Modeling and Matching Design of a Tension Controller Using Pendulum Dancer in Roll-to-Roll Systems

Dancer systems are typical equipment for attenuation of tension disturbances. There are two kinds of dancer, active dancer and passive dancer. In the active dancer, a position of dancer roll is measured and the roll is forced by external actuator to regulate tension disturbances. But the passive dancer composed of spring, damper and roll has no external actuator. The tension disturbance generates movements of roll of passive dancer and the displacements regulate the tension variation. But hybrid dancer which is mixture of passive and active dancer is applied for the roll-to-roll systems. It regulates tension disturbances indirectly in the manner of keeping constant position of dancer roll by changing the velocity of driven roller adjacent to dancer roll. It has different characteristics from passive or active dancer. In this paper, a modeling of pendulum dancer is derived and dynamics of hybrid dancer which feedbacks a position of dancer roll and PI control a driven roll is analyzed. Matching logic for gain tuning of hybrid dancer is developed and experimentally verified.