Modeling and robust decentralized control for speed-up phase of web processing systems for composite elastic web

Abstract The web processing system for composite elastic web contains two unwinders and a compounding processing, which is used for transporting two various webs to form a kind of composite web with desirable properties. The physical properties of the web materials before and after compounding will undergo essential changes, and the motion characteristics of compounding roll shaft and the web tension are more complicated than the common systems, which makes it challenging to establish the physical model. In this study, a physical model is firstly established based on the general physical laws. Then, the variation dynamic model of web processing systems is built under the speed-up situation by Taylor expansion. Next, the method of interval matrix is introduced to deal with the problem of wide-range variation of radius and inertia of the unwinding/rewinding roller, parameter uncertainties and production speed changes. Subsequently, the web processing system is taken as an interval system, based on which a robust decentralized controller is proposed. Sufficient conditions of the existence of the proposed controller are obtained based on Lyapunov theory. Finally, the simulations are performed on a five-motor driven system and the results illustrate that the proposed method is effective and can improve the control performance.