Active vibration rejection in steel rolling mills

This contribution is concerned with vibration rejection by nonlinear control techniques in steel industry, particularly in rolling mill plants. The high quality requirements of rolled products, especially in relation to the thickness tolerances, mean a challenging task also from a control point of view. The key part of this contribution deals with so-called wrapper rolls as well as chatter vibration phenomena. With regard to the control design a mathematical model based on physical considerations is introduced where the essential nonlinearities of the system are taken into account. For the purpose of vibration rejection two nonlinear control concepts based on energy considerations and the theory of differential flatness are presented.