Zur Modellierung und aktiven Schwingungsunterdrückung in Stahlwalzanlagen

This contribution is concerned with the system theoretic analysis and the active rejection of a vibration phenomenon in (steel) rolling mills, which is known as chatter. For the purpose of the system analysis and the controller design a mathematical model of a multi-stand rolling mill is presented, which describes particularly the strip deformation process such that a non-circular roll/strip contact arc as well as the coupling of the mill stands is taken into account. With this model it can be shown that a mechanical feedback can cause an instability in dependence on the operating point. This fact explains the so-called third octave chatter. For its active rejection two proposals are made, which take the essential nonlinearities of the system into account. The first one presents a passivity-based controller and the second one a controller which is based on differential flatness.