PARTIAL LEAST SQUARES BASED PAPER CURL AND TWIST MODELING, PREDICTION AND CONTROL

摘要

A method is described for using the partial least squares (PLS) technique for modeling, predicting and controlling curl and twist in a paper machine. The prediction variables to the model are selected quality control system measurements and paper machine variables. The selection is based on incremental error analysis of individual prediction variables and can be improved using score contribution analysis. The predicted variables to the model are the curl and twist measurements which are determined from the samples taken at the end of the reel. The PLS model is identified and used in an on-line framework and the model is continuously updated with new data as required. A control strategy to use the PLS model for controlling curl and twist is included. There is also described a method which uses as inputs to the model only the measurements from a fiber orientation sensor and the curl and twist measurements.