Periodic Tension Disturbance Attenuation in Web Process Lines Using Active Dancers

Abstract

This paper investigates the role of active dancers in attenuation of web tension disturbances in a web process line. A general structure of the active dancer is considered; governing equations for web spans upstream and downstream to the dancer roller are developed. A structural limitation that facilitates efficient design of the active dancer system for web tension disturbance attenuation is derived and discussed based on the developed model. An open-architecture experimental web platform is developed for conducting real-time control experiments using the active dancer system. The active dancer system model is experimentally identified using the standard system identification techniques available in literature. Three types of control designs were investigated for the active dancer system: a proportional-integral-derivative controller, an internal model based controller, and a linear quadratic optimal controller. Data collected from a series of experiments using the three control designs validate the usefulness of the active dancers in attenuating web tension disturbances in a web process line. A representative sample of the experimental data is presented and discussed.