Systematic method for determining the controller gains in a multi-span web line

Abstract

A web line may have multiple locations where feedback systems are used to control web and roller speeds, and web tension. The Euclid Web Line (EWL) in the Web Handling Research Center at Oklahoma State University is such a line. The EWL has four sections - unwind, S-wrap, process, and rewind section. The S-wrap establishes the web speed. There are five speed controllers and two tension controllers. For the studies reported in this paper, all controllers are assumed to be Proportional (P) + Integral (I) controllers. A systematic method for finding the controller gains is the primary objective of this paper. The method involves first simplifying the model for each section using a Routh Approximation, and then determining the controller gains based on selected performance criteria. Experimental studies on the Euclid line with the determined gains are presented.