Machine direction registration dynamics model of a rotary printing press

Abstract

We derive an analytical model of the machine direction registration dynamics of a continuous-web, electronic line shaft (ELS) rotary printing press. We use the model to quantify the affect of tension disturbances on machine direction registration dynamics with different control schemes. With standard ELS registration control schemes, we show the benefits of using a compensator roller vs. electronic differential gear (advance or retard print cylinder's angular position). Next, we develop a novel cascaded reference control scheme for an electronic differential gear controlled ELS printing press that allows it to rival the performance of a compensator roller controlled ELS printing press. Finally, we demonstrate the benefits of using a cascaded reference empirically on a 6-station rotogravure ELS printing press.