EP3210682A1 - Complete compensation of roll eccentricities - Google Patents

Abstract

A rolling stand for rolling a flat rolled stock (3) of metal has an upper set of rolls (U) and a lower set of rolls (L) with corresponding work rolls (1U, 1L) and back-up rolls (2U, 2L). In a normal operation, the flat rolling stock (3) is rolled. In this case, a control device (4) continuously determines on the basis of first and second quantities (RUB, RLB, Õ1UB, Õ1LB, RUW, RLW, Õ2UW, Õ2LW) which are responsible for an eccentricity of the back-up rolls (2U, 2L) and the work rolls (1U, 1L ) of the roll stand as a function of a rotational position (ÕUB, ÕUW, ÕLB, ÕLW) of at least one roller (1U, 1L, 2U, 2L) of the rolling mill are characteristic of the rotational position (ÕUB, ÕUW, ÕLB, ÕLW) dependent compensation value (μ ). The control device (4) corrects a nominal roll gap value (s *) for the roll stand by the compensation value (μ) and applies the rolling stand accordingly.

Description

• wobei das Walzgerüst einen oberen Walzensatz und einen unteren Walzensatz aufweist,
• wobei der obere Walzensatz zumindest eine obere Arbeitswalze und eine obere Stützwalze aufweist und der untere Walzensatz zumindest eine untere Arbeitswalze und eine untere Stützwalze aufweist,
• wobei das Walzgerüst zumindest zeitweise in einem Normalbetrieb betrieben wird,
• wobei das Walzgerüst während des Walzens des flachen Walzguts im Normalbetrieb betrieben wird,
• wobei während des Walzens des flachen Walzguts eine Steuereinrichtung für das Walzgerüst kontinuierlich
  • -- anhand von ersten Größen, die für eine Teilexzentrizität der Stützwalzen des Walzgerüsts als Funktion einer Drehstellung mindestens einer Walze des Walzgerüsts charakteristisch sind, einen von der Drehstellung der mindestens einen Walze des Walzgerüsts abhängigen Kompensationswert ermittelt,
  • -- einen Walzspaltsollwert für das Walzgerüst um den ermittelten Kompensationswert korrigiert und
  • -- einen Walzspalt des Walzgerüsts entsprechend dem korrigierten Walzspaltsollwert einstellt,
  so dass das flache Walzgut mittels des Walzgerüsts entsprechend dem korrigierten Walzspaltsollwert gewalzt wird.

The present invention is based on an operating method for a rolling stand for rolling a flat rolled stock of metal,

• wherein the rolling stand comprises an upper set of rolls and a lower set of rolls,
• wherein the upper set of rollers has at least one upper work roll and one upper support roll, and the lower set of rolls has at least one lower work roll and a lower support roll,
• wherein the rolling mill is operated at least temporarily in a normal operation,
• wherein the rolling stand is operated during the rolling of the flat rolled stock in normal operation,
• during rolling of the flat rolled stock, a rolling stand controller continuously
  • on the basis of first quantities, which are characteristic of a partial eccentricity of the support rollers of the rolling stand as a function of a rotational position of at least one roller of the rolling stand, determines a compensation value dependent on the rotational position of the at least one roller of the rolling stand,
  • - a roll gap setpoint for the rolling stand corrected by the calculated compensation value and
  • setting a roll gap of the roll stand according to the corrected roll gap setpoint,
  so that the flat rolling stock is rolled by means of the roll stand according to the corrected set roll set value.

The present invention is further based on a computer program for a control device of a roll stand for rolling a flat rolled metal, wherein the computer program comprises machine code which is directly executable by the control device, wherein the processing of the machine code by the control device causes the Control device operates the rolling stand according to such an operating method.

The present invention is further based on a control device for a roll stand for rolling a flat rolled metal, wherein the control device is designed such that it operates the roll stand according to such an operating method.

The present invention is further based on a rolling stand for rolling a flat rolled stock of metal, wherein the rolling mill is controlled by such a control device.

An operating method of the type mentioned is, for example, from the US 3,881,335 A known. In this method of operation, the control means in the calibration operation controls the rolling stand initially such that at any fixed rotational position of the lower set of rolls, the upper set of rolls is stopped at a number of defined rotational positions, and then the work rolls are set to a predetermined position relative to one another via the back-up rolls. The respective occurring rolling force is recorded. From these values, quantities are determined which are characteristic of the eccentricity of the upper support roller as a function of the rotational position of the upper support roller. Any eccentricity of the upper work roll is neglected in this determination. In an analogous manner, the control device then controls the rolling stand in calibration mode such that at any fixed rotational position of the upper set of rolls the lower set of rolls is stopped at a number of defined rotational positions and then the work rolls are set to a predetermined position relative to one another via the back-up rolls. The respective occurring rolling force is recorded. From these values, quantities are determined which are characteristic of the eccentricity of the lower support roller as a function of the rotational position of the lower support roller. Any eccentricity of the lower work roll is neglected in this determination. In operation, the eccentricity in the upper and lower back-up rolls are corrected depending on their currently detected rotational position.

The known approach works well when the eccentricities of the work rolls are sufficiently small that they can actually be neglected. However, this is not always the case. Often also overlap, for example, an eccentricity of the upper support roller and an eccentricity of the upper work roll, so that the procedure of US 3,881,335 A either is not feasible or leads to erroneous results. In addition, the approach of the US 3,881,335 A implicitly assume that the bearings in which the work and back-up rolls are mounted are rolling bearings. Because only in such camps a load on the bearing at standstill is possible. However, modern rolling mills have oil plain bearings. Oil plain bearings may not be loaded with forces at standstill, as they are in rolling operation and also within the teaching of US 3,881,335 A when determining the eccentricities occur. The doctrine of US 3,881,335 A is therefore in principle not applicable in modern rolling stands in principle.

For the thickness control such as an AGC or a thickness monitor is often worked with dead bands, so that the controls are insensitive to a typical, usually fixed eccentricity. The accuracy of the control is reduced.

In the cold rolling area, methods are still known in which a model is created based on a frequency analysis of the rolling force signal and / or the course of the thickness. By means of the model is actively worked on the employment of the rolling stands to counteract the effect of eccentricity on the thickness of the rolling stock.

When rolling heavy plate rolled lengths are usually too short to perform such a frequency analysis. Furthermore, given the often given use of Twindrives, ie separate drives for the upper and the lower set of rolls of the rolling stand, additional variation possibilities. Furthermore, it is possible for backup rolls to slip relative to work rolls.

The object of the present invention is to provide possibilities by means of which a total eccentricity occurring when rolling a flat rolling stock can be corrected in all possible case constellations. In particular, the determination and the correction should be possible independently of which rolls of the roll stand the total eccentricity is caused to which part.

The object is achieved by an operating method for a rolling stand for rolling a flat metal rolling stock with the features of claim 1. Advantageous embodiments of the operating method according to the invention are the subject of the dependent claims 2 to 10.

According to the invention, an operating method of the type mentioned at the outset is configured in that the control device determines the compensation value not only on the basis of the first variables but also on the basis of second variables which characterize an eccentricity of the work rolls of the rolling mill as a function of a rotational position of at least one roll of the rolling stand are.

By doing so, any eccentricity can be compensated, regardless of whether it is caused by the work rolls or the backup rolls.

• für eine Anzahl von definierten Anfangsdrehstellungen sowohl des oberen Walzensatzes als auch des unteren Walzensatzes das Walzgerüst derart steuert, dass die obere Arbeitswalze auf der unteren Arbeitswalze aufliegt und die Walzen aneinander abrollen,
• während des Abrollens der Walzen aneinander über eine von der jeweiligen Anfangsdrehstellung ausgehende jeweilige Erfassungslänge jeweils einen von der Drehstellung der mindestens einen Walze abhängigen Verlauf eines für eine Änderung des Walzspaltes charakteristischen Signals erfasst und
• anhand der erfassten Verläufe die ersten und zweiten Größen ermittelt.

In a preferred embodiment of the present invention, the rolling mill is temporarily operated in a calibration, in which by means of the roll stand no flat rolling is rolled. In this case it is possible for the control device to be in calibration mode

• for a number of defined initial rotational positions of both the upper set of rolls and the lower set of rolls controls the roll stand such that the upper work roll rests on the lower work roll and roll the rolls together,
• during the rolling of the rollers against each other via a respective starting length starting from the respective starting rotational position respective detection length respectively dependent on the rotational position of the at least one roller course of a signal characteristic of a change of the roll gap detected and
• determined on the basis of the detected gradients, the first and second sizes.

In some cases, it will suffice for the number of initial rotational positions to be equal to 1, that is, the control means only for a single initial rotational position of the upper set of rollers in conjunction with a single initial rotational position of the lower set of rollers during the rolling of the rollers together over one of these two initial rotational positions Detection length detected the course of the characteristic of the change of the roll gap signal. This procedure may be sufficient, in particular, if the diameters of the support rollers differ from each other to a sufficient extent and the diameters of the work rolls differ from one another to a sufficient extent or only one eccentricity component is determined for the two support rollers together on the one hand and the two work rolls together. If, on the other hand, the diameters of the support rollers are almost identical and / or the diameters of the work rolls are nearly identical and a separate compensation component is to be determined for all four rollers, it is necessary in many cases for the number of initial rotational positions to be greater than one. The number of initial rotational positions may, for example, be 2, 3, 4,...

For example, if the number of initial rotational positions is two, after detecting the one course of one of the two sets of rollers relative to the other set of rollers is rotated by a predetermined Abrolllänge. The rolling length can correspond for example to half a revolution of one of the two rolls of the respective set of rolls. Thereafter, the other course is detected. It is therefore not important that the initial rotational positions of both sets of rolls are changed. Only a twisting relative to each other is required.

As an alternative to an independent determination of the first and second variables in a calibration operation, it is possible for the first and second variables of the control device to be predetermined by a higher-level control device or by an operator. For example, when grinding the rolls in a grinding shop, a corresponding determination of the first and second sizes can take place so that they are already known when the rolls are installed in the roll stand.

• dass die Drehstellungen sowohl der Stützwalzen als auch der Arbeitswalzen des Walzgerüsts erfasst und von der Steuereinrichtung entgegengenommen werden oder dass die Drehstellung nur der Arbeitswalzen oder nur der Stützwalzen des Walzgerüsts erfasst und von der Steuereinrichtung entgegengenommen werden und die Drehstellungen derjenigen Walzen, deren Drehstellungen nicht erfasst werden, von der Steuereinrichtung aus den Drehstellungen derjenigen Walzen, deren Drehstellungen erfasst werden, ermittelt werden,
• dass die ersten Größen die Exzentrizität der Stützwalzen in Abhängigkeit von der Drehstellung der Stützwalzen charakterisieren,
• dass die zweiten Größen die Exzentrizität der Arbeitswalzen in Abhängigkeit von der Drehstellung der Arbeitswalzen charakterisieren und
• dass die Steuereinrichtung den Kompensationswert in Abhängigkeit von der Drehstellung sowohl der Arbeitswalzen als auch der Stützwalzen ermittelt.
  Zum Walzen des flachen Walzguts müssen auf die Arbeitswalzen des Walzgerüsts Walzmomente ausgeübt werden. Dies erfolgt über Gerüstantriebe. In der Regel wirken die Gerüstantriebe direkt auf die Arbeitswalzen. In seltenen Einzelfällen werden die Stützwalzen angetrieben, so dass die Gerüstantriebe indirekt auf die Arbeitswalzen wirken. In der Regel weisen weiterhin die Gerüstantriebe Lagegeber auf, welche direkt Lagesignale ausgeben, für die Drehstellung des jeweiligen Gerüstantriebs charakteristisch sind. Anhand dieser Signale können
• gegebenenfalls in Verbindung mit Übersetzungen von zwischen den Gerüstantrieben und den angetriebenen Walzen angeordneten Getrieben - die Drehstellungen der angetriebenen Walzen direkt ermittelt werden. Für diese Walzen sind daher zum Erfassen von deren Drehstellung eigene Lagegeber nicht erforderlich. Die anderen Walzen - also in der Regel die Stützwalzen, in seltenen Einzelfällen ausnahmsweise die Arbeitswalzen - können Lagegeber zum Erfassen von deren Drehstellung aufweisen. Alternativ können die Drehstellungen aus den Drehstellungen der angetriebenen Walzen in Verbindung mit der Abrollbedingung ermittelt werden.

In a preferred embodiment of the operating method is provided

• that the rotational positions of both the back-up rolls and the work rolls of the roll stand are detected and received by the control device or that the rotational position of only the work rolls or only the support rollers of the roll stand detected and received by the control device and the rotational positions of those rollers whose rotational positions are not detected , are determined by the control device from the rotational positions of those rollers whose rotational positions are detected,
• that the first quantities characterize the eccentricity of the back-up rolls as a function of the rotational position of the back-up rolls,
• that the second sizes characterize the eccentricity of the work rolls as a function of the rotational position of the work rolls, and
• the control device determines the compensation value as a function of the rotational position of both the work rolls and the support rolls.
  To roll the flat rolling stock, rolling torques must be exerted on the work rolls of the rolling stand. This is done via scaffold drives. As a rule, the scaffolding drives act directly on the work rolls. In rare cases, the backup rollers are driven so that the scaffold drives act indirectly on the work rolls. As a rule, furthermore, the scaffolding drives have position sensors which output position signals directly, which are characteristic of the rotational position of the respective scaffold drive. Based on these signals can
• optionally in conjunction with gear ratios of gears arranged between the scaffold drives and the driven rollers - the rotational positions of the driven rollers are determined directly. For these rollers own position encoders are therefore not required for detecting the rotational position. The other rollers - so usually the support rollers, in exceptional cases exceptionally the work rolls - may have position sensor for detecting the rotational position. Alternatively, the rotational positions can be determined from the rotational positions of the driven rollers in conjunction with the rolling condition.

In some cases, it may be sufficient to determine a respective eccentricity component for the support rollers on the one hand and the work rolls on the other hand and to determine the compensation value on the basis of the two eccentricity components. This simplified procedure may be sufficient, in particular, when the diameters of the support rollers are equal to one another and the diameters of the work rollers are equal to one another.

• dass die Drehstellungen der Stützwalzen des Walzgerüsts unabhängig voneinander ermittelt oder erfasst werden und dass die Drehstellungen der Arbeitswalzen des Walzgerüsts unabhängig voneinander ermittelt oder erfasst werden,
• dass die ersten Größen Größen umfassen, welche die durch die obere Stützwalze hervorgerufene Exzentrizität in Abhängigkeit von der Drehstellung der oberen Stützwalze charakterisieren, und Größen umfassen, welche die durch die untere Stützwalze hervorgerufene Exzentrizität in Abhängigkeit von der Drehstellung der unteren Stützwalze charakterisieren,
• dass die zweiten Größen Größen umfassen, welche die durch die obere Arbeitswalze hervorgerufene Exzentrizität in Abhängigkeit von der Drehstellung der oberen Arbeitswalze charakterisieren, und Größen umfassen, welche die durch die untere Arbeitswalze hervorgerufene Exzentrizität in Abhängigkeit von der Drehstellung der unteren Arbeitswalze charakterisieren, und
• dass die Steuereinrichtung den Kompensationswert in Abhängigkeit von der jeweiligen Drehstellung sowohl der oberen und unteren Arbeitswalze als auch der oberen und unteren Stützwalze ermittelt.

In practice, however, the work rolls generally have slightly different diameters with each other. The same applies to the support rollers with each other. Preferably, the operating method is therefore designed in such a way that

• that the rotational positions of the support rollers of the roll stand are determined or detected independently of each other and that the rotational positions of the work rolls of the roll stand are determined or detected independently of each other,
• the first sizes comprise sizes characterizing the eccentricity caused by the upper back-up roll in dependence on the rotational position of the upper back-up roll and sizes which characterize the eccentricity caused by the lower back-up roll in dependence on the rotational position of the lower back-up roll;
• that the second sizes include sizes characterizing the eccentricity caused by the upper work roll depending on the rotational position of the upper work roll and sizes which characterize the eccentricity caused by the lower work roll depending on the rotational position of the lower work roll, and
• the control device determines the compensation value as a function of the respective rotational position of both the upper and lower work rolls and the upper and lower support rolls.

In this case, the compensation value has four components of eccentricity, the sum of which is equal to the compensation value, namely one eccentricity component each for the upper back-up roll, the lower back-up roll, the upper work roll and the lower work roll.

In a further preferred embodiment of the present invention takes place in normal operation during rolling breaks, during which no flat rolling is rolled, a rotation of the rolls of the rolling mill counter to the direction of rotation during rolling of the last rolled flat rolled stock. As a result, in particular in the event that not all rotational positions are detected, but some rotational positions are derived from the recorded orders, errors can be minimized, which otherwise would be due to the accumulation of a deviation would add up the rotational position over several revolutions of the rollers. In principle, however, this procedure is also possible if the rotational positions of all rollers are detected.

In a further preferred alternative embodiment is for rollers, the rotational positions are not detected, but whose rotational positions from the rotational positions of those rollers whose rotational positions are detected, are determined, each passing a reference rotational position detected and fed to the control device. By this configuration, the accumulation of a deviation of the rotational position over several revolutions of the rollers can be avoided, since with each passing of the respective reference rotational position by the respective roller a new synchronization is made possible.

In a further preferred embodiment of the present invention, during rolling breaks during which no flat rolled product is rolled, the upper and / or lower set of rolls are rotated such that when rolling the next flat rolled material a cost function is minimized, in which one by the sum of Eccentricities of the work rolls and the backup rolls formed total eccentricity, the first time derivative of the total eccentricity and / or the second time derivative of the total eccentricity enter. As a rule, only one of these three variables will enter the cost function. However, it is also possible that several of these variables are included in the cost function. As a rule, the minimization of the cost function occurs in normal operation. However, if the properties of the flat rolled stock to be rolled next are already known, it can also take place at the end of the calibration operation.

In the event that only the total eccentricity is included in the cost function, the total eccentricity to be compensated can be minimized. In an analogous manner, in the case that in the cost function only the first time derivative the total eccentricity is received, the speed at which the roll gap must be adjusted, are minimized. In an analogous manner, in the event that only the second time derivative of the total eccentricity enters into the cost function, the acceleration with which the roll gap must be adjusted can be minimized.

In many cases, the procedure according to the invention already leads to excellent results. In some cases, however, it may happen that a residual eccentricity still occurs despite the correction of the set nip value by the determined compensation value. In order to compensate for such a residual eccentricity, it is preferably provided that the control device detects during the rolling of the flat rolling stock a signal which is characteristic of the residual eccentricity. In this case, the control device can track the first and second variables based on the residual eccentricity.

The object is further achieved by a computer program having the features of claim 11. According to the invention, a computer program of the aforementioned type is configured in that the processing of the computer program by the control device causes the control device to operate the rolling stand in accordance with an operating method according to the invention.

The object is further achieved by a control device with the features of claim 12. According to the invention, the control device is designed such that it operates the roll stand according to an operating method according to the invention.

The object is further achieved by a rolling mill with the features of claim 13. According to the invention, a roll stand of the type mentioned above is configured in that the roll stand is controlled by a control device according to the invention.

FIG 1

eine perspektivische Ansicht eines Walzgerüsts,

FIG 2

eine Seitenansicht des Walzgerüsts von FIG 1,

FIG 3

ein Ablaufdiagramm,

FIG 4

zwei Arbeitswalzen und zwei Stützwalzen,

FIG 5

einen zeitlichen Verlauf eines Exzentrizitätssignals,

FIG 6

zugehörige Wege auf Walzenumfängen,

FIG 7

zwei zeitliche Verläufe von Exzentrizitätssignalen,

FIG 8

zugehörige Wege auf Walzenumfängen,

FIG 9

eine Walze und deren Änderung des Radius,

FIG 10

ein Ablaufdiagramm,

FIG 11

eine gemessene und eine zugehörige, modellierte Exzentrizität im Vergleich,

FIG 12

zugehörige Wege auf Walzenumfängen und

FIG 13

ein Ablaufdiagramm.

The above-described characteristics, features and advantages of this invention, as well as the manner in which they are achieved, will become clearer and more clearly understood in connection with the following description of the embodiments, which will be described in more detail in conjunction with the drawings. Here are shown in a schematic representation:

FIG. 1

a perspective view of a rolling stand,

FIG. 2

a side view of the rolling mill of FIG. 1 .

FIG. 3

a flow chart,

FIG. 4

two work rolls and two back-up rolls,

FIG. 5

a temporal course of an eccentricity signal,

FIG. 6

associated paths on roll circumferences,

FIG. 7

two time courses of eccentricity signals,

FIG. 8

associated paths on roll circumferences,

FIG. 9

a roller and its change of radius,

FIG. 10

a flow chart,

FIG. 11

a measured and an associated, modeled eccentricity in comparison,

FIG. 12

associated ways on roll circumferences and

FIG. 13

a flowchart.

According to the 1 and 2 For example, a rolling stand has an upper roll set U and a lower set L of rolls. The upper roller set U has an upper work roll 1U and an upper backup roll 2U. The lower roll set L has a lower work roll 1L and a lower backup roll 2L. By means of the rolling stand, a flat rolling stock 3 is rolled from metal. The flat rolling stock 3 may in particular be a heavy plate or a metal strip. The metal from which the flat rolled material 3 is made may be steel in particular. Alternatively, it may be aluminum, copper, brass or another metal.

The rolling stand is controlled by a control device 4. The control device 4 is designed such that it Runs mill according to an operating method, which will be explained in more detail below.

As a rule, the control device 4 is designed as a programmable control device 4. In this case, the corresponding design of the control device 4, so that it operates the rolling stand according to the operating method, effected by a computer program 5, with which the control device 4 is programmed. The computer program 5 comprises machine code 6, which can be processed directly by the control device 4. In this case, the execution of the machine code 6 by the control device 4 causes the control device 4 to operate the rolling mill in accordance with the corresponding operating method.

The rolling stand is operated by the control device 4 at least temporarily in a normal operation. In particular, the rolling of the flat rolling stock 3 takes place in normal operation. Often, the rolling mill is still operated by the control device 4 temporarily also in a calibration. In calibration operation no flat rolling stock is rolled by means of the roll stand 3. It is assumed below that the rolling stand is alternatively operated by the control device 4 in normal operation or in calibration operation.

The control device 4 therefore checks according to FIG. 3 first, in a step S1, whether the rolling stand is operated in normal operation. If the rolling mill is operated in normal operation, the control device 4 checks in step S2, whether currently a rolling stock 3 is rolled. If a rolling stock 3 is currently being rolled, the control device 4 proceeds to steps S3 to S7.

In step S3, a set roll gap s * is set. In a step S4, the control device 4 accepts a rotational position φUB, φUW, φLB, φLW of at least one roll 1U, 1L, 2U, 2L of the roll stand. In step S5, the controller 4 detects one of the rotational positions φUB, φUW, φLB, φLW of at least one roller 1U, 1L, 2U, 2L of the roll stand dependent compensation value ε. The determination is made on the basis of variables RUB, RUW, RLW, RLB, φ1UB, φ2UW, φ1LB, φ2LW, for a total eccentricity of the rolls 1U, 1L, 2U, 2L of the roll stand as a function of the rotational position φUB, φUW, φLB, φLW of at least a roll 1U, 1L, 2U, 2L of the roll stand are characteristic. The quantities RUB, RLB, φ1UB, φ1LB are first quantities which are characteristic of eccentricity of the rolling mill support rolls 2U, 2L as a function of a rotational position φUB, φUW, φLB, φLW of at least one roll 1U, 1L, 2U, 2L of the rolling stand. Analogously, the quantities RUW, RLW, φ2UW, φ2LW are second quantities which are characteristic of an eccentricity of the work rolls 1U, 1L as a function of a rotational position φUB, φUW, φLB, φLW of at least one roll 1U, 1L, 2U, 2L of the roll stand , The meaning of the first quantities RUB, RLB, φ1UB, φ1LB and the second quantities RUW, RLW, φ2UW, φ2LW will become apparent hereinafter.

In step S6, the control device 4 corrects the set nip value s * by the compensation value ε determined in step S4. In step S7, the control device 4 sets a rolling gap s of the roll stand according to the corrected set roll gap value. As a result, the flat rolling stock 3 is rolled from an initial thickness to a final thickness by means of the rolling stand in accordance with the corrected set nip value.

From step S7, the controller returns to step S1. The sequence of steps S1 to S7 is therefore carried out continuously during the rolling of the flat rolling stock 3 by the control device 4.

Although the control device 4 operates the rolling mill in normal operation, but currently no flat rolled material is rolled, the control device 4 proceeds from step S2 to a step S8. In step S8, other measures can be taken, which will be explained later.

If the control device 4 does not operate the rolling stand in normal operation, the rolling stand is in calibration operation. In this case, the controller proceeds to steps S9 to S14. In the calibration mode, the first and second quantities RUB, RUW, RLW, RLB, φ1UB, φ2UW, φ1LB, φ2LW are determined.

In step S9, a defined initial rotational position of the upper roller set U and a defined initial rotational position of the lower roller set L of the rolling stand are set. For example, the two initial rotational positions can be set such that in FIG. 4 shown (only mentally existing) points of the upper work roll 1U and the upper support roller 2U are directly opposite each other and in an analogous manner in FIG. 4 shown points (only mentally existing) of the lower work roll 1L and the lower support roller 2L are directly opposite each other. For this purpose, for example, the rolling stand can be ascended so that the upper work roll 1U and the lower work roll 1L do not touch each other. Thereafter, the two sets of rollers U, L are rotated independently of one another in their respective initial rotational position.

In order to be able to rotate the two sets of rollers U, L independently of one another into their respective initial rotational position, the rollers 1U, 2U of the upper roller set U are lifted off the rollers 1L, 2L of the lower roller set L. For rotating the sets of rolls U, L as such, for example, as shown in FIG FIG. 1 independent drives 7U, 7L for the two sets of rollers U, L be present. Alternatively, a common drive may be present, for example permanently connected to the lower set of rollers L, but with the upper set of rollers U via a releasable coupling. In this case, first, the upper roller set U is transferred to its initial rotational position, then the clutch is released, and it is the lower set of rollers L transferred to its initial position. Then the clutch is closed again.

After the two sets of rolls U, L have been rotated to their respective initial rotational position, the control device 4 controls the rolling stand in step S10 in such a way that the roll gap s is closed. The closing of the roll gap s takes place without the flat rolling stock being in the roll gap s. With the closing of the roll gap s, the upper work roll 1U thus rests on the lower work roll 1L.

Then, the control device 4 controls the rolling stand in step S11 such that the rolls 1U, 1L, 2U, 2L roll against each other. This state - ie the rolling of the rollers 1U, 1L, 2U, 2L together - is maintained for a relatively long length L0. The length L0 is hereinafter referred to as the detection length L0. The detection length L0 is based on the respective initial rotational position of the roller sets U, L. It is particularly dimensioned such that all rollers 1U, 1L, 2U, 2L perform several complete revolutions.

During the rolling of the rollers 1U, 1L, 2U, 2L, the control device 4 detects in step S11 at the same time over the detection length L0 a course of a signal F, s, which is characteristic of a change in the roll gap s. The signal F, s is of course dependent on the rotational position φUB, φUW, φLB, φLW of the at least one roller 1U, 1L, 2U, 2L. For example, the control device 4, the roll stand in the course of the step S11 maintain a roll gap controlled at a constant setting of the roll gap s and detect the associated rolling force F as a characteristic signal s, F. Similarly, the control device 4, conversely, the rolling stand in the context of step S11 roller force controlled with a constant rolling force F operate and detect the resulting rolling gap s as a characteristic signal s, F. In both cases, the detected signal s, F directly reflects the total eccentricity ε. FIG. 5 shows - purely by way of example - the change in the resulting roll gap s in the case of a rolling force control over a detection length L0 of 30 m and a diameter of the work rolls 1U, 1L of about 1.00 m and a diameter of the back-up rolls 2U, 2L at a diameter of about 1.65 m. FIG. 6 shows purely by way of example the corresponding revolutions of the work rolls 1U, 1L and the support rollers 2U, 2L.

In some cases, it may be sufficient to perform the procedure of steps S9 to S11 only for a single pair of initial rotational positions. In this case, the controller 4 proceeds directly to step S14. Otherwise, the control device 4 first proceeds to step S12. In step S12, the control device 4 checks whether it has already carried out the procedure of steps S9 to S11 for all required pairs of initial rotational positions. Only when this is the case, the controller 4 moves to step S14.

If this is not the case, the control device 4 proceeds from step S12 to step S13. In step S13, the controller 4 selects the next pair of initial rotational positions. From step S13, the controller then returns to step S9.

The number of other pairs of initial rotational positions and the associated positions as such may be determined as needed. If necessary, the initial rotational position of the lower roller set L may be unchanged while the upper roller set U is rotated by a predetermined angle of the upper work roll 1U or the upper backup roll 2U, respectively. The reverse procedure is also possible. It is also possible that both sets of rollers U, L are rotated.

In particular, in the case of only a single further pair of initial rotational positions, the predetermined angle may, for example, as in FIG. 4 shown by dashed lines, with a half turn of the upper support roller 2U correspond. In this case, as shown in FIG FIG. 7 in addition, another course of the signal s, F. FIG. 8 shows the associated rotational speeds of the work rolls 1U, 1L and the backup rolls 2U, 2L.

In step S14, the control device 4 uses the detected curves to determine the first and second variables RUB, RUW, RLW, RLB, φ1UB, φ2UW, φ1LB, φ2LW. The basics of this investigation are explained in more detail below.

r0 bezeichnet hierbei den mittleren (idealen) Radius der Walze 8. δri bezeichnet den Anteil der i-ten Störung. ϕi bezeichnet eine Phasenlage der i-ten Störung.Ideally, a roller 8 should be perfectly round, so have no eccentricity. In practice, however, this is not the case. FIG. 9 shows - greatly exaggerated - a variation of a radius r of the roller 8 as a function of the rotational position φ of the roller 8 relative to a reference position. Mathematically, the radius r can be written as a function of the rotational position φ as $$r\left(\phi \right)=\mathrm{<figure-callout\; id="0"\; label="r"\; filenames="imgf0003.png,imgf0004.png"\; state="\{\{state\}\}">r</figure-callout>}0+{\displaystyle \underset{i=1}{\overset{\infty }{\Sigma }}}\mathit{\delta ri}\cdot \sin \left(\mathit{Iø}-\mathit{.phi..sub.i}\right)$$

Here, r0 denotes the mean (ideal) radius of the roller 8. Δr denotes the component of the i-th perturbation. φ i denotes a phase position of the i-th perturbation.

Hierbei sind

• RUB die Exzentrizitätsamplitude der oberen Stützwalze 2U,
• RUW die Exzentrizitätsamplitude der oberen Arbeitswalze 1U,
• RLB die Exzentrizitätsamplitude der unteren Stützwalze 2L,
• RLW die Exzentrizitätsamplitude der unteren Arbeitswalze 1U,
• ϕ1UB die Phasenlage der ersten Störung der Exzentrizität der oberen Stützwalze 2U,
• ϕ2UW die Phasenlage der zweiten Störung der Exzentrizität der oberen Arbeitswalze 1U,
• ϕ1LB die Phasenlage der ersten Störung der Exzentrizität der unteren Stützwalze 2L,
• ϕ2LW die Phasenlage der zweiten Störung der Exzentrizität der unteren Arbeitswalze 1U,
• ϕUB die Drehstellung der oberen Stützwalze 2U,
• ϕUW die Drehstellung der oberen Arbeitswalze 1U,
• ϕLB die Drehstellung der unteren Stützwalze 2L und
• ϕLW die Drehstellung der unteren Arbeitswalze 1U.

For the backup rollers 2U, 2L all disturbances are relevant, since only the radius is effective for the nip s. For the work rolls 1U, 1L, however, only the even disturbances are relevant, since for the work rolls 1U, 1L for the nip s the diameter is effective. Further, considering only the disturbance at the lowest effective frequency for all the rolls 1U, 1L, 2U, 2L - ie the first disturbance for the back-up rolls 2U, 2L and the second disturbance for the work rolls 1U, 1L - the resulting eccentricity ε can be determined Write as $$\epsilon =\mathit{RUB}\cdot \sin \left(\mathit{\phi UB}-\mathrm{<figure-callout\; id="1"\; label="\phi "\; filenames="imgf0007.png"\; state="\{\{state\}\}">\phi </figure-callout>}1\mathit{UB}\right)+\mathit{RLB}\cdot \sin \left(\mathit{\phi LB}-\mathrm{<figure-callout\; id="1"\; label="\phi "\; filenames="imgf0007.png"\; state="\{\{state\}\}">\phi </figure-callout>}1\mathit{LB}\right)+\mathit{<figure-callout\; id="2"\; label="RUW\; sin"\; filenames="imgf0004.png,imgf0005.png"\; state="\{\{state\}\}">RUW\; </figure-callout>}\sin \left(2\mathit{\phi UW}-\mathrm{<figure-callout\; id="2"\; label="\phi "\; filenames="imgf0004.png,imgf0005.png"\; state="\{\{state\}\}">\phi </figure-callout>}2\mathit{UW}\right)+\mathit{RLW}\cdot \mathrm{<figure-callout\; id="2"\; label="sin"\; filenames="imgf0004.png,imgf0005.png"\; state="\{\{state\}\}">sin</figure-callout>}\left(2\mathit{\phi LW}-\mathrm{<figure-callout\; id="2"\; label="\phi "\; filenames="imgf0004.png,imgf0005.png"\; state="\{\{state\}\}">\phi </figure-callout>}2\mathit{LW}\right)$$

Here are

• RUB the eccentricity amplitude of the upper backup roll 2U,
• RUW is the eccentricity amplitude of the upper work roll 1U,
• RLB the eccentricity amplitude of the lower back-up roll 2L,
• RLW is the eccentricity amplitude of the lower work roll 1U,
• φ1UB is the phase angle of the first eccentricity disturbance of the upper back-up roller 2U,
• φ2UW is the phase angle of the second disturbance of the eccentricity of the upper work roll 1U,
• φ1LB the phase angle of the first disturbance of the eccentricity of the lower back-up roll 2L,
• φ2LW is the phase position of the second disturbance of the eccentricity of the lower work roll 1U,
• φUB the rotational position of the upper backup roller 2U,
• φ UW the rotational position of the upper work roll 1U,
• φLB the rotational position of the lower support roller 2L and
• φLW is the rotational position of the lower work roll 1U.

In Equation 2, eight quantities are unknown, namely the four eccentricity amplitudes RUB, RUW, RLW, RLB and the four phase positions φ1UB, φ2UW, φ1LB, φ2LW.

zu finden, wobei ε die für bestimmte Drehstellungen ϕUB, ϕUW, ϕLB, ϕLW gemessene Exzentrizität und ε' die für die gleichen Drehstellungen ϕUB, ϕUW, ϕLB, ϕLW gemäß Gleichung 2 errechnete Exzentrizität ist. 1 ist der auf dem Umfang der Walzen 1U, 1L, 2U, 2L zurückgelegte Weg. Derartige Optimierungen sind Fachleuten geläufig. Die Ermittlung der Drehstellungen ϕUB, ϕUW, ϕLB, ϕLW ist ohne weiteres möglich, da die (mittleren) Radien der Walzen 1U, 1L, 2U, 2L bekannt sind, weiterhin die Anfangsdrehstellungen (für 1 = 0) bekannt sind und schließlich die Abrollbedingung gilt, das heißt, dass die Walzen 1U, 1L, 2U, 2L beim Abrollen gleiche Wege zurücklegen.To determine these eight variables RUB, RUW, RLW, RLB, φ1UB, φ2UW, φ1LB, φ2LW, an optimization problem can now be set up by means of which the deviation of a norm is minimized. So you try the minimum of $${\displaystyle {\int }_{\mathrm{<figure-callout\; id="0"\; label="O\; L"\; filenames="imgf0003.png,imgf0004.png"\; state="\{\{state\}\}">O\; </figure-callout>}}^L}\Vert \epsilon \left(\mathit{\phi UB},\mathit{\phi UW},\mathit{\phi LW},\mathit{\phi LB}\right)-\epsilon \text{'}\left(\mathit{\phi UB},\mathit{\phi UW},\mathit{\phi LW},\mathit{\phi LB}\right)\Vert dl$$

where ε is the eccentricity measured for certain rotational positions φUB, φUW, φLB, φLW and ε 'is the eccentricity calculated for the same rotational positions φUB, φUW, φLB, φLW according to Equation 2. 1 is the distance traveled on the circumference of the rollers 1U, 1L, 2U, 2L. Such optimizations are familiar to those skilled in the art. The determination of the rotational positions φUB, φUW, φLB, φLW is readily possible, since the (average) radii of the rollers 1U, 1L, 2U, 2L are known, the Initial rotation positions (for 1 = 0) are known and finally the rolling condition applies, that is, the rollers 1U, 1L, 2U, 2L cover the same paths when unrolling.

In some cases, it may be sufficient to detect the rotational position φUB, φUW, φLB, φLW of only a single roller 1U, 1L, 2U, 2L and the rotational positions φUB, φUW, φLB, φLW of the other rollers 1U, 1L, 2U, 2L from the detected rotational position φUB, φUW, φLB, φLW in conjunction with the known radii or diameters of the rollers 1U, 1L, 2U, 2L deduce. However, this becomes too inaccurate, especially over longer distances, due to slippage and due to variations in radii due to eccentricities.

Preferably, therefore, as shown in FIG FIG. 1 by means of corresponding rotary position sensor 9U, 9L the rotational positions φUB, φUW, φLB, φLW detected both the support rollers 2U, 2L and the work rolls 1U, 1L of the rolling mill. The detected rotational positions φUB, φUW, φLB, φLW are supplied to the control device 4 and received by the control device 4. With respect to a pair of similar rollers 1U, 1L, 2U, 2L - usually the back-up rollers 2U, 2L - this requires an additional pair of rotary position sensors 9U, 9L. The other pair of similar rolls 1U, 1L, 2U, 2L - usually the work rolls 1U, 1L -, however, is driven by means of the rolling stand drives 7U, 7L. The rolling mill drives 7U, 7L generally have internal rotary encoder on. Their signals can be used in this case to determine the rotational positions φUB, φUW, φLB, φLW of the driven rollers 1U, 1L, 2U, 2L.

Alternatively, it may be sufficient to detect only the rotational position φUB, φUW, φLB, φLW of one of the rollers 1U, 1L, 2U, 2L of the corresponding roller set U, L per roller set U, L. In this case, only these rotational positions φUB, φUW, φLB, φLW are accepted by the control device 4. The rotational position φUB, φLB, φUW, φLW of the respective other roller 2U, 2L, 1U, 1L of the corresponding roller set U, L becomes in this case determined by the control device 4 on the basis of the rotational position φUB, φUW, φLB, φLW that roller 1U, 1L, 2U, 2L of the corresponding set of rollers U, L, the rotational position φUB, φUW, φLB, φLW is detected. This procedure is taken in this case both in normal operation and in calibration mode.

If all rotary positions φUB, φUW, φLB, φLW are detected directly by means of corresponding rotary position encoders 9U, 9L, all rotary positions φUB, φUW, φLB, φLW are directly and immediately available at any time. On the other hand, if only the rotational positions .phi.UW, .phi.LW of the work rolls 1L, 1U are detected and the rotational positions .phi.UB, .phi.LB of the backup rolls 2U, 2L are derived from the rotational positions .phi.UW, .phi.LW of the work rolls 1U, 1L, there is a risk of overflowing Distances (corresponding to many complete revolutions of the back-up rolls 2U, 2L) will make the rotational positions φUB, φLB of the back-up rolls 2U, 2L too inaccurate. To solve this problem, two alternative embodiments are possible, but in principle can be combined with each other.

On the one hand, it is possible that, during rolling pauses, the rolls 1U, 1L, 2U, 2L of the roll stand are rotated counter to the direction of rotation in which the rolls 1U, 1L, 2U, 2L are rotated during the rolling of the flat rolled rolled stock 3. The rollers 1U, 1L, 2U, 2L are therefore turned back. The turning back is a possible embodiment of the step S8 of FIG. 3 , Accordingly, the rolling mill is operated at this time in normal operation. The turning back is thus carried out as part of a normal rolling break between the rolling of two flat rolling stock 3. It is not a calibration operation in which the first and second quantities RUB, RUW, RLW, RLB, φ1UB, φ2UW, φ1LB, φ2LW are determined. By this measure it is achieved that while errors can accumulate during the rolling of a single flat rolling stock 3, but then again takes place a reduction of the accumulated error.

Alternatively, it is possible that the support rollers 2U, 2L reference signal generator 10U, 10L are assigned. Although the reference signal transmitters 10U, 10L do not detect the rotational position φUB, φLB of the support rollers 2U, 2L over the entire angular range of 360 °. However, they each output a signal (for example, a pulse) when the rotational position φUB, φLB of the corresponding back-up roller 2U, 2L corresponds to a predetermined reference rotational position. By means of the reference signal transmitter 10U, 10L, the passing of the reference rotational position is thereby detected during the continuous rotation of the support rollers 2U, 2L. The corresponding signals are of course supplied to the control device 4. This can therefore - both in normal operation and in calibration - after each complete revolution of the corresponding support roller 2U, 2L make a new synchronization of the rotational movement of the corresponding support roller 2U, 2L relative to the rotational movement of the work roll 1U, 1L of the corresponding set of rolls U, L.

Of course, the reverse procedure is also possible, that is, that the rotational positions φUB, φLB of the back-up rolls 2U, 2L are detected, the rotational positions φUW, φLW of the work rolls 1U, 1L are derived from the rotational positions φUB, φLB of the back-up rolls 2U, 2L and for the work rolls 1U, 1L each passing a reference rotational position is detected.

Above, a procedure has been explained in which (both in normal operation and in calibration), the rotational positions φUB, φLB the support rollers 2U, 2L are determined or detected independently and also the rotational positions φUW, φLW of the work rolls 1U, 1L independently determined or detected become. Thus, all four rotational positions φUB, φUW, φLB, φLW are explicitly detected or determined. In this case, the total eccentricity ε is the sum of the partial eccentricities of the rolls 1U, 1L, 2U, 2L. For each roller 1U, 1L, 2U, 2L, the control device 4 thus determines, depending on the rotational position φUB, φUW, φLB, φLW, of the respective roller 1U, 1L, 2U, 2L the associated one of the part of the roller 1U, 1L, 2U, 2L caused partial eccentricity and adds the Teilxzentrizitäten to the total eccentricity ε. In normal operation, the control device 4 thus determines the compensation value ε as a function of the respective rotational position φUB, φUW, φLB, φLW of both the upper and lower work rolls 1U, 1L and the upper and lower support rolls 2U, 2L.

In order to be able to determine the four partial eccentricities mentioned above, the control device 4 must also be aware of the corresponding characteristic variables RUB, RUW, RLW, RLB, φ1UB, φ2UW, φ1LB, φ2LW. As part of the calibration operation, the control device 4 thus determines the sizes RUB, φUB for the upper support roller 2U which are characteristic of their part eccentricity. In an analogous manner, the calibration of the lower support roll 2L, the upper work roll 1U and the lower work roll 1L also determines the two variables RUW, RLW, RLB, φ2UW, φ1LB which are characteristic of the part eccentricity of the respective roll 2L, 1U, 1L. φ2LW.

The radii or diameter of the support rollers 2L, 2U are generally equal to each other. Likewise, the radii or diameter of the work rolls 1U, 1L among each other usually the same size. If it can be ensured that between two calibrations only a sufficiently small slip occurs between the rolls 1U, 2U of the upper roll set U with respect to the rolls 1U, 1L of the lower roll set L, the part eccentricities caused by the support rolls 2U, 2L can be combined and can also summarized by the work rolls 1U, 1L Teilxzentrizitäten be summarized. Also in this case, the total eccentricity results as the sum of the part eccentricities of the back-up rolls 2U, 2L and the work rolls 1U, 1L. However, the sum in this case has only two addends, namely one for the part eccentricity caused by the back-up rolls 2U, 2L and for the part eccentricity caused by the work rolls 1U, 1L. The Control device 4 determines in this case in normal operation in dependence on the rotational position φUW, φLW one of the work rolls 1U, 1L a part eccentricity for the work rolls 1U, 1L and depending on the rotational position φUB, φLB one of the support rollers 2U, 2L a part eccentricity for the support rollers 2U, 2L. Furthermore, in this case, it adds the two partial eccentricities to the total eccentricity ε. Also in this case, the control device 4 determines the compensation value ε in normal operation as a function of the rotational position φUB, φUW, φLB, φLW of both the work rolls 1U, 1L and the support rolls 2U, 2L. As part of the calibration operation, the control device 4 determines in this case for the two support rollers 2U, 2L uniform variables that are characteristic of the Teilxzentrizität, for example, a Exzentrizitätsamplitude and a phase angle. Likewise, the control device 4 determines in this case in the calibration operation for the two work rolls 1U, 1L uniform variables that are characteristic of the part eccentricity, for example, a Exzentrizitätsamplitude and a phase angle.

Furthermore, during rolling breaks as shown in FIG FIG. 10 Steps S21 to S23 be present. Steps S21 to S23 are one possible embodiment of step S8 of FIG FIG. 1 ,

und minimiert das Integral dadurch, dass sie Drehstellungen ϕUB, ϕUW, ϕLB, ϕLW der Walzen 1U, 1L, 2U, 2L variiert, zu denen mit dem Walzen des nächsten flachen Walzguts 3 begonnen wird. Die gewalzte Länge L1 ist - bezogen auf die Mantelflächen der Walzen 1U, 1L, 2U, 2L - diejenige Länge, über welche die Walzen 1U, 1L, 2U, 2L dieses flache Walzgut 3 walzen. Im Schritt S23 stellt die Steuereinrichtung 4 sodann die Drehstellungen ϕUB, ϕUW, ϕLB, ϕLW der Walzen 1U, 1L, 2U, 2L entsprechend ein. Die Steuereinrichtung 4 dreht also den oberen und/oder den unteren Walzensatz U, L derart, dass die Kostenfunktion K beim Walzen des nächsten flachen Walzguts 3 minimiert wird.According to FIG. 10 determines the control device 4 in step S21 a cost function K. In the cost function K can - weighted with respective weighting factors α0 to α2 - for example, the total eccentricity ε, the first time derivative of the total eccentricity and / or the second time derivative of the total eccentricity received. It is possible that all three weighting factors α0 to α2 are different from zero. Alternatively, it is possible that only two of the weighting factors α0 to α2 are different from zero. However, at least one of the three weighting factors α0 to α2 must be different from 0. The weighting factors α0 to α2 may be fixed to the control device 4 or from be specified to a user as part of a parameterization. In this case, the control device 4 further determines in step S22 a minimum of the cost function K over a rolled length L1. So it forms the integral $${\displaystyle {\int }_{\mathrm{<figure-callout\; id="1"\; label="O\; L"\; filenames="imgf0007.png"\; state="\{\{state\}\}">O\; </figure-callout>}}^L}\Vert K\Vert dl$$

and minimizes the integral by varying rotational positions φUB, φUW, φLB, φLW of the rollers 1U, 1L, 2U, 2L to which rolling of the next flat rolled material 3 is started. The rolled length L1 is - based on the lateral surfaces of the rollers 1U, 1L, 2U, 2L - that length over which the rollers 1U, 1L, 2U, 2L roll this flat rolling stock 3. In step S23, the controller 4 then adjusts the rotational positions φUB, φUW, φLB, φLW of the rollers 1U, 1L, 2U, 2L accordingly. The control device 4 thus rotates the upper and / or lower roller set U, L in such a way that the cost function K during rolling of the next flat rolling stock 3 is minimized.

It is possible that in the context of step S23, the rolling stand is closed. In this case, the two sets of rollers U, L can only be rotated together. Alternatively, the rolling stand can be opened. In this case, the two sets of rollers U, L can be rotated independently.

The procedure according to the invention leads to excellent results. FIG. 11 shows purely by way of example a comparison between a measured (M) eccentricity ε and an associated, modeled (C) eccentricity ε, ie an eccentricity ε, which is determined on the basis of the eccentricity amplitudes RUB, RUW, RLW, RLB and phase positions φ1UB, φ2UW, φ1LB, φ2LW was, with the Exzentrizitätsamplituden RUB, RUW, RLW, RLB and phase angles φ1UB, φ2UW, φ1LB, φ2LW were determined based on the measured course of the eccentricity ε. FIG. 12 shows the associated course of the revolutions of the rollers 1U, 1L, 2U, 2L.

Ideally, the eccentricities of the rollers 1U, 1L, 2U, 2L are completely compensated by the addition of the compensation signal ε. Due to thermal effects, wear, etc., however, it may happen that, despite the correction of the set nip value s * by the determined compensation value ε, only an incomplete compensation takes place, ie that a residual eccentricity εr remains. It is therefore possible that the control device 4 as shown in FIG FIG. 13 During the rolling of the flat rolled stock 3, in a step S31, a signal F, Z characteristic of the residual eccentricity εr is detected. This signal F, Z may be, for example, the rolling force F or a train Z prevailing in front of or behind the rolling stand in the flat rolling stock 3. A thickness of the flat rolled stock 3 measured on the outlet side of the roll stand can also be used as a signal.

In this case, on the one hand, the control device 4 in a step S32 currently - that is, during the rolling of the flat rolled material 3 - compensate for the residual eccentricity εr. In this case, the control device 4 thus corrects the set nip value s * not only by the compensation value ε, but additionally by the residual eccentricity εr. Further, in this case, the controller 4 may track the first and second quantities RUB, RUW, RLW, RLB, φ1UB, φ2UW, φ1LB, φ2LW in a step S33. It is even possible that the control device 4 completely determines the first and second variables RUB, RLB, φ1UB, φ1LB, RUW, RLW, φ2UW, φ2LW on the basis of the residual eccentricity ε _r , that the amplitudes RUB, RLB, RUW, RLW of the individual eccentricities so initially have the value 0. The phase positions φ1UB, φ1LB, φ2UW, φ2LW are irrelevant in this case at first.

In the context of the explanation of the present invention were above as first and second sizes RUB, RUW, RLW, RLB, φ1UB, φ2UW, φ1LB, φ2LW eccentricity amplitudes RUB, RUW, RLW, RLB and phase positions φ1UB, φ2UW, φ1LB, φ2LW. Alternatively, the eccentricities of the rolls 1U, 1L, 2U, 2L could alternatively be described by amplitudes AUB, BUB, ALB, BLB, AUW, BUW, ALW, BLW of corresponding sine and cosine functions. Instead of equation 2, therefore, the following equation 5 could also be assumed. $$\epsilon =\mathit{AUB}\cdot \sin \mathit{\phi UB}+\mathit{BOY}\cdot \cos \mathit{\phi UB}+\mathit{ALB}\sin \mathit{\phi LB}+\mathit{BLB}\cos \mathit{\phi LB}+\mathit{<figure-callout\; id="2"\; label="AUW\; sin"\; filenames="imgf0004.png,imgf0005.png"\; state="\{\{state\}\}">AUW\; </figure-callout>}\sin \mathrm{}2\mathit{\phi UW}+\mathit{<figure-callout\; id="2"\; label="UW\; cos"\; filenames="imgf0004.png,imgf0005.png"\; state="\{\{state\}\}">UW\; </figure-callout>}\cos 2\mathit{\phi UW}+\mathit{<figure-callout\; id="2"\; label="ALW\; sin"\; filenames="imgf0004.png,imgf0005.png"\; state="\{\{state\}\}">ALW\; </figure-callout>}\sin 2\mathit{\phi LW}+\mathit{<figure-callout\; id="2"\; label="BLW\; cos"\; filenames="imgf0004.png,imgf0005.png"\; state="\{\{state\}\}">BLW\; </figure-callout>}\cos 2\mathit{\phi LW}$$

In summary, the present invention thus relates to the following facts:

A rolling stand for rolling a flat rolled metal 3 has an upper roll set U and a lower roll set L with corresponding work rolls 1U, 1L and back-up rolls 2U, 2L. In a normal operation, the flat rolling stock 3 is rolled. In this case, a control device 4 continuously determines on the basis of first and second quantities RUB, RLB, φ1UB, φ1LB, RUW, RLW, φ2UW, φ2LW, for eccentricity of the back-up rolls 2U, 2L and the work rolls 1U, 1L of the roll stand as a function of a rotational position φUB , φUW, φLB, φLW of at least one roll 1U, 1L, 2U, 2L of the roll stand are characteristic of the rotation position φUB, φUW, φLB, φLW dependent compensation value ε. The control device 4 corrects a roll gap setpoint s * for the roll stand by the compensation value ε and applies the roll stand accordingly.

The present invention has many advantages. In particular, all Walzenexzentrizitäten can be determined and compensated. This is true regardless of whether the eccentricities are caused by work rolls 1U, 1L or back-up rolls 2U, 2L. Furthermore, the roll eccentricities can be determined faster and more accurately. Furthermore, the roll eccentricities can be determined even if the Roll stand in addition to the work rolls 1U, 1L and the support rollers 2U, 2L further rollers, in particular between the work rolls 1U, 1L and the support rollers 2U, 2L arranged intermediate rolls.

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

LIST OF REFERENCE NUMBERS

1L, 1U

strippers

2L, 2U

backup rolls

3

flat rolling stock

4

control device

5

computer program

6

machine code

7U, 7L

Rolling mill drives

8th

roller

9U, 9L

Rotary encoder

10U, 10L

Reference signal generator

C

modeled eccentricity

K

cost function

L, U

roll sets

L0

recording length

L1

rolled length

M

measured eccentricity

r

radius

r0

average radius

RUB, RUW, RLW, RLB

Exzentrizitätsamplituden

s

nip

s *

Should nip

S1 to S33

steps

α0 to α 2

Weighting factors

δri

disorder

ε

compensation value

ε, ε ', ε r

eccentricities

.phi..sub.i

phasing

φUB, φUW, φLB, φLW

rotational positions

φ1UB, φ2UW, φ1LB, φ2LW

Exzentrizitätsphasen

Claims (13)

Operating method for a rolling stand for rolling a flat rolled stock (3) of metal, - wherein the roll stand comprises an upper set of rolls (U) and a lower set of rolls (L), wherein the upper set of rolls (U) has at least one upper work roll (1U) and one upper support roll (2U) and the lower set of rolls (L) has at least one lower work roll (1L) and one lower support roll (2L), wherein the rolling mill is operated at least temporarily in a normal operation, - Wherein the roll stand is operated during the rolling of the flat rolled stock (3) in normal operation, - Wherein during the rolling of the flat rolled stock (3) a control device (4) for the roll stand continuously by means of first variables (RUB, RLB, φ1UB, φ1LB), which are used for an eccentricity of the supporting rolls (2U, 2L) of the roll stand as a function of a rotational position (φUB, φUW, φLB, φLW) of at least one roll (1U, 1L, 2U, 2L) of the roll stand and second quantities (RUW, RLW, φ2UW, φ2LW) corresponding to eccentricity of the work rolls (1U, 1L) of the roll stand as a function of a rotational position (φUB, φUW, φLB, φLW) of at least one Roller (1U, 1L, 2U, 2L) of the roll stand are characteristic, one of the rotational position (φUB, φUW, φLB, φLW) of the at least one roller (1U, 1L, 2U, 2L) of the roll stand dependent compensation value (ε) determined - a roll gap setpoint (s *) for the rolling stand corrected by the calculated compensation value (ε) and setting a roll gap (s) of the roll stand according to the corrected roll gap setpoint, so that the flat rolling stock (3) is rolled by means of the rolling stand in accordance with the corrected set nip value. Operating method according to claim 1,
characterized,
that the rolling stand operated temporarily in a calibration mode is rolled in which by means of the roll stand no flat rolling stock (3) and that the control device (4) in the calibration mode for a number of defined initial rotational positions of both the upper set of rolls (U) and the lower set of rolls (L), controls the roll stand so that the upper work roll (1U) rests on the lower work roll (1L) and the rolls (1U, 1L, 2U, 2L), - During the rolling of the rollers (1U, 1L, 2U, 2L) to each other via a starting from the respective initial rotational position respective detection length (L0) one of the rotational position (φUB, φUW, φLB, φLW) of the at least one roller (1U, 1L , 2U, 2L) depending on a characteristic of a change in the roll gap (s) characteristic signal (s, F) is detected and - Based on the detected curves, the first and second quantities (RUB, RUW, RLW, RLB, φ1UB, φ2UW, φ1LB, φ2LW) determined. Operating method according to claim 2,
characterized,
that the number of initial rotational positions is greater than 1. Operating method according to claim 1,
characterized,
that the first and second variables (RUB, RLB, φ1UB, φ1LB, RUW, RLW, φ2UW, φ2LW) of the control device (4) from a higher-level control device or by an operator can be specified. Operating method according to one of the above claims, characterized - That the rotational positions (φUB, φUW, φLB, φLW) of both the back-up rollers (2U, 2L) and the work rolls (1U, 1L) of the rolling mill and detected by the control device (4) are received or that the rotational position (φUB, φUW , φLB, φLW) of only the work rolls (1U, 1L) or only the back-up rolls (2U, 2L) of the rolling stand are detected and received by the control device (4) and the rotational positions (φUB, φUW, φLB, φLW) of those rollers (1U, 1L, 2U, 2L) whose rotational positions (φUB, φUW, φLB, φLW) are not detected by the control device (4) from the rotational positions (φUB, φUW, φLB, φLW) of those rollers (1U, 1L, 2U, 2L) whose rotational positions (φUB, φUW, φLB, φLW) are detected, - that the first quantities (RUB, RLB, φ1UB, φ1LB) characterize the eccentricity of the back-up rolls (2U, 2L) in dependence on the rotational position (φUB, φLB) of the back-up rolls (2U, 2L), - that the second quantities (RUW, RLW, φ2UW, φ2LW) characterize the eccentricity of the work rolls (1U, 1L) in dependence on the rotational position (φUW, φLW) of the work rolls (1U, 1L) and - That the control device (4) determines the compensation value (ε) in dependence on the rotational position (φUB, φUW, φLB, φLW) of both the work rolls (1U, 1L) and the support rollers (2U, 2L). Operating method according to claim 5,
characterized, - That the rotational positions (φUB, φLB) of the support rollers (2U, 2L) of the rolling mill are determined or detected independently and that the rotational positions (φUW, φLW) of the work rolls (1U, 1L) of the rolling mill are determined or detected independently of each other, - that the first quantities (RUB, RLB, φ1UB, φ1LB) sizes (RUB (φ1UB) include that characterize the (by the upper support roller 2U) induced eccentricity in accordance with the rotational position (φUB) of the upper support roller (2U), and sizes (RLB, φ1LB) characterizing the eccentricity caused by the lower back-up roll (2L) in accordance with the rotational position (φLB) of the lower back-up roll (2L), - that the second variables (RUW, RLW, φ2UW, φ2LW) sizes (RUW, φ2UW) include which characterize by the upper work roll (1U) induced eccentricity in accordance with the rotational position (φUW) of the upper working roll (1U), and magnitudes (RLW, φ2LW) characterizing the eccentricity caused by the lower work roll (1L) in accordance with the rotational position (φLW) of the lower work roll (1L), and that the control means (4) sets the compensation value (ε) in Depending on the respective rotational position (φUB, φUW, φLB, φLW) of both the upper and lower work rolls (1U, 1L) and the upper and lower support roller (2U, 2L) determined. Operating method according to one of claims 1 to 6, characterized
that in normal operation during rolling breaks, during which no flat rolled stock (3) is rolled, a rotation of the rollers (1U, 1L, 2U, 2L) of the roll stand against the rotational direction during rolling of the last-rolled flat rolled stock (3). Operating method according to one of claims 1 to 6, characterized
that for rolls (1U, 1L, 2U, 2L) whose rotational positions (φUB, φUW, φLB, φLW) are not detected, but whose rotational positions (φUB, φUW, φLB, φLW) from the rotational positions (φUB, φUW, φLB, φLW) of those rollers (1U, 1L, 2U, 2L) whose rotational positions (φUB, φUW, φLB, φLW) are detected are detected, respectively, the passing of a reference rotational position and the control device (4) is supplied. Operating method according to one of the above claims, characterized
that during rolling breaks, during which no flat rolled stock (3) is rolled, the upper and / or lower roll set (U, L) are rotated such that a cost function (K) is minimized during rolling of the next flat rolled stock (3), in which a total eccentricity (ε) formed by the sum of the eccentricities of the work rolls (1U, 1L) and the support rolls (2U, 2L), the first time derivative (ε̇ of the total eccentricity (ε) and / or the second time derivative (ε̈) the total eccentricity (ε) go. Operating method according to one of the above claims, characterized
that the control device (4) during rolling of the flat rolled stock (3) detects a signal (F, Z), which is for a residual eccentricity (.epsilon..sub.R) characteristic, despite the correction of the roll gap set value (s *) (to the determined compensation value ε ), and the first and second quantities (RUB, RUW, RLW, RLB, φ1UB, φ2UW, φ1LB, φ2LW) are traced based on the residual eccentricity (εr). Computer program for a control device (4) of a roll stand for rolling a flat rolled stock (3) of metal, the computer program comprising machine code (6) which can be processed directly by the control device (4), wherein the processing of the machine code (6) by the Control device (4) causes the control device (4) to operate the roll stand according to an operating method according to one of the preceding claims. Control device for a roll stand for rolling a flat rolled stock (3) made of metal, wherein the control device is designed such that it operates the roll stand according to an operating method according to one of claims 1 to 10. Rolling stand for rolling a flat rolled stock (3) of metal, wherein the rolling stand is controlled by a control device (4) according to claim 12.

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