Model based precise register control method for shaft-driven Roll-to-Roll(R2R) systems

Abstract

Shaft-driven Roll-to-Roll (R2R) printing systems have advantages in keeping the printing rolls synchronously rotating, thereby reducing the register errors of R2R printing systems. However, tension oscillations and propagation are still inevitable due to other factors such as disturbances, which lead to the fluctuation of register errors. In this paper, a new mechanical model is established for the shaft-driven R2R systems. Then, a model-based precise control (MBPC) method is proposed, in which an implicit coupling algorithm is designed for the cooperate actions of the dancer rolls to rapidly suppress the tension oscillations and propagation. The stability of the proposed control system is proved via Lyapunov analysis. Moreover, the effectiveness of the proposed modeling and control method is verified via an industrial example. The results indicate that the proposed model can accurately characterize the dynamics of the R2R systems, and the MBPC can effectively eliminate the register errors caused by the tension oscillations and propagation, through the implicit coupling algorithm. Additionally, the results also demonstrate that the MBPC can increase the register precision of package manufacturing R2R systems into ±40 micrometers, which is superior to the existing control method.