A flatness-measuring device for a hot-rolled strip within a hot-rolling mill includes an entry-side deflection roller and an exit-side deflection roller. A central deflection roller is arranged between the entry-side deflection roller and the exit-side deflection roller. The central deflection roller is used as a flatness-measuring roller. To prevent the hot-rolled strip from departing laterally during a flatness measurement, the flatness-measuring device has a sensing apparatus for sensing an actual position of the hot-rolled strip. An adjusting apparatus is connected to the sensing apparatus and to at least one of the deflection rollers. The flatness-measuring device is designed to vary an angle between a longitudinal central axis of the deflection roller respectively connected to the adjusting apparatus and a longitudinal axis of the flatness-measuring device based on a deviation of the actual position of the hot-rolled strip from a predefined target position.

A method for detecting a faulty cooling unit in a set of cooling units configured to provide a coolant to work rolls arranged to process a work item therebetween, the method including: varying the flow rates of the coolant ejected from a sub-set of the cooling units; in response to varying the flow rates, determining a flatness variation value of the work item for at least each of the cooling units in the sub-set of cooling units, the flatness variation value being indicative of the work item flatness variation downstream of the work rolls; and detecting a faulty cooling unit based on comparing the flatness variation values to a reference flatness variation value.

A method for detecting a faulty cooling unit in a set of cooling units configured to provide a coolant to work rolls arranged to process a work item therebetween, the method including: varying the flow rates of the coolant ejected from a sub-set of the cooling units; in response to varying the flow rates, determining a flatness variation value of the work item for at least each of the cooling units in the sub-set of cooling units, the flatness variation value being indicative of the work item flatness variation downstream of the work rolls; and detecting a faulty cooling unit based on comparing the flatness variation values to a reference flatness variation value.

A method for detecting a faulty cooling unit in a set of cooling units configured to provide a coolant to work rolls arranged to process a work item therebetween, the method including: varying the flow rates of the coolant ejected from a sub-set of the cooling units; in response to varying the flow rates, determining a flatness variation value of the work item for at least each of the cooling units in the sub-set of cooling units, the flatness variation value being indicative of the work item flatness variation downstream of the work rolls; and detecting a faulty cooling unit based on comparing the flatness variation values to a reference flatness variation value.

A method for detecting a faulty cooling unit in a set of cooling units configured to provide a coolant to work rolls arranged to process a work item therebetween, the method including: varying the flow rates of the coolant ejected from a sub-set of the cooling units; in response to varying the flow rates, determining a flatness variation value of the work item for at least each of the cooling units in the sub-set of cooling units, the flatness variation value being indicative of the work item flatness variation downstream of the work rolls; and detecting a faulty cooling unit based on comparing the flatness variation values to a reference flatness variation value.

A control device (3b) for a roll stand (1). During rolling of a metal strip (2) in the roll stand (1), the device receives measurement data (M) for a lateral position (y) of the metal strip (2) on the inlet side and/or outlet side of the roll stand (1). Taking into account parameters (P) of the stand regulator (3a) on the basis of the deviation in the lateral position (y) from a target position (y*), a stand regulator (3a) of the control device (3b) determines a tilt value (δs) for the roll stand (1) and controls the roll stand (1) accordingly. The control device (3b) determines at least one variable (V1, V2, Q1, Q2) from which it is derived, for both strip edges (7, 8) of the metal strip (2), whether the metal strip (2) forms an undulation (9) in the region of the particular strip edge (7, 8). As soon as the metal strip (2) forms an undulation (9) in the region of one of the strip edges (7, 8), the control device (3b) varies at least one of the parameters (P) of the stand regulator (3a), such that the stand regulator (3a) determines the tilt value (δs), starting from the variation in the at least one parameter (P), and taking into account the changed parameter (P).

A control device (3b) for a roll stand (1). During rolling of a metal strip (2) in the roll stand (1), the device receives measurement data (M) for a lateral position (y) of the metal strip (2) on the inlet side and/or outlet side of the roll stand (1). Taking into account parameters (P) of the stand regulator (3a) on the basis of the deviation in the lateral position (y) from a target position (y*), a stand regulator (3a) of the control device (3b) determines a tilt value (δs) for the roll stand (1) and controls the roll stand (1) accordingly. The control device (3b) determines at least one variable (V1, V2, Q1, Q2) from which it is derived, for both strip edges (7, 8) of the metal strip (2), whether the metal strip (2) forms an undulation (9) in the region of the particular strip edge (7, 8). As soon as the metal strip (2) forms an undulation (9) in the region of one of the strip edges (7, 8), the control device (3b) varies at least one of the parameters (P) of the stand regulator (3a), such that the stand regulator (3a) determines the tilt value (δs), starting from the variation in the at least one parameter (P), and taking into account the changed parameter (P).

A control device of the rolling mill line controls actuators of a downstream and an upstream roll stand. The control device determines control variables for the actuators of the upstream roll stand while taking into consideration a flatness change to be carried out and additionally taking into consideration a contour change to be carried out and controls the actuators of the upstream roll stand accordingly. The control device determines control variables for the actuators of the downstream roll stand while taking into consideration the contour change to be performed but without taking into consideration the flatness change to be performed and controls the actuators of the downstream roll stand accordingly. The control device outputs the control variables to the actuators of the downstream roll stand with a delay of a transport time, relative to the corresponding control variables for the actuators of the upstream roll stand.

A control device of the rolling mill line controls actuators of a downstream and an upstream roll stand. The control device determines control variables for the actuators of the upstream roll stand while taking into consideration a flatness change to be carried out and additionally taking into consideration a contour change to be carried out and controls the actuators of the upstream roll stand accordingly. The control device determines control variables for the actuators of the downstream roll stand while taking into consideration the contour change to be performed but without taking into consideration the flatness change to be performed and controls the actuators of the downstream roll stand accordingly. The control device outputs the control variables to the actuators of the downstream roll stand with a delay of a transport time, relative to the corresponding control variables for the actuators of the upstream roll stand.

A rolling mill control system and method includes use of sensors located between rolling mill stands to directly measure metal sheet or plate flatness, thickness profile, position, and the camber of the rolls in the mill. A feedback loop control system adjusts or adapts rolling mill control mechanisms to control the rolling process.