An Adaptively Direct Decoupling Register Control Structure for the Accelerating Phase of Roll-to-Roll Manufacturing

The accelerating phase of R2R printing systems is an uncertain, complex and coupling process, which makes the register control challenging. In this paper, an online learning algorithm is presented for a register error model to automatically approximate the accelerating dynamics in the closed-loop control process. Then, an adaptively direct decoupling control (ADDC) method is proposed to eliminate the impacts of the complex coupling and acceleration on the register errors by an adjustable decoupling compensation. The effectiveness of the ADDC method is demonstrated via experiments, while the experimental results indicate that ADDC can rapidly reduce the register errors of the accelerating process and always keep them within
$\pm 5 \times 10^{-5}$
m. Moreover, comparisons of ADDC, well-tuned PD and model-based feed-forward PD control methods are also carried out, and the results show that ADDC owns the highest register precision and least waste material in the three control methods.
Note to Practitioners
—In this paper, an adaptively direct decoupling control (ADDC) method is proposed for the register control of the accelerating phase of Roll-to-Roll (R2R) printing systems. In the ADDC method, an online learning algorithm is utilized in a general register error model to automatically approximate the accelerating dynamics in the closed-loop control process, thereby the decoupling compensation in the ADDC method can automatically adjust to directly eliminate the impacts of the complex coupling and acceleration on the register errors. Experiments are carried out on an industrial R2R printing machine to show the effectiveness of the ADDC method, and the results show that ADDC can rapidly reduce the register errors of the accelerating process and always keep them within
$\pm 5 \times 10^{-5}$
m. Moreover, comparisons of ADDC, well-tuned PD and model-based feed-forward PD control methods are also carried out, and the results show that ADDC owns the highest register precision and least waste material in the three control methods.