PRESETTING METHOD

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims priority based on Japanese Patent Application No. 2024-158299 filed with the Japan Patent Office on Sep. 12, 2024, and the entire content of Japanese Patent Application No. 2024-158299 is incorporated herein by reference.

BACKGROUND

The present disclosure relates to a presetting method.

A cold rolling mill performs cold rolling using a work roll to produce a rolled stock. The cold rolling mill includes a shape control actuator. Examples of the shape control actuator include a work roll bender. The work roll vendor controls deflection of a work roll by adjusting a work roll bending force applied to the work roll. The shape of the rolled stock can be changed by controlling the deflection of the work roll.

Before starting the cold rolling, the work roll bending force is preset to an initial setting value. The preset initial setting value is referred to as a “preset value”. A method of presetting the work roll bending force is disclosed in Japanese Unexamined Patent Application Publication No. 2003-53409, for example. After the cold rolling is started, if necessary, feedback is performed based on the shape of the rolled stock, and the work roll bending force is modified.

SUMMARY

In the method disclosed in Japanese Unexamined Patent Application Publication No. 2003-53409, a preset value of a setting value such as a work roll bending force may be away from an appropriate value at a timing such as a material type change or immediately after WR replacement. In this case, a difference between a shape of a tip end of the rolled stock and a target shape increases, which may lead to rolling trouble and quality abnormality. In an aspect of the present disclosure, it is suitable to provide a presetting method capable of calculating an appropriate preset value even at a timing such as a material type change or immediately after WR replacement.

An aspect of the present disclosure is 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.

In the presetting method, 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 the past is input to a model, thereby calculating an MC actual value which 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. The ratio of the mechanical plate crown to the width center plate thickness is a value obtained by dividing the mechanical plate crown by the width center plate thickness. The ratios of the mechanical plate crowns to the width center plate thickness are calculated at the plurality of width positions respectively, and a vector obtained by arranging the ratios is the MC actual value.

In the presetting method, based on the MC actual value, an MC target value MC_g, which 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 manufactured by the cold rolling to be performed next are arranged, is calculated.

In the presetting method, the setting value in the cold rolling to be performed next is selected so that a norm of a difference Δ represented by following Expression (1) is minimized, and the selected setting value is set as the preset value,

Δ = MC_g - MC_n , Expression ⁢ ( 1 )

• • 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 the width distribution of the thermal expansion amount at the work roll immediately before the cold rolling to be performed next.

According to the presetting method that is an aspect of the present disclosure, an appropriate preset value can be calculated.

BRIEF DESCRIPTION OF THE DRAWINGS

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

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

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

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

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

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

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

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

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

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

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

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

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

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.

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.

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.

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.

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

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.

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

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.

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).

• • (a) An actual value of a rolling load in the cold rolling performed immediately before.
  • (b) A setting value V of a work roll bending force in the cold rolling performed immediately before.
  • (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.

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.

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.

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.

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.

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_Pc. The plate thickness of the coil 7 at the width position P is denoted by D_P. The mechanical plate crown at the width position P is a value obtained by subtracting the plate thickness D_P from the width center plate thickness D_Pc. A value obtained by dividing the mechanical plate crown by the width center plate thickness D_Pc is a ratio of the mechanical plate crown to the width center plate thickness.

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.

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 Δ represented by Expression (1) is minimized.

Δ = MC_g - MC_n Expression ⁢ ( 1 )

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′).

• • (a′) A prediction value of a rolling load in the cold rolling to be performed next.
  • (b′) A setting value V of a work roll bending force in the cold rolling to be performed next.
  • (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.

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.

For example, the setting computer 15 repeatedly calculates the norm of the difference Δ using Expression (1) while gradually changing the value of (b′). For example, the setting computer 15 calculates the norm of the difference Δ using Expression (1) for each case where the value of (b′) is each of V₀, V₀+δV, V₀+2δV, V₀+3δV, . . . , and V₀+mδV. δV 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 Δ 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 Δ 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 Δ using the model M as a linear model by a quadratic function and obtaining V_p by a quadratic programming method is also conceivable.

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

• • (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.

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.

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.

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.

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.

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

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.

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

As shown in FIG. 4, the table 101 includes a plurality of pieces of data D₁, D₂, D₃, . . . , and D_n. n is a natural number of two or more. The data D_i includes an MC actual value X_i, a material type Y_i of the rolled stock 7A, and a rolling condition Z_i. i is any natural number of one or more and n or less. The MC actual value X_i, the material type Y_i of the rolled stock 7A, and the rolling condition Z_i belonging to one piece of data D_i are associated with each other. Examples of the rolling condition Z_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.

The MC actual value X_i, the material type Y_i of the rolled stock 7A, and the rolling condition Z_i belonging to the one piece of data D_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_i in one or more times of cold rolling performed in the past, the material type Y_i of the rolled stock 7A in the cold rolling, and the rolling condition Z_i in the cold rolling constitute the one piece of data D_i.

Therefore, the table 101 including the MC actual value X_i, the material type Y_i of the rolled stock 7A, and the rolling condition Z_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_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.

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_i for the cold rolling performed immediately before. The method of calculating the MC actual value X_i is the same as that in the first embodiment.

In step 12 (S12), the setting computer 15 stores the MC actual value X_i calculated in step 11 in the storage unit. In addition, the setting computer 15 stores the material type Y_i of the rolled stock 7A and the rolling condition Z_i in the cold rolling performed immediately before in the storage unit in association with the MC actual value X_i. The MC actual value X_i, the material type Y_i of the rolled stock 7A, and the rolling condition Z_i that have been stored are one piece of data D_i and are included in the table 101.

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_n+1 is added to one or a plurality of pieces of data D₁, D₂, D₃, . . . , and D_n already stored, and the table 101 is updated.

3. Presetting Method

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.

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.

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.

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

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

According to the second embodiment described in detail above, the following effects can be achieved.

• • (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.

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.

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.

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.

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.

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

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.

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

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.

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.

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.

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.

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.

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.

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.

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.

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).

MC_g = MC_g ⁢ 3 + α × ( MC_g ⁢ 1 - MC_g ⁢ 2 ) Expression ⁢ ( 2 )

α in Expression (2) is a coefficient. α is a positive constant.

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

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.

• • (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.

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.

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.

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.

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.

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

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.

• • (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.
  • (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.
  • (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.
  • (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.
  • (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.
  • (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.
  • (7) In the first to third embodiments, preset values of two or more setting values may be calculated.
  • (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.
  • (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.
  • (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.