A tensioning pulley set for a straightening machine for straightening a strip or for a re-rolling stand for re-rolling a strip, comprising a first tensioning pulley with a first pulley axis and at least one second tensioning pulley with a second pulley axis, the first tension pulley being a flatness measuring pulley having a force sensor for measuring a radial force applied to the circumferential surface of the flatness measuring pulley, and a drive for the second tensioning pulley with which a torque can be applied thereto on the second pulley axis, either the first tensioning pulley configured without a drive, or an auxiliary drive provided for the first tensioning pulley with which a torque can be applied to the first tensioning pulley on the first pulley axis, the auxiliary drive for the first tensioning pulley being significantly weaker than the drive for the second tensioning pulley.

A method controls the section sizes of a rolled product in a segment of a rolling line between at least two rolling stands, wherein each is provided with its own drive members, in which at least a detector located between the two rolling stands detects a characteristic size of the rolled product. A control unit compares the characteristic size of the rolled product with a reference size and acts on said drive members in order to hold the rolled product in an optimal drawing condition. The method includes setting a predefined value of an electric quantity of at least one of the drive members, measuring the reference size, and verifying the characteristic size of the rolled product in transit. If a deviation is detected between the characteristic size and the reference size, returning the characteristic size of the rolled product to the reference size.

A metal strip is gripped by an upstream set of infeed tension rollers and, downstream therefrom in a strip-travel direction, by a downstream set of outfeed tension rollers. These tension rollers are rotated so as to tension the strip between the upstream and downstream sets and move the strip downstream in the strip-travel direction. Between the sets the strip first passes around individually supported relatively rotatable stretch rollers to increase a plastic stretch ratio of the strip, and then through a plurality of straightening rollers to reduce curvature and residual tension of the strip and also to increase the plastic stretch ratio of the strip.

A rolling control device (10) updates a preset load value P.sub.set based on operation actual results at timings t.sub.a to t.sub.b. The rolling control device (10) derives a plasticity coefficient Q.sub.chk based on operation actual results at timings t.sub.b to t.sub.c. When the determining that it is necessary to re-update the updated preset load value P.sub.set based on the plasticity coefficient Q.sub.chk, the rolling control device (10) updates the preset load value P.sub.set again based on the operation actual results at the timings t.sub.b to t.sub.c.

A rolling control device (10) updates a preset load value P.sub.set based on operation actual results at timings t.sub.a to t.sub.b. The rolling control device (10) derives a plasticity coefficient Q.sub.chk based on operation actual results at timings t.sub.b to t.sub.c. When the determining that it is necessary to re-update the updated preset load value P.sub.set based on the plasticity coefficient Q.sub.chk, the rolling control device (10) updates the preset load value P.sub.set again based on the operation actual results at the timings t.sub.b to t.sub.c.

A method of controlling hot finish rolling, in cooperative control of the hot finish rolling, by controlling a rolling state using an evaluation function in which weight gains are set for each of a plurality of state variables and a plurality of manipulated variables and obtaining control gains that minimize the evaluation function, includes: a step of normalizing the weight gains by a normalization unit; a step of performing, by a comparative evaluation unit, comparative evaluation on the weight gains of the state variables after normalization and performing comparative evaluation on the weight gains of the manipulated variables after normalization; and a step of adjusting, by a gain adjustment unit based on a result of the comparative evaluation, at least one of: the weight gains of the state variables; and the weight gains of the manipulated variables.