METHOD FOR PRODUCING METAL STRIPS

Abstract

A method for producing metal strip in a rolling mill, so that as a result of a more accurate manufacturing of metal strips in the future, a more precise forecasting of the profile contour of the metal strip can be obtained over the width of the metal strip, as well as a more precise setting of the profile actuator of the rolling mill. A forecast value is calculated for the profile contour within the context of the simulation of the rolling process before the rolling of the metal strip. In contrast to that, the calculation in the simulation is not conducted prior to the rolling, but instead it is obtained by a post-calculation after the rolling of the metal strip has been carried out.

Claims

1-24. (canceled)

25. A method for producing metal strips in a rolling mill with a desired profile contour, comprising the following steps: a) presetting a target value for the profile contour for at least one reference position bi in the width direction for at least one nth metal strip; b) simulating a rolling process on the rolling line for producing the metal strips with the aid of a process model, wherein the setting values for profile actuators and a forecast value CP(n)bi for the profile contour of the nth metal strip are calculated at the reference position bi, which reaches the target value as closely as possibleas long as it is availablewhile taking into consideration old adaptation values at the reference position bi and with potential restrictions; c) setting the profile actuators with the calculated setting values; d) rolling the nth metal strip; e) measuring the actual value Cactual(n)bi of the profile contour of the rolled nth metal strip at the reference position bi; and f) determining a new adaptation value C(n)bi on the basis of the difference between the actual value Cactual(n)bi and the forecast value CP(n)bi recalculated for the profile contour of the nth metal strip at the reference position bi; wherein the steps a), b) and c) are carried out before the rolling of the at least nth metal strip for a plurality, wherein |2, of reference positions bi, wherein 1i|, in at least one width section of the at least nth metal strip; wherein the steps e) and f) are carried out after the rolling of the at least nth metal strip for the plurality | of reference positions bi in order to determine the new adaptation value C(n)bi at the plurality | of the reference positions bi in the at least one width section of the at least nth metal strip; and g) wherein during a subsequent production of a further longitudinal section of the nth metal strip or of an n+xth metal strip, wherein x=1, 2, etc., at least the steps a) through d) are repeated with n=n+x, wherein the new adaptation values C(n)bi determined previously according to step f) at least for the nth metal strip are taken into account for the plurality | of the reference positions bi during the calculation of the settings for the profile actuator and for the calculation of the forecast values according to step b) for the n+xth metal strip as old adaptation values.

26. The method according to claim 25, wherein the determination of the new adaptation value C(n)bi according to step f) at the reference positions bi of the nth metal strip is carried out at least partially in the form of a short-term adaptation value CK(n)bi according to the following formula:
C(n)bi=CK(n)bi=CK(nx)bi+[Cactual(n)biCP(n)bi] wherein K: short-term adaptation, x=1, 2, 3 . . . ; CK(nx)bi: old short-term adaptation value; Cactual(n)bi: measured actual value for the profile contour of the nth metal strip at the reference position bi; and CP(n)bi: calculated forecast value or calculated strip profile.

27. A method for producing metal strips in a rolling mill with a desired profile contour, provided with the following steps: a) presetting a target value for the profile contour for at least one reference position bi in the width direction for at least one nth metal strip; b) simulating a rolling process on the rolling line for producing the metal strips with the aid of a process model, wherein the setting values for profile actuatorsas long as they are available while taking into account all adaptation value at reference positions bi and possible restrictionsare calculated in such a way that the target value is achieved as much as possible; d) adjusting the profile actuators with the calculated adjustment values; d) rolling the nth metal strip; e) measuring the actual value Cactual(n)bi of the profile contour of the rolled nth metal strip at the reference position bi; e) calculating a recalculated forecast value CP(n)bi for the profile contour of the nth metal strip at the reference position bi on the basis of the rolling mill conditions and current processing positions, as they were present during the rolling of the nth metal strip according to step d); and f) determining a new adaptation value C(n)bi on the basis of the difference between the actual value Cactual(n)bi and the forecast value CP(n)bi recalculated for the profile contour of the nth metal strip at the reference position bi; wherein the steps a), b) and c) are carried out before the rolling of the at least nth metal strip for a plurality |, wherein |2, of reference positions bi, wherein 1|, in at least one width section of the at least nth metal strip; wherein the steps e), e) and f) are carried out after the rolling of the at least nth metal strip for the plurality | of reference positions bi in order to determine the new adaptation value C(n)bi at the plurality | of the reference positions bi in the at least one width section of the at least nth metal strip; and g) wherein during a subsequent production of a further longitudinal section of the nth metal strip or of an n+xth metal strip, wherein x=1, 2, etc., at least the steps a) through d) are repeated with n=n+x, wherein the new adaptation values C(n)bi determined previously according to step f) at least for the nth metal strip are taken into account for the plurality | of the reference positions bi during the calculation of the settings for the profile actuator and for the calculation of the forecast values according to step b) for the n+xth metal strip as old adaptation values.

28. The method according to claim 27, wherein the determination of the new adaptation value C(n)bi according to step f) at the reference positions bi of the nth metal strip is carried out at least partially in the form of a short-term adaptation value CK(n)bi according to the following formula:
C(n)bi=CK(n)bi=CK(nx)bi+[Cactual(!n)biCP(n)bi] wherein K: short-term adaptation, x=1, 2, 3 . . . ; CK(nx)bi: old short-term adaptation value; Cactual(n)bi: measured actual value for the profile contour of the nth metal strip at the reference position bi; and CP(n)bi: measured recalculated forecast value or strip profile to be recalculated.

29. The method according to claim 27, wherein the determination of new adaptation value C(n)bi according to claim f) in claim 1 or 3 at the reference positions bi is carried at least partially in the form of long-term adaptation values CL(n)bi by carrying out the following steps: determining the adaptation values by repeating the steps a) through f) according to claim 1 or 3 at a plurality | of reference positions bi for a plurality of metal strips of an adaptation group processed by rolling before the n+xth metal strip; and calculating the long-term position values CLbi with the formation of average values of the adaptation values, or with the formation of average values of the differences between the actual values and forecast values for the profile contour for the plurality of metal strips, in each case at a reference position bi.

30. The method according to claim 26, wherein determination of the adaptation value C(n)bi according to step f) in the form of the sum adaptation value CS(n)bi as a sum of the short-term adaptation value CK(nbi) and the long term adaptation value CL(nbi) to be used for the metal strip n+x.

31. The method according to one of the claim 26, wherein determination of the adaptation value C(nbi) according to step f) and or the use of the adaptation value C(nbi) in the form of a short-term adaptation value weighted with the weighting factor g, wherein 0g1, or with the weighting function weighted for the short-term adaptation value, long-term adaptation value, or sum adaptation value.

32. The method according to claim 25, wherein determination of an adaptation contour C(n+x)m for the n+xth metal strip in the form of an attachment function, which is preferably conducted via an adaptation value determined at the at least one metal strip at at least two reference positions bi and preferably additionally via at least one other calculation pointby means of a calculated/predetermined calculation pointat at least one further strip width position m.

33. The method according to claim 32, wherein determination of an adapted profile contour CP(n+x)m for the n+xthe metal strip by the addition of a non-adapted calculated profile contour CP(n+x)moAforecast by the process modelfor the n+xth metal strip and the calculation adaptation contour C(n+x)m for the xth metal strip.

34. The method according claim 32, wherein the determination of the adaptation contour or of the profile contour for 2 width sections of the metal strip is carried out, wherein the first width section of the metal strip is located for example in the central region and the second width section or other width sections are located for example in the edge region of the metal strip.

35. The method according to claim 34, wherein in the case when two sections adjoin each other in the width direction, the adaptation contour or the adapted profile contour is preferably selected over the two width sections in such a way that the contour courses can be continuously differentiated at the boundary of one strip section to another strip section, in particular in that they have the same gradients.

36. The method according to claim 34, wherein the attachment function is formed over at least one of the width sections from a linear function, a polynomial function, an exponential function, a trigonometric function, a spline function or a combination of different functions.

37. The method according to claim 36, wherein the attachment functions are different for the difference adjacent width sections.

38. The method according to claim 32, wherein the adaptation contour or the adapted profile contour is extrapolated into a neighboring width section over a width section in order to determine an extrapolated adaptation contour or an extrapolated adapted profile contour over the neighboring width region.

39. The method according to claim 25, wherein instead of the measured actual value Cactual(n)bi of the profile contour of the metal strip, an average value is used at the reference position bi from the actual value measured at the mirror-like reference position bi on the right and left half of the metal stripseen in the direction of rolling.

40. The method according to one of the claim 25, wherein the forecast value CP(n+x)bi or/and the adapted profile contour CP(n+x)m is first determined for one strip half, for example the strip half on the operating side, and after that it is mirrored for the other strip half, for example on the drive side, at the strip center level, which extends in the longitudinal direction.

41. The method according to claim 25, wherein the measured actual value Cactual(n)bi of the profile contour is used as a direct measured value at the reference position bi or as a smoothed profile measurement value via an attachment function.

42. The method according to claim 33, wherein the adapted profile contour CP(n+x)m is analyzed with regard to profile anomalies, such as strip beads or steep edge drops, in particular in the edge region of the metal strip.

43. The method according to claim 42, wherein when calculated strip beads of the adapted profile contour CP(n+x)m are present, they are iteratively improved by means of the process model by successively increasing a value of the profile contour at at least one of the reference positions bi within the scope of the allowable profile positioning limits and by means of corresponding new setting of the profile actuators in order to reduce the strip bead.

44. The method according to claim 42, wherein the calculated strip beads are reduced or avoided by increasing the load in the last rolling frame (discharge frame), or in the last rolling frame of a rolling line, or with the last rolling passes of a frame in the rolling mill by redistributing the load from the front to the rear, or by deselecting at least one rolling frame or rolling pass within the scope of the process and facility limits.

45. The method according to claim 34, wherein for the production of the n+xthe metal strip, the profile actuators are adjusted in step b) in such a way that the target values predetermined for a plurality of reference positions bi or calculated forecast values CP(n+x)bi for the profile contour are achieved in minimum or maximum profile boundaries; or the profile actuators are adjusted in such a way in step b) that the target value predetermined for a reference position bi is achieved, or the deviation from the target value is minimal and at the same time, the strip profile is maintained within allowable minimum or maximum profile values at at least one further strip width position.

46. The method according to claim 25, wherein the determined adaptation value at the positions bi and/or the adapted profile contour and/or the adaptation contour in the process model are taken into accounttransmitted in particular to the previous rolling passes or frames with weighting factors or transmission functionsfor the calculation of the intermediate frameor intermediate contours of the front frames or the preceding passes and for an optimized adjustment of the profile actuators.

47. The method according to claim 25, wherein the reference position bi is defined via its distance from the edge of the metal strip.

48. The method according to claim 25, wherein for the adjustment of the target contour, while using the strip contour adaptation, the following profile actuators are employed: variable processing cooling systems, or zone cooling system, or local roller warming for influencing the thermal crown and/or processing of rolling shifts in conjunction with roller grinding (special roller grinding used to combat strip beads or strip edge drop, tapered roll, CVC rollers, CVC rollers with grinding on a higher level, or polynomial nth level or trigonometric functions), heating systems for the strip edges, strip zone cooling systems, bending systems for the work rollers and/or frames with rollers provided with the pair cross function.

Description

[0065] A total of 5 figures are attached to the description, wherein

[0066] FIG. 1 shows the profile contour of a metal strip used to facilitate understanding of the definition of the essential terms in this invention;

[0067] FIGS. 2.1, 2.2 and 2.3 show illustrations of the method according to the invention;

[0068] FIG. 3 shows a first possibility for reducing an undesirable bead at the edge of the metal strip profile based on method according to the invention;

[0069] FIGS. 4.1 and 4.2 show a second possibility for reducing an undesirable bead at the edge of the metal strip; and

[0070] FIG. 5 shows the adjustment of the profile contour of the metal strip by presetting a target value at a plurality of reference positions.

[0071] The invention will be next described in detail with reference to the figures mentioned in the embodiments.

[0072] FIG. 1 shows a cross-section, which is to say the profile contour of a metal strip entered into a system of coordinates, wherein the strip width positions m or bi are plotted on the horizontal axis and on the vertical axis is plotted a profile value for the profile contour. The system of coordinates is thus applied to an arched profile contour which has a curved contour in the center of the width. Positive values for the strip width position extend in FIG. 1 to the right and negative values for the strip width position extend in FIG. 1 to the left, each time in the direction of the width of the metal strip. Individual profile values, which are in each case assigned to concrete positions in the width direction of the metal strip, designate the deviation of the profile contour from the rectangular form of the profile contour, as they are represented by the horizontal axis m/bi. The profile values are therefore offset from the horizontal value perpendicularly downwards and indicated with a positive sign. In other words: the profile values describe in particular the curving of the metal strip at a determined strip position relative to the center of the metal strip. The profile value CL is specified in FIG. 1 with CL=0 because this profile value forms the origin of the coordinate system.

[0073] In FIG. 1 can be at first recognized two profile contours, in particular one illustrating a measured profile, represented in FIG. 1 by a dashed line. In addition, the solid line shows for example a forecast profile contour by means of which a process module was calculated. As shown in FIG. 1, the forecast profile contour has not been adapted yet according to the invention as will be described in the following.

[0074] The core idea of the present invention is that an adaptation of the forecast profile contour or an adaptation of the profile contour curve, also referred to as C.sub.P(n)bi, of the nth metal strip, is in each case applied to a plurality of strip width position bi with i=1, 2, 3, etc., which in FIG. 1 means to the positions bi=b1 through b4. The forecast profile contour corresponds to an aggregation of the calculated profile contour values, or to the profile contour values or forecast values that are mutually interconnected with an interpolation function. Essential for the adaptation according to the invention is the determination of a corresponding adaptation value C(n)bi, which describes the profile deviation, i.e. the difference between the actual value C.sub.actual(n)bi and the associated forecast value C.sub.P(n)bi at the plurality of strip width positions b1 through b4.

[0075] In principle, the strip width positions bi are any positions in the width direction of the metal strip; wherein the width positions are normally defined by their positive or negative distance from the center of the strip. However, in some standardized cases, these band width positions can be advantageously also defined by their distance from the respective natural edge of the metal strip at the drive side and/or at the operating side of the metal strip, because in this case they are measured in the direction of the center of the strip. The band width positions that are defined in this manner are typically referred to as reference positions. These standardized reference positions are then typically also assigned concrete profile values, which are then typically referred to for example as C40 or C100.

[0076] The numerical indication provided after C then corresponds to the distance of the strip width position from the respective natural edge of the metal strip.

[0077] FIG. 1 shows the profile contour over the entire width of the metal strip from the drive side to the operating side. In the subsequent FIGS. 2 and 5 is shown, for simplification purposes, only the right half of the profile contour of the metal strip. The adaptation values or differences determined in this half can be accepted as adaptation value or differences between the forecast and the measured profile contour, at least by means of a mirror-like approximation, also for the left half of the profile contour.

[0078] As an alternative, the values measured and calculated for the profile contour are also formed by forming average values of the contour values in the mirror-like positions i=1, i=1, i=2, i=2, i=3, i=3, and/or i=4, i=4 on the drive or operating side. Negative index values only make it clear that this is the opposite side. It is preferred in this case when the entire measured strip contour is applied in order to suppress potential signal noise or strip contour signals. The calculation of the profile contour and the corresponding adaptation according to the invention can be carried out so that they are symmetrical only for a half of the strip, or asymmetrical for the entire width.

[0079] FIG. 2 illustrates the method according to the invention for producing a metal strip or in particular for adaptation of the profile contour of a metal strip.

[0080] FIGS. 2.1-2.3 illustrate the circumstances based on a simplified example. Only a short-term adaptation was applied. The purpose of the figures is to illustrate the effect of the contour adaptation on a plurality of the reference points bi, in this case 2 reference points.

[0081] FIG. 2.1 in this case first illustrates the determination according to the invention of the adaptation value at an nth metal strip, which is illustrated in a simplified manner only for the right strip half on an example with only two adaptation points. Reference can be made to the previous description of FIG. 1 with respect to the description of the FIG. 2.1; this is also applicable in the same measure to the FIG. 2.1. It should only be mentioned once again that the strip width positions or points in the direction of the width, which is where the calculation of the profile values is carried out, are generally numbered with the parameter m, in particular when the calculation is performed from the strip center CL. Similarly, the reference positions bi are strip width positions, which, however, are not defined from the center of the strip but based on their distance from the natural edge of the metal strip.

[0082] The parameter m is used not only in FIG. 2.1, but also in the subsequent figures as a reference to the entire contour or the entire number of contour calculation points. In contrast to the parameter bi, it should be regularly understood as a reference to discrete values (reference positions).

[0083] The distances of these reference positions bi from the edge of the strip are the same in FIG. 2.1 and FIG. 2.2, as well as in FIG. 2.3 for the difference strip width n and n+1.

[0084] FIG. 2.1 illustrates the determination of individual adaptation values C(n)b1 and C(n)b2 as a difference between individual forecast values C.sub.P(nbi) with i=1 and i=2 and the actual values C.sub.actual(n)bi for the profile contour of the nth metal strip.

[0085] FIG. 2.2 illustrates the determination according to the invention of an adaptation contour. The adaptation contour is determined for the next strip n+x. The width of the strip n can be for example different than the width of the strip n+x. Only the adaptation values bi of the strip n or/and the values with the use of long-term adaptation by means of average value formation for a number of strips j are determined and used for the next strip n+x. The adaptation contour and the point sequence C(n+x)m (with the index m) is always used only in connection with the strip n+x.

[0086] In FIG. 2.2 and FIG. 2.3 are registered the determined adaptation values C(n)b1 and C(n)b2. They are used therein in a simplified example for the next strip n+x (wherein x=1) for the determination of the adaptation contour. Therefore, the adaptation values above can be also described with C(n+x)b1 and C(n+x)b2 (wherein x=1). In addition to both of these adaptation values at the reference positions b1 and b2, a further trivial value, in this case the value in the center of the bank, wherein m=1 in FIG. 2.2, which is in this case the value in the center of the strip, is also taken into account for the determination of the adaptation contour. The value CL in the center of the strip is CL=0 because the coordinate system has been arranged as passing through this point. The adaptation values were determined at the points b1 and b2 for strip n and for strip n+1 (wherein x1).

[0087] As shown in FIG. 2.2, the adaptation contour C(n+1) for the n+1 metal strip is then obtained as the last attachment or interpolation function, one at a time, via the strip center CL=0 and via the two mentioned adaptation values and at the reference points C100 and C25, wherein both last measured items are measured as a distance from the natural edge of the metal strip.

[0088] The formation of an attachment or interpolation function and the interpolation between the center of the strip and the reference point b1, as well as the corresponding formation and interpolation between the reference point b1 and the reference point b2, can be as a rule carried out separately and independently of each other. In order to avoid an irregularity at a transition point of two interpolation functions, for example at the position b1 in FIG. 2.2, the condition for the formulation of both partial interpolation functions is met, namely that it must be possible to continuously differentiate between both of these adjacent partial interpolation functions at the transition point, which is to say that the respective functions must have the same gradients in this position.

[0089] This procedure is as a rule carried out for all adaptation regions in the width direction of the metal strip. In this (symmetrical) example, the adaptation contour starts at the strip center CL with a horizontal tangent.

[0090] The adaptation contour can be determined by extrapolation from the last adaptation value, in FIG. 2.2 at the reference position i=2, until the end point m.sub.max of the metal strip where no profile value is specified. The interpolation or extrapolation is used in order to interpolate or extrapolate based on the predetermined profile value at the reference positions the profile values at other strip width positions m.

[0091] FIG. 2.3 illustrates that similarly to the illustration according to the previous FIG. 2.2, the adaptation contour determined for the n+1th metal strip can be now taken into account for the forecast and subsequent production of the n+nth metal strip to be processed by rolling.

[0092] FIG. 2.3 shows inter alia the calculated adapted profile contour C.sub.P(n+1)m as well as the calculated adapted forecast value C.sub.P(n+1)b1 and C.sub.P(n+1)b2 and a corresponding forecast profile contour C.sub.P(n+1)m.sub.OA, also shown with dashed lines, with o.a: without adaptation, here as an example for the n+1the metal strip, which is to say that it is shown here as an example for the next metal strip to be processed by rolling.

[0093] The adaptation values C(n)b1 and C(n)b2 previously determined according to FIG. 2.1 for the nth metal strip can be added to the forecast value at the corresponding reference positions in order to obtain improved adaptive forecast values for the forecast adapted profile values or profile contours.

[0094] Alternatively or additionally, the adaptation contour C(n+1) determined according to FIG. 2.2 for the n+1th metal strip previously can be added to the forecast profile contour C.sub.P(n+1)m.sub.OA determined for the n+1 metal strip in order to obtain a correspondingly improved or adapted profile C.sub.P(n+1)m, see also claim 9.

[0095] The new adapted forecast values obtained in this manner or the new profile contours can be advantageously used in order to set the profile activators during the production of the n+1th metal strip, generally of the n+xth metal strip, with an even higher precision with respect to the desired target value or/end target contours.

[0096] In mathematical terms, the adapted strip contour values or the adapted strip contour, for example for the n=1th metal strip to be rolled, can be calculated according to the following formula:

C.sub.P(n+1)m.sub.OA+C(n+1)m=C.sub.P(n+1)m

[0097] wherein [0098] C.sub.P(n+1)m is the corrected or adapted profile contour of the n+1th metal strip over the strip width; [0099] C.sub.P(n+1)m.sub.OA is a calculated or forecast profile contour of the n+1th metal strip over the strip width m without adaptation; [0100] C(n+1)m adaptation contour: the values of the adaptation contour at the position m for the metal strip n+1; [0101] m=1 . . . m.sub.MAX.

[0102] The width position m can also correspond to the reference positions bi.

[0103] The difference or adaptation C(n)m between the measured and the calculated correction is shown in the example indicated in FIG. 2.2 in order to simplify the description/representation only for one metal strip. As a rule, this difference is determined for the metal strip rolled as the last one and/or the last but one and/or for a plurality of metal strips of the same type, or possibly also formed in this manner with a different weighting.

[0104] FIG. 3 shows an application field for the use of the contour adaptation according to the invention, or for avoiding undesired beads in the edge region of a metal strip. In this embodiment shown in FIG. 3, the reduction of the bead is carried out with a targeted increase of a value of the profile contour in a reference position, in FIG. 3 it is the position C40, which is to say 40 mm from the natural edge of the metal strip.

[0105] Without using the contour adaptation, strips expected to have normal profile contours are calculated or forecast; see the dotted outline contour according to the first calculation step without contour adaptation in FIG. 3. After carrying out the method according to the invention described previously, in particular with reference to FIG. 2.3, for contour adaptation with the addition of a profile contour forecast for the strip n+x and with an adaptation contour determined for a previous strip, the target adapted contour C.sub.P(n+x)m according to the invention shown in FIG. 3 can be determined for the n+xthe metal strip. The advantage of the C.sub.P(n+x)m adapted according to the invention over the non-adapted forecast profile contour (CP(n+x)m.sub.OA can be clearly seen in FIG. 3, because the undesirable bead with the bead height W1 is only recognizable in the adapted profile contour for the first time in the edge region of the metal strip; in the non-adapted forecast profile (dashed line), the bead is not recognizable so clearly. To this extent, the profile adaptation according to the invention provides an improved calculation result for determining a precise profile contour and opens up new possibilities for improving the profile contour, in this case in particular for reducing the height of the bead. If for example an edge bead height W1 is calculated for the metal strip according to FIG. 3, which is greater than a threshold value for an allowable bead height, a process model is calculated within the context of the predetermined allowable limits, for example C40-target.sub.min and C40-target.sub.max of the profile value at the corresponding strip edge position, in this case at 40 mm from the natural edge of the metal strip, and it is set automatically to a new value, which is increased in this case, so that the allowable height of the bead will not be exceeded or reduced. As a result of said increase of the predetermined profile, the amount of the example of the bead height shown in FIG. 3 is reduced by the amount P from W1 to W2.

[0106] Alternatively or additionally, for the same conditions and the same profile contours as shown according to FIG. 3, with the use of adapted profile contours for controlling the bead height, an increased force level is achieved within the context of the process and facility limits in the rear frames of a finishing line, or with a reversing frame in which subsequent rear passes are used. The can be achieved with a distribution of the rolling force, i.e. by relieving the front frames or the earlier passes and with a stronger load on the rear frames or subsequent passes and/or by moving up one frame or a plurality of frames (the latter frame or the letter passes of the frame in the rolling line or the central pass). FIG. 4.1 shows examples of an advantageous rolling force distribution that is used in order to reduce the bead height W1 (see FIG. 4.2). With an iteratively determined higher load in the rear frames, the flattening output of the processing rollers is increased, see the dashed line in FIG. 4.2 (2. calculation step). The mechanical profile actuators are in the iterative calculation process adjusted to these new edge conditions and set for example for a C40 target profile.

[0107] The knowledge of the profile contour that can be expected as a result of physical modeling of the relevant conditions and of the adapted profile contour at a plurality of positions bi is further actively used over the width of the metal strip in order to adjust a nominal strip profile at the edge of the strip, for example at the position C25, additionally also to the strip profile in the central region of the stripexpressed by C body or C100and maintained within allowable minimum and maximum limits C100.sub.min, C100.sub.max, as shown in the example of FIG. 5. With progressive profile presetting, additional process limits are advantageously introduced and the minimum and maximum profile limits are taken into consideration for a plurality of strip contour points, such as for example C25 and C100. The improved result (2. calculation result) is represented by the strip contour with the solid line.