Non-linear tension control in a winding process by using the contact roll

Abstract

In a web winding process, the contact roll plays many important roles including air-entrainment control and WIT (Winound In Tension) regulation. The behavior of the contact roll significantly affects the winding tension characteristics specifically at the time of contact and separation when the tangential velocities of contact roll and the winding roll are not synchronized. A new mathematical model which includes the behavior of the web tension, the winding roll, carrage and the contact roll is derived for the control of the winding tension. By using the model derived, a non-linear PID (NPID) controller is designed to control the winding tension at the time of contact and separation between the contact roll and the winding roll. Computer simulation study showed that the performance of the winding system with the NPID controller was significantly improved compared with that of a system with PID controller.