Roll-out of model based control with application to paper machines

Abstract

A mechanistic nonlinear model of the wet end of paper machine 6 (PM6) at Norske Skog Saugbrugs, Norway has been developed, and used in an MPC application. The MPC provides reduced variability in many key variables, and better efficiency through faster grade changes, start ups, and improved control during periods of poor measurements. The model and controller can be rolled-out to other paper machines, as found by studying and fitting the model to data from PM4 at Norske Skog Saugbrugs, and PM3 at Norske Skog Skogn, Norway. No changes to the model, except for parameter values, were introduced, and still the validation results were good. The time spent on fitting and validating the PM6 model to PM4 and PM3 are approximately 1% of the time spent on developing the original model. This should be a strong incentive for focusing on mechanistic modeling in industries were there are many similar production lines or units.