A new mill-setup system for hot strip finishing mill integrating a processmodel and expertise

This paper describes a new mill-setup system for a hot strip finishing mill in the iron and steel making industry, that integrates process models and operator expertise, Operator expertise is expressed in terms of roll gap di fferences between neighboring stands to avoid excessive loads that may lead to unstable rolling. The problem is formulated as that of minimizing devia tion between the know-how-based roil gap difference pattern and the actual one. In order to realize such mill set-up considering the roll gap differen ces in actual plant, in which the computational time is strictly restricted , an estimation method of the Jacobian matrix for solving the problem is pr oposed. The efficiency and validity of the method are discussed, based on t he linear system theory and case study results of simulations. The method i s found to have valid computational properties for applying to the actual s et-up of the process. Applying the system to the actual plant, it was found that operator intervention has been markedly reduced compared with the con ventional set-up method. Furthermore the stability of operation, ie. a decr ease in the frequency of defective roils, is also achieved.