Adaptive rejection of quasi-periodic tension disturbances in the unwinding of a non-circular roll

In this paper, an adaptive algorithm is designed to compensate roll noncircularity perturbations in web transport systems. The noncircularity of a roll creates tension disturbances whose frequencies are slowly varying due to the change of radius of the roll. The magnitude and phase of these disturbances are estimated through an adaptive algorithm that cancels their effect. Simulations and experimental results demonstrate the validity of the perturbation model. The ability of the algorithm to reject noncircularity perturbations with slowly varying frequencies is shown through simulations as well as experimental results.