JPH0966310A - Thickness control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thickness control device capable of obtaining a proportional control gain as much as possible in response to external disturbance. SOLUTION: An arithmetic part 41 of a gain deciding part 4 reads in a pertinent integral control gain and proportional control gain from a gain table 42 based on the given material information. The arithmetic part 41 stores the deviation pattern of material S to be rolled in a deviation pattern storage part 44. Further, the arithmetic part 41 selects a deviation pattern similar to the deviation pattern stored in the deviation pattern storage part 44 from a gain correcting table 43 and reads in the integral control gain corrected value and proportional control gain corrected value registered in the selected deviation pattern. The arithmetic part 41 obtains the corrected integral control gain and corrected proportional gain by multiplying the integral control gain/ proportional control gain to the integral control gain corrected value/ proportional control gain corrected value, these are given to integral arithmetic part 5 or proportional arithmetic part 6, the plate thickness control in rolling of other material S to be rolled having the same material/dimension in the same lot is executed.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a thickness control device for controlling the thickness of a material to be rolled rolled by a rolling mill.

[0002]

2. Description of the Related Art FIG. 7 is a block diagram showing a conventional thickness control device, in which S is a material to be rolled such as a steel plate. In the figure,
A four-roll type rolling mill 1 including work rolls 11 and 11 and backup rolls 12 sandwiching the work rolls 11 and 11 is arranged in the transfer area of the material S to be rolled in the arrow direction. is there. The work rolls 11 and 11 and the backup rolls 12 and 12 are driven by an actuator 9, and the work rolls 11 and 11 and the backup rolls 12 and 12 driven by the actuator 9 have rolling positions and rolling loads. Are controlled by the drive controller 8.

A thickness gauge 2 for detecting the thickness of the material S to be rolled is arranged on the exit side of the rolling mill 1, and the detection result of the thickness gauge 2 is given to the deviation calculator 20. The deviation calculating unit 20 includes the rolled material S
The target plate thickness is also given, and the deviation calculation unit 20 subtracts the detected plate thickness from the target plate thickness to obtain a plate thickness deviation, and supplies it to the integral calculation unit 15 and the proportional calculation unit 16, respectively. An integral control gain and a proportional control gain are preset in the integral calculation section 15 and the proportional calculation section 16, respectively.
Further, the proportional calculation unit 16 multiplies the result of the integral calculation and the proportional calculation of the plate thickness deviation by the integral control gain and the proportional control gain in order to remove the plate thickness deviation, and gives them to the addition unit 17, respectively. The adder unit 17 adds both calculation results and gives them to the drive control device 8.

However, the thickness control device for performing such proportional-plus-integral control has the following problems. The proportional control based on the calculation result of the proportional calculation unit 16 has an advantage that the off gauge of the rolled material S is short because the response time from the detection of the plate thickness deviation to the convergence thereof is short, while the proportional control gain If is set excessively, there is a drawback that a control abnormality such as hunting occurs due to disturbance such as material change of the material to be rolled or temperature change. Further, the integral control based on the calculation result of the integral calculation unit 15 has an advantage that a control abnormality due to a disturbance such as a material change of the material to be rolled or a temperature change is unlikely to occur, and the advantage is that the response time described above is long. Since it is based on, there is a drawback that the off gauge becomes long.

Therefore, Japanese Patent Publication No. Sho 61-20368 discloses that
The plate thickness deviation is compared with a preset threshold value, integral control is performed while the plate thickness deviation is below the threshold value, and when the plate thickness deviation exceeds the threshold value, proportional control is performed until the plate thickness deviation converges. A thickness control device is disclosed. In addition, JP-A-63-123504
The publication discloses a thickness control device in which the proportional control gain increases as the plate thickness deviation increases, and the integral control gain decreases accordingly.

[0006]

[Problems to be solved by the invention]
In the conventional thickness control device described in Japanese Patent No. 61-20368, since the proportional control gain in the case of performing proportional control is constant, the occurrence of control abnormality due to disturbance cannot be avoided, and therefore a large proportional control is required. There was a problem that the gain could not be set. Further, in the conventional thickness control device described in JP-A-63-123504, the proportion of the proportional control gain to be increased with respect to the plate thickness deviation is constant, so that when a disturbance occurs, the proportional control gain is proportional. There is a possibility that the control gain becomes excessive and control abnormality occurs. The present invention has been made in view of such circumstances, and an object thereof is to determine a proportional control gain and an integral control gain based on the material of the material to be rolled and the rolling record of the material to be rolled of the same material. It is an object of the present invention to provide a thickness control device capable of obtaining a proportional control gain as large as possible in response to a disturbance by using the configuration.

[0007]

The thickness control device according to the present invention is designed to eliminate the deviation between the target thickness and the thickness of the material to be rolled on the exit side of the rolling mill for rolling the material to be rolled. A thickness control device that adjusts the rolling mill to control the thickness of the material to be rolled based on a proportional calculation value that is proportionally calculated using a control gain and an integral calculation value that is integral calculated using the deviation and the integral control gain. In the first table in which the proportional control gain and the integral control gain are set for each material of the material to be rolled, and a plurality of rolling results of the material to be rolled are classified, and the proportional control gain and the A second table in which a correction value for correcting the integral control gain is set, a storage unit that stores the rolling record of the material to be rolled, and a proportional control corresponding to the first table based on the material of the material to be rolled. A unit for reading the gain and the integral control gain, a unit for selecting a rolling record similar to the rolling record stored in the storage unit from the second table, and a correction value set for the selected rolling record from the second table. Reading means, means for respectively calculating a corrected proportional control gain and a corrected integral control gain from the read proportional control gain and integral control gain, and a correction value; means for performing a proportional calculation using the corrected proportional control gain; Means for performing integral calculation using the corrected integral control gain.

In the first table, a proportional control gain and an integral control gain are set for each material such as material to be rolled, thickness and width. This makes it possible to deal with a change in the material of the material to be rolled. Further, in the second table, a plurality of characteristic patterns are classified among a plurality of deviation patterns obtained by obtaining the deviation between the thickness of the material to be rolled on the outlet side of the rolling mill and the target thickness over the entire length of the material to be rolled. Therefore, a correction value that makes the proportional control gain as large as possible is set for each deviation pattern.

The storage means stores the deviation pattern of the material to be rolled, selects a deviation pattern similar to the deviation pattern stored by the storage means from the deviation patterns classified in the second table, and sets the selected deviation pattern. Read the corrected value. Then, the proportional control gain and integral control gain read from the first table are respectively multiplied by the correction value to obtain a corrected proportional control gain and a corrected integral control gain.

When a plurality of materials to be rolled in the same lot have substantially the same material, thickness and width, the temperature conditions are substantially the same and they are all rolled under substantially the same rolling conditions. Therefore, based on the material of the first material to be rolled in the lot, rolling is performed using the proportional control gain and the integral control gain read from the first table to obtain a deviation pattern, and a deviation pattern similar to this deviation pattern is obtained. The correction value is read from the second table to obtain the correction proportional control gain and the correction integral control gain. By using this correction proportional control gain and the correction integral control gain to roll another rolled material having substantially the same material, thickness and width, it is possible to cope with disturbances such as the material and temperature of the rolled material. A relatively large proportional control gain is obtained, and the thickness deviation can be converged in a short time without causing a control abnormality.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be specifically described below with reference to the drawings. FIG. 1 is a block diagram showing a configuration of a thickness control device according to the present invention, and a schematic side view of a rolling mill, in which S is a material to be rolled such as a steel plate. In the figure, a four-roll type rolling mill 1 equipped with work rolls 11 and backup rolls 12 holding the work rolls 11 and 11 is provided in a transfer area of a material S to be rolled which is rolled in an arrow direction. It is arranged. The work rolls 11, 11 and the backup rolls 12, 12 are driven by the actuator 9, and the work rolls 11, 11 and the backup roll 12, driven by the actuator 9,
The rolling position, rolling load, etc. of 12 are controlled by the drive controller 8.

A thickness gauge 2 for detecting the thickness of the material S to be rolled is arranged on the exit side of the rolling mill 1. The detection result of the thickness gauge 2 is given to the deviation calculator 20. The deviation calculating unit 20 includes the rolled material S
Is also given, the deviation calculation unit 20 subtracts the detected plate thickness from the target plate thickness to obtain a plate thickness deviation, and calculates the plate thickness deviation by the integration calculation unit 5 and the proportional calculation unit 6, and the proportional calculation and integration. Calculation unit of gain determination unit 4 for determining gain used in calculation
Give to each 41.

Each data of the material, plate thickness and plate width of the material S to be rolled is given to the calculating unit 41 of the gain determining unit 4 from the managing computer. Based on the data, the corresponding integral control gain and proportional control gain are read from the gain table 42 in which the integral control gain and proportional control gain are preset for each material, plate thickness and plate width.

FIG. 3 is an explanatory diagram for explaining the contents of the above-mentioned gain table 42. In the gain table 42, a plurality of materials of the material to be rolled are classified, and the plate thickness of the material to be rolled is classified into appropriate ranges for each classification of the material. And
For each section of the plate thickness, the plate width of the material to be rolled is further divided into appropriate ranges, and an integral control gain and a proportional control gain are set for each section of the plate width.
In FIG. 2, the proportional control gain is 1 / the integral control gain.
A small value of about 6 to 1/7 is set.

Further, the arithmetic unit 41 is adapted to be supplied with a signal from the filter 3 which removes noise contained in the output signal of the thickness gauge 2 and outputs the signal. The deviation pattern storage unit 44 stores the pattern of the signal applied over the entire length of the material S to be rolled, that is, the thickness deviation pattern.

FIG. 4 is a waveform diagram showing the output signal of the thickness meter 2 and the output signal of the filter 3 described above. FIG. 4A shows the output signal of the thickness meter 2 and FIG. 4B shows the output signal of the filter 3. Shown respectively. As shown in FIGS. 3A and 3B, high frequency noise is removed by the filter.

Further, in the gain determining unit 4, a gain correction table 43 in which an integral control gain correction value and a proportional control gain correction value are registered for each of a plurality of plate thickness deviation patterns, respectively.
Is provided.

FIG. 5 is an explanatory diagram for explaining the contents of the above-mentioned gain correction table 43. In the gain correction table 43, a plurality of characteristic plate thickness deviation patterns are classified based on a plurality of plate thickness deviation patterns obtained in advance, and a control abnormality occurs corresponding to each plate thickness deviation pattern. Without doing so, the integral control gain correction value and the proportional control gain correction value are set so that the proportional control gain becomes as large as possible.

Then, the calculation section 41 is provided with a gain correction table.
From the plate thickness deviation patterns classified into 43, a plate thickness deviation pattern similar to the plate thickness deviation pattern stored in the deviation pattern storage unit 44 is selected by pattern recognition and set to the selected plate thickness deviation pattern. Read a certain integral control gain correction value and proportional control gain correction value. Computing unit 41
Is the integral control gain and proportional control gain read from the gain table 42 and the integral control gain correction value and proportional control gain correction value read from the gain correction table 43 to obtain the corrected integral control gain and the corrected proportional control gain. Then, the corrected integral control gain is given to the integral calculation section 5, and the proportional control gain correction value is given to the proportional calculation section 6.

FIG. 2 is a flow chart showing a calculation procedure of the calculation unit 41 described above. The calculation unit 41 reads out the proportional control gain and the integral control gain from the gain table 42 based on the material of the material S to be rolled (step S).
1).

Further, the calculation unit 41 stores the plate thickness deviation pattern of the rolled material S from which the noise is removed by the filter 3 in the deviation pattern storage unit 44 (step S2), and the plate stored in the deviation pattern storage unit 44. The thickness deviation pattern and each of the plate thickness control patterns classified in the gain correction table 43 are respectively recognized, and a plate thickness deviation pattern similar to the plate thickness deviation pattern stored in the deviation pattern storage unit 44 is acquired by the gain correction table 43. Is selected (step S3). The calculation unit 41 reads the integral control gain correction value and the proportional control gain correction value set in the strip thickness deviation pattern selected in the gain correction table 43 (step S4), and reads the integral control gain and the proportional control read from the gain table 42. The gain is multiplied by the integral control gain correction value and the proportional control gain correction value read from the gain correction table 43 to obtain the corrected integral control gain and the corrected proportional control gain (step S5).

Then, as shown in FIG. 1, another material S to be rolled having substantially the same material, thickness and width in the lot.
In rolling, the integral calculation unit 5 includes a corrected integral control gain given by the calculation unit 41 of the gain determination unit 4, a plate thickness deviation of the material S to be rolled given by the deviation calculation unit 20, and the following (1 ), The integral calculation is performed based on the equation, and the result is given to the addition unit 7. Further, the proportional calculation unit 6 is proportional based on the corrected proportional integral control gain given from the calculation unit 41, the plate thickness deviation of the rolled material S given from the deviation calculation unit 20, and the following equation (2). The calculation is performed and the result is given to the addition unit 7. The adder unit 7 adds up the integral calculation value and the proportional calculation value and gives them to the drive control device 8 so that the actuator 9
The rolling position of the rolling mill 1 is adjusted by
Remove the plate thickness deviation. _{ΔS MI = K I · (M} + Q) / M · 1 / Σt · 1 / SΔhx ... (1) where, [Delta] S _MI: integral control output K _I: corrected integral control gain M: mill modulus Q: Plastic coefficient t: thickness meter Running time until Δhx: Thickness deviation ΔS _MP = −K _P (1 / Σt) · Δhx (2) where ΔS _MP : Proportional control output K _P : Corrected proportional control gain

[0023]

EXAMPLES The results of the comparative tests will be described below. FIG. 8 is a graph showing rolling results by the conventional thickness control device, and FIG. 6 is a graph showing rolling results by the thickness control device according to the present invention. In both figures, (a) shows the output of the integral control computing unit, (b) shows the output of the proportional control computing unit,
Further, (c) shows the plate thickness deviation.

As is apparent from FIGS. 6 and 8, in the thickness control device according to the present invention, the output of the integral control calculation part is substantially the same as that of the conventional thickness control device, but the proportional control calculation is performed. The output of the section is as large as possible, and as a result, the plate thickness deviation at the initial stage of rolling due to the roll gap error is quickly eliminated, and thereafter the plate thickness deviation hardly occurs.

[0025]

As described above in detail, in the thickness control device according to the present invention, the proportional control gain can be increased as much as possible without causing a control abnormality in accordance with a disturbance. Therefore, the plate thickness deviation at the initial stage of rolling due to the roll gap error can be quickly eliminated, and the off gauge can be reduced. Further, since the thickness control operation is fast in the middle of the rolling, the thickness of the material to be rolled is controlled with high accuracy, and the present invention has excellent effects.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a thickness control device according to the present invention and a schematic side view of a rolling mill.

FIG. 2 is a flowchart showing a calculation procedure of a calculation unit.

FIG. 3 is an explanatory diagram illustrating contents of a gain table.

FIG. 4 is a waveform diagram showing an output signal of a thickness gauge and an output signal of a filter.

FIG. 5 is an explanatory diagram illustrating contents of a gain correction table.

FIG. 6 is a graph showing rolling results by the thickness control device according to the present invention.

FIG. 7 is a block diagram showing a conventional thickness control device.

FIG. 8 is a graph showing a rolling result by a conventional thickness control device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Rolling mill 2 Thickness gauge 3 Filter 4 Gain determination unit 5 Integral calculation unit 6 Proportional calculation unit 7 Addition unit 42 Gain table 43 Gain correction table

Claims (1)

[Claims] 1. A proportional operation value calculated proportionally using the deviation and a proportional control gain in order to eliminate a deviation between the thickness of the material to be rolled and a target thickness on the exit side of a rolling mill for rolling the material to be rolled, and A thickness control device that controls the thickness of a material to be rolled by adjusting the rolling mill based on an integral calculation value obtained by performing an integral calculation using the deviation and the integral control gain, wherein the proportional control gain for each material of the material to be rolled and A first table in which integral control gains are respectively set and a plurality of rolling records of rolled materials are classified, and correction values for correcting the proportional control gain and the integral control gain are set in each classification. A second table, a storage means for storing the rolling record of the material to be rolled, and a means for reading the corresponding proportional control gain and integral control gain from the first table based on the material of the material to be rolled. A means for selecting a rolling result similar to the rolling result stored in the storage means from the second table, a means for reading a correction value set for the selected rolling result from the second table, a read proportional control gain, and Means for respectively calculating a correction proportional control gain and a correction integral control gain from the integral control gain and the correction value, means for performing a proportional calculation using the correction proportional control gain, and an integral calculation using the corrected integral control gain. And a means for performing the thickness control.