Resonant Frequencies in Web Lines and Filtering of Web Tension

Abstract

A state space system model is proposed to predict the resonant frequencies of an idler system consisting of idler rollers and web spans between two driven rollers. A close match between the experimental results and the model simulations validate the correctness of the dynamic model. The relationship between system parameters and the system's minimum resonant frequency is investigated through analytical and numerical analyses. An analytical approximation of the minimum resonant frequency is developed for a special class of idler systems consisting of equal span lengths and any number of idle rollers. A Kalman filter is designed based on the web span tension dynamic model in terms of state errors. Extensive comparative experiments with and without the Kalman filter show improvement in the web tension signal when the Kalman filter is used.