Frequency-dependent distribution of manipulated variables for changing the rolling stock cross section in a roll train

A control device for a roll train to roll rolling stock composed of metal, wherein the roll train has a plurality of rolling stands, through which the rolling stock passes successively in a transfer direction (x) that is uniform for the rolling stands, with the result that the rolling stock is rolled successively in the rolling stands,

• wherein the control device has determination paths, by means of which, based on of a variable (δQ) which is characteristic of the change in a cross section with which the rolling stock is to run out of a particular rolling stand of the roll train, the control device first determines, for the particular rolling stand and a number of upstream rolling stands of the roll train which are arranged upstream of said rolling stand when viewed in the transfer direction (x), a respective provisional manipulated variable (Sb to Se) and, using the respective provisional manipulated variable (Sb to Se), determines a respective final manipulated variable (Sb′ to Se′), wherein the respective final manipulated variable (Sb′ to Se′) influences the cross section with which the rolling stock runs out of the respective rolling stand of the roll train,
• wherein the control device activates the rolling stands in accordance with the respective final manipulated variable (Sb′ to Se′),
• wherein the determination paths of the upstream rolling stands have frequency filters, by means of which the control device determines the respective provisional manipulated variable (Sb to Sd) for the upstream rolling stands by respective frequency filtering of the characteristic variable (δQ) or of an intermediate variable (Zb to Zd) determined from the characteristic variable (δQ),
• wherein the frequency filters are designed in such a way that the determination of the respective provisional manipulated variable (Sb to Sd) for the upstream rolling stands in each case includes only frequency components of the characteristic variable (δQ) which are below a respective limiting frequency (fb to fd),
• wherein in respect of the number of upstream rolling stands of the roll train, the limiting frequency (fb to fd) remains the same or increases from one upstream rolling stand to another upstream rolling stand, and
• wherein the determination path for the particular rolling stand is designed in such a way that the determination of the provisional manipulated variable (Se) for the particular rolling stand includes at least those frequency components of the characteristic variable (δQ) which are above the limiting frequency (fd) of the upstream rolling stand which is immediately upstream of the particular rolling stand when viewed in the transfer direction (x).