METHOD OF CONTROLLING HOT FINISH ROLLING, METHOD OF CONTROLLING STEEL SHEET, AND DEVICE FOR CONTROLLING HOT FINISH ROLLING

Abstract

A method of controlling hot finish rolling, in cooperative control of the hot finish rolling, by controlling a rolling state using an evaluation function in which weight gains are set for each of a plurality of state variables and a plurality of manipulated variables and obtaining control gains that minimize the evaluation function, includes: a step of normalizing the weight gains by a normalization unit; a step of performing, by a comparative evaluation unit, comparative evaluation on the weight gains of the state variables after normalization and performing comparative evaluation on the weight gains of the manipulated variables after normalization; and a step of adjusting, by a gain adjustment unit based on a result of the comparative evaluation, at least one of: the weight gains of the state variables; and the weight gains of the manipulated variables.

Claims

1. A method of controlling hot finish rolling, in cooperative control of the hot finish rolling, by controlling a rolling state using an evaluation function in which weight gains are set for each of a plurality of state variables and a plurality of manipulated variables and obtaining control gains that minimize the evaluation function, the method comprising: a step of normalizing the weight gains by a normalization unit included in a computer; a step of performing, by a comparative evaluation unit included in the computer, comparative evaluation on the weight gains of the state variables after normalization and performing comparative evaluation on the weight gains of the manipulated variables after normalization; and a step of adjusting, by a gain adjustment unit included in the computer based on a result of the comparative evaluation, at least one of: the weight gains of the state variables; and the weight gains of the manipulated variables.

2. The method of controlling hot finish rolling according to claim 1, wherein the state variables include deviations of actual values with respect to target values of a sheet thickness of a steel sheet, a tension, and a looper angle, and the manipulated variables include a pressing position of the steel sheet, a main machine speed, and a looper torque.

3. The method of controlling hot finish rolling according to claim 1, further comprising a step of displaying whether or not adjustment of the weight gains in current cooperative control is necessary based on a comparison between a control characteristic of cooperative control in normal condition and a control characteristic of the current cooperative control with a color map by a characteristic monitoring unit included in the computer before adjustment of the weight gains.

4. The method of controlling hot finish rolling according to claim 1, wherein the gain adjustment unit is configured to adjust the at least one of the weight gains of the state variables and the weight gains of the manipulated variables by inputting the result of the comparative evaluation to a machine learning model subjected to be trained in advance by using, as input data, the result of the comparative evaluation and using, as output data, the at least one of the weight gains of the state variables after adjustment and the weight gains of the manipulated variables after adjustment, and causing the machine learning model to output at least one of the weight gains of the state variables after adjustment and the weight gains of the manipulated variables after adjustment.

5. A method of manufacturing a steel sheet, the method comprising manufacturing a steel sheet by using the method of controlling hot finish rolling according to claim 1.

6. A device for controlling hot finish rolling, in cooperative control of the hot finish rolling, by controlling a rolling state using an evaluation function in which weight gains are set for each of a plurality of state variables and a plurality of manipulated variables and obtaining control gains that minimize the evaluation function, the device comprising: a normalization unit configured to normalize the weight gains; a comparative evaluation unit configured to perform comparative evaluation on the weight gains of the state variables after normalization, and perform comparative evaluation on the weight gains of the manipulated variables after normalization; and a gain adjustment unit configured to adjust, based on a result of the comparative evaluation, at least one of: the weight gains of the state variables; and the weight gains of the manipulated variables.

7. The device for controlling hot finish rolling according to claim 6, wherein the gain adjustment unit is configured to adjust the at least one of the weight gains of the state variables and the weight gains of the manipulated variables by inputting the result of the comparative evaluation to a machine learning model subjected to be trained in advance by using, as input data, the result of the comparative evaluation and using, as output data, the at least one of the weight gains of the state variables after adjustment and the weight gains of the manipulated variables after adjustment, and causing the machine learning model to output at least one of the weight gains of the state variables after adjustment and the weight gains of the manipulated variables after adjustment.

8. A method of manufacturing a steel sheet, the method comprising manufacturing a steel sheet by using the method of controlling hot finish rolling according to claim 2.

9. A method of manufacturing a steel sheet, the method comprising manufacturing a steel sheet by using the method of controlling hot finish rolling according to claim 3.

10. A method of manufacturing a steel sheet, the method comprising manufacturing a steel sheet by using the method of controlling hot finish rolling according to claim 4.

Description

BRIEF DESCRIPTION OF DRAWINGS

[0015] FIG. 1 is a diagram illustrating an example of a configuration of hot finish rolling equipment to which a method of controlling hot finish rolling according to an embodiment of the present invention can be applied.

[0016] FIG. 2 is a diagram illustrating an example of a control block of cooperative control and an example of a gain design procedure in a method of controlling hot finish rolling according to an embodiment of the present invention.

[0017] FIG. 3 is a diagram illustrating an example of an information processing device for producing a device for controlling hot finish rolling according to an embodiment of the present invention.

[0018] FIG. 4 is a flowchart illustrating a flow of a method of controlling hot finish rolling according to an embodiment of the present invention.

[0019] FIG. 5 is a diagram illustrating an example of comparative evaluation of weight gains of state variables (controlled variables) in a comparative evaluation step of the method of controlling hot finish rolling according to an embodiment of the present invention.

[0020] FIG. 6 is a diagram illustrating an example of comparative evaluation of weight gains of manipulated variables in the comparative evaluation step of the method of controlling hot finish rolling according to an embodiment of the present invention.

[0021] FIG. 7 is a diagram illustrating an example of a simulation result in a response evaluation step of the method of controlling hot finish rolling according to an embodiment of the present invention.

[0022] FIG. 8 is a diagram illustrating an example of looper angle deviations and tension deviations before and after adjusting weight gains in a gain adjustment step of the method of controlling hot finish rolling according to an embodiment of the present invention.

[0023] FIG. 9 is a diagram illustrating an example of a color map displayed in a characteristic monitoring step of the method of controlling hot finish rolling according to an embodiment of the present invention.

DESCRIPTION OF EMBODIMENTS

[0024] A method of controlling hot finish rolling, a method of controlling a steel sheet, and a device for controlling hot finish rolling according to embodiments of the present invention will now be described with reference to the drawings. The present invention is not limited to the following embodiments, and constituent elements in the following embodiments include those that can be easily substituted by those skilled in the art or those that are substantially the same.

[Hot Finish Rolling Equipment]

[0025] FIG. 1 illustrates an example of a configuration of hot finish rolling equipment to which a method of controlling hot finish rolling according to an embodiment can be applied. In the drawing, in hot finish rolling equipment including seven rolling stands, only four rolling stands in a later stage are illustrated, and three rolling stands in an earlier stage are not illustrated. The hot finish rolling equipment includes a plurality of rolling stands 1, a plurality of roll driving devices 2, a plurality of pressing devices 3, a plurality of loopers 4, and a plurality of looper driving devices 5.

[0026] The rolling stand 1 includes work rolls and backup rolls, and uses the work rolls to roll a steel sheet S being conveyed. The roll driving device 2 drives a work roll of the rolling stand 1. The pressing device 3 presses a backup roll of the rolling stand 1. The looper 4 is placed between two rolling stands 1, and controls the tension of the steel sheet S. The looper driving device 5 changes the angle of the looper 4 (a looper angle).

[0027] In the present embodiment, the fourth rolling stand 1 from the front may be referred to as an F4 stand, the fifth rolling stand 1 as an F5 stand, the sixth rolling stand 1 as an F6 stand, and the seventh rolling stand 1 as an F7 stand as necessary. Further, in the present embodiment, the roll driving device 2 may be referred to as a main machine as necessary. Further, in the present embodiment, the looper 4 between the fourth and fifth rolling stands 1 may be referred to as an L4 looper, the looper 4 between the fifth and sixth rolling stands 1 as an L5 looper, and the looper 4 between the sixth and seventh rolling stands 1 as an L6 looper as necessary.

[Cooperative Control]

[0028] As illustrated in FIG. 1, cooperative control (finish cooperative control) of hot finish rolling according to the embodiment is performed by the four rolling stands 1 in a later stage in the hot finish rolling equipment. In this cooperative control, as illustrated in the drawing, a plurality of manipulated variable are collectively determined based on a plurality of state variables.

[0029] The state variables in the cooperative control include a deviation of an actual value with respect to a target value of the sheet thickness of the steel sheet S (hereinafter, referred to as a sheet thickness deviation) and a deviation of an actual value with respect to a target value of the tension of the steel sheet S (hereinafter, referred to as a tension deviation). Further, the state variables in the cooperative control include a deviation of an actual value with respect to a target value of the looper angle (hereinafter, referred to as a looper angle deviation). The manipulated variables in the cooperative control include the pressing position of the steel sheet S, the speed of the roll driving device 2 (hereinafter, referred to as main machine speed), and the torque of the looper 4 (hereinafter, referred to as looper torque).

[0030] In FIG. 2, the upper side illustrates an example of a control block of cooperative control of hot finish rolling according to an embodiment, and the lower side illustrates an example of a gain design procedure. As illustrated in the drawing, in the cooperative control, an evaluation function J in which weight gains Q and R are set for a plurality of state variables and a plurality of manipulated variables, respectively, is used, and control gains that minimize the evaluation function J are obtained. That is, a control model like that illustrated in the drawing is prepared, and an equation (Riccati equation) that minimizes the evaluation function J is formulated. Then, by solving this equation, an optimal input that minimizes the evaluation function J is determined. The control period of the cooperative control is preferably 10 to 30 ms. If the control period is less than 10 ms, in the control of hot finish rolling according to the present embodiment, the control period may be too short, and the risk of divergence of control may increase. If the control period is more than 30 ms, in the control of hot finish rolling according to the present embodiment, the control period may be too long, and the performance of control may deteriorate.

[0031] Here, in conventional cooperative control, weight gains set at the time of mounting are not readjusted, and the weight gains at the time of mounting are applied to a new type of steel material as they are. This is also due to the fact that the control plan of the cooperative control is difficult to understand and complicated and therefore the adjustment is troublesome. Thus, this time, starting from decipherment of the control plan, control gains are adjusted for the steel sheet S, and sheet passing is stabilized.

[Device for Controlling Hot Finish Rolling]

[0032] FIG. 3 illustrates an example of a configuration of an information processing device 100 for producing a device for controlling hot finish rolling according to an embodiment. The information processing device 100 is obtained by using, for example, a general-purpose computer such as a workstation or a personal computer. The information processing device 100 includes an input unit 10, a storage unit 20, a calculation unit 30, and an output unit 40.

[0033] The input unit 10 is a means for input to the calculation unit 30, and is obtained by using, for example, an input device such as a keyboard, a mouse pointer, or a numeric keypad. The input unit 10 inputs information necessary for various calculations in the calculation unit 30.

[0034] The storage unit 20 is obtained by using, for example, recording media such as an EPROM (erasable programmable ROM), a hard disk drive (HDD), and a removable medium. Examples of the removable medium include a disk recording medium such as a USB (universal serial bus) memory, a CD (compact disc), a DVD (digital versatile disc), or a BD (Blu-ray (registered trademark) disc).

[0035] An operating system (OS), various programs, various tables, various databases, etc. can be stored in the storage unit 20. An operational DB 21 is stored in the storage unit 20. Operational data acquired (collected) during past operations is stored in the operational DB 21.

[0036] The calculation unit 30 is obtained by using, for example, a processor composed of a CPU (central processing unit), etc. and a memory (main storage unit) composed of a RAM (random access memory), a ROM (read only memory), etc.

[0037] The calculation unit 30 loads a program into a work area of the main storage unit and executes the program to control each constituent unit, etc., and thereby implements a function according to a predetermined purpose. Through the execution of the above program, the calculation unit 30 functions as a normalization unit 31, a comparative evaluation unit 32, a response evaluation unit 33, a gain adjustment unit 34, and a characteristic monitoring unit 35. Although FIG. 3 illustrates an example of a case where the functions of the units of the calculation unit 30 are implemented by one computer, the method of implementing the functions of the units is not particularly limited, and the functions of the units may be implemented individually by, for example, a plurality of computers. Some functions of the calculation unit 30 may be provided on a cloud.

[0038] The normalization unit 31 performs a normalization step of normalizing the weight gains Q and R of the evaluation function J in the cooperative control. Details of the normalization step will be described later.

[0039] The comparative evaluation unit 32 performs a comparative evaluation step of performing comparative evaluation on the weight gains Q of the state variables after normalization by the normalization unit 31 and performing comparative evaluation on the weight gains R of the manipulated variables after normalization. Details of the comparative evaluation step will be described later.

[0040] The response evaluation unit 33 performs a response evaluation step of performing response evaluation of the state variables and the manipulated variables based on the result of comparative evaluation of the weight gains Q of the state variables after normalization and the result of comparative evaluation of the weight gains R of the manipulated variables after normalization. Details of the response evaluation step will be described later.

[0041] The gain adjustment unit 34 performs a gain adjustment step of adjusting at least one of the set of weight gains Q of the state variables and the set of weight gains R of the manipulated variables based on the comparative evaluation result of the comparative evaluation unit 32 and the response evaluation result of the response evaluation unit 33. Details of the gain adjustment step will be described later.

[0042] Before the adjustment of the weight gains Q and R, the characteristic monitoring unit 35 performs a characteristic monitoring step of displaying, with a color map, whether adjustment of the weight gains Q and R in the current cooperative control is necessary or not based on a comparison between control characteristics of cooperative control in normal condition and control characteristics of the current cooperative control. Details of the characteristic monitoring step will be described later.

[0043] The output unit 40 is an output means for outputting a result of calculation by the calculation unit 30. The output unit 40 is obtained by using, for example, an input device such as a display or a printer. The output unit 40 outputs, for example, a result of comparative evaluation of the weight gains by the comparative evaluation unit 32, a result of response evaluation of each variable by the response evaluation unit 33, a color map created by the characteristic monitoring unit 35, etc.

[Method of Controlling Hot Finish Rolling]

[0044] A method of controlling hot finish rolling according to an embodiment will now be described with reference to FIGS. 4 to 9. In the method of controlling hot finish rolling, as illustrated in FIG. 4, a normalization step (Step S1), a comparative evaluation step (Step S2), a response evaluation step (Step S3), and a gain adjustment step (Step S4) are sequentially performed. Further, in the method of controlling hot finish rolling according to the embodiment, a characteristic monitoring step is performed before Step S1 as necessary. Details of each step will now be described.

(Normalization Step)

[0045] In the normalization step, the weight gains Q and R of the evaluation function J illustrated in Formula (1) below are normalized (Step S1).

[00001]$\begin{array}{cc}\left[\mathrm{FORMULA}1\right]& \\ \mathrm{Evaluation}\mathrm{function}J={}_0^{}\left(x^T\mathrm{Qx}+u^T\mathrm{Ru}\right)\mathrm{dt}& \left(1\right)\end{array}$

[0046] In the normalization step, specifically, normalization is performed by, in the above evaluation function J, adding state variables and manipulated variables having different units with assignment of weights (weight gains). Thereby, the evaluation of each variable is visualized. The weight herein indicates an existing weight that is currently set.

[0047] For example, when focusing on the L6 looper, the weights of the state variables can be expressed by Formula (2) below. In this case, the order of the magnitudes of the weights is not simply the evaluation order of the state variables. In Formula (2) below, is the tension deviation [0.01 kgf/mm.sup.2], is the looper angle deviation [0.01 deg], and h is the sheet thickness deviation [0.01 m]. In Formula (2) below, 600 is the weight of the tension deviation, 2 is the weight of the looper angle deviation, and 15000 is the weight of the sheet thickness deviation.

[00002]$\begin{array}{cc}\left[\mathrm{FORMULA}2\right]& \\ x^T\mathrm{Qx}=600{}^2+2{}^2+15000h^2& \left(2\right)\end{array}$

[0048] In the normalization step, as illustrated in Formula (3) below, the original formula (Formula (2) above) is converted into a normalized formula. In Formula (3) below, q.sub.1, q.sub.2, q.sub.3 are true weights, and s.sub., s.sub., s.sub.h are normalization terms.

[00003]$\begin{array}{cc}\left[\mathrm{FORMULA}3\right]& \\ x^T\mathrm{Qx}=\frac{600{}^2+2{}^2+15000h^2}{\mathrm{Original}\mathrm{formula}}=\frac{{q_1\left(/s_{}\right)}^2{q_2\left(/s_{}\right)}^2+q_3{\left(h/s_h\right)}^2}{\mathrm{Formula}\mathrm{after}\mathrm{normalization}}& \left(3\right)\end{array}$

(Comparative Evaluation Step)

[0049] In the comparative evaluation step, the weights (existing weights) of the state variables and the manipulated variables after normalization are subjected to comparative evaluation (Step S2). In the comparative evaluation step, specifically, the true weights after normalization in the normalization step are subjected to comparative evaluation. For example, in the case where normalization is performed as in Formula (3) above, in the comparative evaluation step, q.sub.1=600s.sup.2.sub., q.sub.2=2s.sup.2.sub., q.sub.3=15000s.sup.2.sub.h,, which are true weights, are subjected to comparative evaluation.

[0050] FIG. 5 illustrates a result of comparative evaluation of the true weights of the state variables (q.sub.1=600s.sup.2.sub., q.sub.2=2s.sup.2.sub., q.sub.3=15000s.sup.2.sub.h mentioned above). FIG. 6 illustrates a result of comparative evaluation of the true weights of the manipulated variables. In FIG. 6, comparative evaluation is performed on the true weights of the manipulated variables in the case where the weight of the main machine speed is set to 2400, the weight of the looper torque is to 150, and the weight of the pressing position is to 200 and normalization is performed in the above normalization step.

[0051] As illustrated in FIG. 5, when the true weights of the state variables are compared, it can be seen that in the current cooperative control, the degree of priority (emphasis) decreases in the order of sheet thickness>tension>looper angle. This indicates that in the current cooperative control, weight gains Q with which the looper angle is most likely to fluctuate are set. From this, it is estimated that the responsiveness of the looper angle can be improved by increasing the weight of the looper angle.

[0052] As illustrated in FIG. 6, when the true weights of the manipulated variables are compared, it can be seen that in the current cooperative control, the degree of activeness of manipulation (the amount of manipulation) decreases in the order of looper torque>pressing position>main machine speed. This indicates that in the current cooperative control, weight gains R with which the amount of manipulation of the main machine speed is not changed much are set, that is, the main machine speed is not effectively adjusted. From this, it is estimated that the responsiveness of the looper angle and the tension can be improved by increasing the amount of manipulation of the main machine speed.

[0053] As above, in the comparative evaluation step, the weight gains of the state variables and the manipulated variables set in the current cooperative control are subjected to comparative evaluation, and thereby which variable the weight gain should be adjusted for is considered.

(Response Evaluation Step)

[0054] In the response evaluation step, response evaluation of the state variables and the manipulated variables is performed based on the result of the comparative evaluation step (Step S3). FIG. 7 illustrates an example of a simulation result in the response evaluation step.

[0055] In FIG. 7, Case 1 illustrates a result of a case where response evaluation of the looper angle and the tension is performed while the weight gains set in the current cooperative control are used as they are. Case 2 illustrates a result of a case where response evaluation of the looper angle and the tension is performed after, among the weight gains set in the current cooperative control, the weight gain of the looper angle is changed from 2 to 20.

[0056] Case 3 illustrates a case where the weight gains are changed based on the estimation result in the above comparative evaluation step. That is, Case 3 illustrates a result of a case where response evaluation of the looper angle and the tension is performed after, among the weight gains set in the current cooperative control, the weight gain of the looper angle is changed from 2 to 20 and the weight gain of the main machine speed is changed from 2400 to 1000. The action of reducing the weight gain of the main machine speed (a manipulated variable) means increasing the amount of manipulation of the main machine speed.

[0057] As illustrated in FIG. 7, it can be seen that in Cases 1 and 2, the fluctuation in the looper angle or the tension cannot be sufficiently suppressed and the response is not good. On the other hand, it can be seen that in Case 3, the fluctuations in the looper angle and the tension can be sufficiently suppressed and the response is good. That is, it can be seen that in Case 3, by changing the weight gains of the looper angle and the main machine speed, the fluctuations in the looper angle and the tension are settled and the response can be adjusted according to the weight distribution evaluated in the above comparative evaluation step.

(Gain Adjustment Step)

[0058] In the gain adjustment step, the weight gain of each variable is adjusted based on the results of the comparative adjustment step and the response evaluation step (Step S4). FIG. 8 illustrates an example of looper angle (L6 looper angle) deviations and tension (tension between F6 and F7) deviations before and after adjusting weight gains in the gain adjustment step.

[0059] As illustrated in FIG. 8, the looper angle actual result 3 before gain adjustment is 5.1 [deg], and the looper angle actual result 3 after gain adjustment is 1.6 [deg]. Thus, it can be seen that the fluctuation in the looper angle is suppressed by 68% by performing gain adjustment. Further, the tension actual result 3 before gain adjustment is 77 [0.01 kg/mm.sup.2], and the tension actual result 3 after gain adjustment is 39 [0.01 kg/mm.sup.2]. Thus, it can be seen that the fluctuation in the tension is suppressed by 49% by performing gain adjustment.

[0060] Before the adjustment of weight gains, manual operations of the pressing position, the main machine speed, etc. were frequently performed by the operator, and the cooperative control was turned off each time. As a result, a fluctuation in the looper angle or a fluctuation in the tension had been induced, and the control state had deteriorated. On the other hand, after the adjustment of weight gains, a manual operation by the operator has not occur (or the number of manual operations has been drastically reduced), and therefore the cooperative control has never been turned off. As a result, it can be seen that the fluctuation in the looper angle and the fluctuation in the tension are suppressed and control accuracy is improved. Thus, by adjusting weight gains by using the method of the present invention, very stable sheet passing can be performed.

[0061] In the gain adjustment step, the weight gain of each variable may be adjusted using a machine learning model. In this case, a machine learning model subjected to be trained in advance by using, as input data, results of the comparative adjustment step and the response evaluation step and using, as output data, at least one of the weight gains of the state variables after adjustment and the weight gains of the manipulated variables after adjustment is prepared. Then, results of the comparative adjustment step and the response evaluation step are inputted to the machine learning model, and thereby the machine learning model is caused to output at least one of the weight gains of the state variables after adjustment and the weight gains of the manipulated variables after adjustment. Thereby, at least one of the set of weight gains of the state variables and the set of weight gains of the manipulated variables is adjusted. Thus, the weight gain of each variable can be automatically adjusted by using a machine learning model in the gain adjustment step.

[0062] Here, the machine learning model used for machine learning is not particularly limited; for example, a general linear model, a tree model, an ensemble tree model, a neural network model, or the like can be used.

[0063] Examples of the general linear model include orthogonal matching tracking, Ridge regression, Lasso regression, the Elastic net (Lasso regression+Ridge regression), and the like. Examples of the tree model include a decision tree, a regression tree, and the like. Examples of the ensemble tree model include a random forest, a model obtained by adding gradient boosting to the random forest (XGBoost), a model obtained by adding gradient boosting to the decision tree (LightBGM), and the like. A neural network model can be generated using, for example, TensorFlow by Google, PyTrouch by Facebook, or the like.

(Characteristic Monitoring Step)

[0064] In the method of controlling hot finish rolling according to the embodiment, as necessary a characteristic monitoring step may be performed as a trigger for determining whether adjustment of the weight gains Q and R is necessary or not. In the characteristic monitoring step, whether adjustment of the weight gains Q and R in the current cooperative control is necessary or not is determined based on a comparison between control characteristics of cooperative control in normal condition and control characteristics of the current cooperative control. Then, whether adjustment of the weight gains Q and R is necessary or not is displayed with, for example, a color map like that illustrated in FIG. 9.

[0065] In the color map of FIG. 9, the numerical values in an upper portion represent dates, and the symbols on the right side indicate loopers 4 of L1 to L6. In the color map of the drawing, the shaded (dot hatching) portion indicates that the control characteristics of cooperative control deteriorate as the density increases. In the actual operation, the shaded portions are displayed in colors such as blue, light blue, yellow, orange, and red.

[0066] By using a color map like that illustrated in FIG. 9, for example, the operator can grasp at a glance that the control characteristics of the current cooperative control deteriorate like in an A portion; thus, the color map can be used as a trigger for adjusting the weight gains Q and R.

[0067] By using the method of controlling hot finish rolling and the device for controlling hot finish rolling according to the embodiments described hereinabove, when the control characteristics of cooperative control of hot finish rolling deteriorate, sheet passing trouble can be prevented by readjusting weight gains as necessary. Further, by using a color map (see FIG. 9) to manage and monitor the change in control characteristics of cooperative control over a long period of time, early action can be taken when sheet passing becomes unstable due to a change in characteristics of the process or a change in characteristics of the material, and thus the stability of sheet passing is improved.

[0068] Further, in a method of manufacturing a steel sheet according to an embodiment, by using the method of controlling hot finish rolling according to the embodiment, a steel sheet S can be stably manufactured while sheet passing trouble is prevented, and furthermore a contribution can be made to an improvement in the shape of the steel sheet S.

[0069] Hereinabove, a method of controlling hot finish rolling, a method of controlling a steel sheet, and a device for controlling hot finish rolling according to the present invention are specifically described using modes and examples for carrying out the invention; however, the gist of the present invention is not limited to these descriptions, and should be widely interpreted based on the description of the claims. It goes without saying that also various changes, modifications, and the like based on these descriptions are included in the gist of the present invention.

REFERENCE SIGNS LIST

[0070] 1 ROLLING STAND [0071] 2 ROLL DRIVING DEVICE [0072] 3 PRESSING DEVICE [0073] 4 LOOPER [0074] 5 LOOPER DRIVING DEVICE [0075] 10 INPUT UNIT [0076] 20 STORAGE UNIT [0077] 21 OPERATIONAL DB [0078] 30 CALCULATION UNIT [0079] 31 NORMALIZATION UNIT (NORMALIZATION MEANS) [0080] 32 COMPARATIVE EVALUATION UNIT (RESPONSE EVALUATION MEANS) [0081] 33 RESPONSE EVALUATION UNIT (RESPONSE EVALUATION MEANS) [0082] 34 GAIN ADJUSTMENT UNIT (GAIN ADJUSTMENT MEANS) [0083] 35 CHARACTERISTIC MONITORING UNIT (CHARACTERISTIC MONITORING MEANS) [0084] 100 INFORMATION PROCESSING DEVICE