Identification of cross-directional behaviour in web production: Techniques and experience

The paper concerns the problem of parameter estimation in web manufacturing processes such as paper making, plastics extrusion and sheet coating processes. The key feature of such processes is that the manufactured web has width and length. In order to control or monitor the process, it is necessary to be able to identify the behaviour of the web width (cross-direction, in short CD) as well as the web length (machine-direction, in short MD). The aim of the paper is: (1) to review the identification techniques, (2) present a new method based upon basis function sets, (3) to illustrate typical results using industrial data. © 1995.