JP2021126684A - Control device for rolling device, control method for rolling device, and control program for rolling device - Google Patents

Abstract

To provide a control device for a rolling device which improves a quality of a rolled material.SOLUTION: A control device 60 for a rolling device for controlling a rolling device 100 has a rough rolling mill 10 and a finish rolling mill 20 for rolling a rolled material 1, a temperature measurement part 15 for measuring a temperature of the rolled material arranged between the rough rolling mill and the finish rolling mill, and temperature adjustment parts 30, 40 and 51 to 56 for adjusting a temperature of the rolled material arranged between the temperature measurement part and the finish rolling mill outlet. The control device includes: a temperature acquisition part for acquiring a temperature of the rolled material at a plurality of control points set in the rolled material; an operation amount setting part for setting operation amounts of the plurality of temperature adjustment parts so that the temperatures of the plurality of control points at a plurality of temperature management positions P satisfy temperature conditions determined for each of the temperature management positions; and an output part for outputting each of the operation amounts set by the operation amount setting part, to the corresponding temperature adjustment parts. The plurality of temperature management positions include a temperature management position P2 set on the finish rolling device outlet side and a temperature management position P1 set in the finish rolling device.SELECTED DRAWING: Figure 1

Description

The present invention relates to a control device for a rolling apparatus, a control method for a rolling apparatus, and a control program for a rolling apparatus.

The hot-rolled thin steel sheet is manufactured by the following process. First, the slab, which is a rolled material, is heated in a heating furnace. After that, rough rolling is performed with a rough rolling machine to make the slab a rough bar. Subsequently, the rough bar is finished-rolled by a finishing tandem rolling mill (finishing rolling mill) composed of a plurality of stands to manufacture a hot-rolled thin steel sheet.
In finish rolling, the temperature on the outlet side (temperature control position) of the finish tandem rolling mill is controlled in order to ensure the mechanical properties of the rolled material such as strength and ductility. The temperature control unit for adjusting the temperature of the rolled material is a coarse bar heater that heats the rough bar between the rough rolling mill and the finishing tandem rolling mill, and cools the rough bar between the rough rolling mill and the finishing tandem rolling mill. A coarse bar cooling device, a cooling spray device for cooling the rolled material between the stands of the finishing tandem rolling mill, and the like are used.
As a temperature control method, there is a technique disclosed in Patent Document 1.

In the method disclosed in Patent Document 1, a plurality of control points are set on the coarse bar over the transport direction of the coarse bar. Then, the temperature on the outlet side of the rough rolling mill at each control point is measured, and the rough bar heater and the cooling spray device are operated so that the temperature on the outlet side of the finishing tandem rolling mill at each control point becomes the target temperature.

Japanese Unexamined Patent Publication No. 2002-219504

In recent years, there has been a demand for further improving the quality of rolled materials from the following plurality of viewpoints. One of the plurality of viewpoints is to improve the mechanical properties of the rolled material. In the other one of the plurality of viewpoints, the rolling roll of the rolling apparatus is heated by the heat of the rolled material to cause surface roughness on the rolling roll, and this surface roughness is transferred to the rolled material to transfer the surface of the steel sheet. It is to prevent the properties from deteriorating. Another one of the plurality of viewpoints is to prevent scale defects of the rolled material caused by the scale when the scale of the peeled rolled material is rolled together with the rolled material.

The present invention has been made in view of such problems, and provides a rolling device control device, a rolling device control method, and a rolling device control program in which the quality of the rolled material is further improved. With the goal.

In order to solve the above problems, the present invention proposes the following means.
The control device of the rolling apparatus of the present invention is a rough rolling machine and a finishing rolling machine that rolls a rolled material on a transport path, and a rolling material of the rolled material between the rough rolling mill outlet and the finishing rolling mill inlet on the transport path. Controlling a rolling apparatus including a temperature measuring unit for measuring the temperature and a plurality of temperature adjusting units for adjusting the temperature of the rolled material between the temperature measuring unit on the transport path and the outlet of the finishing rolling mill. A control device for a rolling apparatus for rolling the rolled material, wherein the temperature of the rolled material is set at a plurality of control points set for the rolled material at intervals in the transport direction in which the rolled material is conveyed. In each of the temperature acquisition unit acquired from the temperature measurement unit and the plurality of preset temperature control positions, the temperatures of the plurality of control points are equal to or higher than the lower limit temperature and the upper limit temperature set in advance for each of the temperature control positions. An operation amount setting unit for setting the operation amount of each of the plurality of temperature control units and each of the operation amounts set by the operation amount setting unit to the corresponding temperature control units so as to satisfy the temperature condition to be settled. The plurality of temperature control positions include an output unit for outputting, and the plurality of temperature control positions are a temperature control position set on the transport path on the outlet side of the finish rolling mill and a temperature set on the transport path in the finish rolling mill. It is characterized by including a control position.

Further, the control method of the rolling apparatus of the present invention is a portion between a rough rolling mill and a finishing rolling mill that rolls a rolled material on a transport path, and an outlet of the rough rolling mill and an inlet of the finishing rolling mill on the transport path. Rolling provided with a temperature measuring unit for measuring the temperature of the rolled material and a plurality of temperature adjusting units for adjusting the temperature of the rolled material in a portion between the temperature measuring unit on the transport path and the outlet of the finishing rolling mill. A method for controlling a rolling apparatus that controls an apparatus to roll the rolled material, wherein the rolled material is set at a plurality of control points set on the rolled material at intervals in a transport direction in which the rolled material is conveyed. The temperature acquisition step of acquiring the temperature of each from the temperature measuring unit and the temperature of the plurality of control points at each of the plurality of preset temperature control positions are equal to or higher than the lower limit temperature predetermined for each of the temperature control positions. The operation amount setting step of setting the operation amount of each of the plurality of temperature control units so as to satisfy the temperature condition within the upper limit temperature, and the corresponding plurality of operation amounts set by the operation amount setting step. The output steps of outputting to the temperature control unit of the above are performed, and the plurality of temperature control positions are the temperature control position set on the transfer path on the outlet side of the finish rolling mill and the transfer in the finish rolling mill. It is characterized by including a temperature control position set on the road.

Further, the control program of the rolling apparatus of the present invention covers a portion between a rough rolling mill and a finishing rolling mill that rolls a rolled material on a transport path, and an outlet of the rough rolling mill and an inlet of the finishing rolling mill on the transport path. Rolling provided with a temperature measuring unit for measuring the temperature of the rolled material and a plurality of temperature adjusting units for adjusting the temperature of the rolled material in a portion between the temperature measuring unit on the transport path and the outlet of the finishing rolling mill. A control program for a rolling apparatus for a control device that controls an apparatus to roll the rolled material, and the control device is set on the rolled material at intervals in a transport direction in which the rolled material is conveyed. The temperature acquisition unit that acquires the temperature of the rolled material at each of the plurality of control points from the temperature measurement unit, and the temperatures of the plurality of control points at each of the plurality of preset temperature control positions are set for each of the temperature control positions. An operation amount setting unit that sets the operation amount of each of the plurality of temperature control units and each set by the operation amount setting unit so as to satisfy a temperature condition that is equal to or higher than a predetermined lower limit temperature and lower than the upper limit temperature. The operation amount is made to function as an output unit that outputs to the corresponding temperature control unit, and the plurality of temperature control positions are the temperature control positions set on the transport path on the exit side of the finish rolling mill. Further, it is characterized by including a temperature control position set on the transport path in the finish rolling mill.

According to these inventions, the temperature acquisition unit (in the temperature acquisition step) acquires the temperature of the rolled material at a plurality of control points set for the rolled material from the temperature measurement unit. Depending on the operation amount setting unit (in the operation amount setting process), the temperatures of the plurality of control points at each of the plurality of preset temperature control positions are within the lower limit temperature and the upper limit temperature set in advance for each temperature control position. Set multiple operation amounts so as to satisfy the temperature condition. Then, the temperature of the rolled material was controlled by outputting each operation amount set by the output unit (in the output process) and by the operation amount setting unit (in the operation amount setting process) to the corresponding temperature control unit. The rolled material is rolled in this state.
At this time, the plurality of temperature control positions are not only the temperature control positions set on the transport path on the outlet side of the finish rolling mill, which is the position outside the finish rolling mill, but also the positions inside the finish rolling mill, which are the positions inside the finish rolling mill. Includes temperature control positions set on the transport path. Therefore, the temperature of the plurality of control points is equal to or higher than the predetermined lower limit temperature and lower than the upper limit temperature for each temperature control position not only at the temperature control position outside the finish rolling mill but also at the temperature control position inside the finish rolling mill. It fits. Therefore, since the temperatures of the plurality of control points of the rolled material are further stabilized, the quality of the rolled material can be further improved.

Further, in the control device of the rolling apparatus, the number of the plurality of temperature control units is _Nj, and among the plurality of control points, the kth control point from the downstream side to the upstream side in the transport direction is designated as the kth control point. The i-th temperature control position from the upstream side to the downstream side in the transport direction is set as the i-th temperature control position among the plurality of temperature control positions, and the above-mentioned of the plurality of temperature control units. The j-th temperature control unit from the upstream side to the downstream side in the transport direction is the j-th temperature control unit, and the i-th temperature control position at the i-th temperature control position when the operation amount of each of the plurality of temperature control units is set to 0. The temperature of the k-th control point is set to U ⁰ _{i, k,} and the temperature difference in which the j-temperature control unit can adjust the temperature of the k-th control point at the i-th temperature control position with the largest change width is Δ. U _{i, k, j} , the operation amount when the operation amount of the jth temperature control unit with respect to the kth control point is 0, and the operation amount when the operation amount is maximized is 1. When the ratio is the operation ratio x _{k, j , the operation amount setting unit expresses the predicted temperature U i, k} at the i-th temperature control position of the k-th control point by the equation (1), and the predicted temperature. U _{i, k} is determined the optimum value of the operation ratio x _{k, j} using the mathematical programming method and inequality constraints that the temperature condition is satisfied, a plurality based the operation ratio x _k, the optimum value of the _j The operation amount of may be set.

According to the present invention, the temperature U ⁰ _{i, k at the k-th control point and the temperature difference ΔU i, k, j} that can adjust the temperature at the k-th control point with the largest change width are obtained in advance. Then, based on the temperature U ⁰ _{i, k of} the kth control point and the temperature difference ΔU _{i, k, j} , a mathematical programming method is used in which the predicted temperature U _{i, k} satisfies the temperature condition as an inequality constraint condition. The optimum value of the operation ratio x _{k, j is obtained by using.} As a result, the mathematical programming method can be solved as a linear problem rather than a non-linear problem, and a plurality of manipulated quantities can be easily set based on the optimum values of _{the manipulated ratios x k and j.}

Further, in the control device of the rolling mill, the objective function of the mathematical programming method or the inequality constraint condition evaluates the amount of temperature change at the plurality of temperature control positions with respect to the inlet side of the finish rolling mill at a plurality of control points. May include terms to be used.
According to the present invention, since the amount of temperature change at the plurality of temperature control positions with respect to the inlet side of the finishing rolling mill is evaluated, the temperature history of the control points is made substantially constant regardless of the position in the transfer direction, and the rolled material is conveyed. The shape change depending on the position in the direction can be reduced.

Further, in the control device of the rolling apparatus, the formula representing the inequality constraint condition further defines the relaxation amount with respect to the lower limit or the upper limit of the formula, and the objective function of the mathematical programming method is the relaxation amount and the relaxation amount. It may include a term having a weighting factor for balancing the quantities.
According to the present invention, not only when there is a solution of the operation ratio satisfying the inequality constraint, but also when there is no solution of the operation ratio satisfying the inequality constraint, the original inequality is used by using the relaxation amount and the weighting coefficient. It is possible to obtain a solution of the operation ratio that satisfies the relaxed inequality constraint while minimizing the deviation from the constraint.

According to the control device of the rolling apparatus, the control method of the rolling apparatus, and the control program of the rolling apparatus of the present invention, the quality of the rolled material can be further improved.

It is a schematic diagram for demonstrating the rolling apparatus controlled by the control apparatus of the rolling apparatus of one Embodiment of this invention. It is a figure which shows the outline of the control device of the rolling mill. It is a flowchart which shows the control method of the rolling apparatus in one Embodiment of this invention. It is a figure which shows the change of (A) rolling speed, (B) the temperature of a control point, (C) the temperature drop amount of a control point with respect to time about the simulation result of the control device of the comparative example. It is a figure which shows the change of (A) rolling speed, (B) the temperature of a control point, (C) the temperature drop amount of a control point with respect to time about the simulation result of the control apparatus of Example 1. FIG. It is a figure which shows the change of (A) rolling speed, (B) the temperature of a control point, (C) the temperature drop amount of a control point with respect to time about the simulation result of the control apparatus of Example 2. FIG.

Hereinafter, an embodiment of a control device for a rolling mill according to the present invention (hereinafter, simply referred to as a control device) will be described with reference to FIGS. 1 to 6.
FIG. 1 is a schematic view for explaining a rolling apparatus 100 controlled by a rolling apparatus control device (hereinafter, simply referred to as a control apparatus) 60 according to the present invention.
The rolling apparatus 100 is an apparatus for rolling the rolled material 1. The rolling apparatus 100 rolls the rolled material 1 on the transport path R formed in the rolling apparatus 100. The transport path R is a space formed in the rolling apparatus 100 for rolling while transporting the rolled material 1.
The rolling apparatus 100 includes a rough rolling mill 10, a finishing tandem rolling mill (finishing rolling mill) 20, a thermometer (temperature measuring unit) 15, a coarse bar heater 30 which is a plurality of temperature control units, and a rough bar cooling device 40. A cooling spray device 51 to 56 is provided.

The rough rolling mill 10 and the finishing tandem rolling mill 20 each roll the rolled material 1 on the transport path R.
The finishing tandem rolling mill 20 is arranged on the downstream side D2 in the transport direction D where the rolled material 1 is transported from the rough rolling mill 10. The rolled material 1 is roughly rolled by the rough rolling machine 10 to become a rolled material also called a rough bar. Subsequently, the rolled material 1 is finished rolled by the finishing tandem rolling mill 20.
The finishing tandem rolling mill 20 includes a plurality of stands (rolling mills) F1 to F7 (7 in this embodiment). The stands F1 to F7 are arranged in the order of the stand F1, the stand F2, ..., And the stand F7 from the upstream side D1 to the downstream side D2 in the transport direction D.
A plurality of control points (not shown) are set in the rolled material 1 at intervals in the transport direction D. It is preferable that the plurality of control points are set at a constant pitch from the front end to the rear end in the transport direction D of the rolled material 1. Of the plurality of control points, the k-th control point from the downstream side D2 in the transport direction D toward the upstream side D1 is referred to as a k-th control point. _{Let N k be} the number of a plurality of control points. In addition, k is an integer of _{1 or more and N k or less.}
The plurality of control points are preset by the user who uses the control device 60.

The thermometer 15 is arranged on the outlet side (downstream side D2) of the rough rolling mill 10. The thermometer 15 measures the temperatures of a plurality of control points of the rolled material 1 on the outlet side of the rough rolling mill 10. The thermometer 15 is arranged between the outlet of the rough rolling mill 10 on the transport path R and the rough bar heater 30 located at the most upstream of the plurality of temperature adjusting portions to measure the temperature of the rolled material 1. It suffices if it is configured as follows.
The thermometer 15 measures the temperature at each control point. The thermometer 15 gives the measured temperature to the control device 60.

The coarse bar heater 30, the coarse bar cooling device 40, and the cooling spray devices 51 to 56 adjust the temperature of the rolled material 1 at each installation position on the transport path R. The coarse bar heater 30 and the coarse bar cooling device 40 are arranged between the thermometer 15 and the inlet of the finishing tandem rolling mill 20. The coarse bar heater 30 is arranged on the upstream side D1 of the coarse bar cooling device 40.
The coarse bar heater 30 is a device that induces and heats the rolled material 1 by manipulating the electric power applied to the coiled winding. The coarse bar cooling device 40 and the cooling spray devices 51 to 56 are devices for cooling the rolled material 1 by adjusting the amount of cooling water by manipulating the valve opening degree.
The cooling spray devices 51 to 56 are arranged on the outlet sides of the stands F1 to F6, respectively. For example, the cooling spray device 51 is arranged between the stand F1 and the stand F2.

Hereinafter, among the plurality of temperature control units, the j-th temperature control unit from the upstream side D1 to the downstream side D2 in the transport direction D is also referred to as a j-th temperature control unit. _{Here, let} N j be the number of a plurality of temperature control units. In this example, the number N _j of the plurality of temperature adjustment portion is 8. j is an integer of 1 or more and 8 or less. Hereinafter, it is also described as “j = 1 to 8”.
For example, the first temperature control unit is a coarse bar heater 30, the third temperature control unit is a cooling spray device 51, and the eighth temperature control unit is a cooling spray device 56.
The method of ordering the plurality of temperature control units is not particularly limited.

A plurality of temperature control positions P are preset for the rolling apparatus 100. A plurality of temperature control positions P actually set in the present embodiment are indicated by filled circles and solid leader lines.
The plurality of temperature control positions P are preset by the user. In the present embodiment, since one temperature control position P is set in the finishing tandem rolling mill 20, the plurality of temperature control positions P are set on the transport path R in the finishing tandem rolling mill 20. The temperature control position P1 and the second temperature control position P2 set on the transport path R on the exit side of the finishing tandem rolling mill 20 are included. In the present embodiment, the number N _i of the plurality of temperature control position P, it is 2.
In the first temperature control position P1 and the second temperature control position P2, among the plurality of temperature control positions P, the i-th temperature control position P from the upstream side D1 to the downstream side D2 in the transport direction D is the i-th temperature control position. They are arranged side by side so as to be at the position Pi. In addition, i is an integer of 1 or more and 2 or less.
In the example of this embodiment, the first temperature control position P1 is set on the transport path R on the outlet side of the stand F3.

The number of temperature control positions P set in the finishing tandem rolling mill 20 is not particularly limited and may be 2 or more.
For example, although different from the present embodiment, a case where three temperature control positions P are set in the finishing tandem rolling mill 20 will be described. In this case, the first temperature control position P1 to the third temperature control position P3 are set from the upstream side D1 to the downstream side D2 on the transport path R in the finishing tandem rolling mill 20. A plurality of temperature control positions P set in the modified example are indicated by cross marks and dotted leader lines. The fourth temperature control position P4 is set on the transport path R on the exit side of the finishing tandem rolling mill 20. In this case, the number N _i of the plurality of temperature control position P, is 4.
The lower limit temperature and the upper limit temperature are predetermined for each temperature control position P. The lower limit temperature and the upper limit temperature for each temperature control position P are set in advance by the user.
Further, as will be described later, FIG. 1 shows a reference position P0 set on the transport path R on the inlet side of the finishing tandem rolling mill 20, unlike the temperature control position P.

FIG. 2 shows the control device 60 of this embodiment. The control device 60 controls the rolling device 100 to roll the rolled material 1. The control device 60 is a computer, and includes a CPU (Central Processing Unit) 61, a main storage device 62, an auxiliary storage device 63, an input / output interface (IO / I / F) 64, and a recording / playback device 65. I have. The CPU 61, the main storage device 62, the auxiliary storage device 63, the input / output interface 64, and the recording / playback device 65 are connected to each other by a bus 66.
The main storage device 62 is a RAM (Random Access Memory) or the like that serves as a work area or the like of the CPU 61.
The input / output interface 64 is connected to an input device 64a such as a keyboard and a mouse, and a display device 64b.
The recording / reproducing device 65 records and reproduces data on a recording medium 65a such as a USB (Universal Serial Bus) memory.

The auxiliary storage device 63 is a hard disk drive device or the like that stores various data, programs, and the like. The auxiliary storage device 63 stores a control program (hereinafter, simply referred to as a control program) 63a of the rolling apparatus for causing the computer to function as the control device 60, various programs such as an OS (Operating System) program, and the like. There is. Various programs including the control program 63a are taken into the auxiliary storage device 63 from the recording medium 65a via the recording / reproducing device 65. The control program 63a and the like are stored in the recording medium 65a.
These programs may be taken into the auxiliary storage device 63 from an external device via a disc-type recording medium such as a CD or DVD or a communication device (not shown).

The CPU 61 executes various arithmetic processes. The CPU 61 functionally includes a tracking unit 61a, a temperature acquisition unit 61b, an operation amount setting unit 61c, and an output unit 61d.
The tracking unit 61a, the temperature acquisition unit 61b, the operation amount setting unit 61c, and the output unit 61d, which are the functional components of the CPU 61, function by the CPU 61 executing the control program 63a and the like stored in the auxiliary storage device 63. .. The control program 63a and the like are programs for the control device 60. The control program 63a causes the control device 60 to function as a tracking unit 61a, a temperature acquisition unit 61b, an operation amount setting unit 61c, and an output unit 61d.

The tracking unit 61a tracks the positions of the plurality of control points of the rolled material 1 in the transport direction D. For example, a plate speed gauge (not shown) may be installed on each stand F1 to F7 inlet side. In this case, each plate speed meter measures the plate speed of the rolled material 1 at the installation position of the plate speed meter, and outputs the measured plate speed to the tracking unit 61a. The tracking unit 61a calculates the positions (tracking information) of the plurality of control points in the transport direction D based on the plate speed output from each plate speed meter.
The tracking unit 61a controls each kth using the rolling speed of the rough rolling mill 10, the rolling speed of the finishing tandem rolling mill 20, the feeding speed for transporting between the rough rolling mill 10 and the finishing tandem rolling mill 20, and the like. The position of the points may be tracked at predetermined time intervals.
The tracking unit 61a gives the calculated tracking information to the coarse bar heater 30, the coarse bar cooling device 40, and the cooling spray devices 51 to 56 at predetermined time intervals.
The temperature acquisition unit 61b is connected to the thermometer 15. The temperature acquisition unit 61b acquires the temperature of the rolled material 1 at the plurality of control points measured by the thermometer 15 from the thermometer 15, respectively.

The operation amount setting unit 61c satisfies the temperature condition that the temperature of each of the above control points is equal to or higher than the predetermined lower limit temperature and lower than the upper limit temperature for each of the plurality of temperature control positions P at each of the plurality of temperature control positions P. Set the operation amount of each temperature control unit. For example, the amount of operation is the electric power applied to the coarse bar heater 30, the valve opening degree of the coarse bar cooling device 40 and the cooling spray devices 51 to 56.
The operation amount setting unit 61c is based on the temperature of each control point given by the thermometer 15, the electric power of the coarse bar heater 30 for each control point, the valve opening degree of the coarse bar cooling device 40, and the cooling spray device 51 to 56. Calculate the valve opening of each.
The operation amount setting unit 61c gives the calculated electric power of the coarse bar heater 30, the valve opening degree of the coarse bar cooling device 40, and the valve opening degree of the cooling spray devices 51 to 56 to the output unit 61d.

The output unit 61d outputs each operation amount given by the operation amount setting unit 61c to the corresponding temperature adjusting units, that is, the coarse bar heater 30, the coarse bar cooling device 40, and the cooling spray devices 51 to 56, respectively.
The coarse bar heater 30 operates the electric power output by itself based on the operation amount of the electric power for each control point given by the output unit 61d and the tracking information given by the tracking unit 61a.
The coarse bar cooling device 40 operates its own valve opening based on the valve opening degree of the coarse bar cooling device 40 for each control point given by the output unit 61d and the tracking information given by the tracking unit 61a. ..
The cooling spray devices 51 to 56 have their own valve opening based on the valve opening of each cooling spray device 51 to 56 for each control point given by the output unit 61d and the tracking information given by the tracking unit 61a. To operate.
As described above, the temperature of the rolled material 1 is controlled.
The details of the control contents in the operation amount setting unit 61c will be described in detail in the following control method of the rolling mill (hereinafter, simply referred to as a control method).

Next, the control method of the present embodiment will be described. FIG. 3 is a flowchart showing the control method S of the present embodiment. In the control method S, the initial step S10, the temperature acquisition step S20, the operation amount setting step S30, and the output step S40 are performed.
First, in the initial step S10, the user determines the lower limit temperature and the upper limit temperature for each temperature control position P. The lower limit temperature and the upper limit temperature are determined for each rolled material 1 from the viewpoints of mechanical properties required for the rolled material 1, deterioration of surface properties, and prevention of scale defects.
When the restriction of the lower limit temperature is not necessary, the lower limit temperature may be reduced to, for example, 0 ° C. so that the restriction of the lower limit temperature can be satisfied without fail. When the upper limit temperature constraint is not required, the upper limit temperature may be increased to, for example, 2000 ° C. so that the upper limit temperature constraint can be satisfied without fail. Further, if it is desired to match the target temperature of a predetermined value as much as possible instead of the range having a constant temperature range of the lower limit temperature and the upper limit temperature, the target temperature may be given to the lower limit temperature and the upper limit temperature, respectively.
Further, in the initial step S10, the user sets a plurality of control points on the rolled material 1. The user sets the first temperature control position P1 and the second temperature control position P2 in the rolling apparatus 100.
With the above, the initial step S10 is completed, and the process proceeds to the temperature acquisition step S20.

Next, the temperature acquisition step S20 will be described.
When the k-th control point of the rolled material 1 reaches the measurement position of the thermometer 15, the thermometer 15 measures the temperature θ _k of the k-th control point of the rolled material 1. When the thermometer 15 starts measuring the temperature of the rolled material 1, k is 1. Thermometer 15 gives the temperature theta _k measured in the temperature acquiring unit 61b of the controller 60.
_{At this time, when the measured temperature θ k} is given to the temperature acquisition unit 61b after the sampling of the temperature measurement values of all the control points is completed, the tip of the rolled material 1 is the coarsest temperature control unit of the most upstream side D1. By the time the bar heater 30 is reached, the calculation to be described later performed by the operation amount setting unit 61c may not be in time. Therefore, after the temperature of the k-th control point is measured, the measured temperature of the k-th control point is given to the temperature acquisition unit 61b without waiting for the measurement of the temperature after the (k + 1) control point.
_{When the temperature θ k} measured from the thermometer 15 is given, the temperature acquisition unit 61b gives the temperature θ _k to the operation amount setting unit 61c.
With the above, the temperature acquisition step S20 is completed, and the process proceeds to the operation amount setting step S30.

Next, the operation amount setting step S30 will be described.
The operation amount setting unit 61c sets a plurality of operation amounts so as to satisfy the above temperature conditions. When there are a plurality of temperature control positions P and there are also a plurality of temperature control units for controlling their temperatures, a method of sequentially changing the operation amount of the temperature control units as described in Patent Document 1. In general, the temperature of the rolled material at the temperature control position P is difficult to predict because the change in the temperature of the rolled material with respect to the electric power and the valve opening is non-linear. Therefore, it is difficult to obtain the desired power and valve opening.
Therefore, a mathematical programming method is used in which the temperature condition is used as an inequality constraint. However, if the mathematical programming method is applied as a variable for solving the electric power and the valve opening, the relationship between the electric power and the valve opening and the temperature change is non-linear, which causes a non-linear programming problem. In this case, it is difficult to find the optimum solution by the time the control point to be calculated reaches the coarse bar heater 30.

Therefore, the temperature of the first temperature control position P1 and the temperature of the second temperature control position P2 are set to the reference temperature when the operation amount of each of the plurality of temperature control units is set to 0 (zero), and the operation of the plurality of temperature control units. It is expressed as the sum of the terms obtained by multiplying the maximum temperature changeable amount obtained when the amount is maximized individually by the operation ratio of the temperature control unit. Then, the mathematical programming method is applied as a variable for solving the operation ratio.
By doing so, the relationship between the operation ratio and the temperature change of the temperature control positions P1 and P2 becomes linear, so that the optimum value of the operation ratio can be obtained in a short time. Then, the operation amount of each temperature control unit is obtained from the optimum value of the operation ratio of each temperature control unit obtained as the optimum solution of the mathematical programming method.
Hereinafter, this calculation will be described in detail.

<Step S31: Calculation of reference temperature>
Based on the temperature theta k measured by the rough rolling machine 10 outlet side relative to the k control point, the temperature of the k-th control point in the i temperature control position when the plurality of temperature adjusting unit each operation amount set to 0 Calculate the reference temperature that is. When the operation amount of each of the plurality of temperature control units is set to 0, it means that the temperature control is not performed in all of the plurality of temperature control units.
Specifically, the reference temperature T 03 , k of the k-th control point at the first temperature control position P1 set on the transport path R on the outlet side of the stand F3 is predicted. Similarly, to predict the reference temperature T 0 7, k of the k-th control point at the second temperature management position P2 which is set on the conveying path R in the finishing tandem mill 20 outlet side. Further, although different from the temperature control position P, the reference position P0 is set on the transport path R on the inlet side of the finishing tandem rolling mill 20. Then, to predict the reference temperature T 0 0, k of the k-th control point in the reference position P0.
For this temperature calculation, for example, a known calculation method described in Japanese Patent Application Laid-Open No. 2008-22123 can be used.

Here, the reference temperature ^T _{0 3, k} for the first temperature control position P1 as a reference temperature ^U _{0 1, k,} and the reference temperature ^U _{0 2, k} a reference temperature ^T _{0 7, k} for the second temperature management position P2 do. At this time, the reference temperature (temperature) of the k-th control point at the i-th temperature control position when the operation amount of each of the plurality of temperature control units is 0 can be expressed as ^{U 0} _{i, k.}

<Step S32: Calculation of maximum temperature changeable amount>
The k on the basis of the temperature theta _k measured by the rough rolling machine 10 outlet to the control point, coarse bar heater power of 30 when maximizing the k finishing for the control point tandem mill 20 inlet side of the temperature, the stand The temperature on the outlet side of F3 and the temperature on the outlet side of the finishing tandem rolling mill 20 are predicted. And temperature expected, each of the reference temperature ^{_{T 0 0, k, T 0}} 3, k, T 0 7, the difference between _k, the maximum temperature changeable amount of coarse bar heater _{30 △ T 0, k, 1} , △ T _{Let it be 3, k, 1} , ΔT _{7, k, 1} . These values are positive because the coarse bar heater 30 is a heating device.
The maximum temperature changeable amounts ΔT _{3, k, 1} and ΔT _{7, k, 1} are such that the coarse bar heater 30, which is the first temperature control unit, is the kth at the first temperature control position P1 and the second temperature control position P2. The temperature difference at which the temperature of the control point can be adjusted with the largest change range. Since the coarse bar heater 30 is a heating device, the change width is a width that takes a positive value on the side that raises the temperature of the kth control point, and the temperature difference takes a positive value.
For the calculation of the temperature change by the coarse bar heater 30, for example, a known calculation method described in Patent Document 1 can be used.

Further, the temperature on the inlet side of the finishing tandem rolling mill 20, the temperature on the outlet side of the stand F3, and the temperature on the outlet side of the finishing tandem rolling mill 20 with respect to the kth control point when the valve opening degree of the rough bar cooling device 40 is maximized. Predict. The difference between the predicted temperature and the respective reference temperatures T ⁰ _{, k} , T ⁰ _{3, k} , T ⁰⁷ _{, k} is the maximum temperature changeable amount of the coarse bar cooling device 40 ΔT _{0, k, 2} , Let it be ΔT _{3, k, 2} , ΔT _{7, k, 2} . Since the coarse bar cooling device 40 is a cooling device, these values are negative.
The maximum temperature changeable amounts ΔT _{3, k, 2} and ΔT _{7, k, 2} are such that the coarse bar cooling device 40, which is the second temperature control unit, is at the first temperature control position P1 and the second temperature control position P2. It is a temperature difference that can adjust the temperature of the k-th control point with the largest change width. Since the coarse bar cooling device 40 is a cooling device, the change width is a width that takes a positive value on the side that lowers the temperature at the kth control point, and the temperature difference takes a negative value.

Similarly, the temperature on the inlet side of the finishing tandem rolling mill 20 with respect to the kth control point when the valve opening of the cooling spray device (50 + m) on the outlet side of the stand Fm is maximized, where m is an integer of 1 or more and 6 or less, and the stand. The temperature on the outlet side of F3 and the temperature on the outlet side of the finishing tandem rolling mill 20 are predicted. The difference between the predicted temperature and the respective reference temperatures T ⁰ _{, k} , T ⁰ _{3, k} , T ⁰⁷ _{, k} is the maximum temperature changeable amount of the cooling spray device (50 + m) ΔT _{0, k, ( Let m + 2)} , ΔT _{3, k, (m + 2)} , ΔT _{7, k, (m + 2)} . These values are negative because the cooling spray device (50 + m) is the cooling device.
The maximum temperature changeable amount ΔT _{3, k, (m + 2)} , ΔT _{7, k, (m + 2)} is that the cooling spray device (50 + m), which is the first (m + 2) temperature control unit, has the first temperature control position P1, It is a temperature difference that can adjust the temperature of the k-th control point at the second temperature control position P2 with the largest change width. Since the cooling spray device (50 + m) is a cooling device, the change width is a width that takes a positive value on the side that lowers the temperature at the kth control point, and the temperature difference takes a negative value.
For the calculation of the temperature change by the cooling device such as the coarse bar cooling device 40 and the cooling spray device 51 to 56, for example, a known calculation method described in Japanese Patent Application Laid-Open No. 2008-22142 can be used.

Here, the j-th temperature control unit sets the temperature of the k-th control point at the i-th temperature control position as ΔU _{i, k, j, which is a temperature difference that can be adjusted with the largest change width.} do.
The coarse bar heating device 30 is a first temperature control unit. Then, for the first temperature control position, ΔU _{1, k, 1} = ΔT _{3, k, 1} . For the second temperature control position, ΔU _{2, k, 1} = ΔT _{7, k, 1} .
The coarse bar cooling device 40 is a second temperature control unit. Then, for the first temperature control position, ΔU _{1, k, 2} = ΔT _{3, k, 2} . For the second temperature control position, ΔU _{2, k, 2} = ΔT _{7, k, 2} .
The cooling spray devices 51 to 56 are the third temperature control unit to the eighth temperature control unit. Then, for the first temperature control position, ΔU _{1, k, j} = ΔT _{3, k, (m + 2)} (j = m + 2). For the second temperature control position, ΔU _{2, k, j} = ΔT _{7, k, (m + 2)} (j = m + 2).
In addition, steps S31 and S32 may be performed in the initial step S10.

<Step S33: Solving the mathematical planning problem>
Here, the temperature at the inlet side of the finishing tandem rolling mill 20 at the kth control point is defined as the predicted temperature T0 _{, k} . The temperature at the first temperature control position P1 of the kth control point is defined as the predicted temperature T3 _{, k} . The temperature at the second temperature control position P2 of the kth control point is defined as the predicted temperature T7 _{, k} .
Using the values obtained in steps S31 and S32, the predicted temperatures T _{0, k} , T _{3, k} , T _{7, and k} are represented by equations (6) to (8), respectively.

However, x _{k and j} are operation ratios that are the ratio of the operation amount to the k control point when the operation amount of the j temperature control unit is 0 and when the operation amount is maximized. Is. In other words, the operation ratios x _{k and j} are the ratios at which the j-th temperature control unit is operated with respect to the k-th control point.
Equation (9) holds for the operating ratios x _{k and j of each temperature control device.} That is, the operation ratios x _{k and j} are ratios that take a value of 0 or more and 1 or less.

Although the temperature control position P is not on the inlet side of the finishing tandem rolling mill 20, it is calculated in order to obtain the change in the temperature history between the control points described later.
Here, it is assumed that the predicted temperature at the i-th temperature control position where the k-th control point is the i-th temperature control point is _{Ui, k} . At this time, U _{1, k} = T _{3, k} , U _{2, k} = T _{7, k , and the number N j} of the plurality of temperature control units is 8. Therefore, the predicted temperatures _{Ui and k} are expressed by Eq. (10).

Further, the temperature condition that the temperature of the kth control point at the temperature control position P is kept above the lower limit temperature and below the upper limit temperature can be expressed by the inequality constraint conditions of the equations (11) and (12).

Here, d ₃ and u ₃ are the lower limit temperature and the upper limit temperature at the first temperature control position P1. d ₇ and u ₇ are the lower limit temperature and the upper limit temperature at the second temperature control position P2.

If the temperature difference between the lower limit temperature and the upper limit temperature predetermined for each temperature control position P is larger than the capacity of the plurality of temperature control units, the inequality constraint conditions of equations (11) and (12) are applied. The set of operation ratios x _{k and j to be} satisfied is not limited to one set, and there may be a plurality of sets. In such a case, the optimum solution may be selected by setting the inequality constraint condition and the objective function in consideration of the viewpoints described below.

<First viewpoint>
The first aspect is to suppress the variation in the temperature history between the control points. Here, the temperature history refers to the temperature at the inlet side of the finishing tandem rolling mill 20, the temperature at the first temperature control position P1 which is the outlet side of the stand F3, and the temperature at the outlet side of the finishing tandem rolling mill 20 with respect to a certain control point. It means a temperature that changes depending on the temperature at a certain second temperature control position P2 and the position of a certain control point in the transport direction D.
In each of the stands F1 to F7 of the finishing tandem rolling mill 20, it is desirable that the change in the ratio of the rolling load during rolling is small. The reason for this is that the shape change between the control points of the rolled material 1 becomes small.
For this purpose, it is preferable that the change in the temperature history between the plurality of control points is small. Therefore, the difference between the temperature at the inlet side of the finishing tandem rolling mill 20 at the first control point and the temperature at the first temperature control position P1, the temperature at the inlet side of the finishing tandem rolling mill 20 at the first control point, and the first temperature. Consider equation (14), which is an inequality constraint that means that the difference from the temperature at the temperature control position P1 is _{within ± τ 03, k.}

Further, the difference between the temperature at the first temperature control position P1 of the k control point and the temperature at the second temperature control position P2, and the temperature and the second temperature control at the first temperature control position P1 of the first control point. Consider equation (15), which is an inequality constraint that means that the difference from the temperature at position P2 is _{within ± τ 37, k.}

Similarly, the difference between the temperature at the finishing tandem rolling mill 20 inlet side at the k control point and the temperature at the second temperature control position P2, and the temperature at the finishing tandem rolling mill 20 inlet side at the first control point and the first 2 Consider Eq. (16), which is an inequality constraint that means that the difference from the temperature at the temperature control position P2 is _{within ± τ07, k.}

_{Then, J τ, k of} Eq. (19) is mathematically planned so that the sum of the upper and lower limit values τ _{03, k} , τ _{37, k} , τ _{07, k of Eqs. (14) to (16) becomes smaller.} It is preferable that it is one term of the objective function in.

However, w _τ is a positive weighting factor.
That is, the objective function of the actuarial programming method is the amount of temperature change at the first temperature control position P1 with respect to the finish rolling mill 10 inlet side and the second temperature control position P2 with respect to the finish rolling mill 10 inlet side at a plurality of control points. Includes the term by _{J τ, k in} Eq. (19), which evaluates the amount of temperature change in.
_{By setting a plurality of manipulated variables so as to minimize J τ, k of} Eq. (19) included in the objective function, the temperature history of the k-th control point and the temperature history of the first control point can be brought close to each other. can. As a result, the shape change between the control points of the rolled material 1 can be reduced.
In the equations (14) to (16), the upper and lower limits of the difference in temperature change between the kth control point and the first control point are set as inequality constraints. However, for example, the upper and lower limits of the difference in temperature change between the k-th control point and the (k-1) control point may be set as an inequality constraint condition.
Further, in the equation (19), J _{τ, k} is a weighted linear sum of the upper and lower limit values τ _{03, k} , τ _{37, k} , τ _{07, k , but J τ, k} is the upper and lower limit values τ _{03, It} may be a weighted square sum of k, τ _{37, k} , τ _{07, k.} The inequality constraint condition of the mathematical programming method may include a term for evaluating the amount of temperature change at a plurality of temperature control positions P with respect to the inlet side of the finish rolling mill 10 at a plurality of control points.

<Second viewpoint>
The second viewpoint is to suppress the amount of operation of each temperature control unit. The smaller the amount of operation of each temperature control unit, the lower the manufacturing cost of the rolled material 1. Therefore, the equation (20) is used so that the coarse bar heater 30 which is a heating device does not heat more than necessary and the coarse bar cooling device 40 and the cooling spray device 51 to 56 which are cooling devices do not cool more than necessary. _{It is preferable that JT and k of} are one term of the objective function.

On the right side of the equation (20), the first term is a term for suppressing the amount of heat generated by the coarse bar heater 30. The second term, the cooling device group (crude bar cooling device 40 and a cooling spray devices 51 to 56) predicted temperature T _{7, k} is low the operation amount of the k-th control point at the second temperature management position P2 too large It is a term to prevent it from becoming too much. w _x1 and w _T7 are positive weighting coefficients, respectively. _{By reducing JT and k in} Eq. (20), the amount of operation of each temperature control unit can be suppressed.

<Third viewpoint>
The third aspect is the priority of use of a plurality of cooling devices included in the cooling device group. When the temperature of the rolled material 1 changes, the thicker the plate, the less likely the shape of the rolled material 1 changes. Therefore, it is desirable to use the cooling device from the cooling device arranged on the upstream side D1 in the transport direction D. Therefore, in order to preferentially use the cooling device arranged on the upstream side D1 of the coarse bar cooling device 40 and the cooling spray devices 51 to 56, J _{x and k in the} equation (21) are set as one term of the objective function. Is preferable.

However, w _j is a positive weighting coefficient, and w _j is in ascending order with _{respect to the subscript j (w 1} <w ₂ << w ₈ ). _{By reducing the J x and k of the} equation (21), it is possible to preferentially use the cooling device arranged on the upstream side D1 and make it difficult for the shape change of the rolled material 1 to occur.

The above description is for selecting a more desirable set when there are a plurality of sets of _{operation ratios x k, j} (j = 1 to 8) satisfying the inequality constraint of Eqs. (11) and (12). The method.
On the contrary, when the temperature difference between the lower limit temperature and the upper limit temperature predetermined for each temperature control position P is smaller than the capacity of the plurality of temperature control units, each of them depends _{on the temperature θ k on the outlet side of the rough rolling mill 10.} No matter how the temperature control unit is used, the inequality constraint of Eq. (11) or Eq. (12) may not be satisfied. In such a case, it is desirable to control so that the amount of temperature deviation from the inequality constraint of Eq. (11) or (12) is as small as possible.
Therefore, the formula representing the inequality constraint condition defines the amount of relaxation for the lower limit temperature (lower limit) or upper limit temperature (upper limit) of the formula. Then, it is desirable that the objective function of the mathematical programming method includes a term having a relaxation amount and a weighting coefficient for balancing the relaxation amount. For example, the lower limit temperature _{d 3,} and relaxation amounts [delta] _{3, k} of the upper limit temperature _{u 3,} the lower limit temperature _{d 7,} defines a relaxation amount [delta] _{7, k} of the upper limit temperature _{u 7,} an inequality constraint expression (11) The equation (24) is changed to the equation (24), and the equation (12) is changed to the equation (25).

_{Then, it is preferable that J δ, k} represented by Eq. (26), which is a weighted linear sum of the relaxation amount δ _{3, k} and the relaxation amount δ _{7, k} , is one term of the objective function.

_Here, w δ3, w δ7 is relaxed amount [delta] _{3, k,} a positive weight coefficient for balancing the [delta] _{7, k.} It is preferable that the weighting coefficients w _δ3 and w _{δ7 are set sufficiently large.}
As a result, when there is a solution of the _{operation ratio x k, j that} satisfies the inequality constraint of Eqs. (11) and (12) _{, J δ, k} = 0, that is, δ _{3, k} = δ _{7, k.} A solution with = 0 can be obtained, and a solution with operation ratios x _{k and j} satisfying the inequality constraints of Eqs. (11) and (12) can be obtained.
If there is no solution of the _{operation ratio x k, j that} satisfies the inequality constraint of Eqs. (11) and (12), the temperature deviates under the index represented by _{J δ, k of Eq. (26).} The inequality constraints of Eqs. (11) and (12) are relaxed by the amount that minimizes the quantity, and a solution satisfying the relaxed inequality constraints of Eqs. (24) and (25) can be obtained.
The term to be added to the objective function may be a term that applies a penalty as in Eq. (26) to the magnitude of the relaxation amount. Therefore, (26) J _[delta] as _type, alleviating amount _k [delta] _{3, k,} instead of the weighted linear sum of _{δ 7, k, J δ,} k relief amount [delta] _{3, k,} [delta] _{7 , K} may be a weighted sum of squares.

Summarizing the above, the inequality constraints of the mathematical programming problem (mathematical programming method) are equations (9), (14) to (16), (24), and (25). This inequality constraint condition is a modified temperature condition in which the conditions of the equations (9), (14) to (16) are added to the equations (24) and (25) in which the temperature condition is relaxed.
In step S33, the operation amount setting unit 61c uses _{the mathematical programming method in which the predicted temperature T3, k} , T7 _{, and k} satisfy the correction temperature condition as an inequality constraint, and the equations (19) to (21) are used. , And the optimum solution (optimal value) x _{opt, k, j} of _{the operation ratio x k, j} of each temperature control unit that minimizes the objective function of the formula (27) represented by the sum of the formulas (26).

The predicted temperature T _{3, k} is the same value as the predicted temperature U _{1, k} , and the predicted temperature T _{7, k} is the same value as the predicted temperature U _{2, k.} Therefore, the above procedure for obtaining the optimum solution (optimum value) x _{opt, k, j} of the operation ratio x _{k, j is the predicted temperature U i, for the predicted temperature U i, k} represented by the equation (10) _{. Using a mathematical programming method with k} satisfying the modified temperature condition as an inequality constraint, the optimum solution x _{opt, k of the operating ratio x k, j} of each temperature control unit that minimizes the objective function of Eq. (27) It is the same as _{finding ， j.}

<Step S34: Obtaining the amount of operation of each temperature control unit>
_{The temperature change of the rolled material 1 with respect to the electric power z 1} applied to the coarse bar heater 30 can be expressed by the relationship as described in Patent Document 1, for example. Therefore, the temperature change of the rolled material 1 can be expressed as _{, for example, a function f 1} (z _1). Here, assuming that the maximum power that can be applied to the coarse bar heater 30 is z _1max , the optimum solution x _{opt, k, 1} of _{the operation ratio x k, 1} of the coarse bar heater 30 obtained by solving the mathematical planning problem in step S33 is obtained. The electric power z _{k, 1} (operation amount) to be satisfied is expressed by Eq. (30).
Operation amount setting section 61c is (30) by solving the equation, operating ratio _{x k, 1} of the optimal solution _{x opt,} based on _{k, 1,} power _{z k, 1} to be applied to the coarse bar heater 30 for the k control point To set.

_{Further, the temperature change of the rolled material 1 with respect to the valve opening degree z 2} of the coarse bar cooling device 40 can be expressed by the relationship described in, for example, Japanese Patent Application Laid-Open No. 2008-22123. The temperature change of the rolled material 1 can be expressed as _{, for example, a function f 2} (z _{2).
Here, assuming} that the maximum valve opening degree of the coarse bar cooling device 40 is z 2max, the valve opening that satisfies _{the optimum solution x opt, k, 2} of the operating ratio of the rough bar cooling device 40 obtained by solving the mathematical programming method. Degree z _{k, 2} (operation amount) is expressed by Eq. (31).
The operation amount setting unit 61c solves the equation (31), and based on the optimum solution x _{opt, k, 2 of the operation ratio x k, 2 , the valve opening z k} of the coarse bar cooling device 40 with respect to the kth control point. _{, 2} are set.

Similarly, the temperature change of the rolled material 1 with respect to _{the valve opening z (m + 2)} of the cooling spray device (50 + m) on the stand Fm outlet side (m = 1 to 6) _{is expressed as a function f (m + 2)} (z _{(m + 2)} ). Can be represented. Here, assuming that the maximum valve opening of the cooling spray device (50 + m) is z _{(m + 2) max} , the optimum solution of the operating ratio of the cooling spray device (50 + m) obtained by solving the mathematical programming method x _{opt, k, The} valve opening z _{k, (m + 2)} (operation amount) satisfying (m + 2) is expressed by the equation (32).
The operation amount setting unit 61c solves the equation (32), and based on the optimum solution x _{opt, k, (m + 2) of the operation ratio x k, (m + 2)} , of the cooling spray device (50 + m) with respect to the k control point. Set the valve opening z _{k, (m + 2)} .

The operation amount setting unit 61c has the electric power z _{k, 1 applied to the coarse bar heater 30 set as described above, the valve opening z k, 2 of} the coarse bar cooling device 40, and the valve opening of the cooling spray device (50 + m). z _{k, (m + 2)} is given to the output unit 61d.
With the above, the operation amount setting step S30 is completed, and the process proceeds to the output step S40.

In the output step S40, the output unit 61d outputs the electric power z _{k, 1} and the valve opening z _{k, 2} , z _{k, (m + 2)} to the corresponding temperature control units, respectively.
_{Specifically, the electric power z k, 1} applied to the coarse bar heater 30 with respect to the kth control point is given to the coarse bar heater 30 corresponding to the electric power z _{k, 1.} Similarly, providing the valve opening z _{k, 2} coarse bars cooling device 40 for the k control point, the valve opening z _{k, 2} corresponding to the coarse bar cooling device 40. Valve opening _{z k} of the cooling spray device relative to the k control points _{(50 + m), (m} + 2) and the valve opening _{z k,} gives respectively _{(m + 2)} corresponding to the cooling spray device (50 + m).
With the above, the output step S40 is completed, and the process proceeds to step S50.

In step S50, _{it is determined whether or not the temperature of the Nk} control point (control point located at the rear end of the rolled material 1) has been measured. When the _{temperature of the Nkth} control point is measured, all the steps of the control method S are completed.
On the other hand, if No is determined in step S50, the temperature acquisition step S20, the operation amount setting step S30, and the output step S40 are performed again. When the temperature acquisition step S20 is performed again, the temperature θ _{(k + 1)} at the first (k + 1) control point of the rolled material 1 is measured by the thermometer 15.
The temperature acquisition step S20, the operation amount setting step S30, and the output step S40 are combined and repeated until it is determined to be Yes in step S50.

As described above, according to the control device 60, the control method S, and the control program 63a of the present embodiment, a plurality of control points set in the rolled material 1 by the temperature acquisition unit 61b (in the temperature acquisition step S20). The temperature of the rolled material 1 in the above is obtained from the thermometer 15. By the operation amount setting unit 61c (in the operation amount setting step S30), the temperatures of the plurality of control points at each of the plurality of preset temperature control positions P are equal to or higher than the preset lower limit temperature and the upper limit for each temperature control position P. Set a plurality of operation amounts so as to satisfy the temperature condition within the temperature. Then, each operation amount set by the output unit 61d (in the output process S40) and by the operation amount setting unit 61c (in the operation amount setting process S30) is output to the corresponding temperature control unit.

When the coarse bar heater 30 receives the tracking information that the kth control point has reached the control position of the coarse bar heater 30, the power of the coarse bar heater 30 is set to the electric power z _{k, 1} . Similarly, when the coarse bar cooling device 40 receives the tracking information that the kth control point has reached the control position of the coarse bar cooling device 40, the valve opening degree of the coarse bar cooling device 40 is changed to the valve opening z _{k. , 2} . When the cooling spray device (50 + m) receives the tracking information that the kth control point has reached the control position of the cooling spray device (50 + m), the valve opening of the cooling spray device (50 + m) is changed to the valve opening z _{k, ( Let it be m + 2)} .
By the above steps, the rolled material 1 is rolled while the temperature of the rolled material 1 is controlled.

At this time, the plurality of temperature control positions P are not only the second temperature control position P2 set on the transport path R on the outlet side of the finish rolling mill 20 which is a position outside the finish rolling mill 20, but also inside the finish rolling mill. Includes the first temperature control position P1 set on the transport path R in the finish rolling mill 20, which is the position. Therefore, the temperatures of the plurality of control points are predetermined for each temperature control position P not only at the second temperature control position P2 outside the finish rolling mill 20 but also at the first temperature control position P1 inside the finish rolling mill 20. It falls below the lower limit temperature and below the upper limit temperature. Therefore, since the temperatures of the plurality of control points of the rolled material 1 are further stabilized, the quality of the rolled material 1 can be further improved.

_{The manipulated variable setting unit 61c expresses the predicted temperatures U i and k} at the i-th temperature control position where the k-th control point is expressed by the equation (10). The predicted temperature U _{i, k} is used mathematical programming method that was inequality constraints that fix temperature satisfying operation ratio x _k, determine the optimum value of _j, based on the optimum value of the operation ratio x _{k, j} Set multiple operation amounts.
At this time, the temperature U ⁰ _{i, k of} the kth control point and the maximum temperature changeable amount ΔU _{i, k, j} are obtained. Then, based on the temperature U ⁰ _{i, k} and the maximum temperature changeable amount ΔU _{i, k, j} , a mathematical programming method is used in which the predicted temperature U _{i, k} satisfies the modified temperature condition as an inequality constraint condition. To find the optimum value of the operation ratio x _{k, j.} As a result, the mathematical programming method can be solved as a linear problem rather than a non-linear problem, and a plurality of manipulated quantities can be easily set based on the optimum values of _{the manipulated ratios x k and j.}
Since it is easy to calculate a plurality of operation amounts, it is possible to set a plurality of operation amounts in a short time.

Although one embodiment of the present invention has been described in detail with reference to the drawings, the specific configuration is not limited to this embodiment, and the configuration is changed, combined, or deleted without departing from the gist of the present invention. Etc. are also included.
For example, in the above-described embodiment, a part of the four terms on the right side of the equation (27) may be used as the right side of the equation (27).
Further, the predicted temperature _{U i,} in place of the _k that modifications temperature condition is satisfied, the predicted temperature _{U i, k} may fulfill the temperature condition is (11) and (12). In this case, the temperature condition matches the inequality constraint. _{Then, the manipulated variable setting unit 61c uses a mathematical programming method with the inequality constraint condition that the predicted temperatures Ui and k} satisfy the temperature condition, and the operation amount setting unit 61c of each temperature control unit that minimizes the objective function of the equation (27). Find the optimal solution x _{opt, k, j} of the operation ratio x _{k, j.}

The configuration and arrangement of the plurality of temperature control units are not particularly limited.
The number of stands included in the finishing tandem rolling mill 20 is not particularly limited.
The operation amount setting unit 61c may set a plurality of operation amounts by using a method other than the mathematical programming method.

(Example)
Hereinafter, examples and comparative examples of the present invention will be specifically shown and described in more detail, but the present invention is not limited to the following examples.
Hereinafter, the results of simulating the above-described embodiment and the like using a computer will be described. _{In both the comparative example and the embodiment, the lower limit temperature d 3} at the first temperature control position P1 on the outlet side of the stand F3 was set to 0 ° C., and the upper limit temperature u ₃ was set to 925 ° C. _{The lower limit temperature d 7} at the second temperature control position P2 on the outlet side of the finishing tandem rolling mill 20 was set to 860 ° C., and the upper limit temperature u ₇ was set to 900 ° C. The pitch of the transport direction D between the plurality of control points was set to 0.5 m.

(A) to (C) of FIG. 4 show the conditions and results of the simulation of the control device of the comparative example. Similarly, FIGS. 5A to 5C show the conditions and results of the simulation of the control device of the first embodiment. 6 (A) to 6 (C) show the conditions and results of the simulation of the control device of the second embodiment.
In any of FIGS. 4 to 6, the horizontal axis represents the distance from the tip of the rolled material 1 to the control point in the rough bar state.
The vertical axis of (A) represents the rolling speed of the finishing tandem rolling mill 20 when the control point passes through the stand F7. The vertical axis of (B) represents the temperature of the control point. The vertical axis of (C) represents the amount of temperature drop at the control point.

The thin solid line L2 in (B) represents the temperature of the control point of the rolled material 1 which became a rough bar on the outlet side of the rough rolling mill 10. The dotted line L3 in (B) represents the temperature of the control point at the first temperature control position P1 on the exit side of the stand F3. The thick solid line L4 in (B) represents the temperature of the control point at the second temperature control position P2 on the exit side of the finishing tandem rolling mill 20.
The dotted line L5 in (C) represents the amount of drop between the temperature at the inlet side of the finishing tandem rolling mill 20 at the control point and the temperature at the first temperature control position P1. The thick solid line L6 in (C) represents the amount of drop between the temperature at the first temperature control position P1 and the temperature at the second temperature control position P2 of the control point. The thin solid line L7 in (C) represents the amount of drop between the temperature at the inlet side of the finishing tandem rolling mill 20 at the control point and the temperature at the second temperature control position P2.

In the control devices of Comparative Examples and Examples, the temperatures at the outlets of the rough rolling mill 10 at each control point were given as shown by line L2 in (B) of FIGS. 4 to 6. Further, the rolling speed of the finishing tandem rolling mill 20 when each control point passes through the stand F7 has a pattern of accelerating from the middle of rolling and becoming constant as shown in line L1 of FIGS. 4 to 6 (A). ..

First, FIG. 4 shows a simulation result when the temperature control position P is only the second temperature control position P2 as the control device of the comparative example which is the conventional method. In this example, when solving the mathematical programming problem in step S33 described above, equations (24) relating to the first temperature control position P1 and equations (14) to (16) relating to changes in the temperature history between control points are inequality. Removed from constraints. _{Correspondingly, J δ, k of} Eq. (26), which is one term (4th term) of Eq. (27), which is the objective function, is changed to Eq. (35), and it is the objective function (27). The calculation is performed by deleting the terms _{J τ and k in} Eq. (19) from the right side of Eq.

In the control device of the comparative example, the temperature of the rolling material 1 in the second temperature management position P2 shown by a line L4 of (B), the lower limit temperature d ₇ than the upper limit temperature u ₇ following range at a second temperature control position P2 It is almost within the range of 860 to 900 ° C.
On the other hand, the temperature of the rolling material 1 in the first temperature control position P1 indicated by the line L3 is higher than 925 ° C. of maximum temperature u ₃ at the first temperature control position P1.

Next, FIG. 5 shows a simulation result when the temperature control position P is set to two points, the first temperature control position P1 and the second temperature control position P2, as the control device of the first embodiment. This removes equations (14) to (16) relating to changes in the temperature history between control points from the inequality constraints when solving the mathematical programming problem in step S33 described above. _{Correspondingly, the terms of J τ and k in} Eq. (19) are deleted from Eq. (27), which is the objective function, and the calculation is performed. That is, for the control device of the comparative example, equation (24) relating to the first temperature control position P1 is added to the inequality constraint condition, and J _{δ and k,} which are one term of the objective function, are equations (35) to (26). Has been changed to.

In the control device of Example 1, the temperature of the rolled material 1 in the second temperature management position P2 shown by a line L4 in FIG. 5 (B), the lower limit temperature d ₇ than the upper limit temperature u at the second temperature management position P2 It is almost within the range of 860 to 900 ° C., which is a range of _{7 or less.} Then, the temperature of the rolling material 1 in the first temperature control position P1 indicated by the line L3 is between from 0 to 925 ° C., which is the upper limit temperature u ₃ below lower range limit temperature d ₃ or more at a first temperature control position P1 It fits.
Temperature of the rolled material 1 in the second temperature management position P2 indicated by the line L4 at a location near 30m from the tip of the strip 1 has slightly exceeded 900 ° C. maximum temperature u _7. In this vicinity, the valve openings of all the cooling devices are fully opened, resulting in insufficient cooling control capacity. Even in such a case, the lower limit temperature d _7, defining the relaxation amount [delta] _{7, k} for the upper limit temperature u ₇ (25) below the formula which represents the inequality constraints, as one of the objective function (27) (26 ) Add the term (w _{δ7 δ7 , k) in the equation.} As a result, the amount of temperature deviation from the inequality constraint of Eq. (12) can be controlled to be as small as possible.

In the control device of the second embodiment, the temperature control position P is set to two points, the first temperature control position P1 and the second temperature control position P, as in the control device of the first embodiment. Furthermore, the term for evaluating the change in temperature history between control points is included in the objective function and the inequality constraint. The simulation result in this case is shown in FIG. This is the result of calculation according to the procedure for solving the mathematical programming problem in step S33 described above. In the control device of the second embodiment, the inequalities (14) to (16) relating to the change in the temperature history between the control points are added to the inequality constraint conditions for the control device of the first embodiment, and (19) is added to the objective function. ) _{The terms J τ and k} are added.

In the control device of the second embodiment, similarly to the control device of the first embodiment, the temperature of the rolled material 1 at the second temperature control position P2 shown by the line L4 of FIG. 6B is the second temperature control position P2. and substantially it falls between 860-900 ° C. which is the lower limit temperature _{d 7} than the upper limit temperature _{u 7} following range at. Then, the temperature of the rolling material 1 in the first temperature control position P1 indicated by the line L3 is between 0 to 925 ° C., which is the upper limit temperature u ₃ below lower range limit temperature d ₃ or more at a first temperature control position P1 It fits.
Further, the amount of temperature deviation when the cooling control capacity is insufficient at a position of about 30 m from the tip of the rolled material 1 can be controlled to be as small as possible. Further, in the control device of the second embodiment, the temperature drop amount of the control points shown by the lines L5 to L7 in (C) is smaller than the temperature drop amount of the control device of the first embodiment. In the control device of the second embodiment, the variation in the temperature history between the control points is suppressed as compared with the control device of the first embodiment.

1 Rolled material 10 Rough rolling mill 15 Thermometer (Temperature measuring unit)
20 Finishing tandem rolling mill (finishing rolling mill)
30 Coarse bar heater (temperature control unit)
40 Coarse bar cooling device (temperature control unit)
51, 52, 53, 54, 55, 56 Cooling spray device (temperature control unit)
60 Control device (Rolling device control device)
61b Temperature acquisition unit 61c Operation amount setting unit 61d Output unit 63a Control program (rolling equipment control program)
100 Rolling equipment D Transport direction P Temperature control position P1 First temperature control position (Temperature control position)
P2 2nd temperature control position (temperature control position)
R Transport path S Control method (Rolling equipment control method)
S20 Temperature acquisition process S30 Operation amount setting process S40 Output process

Claims (6)

A rough rolling machine and a finishing rolling machine that roll rolled materials on a transport path,
A temperature measuring unit that measures the temperature of the rolled material between the outlet of the rough rolling mill and the inlet of the finishing rolling mill on the transport path.
A plurality of temperature control units for adjusting the temperature of the rolled material between the temperature measurement unit and the finish rolling mill outlet on the transport path, and a plurality of temperature control units.
A control device for a rolling apparatus for rolling a rolled material by controlling a rolling apparatus provided with the above.
A temperature acquisition unit that acquires the temperature of the rolled material from the temperature measuring unit at a plurality of control points set for the rolled material at intervals in the transport direction in which the rolled material is conveyed.
At each of the plurality of preset temperature control positions, the plurality of control points satisfy the temperature condition that the temperature of the plurality of control points is equal to or higher than the predetermined lower limit temperature and lower than the upper limit temperature for each of the plurality of temperature control positions. The operation amount setting unit that sets the operation amount of each temperature control unit, and the operation amount setting unit
An output unit that outputs each of the operation amounts set by the operation amount setting unit to the corresponding temperature control units, and an output unit.
With
The plurality of temperature control positions are control devices of the rolling apparatus including a temperature control position set on the transport path on the outlet side of the finish rolling mill and a temperature control position set on the transport path in the finish rolling mill. .. _{Let Nj} be the number of the plurality of temperature control units.
Of the plurality of control points, the kth control point from the downstream side to the upstream side in the transport direction is set as the kth control point.
Of the plurality of temperature control positions, the i-th temperature control position from the upstream side to the downstream side in the transport direction is set as the i-th temperature control position.
Of the plurality of temperature control units, the j-th temperature control unit from the upstream side to the downstream side in the transport direction is designated as the j-th temperature control unit.
When the manipulated variable of each of the plurality of temperature control units is set to 0, the temperature of the kth control point at the i-th temperature control position is set to U ⁰ _{i, k} .
The temperature difference at which the j-th temperature control unit can adjust the temperature of the k-th control point at the i-th temperature control position with the largest change width is ΔU _{i, k, j} .
The ratio of the manipulated variable to the k-th control point is 0 when the manipulated variable of the j-th temperature control unit is 0, and 1 when the manipulated variable is maximized, which is the manipulated variable x _{k, j.} When
The operation amount setting unit is
_{The predicted temperatures Ui and k} at the i-th temperature control position of the k-th control point are expressed by Eq. (1).
The optimum value of the _{operation ratio x k, j} was obtained by using a mathematical programming method with the predicted temperature U _{i, k} satisfying the temperature condition as an inequality constraint condition.
The control device for a rolling apparatus according to claim 1, wherein a plurality of operation amounts are set based on the optimum values of the operation ratios x _{k and j.}

The objective function of the mathematical programming method or the inequality constraint condition according to claim 2, further comprising a term for evaluating the amount of temperature change at the plurality of temperature control positions with respect to the inlet side of the finish rolling mill at a plurality of control points. Rolling equipment control device. The formula representing the inequality constraint further defines the amount of relaxation for the lower or upper limit of the formula.
The control device for a rolling apparatus according to claim 2 or 3, wherein the objective function of the actuarial programming method includes a term having the relaxation amount and a weighting coefficient for balancing the relaxation amount. A rough rolling machine and a finishing rolling machine that roll rolled materials on a transport path,
A temperature measuring unit for measuring the temperature of the rolled material at a portion between the rough rolling mill outlet and the finishing rolling mill inlet on the transport path.
A plurality of temperature control units for adjusting the temperature of the rolled material in a portion between the temperature measuring unit on the transport path and the outlet of the finishing rolling mill, and a plurality of temperature control units.
A method for controlling a rolling apparatus for rolling a rolled material by controlling a rolling apparatus comprising the above.
A temperature acquisition step of acquiring the temperature of the rolled material from the temperature measuring unit at a plurality of control points set for the rolled material at intervals in the transport direction in which the rolled material is conveyed.
The plurality of temperatures so that the temperatures of the plurality of control points at each of the plurality of preset temperature control positions satisfy the temperature condition within the predetermined lower limit temperature or higher and the upper limit temperature or lower for each of the temperature control positions. The operation amount setting process that sets the operation amount of each adjustment unit,
An output step of outputting each of the manipulated variables set by the manipulated variable setting step to the corresponding plurality of temperature control units, respectively.
And
The plurality of temperature control positions include a temperature control position set on the transport path on the outlet side of the finish rolling mill and a temperature control position set on the transport path in the finish rolling mill. .. A rough rolling machine and a finishing rolling machine that roll rolled materials on a transport path,
A temperature measuring unit for measuring the temperature of the rolled material at a portion between the rough rolling mill outlet and the finishing rolling mill inlet on the transport path.
A plurality of temperature control units for adjusting the temperature of the rolled material in a portion between the temperature measuring unit on the transport path and the outlet of the finishing rolling mill, and a plurality of temperature control units.
It is a control program of a rolling apparatus for a control apparatus which controls a rolling apparatus provided with, and rolls the rolled material.
The control device
A temperature acquisition unit that acquires the temperature of the rolled material from the temperature measuring unit at a plurality of control points set for the rolled material at intervals in the transport direction in which the rolled material is conveyed.
The plurality of temperatures so that the temperatures of the plurality of control points at each of the plurality of preset temperature control positions satisfy the temperature condition within the predetermined lower limit temperature or higher and the upper limit temperature or lower for each of the temperature control positions. The operation amount setting unit that sets the operation amount of each adjustment unit, and the operation amount setting unit
An output unit that outputs each of the operation amounts set by the operation amount setting unit to the corresponding temperature control units, and an output unit.
To make it work
The plurality of temperature control positions are control programs of a rolling apparatus including a temperature control position set on the transport path on the outlet side of the finish rolling mill and a temperature control position set on the transport path in the finish rolling mill. ..

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