To guarantee a good productivity and a better quality of the industrial systems, it is necessary to know the evolution of its various parameters but also its operation mode. The main goal of this work is to carry out a study to improve a flatness control in a reversing cold rolling mill, precisely the web winding system part. We designate by a winding process any system applying the cycles of unwinding, transport, treatment and winding to various flat products. This system knows several constraints such as the thermal effects caused by the frictions, and the mechanical effects provoked by metal elongation, that generates dysfunctions due to the influence of the process conditions. For this installations type, the various automatisms functions, often very advanced, are realized in modular systems with distributed architecture. Our main goal is to obtain a precise thickness, with the best possible regularity. With this intention, we are preceded to the modelling and the control of the nonlinear dynamic behaviour of a web winding process
