Methods and apparatus for locally changing a roll gap in the region of the strip edges (10) of a rolled strip (1) in a rolling stand (2). The roll gap can be changed locally in the region of the strip edges (10) of the strip (1) during the hot rolling. Axial displacement of the working rollers (3, 4) in opposite directions is by a displacement distance s, where s is greater than or less than Δr/tan(α) and Δr indicates the wear of the running surface (8) in the radial direction (R) and α indicates the pitch angle of the conical portion (7) of the respective working roller (3, 4).

A method ascertains control variables for active profile and flatness control elements for at least one rolling stand for hot rolling metal strip with a plurality of i=1 . . . I successive passes and for ascertaining profile and center flatness values for the hot-rolled metal strip. The occurrence of fluctuations in the center flatness of the metal strip after the individual passes and the resulting disadvantages for the rolling stability and the product quality are prevented. The method provides that, also for the target center flatness of the metal strip after a predetermined pass k with i=1 . . . <k< . . . I and for the target center flatness after the subsequent passes, pass-specific interval ranges are also specified in each case, and in that the successive calculation of the control variables and profile values is then carried out taking into account such additional specifications as well.

A profile straightening apparatus 5 for a profiling system which is used to produce a metal profile 4 by roll profiling along a longitudinal axis of the metal profile. The profile straightening apparatus is intended for correcting axial deviations of the metal profile from a prescribed profile geometry, and includes a frame 8 and having at least two interacting correction rollers 6, 7, which are mounted in the frame, receive the metal profile between them and, in relation to the longitudinal axis of the metal profile, are adjustable in two radial directions and also in at least one direction of rotation. The profile straightening apparatus is equipped with force measuring sensors for any forces F.sub.y, F.sub.z acting in the metal profile in one or both radial directions and for any torques M.sub.x acting in the metal profile in a direction of rotation about the longitudinal axis.

A profile straightening apparatus 5 for a profiling system which is used to produce a metal profile 4 by roll profiling along a longitudinal axis of the metal profile. The profile straightening apparatus is intended for correcting axial deviations of the metal profile from a prescribed profile geometry, and includes a frame 8 and having at least two interacting correction rollers 6, 7, which are mounted in the frame, receive the metal profile between them and, in relation to the longitudinal axis of the metal profile, are adjustable in two radial directions and also in at least one direction of rotation. The profile straightening apparatus is equipped with force measuring sensors for any forces F.sub.y, F.sub.z acting in the metal profile in one or both radial directions and for any torques M.sub.x acting in the metal profile in a direction of rotation about the longitudinal axis.

A metal strip is rolled in a roll stand and a control device for the roll stand determines, by means of a working cycle, a number of manipulated variables for flatness actuators of the roll stand and actuates them accordingly. The control device implements an optimizer, which provisionally sets the current correction values, and determines a totality of flatness values. Then, the optimizer minimizes the relationship by varying the current correction variables. When determining the current correction variables (s), the optimizer considers linear ancillary conditions, based at least in part on a vector having the ancillary conditions upheld by the current correction values and a vector having the ancillary conditions upheld by the difference of the current correction values relative to the correction values of the preceding working cycle. The control device determines the manipulated variables for the flatness actuators in consideration of the determined current correction variables.

A metal strip is rolled in a roll stand and a control device for the roll stand determines, by means of a working cycle, a number of manipulated variables for flatness actuators of the roll stand and actuates them accordingly. The control device implements an optimizer, which provisionally sets the current correction values, and determines a totality of flatness values. Then, the optimizer minimizes the relationship by varying the current correction variables. When determining the current correction variables (s), the optimizer considers linear ancillary conditions, based at least in part on a vector having the ancillary conditions upheld by the current correction values and a vector having the ancillary conditions upheld by the difference of the current correction values relative to the correction values of the preceding working cycle. The control device determines the manipulated variables for the flatness actuators in consideration of the determined current correction variables.

Methods and apparatus for locally changing a roll gap in the region of the strip edges (10) of a rolled strip (1) in a rolling stand (2). The roll gap can be changed locally in the region of the strip edges (10) of the strip (1) during the hot rolling. Axial displacement of the working rollers (3, 4) in opposite directions is by a displacement distance s, where s is greater than or less than r/tan() and r indicates the wear of the running surface (8) in the radial direction (R) and indicates the pitch angle of the conical portion (7) of the respective working roller (3, 4).

In a decision control device of a control system, a predetermined pass schedule is decided by adjusting the rolling force per unit width at a last stand of a hot finishing tandem rolling mill to cause the edge profile on the outlet side of the last stand to fall within an allowable range based on the relationship between a strip crown and the edge profile on the outlet side of the last stand with respect to the rolling force per unit width and a strip shape control parameter, obtained regarding the last stand, and adjusting the strip shape control parameter of the last stand to cause the strip shape on the outlet side of the last stand to fall within an allowable range and cause the strip crown to become a predetermined value or smaller.

A method ascertains control variables for active profile and flatness control elements for at least one rolling stand for hot rolling metal strip with a plurality of i=1 . . . I successive passes and for ascertaining profile and center flatness values for the hot-rolled metal strip. The occurrence of fluctuations in the center flatness of the metal strip after the individual passes and the resulting disadvantages for the rolling stability and the product quality are prevented. The method provides that, also for the target center flatness of the metal strip after a predetermined pass k with i=1 . . . <k< . . . I and for the target center flatness after the subsequent passes, pass-specific interval ranges are also specified in each case, and in that the successive calculation of the control variables and profile values is then carried out taking into account such additional specifications as well.

A control device for a rolling mill apparatus including at least one rolling mill stand for rolling a metal plate includes: a detection signal acquisition part for receiving, from an edge crack sensor, a detection signal of an edge crack at an end portion of the metal plate in a plate width direction; and a rolling condition decision part for deciding a rolling condition for the rolling mill apparatus. The rolling condition decision part is configured to change, if the detection signal acquisition part receives the detection signal of the edge crack, the rolling condition for the rolling mill apparatus from a first rolling condition immediately before detection of the edge crack to a second rolling condition which is more capable of suppressing growth of the edge crack than the first rolling condition.