Web machine coordinated motion control via electronic line-shafting

Most current multi-axis web machine controllers are not designed to possess the inter-axis stiffness properties that were the inherent coordinating force in historical mechanically coupled “line-shafted” multi-axis web machines. As a result, these controllers cannot maintain coordination for all operating conditions. This paper presents the development of an “electronic line-shafting” control technique which serves to replicate and even improve on the historical mechanical line-shafted properties. This technique was implemented on a five-axes filament winding machine to evaluate such control during periods when the drive was in torque limit, velocity limit, or simply responding to asymmetric load-induced disturbances. The results demonstrate that the “electronic line-shafting” technique significantly improves the coordination, robustness, and overall stability of multi-axis web-handling machines subjected to realistic physical limitations