Self-Tuning Nonlinear Control System Design for Roll-to-Roll Printing Systems

This article proposes intelligent nonlinear web tension and velocity controllers for roll-to-roll printing systems. The introduction of the perturbed machine model makes it easy to handle machine nonlinearities and parameter variations, simultaneously, with the simple static and first-order dynamic compensator. The feedback gains of web tension and velocity are automatically updated by the proposed self-tuner, which corresponds with the first feature of this article. As the second feature, the introduction of disturbance observers in place of the regulation error integrators provides an improved disturbance rejection performance and offset-free property, which is rigorously analyzed based on the Lyapunov stability criterion. The closed-loop performance improvement is numerically demonstrated under various scenarios using MATLAB/Simulink.