Improving the Availability of Tandem Hot Metal Strip Rolling: The Use of Fault-Tolerant Techniques With Virtual Rolling

It is important in the control of the tandem rolling of hot metal strip to achieve a degree of robustness to faults in certain measurements to avoid degradation of the availability of the process. Examples of such faults are those that would preclude valid measurements in strip tension and roll force. These types of faults could degrade the process availability and seriously reduce the quality and yield of the output, along with a major loss of production and possible equipment damage. In this article, we propose a method of control for this process that permits continuity of operation during possible faults in the tension or roll force measurements and without major disruptions in process operation or significant reduction in the quality of the output. The effectiveness of this method is shown by simulations using data from an operating mill.