g 
                         - 
                         MC_n 
                       
                     
                     , 
                   
                 
                 
                   
                     Expression 
                     ⁢ 
                         
                     
                       ( 
                       1 
                       ) 
                     
                   
                 
               
             
           
         
         where, MC_n in Expression (1) is a vector in which prediction values of ratios of the mechanical plate crowns to the width center plate thickness at the one or more width positions P are arranged, the vector being obtained by inputting, to the model, prediction input data including a prediction value of the rolling load in the cold rolling to be performed next, the setting value in the cold rolling to be performed next, and a prediction value or an actual value of a width distribution of a thermal expansion amount at the work roll immediately before the cold rolling to be performed next. 
       
     
     
         2 . The presetting method according to  claim 1 , comprising:
 inputting, to the model, the input data including an actual value of a rolling load at a predetermined longitudinal position, the setting value, and a prediction value or an actual value of a width distribution of a thermal expansion amount at the work roll in the cold rolling performed immediately before to calculate the MC actual value; and   setting the MC actual value as the MC target value.   
     
     
         3 . The presetting method according to  claim 1 , comprising:
 storing, in a storage unit, the MC actual value calculated at a timing when a shape of a tip end of the rolled stock is stable and a material type of the rolled stock or a rolling condition in association with each other for each of a plurality of times of the cold rolling performed in the past to create a table; and   extracting, from the table, the MC actual value associated with a material type or a rolling condition closest to the material type of the rolled stock or the rolling condition in the cold rolling to be performed next among the material types of the rolled stock or the rolling conditions included in the table, and setting the extracted MC actual value as the MC target value.   
     
     
         4 . The presetting method according to  claim 1 , comprising:
 storing, in a storage unit, the MC actual value calculated at a timing when a shape of a tip end of the rolled stock is stable and a material type of the rolled stock or a rolling condition in association with each other for each of a plurality of times of the cold rolling performed in the past to create a table;   extracting, from the table, the MC actual value associated with a material type or a rolling condition closest to the material type of the rolled stock or the rolling condition in the cold rolling to be performed next among the material types of the rolled stock or the rolling conditions included in the table, and setting the extracted MC actual value as a first MC target value;   extracting, from the table, the MC actual value associated with a material type or a rolling condition closest to the material type of the rolled stock or the rolling condition in the cold rolling performed immediately before among the material types of the rolled stock or the rolling conditions included in the table, and setting the extracted MC actual value as a second MC target value;   inputting, to the model, the input data including an actual value of a rolling load at a predetermined longitudinal position, the setting value, and a prediction value or an actual value of a width distribution of a thermal expansion amount at the work roll in the cold rolling performed immediately before to calculate a third MC target value that is a vector in which ratios of the mechanical plate crowns to the width center plate thickness at the one or more width positions P are arranged; and   calculating the MC target value based on the first MC target value, the second MC target value, and the third MC target value.