Robust PI-LPV Tension Control with Elasticity Observer for Roll-to-Roll Systems

Vincent Gassmann, Dominique Knittel (University of Strasbourg, France)

Flexible materials such as textiles, papers, polymers and metals are transported on rollers during their processing. Maintaining web tension in the entire processing line under an expected web speed is a key factor in achieving good nal product quality. 

Estimated Web Elasticity

It is common practice in industrial web transport systems to use decentralized PI-type controllers. The performances of such control strategies highly depend on web speed and elasticity because of the strong coupling between these two variables. Moreover web speed and elasticity are subject to large variations during a same processing. The emphasis of this paper is on the design of linear parameter varying PI controllers with quadratic performance to increase closed-loop system robustness regarding these parameters variations. The minimization of the cost function is performed by the software modeFRONTIER, tailored at solving optimisation problem with genetic algorithms.