Determining the lateral offset of a metal strip on the basis of the contour of an end face of a coil
Patent Information
- Application Number
- EP2023722862
- Authority / Receiving Office
- EP · EP
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2022-05-05
- Filing Date
- 2023-04-26
- Publication Date
- 2025-03-12
- Estimated Expiration
- 2043-04-26
AI Technical Summary
Existing rolling mill technologies face challenges in accurately determining and addressing the lateral offset of metal strips during rolling, especially when the metal strip is coiled, leading to issues like high walk-up and quality parameter deviations such as profile, flatness, and thickness variations.
A control method that utilizes the contour of the coil's end face to determine the lateral offset of the metal strip before uncoiling, allowing for precise manipulation of the roll gap and other actuators to correct for lateral movements, using detection devices like cameras or laser scanners to provide the control device with necessary information for advanced control algorithms.
This approach enables accurate prediction and correction of lateral offset over the entire length of the metal strip, improving roll quality by reducing lateral migration and its associated defects, and can be implemented with minimal external data dependency.
Smart Images
Figure 1.1
Abstract
Description
[0001] Description
[0002] Title of the invention
[0003] Determination of the lateral offset of a metal strip based on the contour of a coil end face
[0004] field of technology
[0005] The present invention is based on an operating method for a rolling mill which has at least one rolling stand and a pay-off device arranged upstream of the rolling stand,
[0006] - whereby in the rolling mill a metal strip wound into a coil is unwound from the uncoiler, from there it is fed to the rolling stand and is rolled in the rolling stand,
[0007] - wherein a control device for the rolling stand determines a respective actuating variable for at least one actuator assigned to the rolling stand using a respective lateral offset which a respective section of the metal strip has at a predetermined distance in front of the rolling stand and controls the actuator in accordance with the respective actuating variable determined.
[0008] The present invention is further based on a control program for a control device of a rolling stand for rolling a metal strip, wherein the control program comprises machine code that can be processed by the control device, wherein the processing of the machine code by the control device causes the control device to be operated in accordance with such an operating method.
[0009] The present invention further relates to a control device for a rolling stand of a rolling mill, wherein the control device is programmed with such a control program that the control device executes such a control program during operation. The present invention further relates to a rolling mill comprising at least one rolling stand, a pay-off reel arranged upstream of the rolling stand, and a control device for the rolling stand.
[0010] State of the art
[0011] Such an operating method is known, for example, from DE 34 13 269 C2.
[0012] Summary of the invention
[0013] When rolling a metal strip, the rolled metal strip often migrates laterally, meaning it migrates in the width direction of the metal strip. Such migrates can occur both at the entry and exit sides of a rolling stand. Consequently, in a multi-stand rolling mill, it can also occur between the individual stands of the rolling mill.
[0014] Small lateral movements are often unproblematic. However, larger lateral movements can cause the metal strip to collide with a lateral guide, resulting in a so-called "walkover." Furthermore, lateral movements affect quality parameters of the rolled metal strip, such as the profile, flatness, and thickness wedge. This also applies to small lateral movements of the metal strip.
[0015] It is known in the prior art to detect the lateral offset of the metal strip on the exit side of the rolling stand—for example, using a camera—and to adjust a control variable for an actuator of the rolling stand depending on the offset detected on the exit side. Purely by way of example, reference can be made to EP 3 202 502 A1. It is also already known to detect the lateral offset of the metal strip on the entry side of the rolling stand and to adjust a control variable for an actuator of the rolling stand depending on the offset detected on the entry side. Purely by way of example, reference can be made to the aforementioned DE 34 13 269 C2.
[0016] In DE 34 13 269 C2, the lateral offset of each individual section of the metal strip is recorded on the inlet side of the rolling stand and used within the framework of a conventional control system (e.g. a proportional control system).
[0017] The procedure of DE 34 13 269 C2 is only practical if the metal strip is in the form of a flat metal strip, i.e. not in the coiled state of the metal strip.
[0018] The object of the present invention is to create possibilities by means of which the lateral offset of a respective section of the metal strip can be taken into account even if the metal strip is wound into a coil and is unwound in the rolling stand before the metal strip is rolled.
[0019] The object is achieved by an operating method having the features of claim 1. Advantageous embodiments of the operating method are the subject of dependent claims 2 to 4.
[0020] According to the invention, an operating method of the type mentioned at the outset is designed in that the control device is provided with a one-time contour of at least one end face of the coil still being wound on the coil before the metal strip is unwound, so that the control device already has the information for the lateral offset of the sections over the entire length of the metal strip available before the metal strip is fed to the rolling stand, and that the control device determines the respective lateral offset using the contour.
[0021] The actuator can, in particular, be an actuator by means of which an asymmetric adjustment of the roll gap can be carried out. This can directly influence the lateral strip travel. A typical example of such an actuator is a wedge adjustment of the roll gap. Alternatively or additionally, however, control variables for other actuators can also be determined, in particular for actuators which only influence the profile and flatness of the metal strip locally or globally but symmetrically. A typical example of an actuator with only a local effect is a cooling device which, viewed in the width direction of the metal strip, only acts on a single section of a work roll. A typical example of an actuator with a global but symmetrical effect is a roll bend. Another typical example is a roll shift.
[0022] In the simplest case, the control variable is determined using a standard setpoint-actual value control, for example, using a P controller, a PI controller, or a PID controller. However, since the contour of the end face already determines the course of the lateral offset along the entire length of the metal strip, more complex control systems are also possible, such as model-predictive control. Furthermore, other predictive consideration of the course of the lateral offset is also possible. For example, an offline optimization of the control variable can be performed in advance along the entire length of the strip.
[0023] As a rule, the control device only knows the contour of a single end face of the coil. In this case, the control device can only determine the lateral offset - assuming that the width of the metal strip is constant along its length. Alternatively, however, it is also possible for the control device to know the contours of both end faces of the coil. In this case, the control device can not only determine the respective lateral offset, but also, for example, determine the respective width of the metal strip for each individual section of the metal strip and take this into account when controlling the rolling stand. This is particularly advantageous if the width of the metal strip can be influenced using the actuator.In particular, in this case, the actuator may be an actuator of the rolling stand as such or an actuator assigned to the rolling stand, for example a looper arranged upstream or downstream of the rolling stand or an edger arranged upstream or downstream of the rolling stand.
[0024] In principle, the contour of the end face can be detected at any time after the metal strip has been wound onto the coil, in particular immediately after coiling or at another time between coiling and feeding to the payoff. However, the contour of the end face is preferably detected by a detection device assigned to the payoff while the coil is already in the payoff, and then fed to the control device. This reduces the dependence of the operating method on externally supplied or provided data.
[0025] The detection device can, for example, be a thermal imaging camera or a camera that works with light in the visible range, by means of which conventional two-dimensional images are captured. It can also be a camera by means of which depth images are captured. It is also possible to design the detection device as a laser scanner, by means of which the contour of the end face is scanned. Other designs are also possible. All of the aforementioned types of detection devices are generally known to those skilled in the art. In a preferred embodiment of the operating method, the contour of the end face of the coil is made known to the control device in the form of a contour line that runs from radially inside to radially outside, based on the end face of the coil. The contour line thus indicates the lateral position of the detected strip edge as a function of the distance from the eye of the coil.In this case, the control device determines the respective lateral offset using the contour line.
[0026] Alternatively, the contour of the coil end face may be made known to the control device in the form of a two-dimensional contour surface relative to the coil end face. In this case, direct use of the two-dimensional contour surface is of course possible. Preferably, however, the control device uses the contour surface to determine a contour line running from the radial inside to the radial outside relative to the coil end face, and further determines the respective lateral offset using the contour line, but not the two-dimensional contour surface as such. As before, the contour line indicates the lateral position of the detected strip edge as a function of the distance from the coil eye.
[0027] By using the contour line, the computational effort required to determine the respective lateral offset is reduced considerably.
[0028] Based on the contour line, the control device initially knows the offset of each section of the metal strip at a current coil radius (= current location on the radial contour line). This location corresponds to a support point in the longitudinal direction of the metal strip. The distance to the next support point is given by the current coil radius (multiplied by the factor 2n). The new coil radius is given by the current coil radius and the thickness of the coiled metal strip. When the working direction is from outside to inside, the coil radius decreases, i.e. the thickness of the coiled metal strip is subtracted. When the working direction is from inside to outside, the coil radius increases, i.e. the thickness of the coiled metal strip is added. Thus, the control device only knows the offset of the corresponding sections of the metal strip at support points that follow one another in the longitudinal direction of the strip thanks to the contour line.The support points are not equidistant because the coil radius varies. However, this is of secondary importance.
[0029] It is possible for the sections of the metal strip to be defined as such by the support points, thus creating a 1:1 mapping. Alternatively, however, it is also possible to perform interpolation as needed. The interpolation can be linear or nonlinear, as required.
[0030] Within the scope of the operating method according to the invention, the metal strip can be cold-rolled or hot-rolled in the rolling mill as required. In particular, for hot rolling, the rolling mill can be designed, for example, as a Steckel mill. In cold rolling, however, the rolling mill can be the frontmost rolling stand of a tandem mill.
[0031] The object is further achieved by a control program having the features of claim 5. According to the invention, the processing of the control program by the control device causes
[0032] - that before the metal strip is unwound from a decoiler arranged upstream of the rolling stand, the control device is provided with a one-time information about the contour of at least one end face of the coil still being wound up, so that the control device has access to the information for a lateral offset, which sections of the metal strip have at a predetermined distance in front of the rolling stand, over the entire length of the metal strip,
[0033] - that the control device determines the respective lateral offset for the sections using the contour and - that the control device determines a respective actuating variable for at least one actuating element assigned to the rolling stand using the respective lateral offset and controls the actuating element in accordance with the respective actuating variable determined.
[0034] The control program can also be designed in an advantageous manner. The design of the control program corresponds to the advantageous design of the operating method. The same applies to the advantages achieved thereby.
[0035] The object is further achieved by a control device having the features of claim 8. According to the invention, the control device is programmed with a control program according to the invention, so that the control device executes the control program according to the invention during operation.
[0036] The object is further achieved by a rolling mill having the features of claim 9. According to the invention, in a rolling mill of the type mentioned at the outset, the control device is designed as a control device according to the invention.
[0037] Preferably, the uncoiler is assigned a detection device by means of which the contour of the end face is detected while the coil is already in the uncoiler and is then fed to the control device. As a result, the operation of the rolling mill according to the invention is tied to a lesser extent to externally supplied or provided data.
[0038] The rolling mill stand of the rolling mill can be designed as a hot rolling mill or a cold rolling mill, as required. In the former case, the rolling mill can, in particular, be designed as a Steckel mill. In the latter case, the rolling mill stand can, in particular, be the frontmost rolling mill stand of a multi-stand tandem mill. Brief description of the drawings
[0039] The above-described properties, features, and advantages of this invention, as well as the manner in which they are achieved, will become clearer and more readily understood in connection with the following description of the embodiments, which are explained in more detail in conjunction with the drawings. Herein, in schematic representation:
[0040] FIG 1 a rolling mill,
[0041] FIG 2 another rolling mill,
[0042] FIG 3 a flow chart,
[0043] FIG 4 is a section along a line IV-IV in FIGS 1 and 2,
[0044] FIG 5 a flow chart,
[0045] FIG 6 a perspective view of an end face of a coil and
[0046] FIG 7 a flow chart.
[0047] Description of the embodiments
[0048] According to FIG 1, a rolling mill has a rolling stand 1. Only the work rolls of the rolling stand 1 are shown. In the embodiment according to FIG 1, the rolling stand 1 is the only rolling stand in the rolling mill. A payback device 2 is arranged upstream of the rolling stand 1. A coil 3, i.e. a wound metal strip 4, is wound from the payback device 2. The wound metal strip 4 is fed from the payback device 2 to the rolling stand 1. The metal strip 4 is rolled in the rolling stand 1. The coil 3 can have been fed to the payback device 2 as such, i.e. as the metal strip 4 previously wound up in another way. Alternatively, the metal strip 4 can have been wound into the coil 3 by the payback device 2 itself before being wound.
[0049] In the embodiment according to FIG. 1, a coiler 5 is arranged downstream of the rolling stand 1. The metal strip 4 is coiled by the coiler 5 after rolling in the rolling stand 1. As a rule, the operation of a rolling mill according to FIG. 1 takes place in such a way that the metal strip 4 is rolled in reverse in the rolling stand 1, i.e., end pieces of the metal strip 4 are not rolled. The payoff reel 2 and the coiler 5 therefore change their respective functions with each rolling pass. In particular, in such an embodiment, the metal strip 4 is alternately coiled and then uncoiled again by one and the same coiler 2, 5.
[0050] The rolling mill according to FIG. 1 can, in particular, be designed as a Steckel mill. In a Steckel mill, the metal strip 4 is hot-rolled. In this case, the rolling stand 1 is designed as a hot-rolling stand. However, hot-rolling of the metal strip 4 is also possible with other rolling mill configurations. For example, hot-rolling of the metal strip 4 can also take place in a multi-stand hot-rolling mill, in which the uncoiler 2 is arranged upstream of the hot-rolling mill. In a rolling mill configuration as shown in FIG. 1, the rolling stand 1 can also be a roughing stand.
[0051] FIG. 2 shows an alternative design of a rolling mill. According to FIG. 2, the rolling mill has additional rolling stands 6 in addition to the rolling stand 1. In this case, the rolling stand 1 is the frontmost rolling stand of a multi-stand rolling mill. Similar to FIG. 1, only the work rolls of the rolling stands 1 and 6 are shown.
[0052] In the configuration shown in FIG. 2, a payoff device 2 is also arranged upstream of the rolling stand 1. A coil 3, i.e., a previously wound metal strip 4, is fed to the payoff device 2. The metal strip 4 is unwound from the payoff device 2 and from there fed to the rolling stand 1 (and subsequently to the other rolling stands 6). The metal strip 4 is rolled in the rolling stand 1 (and also in the other rolling stands 6).
[0053] As already mentioned, hot rolling of the metal strip 4 can also occur in the configuration shown in FIG. 2. However, according to FIG. 2, an S-roll set 7 is arranged between the uncoiler 2 and the rolling stand 1. Such a configuration is particularly common in a multi-stand tandem mill in which cold rolling of the metal strip 4 occurs. However, cold rolling of the metal strip 4 is also possible in other configurations of the rolling mill.
[0054] In both the rolling mill according to FIG. 1 and the rolling mill according to FIG. 2, at least the rolling stand 1 (usually the entire rolling mill) is controlled by a control device 8. The control device 8 is programmed with a control program 9 so that the control device 8 executes the control program 9 during operation. The control program 9 comprises machine code 10 which can be processed by the control device 8. The processing of the machine code 10 by the control device 8 causes the control device 8 to operate at least the rolling stand 1 - as already mentioned: usually the entire rolling mill - according to an operating method which is explained in more detail below in connection with FIG. 3.
[0055] According to FIG. 3, in a step S1, the control device 8 receives information about a contour K of at least one of the two end faces 11 of the coil 4. It is also possible for the control device 8 to receive information about the contours K of both end faces 11 of the coil 4 in step S1. However, the contour K of one of the two end faces 11 is generally sufficient. This case will therefore be assumed below. Step S1 is performed by the control device 8 before the metal strip 4 is unwound.
[0056] In a step S2, the control device 8 determines a respective lateral offset V for sections i (i = 1, 2, 3, ...) of the metal strip 4. The respective offset V can therefore vary across the sections i. The offset V corresponds, in the width direction of the metal strip 4, to the deviation of the center line of the metal strip 4 from the center line of the rolling stand 1. The offset V of the respective section i is determined for a predetermined distance that the respective section i has from the rolling stand 1. The offset V is determined using the contour K.
[0057] The predetermined distance can be determined as needed. In particular, it can be the location at which the metal strip 4 separates from the remaining part of the coil 3. This determination of the predetermined distance can be particularly useful if there are no devices between the uncoiler 2 and the rolling stand 1 that influence or hinder lateral movements of the metal strip 1. However, it can also be a different location. For example, in the case of the embodiment of FIG. 2, the predetermined distance can be determined by the location of the S-roll set 7. Which location is chosen depends on the circumstances of the individual case.
[0058] In a step S3, the control device 8 determines a respective manipulated variable C for at least one actuator 12. The actuator 12 can be an actuator of the roll stand 1 as such, for example, act locally or globally on the roll gap. Alternatively, the actuator 12 can be arranged upstream or downstream of the roll stand 1. The determination of the respective manipulated variable C applies to the respective section i of the metal strip 4. The respective manipulated variable C is determined by the control device 8 using the respective lateral offset V. Suitable actuators 12, suitable manipulated variables C and suitable determination methods are known to those skilled in the art. In a step S4, the control device 8 controls the actuator 12 according to the determined respective manipulated variable C.
[0059] Step S1 is performed only once, namely once before the metal strip 4 is fed to the rolling stand 1. Step S4 is performed iteratively, repeatedly, namely for a single section i of the metal strip 4. Steps S2 and S3 can be performed either only once or repeatedly iteratively. The procedure adopted for steps S2 and S3 is at the discretion of the person skilled in the art. It will often be advantageous to perform step S2 together with step S1, i.e., once beforehand, and to perform step S3 together with step S4, i.e., repeatedly iteratively.
[0060] The manner in which the contour K of the end face 11 becomes known to the control device 8 can be determined as required. For example, it is possible for the contour K to be specified to the control device 8 by an operator or by a higher-level control device. Preferably, however, a detection device 13 is assigned to the uncoiler 2, by means of which the contour K of the end face 11 is detected while the coil 3 is already located in the uncoiler 2. In this case, the detection device 13 feeds the detected contour K to the control device 8. The control device 8 receives the detected contour K from the detection device 13. In this way, the contour K becomes known to the control device 8.
[0061] In the following, in conjunction with FIGS. 4 and 5, a preferred manner is determined in which the contour K can be made available to the control device 8.
[0062] FIG 4 shows a section along a line IV-IV in FIGS 1 and 2. According to FIG 4, the coil 3 has a coil eye 14.
[0063] The coil eye 14 has a diameter D1. RI = D1 / 2 is therefore the minimum radius of the coil 3. The coil 3 also has an outer diameter D2. R2 = D2 / 2 is therefore the maximum radius of the coil 3. The metal strip 4 has a thickness d. The individual turns 15 of the coil 3 are spaced from one another in the radial direction of the coil 3 (i.e., viewed from the inside outward or, conversely, from the outside inward) by the thickness d of the metal strip 4. Furthermore, the individual turns 15 of the coil 3 are slightly offset from one another laterally (i.e., viewed in the width direction of the metal strip 4). The contours K of the end faces 11 follow the slight lateral offset of the turns 15.Viewed along the section line IV-IV (see FIGS. 1 and 2), a contour line KL is thus obtained with respect to the corresponding end face 11 of the coil 3, which describes the offset of the windings 15 as a function of the current coil radius r in the range from RI to R2, i.e., from radially inside to radially outside (or vice versa). A completely analogous contour line KL would also result if the section line through the coil 3 were positioned differently.
[0064] According to FIG 5, it is possible for the control device 8 to receive the contour K of the end face 11 of the coil 3 in a step S11 in the form of such a contour line KL.
[0065] The location of the outermost turn 15 corresponds to the beginning of the metal strip 4. The value of the contour line KL at this point corresponds to the offset of the foremost section i=l of the metal strip 4. The radius r for the next inner turn 15 can be easily determined by subtracting the thickness d of the metal strip 4 from the radius r. At this point on the metal strip 4, the contour line KL can be evaluated again by the control device 8. This procedure can be repeated successively for all turns 15 of the metal strip 4. Thus, in a step S12, the control device 8 can gradually determine the lateral offset of the metal strip 4 at this point for all turns 15 and thus for support points that are spaced from one another by a distance of 2nr (where the current coil radius r is variable). This results in a functional course for the lateral offset of the metal strip 4 over the entire length of the metal strip 4.Using this offset, the lateral offset V for sections i can be easily determined.
[0066] In the simplest case, the segments i are determined by the sampling points. In this case, the segments i are not of equal size. If the segments i should be of equal size or meet another criterion, interpolation between neighboring sampling points can be performed as needed.
[0067] The steps S11 and S12 thus correspond to a possible implementation of the steps S1 and S2 of FIG 3.
[0068] In the following, in conjunction with FIGS. 6 and 7, a further preferred manner is determined in which the contour K can be made available to the control device 8.
[0069] FIG. 6 shows a perspective view of an end face 11 of the coil 3. Using suitable detection devices 13, it is readily possible to determine a contour surface KF, which reflects, so to speak, the three-dimensional "offset mountain range" over the entire end face 11. For example, if the detection device 13 is designed as a laser scanner, a two-dimensional scanning of the entire end face 11 can be performed. However, other approaches are also possible.
[0070] According to FIG. 7, it is possible for the control device 8 to receive the contour K of the end face 11 of the coil 3 in the form of such a contour surface KF in a step S21. In this case, the control device 8 can, for example, determine a contour line KL based on the contour surface KF in a step S22. In particular, the control device 8 can select and evaluate a narrow strip of the contour surface KF running from radially inside to radially outside. In a step S23, the control device 8 can then determine the respective lateral offset V of the sections i using the contour line KL. The contour surface KF itself is no longer required for the execution of step S23. Thus, step S23 of FIG. 7 can correspond in content, in particular, to step S12 of FIG. 5. Steps S21 to S23 thus correspond to a further possible implementation of steps S1 and S2 of FIG. 3.
[0071] The present invention offers many advantages. By detecting the contour K of an end face 11, the information for the lateral offset V of the sections i is readily available over the entire length of the metal strip 4. This allows, in particular, superior control algorithms to be implemented. By detecting directly at the uncoiler 2, independent detection is achieved that is not dependent on external inputs. Furthermore, it is ensured that effects that occur before uncoiling are reliably detected and taken into account. The solutions according to the invention are simple, robust, and reliable and can also be retrofitted to existing rolling mills.
[0072] Although the invention has been illustrated and described in detail by the preferred embodiment, the invention is not limited by the disclosed examples and other variants can be derived therefrom by those skilled in the art without departing from the scope of the invention.
[0073] List of reference symbols
[0074] 1 rolling stand
[0075] 2 unwinders
[0076] 3 coils
[0077] 4 metal band
[0078] 5 On reel
[0079] 6 additional rolling stands
[0080] 7 S-roller set
[0081] 8 Control device
[0082] 9 Control program
[0083] 10 Machine code
[0084] 11 front sides
[0085] 12 Actuator
[0086] 13 Recording device
[0087] 14 Coil eye
[0088] 15 turns
[0089] C Control variable
[0090] Dl, D2 Diameter d Strip thickness i Sections of the metal strip
[0091] K Contour
[0092] KF contour surface
[0093] KL contour line
[0094] RI, R2, r radii
[0095] S1 to S23 steps
[0096] Offset
Claims
Claims 1. Operating procedure for a rolling mill comprising at least one rolling stand (1) and a reel (2) upstream of the rolling stand (1), - wherein in the rolling mill a metal strip (4) wound into a coil (3) is unwound from the uncoiler (2), from there fed to the rolling stand (1) and rolled in the rolling stand (1), - wherein a control device (8) for the rolling stand (1) determines a respective control variable (C) for at least one actuator (12) assigned to the rolling stand (1) by utilizing a respective lateral offset (V) that a respective section (i) of the metal strip (4) has at a predetermined distance in front of the rolling stand (1) and controls the actuator (12) according to the determined respective control variable (C), characterized in that the control device (8) is informed once of a contour (K) of at least one end face (11) of the coil (3) still wound onto the metal strip (4) before the metal strip (4) is unwound, so that the control device (8) already has the information for the lateral offset (V) of the sections (i) over the entire length of the metal strip (4) available before the metal strip (4) is fed to the rolling stand (1), and that the control device (8) determines the respective lateral offset (V) by utilizing the contour (K) determined.
2. Operating method according to claim 1, characterized in that the contour (K) of the end face (11) is detected by means of a detection device (13) associated with the unwinder (2), while the coil (3) is already in the unwinder (2), and is then fed to the control device (8).
3. Operating method according to claim 1 or 2, characterized by , - that the contour (K) of the end face (11) of the coil (3) is known to the control device (8) in the form of a contour line (KL) extending from radially inside to radially outside with respect to the end face (11) of the coil (3) and that the control device (8) determines the respective lateral offset (V) using the contour line (KL) or - that the contour (K) of the end face (11) of the coil (3) is known to the control device (8) in the form of a two-dimensional contour surface (KF) with respect to the end face (11) of the coil (3), that the control device (8) determines a contour line (KL) extending from radially inside to radially outside with respect to the end face (11) of the coil (3) on the basis of the contour surface (KF), and that the control device (8) determines the respective lateral offset (V) using the contour line (KL), but not the two-dimensional contour surface (KF) as such.
4. Operating method according to claim 1, 2 or 3, characterized in that the metal strip (4) is cold or hot rolled in the rolling stand (1).
5. Control program for a control device (8) of a rolling stand (1) for rolling a metal strip (4), wherein the control program comprises machine code (10) executable by the control device (8), wherein the execution of the machine code (10) by the control device (8) is effected, - that the control device (8) is informed once, before the metal strip (4) is unwound from a unwinder (2) located upstream of the rolling stand (1), of a contour (K) of at least one end face (11) of the coil (3) still wound onto the roll, so that the control device (8) has the information for a lateral offset (V) that sections (i) of the metal strip (4) have at a predetermined distance in front of the rolling stand (1) over the entire length of the metal strip (4), - that the control device (8) determines the respective lateral offset (V) for the sections (i) using the contour (K) and - that the control device (8) determines a respective actuating variable (C) for at least one actuator (12) assigned to the rolling stand (1) by taking into account the respective lateral offset (V) and controls the actuator (12) according to the determined respective actuating variable (C).
6. Control program according to claim 5, characterized in that the execution of the machine code (10) by the control device (8) causes the control device (8) to receive the contour (K) of the end face (11) from a detection device (13) associated with the unwinder (2), while the coil (3) is already in the unwinder (2).
7. Control program according to claim 5 or 6, characterized in that the execution of the machine code (10) is effected by the control device (8), - that the control device (8) receives the contour (K) of the end face (11) of the coil (3) in the form of a contour line (KL) extending from radially inside to radially outside with respect to the end face (11) of the coil (3) and determines the respective lateral offset (V) using the contour line (KL) or - that the control device (8) receives the contour (K) of the end face (11) of the coil (3) in the form of a two-dimensional contour surface (KF) relative to the end face (11) of the coil (3) and determines a contour line (KL) extending from radially inside to radially outside relative to the end face (11) of the coil (3) based on the contour surface (KF) and determines the respective lateral offset (V) using the contour line (KL), but not the two-dimensional contour surface (KF).
8. Control device for a rolling stand (1) of a rolling plant, wherein the control device is programmed with a control program (9) according to claim 5, 6 or 7, such that the control device executes the control program (9) during operation.
9. Rolling mill comprising at least one rolling stand (1), a reel (2) arranged upstream of the rolling stand (1) and a control device (8) for the rolling stand (1), characterized in that the control device (8) is designed as a control device according to claim 8.
10. Rolling mill according to claim 9, characterized in that a detection device (13) is assigned to the uncoiler (2) by means of which the contour (K) of the end face (11) is detected while the coil (3) is already in the uncoiler (2) and is then fed to the control device (8).
11. Rolling mill according to claim 9 or 10, characterized in that the rolling stand (1) is designed as a hot rolling stand, in particular the rolling mill is designed as a Steckelmill, or that the rolling stand (1) is designed as a cold rolling stand, in particular as the foremost rolling stand of a multi-stand tandem mill.