Frequency correlation distribution of adjustment parameters used to change the cross-section of rolled pieces in a rolling mill train

Abstract

Metal workpieces are rolled in mill stands of a rolling mill train. Based on a characteristic parameter representing the change in cross-sectional area of ​​the workpiece exiting a given mill stand, temporary adjustment parameters are first determined for that mill stand and the upstream mill stand, and then used to determine a final adjustment parameter that affects the cross-section of the workpiece exiting the mill stand. The mill stands are then manipulated accordingly. Temporary adjustment parameters for the upstream mill stand are determined by frequency filtering of the characteristic parameter or intermediate parameters derived therefrom. The frequency filter is designed such that, when the temporary adjustment parameters are determined, only the frequency components of the characteristic parameter below the limiting frequency are included. The limiting frequencies are the same or increase from one mill stand to the next. The temporary adjustment parameters for a given mill stand are thus determined such that, when determined, at least the frequency components of the characteristic parameter above the limiting frequency of the mill stand directly upstream are included.

Description

Technical Field

[0001] This invention starts with a method for operating a rolling mill train for rolling works made of metal.

[0002] - The rolling mill train has multiple rolling mill stands, through which the workpiece passes in succession along a uniform conveying direction for the rolling mill stands, thereby allowing the workpiece to be rolled consecutively within the rolling mill stands.

[0003] - Wherein, based on a characteristic parameter representing the cross-sectional change of the rolled piece flowing from a specific mill stand of the mill train, the control device of the mill train, for the mill stand and a certain number of mill stands arranged upstream of the mill stand in the conveying direction of the mill train, first determines the corresponding temporary adjustment parameters, and then, using the corresponding temporary adjustment parameters, obtains the corresponding final adjustment parameters.

[0004] -The corresponding final adjustment parameters affect the cross-section of the rolled piece flowing out from the corresponding mill stand in the mill train.

[0005] -The control device operates the mill stand according to the corresponding final adjustment parameters.

[0006] Furthermore, the present invention starts from a control program, wherein the control program includes program code that can be executed by a control device for a mill train having multiple mill stands, wherein the execution of the program code causes the control device to control the mill train according to such an operating method.

[0007] Furthermore, the present invention relates to a control device for a rolling mill train used for rolling workpieces made of metal, wherein the rolling mill train has multiple rolling mill stands, and the workpiece passes sequentially through these rolling mill stands along a uniform conveying direction for the rolling mill stands, thereby causing the workpiece to be rolled sequentially within the rolling mill stands.

[0008] The control device has a known path. Using this known path, and based on a characteristic parameter representing the cross-sectional change of the rolled piece flowing from a specific mill stand in the mill train, the control device first determines corresponding temporary adjustment parameters for the mill stand and a certain number of mill stands arranged upstream of the mill stand in the conveying direction of the mill train. Then, using these temporary adjustment parameters, it obtains the corresponding final adjustment parameters.

[0009] -The corresponding final adjustment parameters affect the cross-section of the rolled piece flowing out from the corresponding mill stand in the mill train.

[0010] -The control device operates the mill stand according to the corresponding final adjustment parameters.

[0011] Furthermore, the present invention originates from a rolling mill for flat rolled products.

[0012] - The rolling mill train has multiple rolling mill stands, and the workpiece passes through these rolling mill stands one after another along a uniform conveying direction for the rolling mill stands, so that the workpiece is rolled one after another in the rolling mill stands of the rolling mill train.

[0013] -The rolling mill train has a control device that controls the rolling mill stand of the rolling mill train. Background Technology

[0014] Rolled products made of metal—especially metal strip—are often rolled in multi-stand mill runs. Maintaining a predetermined profile and flatness is particularly important when rolling metal strip. Typically, profile and flatness cannot be influenced independently of each other. In particular, they are determined by the shape of the mill gap before the measurement point.

[0015] To maintain profile and flatness, corresponding control devices for profile and flatness (or shape and flatness) are known. These control devices can, for example, act on mill bending, mill pivoting, mill displacement, and / or mill cooling of a given mill stand.

[0016] If control intervention is implemented through a regulating device, i.e., changing the direction of the mill gap, the profile of the metal strip flowing out of a given mill stand will change. Simultaneously, the profile of the metal strip flowing out of a given mill stand is also the profile of the metal strip entering subsequent mill stands. Therefore, unless the mill gap direction of subsequent mill stands is also changed accordingly, the flatness of the metal strip after those subsequent mill stands will change.

[0017] A similar situation applies in the other direction. If the profile of the metal strip after a given mill stand is altered by adjusting the mill gap accordingly, the flatness after that mill stand will also change unless the preceding mill stand is adapted accordingly.

[0018] Therefore, if the profile dimensions of a strip are to be adjusted after a specific mill stand in a rolling mill train (e.g., after the last mill stand in the rolling mill train), at least that mill stand must be adjusted. An earlier European patent application, 18198437.8 (filed October 3, 2018), which was not published on the filing date of this invention, describes a method of operating a rolling mill train with multiple mill stands, wherein the mill stands preceding the specific mill stand can also be adjusted to dynamically adjust the profile and shape of the metal strip to their respective target dimensions. This shifts flatness errors into the interstand region between the specific mill stand and the mill stands arranged upstream of it.

[0019] To avoid flatness errors in the inter-stand region, the profiles in the upstream mill stands can be adjusted and adapted accordingly. This further shifts the flatness error into the front region of the mill train. However, when rolling in the front mill stands of the mill train, the metal strip is often still quite thick, causing lateral material flow during rolling and thus preventing flatness errors. However, the dynamics of the control device depend on the transport time of the metal strip from the first participating mill stand to the measurement point. Due to the large distance and the resulting long transport time, in the prior art, it is not possible to quickly and accurately establish the profile in a large mill train with, for example, seven mill stands. Summary of the Invention

[0020] The objective of this invention is to create the possibility of setting the profile of a rolled piece with high dynamics, while minimizing flatness errors in the interstand region.

[0021] This task is accomplished by a method of operating a rolling mill train having the features of claim 1. An advantageous design of this method is the subject of dependent claims 2 to 5.

[0022] According to the present invention, an operating method for a rolling mill train of the type described at the beginning of this article is designed as follows:

[0023] - The control device determines the corresponding temporary adjustment parameters for the upstream mill stand by filtering the characteristic parameters or the corresponding intermediate parameters obtained from the characteristic parameters at the corresponding frequencies.

[0024] - This frequency filtering design ensures that, when the corresponding temporary adjustment parameters of the upstream mill stand are known, only the frequency components of the characteristic parameters below the corresponding threshold frequency are included.

[0025] -Regarding the arrangement of the mill train along the conveying direction, with respect to a certain number of mill stands upstream of a given mill stand, and with respect to the conveying direction, the limiting frequency remains the same or increases from one mill stand to the next.

[0026] Therefore, within the scope of this invention, the frequency of profile changes is divided. Rapid profile changes are compensated for with high dynamics in the rear mill stands of the rolling mill train, while slow profile changes are shifted to the front mill stands of the rolling mill train. In this case, the further forward the shift occurs, the slower the profile change becomes. The result is high dynamics of the control device, wherein flatness errors in the inter-stand regions between the mill stands of the rolling mill train are kept small simultaneously. Furthermore, the load on the rear mill stands is reduced.

[0027] Control devices typically determine temporary adjustment parameters for a given mill stand in a rolling mill train based on characteristic parameters, particularly through frequency filtering of these characteristic parameters. For mill stands located upstream, this determination is always achieved through frequency filtering. In this case, it is feasible for the control device to determine the temporary adjustment parameters for upstream mill stands by frequency filtering of the characteristic parameters. However, it is preferable for the control device to determine the temporary adjustment parameters for upstream mill stands by frequency filtering of the corresponding intermediate parameters. In this case, the control device preferably determines the corresponding intermediate parameters based on the final adjustment parameters for mill stands located directly downstream along the conveying direction. Determining the corresponding intermediate parameters has the particular advantage of making the filtering easier to parameterize. Furthermore, the residual, unavoidable unevenness of the strip in the inter-stand region is generally less than the error obtained from the characteristic parameters themselves.

[0028] Preferably, the control device determines the final adjustment parameters for the corresponding mill stand based on the temporary adjustment parameters and corresponding correction parameters for that mill stand. In this case, the control device determines the corresponding correction parameters based on the temporary adjustment parameters of the mill stands directly upstream, viewed along the conveying direction. Thus, when operating the corresponding mill stand, contour changes caused by one or more mill stands located upstream can be taken into account.

[0029] The control device preferably delays the corresponding correction parameter by a corresponding delay time relative to the temporary adjustment parameter of the mill stand directly upstream when viewed along the conveying direction. This allows the corresponding correction parameter to be coordinated with the corresponding temporary adjustment parameter in time.

[0030] Preferably, the control device limits the final adjustment parameter by means of a corresponding limiting element. This allows for particular consideration of the actuator's adjustment limits.

[0031] Furthermore, the task is accomplished by a control program having the features of claim 6. According to the invention, the execution of the program code causes the control device to control the rolling mill train according to an operating method according to the invention.

[0032] The task is accomplished by a control device for a rolling mill train having the features of claim 7. An advantageous design of this control device is the subject of dependent claims 8 to 12.

[0033] According to the present invention, a control device for a rolling mill train of the type described at the beginning of this article is designed in the following manner:

[0034] - The known path of the upstream mill stand has a frequency filter. With the help of this frequency filter, the control device learns the corresponding temporary adjustment parameters for the upstream mill stand by performing corresponding frequency filtering on the characteristic parameters or the corresponding intermediate parameters obtained from the characteristic parameters.

[0035] - The frequency filter is constructed such that, when the corresponding temporary adjustment parameters for the upstream mill stand are known, only the frequency components of the characteristic parameters below the corresponding threshold frequency are included, and

[0036] -Regarding the arrangement of the mill train along the conveying direction, in relation to a certain number of mill stands upstream of a given mill stand, and considering that the limiting frequency remains the same or increases from one mill stand to the next along the conveying direction, and

[0037] - The known path for a given mill stand is thus constructed such that, when the temporary adjustment parameters for the given mill stand are known, at least the frequency component of the characteristic parameter is higher than the limiting frequency of the mill stand directly upstream of the given mill stand when viewed along the conveying direction.

[0038] Therefore, similar to the operation method, the frequency of profile changes is divided so that the rapid changes of the profile in the rear mill stand of the mill train are compensated with high dynamics, while the slow changes of the profile are transferred to the front mill stand of the mill train.

[0039] Preferably, the control device transmits characteristic parameters to the known path of a specific mill stand for the mill train. Furthermore, the control device preferably includes an intermediate block, by which it obtains corresponding intermediate parameters for the upstream mill stands based on the final adjustment parameters for the downstream mill stands arranged directly along the conveying direction. This achieves high dynamics of the control device. Additionally, it keeps the flatness error in the inter-stand area between mill stands in the mill train to a minimum. Ultimately, the load on the rear mill stands is reduced.

[0040] Preferably, the known path has nodes, where the control device learns the corresponding final adjustment parameters by adding corresponding temporary adjustment parameters and corresponding correction parameters for the corresponding mill stand. In this case, the control device also has a bridge element, by which the control device learns the corresponding correction parameters based on the final adjustment parameters of the mill stands directly arranged upstream, viewed along the conveying direction. Thus, when operating the corresponding mill stand, the profile changes caused by one or more mill stands arranged upstream can be taken into account.

[0041] The preferred bridge element has a delay element, by means of which the control device delays the corresponding correction parameter relative to the final adjustment parameter of the mill stand directly upstream in the conveying direction by a corresponding delay time. This allows the corresponding correction parameter to be coordinated with the corresponding temporary adjustment parameter in time.

[0042] Preferably, the known path has a corresponding limiting element, by which the control device limits the corresponding final adjustment parameter. This allows for particular consideration of the actuator's adjustment limits.

[0043] According to the present invention, the control device is preferably configured as a software programmable device through the implementation of the control program.

[0044] Furthermore, this task is accomplished by a rolling mill train having the features of claim 13. According to the invention, in a rolling mill train of the type described at the beginning of this article, the control device is configured as a control device according to the invention. Attached Figure Description

[0045] The above-described features, characteristics, and advantages of the present invention, as well as the ways and means of realizing them, will be more clearly and obviously explained in connection with the following description of the embodiments, and in more detail in conjunction with the accompanying drawings. Herein are illustrated in the diagrams:

[0046] Figure 1 A rolling mill train for rolling flat sections is shown.

[0047] Figure 2 The rear mill stand of the rolling mill train is shown.

[0048] Figure 3 The image shows multiple mill stands of a rolling mill train and an associated control unit.

[0049] Figure 4 The diagram shows multiple mill stands of a rolling mill train and a replacement, associated control unit.

[0050] Figure 5 It shows Figure 3 Variations,

[0051] Figure 6 It shows Figure 4 Variations and

[0052] Figure 7 The known path is shown. Detailed Implementation

[0053] according to Figure 1An elongated strip 2 is rolled in rolling mill 1. Strip 2 is typically a flat strip, particularly a strip. However, in some cases it can be other types of elongated strips, such as profiles. These profiles can be, for example, I-sections, H-sections, T-sections, etc. The material of strip 2 is typically steel, and in some cases aluminum. However, in some cases it can also be a strip 2 made of another metal, such as copper.

[0054] The rolled piece 2 is typically hot-rolled in mill train 1. For example, mill train 1 can be a finishing mill train for hot-rolling metal strip. However, cold rolling is not excluded. Regardless of their other design features, mill train 1 has multiple mill stands 3a to 3f. Figure 1 The diagram shows a total of six mill stands 3a to 3f. However, mill train 1 can also have a greater number of mill stands 3a to 3f, such as seven or eight. Similarly, mill train 1 can also have a smaller number of mill stands 3a to 3f, such as three, four, or five. The key point is that there are at least two mill stands 3a to 3f and the workpiece 2 passes through the mill stands 3a to 3f consecutively. The associated transport direction x is uniform for the mill stands 3a to 3f. The workpiece 2 is rolled while passing through the respective mill stands 3a to 3f, thus reducing its cross-section.

[0055] The term "passing successively" should not mean that the rolled piece 2 is first fully rolled in one of the rolling mill stands 3a to 3f and then fully rolled in the next of the rolling mill stands 3a to 3f, etc. Rather, this term is used to indicate that, although the rolled piece 2 as a whole is rolled simultaneously in multiple rolling mill stands 3a to 3f, each individual segment of the rolled piece 2 passes through the rolling mill stands 3a to 3f sequentially and consecutively. Furthermore, in Figure 1 And also Figure 2 Only the working mills in mill stands 3a to 3f are shown. However, mill stands 3a to 3f typically have other mills, especially in the case of a four-mill stand design with a support mill, or in the case of a six-mill stand design with a support mill and an intermediate mill.

[0056] With regard to the terms "arranged upstream" and "arranged downstream" as used below, they invariably refer to the order in which the rolled piece 2 passes through mill stands 3a to 3f. For example, mill stands 3a and 3b are arranged upstream of mill stand 3c, wherein mill stand 3b is directly arranged upstream of mill stand 3c and mill stand 3a is indirectly arranged upstream of mill stand 3c. Similarly, mill stands 3d, 3e, and 3f are arranged downstream of mill stand 3c, wherein mill stand 3d is directly arranged downstream of mill stand 3c and mill stands 3e and 3f are indirectly arranged downstream of mill stand 3c. Similar embodiments apply to the relationships between other mill stands 3a to 3f.

[0057] The rolling mill train 1, and therefore the rolling mill stands 3a to 3f, are controlled by a control device 4. The control device 4 is typically configured as a software-programmable control device. The control device 4 is programmed using a control program 5. The control program 5 includes program code 6, which can be executed by the control device 4. During operation, the control device 4 executes program code 6. The execution of program code 6 by the control device 4 causes the control device 4 to control the rolling mill train 1 according to an operating method, which will be described in detail below.

[0058] Control device 4 has a known parameter δQ, which represents the characteristic of the cross-sectional change of the rolled piece 2 that should flow from a specific mill stand 3a to 3f of mill train 1. The specific mill stands 3a to 3f can be the last mill stand 3f of mill train 1. However, it is assumed below that it is the penultimate mill stand 3e of mill train 1. If the rolled piece 2 is strip, the parameter δQ typically represents the characteristic of the profile change. This characteristic parameter δQ can be the desired cross-sectional change. Alternatively, it can be a parameter from which the cross-sectional change can be known. An example of such a parameter is flatness, from which the profile must be changed in order to change the flatness. Alternatively, it can also be a parameter that occurs during the control of mill stands 3a to 3f given a cross-sectional change. It is assumed below that the characteristic parameter δQ is the change preset value itself. The characteristic parameter δQ is therefore directly called the change preset value. Of course, if another value is preset for the characteristic parameter δQ, which can be converted into the desired cross-sectional change, then the entire implementation method is also applicable.

[0059] It is feasible to preset the change in the control device 4 by an operator (not shown) using corresponding control commands. Alternatively, according to Figure 2 For example, a feasible approach is to arrange a measuring device 7 at a measurement location to detect the actual parameter M of the rolled piece 2, such as detecting the profile and / or flatness in the case of a flat rolled piece 2. If the actual parameter M is detected, the detected actual parameter M, along with the associated nominal parameter M*, can be transmitted to the control device 8. In this case, the control device 8 can determine the change in the preset value δQ based on the actual parameter M and the nominal parameter M*, particularly based on the deviation between the actual parameter M and the nominal parameter M*. The control device 8 can be a component of the control device 4.

[0060] As already mentioned, within the scope of this embodiment, it is assumed that the change in the preset value δQ affects the penultimate mill stand 3e of mill train 1. This design is particularly reasonable within the scope of the previously mentioned, unpublished European patent application 18,198,437.8, filed October 3, 2018. However, the effect on the penultimate mill stand 3e of mill train 1 is not mandatory. The change in the preset value δQ can also affect the other mill stands 3a to 3f of mill train 1, in addition to the first mill stand 3a.

[0061] Control device 4 according to Figure 3 The display has a certain number of known paths 9b to 9e. One of the known paths 9b to 9e—specifically, known path 9e—is associated with the mill stand 3e to which the variable preset value δQ acts. Furthermore, a certain number of mill stands 3b to 3d arranged upstream of mill stand 3e are also associated with corresponding known paths 9b to 9d. The number of upstream mill stands 3b to 3d can be adjusted as needed, with one known path 9b to 9d existing for each of these mill stands within the framework of the present invention. This number is at least 1, but typically it is greater than 1. This number can be so large that even for the foremost mill stand 3a of mill train 1, there is a known path. However, it is assumed below that, looking along the conveying direction x, a known path 9b exists for the first mill stand 3b of mill train 1.

[0062] The following embodiments, without exception, relate to a defined mill stand 3e and mill stands 3b to 3d arranged upstream of the defined mill stand 3e, for which a known path 9b to 9e exists, here therefore mill stands 3b to 3e. The first and last mill stands 3a and 3f of mill series 1 are not considered. Generally, this applies within the scope of the invention to all mill stands 3a to 3f arranged downstream of the defined mill stand 3e and all mill stands 3a to 3f arranged upstream of the first mill stand 3a, for which no known path exists. This fact applies not only to... Figure 3 Also applicable Figures 4 to 7 For clarity, it should also be mentioned that the control device 4 also obtains the adjustment parameters for the mill stands 3a and 3f. However, the mill stands 3a and 3f—in the current case, i.e., the first and last mill stands 3a and 3f of mill train 1—are not included in this invention.

[0063] In the known paths 9b to 9e, the control device 4 learns a temporary adjustment parameter Sb to Se based on a change preset value δQ—which is determined for a specific mill stand 3e—and also for the mill stands 3b to 3d located upstream. This learning can, for example, be performed in the known blocks 10b to 10e.

[0064] Control device 4 operates mill stands 3b to 3e according to the corresponding final adjustment parameters Sb' to Se'. The final adjustment parameters Sb' to Se' affect the cross-section of the rolled piece 2 flowing out from the corresponding mill stands 3b to 3e of mill row 1. The final adjustment parameters Sb' to Se' can affect the corresponding mill stands 3b to 3e as needed. For example, they can affect mill bending, mill cooling, mill lubrication, mill axial displacement, wedge adjustment, and others in the case of flat rolled pieces 2.

[0065] Control device 4 obtains the final adjustment parameters Sb' to Se' using the corresponding temporary adjustment parameters Sb to Se. Figure 3 Within the scope of the design scheme, the final adjustment parameters Sb' to Sd' are directly and indirectly consistent with the temporary adjustment parameters Sb to Sd. Even if numerical changes are made, the temporary adjustment parameters Sb to Se and the final adjustment parameters Sb' to Se' are at least generally of the same kind. If, purely exemplarily, mill bending is known as a temporary adjustment parameter Sd, then the mill bending can be increased or decreased during the process of knowing the final adjustment parameter Sd'. However, the type of adjustment parameter, i.e., mill bending, remains unchanged.

[0066] It is known that blocks 10b to 10d each have frequency filters 11b to 11d. A variable parameter δQ is supplied to the corresponding frequency filters 11b to 11d. With the help of frequency filters 11b to 11d, the control device 4 obtains the corresponding temporary adjustment parameters Sb to Sd by filtering the corresponding frequency of the variable preset value δQ.

[0067] Low-pass filtering is performed using frequency filters 11b to 11d. Signals input to the corresponding frequency filters 11b to 11d remain unchanged or approximately unchanged below their respective threshold frequencies fb to fd. Signals input to the corresponding frequency filters 11b to 11d above their respective threshold frequencies fb to fd are filtered out, so that they are no longer included in the output signals of the corresponding frequency filters 11b to 11d. From a structural perspective, frequency filters 11b to 11d can be constructed as needed. For example, they can be constructed as Cauer filters or Butterworth filters. Other design schemes are feasible, such as designing them as PT1 filters.

[0068] If necessary, corresponding multipliers 12b to 12d can be arranged upstream of the corresponding frequency filters 11b to 11d. In this case, the variation parameter δQ is multiplied by the corresponding scaling factors Kb to Kd in the corresponding multipliers 12b to 12d before being fed to the corresponding frequency filters 11b to 11d. Alternatively, multipliers 12b to 12d can be arranged downstream of their respective frequency filters 11b to 11d. In this case, it is not the input signal of the corresponding frequency filters 11b to 11d—i.e., the variation parameter δQ—that is multiplied by the corresponding scaling factors Kb to Kd, but rather the output signal of the corresponding frequency filters 11b to 11d. In this case, the temporary adjustment parameters Sb to Sd are aligned with the output signal of the frequency filters 11b to 11d after multiplication by the corresponding scaling factors Kb to Kd. The scaling factors Kb to Kd can be determined, in particular, by the sensitivity of the mill stands 3b to 3d.

[0069] Frequency filters can be linear or nonlinear. In the case of a linear frequency filter, the arrangement of multipliers 12b to 12d upstream of frequency filters 11b to 11d is equivalent to their arrangement downstream of frequency filters 11b to 11d. However, different results are obtained in the case of a nonlinear frequency filter.

[0070] Frequency filtering is consistently applied to mill stands 3b to 3d, which are located upstream of a defined mill stand 3e. A completely similar approach can be taken for the known path 9e. According to... Figure 3 The demonstration also adopted this approach. A frequency filter 11e and a multiplier 12e may also exist for the known path 9e and the associated known block 10e, and if necessary, a multiplier 12e as well. The frequency filter for the known block 10e is designed in this case such that, when the temporary adjustment parameter Se for a given mill stand 3e is known, it includes at least a frequency component with a changing preset value δQ that is higher than the limiting frequency fd of the mill stand 3d.

[0071] However, this is not mandatory for the known path 9e. Alternatively, it is equally feasible to not perform frequency filtering at all; that is, to use the variable preset value δQ—after multiplying it, if necessary, with the associated scaling factor Ke—as a temporary adjustment parameter Se. In this case, the temporary adjustment parameter Se itself contains a frequency component of the variable preset value δQ that is higher than the limiting frequency fd of the mill stand 3d.

[0072] Frequency filters 11b to 11d (and 11e if necessary) are constructed such that, when the corresponding temporary adjustment parameters Sb to Se are known, they contain only frequency components lower than the corresponding limiting frequencies fb to fd or fe, respectively, with varying preset values ​​δQ. The corresponding limiting frequencies fb to fd of the corresponding upstream mill stands 3b to 3d are preferably determined by the transmission time from the corresponding upstream mill stands 3b to 3d to the determined mill stand 3e. The limiting frequency of the determined mill stand 3e is either practically infinite (if no filtering is performed) or (if filtering is performed) so high that it has virtually no effect, i.e., the temporary adjustment parameter Se contains the signal component with the highest practically usable frequency.

[0073] In this case, it applies that the limiting frequency fb of mill stand 3b is less than the limiting frequency fe of mill stand 3e. For example, the limiting frequency fb can be 1 Hz, while it is 20 Hz for mill stand 3e. Typically, the limiting frequencies fb to fe increase from mill stand 3b to 3e to mill stand 3b to 3e respectively. However, at least the limiting frequencies fb to fe do not decrease from mill stand 3b to 3e to mill stand 3b to 3e. If, according to the example given above, the limiting frequency fb of mill stand 3b is 1 Hz and the limiting frequency fe for mill stand 3e is 20 Hz, then, for example, the limiting frequency fc of mill stand 3c can be 3 Hz and the limiting frequency fd of mill stand 3d can be 8 Hz. However, these values ​​should not be interpreted restrictively. They are only used to better illustrate the principle.

[0074] Figure 4 It shows Figure 3 This is an alternative approach. Therefore, the following discussion will only focus on... Figure 3 The main difference.

[0075] exist Figure 4 In the process of doing so - just like in Figure 3 In that case - the temporary adjustment parameters Sb to Se are obtained, and from them the final adjustment parameters Sb' to Se' are obtained. Figure 3 The approaches are different, in Figure 3 In this case, for all participating rolling mill stands 3b to 3e, the temporary adjustment parameters Sb to Se are directly obtained based on the changed preset value δQ, while... Figure 4In this process, the temporary adjustment parameter Se is obtained only for the specific mill stand 3e. The change in the preset value δQ is directly transmitted to the acquisition path 9e. The corresponding intermediate parameters Zb to Zd are transmitted to the other acquisition paths 9b to 9d. The control device 4 thus obtains the temporary adjustment parameters Sb to Sd for the upstream mill stands 3b to 3d by frequency filtering of the corresponding intermediate parameters Zb to Zd. The control device 4 then obtains the corresponding intermediate parameters Zb to Zd based on the final adjustment parameters Sc' to Se' for the downstream mill stands 3c to 3e, respectively. This acquisition is performed in intermediate blocks 13c to 13e, which are components of the acquisition paths 9c to 9e. In the simplest case, the intermediate blocks 13c to 13e are constructed as simple sensors (Abgriffe).

[0076] according to Figure 3 and 4 In the demonstration, it is feasible for the control device 4 to consider only the corresponding temporary adjustment parameters Sc to Se when it learns the corresponding final adjustment parameters Sc' to Se'. However, preferably... Figure 3 and 4 Design scheme based on Figure 5 and 6 The display is used for modification. Figure 5 and 6 Within the scope of the modification, the control device 4 determines the corresponding final adjustment parameters Sc' to Se' for the corresponding mill stands 3c to 3e based on the temporary adjustment parameters Sc to Se and the corresponding correction parameters Sc'' to Se'' for the corresponding mill stands 3c to 3e. In particular, it is determined that paths 9c to 9e have nodes 14c to 14e, in which the control device 4 determines the corresponding final adjustment parameters Sc' to Se' by adding the corresponding temporary adjustment parameters Sc to Se and the corresponding correction parameters Sc'' to Se'' for the corresponding mill stands 3c to 3e.

[0077] The control device 4 obtains the corresponding correction parameters Sc'' to Se'' based on the temporary adjustment parameters Sb to Sd of the mill stands 3b to 3d directly arranged upstream. Specifically, the control device 4 has bridge elements 15c to 15e to which the temporary adjustment parameters Sb to Sd of the mill stands 3b to 3d directly arranged upstream are fed, and by means of these bridge elements, the control device 4 obtains the corresponding correction parameters Sc'' to Se''. In particular, the control device 4 can perform scaling, for example, with corresponding scaling factors Kc' to Ke' in the multipliers 16c to 16e of the bridge elements 15c to 15e. The scaling factors Kc' to Ki' can be determined—similar to the scaling factors Kb to Kd—particularly by the sensitivity of the mill stands 3b to 3e.

[0078] An exception to this approach applies to the foremost mill stand 3b, which has known paths 9b to 9d. Its temporary adjustment parameter Sb is no longer corrected using the correction parameter during the process of learning the associated final adjustment parameter Sb'. For the purposes of this invention, this also applies to the case where at least one mill stand 3a of the mill row 1—here, mill stand 3a—is arranged upstream of the corresponding mill stand 3b.

[0079] As in Figure 5 and 6 As shown, bridge elements 15c to 15e preferably also have delay mechanisms 17c to 17e. With the aid of delay mechanisms 17c to 17e, control device 4 delays the corresponding correction parameters Sc'' to Se'' by a corresponding delay time Tc to Te relative to the temporary adjustment parameters Sb to Sd of the mill stands 3b to 3d directly arranged upstream. The corresponding delay time Tc to Te is generally determined by the corresponding transport time required for the workpiece 2 to traverse the sections from the mill stands 3b to 3d to the respective mill stands 3c to 3e. The corresponding delay time Tc to Te is therefore generally determined by the distance between the respective mill stands 3c to 3e and the mill stands 3b to 3d directly arranged upstream, and the corresponding rolling speeds vc to ve, at which the workpiece 2 flows out of or into the respective mill stands 3c to 3e directly arranged upstream. If necessary, the corresponding delay times Tc to Te can be scaled from the corresponding transmission time using a corresponding scaling factor. The corresponding scaling factor is typically between 0.5 and 2.0, and in most cases between 0.8 and 1.25. The scaling factor for delay mechanisms 17c to 17e can be uniformly or individually determined.

[0080] exist Figures 3 to 6 Frequency filtering is performed in the corresponding frequency filters 11b to 11e within the scope of the design scheme. Figure 7 One possible design for obtaining path 9c is shown. Similar implementations apply to obtaining paths 9b, 9d, and 9e.

[0081] according to Figure 7 As shown in the diagram, block 10c can be arranged downstream of limiting element 18. In this case, control device 4 limits the output signal of knowing block 10c by means of limiting element 18. If node 14c exists, then limiting element 18 is arranged downstream of node 14c in the signal flow. If intermediate block 13c exists, then limiting element 18 is arranged upstream of intermediate block 13c in the signal flow.

[0082] Control device 4, as already mentioned, is typically configured as a software-programmable control device. The operation of control device 4 is thus caused by control program 5. Control program 5 and its program code 6 are thus caused by the implementation of control device 4, which implements the aforementioned functional units, such as paths 9b to 9e, intermediate blocks 13c to 13e, or bridge elements 15c to 15e, as software blocks.

[0083] This invention offers numerous advantages. In particular, the adjustment intervention for compensating for changes in the preset value δQ is distributed across multiple mill stands 3b to 3e, thus requiring only minimal manipulation of each mill stand 3b to 3e. High dynamics can still be achieved when compensating for changes in the preset value δQ.

[0084] Although the invention has been described and illustrated in more detail by way of preferred embodiments, the invention is not limited to the disclosed examples, and those skilled in the art can derive other variations therefrom without departing from the scope of protection of the invention.

[0085] List of reference numerals

[0086] 1 Rolling Mill Train

[0087] 2 Rolled parts

[0088] 3a to 3f rolling mill stands

[0089] 4. Control device

[0090] 5 Control Procedure

[0091] 6. Program Code

[0092] 7. Measuring device

[0093] 8. Control device

[0094] Paths from 9b to 9e are known

[0095] Blocks 10b to 10e

[0096] 11b to 11e frequency filters

[0097] 12b to 12e multipliers

[0098] 13c to 13e intermediate blocks

[0099] Nodes 14c to 14e

[0100] 15c to 15e bridge elements

[0101] 16c to 16e multipliers

[0102] 17c to 17e Delay mechanism

[0103] 18. Limiting elements

[0104] fb to fe limiting frequency

[0105] Kb to Ke scaling factor

[0106] Scaling factor from Kc' to Ke'

[0107] M actual parameter

[0108] M* Rated Parameter

[0109] Sb to Se temporary adjustment parameters

[0110] Sb' to Se' final adjustment parameters

[0111] Sc'' to Se'' Correction parameters

[0112] Tc to Te delay time

[0113] VC to VE rolling speed

[0114] x Teleportation direction

[0115] Intermediate parameters from Zb to Zd

[0116] δQ variation preset value / characteristic parameter

Claims

1. A method for operating a rolling mill train (1) for rolling a workpiece (2) made of metal, -in, The rolling mill train (1) has multiple rolling mill stands (3a to 3f), and the workpiece (2) passes through the rolling mill stands one after another along a uniform conveying direction (x) for the rolling mill stands (3a to 3f), so that the workpiece (2) is rolled one after another in the rolling mill stands (3a to 3f). - Wherein, based on a characteristic parameter (δQ) representing the cross-sectional change of the rolled piece (2) that should flow out from a determined mill stand (3e) of the mill train (1), the control device (4) of the mill train (1) first obtains the corresponding temporary adjustment parameters (Sb to Se) for the mill stand (3e) and a certain number of mill stands (3b to 3d) of the mill train (1) arranged upstream of the mill stand (3e) in the conveying direction (x), and obtains the corresponding final adjustment parameters (Sb' to Se') using the corresponding temporary adjustment parameters (Sb to Se). - wherein the corresponding final adjustment parameters (Sb' to Se') affect the cross-section of the rolled piece (2) flowing out from the corresponding mill stands (3b to 3e) of the mill train (1), - wherein the control device (4) operates the mill stands (3b to 3e) according to the corresponding final adjustment parameters (Sb' to Se'). It is characterized in that -The control device (4) obtains the corresponding temporary adjustment parameters (Sb to Sd) for the upstream rolling mill stands (3b to 3d) by frequency filtering the characteristic parameter (δQ) or the corresponding intermediate parameters (Zb to Zd) obtained from the characteristic parameter (δQ). - The frequency filtering is designed in such a way that, when the corresponding temporary adjustment parameters (Sb to Sd) for the upstream mill stands (3b to 3d) are known, only the frequency components of the characteristic parameter (δQ) below the corresponding threshold frequency (fb to fd) are included. -Regarding the arrangement of the mill train (1) along the conveying direction (x) on a certain number of mill stands (3b to 3d) upstream of a defined mill stand (3e), and viewed along the conveying direction (x), the limiting frequency (fb to fd) remains the same or increases from mill stand (3b to 3d) to mill stand (3b to 3d), and The control device (4) determines the temporary adjustment parameter (Se) for the determined mill stand (3e) in such a way that, when the temporary adjustment parameter (Se) for the determined mill stand (3e) is known, it includes at least the frequency component of the characteristic parameter (δQ) that is higher than the limiting frequency (fd) of the mill stand (3d) directly upstream of the determined mill stand (3e) when viewed along the conveying direction (x).

2. The operating method according to claim 1, It is characterized in that -The control device (4) determines the temporary adjustment parameter (Se) for a specific mill stand (3e) of the mill train (1) based on the characteristic parameter (δQ). The control device (4) determines the temporary adjustment parameters (Sb to Sd) for the upstream mill stands (3b to 3d) by frequency filtering of the corresponding intermediate parameters (Zb to Zd). - The control device (4) obtains the corresponding intermediate parameters (Zb to Zd) based on the final adjustment parameters (Sc' to Se') for the rolling mill stands (3c to 3e) directly arranged downstream as viewed along the conveying direction (x).

3. The operating method according to claim 2, Its features are, The control device (4) obtains the temporary adjustment parameter (Se) for a given mill stand (3e) of the mill train (1) by frequency filtering of the characteristic parameter (δQ).

4. The operating method according to claim 1 or 2, It is characterized in that The control device (4) determines the corresponding final adjustment parameters (Sc' to Se') for the corresponding rolling mill stands (3c to 3e) based on the temporary adjustment parameters (Sc to Se) and the corresponding correction parameters (Sc' to Se') for the corresponding rolling mill stands (3c to 3e). -The control device (4) obtains the corresponding correction parameters (Sc” to Se”) based on the temporary adjustment parameters (Sb to Sd) of the mill stands (3b to 3d) directly arranged upstream along the conveying direction (x).

5. The operating method according to claim 4, It is characterized in that The control device (4) delays the corresponding correction parameters (Sc” to Se”) relative to the temporary adjustment parameters (Sb to Sd) of the mill stands (3b to 3d) directly arranged upstream as viewed along the conveying direction (x).

6. The operating method according to any one of the preceding claims, It is characterized in that The control device (4) limits the final adjustment parameter (Sb' to Se') by means of a corresponding limiting element (18).

7. Control program products, among which, The control program product includes program code (6) which can be executed by a control device (4) for a mill train (1) having multiple mill stands (3a to 3f), wherein the execution of the program code (6) causes the control device (4) to control the mill train (1) according to the operating method according to any one of the preceding claims.

8. A control device for a rolling mill train (1) used for rolling a workpiece (2) made of metal, wherein, The rolling mill train (1) has multiple rolling mill stands (3a to 3f), and the workpiece (2) passes through the rolling mill stands one after another along a uniform conveying direction (x) for the rolling mill stands (3a to 3f), so that the workpiece (2) is rolled one after another in the rolling mill stands (3a to 3f). -The control device has a known path (9b to 9e), by means of which, based on a characteristic parameter (δQ) representing the change in cross-section of the rolled piece (2) that should flow from a determined mill stand (3e) of the mill train (1), the control device first knows the corresponding temporary adjustment parameters (Sb to Se) for the mill stand (3e) and a certain number of mill stands (3b to 3d) of the mill train (1) arranged upstream of the mill stand (3e) in the conveying direction (x), and then knows the corresponding final adjustment parameters (Sb' to Se') using the corresponding temporary adjustment parameters (Sb to Se). - wherein the corresponding final adjustment parameters (Sb' to Se') affect the cross-section of the rolled piece (2) flowing out from the corresponding mill stands (3b to 3e) of the mill train (1), - wherein the control device operates the mill stands (3b to 3e) according to the corresponding final adjustment parameters (Sb' to Se'). It is characterized in that - The known paths (9b to 9d) of the upstream mill stands (3b to 3d) have frequency filters (11b to 11d). With the aid of these frequency filters, the control device determines the corresponding temporary adjustment parameters (Sb to Sd) for the upstream mill stands (3b to 3d) by frequency filtering the characteristic parameter (δQ) or the corresponding intermediate parameters (Zb to Zd) obtained from the characteristic parameter (δQ). - The frequency filters (11b to 11d) are constructed such that, when the corresponding temporary adjustment parameters (Sb to Sd) for the upstream mill stands (3b to 3d) are known, only the frequency components of the characteristic parameter (δQ) below the corresponding threshold frequency (fb to fd) are included. -Regarding the arrangement of the mill train (1) along the conveying direction (x) on a certain number of mill stands (3b to 3d) upstream of a defined mill stand (3e), and viewed along the conveying direction (x), the limiting frequency (fb to fd) remains the same or increases from mill stand (3b to 3d) to mill stand (3b to 3d), and - The known path (9e) for a given mill stand (3e) is constructed such that, when the temporary adjustment parameter (Se) for the given mill stand (3e) is known, it includes at least the frequency component of the characteristic parameter (δQ) that is higher than the limiting frequency (fd) of the mill stand (3d) directly upstream of the given mill stand (3e) when viewed along the conveying direction (x).

9. The control device according to claim 8, It is characterized in that The control device transmits the characteristic parameter (δQ) to the known path (9e) for the determined mill stand (3e) of the mill train (1). The control device transmits the corresponding intermediate parameters (Zb to Zd) to the known paths (9b to 9d) for the upstream rolling mill stands (3b to 3d) and - The control device has an intermediate block (13c to 13e), by means of which the control device obtains the corresponding intermediate parameters (Zb to Zd) for the mill stands (3b to 3d) arranged upstream, based on the final adjustment parameters (Sc' to Se') for the mill stands (3c to 3e) arranged directly downstream as viewed along the conveying direction (x).

10. The control device according to claim 8 or 9, It is characterized in that - The known path (9c to 9e) has nodes (14c to 14e), in which the control device learns the corresponding final adjustment parameters (Sc' to Se') by adding corresponding temporary adjustment parameters (Sc to Se) and corresponding correction parameters (Sc” to Se”) for the corresponding mill stands (3c to 3e). - The control device has bridge elements (15c to 15e), by means of which the control device obtains the corresponding correction parameters (Sc” to Se”) based on the temporary adjustment parameters (Sb to Sd) of the mill stands (3b to 3d) directly arranged upstream along the conveying direction (x).

11. The control device according to claim 10, It is characterized in that The bridge elements (15c to 15e) have a delay mechanism (17c to 17e) by means of which the control device delays the corresponding correction parameter (Sc” to Se”) relative to the temporary adjustment parameter (Sb to Sd) of the mill stand (3b to 3d) directly arranged upstream in the conveying direction (x) by a corresponding delay time (Tc to Te).

12. The control device according to any one of claims 8 to 11, It is characterized in that The known path (9b to 9e) has a corresponding limiting element (18), by means of which the control device limits the corresponding final adjustment parameter (Sb' to Se').

13. The control device according to any one of claims 8 to 12, It is characterized in that The control device is configured as a software-programmable device.

14. For rolling mill trains producing flat rolled pieces (2), -in, The rolling mill train has multiple rolling mill stands (3a to 3f), and the workpiece (2) passes through the rolling mill stands one after another along a uniform conveying direction (x) for the rolling mill stands (3a to 3f), so that the workpiece (2) is rolled one after another in the rolling mill stands (3a to 3f). -The rolling mill train has a control device (4) that controls the rolling mill stands (3a to 3a) of the rolling mill train. 3f)， It is characterized in that The control device (4) is configured as the control device according to any one of claims 8 to 13.

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