An Optimized Feedforward Decoupling PD Register Control Method of Roll-to-Roll Web Printing Systems

Roll-to-roll (R2R) printing provides a continuous printing process to print the multicolor patterns onto the flexible strip materials. The process of aligning successive print patterns on the material to form a multicolor pattern is called print registration and the registration error is the position misalignment between the two adjacent overlapped patterns. In previous studies, many works focused mainly on the dynamic model analysis and the accuracy of print registration, but few of them took the volatility of control signal into consideration, which may cause the great impact to drive motors. In this work, an optimized feedforward decoupling PD register control method is derived to generate optimized control signal without the loss of accuracy of print registration, where a novel membrane algorithm inspired by the biological functioning of cells communicating by means of delivering biochemical objects is developed to search the optimal compensation control signal instead of the exact compensation control signal. Results obtained from the simulations and industrial practice on a 7-axis rotogravure printing press show that our method can significantly decrease the 1-norm and 2-norm of control signal without losing the accuracy of print registration. The proposed method may provide a feasible way to smooth the control signal and decrease the impact to drive motors in R2R web systems.