Tension Estimation and Control in Winding Process of Web Handling Systems

A long flexible material called web is converted into the final product through various processes such as printing, drying, coating, and laminating using a web handling system. To control the longitudinal tension of the web, a tension feedback control system is generally designed based on the detected tension signal using a tension sensor. However, in several cases, the tension control bandwidth is limited owing to the resonance frequency of the tension sensor and the phase delay caused by the filter in the amplifier. In addition, tension sensors are expensive and cannot be installed in all the processes of large-scale web handling systems. This study investigates the possibility of replacing the signals from the tension sensor in the winding part of a web handling system. The tension estimator is designed based on a model that includes a motor control system and web dynamics to estimate the web tension. The effectiveness of the tension estimation and sensorless control performance was verified by conducting experiments using a laboratory web handling system.