JP2015147249A - Rolling machine control method, rolling machine control apparatus, and manufacturing method of rolled material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simultaneously estimate at low cost, deformation resistance and a friction coefficient between a rolled target material and a pressure roll, and to suppress, in rolling, dimensional defects of the rolled material from occurring and rolling efficiency from deteriorating.SOLUTION: In a rolling machine control apparatus 1 as an embodiment of the present invention, an estimation unit 6 solves an optimization problem of calculating deformation resistance k of a rolled target material S and a friction coefficient μ between the rolled target material and a pressure roll, in which an evaluation function J satisfies a predetermined condition, thereby calculates the deformation resistance k of the rolled target material S and the friction coefficient μ between the rolled target material S and the pressure roll. By this, the deformation resistance k and the friction coefficient μ between the rolled target material and the pressure roll can be simultaneously and highly accurately calculated at low cost, and occurrence of dimensional defects of the rolled material and deterioration of rolling efficiency can be suppressed during rolling.

Description

  The present invention relates to a rolling mill control method, a rolling mill control device, and a rolled material manufacturing method.

  In the rolling process, the material to be rolled must be rolled to a desired finish size and shape under various constraints such as reduction amount, rolling speed, and rolling load. Therefore, in the rolling process, the rolling mill setting calculation (setup calculation) is performed based on the material specifications of the rolled material before the rolled material enters the rolling mill, and the rolling load and roll peripheral speed of the rolling mill are executed. Etc. must be set to appropriate values.

  The rolling mill setting calculation is based on the deformation resistance of the material to be rolled and the friction coefficient between the material to be rolled and the rolling roll (hereinafter abbreviated as deformation resistance and friction coefficient), which is a value determined by the material specifications of the material to be rolled. Used to solve the rolling model equation. For this reason, when the deformation resistance and the friction coefficient include an error, the error affects the set value of the rolling mill, and causes a dimensional defect of the material to be rolled during rolling and a reduction in rolling efficiency.

  Therefore, it is necessary to accurately measure the deformation resistance and the friction coefficient in order to suppress the dimension failure of the material to be rolled during rolling and the reduction in rolling efficiency. However, the deformation resistance and the coefficient of friction are values that cannot be directly measured. From such a background, a technique for estimating a deformation resistance and a friction coefficient using values that can be directly measured such as a rolling load and a thickness of a material to be rolled has been proposed.

  Specifically, Patent Document 1 describes a technique for measuring the advanced rate using a plate speedometer installed on the exit side of the rolling mill and estimating the friction coefficient from the measured advanced rate. . Patent Document 2 describes a technique for estimating the deformation resistance from the rolling load and the thickness of the material to be rolled on the exit side of the rolling mill. Patent Document 3 describes a technique for estimating the deformation resistance and the friction coefficient in accordance with the rolling speed state.

JP-A-2-20605 Japanese Patent Laid-Open No. 9-16412 Japanese Patent Application Laid-Open No. 8-283121

  However, according to the technique described in Patent Document 1, the plate speedometer is expensive, and it is difficult to maintain the measurement accuracy of the plate speedometer in a bad environment around the rolling mill. It costs a lot of money. According to the technique described in Patent Document 2, since a fixed value is used for the friction coefficient, if the friction coefficient includes an error, the error is treated as an estimation error of the deformation resistance. Further, according to the technique described in Patent Document 3, when the rolling speed is changed, the friction coefficient is made constant, and when the friction coefficient is changed, the rolling speed is made constant and the rolling speed and the friction coefficient are separated. Therefore, the deformation resistance and the friction coefficient cannot be estimated at the same time.

  The present invention has been made in view of the above problems, and its object is to simultaneously improve the deformation resistance of the material to be rolled and the coefficient of friction between the material to be rolled and the rolling roll without much cost. An object of the present invention is to provide a rolling mill control method and a control apparatus that can estimate and suppress a dimensional defect of a material to be rolled during rolling and a reduction in rolling efficiency. Another object of the present invention is to provide a method for producing a rolled material that can suppress a dimensional defect of the material to be rolled during rolling and a decrease in rolling efficiency and can improve the yield.

  The rolling mill control method according to the present invention includes a measuring step of measuring a sheet thickness of a material to be rolled on a delivery side of each rolling stand constituting the rolling mill, a roll peripheral speed and a rolling load of each rolling stand, and the measurement Using the plate thickness of the material to be rolled at the exit side of each rolling stand measured in the step, at least the deformation resistance of the material to be rolled, the friction coefficient between the material to be rolled and the rolling roll, and the entry side of each rolling stand And calculating the rolling load and the advance rate of each rolling stand by solving the rolling model formula including the sheet thickness of the material to be rolled on the exit side as a variable, and each rolling measured in the measurement step according to the constant mass flow rule A calculating step for calculating a mass flow amount of each rolling stand using a plate thickness of the material to be rolled and a roll peripheral speed and an advance rate on the exit side of the stand; A term indicating an error between the rolling load of each rolling stand measured in the step and the rolling load of each rolling stand calculated in the calculating step, and the muff flow amount calculated in the calculating step between the rolling stands. An optimization step for calculating the deformation resistance and the friction coefficient by solving an optimization problem for obtaining the deformation resistance and the friction coefficient, wherein the evaluation function including at least an evaluation function that satisfies a predetermined condition; And a control step of controlling a rolling process of the material to be rolled by a rolling mill using the deformation resistance and the friction coefficient calculated in the optimization step.

  The control device for a rolling mill according to the present invention includes a measuring means for measuring a thickness of a material to be rolled on a delivery side of each rolling stand constituting the rolling mill, a roll peripheral speed and a rolling load of each rolling stand, and the measurement Using the thickness of the material to be rolled on the exit side of each rolling stand measured by the means, at least the deformation resistance of the material to be rolled, the coefficient of friction between the material to be rolled and the rolling roll, and the entry side of each rolling stand And calculating the rolling load and the advanced rate of each rolling stand by solving the rolling model formula including the sheet thickness of the material to be rolled on the exit side as a variable, and each rolling measured by the measuring means according to the constant mass flow amount rule The calculation means for calculating the mass flow amount of each rolling stand using the plate thickness of the material to be rolled and the roll peripheral speed and the advance rate on the exit side of the stand, and the measurement means A term indicating an error between the rolling load of each rolling stand and the rolling load of each rolling stand calculated by the calculating unit, and a term indicating an error between the rolling stands of the muff flow amount calculated by the calculating unit; , An evaluation function including at least a predetermined condition satisfying a predetermined condition, an optimization means for calculating the deformation resistance and the friction coefficient by solving the optimization problem, and the optimization means calculating the deformation resistance and the friction coefficient Control means for controlling a rolling process of the material to be rolled by a rolling mill using the deformation resistance and the friction coefficient.

  The method for manufacturing a rolled material according to the present invention includes a step of manufacturing the rolled material using a rolling mill including the rolled material control device according to the present invention.

  According to the control method and control device for a rolling mill according to the present invention, the deformation resistance of the material to be rolled and the friction coefficient between the material to be rolled and the rolling roll are estimated simultaneously with high accuracy without much cost, and rolling is performed. It is possible to suppress a dimensional defect of the material to be rolled and a reduction in rolling efficiency. According to the method for manufacturing a rolled material according to the present invention, it is possible to suppress a dimensional defect of the material to be rolled at the time of rolling and a decrease in rolling efficiency, and to improve the yield.

FIG. 1 is a block diagram showing a configuration of a rolling mill control apparatus according to an embodiment of the present invention. FIG. 2 is a flowchart showing a flow of deformation resistance and friction coefficient estimation processing according to an embodiment of the present invention. FIG. 3 is a diagram showing actual values of the exit side plate thickness, rolling load, and roll peripheral speed of the material to be rolled, and the longitudinal deformation resistance, the friction coefficient, and the advanced rate of the material to be rolled estimated using the present invention. It is.

  Hereinafter, a rolling mill control apparatus according to an embodiment of the present invention will be described in detail with reference to the drawings.

〔Constitution〕
First, with reference to FIG. 1, the structure of the control apparatus of the rolling mill which is one Embodiment of this invention is demonstrated.

  FIG. 1 is a block diagram showing a configuration of a rolling mill control apparatus according to an embodiment of the present invention. As shown in FIG. 1, the control apparatus 1 of the rolling mill which is one Embodiment of this invention is an apparatus which controls the rolling process which rolls the to-be-rolled material S using N rolling stands. The control device 1 includes a thickness gauge 2, a load measuring device 3, a roll peripheral speed measuring device 4, an actual value collection unit 5, an estimation unit 6, a setting calculation unit 7, and a control unit 8.

  The plate thickness meter 2 is an apparatus that is installed on the downstream side in the conveying direction of the material to be rolled S of each rolling stand (hereinafter referred to as the outlet side) and measures the plate thickness of the material to be rolled S rolled at each rolling stand. is there.

  The load measuring device 3 is a device that measures the rolling load of each rolling stand.

  The roll peripheral speed measuring device 4 is a device that measures the peripheral speed of the rolling roll of each rolling stand.

  The actual value collecting unit 5 collects the measured values of the plate thickness meter 2, the load measuring device 3, and the roll peripheral speed measuring device 4, and uses the collected measured values as the plate thickness, rolling load, and roll circumference of the material S to be rolled. It is a device that outputs to the estimation unit 6 as an actual speed value.

  The estimation unit 6 uses the actual values of the sheet thickness, rolling load, and roll peripheral speed of the material to be rolled S output from the result value collecting unit 5, and the deformation resistance of the material to be rolled S, the material to be rolled S, and each of the materials. It is an apparatus for estimating a friction coefficient (hereinafter abbreviated as deformation resistance and friction coefficient) between the rolling rolls of a rolling stand. The estimation unit 6 outputs the estimated deformation resistance and friction coefficient data to the setting calculation unit 7.

  The setting calculation unit 7 calculates setting values of each rolling stand such as a rolling load and a roll peripheral speed by solving the rolling model formula using the data of the deformation resistance and the friction coefficient, and sets the calculated setting of each rolling stand. It is a device that outputs a value to the control unit 8.

  The control unit 8 is a device that controls the rolling process of the material to be rolled S in each rolling stand based on the set value of each rolling stand output from the setting calculation unit 7.

  In the control apparatus 1 of the rolling mill having such a configuration, the estimation unit 6 executes the estimation process shown below, thereby simultaneously estimating the deformation resistance and the friction coefficient. Hereinafter, the operation of the estimation unit 6 when executing this estimation process will be described in detail.

[Estimation process]
In general, the rolling load P and the advance rate f are expressed by the deformation resistance k of the material to be rolled S as shown in the following formulas (1) and (2), the friction coefficient μ between the material to be rolled S and the rolling roll, It can be expressed as a nonlinear function using parameters such as the entry side thickness H of the rolled material S and the exit side thickness h of the material to be rolled S.

Further, for the mass flow amount MS _i represented by the following mathematical formula (3), the mass flow amount constant law is assumed that the mass flow amount is constant on the entry side and the exit side of each rolling stand. In Equation (3), i (= 1 to N) is a rolling stand number, and V is a roll peripheral speed of the rolling stand.

In order to calculate the mass flow amount MS _i represented by Equation (3), the advanced rate f represented by Equation (2) is required. Here, the rolling load P, the entry side plate thickness H, the exit side plate thickness h, and the roll peripheral speed V are values that can be measured. For this reason, it is impossible to actually measure by solving the rolling model formulas shown in the formulas (1) and (2) using the actual values of the rolling load P, the entry side thickness H, the exit side thickness h, and the roll peripheral speed V. The deformation resistance k and the friction coefficient μ can be estimated.

However, since the number of unknown variables exceeds the number of relational expressions given by the mathematical expressions (1) to (3), the deformation resistance k and the friction coefficient μ are derived by solving the mathematical expressions (1) to (3). I can't. Therefore, in the present embodiment, an evaluation function J expressed by the following formula (4) is defined, and the problem of deriving the deformation resistance k and the friction coefficient μ is a deformation resistance k and friction that minimizes the value of the evaluation function J. Consider it as an optimization problem to derive the coefficient μ. As a solution to the optimization problem, a particle swarm optimization technique, a genetic algorithm, or the like can be used. In Equation (4), P _act and P _cal are actual values and calculated values of the rolling load P, N is the number of rolling stands, w ₁ , w ₂ and w ₃ are weighting factors, and g is a constraint condition.

The first term on the right side of Equation (4) evaluates an error between the actual value _{Pact of the} rolling load P and the calculated value _Pcal of the rolling load P obtained by Equation (1). Further, the second term on the right side is an evaluation of the error between the rolling stands of the mass flow amount MS _i obtained by Equation (3), that is, the error of the advanced rate f obtained by Equation (2). is there. The third term on the right side is a constraint condition for the evaluation function J. By introducing the constraint condition, the solution (the deformation resistance k and the friction coefficient μ) that minimizes the evaluation function J can be limited. A weighting coefficient is provided for each of these terms, and it is determined to which term the error is to be distributed.

  As a constraint condition, for example, a condition that the change in the friction coefficient μ is minute in a minute section in the length direction of the material S to be rolled can be exemplified as in the following formula (5). However, in Formula (5), k has shown the arbitrary sample points of the length direction of the to-be-rolled material S. FIG. The solution that minimizes the evaluation function J can be limited by assuming that the friction coefficient μ is locally equal in a minute section in the length direction.

The flow of the above estimation process is summarized as a flowchart shown in FIG. That is, as shown in FIG. 2, in the estimation process according to an embodiment of the present invention, first, the estimation unit 6 prepares arbitrary initial solutions of the deformation resistance k and the friction coefficient μ (step S <b> 1). Rolling load P _cal , advanced rate f by rolling model formula using arbitrary initial solution of resistance k and friction coefficient μ, rolling load P, inlet side plate thickness H, outlet side plate thickness h, and actual value of roll peripheral speed V And the mass flow amount MS _i are calculated (step S2). Then, the estimating unit 6, using rolling load P, thickness at entrance side H, delivery side thickness h, and actual values and rolling load P _cal roll peripheral speed _V, forward slip f, and the mass flow quantity MS _i Rating The value of function J is calculated (step S3).

  Next, the estimation unit 6 determines whether or not the value of the evaluation function J calculated by the process of step S3 is equal to or greater than a predetermined threshold Th (step S4). As a result of determination, when the value of the evaluation function J is equal to or greater than the predetermined threshold Th, the estimation unit 6 corrects the values of the deformation resistance k and the friction coefficient μ used in the process of Step S2 (Step S5), and then estimates. The process returns to the process of step S2. On the other hand, when the value of the evaluation function J is less than the predetermined threshold Th, the estimation unit 6 outputs the values of the deformation resistance k and the friction coefficient μ used in the process of step S2 to the setting calculation unit 7 as optimum solutions. (Step S6). Thereby, a series of estimation processes is completed.

  As is apparent from the above description, in the rolling mill control apparatus 1 according to an embodiment of the present invention, the estimation unit 6 has a deformation resistance k and a friction coefficient μ that minimize the evaluation function J shown in Equation (4). Since the deformation resistance k and the friction coefficient μ are calculated by solving the optimization problem, the deformation resistance k and the friction coefficient μ are estimated with high accuracy at the same time without requiring much cost. Dimensional defects and reduction in rolling efficiency can be suppressed.

  In the present embodiment, the deformation resistance k and the friction coefficient μ that minimize the evaluation function J are obtained. However, the present invention is not limited to the present embodiment, and is near the minimum value of the evaluation function J. The deformation resistance k and the friction coefficient μ may be obtained. That is, the condition of the evaluation function J for obtaining the deformation resistance k and the friction coefficient μ can be changed as appropriate according to the form of the evaluation function J and various constraint conditions.

  FIG. 3 shows (a) an exit side plate thickness h of a material to be rolled in a seventh rolling stand when a material to be rolled having a finishing thickness of 2.8 mm and a finishing width of 1340 mm is rolled by a finishing rolling mill of a hot rolling line. b) Actual value of rolling load P and (c) Roll peripheral speed V, (d) Deformation resistance k in the longitudinal direction of the rolled material estimated using the present invention, (e) Friction coefficient μ, and (f ) Is a diagram showing the advanced rate f.

In the present embodiment, the values of the weighting factors w ₁ , w ₂ , and w ₃ included in the evaluation function J shown in Equation (4) are all 1, and the constraint condition shown in Equation (5) is used as the constraint condition. Further, the threshold value Th of the evaluation function J was set to 0.0003, and the particle swarm optimization method was used as a solution to the optimization problem. As shown in FIG. 3, according to the present invention, it was confirmed that the deformation resistance k and the friction coefficient μ can be estimated simultaneously along the longitudinal direction of the material to be rolled.

  Although the embodiment to which the invention made by the present inventor is applied has been described above, the present invention is not limited by the description and the drawings that form a part of the disclosure of the present invention according to this embodiment. That is, other embodiments, examples, operational techniques, and the like made by those skilled in the art based on this embodiment are all included in the scope of the present invention.

DESCRIPTION OF SYMBOLS 1 Control apparatus 2 Sheet thickness meter 3 Load measuring apparatus 4 Rolling roll peripheral speed measuring apparatus 5 Actual value collection part 6 Estimation part 7 Setting calculation part 8 Control part

Claims (5)

A measuring step for measuring the thickness of the material to be rolled on the exit side of each rolling stand constituting the rolling mill, the roll peripheral speed of each rolling stand, and the rolling load;
Using the plate thickness of the material to be rolled on the exit side of each rolling stand measured in the measuring step, at least the deformation resistance of the material to be rolled, the friction coefficient between the material to be rolled and the rolling roll, and each rolling stand The rolling load equation and the advanced rate of each rolling stand are calculated by solving the rolling model formula including the sheet thickness of the material to be rolled on the entry side and the exit side as a variable, and measured in the measurement step according to the mass flow amount constant law. A calculation step for calculating the mass flow amount of each rolling stand using the sheet thickness and roll peripheral speed and the advance rate of the material to be rolled on the exit side of each rolling stand,
A term indicating an error between the rolling load of each rolling stand measured in the measuring step and the rolling load of each rolling stand calculated in the calculating step, and between each rolling stand of the muff flow amount calculated in the calculating step An optimization step for calculating the deformation resistance and the friction coefficient by solving an optimization problem for obtaining the deformation resistance and the friction coefficient, wherein an evaluation function including at least an evaluation function that satisfies a predetermined condition,
A control step of controlling a rolling process of the material to be rolled by a rolling mill using the deformation resistance and the friction coefficient calculated in the optimization step;
A control method for a rolling mill, comprising:   The optimization step includes a step of solving the optimization problem using a constraint condition that a change in a friction coefficient is minute in a minute section in a length direction of the material to be rolled. The rolling mill control method described.   The rolling mill control method according to claim 1 or 2, wherein the predetermined condition is that the value of the evaluation function is minimized. Measuring means for measuring the sheet thickness of the material to be rolled on the exit side of each rolling stand constituting the rolling mill, the roll peripheral speed of each rolling stand, and the rolling load;
Using the plate thickness of the material to be rolled on the exit side of each rolling stand measured by the measuring means, at least the deformation resistance of the material to be rolled, the friction coefficient between the material to be rolled and the rolling roll, and each rolling stand The rolling load equation and the advanced rate of each rolling stand were calculated by solving the rolling model formula including the sheet thickness of the material to be rolled on the entry side and the exit side as a variable, and measured by the measuring means according to the constant mass flow amount rule. Calculation means for calculating the mass flow amount of each rolling stand using the sheet thickness and roll peripheral speed and the advance rate of the material to be rolled on the exit side of each rolling stand,
A term indicating an error between the rolling load of each rolling stand measured by the measuring means and the rolling load of each rolling stand calculated by the calculating means, and between each rolling stand of the muff flow amount calculated by the calculating means An optimization means for calculating the deformation resistance and the friction coefficient by solving an optimization problem for obtaining the deformation resistance and the friction coefficient, wherein the evaluation function including at least an evaluation function that satisfies a predetermined condition,
Control means for controlling the rolling process of the material to be rolled by a rolling mill using the deformation resistance and the friction coefficient calculated by the optimization means;
A control device for a rolling mill, comprising:   A method for producing a rolled material, comprising the step of producing a rolled material using a rolling mill comprising the rolling material control device according to claim 4.

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