Modern Hot-Strip Mill Thickness Control

The design and implementation of a hot-strip steel mill thickness control system is discussed. The use of structured design techniques and well-tuned control loops produced a thickness control system of world-class performance. A high-level software design approach provided the ability to make quick and accurate modifications to both control loops and tuning constants. Diligent work in the areas of mill calibration, tuning, and simulation resulted in a very effective commissioning stage. Integration of the automatic gauge control with the predictive and adaptive mill setup models resulted in a fully coordinated thickness control system. Control loop strategies and theoretical concepts of hot steel strip rolling are discussed. Performance results achieved during the startup of the Dofasco Incorporated No. 2 Hot Strip Mill are inclulded.