Operating method for a multi-stand rolling mill train with strip thickness determination on the basis of the continuity equation

An operating method for a multi-stand rolling mill train, wherein a strip is fed to a rolling stand in question of the rolling mill train with a known input thickness and exits the rolling stand in question with a strip thickness, the method comprising:

• detecting measurement variables characteristic of the inlet-side velocity of the strip and the outlet-side velocity of the strip with respect to the rolling stand in question,
• determining the inlet-side velocity of the strip and the outlet-side velocity of the strip with respect to the rolling stand in question on the basis of the detected measurement variables,
• determining the strip thickness with respect to the rolling stand in question on the basis of the input thickness, the inlet-side velocity of the strip and the outlet-side velocity of the strip,
• taking further measures in the light of the determined strip thickness,
• wherein at least one of the measurement variable for the inlet-side velocity of the strip is the roller circumferential velocity of the rolling stand arranged immediately prior to the rolling stand in question and the measurement variable for the outlet-side velocity of the strip is the roller circumferential velocity of the rolling stand in question,
• modeling the peripheral precession of the strip in the respective rolling stand, and
• determining the respective velocity of the strip on the basis of the respective roller circumferential velocity and the peripheral precession of the strip in the respective rolling stand.