Coordinating wet end and dry end controls on a fine paper machine

This paper reviews results of a new multivariable optimal controller that i ntegrates scanning sensors with wet end measurements. Results from two mach ines producing SC grades and a fine paper machine making uncoated grades ar e presented. Multivariable control improved variability levels during stead y grade runs but the most remarkable benefit was its ability to handle the upsets such as coated broke changes.