摘要 |
The present invention relates to an algorithm used in a method and apparatus for controlling a paper machine, in order to automatically tune parameters used to calculate the initial value of web moisture percentage at a dryer part inlet after grade change and parameters used to calculate the dry-bulb temperature of air within a hood. In the method and apparatus, a regression line correlating the ratio of a difference in bone dry basis weight before and after grade change with a difference between the predicted value and steady-state value of steam pressure is determined from a plurality of point-of-grade-change data items, and a first parameter is calculated from the slope of this regression line. With the method and apparatus of the present invention, it is possible to automatically determine the value of the first parameter using earlier point-of-grade-change data, which used to be determined empirically. It is also possible to obtain parameter values in which the intrinsic properties of the paper machine in question are factored, by determining a regression line and calculating the values of parameters best suited to earlier data.
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