PRESETTING METHOD

Abstract

A preset value of at least one setting value in a shape control actuator included in a cold rolling mill is calculated by a presetting method. In the presetting method, an MC actual value for cold rolling performed in the past is calculated. In the presetting method, an MC target value in a rolled stock to be manufactured by the cold rolling to be performed next is calculated based on the MC actual value. In the presetting method, the setting value is selected so that a difference between an MC prediction value in the cold rolling to be performed next and the MC target value is minimized, and the selected setting value is set as the preset value.

Claims

1. A presetting method of performing cold rolling using a work roll and calculating a preset value of at least one setting value of a shape control actuator included in a cold rolling mill for manufacturing a rolled stock, the presetting method comprising: inputting, to a model, input data including an actual value of a rolling load, the setting value, and a prediction value or an actual value of a width distribution of a thermal expansion amount at the work roll in the cold rolling performed in a past to calculate an MC actual value that is a vector in which ratios of mechanical plate crowns to a width center plate thickness at one or more width positions in the rolled stock are arranged; calculating, based on the MC actual value, an MC target value MC_g that is a vector in which target values of ratios of the mechanical plate crowns to the width center plate thickness at the one or more width positions P in the rolled stock to be manufactured by the cold rolling to be performed next are arranged; and selecting the setting value in the cold rolling to be performed next so that a norm of a difference represented by Expression (1) is minimized, and setting the selected setting value as the preset value, $\begin{array}{cc}=\mathrm{MC\_g}-\mathrm{MC\_n},& \mathrm{Expression}\left(1\right)\end{array}$ where, MC_n in Expression (1) is a vector in which prediction values of ratios of the mechanical plate crowns to the width center plate thickness at the one or more width positions P are arranged, the vector being obtained by inputting, to the model, prediction input data including a prediction value of the rolling load in the cold rolling to be performed next, the setting value in the cold rolling to be performed next, and a prediction value or an actual value of a width distribution of a thermal expansion amount at the work roll immediately before the cold rolling to be performed next.

2. The presetting method according to claim 1, comprising: inputting, to the model, the input data including an actual value of a rolling load at a predetermined longitudinal position, the setting value, and a prediction value or an actual value of a width distribution of a thermal expansion amount at the work roll in the cold rolling performed immediately before to calculate the MC actual value; and setting the MC actual value as the MC target value.

3. The presetting method according to claim 1, comprising: storing, in a storage unit, the MC actual value calculated at a timing when a shape of a tip end of the rolled stock is stable and a material type of the rolled stock or a rolling condition in association with each other for each of a plurality of times of the cold rolling performed in the past to create a table; and extracting, from the table, the MC actual value associated with a material type or a rolling condition closest to the material type of the rolled stock or the rolling condition in the cold rolling to be performed next among the material types of the rolled stock or the rolling conditions included in the table, and setting the extracted MC actual value as the MC target value.

4. The presetting method according to claim 1, comprising: storing, in a storage unit, the MC actual value calculated at a timing when a shape of a tip end of the rolled stock is stable and a material type of the rolled stock or a rolling condition in association with each other for each of a plurality of times of the cold rolling performed in the past to create a table; extracting, from the table, the MC actual value associated with a material type or a rolling condition closest to the material type of the rolled stock or the rolling condition in the cold rolling to be performed next among the material types of the rolled stock or the rolling conditions included in the table, and setting the extracted MC actual value as a first MC target value; extracting, from the table, the MC actual value associated with a material type or a rolling condition closest to the material type of the rolled stock or the rolling condition in the cold rolling performed immediately before among the material types of the rolled stock or the rolling conditions included in the table, and setting the extracted MC actual value as a second MC target value; inputting, to the model, the input data including an actual value of a rolling load at a predetermined longitudinal position, the setting value, and a prediction value or an actual value of a width distribution of a thermal expansion amount at the work roll in the cold rolling performed immediately before to calculate a third MC target value that is a vector in which ratios of the mechanical plate crowns to the width center plate thickness at the one or more width positions P are arranged; and calculating the MC target value based on the first MC target value, the second MC target value, and the third MC target value.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0012] An example embodiment of the present disclosure will be described hereinafter with reference to the accompanying drawings, in which:

[0013] FIG. 1 is a block diagram illustrating a configuration of a cold rolling mill;

[0014] FIG. 2 is a flowchart illustrating a method of presetting a work roll bending force by a setting computer in a first embodiment;

[0015] FIG. 3A is a graph showing a result of simulation of a comparative example;

[0016] FIG. 3B is a graph showing a result of simulation in the first embodiment;

[0017] FIG. 4 is an explanatory diagram showing a configuration of a table;

[0018] FIG. 5 is a flowchart illustrating a method of creating and updating the table;

[0019] FIG. 6 is a flowchart illustrating a method of presetting a work roll bending force by a setting computer in a second embodiment;

[0020] FIG. 7A is a graph showing a result of simulation of a comparative example;

[0021] FIG. 7B is a graph showing a result of simulation in the second embodiment;

[0022] FIG. 8 is a flowchart illustrating a method of presetting a work roll bending force by a setting computer in a third embodiment;

[0023] FIG. 9A is a graph showing a result of simulation of a comparative example; and

[0024] FIG. 9B is a graph showing a result of simulation in the third embodiment.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

First Embodiment

1. Configuration of Cold Rolling Mill 1

[0025] A configuration of a cold rolling mill 1 will be described with reference to FIG. 1. The cold rolling mill 1 includes work rolls 3A and 3B and backup rolls 5A and 5B. The work rolls 3A and 3B are arranged in up-down directions. The backup rolls 5A and 5B sandwich the work rolls 3A and 3B in the up-down directions. The work rolls 3A and 3B are driven to rotate. A coil 7 is fed in a direction X and cold-rolled between the work rolls 3A and 3B. The cold-rolled coil 7 is referred to as a rolled stock 7A. The cold rolling mill 1 performs cold rolling using the work rolls 3A and 3B to manufacture the rolled stock 7A.

[0026] The cold rolling mill 1 includes a sensor group 11, a programmable logic controller (PLC) 13, a setting computer 15, a high-order PC 17, and a shape control actuator 19. The sensor group 11 includes a plurality of sensors. The sensor group 11 senses a rolling load, a plate thickness of the rolled stock 7A, a shape of the rolled stock 7A, a spray result, a value of the shape control actuator 19, and the like.

[0027] The rolling load is the magnitude of a load applied to the coil 7 by the work rolls 3A and 3B. The spray result is results of ON/OFF information of each spray nozzle, a spray pressure, a spray flow rate, and the like. A value sensed by the sensor group 11 is set as an actual value. The sensor group 11 transmits the actual value to the PLC 13. The PLC 13 collects the actual values during the cold rolling, and transmits the collected actual values to the setting computer 15.

[0028] The setting computer 15 includes a setting calculation unit 15A and a learning calculation unit 15B. The setting calculation unit 15A calculates control information such as various setting values including a preset value in the cold rolling mill 1 and various parameters. The learning calculation unit 15B performs learning calculation processing for improving model calculation accuracy of the setting calculation unit 15A based on result data. The setting computer 15 acquires the actual value from the PLC 13. In addition, the setting computer 15 acquires basic information including rolling conditions and the like from the high-order PC 17. The rolling conditions are information including a material of a target coil, an entry-side plate thickness, an exit-side target plate thickness, a plate width, and the like.

[0029] The setting computer 15 calculates the control information based on the actual value and the basic information. The control information includes a preset value of the shape control actuator 19 and the like. The setting computer 15 transmits the control information to the PLC 13. The PLC 13 sets a setting value of the shape control actuator 19 based on the control information. Examples of the shape control actuator 19 include a work roll bender, an intermediate roll bender, VC, and TP.

2. Basic Processing Performed by Setting Computer 15

[0030] The setting computer 15 calculates a preset value of the shape control actuator 19 based on the actual value and the basic information before starting the cold rolling. The preset value of the shape control actuator 19 includes a preset value V_p to be described later. The calculated preset value is preset in the shape control actuator 19. A presetting method of calculating the preset value V_p will be described in detail later.

[0031] The PLC 13 calculates a setting value of the shape control actuator 19 based on the actual value during the cold rolling. At this time, the PLC 13 performs feedback so that the shape of the rolled stock 7A approaches the target shape, and calculates a setting value of the shape control actuator 19. As a result, the setting value of the shape control actuator 19 is modified from the preset value to a newly calculated setting value. The previous setting value of the shape control actuator 19 is replaced with the newly calculated setting value.

3. Presetting Method

[0032] A presetting method executed by the setting computer 15 will be described with reference to FIG. 2. The presetting method is performed between cold rolling on one coil 7 and cold rolling on the next coil 7. The cold rolling performed before the presetting method is the cold rolling performed in the past. The cold rolling performed immediately before the presetting method is the cold rolling performed immediately before. The cold rolling performed immediately before is part of the cold rolling performed in the past. The cold rolling to be performed immediately after the presetting method is the cold rolling to be performed next.

[0033] In step 1 (S1) of FIG. 2, the setting computer 15 calculates an MC actual value by inputting, to a model M, input data for the cold rolling performed immediately before. The input data in the cold rolling performed immediately before includes following contents (a) to (c). [0034] (a) An actual value of a rolling load in the cold rolling performed immediately before. [0035] (b) A setting value V of a work roll bending force in the cold rolling performed immediately before. [0036] (c) A prediction value of width distribution of a thermal expansion amount at the work rolls 3A and 3B in the cold rolling performed immediately before.

[0037] The values of (a) and (b) are parts of the actual values. The setting computer 15 acquires, from the PLC 13, actual values of the rolling load, an amount of coolant supplied to the coil 7 and the work rolls 3A and 3B, a rolling speed, a plate thickness, and the like in the cold rolling performed immediately before. The setting computer 15 predicts the value of (c) based on the acquired actual values.

[0038] The values of (a) to (c) are values at a portion, at a predetermined longitudinal position, of the coil 7 that has been cold-rolled immediately before. The longitudinal position is a position of the coil 7 in a longitudinal direction. The predetermined longitudinal position is, for example, a position, of the coil 7, near a tail end.

[0039] The model M is stored in the setting computer 15 in advance, for example. When input data is input, the model M outputs the MC actual value. The model M can be updated, for example, by learning performed by the learning calculation unit 15B.

[0040] The MC actual value is a vector in which ratios of mechanical plate crowns to a width center plate thickness at one or more width positions P in the rolled stock 7A are arranged. The width position P is a position of the coil 7 in a width direction. The meaning of the mechanical plate crown at the width position P is as follows.

[0041] It is assumed that a uniform load is applied to the coil 7 in the width direction. A position of the coil 7 at the center in the width direction is defined as a center position Pc. The width position P and the center position Pc are located at the same position in the longitudinal direction. The plate thickness of the coil 7 at the center position Pc is denoted as a width center plate thickness D.sub.Pc. The plate thickness of the coil 7 at the width position P is denoted by D.sub.P. The mechanical plate crown at the width position P is a value obtained by subtracting the plate thickness D.sub.P from the width center plate thickness D.sub.Pc. A value obtained by dividing the mechanical plate crown by the width center plate thickness D.sub.Pc is a ratio of the mechanical plate crown to the width center plate thickness.

[0042] In step 2 (S2), the setting computer 15 calculates an MC target value MC_g based on the MC actual value calculated in step 1. The MC target value MC_g is a vector in which target values of ratios of mechanical plate crowns to a width center plate thickness at one or more width positions P in a rolled stock 7A manufactured by the cold rolling to be performed next are arranged. In the present embodiment, the setting computer 15 sets the MC actual value calculated in step 1 as the MC target value MC_g.

[0043] In step 3 (S3), the setting computer 15 calculates a preset value V_p of the work roll bending force. The calculation method is as follows. The setting computer 15 selects a value of (b) described below so that a norm of a difference represented by Expression (1) is minimized.

[00002]$\begin{array}{cc}=\mathrm{MC\_g}-\mathrm{MC\_n}& \mathrm{Expression}\left(1\right)\end{array}$

[0044] MC_g in Expression (1) is the MC target value MC_g calculated in step 2. MC_n in Expression (1) is a value obtained by inputting a prediction input value related to the cold rolling to be performed next to the model M. The prediction input value corresponds to an input value input to the model M. MC_n is a vector in which prediction values of the ratios of the mechanical plate crowns to the width center plate thickness at the one or more width positions P in the rolled stock 7A manufactured by the cold rolling to be performed next are arranged. The prediction input value includes following contents (a) to (c). [0045] (a) A prediction value of a rolling load in the cold rolling to be performed next. [0046] (b) A setting value V of a work roll bending force in the cold rolling to be performed next. [0047] (c) A prediction value of width distribution of a thermal expansion amount at the work rolls 3A and 3B immediately before the cold rolling to be performed next.

[0048] The setting computer 15 predicts the value of (a) using a model calculation formula of the rolling load with the rolling conditions as an input. The setting computer 15 acquires the amount of coolant supplied to the coil 7 and the work rolls 3A and 3B, the rolling speed, the rolling load, the plate thickness, and the like in the rolling to immediately before the cold rolling to be performed next from the actual values and the rolling conditions collected by the PLC 13. The setting computer 15 predicts the value of (c) based on these values.

[0049] For example, the setting computer 15 repeatedly calculates the norm of the difference using Expression (1) while gradually changing the value of (b). For example, the setting computer 15 calculates the norm of the difference using Expression (1) for each case where the value of (b) is each of V.sub.0, V.sub.0+V, V.sub.0+2V, V.sub.0+3V, . . . , and V.sub.0+mV. V is a sufficiently small value. m is a natural number. Based on the result, the setting computer 15 selects the value of (b) at which the norm of the difference is minimum. The setting computer 15 sets the selected value of (b) as the preset value V_p of the work roll bending force in the cold rolling to be performed next. Furthermore, in order to calculate the preset value V_p more efficiently, a derivation method using a mathematical optimization method is also conceivable. For example, a method can be considered in which a problem of minimizing the norm of the difference is formulated using the model M as a nonlinear model, and V_p is obtained using a method such as a steepest descent method or a Newton method. In addition, a method of formulating a problem of minimizing the norm of the difference using the model M as a linear model by a quadratic function and obtaining V_p by a quadratic programming method is also conceivable.

[0050] In step 4 (S4), the setting computer 15 presets the preset value V_p calculated in step 3 to the shape control actuator 19.

4. Effects Achieved by Presetting Method

[0051] (1A) According to the presetting method of the present disclosure, an appropriate preset value V_p can be calculated. The appropriate preset value V_p is a preset value V_p that can bring the shape of the rolled stock 7A closer to the target shape. The appropriate preset value V_p is a preset value V_p that can reduce an amount of necessary modification of the setting value V after the cold rolling is started.

[0052] The effect achieved by the presetting method of the present embodiment was confirmed by a following simulation based on actual machine data. In the simulation, the preset value V_p was calculated by the presetting method of the present embodiment. This was compared with the actual setting value V after modification by manual intervention and feedback control in actual rolling.

[0053] Preconditions of the simulation were as follows. The material of the coil 7, the plate width of the coil 7, and the plate thickness of the rolled stock 7A are the same between the cold rolling performed immediately before the presetting method and the cold rolling to be performed immediately after the presetting method. In addition, the work rolls 3A and 3B are not replaced between the cold rolling performed immediately before the presetting method and the cold rolling to be performed immediately after the presetting method.

[0054] FIG. 3B shows a relationship between the preset value V_p and the modified setting value V. In FIG. 3B, WRB Calc. on the vertical axis means the preset value V_p. In FIG. 3B, WRB Act. on the horizontal axis means the modified setting value V. As shown in FIG. 3B, the preset value V_p is a value close to the modified setting value V.

[0055] FIG. 3A shows a result of simulation of a comparative example. In the comparative example, the model described in Japanese Unexamined Patent Application Publication No. 2003-53409 was used to calculate the preset value V_p, and the other points were similar to those of the simulation of the present embodiment. In the comparative example, as illustrated in a region 201 in FIG. 3A, the modified setting value V was sometimes greatly different from the preset value V_p.

[0056] From this simulation, it has been confirmed that an appropriate preset value V_p can be calculated according to the presetting method of the present embodiment.

Second Embodiment

1. Difference from First Embodiment

[0057] Since a basic configuration of a second embodiment is similar to that of the first embodiment, differences will be described below. Note that the same reference numerals as those in the first embodiment indicate the same configuration, and reference is made to the preceding description.

[0058] In the first embodiment described above, the preset value V_p is calculated by the presetting method illustrated in FIG. 2. The second embodiment is different from the first embodiment in that a table 101 shown in FIG. 4 is created or updated by a method illustrated in FIG. 5, and the preset value V_p is calculated by a presetting method illustrated in FIG. 6.

2. Processing of Creating and Updating Table 101

[0059] As shown in FIG. 4, the table 101 includes a plurality of pieces of data D.sub.1, D.sub.2, D.sub.3, . . . , and D.sub.n. n is a natural number of two or more. The data D.sub.i includes an MC actual value X.sub.i, a material type Y.sub.i of the rolled stock 7A, and a rolling condition Z.sub.i. i is any natural number of one or more and n or less. The MC actual value X.sub.i, the material type Y.sub.i of the rolled stock 7A, and the rolling condition Z.sub.i belonging to one piece of data D.sub.i are associated with each other. Examples of the rolling condition Z.sub.i include a rolling load, a width of the rolled stock 7A, and a plate thickness of the rolled stock 7A. The table 101 is stored in a storage unit included in the setting computer 15.

[0060] The MC actual value X.sub.i, the material type Y.sub.i of the rolled stock 7A, and the rolling condition Z.sub.i belonging to the one piece of data D.sub.i correspond to one or more times of cold rolling performed in the past. That is, the representative value or the average value of the MC actual values X.sub.i in one or more times of cold rolling performed in the past, the material type Y.sub.i of the rolled stock 7A in the cold rolling, and the rolling condition Z.sub.i in the cold rolling constitute the one piece of data D.sub.i.

[0061] Therefore, the table 101 including the MC actual value X.sub.i, the material type Y.sub.i of the rolled stock 7A, and the rolling condition Z.sub.i in association with each other for each of the plurality of times of cold rolling performed in the past is stored in the storage unit. The MC actual value X.sub.i included in the table 101 is a value calculated at a timing when the shape of the tip end of the rolled stock 7A is stable.

[0062] The setting computer 15 performs the processing illustrated in FIG. 5 for each of the plurality of times of cold rolling performed in the past, and creates and updates the table 101. In step 11 (S11) of FIG. 5, the setting computer 15 calculates the MC actual value X.sub.i for the cold rolling performed immediately before. The method of calculating the MC actual value X.sub.i is the same as that in the first embodiment.

[0063] In step 12 (S12), the setting computer 15 stores the MC actual value X.sub.i calculated in step 11 in the storage unit. In addition, the setting computer 15 stores the material type Y.sub.i of the rolled stock 7A and the rolling condition Z.sub.i in the cold rolling performed immediately before in the storage unit in association with the MC actual value X.sub.i. The MC actual value X.sub.i, the material type Y.sub.i of the rolled stock 7A, and the rolling condition Z.sub.i that have been stored are one piece of data D.sub.i and are included in the table 101.

[0064] Note that, in a case where the processing illustrated in FIG. 5 is first performed in a state where the table 101 does not exist, the table 101 is newly created. In a case where the processing illustrated in FIG. 5 is performed in a state where the table 101 already exists, data D.sub.n+1 is added to one or a plurality of pieces of data D.sub.1, D.sub.2, D.sub.3, . . . , and D.sub.n already stored, and the table 101 is updated.

3. Presetting Method

[0065] Next, a presetting method executed by the setting computer 15 according to the second embodiment instead of the presetting method according to the first embodiment will be described with reference to a flowchart of FIG. 6. The presetting method is performed between cold rolling on one coil 7 and cold rolling on the next coil 7.

[0066] In step 21 (S21) of FIG. 6, the setting computer 15 acquires a material type of the rolled stock 7A and a rolling condition in the cold rolling to be performed next from the high-order PC 17.

[0067] In step 22 (S22), the setting computer 15 selects a material type and a rolling condition closest to the material type of the rolled stock 7A and the rolling condition acquired in step 21 from among the material types of the rolled stock 7A and the rolling conditions included in the table 101. Next, the setting computer 15 extracts the MC actual value associated with the selected material type of the selected rolled stock 7A and the selected rolling condition from the table 101.

[0068] In step 23 (S23), the setting computer 15 sets the MC actual value extracted in step 22 as the MC target value MC_g.

[0069] The processing in steps 24 (S24) and 25 (S25) is similar to the processing in steps 3 and 4 in the first embodiment.

3. Effects Achieved by Presetting Method

[0070] According to the second embodiment described in detail above, the following effects can be achieved. [0071] (2A) The setting computer 15 sets the MC actual value extracted from the table 101 based on the material type of the rolled stock 7A and the rolling condition in the cold rolling to be performed next as the MC target value MC_g. Therefore, the preset calculation can be performed even in the rolling immediately after the WR replacement in which the information about the previous material cannot be used as it is.

[0072] The effect achieved by the presetting method of the present embodiment was confirmed by a following simulation based on actual machine data. In the simulation, the preset value V_p was calculated by the presetting method of the present embodiment. This was compared with the actual setting value V after modification by manual intervention and feedback control in actual rolling.

[0073] Preconditions of the simulation were as follows. The work rolls 3A and 3B are replaced between the cold rolling performed immediately before the presetting method and the cold rolling to be performed immediately after the presetting method.

[0074] A relationship between the preset value V_p and the modified setting value V is shown in FIG. 7B. In FIG. 7B, WRB Calc. on the vertical axis means the preset value V_p. In FIG. 7B, WRB Act. on the horizontal axis means the modified setting value V. As shown in FIG. 7B, the preset value V_p is a value close to the modified setting value V.

[0075] FIG. 7A shows a result of simulation of a comparative example. In the comparative example, the model described in Japanese Unexamined Patent Application Publication No. 2003-53409 was used to calculate the preset value V_p, and the other points were similar to those of the simulation of the present embodiment. In the comparative example, the modified setting value V was sometimes greatly different from the preset value V_p.

[0076] From this simulation, it has been confirmed that an appropriate preset value V_p can be calculated according to the presetting method of the present embodiment.

Third Embodiment

1. Difference from Second Embodiment

[0077] A basic configuration of a third embodiment is similar to that of the second embodiment, and thus, differences will be described below. Note that the same reference numerals as those in the second embodiment indicate the same configuration, and reference is made to the preceding description.

[0078] In the second embodiment described above, the preset value V_p is calculated by the presetting method illustrated in FIG. 6. The third embodiment is different from the second embodiment in that the preset value V_p is calculated by a presetting method illustrated in FIG. 8.

2. Presetting Method

[0079] Next, the presetting method executed by the setting computer 15 of the third embodiment instead of the presetting method of the second embodiment will be described with reference to a flowchart of FIG. 8. The presetting method is performed between cold rolling on one coil 7 and cold rolling on the next coil 7.

[0080] In step 31 (S31) of FIG. 8, the setting computer 15 acquires a material type of the rolled stock 7A and a rolling condition in the cold rolling to be performed next from the high-order PC 17.

[0081] In step 32 (S32), the setting computer 15 selects a material type and a rolling condition closest to the material type of the rolled stock 7A and the rolling condition acquired in step 31 from among the material types of the rolled stock 7A and the rolling conditions included in the table 101. Next, the setting computer 15 extracts the MC actual value associated with the selected material type of the rolled stock 7A and the selected rolling condition from the table 101.

[0082] In step 33 (S33), the setting computer 15 sets the MC actual value extracted in step 32 as a first MC target value MC_g1.

[0083] In step 34 (S34), the setting computer 15 acquires the material type of the rolled stock 7A and the rolling condition in the cold rolling performed immediately before from the high-order PC 17.

[0084] In step 35 (S35), the setting computer 15 selects a material type and a rolling condition closest to the material type of the rolled stock 7A and the rolling condition acquired in step 34 from among the material types of the rolled stock 7A and the rolling conditions included in the table 101. Next, the setting computer 15 extracts the MC actual value associated with the selected material type of the selected rolled stock 7A and the selected rolling condition from the table 101.

[0085] In step 36 (S36), the setting computer 15 sets the MC actual value extracted in step 35 as a second MC target value MC_g2.

[0086] In step 37 (S37), the setting computer 15 calculates an MC actual value by inputting, to the model M, the input data for the cold rolling performed immediately before. The method of calculating the MC actual value is similar to the processing of step 1 in the first embodiment. Next, the setting computer 15 sets the calculated MC actual value as a third MC target value MC_g3.

[0087] In step 38 (S38), the setting computer 15 calculates an MC target value MC_g based on the first MC target value MC_g1, the second MC target value MC_g2, and the third MC target value MC_g3. Specifically, the MC target value MC_g is calculated by the following Expression (2).

[00003]$\begin{array}{cc}\mathrm{MC\_g}=\mathrm{MC\_g}3+\left(\mathrm{MC\_g}1-\mathrm{MC\_g}2\right)& \mathrm{Expression}\left(2\right)\end{array}$

[0088] in Expression (2) is a coefficient. is a positive constant.

[0089] The processing in steps 39 (S39) and 40 (S40) is similar to the processing in steps 3 and 4 in the first embodiment.

3. Effects Achieved by Presetting Method

[0090] According to the third embodiment described in detail above, the effects of the first embodiment described above are achieved, and the following effects are further achieved. [0091] (3A) The setting computer 15 calculates the MC target value MC_g based on the first MC target value MC_g1, the second MC target value MC_g2, and the third MC target value MC_g3. As a result, it is possible to perform presetting based on the result of the previous material and also in consideration of the influence on the MC due to the change in the material type.

[0092] The effect achieved by the presetting method of the present embodiment was confirmed by a following simulation based on the result data. In the simulation, the preset value V_p was calculated by the presetting method of the present embodiment. This was compared with the actual setting value V after modification by manual intervention and feedback control in actual rolling.

[0093] Preconditions of the simulation were as follows. One or more of the material of the coil 7, the plate width of the coil 7, and the plate thickness of the rolled stock 7A are different between the cold rolling performed immediately before the presetting method and the cold rolling to be performed immediately after the presetting method. The work rolls 3A and 3B are not replaced between the cold rolling performed immediately before the presetting method and the cold rolling to be performed immediately after the presetting method.

[0094] A relationship between the preset value V_p and the modified setting value V is shown in FIG. 9B. In FIG. 9B, WRB Calc. on the vertical axis means a preset value V_p. In FIG. 9B, WRB Act. on the horizontal axis means a modified setting value V. As shown in FIG. 9B, the preset value V_p was a value close to the modified setting value V.

[0095] FIG. 9A shows a result of simulation of a comparative example. In the comparative example, the model described in Japanese Unexamined Patent Application Publication No. 2003-53409 was used to calculate the preset value V_p, and the other points were similar to those of the simulation of the present embodiment. In the comparative example, the modified setting value V was sometimes greatly different from the preset value V_p.

[0096] From this simulation, it has been confirmed that an appropriate preset value V_p can be calculated according to the presetting method of the present embodiment.

Other Embodiments

[0097] Although the embodiments of the present disclosure have been described above, the present disclosure is not limited to the above-described embodiments, and various modifications can be made. [0098] (1) In the first to third embodiments, preset values of setting values of an intermediate roll bender, a VC, a TP, and the like may be calculated by a presetting method. [0099] (2) In the first embodiment, the method of calculating the MC target value MC_g may be another method. For example, a value obtained by inputting the MC actual value to a predetermined function may be set as the MC target value MC_g. For example, a value obtained by multiplying the MC actual value by a predetermined coefficient may be set as the MC target value MC_g. [0100] (3) In the first embodiment, the MC actual value need not be a value calculated for the cold rolling performed immediately before. For example, the MC actual value may be a value calculated for the cold rolling performed n times before. n is a natural number of two or more. The cold rolling performed immediately before and the cold rolling performed n times before correspond to the cold rolling performed in the past. [0101] (4) In the first to third embodiments, the input data input to the model M may include various manufacturing conditions and manufacturing results in the past cold rolling. [0102] (5) In the second to third embodiments, the table 101 need not include one of the material type of the rolled stock 7A or the rolling condition. [0103] (6) In the first to third embodiments, instead of the prediction value of the width distribution of the thermal expansion amount at the work rolls 3A and 3B, the actual values of the width distribution of the thermal expansion amount at the work rolls 3A and 3B may be used. The actual values of the width distribution of the thermal expansion amount at the work rolls 3A and 3B can be measured using, for example, the sensor group 11. [0104] (7) In the first to third embodiments, preset values of two or more setting values may be calculated. [0105] (8) The setting computer 15 and the method thereof described in the present disclosure may be realized by a dedicated computer provided by configuring a processor programmed to execute one or a plurality of functions embodied by a computer program and a memory. Alternatively, the setting computer 15 and the method thereof described in the present disclosure may be realized by a dedicated computer provided by configuring a processor by one or more dedicated hardware logic circuits. Alternatively, the setting computer 15 and the method thereof described in the present disclosure may be realized by one or more dedicated computers configured by a combination of a processor programmed to execute one or a plurality of functions and a memory, and a processor configured by one or more hardware logic circuits. Furthermore, the computer program may be stored in a computer-readable non-transitory tangible recording medium as an instruction to be executed by a computer. The method of realizing the functions of the units included in the setting computer 15 does not necessarily include software, and all the functions may be realized using one or a plurality of pieces of hardware. [0106] (9) The function of one component in each of the above embodiments may be shared by a plurality of components, or the function of a plurality of components may be exerted by one component. Part of the configuration of the above embodiments may be omitted. At least part of the configuration of the above embodiments may be added to or replaced with the configuration of another above embodiment. [0107] (10) In addition to the presetting method described above, the present disclosure can be realized in various forms such as the setting computer 15, a program for causing a computer to function as the setting computer 15, a non-transitory tangible recording medium such as a semiconductor memory in which the program is recorded, a method of manufacturing the setting computer 15, and a method of manufacturing the rolled stock 7A.