Observer-based critically damped feedback systems for nonlinear roll-to-roll printing machine applications under decentralized strategy

This article exhibits an advanced observer-based single-loop feedback system for roll-to-roll (R2R) machine tension control applications by treating the nonlinearities, parameter uncertainties, and closed-loop performance inconsistency as the main challenges. The proposed solution provides the three features as follows: (a) a critically damped web velocity feedback system governed by double integral control with active damping terms and a disturbance observer (DOB) through first-order pole–zero cancellation (PZC); (b) a model-free second-order PZC observer enabling feedback for the tension derivative information; (c) a combination of a proportional–integral (PI) controller, nonlinearly structured PI gains, active damping terms, and a DOB to assign critical damping performance to each tension loop through first-order PZC. The simulation results numerically validate the feasibility of the proposed solution.