Rolling method, computer program product, and rolling system

Abstract

The invention relates to a method (100) for rolling flat rolling stock (1; 1a), to a computer program product, and to a rolling system (2) for rolling flat rolling stock (1; 1a). In the process, a target contour (Z) of the flat rolling stock (1; 1b) after a rolling process in the rolling system (2) is specified (S1) and the actual contour (I) of the flat rolling stock (1; 1a) prior to the rolling process in the rolling system (2) is provided (S2). Additionally, at least two control values (S) are ascertained (S3) for a rolling system (2) control mechanism (7a, 7b), by means of which the contour (10) of the rolling stock (1; 1a) can be influenced during the rolling process. The at least two control values (S) are advantageously ascertained on the basis of the target contour (Z) and the actual contour (I) using a process model that represents the rolling process in the rolling system (2). The rolling system (2) is then operated (S4) using the at least two control values (S), wherein the control mechanism (7a, 7b) is non-symmetrically actuated using the at least two control values (S).

Description

[0001] Description

[0002] Rolling process, computer program product and rolling mill

[0003] field of technology

[0004] The present invention relates to a method for rolling flat rolled stock, a computer program product and a rolling mill for rolling flat rolled stock.

[0005] State of the art

[0006] A key factor in assessing the quality of a rolled product is its contour, i.e., its shape as viewed in cross-section. The contour is significantly influenced by the rolling process. If contours are unfavorable for further processing, this usually results in economic loss and / or considerable labor expenditure, as the rolled stock may require reworking, cannot be used for a planned application, or must be disposed of as scrap.

[0007] Rolling mills typically have several control mechanisms available to influence the contour. Typical control mechanisms include bending, pair cross, and swiveling of work rolls, which can be achieved by controlling appropriate actuators. Alternatively or additionally, the contour can also be influenced by controllable roll or rolling stock cooling or an edge heater.

[0008] A generally desired contour is characterized by axial symmetry with respect to the center of the rolled stock. However, various effects during the rolling process can undesirably create asymmetrical contours. For example, the rolled stock may already have an asymmetrical contour before entering one or more rolling stands, which cannot be corrected during a conventional rolling process. Likewise, an asymmetrical temperature distribution of the rolled stock to be rolled can cause asymmetry in the contour. Asymmetrical tension distributions in the rolled stock, which can arise, for example, during solidification after a casting process, are also problematic. Wear or inaccurate positioning of the work rolls, among other things, can also have a detrimental effect on the symmetry.

[0009] DE 10 2009 043 401 A1 discloses a model-based strip travel control system for a hot strip wide mill. In a first sub-process, the setpoint values ​​of asymmetrical roll stand adjustment mechanisms, such as pivoting and asymmetrical bending forces, and in a second sub-process, the setpoint values ​​of symmetrical roll stand adjustment mechanisms, such as symmetrical bending forces, means for axially shifting so-called CVC work rolls, and / or so-called "pair crossing," are calculated simultaneously. A target speed distribution is specified for each roll stand, from which strip thickness contours upstream and downstream of the respective stand are derived. A rolling force distribution is then determined for each stand, which is used to calculate the flattening of the rolls in the respective stand. The calculated flattening values ​​can then be used with the previously obtained strip thickness contours downstream of the stand to calculate symmetrical and asymmetrical target contours.The target values ​​can then be calculated from the target contours.

[0010] Summary of the invention

[0011] Against this background, it is an object of the present invention to improve the control over the contour in a rolling process, in particular to specifically influence the asymmetrical part of the contour.

[0012] This object is achieved by a method for rolling flat rolled stock, a computer program product and a rolling mill for rolling flat rolled stock according to the independent claims.

[0013] Preferred embodiments of the invention are the subject of the independent claims and the following description.

[0014] According to a first aspect of the invention, in a method for rolling flat rolled stock, in particular a metal strip, a target contour of a flat rolled stock is specified after a rolling process in a rolling mill and an actual contour of the flat rolled stock is provided before the rolling process in the rolling mill, wherein the target contour characterizes a desired cross-sectional shape of the rolled stock after the rolling process and the actual contour characterizes the actual cross-sectional shape of the rolled stock before the rolling process. In addition, at least two control values ​​for an actuating mechanism of the rolling mill, with which the contour of the rolled stock can be influenced during the rolling process and which has at least two independently controllable actuating elements, are determined, in particular online. The at least two control values ​​are expediently determined using a process model that maps the rolling process in the rolling mill, on the basis of the target contour and the actual contour.The rolling mill is then operated with the at least two control values, wherein the at least two actuators of the actuating mechanism are controlled non-symmetrically independently of one another with the at least two control values ​​in such a way that the actual contour is converted into the target contour.

[0015] One aspect of the invention is based on the approach of specifically influencing a non-symmetrical portion of a contour of a rolled stock, for example a metal strip, after a rolling process in a rolling mill by appropriately controlling the rolling mill. For example, a non-symmetrical contour of the rolled stock can be proactively counteracted by appropriately controlling the rolling mill. However, it is also conceivable with this approach to specifically create a non-symmetrical portion of the contour in the rolled product. In both cases, it is provided to determine control values ​​for an actuating mechanism that influences a contour of the rolled stock during the rolling process for a non-symmetrical control of at least two actuators of the actuating mechanism.The non-symmetrical control allows the targeted formation of a non-symmetrical portion of the contour of the finished rolled product - or to counteract the formation of a non-symmetrical portion caused by other effects during the rolling process.

[0016] For this purpose, information about the rolling stock to be rolled and preferably also about the rolling mill, for example about its components and / or its condition, is expediently first gathered. Generally speaking, this means that at least a large part of the conditions under which the rolling process will take place can be determined. For example, in addition to the actual contour of the rolling stock to be rolled, which has not yet been explicitly taken into account in conventional methods - in DE 102009 043401 A1 this is derived from the specified target speed distribution - further information about its geometry, such as its thickness and / or width, can also be provided. For even more precise control over the asymmetrical contour portion, the material properties, the chemical composition, the temperature and / or even a temperature distribution in the rolling stock to be rolled can also be provided.Alternatively or additionally, a description of the system, for example, the number of work rolls, their geometry, mechanical system limits, and / or the like, can be provided. Likewise, alternatively or additionally, the system status can be described by providing the current positions of the actuators that implement a control mechanism influencing the rolling stock contour, the current wear of the work rolls, and / or the like. Furthermore, process specifications can be taken into account, for example, the actuator control ranges, thickness reduction distributions for several consecutive rolling passes, and / or the like.

[0017] In contrast to DE 102009 043401 A1, where a roll gap target contour results from a flattening resulting from a specific rolling force distribution, a desired contour ("target contour") of the rolled stock after the rolling process is expediently specified explicitly, for example in the form of a function or a data curve. It is also conceivable to specify discrete contour parameters that describe the target contour sufficiently well. Alternatively or additionally, an acceptance range can be specified, i.e. a contour corridor within which the target contour should be located. As already indicated, when specifying the target contour, not only a conventional profile value or a symmetrical rolled stock contour can be specified, but also a non-symmetrical contour or at least a parameter derived therefrom.If necessary, the target contour can also be specified by specifying a symmetrical contour portion, such as a conventional profile value, and simultaneously specifying a separate, non-symmetrical contour portion.

[0018] The information about the rolling stock to be rolled, in particular the actual contour - and if necessary also about the plant or rolling conditions - and the target contour can then be used as a basis for modeling the rolling process. For example, the actual contour and the target contour can be used as variables in a model, preferably alongside the other information provided. The model is preferably based on physical-mathematical equations. Alternatively or additionally, the model can also be machine-learned, i.e. be based on artificial intelligence. Control values ​​can be obtained as output variables from this process model, which can be used to operate the rolling mill. The control values ​​are expediently assigned in particular to those control mechanisms which can produce a non-symmetrical contour or non-symmetrical contour components through non-symmetrical control of their actuators.This non-symmetrical control of the actuators, in particular with at least two control values ​​each, makes it possible to compensate for effects that were not controllable or could only be controlled with great effort and which previously led to non-symmetrical contours of rolled products and / or to convert them into a desired non-symmetrical contour.

[0019] Preferred embodiments of the invention and their further developments are described below. These embodiments can be combined with each other and with the aspects of the invention described below, unless expressly excluded.

[0020] Mechanical and / or thermal adjustment mechanisms are particularly suitable as adjustment mechanisms that can be controlled non-symmetrically. With a thermal adjustment mechanism, for example, non-symmetric temperature distributions can be specifically created in the rolling stock or in the work rolls, as will be explained in more detail below. With a mechanical adjustment mechanism, on the other hand, at least two rolls can be moved or positioned non-symmetrically to one another. Alternatively or additionally, with a mechanical adjustment mechanism, at least one roll can be deformed non-symmetrically. With mechanical adjustment mechanisms, therefore, it is expedient to involve at least two actuators ("control elements"), each of which is controlled by a control value.In contrast to a conventional control of such actuating mechanisms, in which the actuators are usually controlled with the same control value, a non-symmetrical control can be implemented by moving the two actuators by different distances or in different directions.

[0021] In a preferred embodiment, the contour of a roll gap between two work rolls of the rolling mill is therefore set asymmetrically, in particular in a targeted manner, by controlling the at least two actuators of the adjusting mechanism with the at least two control values. A asymmetrically set contour of the roll gap is preferably a contour that is not symmetrical with respect to a rolling plane defined between two cylindrical work rolls aligned parallel to one another and a roll gap center point. Since work rolls, for example, are used to apply a desired rolling pressure ora desired setting force, for setting a desired profile and / or the like are usually mounted hydraulically movable anyway, the asymmetrical adjustment of the roll gap contour represents a particularly low-cost and easy-to-implement measure for controlling the asymmetrical contour component in the finished rolled product. In particular, this measure can also be easily implemented in existing rolling mills without the need for complex conversions or retrofitting.

[0022] The asymmetrical roll gap contour can be adjusted, for example, by an asymmetrical movement of an upper roll of the rolling mill and a lower roll of the rolling mill relative to each other. The adjusting mechanism can therefore be controlled in such a way that the upper roll and the lower roll are moved asymmetrically relative to each other. A asymmetrical movement of the two rolls relative to each other is expediently a movement that is not symmetrical with respect to the rolling plane of the rolling mill and / or the center point of the roll gap. The center point of the roll gap is preferably the center point of the cross-section of a rolled stock located between the upper and lower rolls. The roll can be a work roll or an intermediate roll.The non-symmetrical movement of the two rolls relative to each other allows the non-symmetrical adjustment of the roll gap contour without exposing the rolls to excessive stress due to pressure peaks and the associated increased wear.

[0023] A non-symmetrical movement of the upper and lower rolls relative to each other can, for example, be a non-symmetrical "pushing" of the two rolls. "Pushing" is preferably understood to mean an axial, counter-rotating movement of the two rolls. During non-symmetrical pushing, the two rolls are moved axially by different distances - for example, by appropriately controlling at least one actuator assigned to the upper and at least one to the lower roll. This results in a movement of the rolls that is not symmetrical with respect to the roll gap center point. A non-symmetrical roll gap contour can then result from a non-symmetrical grind of the rolls with respect to the roll center. Alternatively, a non-symmetrical movement can also be a non-symmetrical "pivoting" of the two rolls. "Pivoting" is preferably understood to mean a change in the angle between the rolling plane and the respective roll axis.During asymmetric pivoting, the two rollers are positioned at different angles to the rolling plane—for example, by appropriately controlling at least one of the upper and at least one of the lower rollers. This results in a movement of the rollers that is not symmetrical with respect to the rolling plane.

[0024] Alternatively or additionally, a non-symmetrical roll gap contour can also be achieved by applying different forces to the upper roll and / or the lower roll at both ends. The adjusting mechanism can therefore be controlled in such a way that different forces are applied to the upper roll and / or the lower roll at both ends. This can be achieved by controlling the bending cylinders assigned to the rolls differently. The forces generated in this way on the roll ends expediently have at least one force component transverse to the respective roll axis. This allows the upper and / or lower roll to be bent non-symmetrically. It has been found that this type of non-symmetrical bending can reliably compensate for a variety of effects that cause a non-symmetrical contour component in the finished rolled product.

[0025] In principle, it is also conceivable to create a non-symmetrical roll gap contour by applying a different force to the two ends of the upper roll than to the two ends of the lower roll. This results in a greater bulge on one (top) side of the finished rolled product – with respect to a transverse axis running in the width direction – than on the other (bottom) side.

[0026] As already indicated above, as an alternative or in addition to such mechanical adjusting mechanisms, a non-symmetrical control of actuators of a thermal adjusting mechanism is also conceivable. In particular, when the rolling process is not imminent, i.e. when sufficient time is available for the development of a predetermined temperature distribution in the rolling stock or in a work roll, it can be advantageous to avoid (additional) mechanical stress on the work roll caused by its bending or movement by tempering the rolling stock or the work roll differently on one side of the rolling stock or the work roll with respect to a central area than on the other side. In other words, one half of the rolling stock or the work roll - viewed in the width direction or axially - can be given a different temperature or temperature distribution than the other half.For this purpose, two opposing edge heaters ("actuators"), between which the rolling stock passes, are preferably controlled differently. Alternatively or additionally, a roll cooling system consisting of at least two parts, which can be used, for example, to generate an axial temperature gradient in a work roll, can also be controlled accordingly.

[0027] As already mentioned above, such non-symmetrically controlled actuators can also be used to deliberately create a non-symmetrical contour of the rolled stock after the rolling process. This may be desirable or even necessary for certain applications of the finished rolled product. In such cases, it may be advantageous to specify the target contour as a contour with a symmetrical component and a non-zero non-symmetrical component.

[0028] Particularly when a plurality of rolled products are to be rolled consecutively, it can be advantageous to determine the rolling stock contour, in particular of a rolled stock rolled according to the invention, by sensor after the rolling process and to determine at least two further control values ​​for the control mechanism based on the sensor data generated thereby. In order to be able to adjust the rolling stock contour of the subsequently rolled rolled products even more closely to the target contour, the rolling mill is expediently continued to operate with the at least two further control values, wherein the at least two actuators of the control mechanism are controlled non-symmetrically with the at least two further control values.In contrast to the initial determination of at least two control values, in which the effects of the control mechanism on the contour of the finished rolled product are predicted purely based on a model, this allows influences not included in the rolling process model and / or plant and / or rolling stock parameters that are only vaguely determined or determinable to be taken into account during continued operation of the rolling mill. This approach, i.e., the recourse to the sensor-determined rolling stock contour of a previously rolled product, can also be referred to as online adaptation.

[0029] The at least two additional control values ​​can be determined, for example, by comparing the sensor-determined rolling stock contour with the target contour. Depending on the degree of agreement between these two contours, the at least two initially determined control values ​​can be adjusted. Such optimization of the at least two control values ​​can be achieved using a cost function, which is preferably selected depending on the application. It is particularly useful to include deviations in the asymmetrical portion of the contours in the cost function. An additive, weighted term is conceivable, for example.

[0030] Alternatively or additionally, it is also conceivable to compare at least one rolling stock contour obtained after one of several rolling processes in which similar rolling stock was rolled with the target contour and to adapt the process model on the basis of the comparison. The adaptation is expediently carried out under the proviso that this increases the agreement between a rolling stock contour predicted by the process model and assigned to the at least two control values ​​and the target contour. This is particularly possible because after the several rolling processes the condition of the rolling mill, in particular the control values ​​of various control mechanisms, and the resulting rolling stock contour after rolling are precisely known. This also makes it possible to improve the agreement between the achievable rolling stock contours and the target contour for subsequent rolling stock. This procedure, i.e. the subsequent adaptation of the process model, can also be referred to as recalculation.

[0031] Typically, the target contour for the rolled stock is specified after a final pass, i.e., for the rolled stock after passing through the last rolling stand of the rolling mill. To be able to control the shape of the rolled stock contour even more precisely, and in particular to be able to operate individual rolling stands to optimize the rolled stock contour, it is advisable to specify the target contour for the rolled stock already between two rolling stands of the rolling mill. In particular, this allows for the specification of several target contours, which the rolled stock should assume after passing through the preceding rolling stand.

[0032] A second aspect of the invention relates to a computer program product for implementing the method according to the first aspect of the invention. Such a computer program product can, for example, be executed on a control system of a rolling mill in order to carry out the method by means of the rolling mill. The computer program product expediently contains instructions which, when executed by a computer, such as the control system of the rolling mill, cause the computer to execute the method according to the first aspect of the invention.

[0033] A third aspect of the invention relates to a rolling mill for rolling flat rolled stock, in particular metal strip, having an actuating mechanism with which the contour of flat rolled stock can be influenced during a rolling process in the rolling mill and which has at least two independently controllable actuators. The rolling mill also has a control value determiner which is configured to determine at least two control values ​​for the actuating mechanism using a process model that maps a rolling process in the rolling mill, based on a predetermined target contour of the flat rolled stock after the rolling process and an actual contour of the flat rolled stock before the rolling process. In addition, a control device is provided which is configured to operate the rolling mill with the at least two control values ​​when the actuating mechanism is actuated asymmetrically.

[0034] The manipulated variable determiner and / or the control device can be implemented using hardware and / or software. The manipulated variable determiner and / or the control device can, in particular, comprise a processing unit, preferably connected to a memory and / or bus system for data or signals. For example, the manipulated variable determiner and / or the control device can comprise a microprocessor unit (CPU) or a module thereof and / or one or more programs or program modules. The manipulated variable determiner and / or the control device can be configured to process commands implemented as a program stored in a memory system, to acquire input signals from a data bus, and / or to output output signals to a data bus.A storage system can comprise one or more, in particular different, storage media, in particular optical, magnetic, solid-state, and / or other non-volatile media. The program can be designed in such a way that it embodies or is capable of executing the method described here or at least parts thereof, so that the control value determiner and the control device can jointly execute the steps of this method and thus, in particular, operate the rolling mill for rolling flat rolled stock.

[0035] 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 an embodiment, which is explained in more detail in conjunction with the drawings. These show, at least partially schematically:

[0036] Fig 1 an example of a rolling stock contour;

[0037] Fig 2 shows an example of a rolling mill for rolling flat rolled stock;

[0038] Fig 3 shows an example of a control mechanism controlled non-symmetrically with at least two control values; and

[0039] Fig 4 an example of a method for rolling flat rolled stock.

[0040] Where appropriate, the same reference numerals are used in the figures for the same or corresponding elements of the invention.

[0041] Description of the embodiments

[0042] FIG. 1 shows an example of a contour 10 of a flat rolled stock 1, for example, a metal strip. Contour 10 here corresponds to the outline of the cross-section Q through the rolled stock 1 in a plane perpendicular to a longitudinal axis of the rolled stock 1, with the longitudinal axis in the example shown being perpendicular to the plane of the figure.

[0043] The contour 10 shown is a symmetrical contour. This means that the contour 10 is axially symmetrical, firstly, with respect to a transverse axis X1, which runs transversely to the longitudinal axis in the width direction of the rolled stock 1 and is usually located in a rolling plane during rolling of the rolled stock 1, and secondly with respect to the center of the rolled stock 1. The center of the rolled stock 1 is expediently defined by a central axis X2 running transversely to the longitudinal axis in the thickness direction of the rolled stock 1. Thus, there is also point symmetry of the contour 10 with respect to a center point M of the rolled stock 1.

[0044] Contour 10 can be understood as the distribution of the thickness of the rolled stock 1 as a function of the width of the rolled stock 1. Contour 10 can therefore be specified directly as a function or data curve. However, it is also conceivable to specify contour 10, at least approximately, using several discrete contour parameters. In this respect, the shape of the rolled stock 1 can be described more precisely by contour 10 than by the technically conventional profile value. This is because the profile value is merely a scalar value that describes the difference in thickness between the center and an edge of the rolled stock at a specified distance, typically 20 mm or 40 mm.

[0045] FIG 2 shows an example of a rolling mill 2 for rolling flat rolled stock 1a. The rolling mill 2 has a control value detector 3, a control device 4, and at least one, in the present example four, rolling stands 5. Each of the rolling stands 5 comprises two oppositely arranged work rolls 6a, 6b, each defining a roll gap D, of which, for reasons of clarity, only one is provided with a reference numeral. Both the upper work rolls 6a and the lower work rolls 6b are expediently adjustable by means of at least one mechanical adjusting mechanism 7a. In addition, the rolling mill 2 in the present example additionally has further, essentially optional components in the form of a rolling stock cooling system 8 and a sensor device 9.

[0046] The control device 4 is preferably configured to control the rolling mill 2, in particular the rolling stands 5. The control device 4 can, for example, adjust the width of the roll gap D between each pair of upper and lower work rolls 6a, 6b by means of at least one of the mechanical adjusting mechanisms 7a, and thus specify a thickness reduction distribution across the rolling stands 5. Likewise, the control device 4 can influence the temperature of the rolling stock 1a entering the first of the rolling stands 5 by means of the rolling stock cooling system 8, and can determine and, if necessary, process information about the rolling stock 1b, also referred to as the finished rolled product or rolled product, which has left the last of the rolling stands 5 by means of the sensor device 9.

[0047] The control value determiner 3 is expediently configured to determine at least two control values ​​S based on a predetermined target contour Z for the finished-rolled product 1b and a provided actual contour I, determined, for example, upstream of the first of the rolling stands 5 by a sensor device (not shown), on the basis of which at least one of the mechanical actuating mechanisms 7a—and / or, as explained below, also at least one thermal actuating mechanism 7b—can be controlled. The control value determiner 3 can be implemented in hardware for this purpose, for example as a microcontroller or integrated circuit. However, the control value determiner 3 is preferably implemented in software, for example as a program or program module. Particularly preferably, the control value determiner 3 is implemented as a program (module) on the hardware of the control device 4.

[0048] The control value determiner 3 preferably determines the at least two control values ​​S in such a way that - after appropriate adjustment of at least one pair of work rolls 6a, 6b by means of the mechanical adjustment mechanisms 7a according to the at least two control values ​​S - the contour 10 of the finished rolled product 1b has the greatest possible correspondence with the target contour Z. For this purpose, the control value determiner 3 expediently uses a process model that maps the rolling process in the rolling mill 2. In addition to the actual contour I and the target contour Z, other input variables that characterize the state of the rolling mill 2, the state of the rolling stock 1a to be rolled and / or process conditions can also be used.

[0049] The control device 4 is accordingly expediently configured to control at least one of the adjusting mechanisms 7a, 7b on the basis of the at least two actuating values ​​S. For example, the control device 4 can move at least two actuators (not shown) acting on one or more of the work rolls 6a, 6b or on backup rolls (not shown) supporting the work rolls 6a, 6b, which form one of the mechanical adjusting mechanisms 7a, in accordance with the at least two actuating values ​​S. As a result, the work rolls 6a, 6b can be repositioned, in particular in pairs, or their shape can be influenced. For example, the work rolls 6a, 6b can be displaced axially (i.e., perpendicular to the plane of the figure) or pivoted (i.e., positioned obliquely to the top and bottom of the incoming rolling stock 1a) in pairs.In this way, it is possible to adapt the contour of the roll gap D defined by the controlled work rolls 6a, 6b in such a way that the contour 10 of the finished rolled product 1b after the rolling process in the rolling mill 2 at least substantially corresponds to the target contour Z.

[0050] In conventional rolling mills, non-symmetrical actual contours I, thermal effects during the rolling process, wear effects on the work rolls and / or the like generally result in the contour of finished rolled products having a non-symmetrical component after the rolling process.

[0051] In order to be able to specifically control this component, for example, to compensate for it or reduce it to a desired degree or to transform it into a desired asymmetry, the control device 4 of the rolling mill 2 shown here is configured to non-symmetrically control at least one of the adjusting mechanisms 7a, 7b with the at least two control values ​​S. The control device 4 can in particular be configured to control at least one of the mechanical adjusting mechanisms 7a with the at least two control values ​​S such that the roll gap D between the upper and lower work rolls 6a, 6b assigned to the adjusting mechanism 7a assumes a non-symmetrical contour.For example, the upper work roll 6a can be adjusted by a first angle to the top side of the incoming rolling stock 1a according to one of the control values ​​S by means of an actuator, and the lower work roll 6b can be adjusted by a second angle, different from the first angle, to the bottom side of the incoming rolling stock 1a according to another of the control values ​​S by means of a different actuator. If the work rolls 6a, 6b are ground in a special way, for example with an asymmetrical grind with respect to the roll center, it can also be expedient to axially displace the upper work roll 6a by a first distance according to one of the control values ​​S by means of an actuator, and the lower work roll 6b by a second distance according to another of the control values ​​S by means of a different actuator in the opposite direction.Alternatively or additionally, at least one of the work rolls 6a, 6b can also be bent non-symmetrically, as described in more detail below in connection with FIG 3.

[0052] Since, as already mentioned, thermal effects can also influence the contour 10, for example, non-symmetrical temperature distributions in the incoming rolling stock 1a, it is alternatively or additionally conceivable to at least partially influence the non-symmetrical portion of the contour 10 by means of the rolling stock cooling system 8. In this sense, the rolling stock cooling system 8 can form a thermal control mechanism 7b, at least if the rolling stock cooling system 8 can generate a non-symmetrical temperature distribution, for example, a temperature gradient, in the incoming rolling stock 1a.In this case, it is preferred that the control device 4 can control not only the mechanical actuating mechanisms 7a, in particular the corresponding actuators for moving or deforming the work rolls 6a, 6b or possibly also backup rolls not shown, but also or alternatively the thermal actuating mechanism 7b with at least two actuating values ​​S determined by the actuating value determiner 3 on the basis of the process model. According to the actuating values ​​S, for example, one half of the rolling stock 1a can be cooled more intensively than the other half, for example by adjusting the temperature or pressure of the coolant sprayed onto the rolling stock 1a by the rolling stock cooling system 8 accordingly.

[0053] Alternatively or in addition to the rolling stock cooling system 8, a thermal adjustment mechanism 7b can also be formed by edge heaters (not shown) or roll cooling systems (not shown).

[0054] If some system parameters are not known with sufficient accuracy, for example, the surface shape of the work rolls 6a, 6b, which is constantly changing due to wear, their temperature, and / or the like, in order to achieve even better rolling results, after rolling at least a first finish-rolled product 1b, its properties can be recorded by means of the sensor device 9 and taken into account during the rolling of subsequent rolled goods 1a. In particular, these recorded properties, in particular the contour 10 and particularly preferably the asymmetrical portion of the contour 10, can be included in the determination of the control values ​​S for the subsequent rolled goods 1a. In this way, the control values ​​S can be effectively optimized, and the conformity of the contour 10 of the finish-rolled products with the target contour Z can be further improved.

[0055] FIG. 3 shows an example of an actuating mechanism 7a that is non-symmetrically controlled by at least two actuating values ​​S, determined in particular on the basis of a predetermined target contour and a provided actual contour using a process model. In this example, the actuating mechanism 7a is formed by two actuators 11 designed as bending cylinders. A work roll 6 can be bent via the actuating mechanism 7a. For this purpose, the actuators 11 exert a force F on the work roll 6 at each of the two ends 12 of the work roll 6, essentially perpendicular to the roll axis W.

[0056] With the non-symmetrical control of the adjusting mechanism 7a, the forces F are not exerted in the same direction as usual, but, as shown in FIG 3, essentially in opposite directions on the ends 12 of the work roll 6. For this purpose, one of the two bending cylinders expediently works in one direction according to one of the two control values ​​S, while the other of the two bending cylinders works in the opposite direction according to the other of the two control values ​​S. This results in a non-symmetrical bending of the work roll 6 with respect to a rolling plane E, in which the rolled stock rolled by the work roll 6 runs and in which a transverse axis (see FIG 1 , reference symbol X1) of the rolled stock lies.

[0057] FIG 4 shows an example of a method 100 for rolling flat rolled stock.

[0058] In a method step S1, a target contour of a flat rolled stock is specified after a rolling process in a rolling mill, i.e., after passing through a final rolling stand of the rolling mill. In a method step S2, an actual contour of the flat rolled stock is provided before the rolling process in the rolling mill, i.e., before entering a first rolling stand of the rolling mill.

[0059] In a further method step S3, at least two control values ​​for an actuating mechanism of the rolling mill, with which the contour of the rolling stock can be influenced during the rolling process, are determined on the basis of the specified target contour and the provided actual contour. For this purpose, a process model that maps the rolling process in the rolling mill is expediently evaluated with the target contour and the actual contour. In particular, the at least two control values ​​are determined with which the actuating mechanism can be controlled asymmetrically such that the contour of the finished rolled product at least substantially corresponds to the target contour. Preferably, further plant and / or rolling stock parameters are taken into account in the process model, for example the rolling stock temperature, the rolling stock geometry (ieits width and thickness), physical properties of the rolling stock material, the grinding of the work rolls, the degree of wear of the work rolls, the work roll caliber and material, and / or the like. These additional parameters can also be provided or determined in process steps S1 and S2, respectively.

[0060] In a further process step S4, the rolling mill is operated with the at least two control values, with the control mechanism being controlled asymmetrically with the at least two control values. This allows a asymmetric portion of the contour of the rolled stock after the rolling process, i.e., the finished rolled product, to be precisely controlled. In particular, the asymmetric contour portion can thus be reliably reduced to zero.

[0061] Optionally, it can be provided that in a method step S5 the contour of the rolled stock is recorded by sensors after the rolling process and compared with the target contour. On the basis of this comparison, in method step S3 during the subsequent rolling of similar rolled products, further control values ​​for the control mechanism can be determined, thus achieving optimization of the control values. This can further improve the conformity of the contour of the subsequently finish-rolled products with the target contour. Alternatively or additionally, if the resulting rolled stock contours are continuously compared with the target contour during the successive rolling of similar rolled products, at least a good conformity can be maintained, since changes in system parameters affecting the rolled stock contour, for example further wear on the work rolls, can thus be consistently taken into account when determining the control values.

[0062] Although the invention has been illustrated and described in detail by the preferred embodiments, the invention is not limited by the disclosed examples and other variations may be derived therefrom by those skilled in the art without departing from the scope of the invention.

[0063] List of reference symbols

[0064] 1 , 1a, 1b Rolled stock

[0065] 2 rolling mills

[0066] 3 control value determiners

[0067] 4 Control device

[0068] 5 rolling stand

[0069] 6 work roll

[0070] 6a upper working roll

[0071] 6b lower work roll

[0072] 7a, 7b Adjusting mechanism

[0073] 8 Rolled stock cooling

[0074] 9 Sensor device

[0075] 10 Contour

[0076] 11 Actuator

[0077] 12 End

[0078] 100 procedures

[0079] S1 Target contour specification

[0080] S2 Provision of actual contour

[0081] S3 Determination of control values

[0082] S4 Operation of the system

[0083] S5 Recording of the rolling stock contour

[0084] M center

[0085] X1 transverse axis

[0086] X2 central axis

[0087] Q cross-section

[0088] E rolling plane

[0089] W roller axis z target contour

[0090] I Actual contour

[0091] F Force

[0092] S Control value

[0093] D Roll gap

Claims

Claims 1. Method (100) for rolling flat rolled stock (1; 1a), comprising - specifying (S1) a target contour (Z) of a flat rolled stock (1; 1b) after a rolling process in a rolling mill (2), wherein the target contour (Z) characterizes a desired cross-sectional shape of the rolled stock (1; 1b) after the rolling process, - Providing (S2) an actual contour (I) of the flat rolling stock (1; 1a) before the rolling process in the rolling mill (2), wherein the actual contour (I) characterizes the actual cross-sectional shape of the rolling stock (1; 1a) before the rolling process, - Determining (S3) at least two control values ​​(S) for an actuating mechanism (7a, 7b) of the rolling mill (2), with which the contour (10) of the rolling stock (1; 1a) can be influenced during the rolling process and which has at least two independently controllable actuators (11), wherein the at least two control values ​​(S) are determined by means of a process model which depicts the rolling process in the rolling mill (2) on the basis of the target contour (Z) and the actual contour (I), - Operating (S4) the rolling mill (2) with the at least two control values ​​(S), wherein the at least two actuators (11) of the actuating mechanism (7a, 7b) are controlled non-symmetrically independently of one another with the at least two control values ​​(S) in such a way that the actual contour (I) is converted into the target contour (Z).

2. Method (100) according to claim 1, wherein the contour of a roll gap (D) between two work rolls (6; 6a, 6b) of the rolling mill (2) is adjusted asymmetrically by controlling the at least two actuators (11) of the adjusting mechanism (7a) with the at least two adjusting values ​​(S).

3. Method (100) according to claim 1 or 2, wherein an upper roll (6a) of the rolling mill (2) and a lower roll (6b) of the rolling mill (2) are moved non-symmetrically to one another with respect to a rolling plane (E) of the rolling mill (2) or the center point (M) of the roll gap (D).

4. Method (100) according to one of the preceding claims, wherein the upper roller (6a) and / or the lower roller (6b) are subjected to different forces (F) at both ends (12).

5. Method (100) according to one of the preceding claims, wherein the rolling stock (1; 1a) or a work roll (6; 6a, 6b) of the rolling mill (2) is tempered differently on one side of the rolling stock (1; 1a) or the work roll (6; 6a, 6b) with respect to a central region than on the other side.

6. Method (100) according to one of the preceding claims, wherein the target contour (Z) is specified as a contour (10) with a symmetrical portion and a non-vanishing non-symmetrical portion.

7. Method (100) according to one of the preceding claims, wherein - the rolling stock contour (10) is determined by sensors after the rolling process (S5), - on the basis of the sensor data generated thereby, at least two further control values ​​(S) for the control mechanism (7a, 7b) are determined, - the rolling mill (2) continues to be operated with the at least two further control values ​​(S), wherein the at least two actuators (11) of the actuating mechanism (7a, 7b) are controlled non-symmetrically with the at least two further control values ​​(S).

8. Method (100) according to one of the preceding claims, wherein - at least one rolling stock contour (10) obtained after one of several rolling processes in which similar rolling stock (1; 1b) was rolled is compared with the target contour (Z) and - the process model is adjusted based on the comparison.

9. Method (100) according to one of the preceding claims, wherein the target contour (Z) for the rolling stock (1; 1a) is specified between two rolling stands (5) of the rolling mill (2).

10. Computer program product for carrying out the method (100) according to one of the preceding claims.

11. Rolling mill (2) for rolling flat rolled stock (1; 1a), with - an adjusting mechanism (7a, 7b) with which the contour (10) of flat rolling stock (1; 1a) can be influenced during a rolling process in the rolling mill (2) and which has at least two independently controllable actuators (11), - a control value determiner (3) which is configured to determine at least two control values ​​(S) for the control mechanism (7a, 7b) by means of a process model which depicts a rolling process in the rolling mill (2) on the basis of a predetermined target contour (Z) of the flat rolling stock (1; 1b) after the rolling process and an actual contour (I) of the flat rolling stock (1; 1a) before the rolling process, wherein the target contour (Z) characterizes a desired cross-sectional shape of the rolling stock (1; 1b) after the rolling process and the actual contour (I) characterizes the actual cross-sectional shape of the rolling stock (1; 1a) before the rolling process, and - a control device (4) which is designed to operate the rolling mill (2) by independent, non-symmetrical control of the at least two actuators (11) of the actuating mechanism (7a, 7b) with the at least two actuating values ​​(S) in such a way that the actual contour (I) is converted into the target contour (Z).

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