Shape control device for cluster rolling mill

Abstract

When the shape deviation average value for an edge area is greater than the shape deviation average value for a quarter area, and the shape deviation average value for the quarter area is less than a lower limit value, or when the shape deviation average value for the edge area is less than the shape deviation average value for the quarter area, and the shape deviation average value for the quarter area is greater than an upper limit value, a processing circuit of this shape control device: changes a monitoring flag; changes the weight of control on the edge area by a first actuator to zero; uses the shape deviation, the changed weight, and a shape effect coefficient to calculate an operation amount of the first actuator at which the shape deviation of the quarter area is minimized; if the operation amount of the first actuator is determined to be in a direction in which the shape of the quarter area is made worse, replaces the operation amount of the first actuator with zero, and uses the shape deviation, the weight coefficient, and the shape effect coefficient to calculate an operation amount of a second actuator at which the shape deviation of the edge area is minimized.

Description

Shape control device for cluster rolling mill

[0001] This disclosure relates to a shape control device for controlling the shape of a rolled material, and more particularly to a shape control device for a cluster rolling mill, such as a Sendimear rolling mill.

[0002] Cluster rolling mills (hereinafter also referred to as "rolling mills"), such as Sendimir rolling mills, employ a structure in which multiple rolls are stacked to suppress deformation of the work rolls in the width direction. This type of Sendimir rolling mill comprises a pair of upper and lower work rolls, a first intermediate roll, a second intermediate roll, and a divided backup roll. A tapered portion is formed at the axial end of the first intermediate roll. The first intermediate roll is connected to a first actuator and is configured to be moved in the axial direction. The divided backup roll is divided into multiple divided rolls in the width direction. Each divided roll is connected to a second actuator and is configured to change the angle of the eccentric sleeve of each divided roll.

[0003] In general shape control, a shape meter with multiple measurement zones divided in the width direction of the rolled material is placed at the exit of the rolling mill. The difference between the actual shape and the target shape in each measurement zone is defined as the shape deviation, and the amount of manipulation for each actuator that minimizes the shape deviation is calculated using a weighted least squares method. For example, consider a Sendimier rolling mill where the number of the first measurement zone of the shape meter covered by the rolled material is S, the number of the last measurement zone is E, and there are a total of J cylinders that operate the actuators. In this case, the amount of manipulation ΔL for each actuator that minimizes the evaluation function θ expressed by equation (1) below is ΔL. ｊ (mm) is calculated.

[0004] Here, in equation (1) above, i is the measurement zone number of the shape meter (-), j is the actuator number, ε is the shape deviation (I-unit), ∂βi / ∂Lj is the shape influence coefficient (I-unit / mm), and α is the weighting coefficient (-).

[0005] In the shape control disclosed in Patent Document 1 below, the convergence time is shortened by changing the initially set weighting coefficient when the shape deviation does not decrease during acceleration / deceleration or constant-speed rolling.

[0006] In the shape control disclosed in Non-Patent Document 1 below, when calculating the amount of operation of the first actuator that moves the first intermediate roll, the difference between the shape deviation of the measurement zone assigned to the edge area and the shape deviation of the measurement zone assigned to the quarter area is monitored, and the weight coefficient of the edge area is changed according to that difference.

[0007] Japanese Patent Publication No. 7-144209

[0008] Toshihiro Nii et al., “Advanced Thickness and Flatness Control System for Sendzimir Mill”, IRON & STEEL TECHNOLOGY, pp.78-83, published June 2020

[0009] However, if the weight coefficient of a measurement zone in which the shape of the rolled material is to be primarily corrected is set to a large value (changed), the shape of that measurement zone may improve, but the shape of other measurement zones may deteriorate. For example, when changing the weight coefficient of the edge area, if the changed weight coefficient is not sufficiently small, the balance between the shape deviation of the edge area and the shape deviation of the quarter area will be disrupted, resulting in an increase in the shape deviation of the quarter area. Also, if the weight coefficient of the edge area is changed to 0, and the setting of the shape influence coefficient for the movement of the first intermediate roll in the measurement zone designated in the quarter area is not appropriate, the amount of operation of the actuator that moves the first intermediate roll may be calculated in a direction that increases the shape deviation of the quarter area. Furthermore, if shape deviations of different polarities are mixed in multiple measurement zones assigned to the quarter area, there is a risk that the first intermediate roll will be moved in a direction that increases the shape deviation of the quarter area.

[0010] This disclosure was made to solve the problems described above. The purpose of this disclosure is to provide a shape control device for a cluster rolling mill that can improve the shape of a quarter area without degrading the shape of the edge area, even when a shape defect occurs in the quarter area.

[0011] The first aspect of this disclosure relates to a shape control device for a cluster rolling mill. The cluster rolling mill to which the shape control device is applied includes an intermediate roll having a tapered portion at its axial end and a divided backup roll. A shape meter is positioned at the exit side of the cluster rolling mill, having a plurality of measurement zones divided in the width direction of the rolled material, and measuring the shape of the rolled material in each measurement zone. The shape control device includes a processing circuit that calculates the amount of operation of a first actuator that moves the intermediate roll axially and the amount of operation of a second actuator that drives the divided backup roll, and outputs the calculated amounts of operation to a position control device that controls each actuator.The processing circuit acquires the target shape of the rolled material set by the setting device, the parameter of the shape influence coefficient representing the degree of influence of each actuator on the shape of the rolled material, and the control weight coefficient for each measurement zone; manages the number of measurement zones of the shape meter to be assigned to the edge area and quarter area of ​​the rolled material; calculates the shape deviation, which is the difference between the actual shape of the rolled material measured in each measurement zone assigned to the edge area and quarter area and the target shape; compares the magnitude relationship between the average shape deviation of the edge area and the average shape deviation of the quarter area; changes the monitoring flag from its initial value when the average shape deviation of the edge area is greater than the average shape deviation of the quarter area and the average shape deviation of the quarter area is below a predetermined lower limit, or when the average shape deviation of the edge area is less than the average shape deviation of the quarter area and the average shape deviation of the quarter area is above a predetermined upper limit; and when the monitoring flag has been changed from its initial value In response to this, the system is configured to perform the following actions: change the weight coefficient for control of the edge area by the first actuator to 0; calculate the shape influence coefficient for each measurement zone using the shape influence coefficient parameter;, in response to the change in the monitoring flag from its initial value, calculate the amount of operation of the first actuator that minimizes the shape deviation of the quarter area using the shape deviation, the changed weight coefficient, and the shape influence coefficient;, in response to the change in the monitoring flag from its initial value, determine from the state of the monitoring flag and the polarity of the amount of operation of the first actuator whether or not the amount of operation of the first actuator is in a direction that worsens the shape of the quarter area;, in response to the determination that the amount of operation of the first actuator is in a direction that worsens the shape of the quarter area, replace the amount of operation of the first actuator with 0; and, in response to the change in the monitoring flag from its initial value, calculate the amount of operation of the second actuator that minimizes the shape deviation of the edge area using the shape deviation, the weight coefficient, and the shape influence coefficient.

[0012] The second aspect, in addition to the first aspect, has the following further characteristics: The setting device is configured to set the number of measurement zones of the shape meter to be assigned to the edge area and quarter area of ​​the rolled material. Managing the number of measurement zones of the shape meter includes obtaining the number of measurement zones set by the setting device.

[0013] The third perspective, in addition to the first perspective, has the following further characteristics: The processing circuit is configured to calculate the manipulated amount of the first actuator and the manipulated amount of the second actuator separately using different evaluation functions.

[0014] The fourth viewpoint has the following additional features in addition to any one of the first to third viewpoints: The processing circuit is configured to set the polarity of the shape influence coefficient of the first actuator that modifies the shape of the quarter area as first polarity, monitor whether the shape influence coefficient of each measurement zone in the calculated quarter area has first or second polarity, and, upon finding that there is a target measurement zone in the quarter area whose shape influence coefficient has second polarity, calculate the average value of the shape influence coefficients of the other measurement zones that have first polarity, and replace the shape influence coefficient of the target measurement zone that has second polarity with the average value.

[0015] Here, there are two things whose polarity changes depending on the conditions. The first is the polarity of the actual shape. The second is the polarity of the shape deviation. The first, the polarity of the measured shape, depends on whether a positive value is defined as stretched (loose) or as taut (tight). When the rolled material is a steel such as stainless steel or magnetic steel, it is common to define a positive value as stretched (loose), whereas when the rolled material is aluminum, it may be defined as taut (tight). The second, the polarity of the shape deviation, depends on whether the target shape is subtracted from the actual shape or the actual shape is subtracted from the target shape. The polarity of the shape influence coefficient in the quarter area is determined by the polarity of the measured shape. For example, if a positive value is defined as stretched, the polarity of the shape influence coefficient in the quarter area will be negative. This means that if the first actuator is operated by, for example, 1 mm, the quarter area will become taut. Based on the above, if we define a positive value as elongation, the first polarity of the shape influence coefficient in the quarter area becomes negative. If the shape deviation is calculated by subtracting the target shape from the actual shape, the shape deviation will be positive due to elongation. If the shape deviation is calculated by subtracting the actual shape from the target shape, the shape deviation will be negative due to elongation. On the other hand, if we define a negative value as elongation, the first polarity of the shape influence coefficient in the quarter area becomes positive. If the shape deviation is calculated by subtracting the target shape from the actual shape, the shape deviation will be negative due to elongation. If the shape deviation is calculated by subtracting the actual shape from the target shape, the shape deviation will be positive due to elongation.

[0016] The fifth viewpoint has the following additional features in addition to any one of the first to third viewpoints: The processing circuit is configured to set the polarity of the shape influence coefficient of the first actuator that modifies the shape of the quarter area as first polarity, monitor whether the shape influence coefficient of each measurement zone of the calculated quarter area has first or second polarity, and, upon finding that there is a target measurement zone in the quarter area whose shape influence coefficient has second polarity, calculate an extrapolated value from the shape influence coefficients of the other zones in the quarter area that have first polarity, and replace the shape influence coefficient of the target measurement zone that has second polarity with the extrapolated value.

[0017] The sixth viewpoint, in addition to the fifth viewpoint, has the following further characteristics: The processing circuit is configured to, upon receiving that the extrapolated value has a second polarity, further replace the shape influence coefficient of the target measurement zone that has a second polarity with the value closest to zero among the shape influence coefficients used for extrapolation.

[0018] The seventh viewpoint, in addition to the fifth viewpoint, has the following further features: The processing circuit is configured to, upon receiving that the extrapolated value is greater than the largest value on the first polarity side among the shape influence coefficients used for extrapolation, further replace the shape influence coefficient with the value closest to zero among the shape influence coefficients used for extrapolation for the target measurement zone.

[0019] According to the first aspect of this disclosure, the amount of operation of the first actuator that minimizes the shape deviation of the quarter area is calculated with the weighting coefficient of the control of the edge area by the first actuator changed to 0. Moreover, it is prevented that the first actuator is operated in a direction that worsens the shape of the quarter area. Furthermore, the amount of operation of the second actuator that minimizes the shape deviation of the edge area is calculated. Therefore, even if a shape defect occurs in the quarter area, the shape of the quarter area can be improved without worsening the shape of the edge area.

[0020] From a second perspective, the number of measurement zones of the shape meter to be assigned to the edge area and quarter area of ​​the rolled material can be managed by using the settings of the setting device.

[0021] From a third perspective, by using different evaluation functions, it is possible to accurately calculate the amount of manipulation of the first actuator that minimizes the shape deviation of the quarter area and the amount of manipulation of the second actuator that minimizes the shape deviation of the edge area.

[0022] From the fourth to seventh perspectives, even when shape influence coefficients with different polarities are mixed in the quarter area, it is possible to prevent the intermediate roll from moving in a direction that increases the shape deviation of the quarter area.

[0023] This figure shows an example configuration of a cold rolling line equipped with a Sendimear rolling mill to which the rolled material shape control device according to Embodiment 1 is applied. This is a side view of the Sendimear rolling mill as seen from the Y direction. This is a view of the first intermediate roll shown in Figure 2 as seen from the X direction. This is a perspective view showing an example configuration of the divided backup rolls shown in Figure 2. This is a schematic diagram showing the measurement zones of the shape meter designated in the edge area and quarter area. This is a figure of the area management table. This is a figure for explaining the shape influence coefficient obtained by multiplying the weight coefficient before the change of the edge area by the weight coefficient changed by the weight change unit. This is a figure showing the phenomenon prevented by the operation amount monitoring unit. This figure shows an example configuration of a cold rolling line equipped with a Sendimear rolling mill to which the rolled material shape control device according to Embodiment 2 is applied. This is a figure for explaining the shape influence coefficient before correction of the quarter area and the shape influence coefficient after correction by the shape influence coefficient monitoring unit. This is a figure showing an example hardware configuration of the rolled material shape control device.

[0024] Hereinafter, embodiments of this disclosure will be described with reference to the drawings, using as an example the case where it is applied to a reversible Sendimear rolling mill installed in a cold rolling line. In addition, elements common to each figure are denoted by the same reference numerals, and redundant explanations are omitted.

[0025] Embodiment 1. Figure 1 shows an example of the configuration of a cold rolling line equipped with a Sendimear rolling mill to which the rolled material shape control device (hereinafter also referred to as the "shape control device") according to Embodiment 1 is applied. The cold rolling line (hereinafter also referred to as the "rolling line") 2 is equipped with a Sendimear rolling mill (hereinafter also referred to as the "rolling mill") 21 as a cluster rolling mill for rolling the rolled material. The rolled material 20 is made of a high-strength material such as stainless steel or magnetic steel. The rolling line 2 is further equipped with a pair of tension reels 22 and 23 and two shape gauges 24 and 25.

[0026] The rolled material 20, unwound from the tension reel 22, is transported to the right in Figure 1 and rolled by the rolling mill 21. The shape of the rolled material 20 (hereinafter also referred to as the "actual shape") is measured by a shape meter 25 installed on the exit side of the rolling mill, and then it is wound onto the tension reel 23. Rolling is temporarily stopped with several wraps of rolled material remaining on the tension reel 22. Then, the rolled material 20 unwound from the tension reel 23 is transported in the reverse direction and rolled by the Sendimear rolling mill 21. The actual shape of the rolled material 20 is measured by a shape meter 24, and then it is wound onto the tension reel 22. Rolling is repeated while changing the transport direction until the rolled material 20 reaches the desired thickness.

[0027] In the following explanation, the transport direction will be described as the X direction, the vertical direction as the Z direction, and the width direction of the rolled material 20 perpendicular to the X and Z directions as the Y direction. Furthermore, regarding the polarity of the actual shape (also referred to as the "measured shape"), a positive actual shape measured by shape meters 24 and 25 will be defined as a loose shape, and a negative actual shape will be defined as a tight shape. A measurement zone in which the actual shape is positive indicates that the rolled material is stretched more than in other measurement zones, and a measurement zone in which the actual shape is negative indicates that the rolled material is tauter than in other measurement zones.

[0028] Figure 2 is a side view of the Sendimear rolling mill 21 as seen from the Y direction. Figure 3 is a view of the first intermediate roll shown in Figure 2 as seen from the X direction. Figure 4 is a perspective view showing an example of the configuration of the divided backup rolls shown in Figure 2.

[0029] The Sendimear rolling mill 21 has one stand. The Sendimear rolling mill 21 is a cluster rolling mill with 20 rolls arranged in a row. The Sendimear rolling mill 21 includes a pair of small-diameter upper and lower work rolls 211 that grip and roll the rolled material 20, two pairs of upper and lower first intermediate rolls 212 that support the work rolls 211, three pairs of upper and lower second intermediate rolls 213 that support the first intermediate rolls 212, and four pairs of upper and lower divided backup rolls 214 that support the second intermediate rolls 213.

[0030] A Sendzimir mill 21 includes, as mechanisms for controlling the shape of a rolled material, a first intermediate roll (IMR) shifting mechanism and an As-U-Roll (As-U) mechanism. That is, the Sendzimir mill 21 includes shape control actuators 215 and 216. The first intermediate roll 212 has a tapered portion 212a formed at an end on either side in the Y direction (axial direction). A first actuator 215 is provided on the drive side of the first intermediate roll 212 in the Y direction. The first actuator 215 is connected to a position control device 4 described later. The position control device 4 operates the first actuator 215 by the manipulated variable calculated by the shape control device 1, and can move the first intermediate roll 212 in the Y direction. Note that the first actuator 215 may also be provided on the work side of the first intermediate roll 212.

[0031] The split backup roll 214 has bearing rolls 214a that are a plurality of (five in the example shown in FIG. 4) split rolls split in the Y direction (axial direction). Each bearing roll 214a is provided with a second actuator 216 for imparting roll crown, respectively. Similarly to the first actuator 215, the second actuator 216 is also connected to the position control device 4 described later. The position control device 4 can operate the second actuator 216 by the manipulated variable calculated by the shape control device 1.

[0032] Shapeometers 24 and 25 have a plurality of measurement zones divided in the Y direction, and measure the shape (flatness) of the rolled material 20 in each measurement zone. The actual shape of the rolled material 20 measured in each measurement zone of the shapeometers 24 and 25 is transmitted to a shape deviation calculation unit 10 of the shape control device 1 described later. Since publicly known devices can be used as the shapeometers 24 and 25, further detailed description thereof is omitted.

[0033] The shape control device 1 controls the shape (flatness) of the rolled material 20 by controlling the respective actuators 215 and 216. Hereinafter, shape control of the rolled material 20 will be described with an example where the rolled material 20 unwound from a tension reel 22 is rolled by the Sendzimir mill 21 and wound up by a tension reel 23.

[0034] The shape control device 1 comprises a shape deviation calculation unit 10, an edge / quota monitoring unit 11, an area management unit 12 having an area management table 13, a weight change unit 14, a shape influence coefficient calculation unit 15, an operation amount calculation unit 16, and an operation amount monitoring unit 17.

[0035] The shape deviation calculation unit 10 acquires the actual shape of each measurement zone measured by the shape meter 25 at the exit of the rolling mill. The shape deviation calculation unit 10 acquires (receives) the target shape of the rolled material set by the setting device 3 (also called the "setting computer") which is higher level than the shape control device 1. In addition to the target shape, the setting device 3 sets parameters for calculating the shape influence coefficient and weight coefficients (hereinafter also called "weights") for each measurement zone and transmits them to the shape control device 1. As a result, the target shape, parameters, and weight coefficients are set in the shape control device 1 before rolling starts.

[0036] The shape deviation calculation unit 10 calculates the shape deviation for each measurement zone, which is the difference between the actual shape and the target shape for each measurement zone. In the following, the shape deviation is defined as the value obtained by subtracting the actual shape from the target shape. In this case, if the actual shape is looser than the target shape, the shape deviation will be negative. On the other hand, if the actual shape is tighter than the target shape, the shape deviation will be positive.

[0037] The edge / quota monitoring unit 11 acquires the number of zones designated as edge areas and quota areas in the area management table 13 managed by the area management unit 12. Figure 5 is a schematic diagram showing the measurement zones of the shape meters designated as edge areas and quota areas. Shape meters 24 and 25 have multiple measurement zones divided in the width direction. In the example shown in Figure 5, numbers from No. 1 to No. I are assigned to each measurement zone from the work side toward the drive side. Of the multiple measurement zones of each shape meter 24 and 25, the measurement zones covered by the rolled material 20 are valid. In the example shown in Figure 5, measurement zones No. 3 to No. I-2 are valid, and the actual shapes measured in the valid measurement zones are transmitted to the shape deviation calculation unit 10. In the following, among the valid measurement zones, a predetermined number of measurement zones inward in the Y direction from the measurement zones at both ends in the Y direction are designated as edge areas, and a predetermined number of measurement zones further inward in the Y direction from each edge area are designated as quota areas. In the example shown in Figure 5, three measurement zones No. Numbers 3 through 5 are designated, and three measurement zones, No. 6 through 8, are designated as quarter areas.

[0038] The area management unit 12 has an area management table 13 for managing edge areas and quarter areas. Figure 6 shows the area management table 13. The area management table 13 manages the number of measurement zones in the edge area and the number of measurement zones in the quarter area for each plate width division. Generally, the parameters used in rolling control are managed by dividing the thickness and width of the rolled material 20 into multiple ranges and managing each division. In this embodiment, the case in which the division of the area management table 13 is limited to the width of the rolled material is described as an example, but the division may also be the width and thickness of the rolled material. The number of divisions is determined by the range of material types and product sizes produced in the rolling line 2 and the control target, and in Figure 6, the number of plate width divisions is N. It is preferable to set initial values ​​in advance for the number of measurement zones in the edge area and quarter area, and adjust the number of measurement zones while observing the shape control status.

[0039] The edge / quarter monitoring unit 11 acquires the number of measurement zones in the edge area and quarter area according to the width of the rolled material 20. Using the acquired number of zones, the edge / quarter monitoring unit 11 calculates the average value of the shape deviation of the edge area and quarter area using the following formulas (2) to (5). Formulas (2) and (3) below are formulas for calculating the average value of the shape deviation of the edge area and quarter area on the work side, respectively. Formulas (4) and (5) below are formulas for calculating the average value of the shape deviation of the edge area and quarter area on the drive side, respectively.

[0040] Here, in equations (2) to (5) above, S is the number of the first zone (-) among the measurement zones covered by the rolled material of the shape meter. E is the number of the last zone (-) among the measurement zones covered by the rolled material of the shape meter. ε is the shape deviation (I-unit). ne is the number of zones set as edge areas (-). nq is the number of zones set as quarter areas (-).

[0041] The edge / quarter monitoring unit 11 compares and monitors the relationship between the average value of the shape deviation of the edge area and the average value of the shape deviation of the quarter area, calculated using equations (2) to (5) above. The comparison and monitoring of the average value of the shape deviation between the edge area and the quarter area is performed separately for the work side and the drive side. Equation (6) below is used for monitoring the work side. Equation (7) below is used for monitoring the drive side.

[0042] Here, the left-hand side of equations (6) and (7) above is the average value of the shape deviation of the quarter area, and the right-hand side is the average value of the shape deviation of the edge area. If the relationship between equations (6) and (7) above is satisfied, that is, if the average value of the shape deviation of the edge area is greater than the average value of the shape deviation of the quarter area, then we determine whether the relationship between equations (8) and (9) below is satisfied. That is, the average value of the shape deviation of the quarter area is the lower limit ε ＬＬ Determine whether it is less than (I-unit). Lower limit ε ＬＬ(I-unit) is a set value for determining whether the actual shape of a quarter area is an allowable loose shape. According to the following formulas (8) and (9), when the actual shape of the quarter area is looser than that of the edge area, it is determined whether the actual shape exceeds the allowable loose shape.

[0043] When the relationship of the above formulas (8) and (9) is satisfied, that is, the average value of the shape deviation of the quarter area is the lower limit ε ＬＬ If it is smaller, as shown in the following formulas (10) and (11), each monitoring flag f on the work side and drive side ＷＳ , f ＤＳ is assigned the numerical value "1". Note that each monitoring flag f ＷＳ , f ＤＳ is initialized to "0" every control cycle. f ＷＳ = 1 (10) f ＤＳ = 1 (11)

[0044] When the relationship of the above formulas (6) and (7) is not satisfied, it is determined whether the relationship of the following formulas (12) and (13) is satisfied, that is, whether the average value of the shape deviation of the quarter area is the upper limit ε ＵＬ (I-unit) or not. The upper limit ε ＵＬ (I-unit) is a set value for determining whether the actual shape of a quarter area is an allowable tight shape. According to the following formulas (12) and (13), when the actual shape of the quarter area is tighter than that of the edge area, it is determined whether the actual shape exceeds the allowable tight shape.

[0045] When the average value of the shape deviation of the quarter area is the upper limit ε ＵＬ If it is larger, as shown in the following formulas (14) and (15), each monitoring flag f ＷＳ , f ＤＳ is assigned the numerical value "2". f ＷＳ = 2 (14) f ＤＳ = 2 (15)

[0046] The weight modification unit 14 controls the monitoring flag f determined by the edge / quota monitoring unit 11. ＷＳ , f ＤＳ If it is 1 or 2, that is, the monitoring flag f ＷＳ , f ＤＳ If the weight coefficient has been changed from its initial value, the weight coefficient of each measurement zone in the edge area specified by the area management unit 12 is changed to 0. Each measurement zone in the edge area whose weight coefficient has been changed to 0 is excluded from the shape control. As a result, the operation amount calculation unit 16 calculates the operation amount of the first actuator 215 ignoring the shape of the edge area. Figure 7 is a diagram illustrating the shape influence coefficient obtained by multiplying the weight coefficient before the edge area change by the weight coefficient changed by the weight change unit. Figure 7 shows the shape influence coefficient of the upper first intermediate roll shift with the weight coefficient taken into consideration. The horizontal axis of Figure 7 is the measurement zone number of the shape meter. In the example shown in Figure 7, the measurement zone numbers No. 1 to 11 from the center of the rolling mill to the work side are shown. The vertical axis of Figure 7 shows the shape influence coefficient multiplied by the weight coefficient. In the example shown in Figure 7, there is no rolled material in zones No. 1 and No. 2, and the first zone among the measurement zones covered by the rolled material of the shape meter is zone No. 3. The measurement zone covered by the rolled material depends on the width of the rolled material.

[0047] The upper part of Figure 7 shows the shape influence coefficient multiplied by the weight coefficient of the edge area before it is modified by the weight modification unit 14. In this case, when the first intermediate roll is moved 1 mm toward the work side, which is the positive direction, the shape of the edge area changes loosely, while the shape of the quarter area changes tightly. This disclosure utilizes this difference in effect on the shape of the edge area and the quarter area. The lower part of Figure 7 shows the shape influence coefficient multiplied by the weight coefficient of the edge area after it has been modified by the weight modification unit 14. As the weight coefficient of the edge area is changed to 0, the shape influence coefficient multiplied by the weight coefficient of the edge area also becomes 0. As a result, the amount of actuator operation required to correct the shape of the edge area is not calculated, and the amount of actuator operation required to correct the shape of the quarter area is calculated.

[0048] For example, if the weight coefficient of the edge area is not changed by the weight changing unit 14, or is not set to zero, even if elongation occurs in the quarter area, the upper first intermediate roll will not be manipulated in the direction of outward movement, and elongation may remain in the rolled material in the quarter area. This is because the edge area is also subject to evaluation by the least squares method, and therefore, the shape of the edge area is evaluated as deteriorating due to the outward manipulation. On the other hand, if the weight coefficient of the edge area is changed to zero, the manipulation amount is calculated using the negative shape influence coefficient of the quarter area, so the upper first intermediate roll becomes manipulated in the direction of outward movement, and the quarter elongation improves. The same applies to the drive side, which is not shown in Figure 7.

[0049] The shape influence coefficient calculation unit 15 calculates the shape influence coefficient in each measurement zone using the shape influence coefficient parameters set by the setting device 3. The shape influence coefficient is generally calculated using a model equation. For example, the shape influence coefficient of the first intermediate roll 212 is calculated using equation (16) below. The shape influence coefficient of the divided backup roll 214 is calculated using equation (17) below.

[0050] Here, in equations (16) and (17) above, j is the number (-) of actuators 215 and 216. ｉ is the position (-) of each measurement zone of the shapemeters 24 and 25 when the width of the rolled material 20 is normalized to ±1.0. B is the width of the rolled material 20 (mm). P is the rolling load (kN). h is the thickness of the rolled material 20 at the exit of the rolling mill (mm). L ＩＲｊ This is the shift position (mm) of the first intermediate roll 212. ＡＳＵｊ This is the distance (mm) from the center of the mill in the plate width direction of the operating cylinder of the divided backup roll 214. The parameters of the shape influence coefficient set by the setting device 3 are usually managed in a table divided by material type (steel type), plate thickness, plate width, etc., and appropriate parameters are set for each rolled material. Since known methods can be used for calculating the shape influence coefficient including these parameters, further detailed explanation is omitted.

[0051] The manipulated amount calculation unit 16 calculates the manipulated amounts of each actuator 215, 216 so as to minimize the evaluation function θ shown in equation (1) above, using the weight coefficient set by the setting device 3, or the changed weight coefficient if the weight of the edge area has been changed by the weight change unit 14, and the shape influence coefficient calculated by the shape influence coefficient calculation unit 15. Here, the actuator manipulated amount of the first intermediate roll and the actuator manipulated amount of the divided backup roll are calculated independently using separate evaluation functions. This makes it possible to correct the deterioration of the edge area shape by the divided backup roll even if the weight coefficient of the edge area is changed to 0 and the first intermediate roll is moved outward or inward to correct the shape of the quarter area. If the divided backup roll reaches the machine limit and can no longer correct the shape, the shape of the edge area will change to loose or tight, in which case the conditions of equations (6) and (7) above will no longer be met, and the monitoring flag will be initialized to 0. As a result, the weighting coefficient set by the setting device 3 is used as the weighting coefficient for the edge area, and the amount of operation of the first intermediate roll that suppresses shape defects in the edge area is calculated. This balances the shape of the edge area and the shape of the quarter area, preventing deterioration of the shape of one of the areas.

[0052] The operation amount monitoring unit 17 monitors the workside monitoring flag f determined by the edge / quota monitoring unit 11. ＷＳ If the value is 1, and the operating amount of the first actuator 215 that moves the upper first intermediate roll 212 calculated by the operating amount calculation unit 16 is a negative value, that is, in the direction of movement inward, the operating amount of the first actuator 215 that moves the upper first intermediate roll 212 is set to 0. Similarly, the operating amount monitoring unit 17 monitors the drive side monitoring flag f ＤＳIf the value is 1, and the operating amount of the first actuator 215 that moves the lower first intermediate roll 212, calculated by the operating amount calculation unit 16, is a negative value, the operating amount of the first actuator 215 that moves the lower first intermediate roll 212 is set to 0. This prevents the quarter area from becoming even looser when the first intermediate roll 212 moves inward.

[0053] Furthermore, the operation amount monitoring unit 17 monitors the workside monitoring flag f ＷＳ If the value is 2, and the operating amount of the first actuator 215 that moves the upper first intermediate roll 212 calculated by the operating amount calculation unit 16 is a positive value, that is, in the direction of movement outwards, the operating amount of the first actuator 215 that moves the upper first intermediate roll 212 is set to 0. Similarly, the operating amount monitoring unit 17 monitors the drive side monitoring flag f ＤＳIf the value is 2, and the operating amount of the first actuator 215 that moves the lower first intermediate roll 212, calculated by the operating amount calculation unit 16, is a positive value, then the operating amount of the first actuator 215 that moves the lower first intermediate roll 212 is set to 0. This prevents the quarter area from becoming even tighter by moving the first intermediate roll outwards when the quarter area is determined to be tight. Figure 8 shows a phenomenon that the operating amount monitoring unit 17 prevents. The horizontal axis of Figure 8 is the measurement zone number of the shape meter, showing only the work side from the center of the rolling mill. The vertical axis is the shape deviation. In Figure 8, three measurement zones No. 3 to 5 are specified in the edge area, and three measurement zones No. 6 to 8 are specified in the quarter area. In the upper part of Figure 8, the operating amount of the first actuator 215 that moves the upper first intermediate roll 212 is calculated using the weighted least squares method with the weight of the edge area set to 0 for the shape deviation in the figure, and the operating amount of the first actuator 215 is positive. The quarter area is loose, and the shape deviations of the three measurement zones No. 6 to 8 designated within the quarter area all have the same polarity. In the lower part of Figure 8, if the manipulated amount is calculated similarly for the shape deviations shown in the figure, the manipulated amount is calculated as a negative value. The shape deviations of the three measurement zones No. 6 to 8 designated within the quarter area do not all have the same polarity. When the weight of the edge area is set to 0, the purpose is to improve the loose or tight shape of the entire quarter area, and the manipulated amount monitoring unit 17 prevents unintended manipulated amounts from being used for control.

[0054] The position control device 4 controls each actuator 215, 216 based on the actuator operation amount calculated by the shape control device 1 at each control cycle (for example, 50 msec).

[0055] As described above, according to this embodiment, with the weighting coefficient for control of the edge area by the first actuator 215 changed to 0, the amount of operation of the first actuator 215 that minimizes the shape deviation of the quarter area is calculated. Moreover, it is prevented that the first actuator 215 is operated in a direction that worsens the shape of the quarter area. Furthermore, the amount of operation of the second actuator 216 that minimizes the shape deviation of the edge area is calculated. Therefore, even if a shape defect occurs in the quarter area, the shape of the quarter area can be improved without worsening the shape of the edge area. In addition, even if the divided backup roll 214 reaches the machine limit and the shape of the edge area cannot be improved, it is possible to suppress the deterioration of the shape of either the edge area or the quarter area.

[0056] Embodiment 2. Figure 9 shows an example of the configuration of a cold rolling line equipped with a Sendimear rolling mill to which the rolled material shape control device according to Embodiment 2 is applied. The shape control device 1 according to Embodiment 2 differs from that of Embodiment 1 in that it further includes a shape influence coefficient monitoring unit 18. The configuration other than the shape influence coefficient monitoring unit 18 is the same as that of Embodiment 1, so its description is omitted.

[0057] The shape influence coefficient monitoring unit 18 monitors the polarity of the shape influence coefficient in each measurement zone designated in the quarter area calculated by the shape influence coefficient calculation unit 15, when the monitoring flag determined by the edge / quarter monitoring unit 11 is 1 or 2. That is, the shape influence coefficient monitoring unit 18 monitors whether the shape influence coefficient of each measurement zone in the quarter area has a positive or negative polarity. If there is a measurement zone with a shape influence coefficient that has a positive polarity, the shape influence coefficient monitoring unit 18 corrects the shape influence coefficient of that measurement zone to have a negative polarity.

[0058] Figure 10 is a diagram illustrating the shape influence coefficient of the quarter area before correction and the shape influence coefficient after correction by the shape influence coefficient monitoring unit 18. Figure 10 shows the shape influence coefficient of the first actuator 215 that moves the upper first intermediate roll 212, taking into account the weight coefficient used in calculating the amount of operation of the first actuator 215. The horizontal axis of Figure 10 is the measurement zone number of the shape meter. In the example shown in Figure 10, measurement zone numbers No. 1 to 11 from the center of the rolling mill to the work side are shown. The vertical axis of Figure 10 shows the shape influence coefficient multiplied by the weight coefficient. The upper part of Figure 10 shows the shape influence coefficient of the quarter area before correction by the shape influence coefficient monitoring unit 18. If the monitoring flag is 1 or 2, the weight coefficient of the edge area is changed to 0, and the edge area is ignored. In the upper part of Figure 10, of the three measurement zones No. 6 to 8 designated in the quarter area, only the shape influence coefficient of measurement zone No. 6 is a positive value. 6 corresponds to the "target measurement zone" in the claim. Thus, if measurement zone No. 6, which has a positive shape influence coefficient, exists in the quarter area, that is, if positive and negative polarities are mixed in the quarter area, there is a risk that the amount of operation of the first actuator 215 will not be of the intended polarity. As a result, there is a risk that the first intermediate roll 212 will move in a direction that increases (worsens) the shape deviation of the quarter area.

[0059] Therefore, if a shape influence coefficient with positive polarity exists in measurement zone No. 6 of the quarter area, the shape influence coefficient monitoring unit 18 changes it to a shape influence coefficient with negative polarity by replacing the positive shape influence coefficient of measurement zone No. 6 with the average value of the shape influence coefficients of the other measurement zones No. 7 and 8 designated in the quarter area. The same procedure is followed for the drive side, which is not shown.

[0060] As described above, according to this embodiment, even when shape influence coefficients with different polarities are mixed in the quarter area (measurement zones No. 6 to 8), it is possible to prevent the first intermediate roll 212 from moving in a direction that increases the shape deviation of the quarter area.

[0061] There are no specific limitations on the structure of the shape control device 1, but as an example, it may be as follows. Figure 11 shows an example of the hardware configuration of the shape control device 1. The functions of the shape control device 1 can be realized by the processing circuit 100 shown in Figure 11. This processing circuit 100 may be dedicated hardware 100a. This processing circuit may include a processor 100b and a memory 100c. This processing circuit may be formed in part as dedicated hardware 100a and further include a processor 100b and a memory 100c. In the example in Figure 11, part of the processing circuit 100 is formed as dedicated hardware 100a, and the processing circuit also includes a processor 100b and a memory 100c.

[0062] At least a portion of the processing circuit may be at least one dedicated hardware 100a. In this case, the processing circuit may be, for example, a single circuit, a composite circuit, a programmed processor, a parallel programmed processor, an ASIC, an FPGA, or a combination thereof. The processing circuit may also include at least one processor 100b and at least one memory 100c. In this case, each function of the shape control device 1 is realized by software, firmware, or a combination of software and firmware. The software and firmware are written as programs and stored in the memory 100c. The processor 100b realizes the functions of each part of the shape control device 1 by reading and executing the programs stored in the memory 100c. The processor 100b is also called a CPU (Central Processing Unit), processing unit, arithmetic unit, microprocessor, microcomputer, or DSP. The memory 100c may be, for example, a non-volatile or volatile semiconductor memory such as RAM, ROM, flash memory, EPROM, or EEPROM. In this way, the processing circuit can realize each function of the shape control device 1 through hardware, software, firmware, or a combination thereof.

[0063] While embodiments of this disclosure have been described above, this disclosure is not limited to the embodiments described above and can be implemented in various modified forms without departing from the spirit of this disclosure. When the number of elements, quantities, amounts, ranges, etc., are mentioned in the embodiments described above, this invention is not limited to the number mentioned unless it is specifically stated or clearly defined in principle. Furthermore, the structures, etc., described in the embodiments described above are not necessarily essential to this invention unless they are specifically stated or clearly defined in principle.

[0064] In the above embodiment, the shape influence coefficient monitoring unit 18 described an example in which, when measurement zone No. 6 having a shape influence coefficient with positive polarity exists in the quarter area, the positive influence coefficient of measurement zone No. 6 is replaced with the average value of the negative shape influence coefficients of the other measurement zones No. 7 and 8 in the quarter area. However, the unit is not limited to this. For example, a value extrapolated from the negative shape influence coefficients of the other measurement zones may be calculated, and the unit may replace the value with the calculated extrapolated value. This allows for more accurate improvement of the shape deviation of the quarter area compared to the case where the average value is used for replacement.

[0065] Incidentally, there are cases where the extrapolated value has a positive polarity. In this case, the shape influence coefficient with positive polarity in measurement zone No. 6 should be replaced with the value closest to zero among the shape influence coefficients in measurement zones No. 7 and 8 used for extrapolation. Also, there are cases where the extrapolated value is more negative than the largest negative value among the shape influence coefficients used for extrapolation. In this case, it should be replaced with the value closest to zero among the shape influence coefficients used for extrapolation.

[0066] In the above embodiment, the number of measurement zones assigned to edge areas and quarter areas is managed by the area management table 13 of the area management unit 12, but these number of measurement zones may also be set by the setting device 3. In this case, the area management unit 12 only needs to obtain the number of measurement zones from the setting device 3 and does not need to have an area management table 13.

[0067] In the above embodiment, a Sendimear rolling mill 21 having one stand was described as an example, but this disclosure can also be applied to Sendimear rolling mills having two or more stands arranged in parallel in the X direction.

[0068] In the above embodiment, a reverse-type Sendhimir rolling mill 21 was described as an example, but this disclosure can also be applied to a Sendhimir rolling mill that rolls in one direction. In the above embodiment, the case in which the shape control device 1 is applied to a Sendhimir rolling mill 21 in a cold rolling line 2 was described as an example, but it can also be applied to a Sendhimir rolling mill in a hot rolling line.

[0069] In the above embodiment, the case where the rolled material is steel was described as an example, but the rolled material may also be a non-ferrous material such as aluminum. Furthermore, regarding the polarity of the actual shape, a positive actual shape may be defined as a tight shape, and a negative actual shape may be defined as a loose shape.

[0070] 1...Rolled material shape control device, 10...Shape deviation calculation unit, 11...Edge / Quota monitoring unit, 12...Area management unit, 13...Area management table, 14...Weight change unit, 15...Shape influence coefficient calculation unit, 16...Operation amount calculation unit, 17...Operation amount monitoring unit, 18...Shape influence coefficient monitoring unit, 2...Cold rolling line, 20...Rolled material, 21...Sendimear rolling mill, 211...Work roll, 212...First intermediate roll, 212a...Tapered section, 213...Second intermediate roll, 214...Split backup roll, 214a...Bearing roll, 215...First actuator, 216...Second actuator, 22, 23...Tension reel, 24, 25...Shape meter, 3...Setting device, 4...Position control device

Claims

1. A shape control device for a cluster rolling mill, wherein the cluster rolling mill comprises an intermediate roll having a tapered portion at its axial end and a divided backup roll, a shape meter is arranged on the exit side of the cluster rolling mill, having a plurality of measurement zones divided in the width direction of the rolled material, and measuring the shape of the rolled material in each measurement zone, the shape control device comprises a processing circuit that calculates the amount of operation of a first actuator that moves the intermediate roll in the axial direction and the amount of operation of a second actuator that drives the divided backup roll, and outputs the calculated amounts of operation to a position control device that controls each actuator, the processing circuit acquires the target shape of the rolled material set by a setting device, parameters of a shape influence coefficient representing the degree of influence of each actuator on the shape of the rolled material, and control weight coefficients for each measurement zone, manages the number of measurement zones of the shape meter to be assigned to the edge area and quarter area of ​​the rolled material, and calculates the shape deviation, which is the difference between the actual shape of the rolled material measured in each measurement zone assigned to the edge area and the quarter area and the target shape, Comparing the magnitude relationship between the average value of the shape deviation of the edge area and the average value of the shape deviation of the quarter area; changing the monitoring flag from its initial value when the average value of the shape deviation of the edge area is greater than the average value of the shape deviation of the quarter area and the average value of the shape deviation of the quarter area falls below a predetermined lower limit, or when the average value of the shape deviation of the edge area is less than the average value of the shape deviation of the quarter area and the average value of the shape deviation of the quarter area exceeds a predetermined upper limit; changing the weight coefficient for control of the edge area by the first actuator to 0 when the monitoring flag has been changed from its initial value; calculating the shape influence coefficient for each measurement zone using the parameter of the shape influence coefficient; and calculating the amount of operation of the first actuator that minimizes the shape deviation of the quarter area using the shape deviation, the changed weight coefficient, and the shape influence coefficient when the monitoring flag has been changed from its initial value.A shape control device for a cluster rolling mill, configured to perform the following actions upon receiving a change in the monitoring flag from its initial value: determine whether the amount of the first actuator is in a direction that worsens the shape of the quarter area, based on the state of the monitoring flag and the polarity of the amount of the first actuator's operation; replace the amount of the first actuator's operation with 0, upon receiving a change in the monitoring flag from its initial value; and calculate the amount of the second actuator's operation that minimizes the shape deviation of the edge area, using the shape deviation, the weighting coefficient, and the shape influence coefficient.

2. A shape control device for a cluster rolling mill according to claim 1, wherein the setting device is configured to set the number of measurement zones of the shape meter to be assigned to the edge area and quarter area of ​​the rolled material, and the shape control device for a cluster rolling mill includes managing the number of measurement zones of the shape meter by obtaining the number of measurement zones set by the setting device.

3. The shape control device for a cluster rolling mill according to claim 1, wherein the processing circuit is configured to individually calculate the amount of the first actuator and the amount of the second actuator using different evaluation functions.

4. A shape control device for a cluster rolling mill according to any one of claims 1 to 3, wherein the processing circuit is configured to further perform: setting the polarity of the shape influence coefficient of the first actuator that corrects the shape of the quarter area as the first polarity, and monitoring whether the calculated shape influence coefficient of each measurement zone in the quarter area has the first polarity or the second polarity; detecting that there is a target measurement zone in the quarter area whose shape influence coefficient has the second polarity, calculating the average value of the shape influence coefficients of the other measurement zones that have the first polarity; and replacing the shape influence coefficient of the target measurement zone that has the second polarity with the average value.

5. A shape control device for a cluster rolling mill according to any one of claims 1 to 3, wherein the processing circuit is configured to further perform: setting the polarity of the shape influence coefficient of the first actuator that corrects the shape of the quarter area as the first polarity, and monitoring whether the calculated shape influence coefficient of each measurement zone of the quarter area has the first polarity or the second polarity; detecting that there is a target measurement zone in the quarter area whose shape influence coefficient has the second polarity, calculating an extrapolated value from the shape influence coefficient of the other zones in the quarter area that has the first polarity; and replacing the shape influence coefficient of the target measurement zone that has the second polarity with the extrapolated value.

6. A shape control device for a cluster rolling mill according to claim 5, wherein the processing circuit is configured to further perform the following: upon receiving that the extrapolated value has a second polarity, replace the shape influence coefficient of the target measurement zone having a second polarity with the value closest to zero among the shape influence coefficients used for extrapolation.

7. A shape control device for a cluster rolling mill according to claim 5, wherein the processing circuit is configured to further perform the following actions when it receives that the extrapolated value is greater than the largest value on the first polarity side among the shape influence coefficients used for extrapolation, the shape influence coefficient having the second polarity of the target measurement zone is replaced with the value closest to zero among the shape influence coefficients used for extrapolation.

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