Nonlinear web tension control of a roll-to-roll printed electronics system

Roll-to-roll printed electronics (R2RPE) is a low-cost and high-efficiency manufacturing method for high-density circuits printed on flexible substrates. Stable web tension control is essential for excellent printing quality. However, due to many uncertainties in terms of the model errors, roll machining errors, and external disturbances, etc., it is difficult to guarantee the tension control accuracy especially for conventional control methods. For this purpose, a nonlinear model predictive control (MPC) scheme is proposed to eliminate the tension disturbance of the R2RPE system. The dynamic model of the unwind roller is firstly established, and then the factors affecting the web tension are analyzed. The nonlinear dynamic matrix control (NDMC) based on an auto-regressive and moving average (ARMA) model is introduced to eliminate the tension disturbance. To evaluate the effectiveness of the proposed control method, the tension controls using the traditional proportional-integral-derivative (PID), fuzzy PID and proposed NDMC are simulated with MATLAB for performance comparisons. Finally, an R2RPE prototype is fabricated for performance tests. The experimental results validate the effectiveness of the proposed control scheme. Keywords: Roll-to-roll printed electronics, web tension control, dynamic modeling.