METHOD OF ESTIMATING UNKNOWN OR IMPRECISELY KNOWN VARIABLES IN A PAPER MAKING PROCESS

摘要

Method of estimating unknown or imprecisely known variables in a paper makin g process wherein a mathematical model of a process is formed, the model including at least one target variable which is unknown or imprecisely known . A plurality of process variables and at least one property of a manufactured paper are measured. At least one of said measured variables or properties is chosen as a reference variable. An initial value is chosen for the target variable for solving the mathematical model and a difference between the simulated reference variable and the measured reference variable is determined. The difference constitutes a cost function which is optimized to estimate the unknown or imprecisely known value of the target variable.