Compensation method for tension disturbance due to an unknown roll shape in a web transport system

The condition of rolls has significant influence on the process conditions such as longitudinal tension and lateral error in web transport systems such as in metal and film processes. In particular, a roll-shape defect such as an eccentricity is a major cause for the periodic tension disturbance in the web. In this paper, the authors aim to reject these disturbances caused by unknown shapes of rolls. In order to reject the tension disturbance due to the roll shape, an adaptive eccentricity estimator and eccentricity compensation methods are proposed. The validity of the compensation method including the adaptive eccentricity estimator was tested through computer simulation and experimental study.