JPH11290919A - Device for controlling eccentricity of roll - Google Patents

Abstract

PROBLEM TO BE SOLVED: To correct the gain and phase of each frequency and to enable a high-accuracy control of roll eccentricity by on-line outputting the variation of thickness deviation caused by the roll eccentricity as the control output wave which is generated using frequency analysis and executing the frequency analysis of the feedback signal for its control. SOLUTION: About the frequency decided by analyzed frequency deciding process 13, the amplitude and phase of a waveform are measured by executing the process 14 of waveform analysis and the waveform of each frequency is reproduced from that result. The reproduced waveform is corrected for every frequency on the basis of the gain and delayed phase of the whole control system which is judged by output gain phase analyzing process 16 and, by combining them, outputted as the control signal of roll eccentricity and the variation of thickness deviation due to the roll eccentricity is corrected.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the control of roll eccentricity, and more particularly to the control of the thickness of a rolling mill for rolling a material by a rolling roll such as a hot or cold rolling mill. The present invention relates to a roll eccentricity control device suitable for improving a thickness variation caused by eccentricity of a roll.

[0002]

2. Description of the Related Art Conventionally (Japanese Patent Publication No. 56-49644), a waveform of a thickness deviation due to eccentricity of a roll (hereinafter referred to as a deviation waveform).
The deviation waveform is reproduced using the Fourier transform principle. As shown in FIG. 4, the reproduced waveform is subjected to constant enlargement / reduction (gain correction) and time shift (phase correction) to output the thickness control. Therefore, in the case of the conventional control, an output capable of canceling the thickness deviation at the rotation frequency of the roll was possible.
However, since the waveform of the control output is actually deformed before the operation, the roll eccentric component cannot be removed with high accuracy. This is because a control system such as a hydraulic pressure reduction device that adjusts the position of a rolling roll has a response characteristic such as a low-pass filter in which the gain and the lag phase increase as the frequency of the input signal increases, and the deviation waveform includes various frequency components. Due to being out. In addition, since the response characteristic itself of the control system changes depending on the state such as the temperature, the deformation of the output waveform cannot be corrected.

[0003]

The conventional concept has the following problems. Control errors due to the gain and phase of the control system cannot be suppressed (control optimization).
In a high-frequency component having a large phase delay, there is even a possibility that the thickness variation may be amplified depending on conditions.

[0004] An object of the present invention is to provide various frequency components due to roll eccentricity online without being affected by changes in the response characteristics of a mechanical system such as a hydraulic pressure reduction device, regardless of the rotation state of the roll. An object of the present invention is to provide a roll eccentricity control device capable of suppressing and controlling a thickness variation with high accuracy.

[0005]

The solution is achieved by the following means.

1) Frequency analysis of a deviation waveform due to roll eccentricity is performed, and a waveform reproduced with an amplitude and a phase measured for each frequency is synthesized and output.

2) The frequency of the feedback of the control result is analyzed again, and the gain and phase of the control system, which are control errors, are measured, corrected for each frequency, and output.

That is, the following effects can be obtained by the above means.

1) An accurate mechanical system such as a hydraulic pressure reduction device,
Response characteristics can be measured.

[0010] 2) The thickness fluctuation including various frequency components due to the roll eccentricity can be suppressed with high accuracy on-line.

[0011]

Embodiments of the present invention will be described below.

First, the basic contents according to the features of the present invention are as follows:
The thickness variation due to the roll eccentricity basically has a periodicity for each rotation of the roll, but the waveform of the actual thickness variation includes the change in the relative angle between the upper and lower rolls and the deviation of the backup roll. It is a waveform as shown in FIG. 2 including various frequency components caused by a change in the relative angle between the core and the upper and lower backup rolls. A control system such as a hydraulic pressure reduction device used for control has a response characteristic such as a low-pass filter. Focusing on the fact that the gain and phase are different for each frequency and that the response characteristics themselves change due to factors such as temperature, determine the generated gain and delay phase using the feedback result of the control result for each frequency, and synthesize the waveform. Performs correction to cancel the gain and phase determined previously for each frequency, synthesizes control waveforms on the assumption that they will be deformed by the control system, and controls the roll position according to the waveforms. Is Umono.

As an example of a rolling mill to which the present invention can be applied,
FIG. 1 shows a schematic configuration of the main part. The rolling mill shown in FIG. 1 is of a reversible type, and a rolling roll 1 includes an upper and lower work roll 1a (radius: ra) and an upper and lower backup roll 1b.
(Radius: rb), the rolled material 2 is inserted between the upper and lower work rolls 1 a, and both ends thereof are wound around a left reel 5 and a right reel 6 via deflores 3 and 4, respectively. The lower work roll is provided with a roll rotation angle detector 11. Thickness gauges 7a and 7b for detecting the thickness of the rolled material 2 are provided on the entrance and exit sides of the roll 1 at a position h away from the center line of the roll and close to the roll 2. A load cell 8 for measuring a rolling load is provided in the rolling roll 1.
Is provided.

In the roll eccentricity control device, based on the signal from the roll rotation angle detector 11, the start of each arithmetic processing and the timing for generating the timing for taking in the signals of the thickness gauges 7a, 7b and the load cell 8 are generated. Generator 12, an analysis frequency determining process 13 for determining a frequency for performing roll eccentricity control based on measured thickness data and rolling load 13,
A waveform analysis 14 for analyzing the amplitude and phase of each frequency component determined in the analysis frequency determination processing 13, a sine wave generation 15 for generating a sine wave and a cosine wave of each frequency determined in the analysis frequency determination processing 13, Output gain phase analysis 16, waveform analysis 14, and phase analysis 1 for comparing with the previous output waveform and analyzing the gain and phase of the control system
Sine wave generation 15 based on the amplitude and phase analyzed in 6
An output gain phase correction 17 for correcting the sine wave and cosine wave generated by the above and reproducing each frequency waveform, and a roll eccentric waveform synthesizing 18 for synthesizing each frequency waveform reproduced by the output gain phase correction 17 are provided. .

Using a signal output from the roll eccentricity control device, a roll gap, which is an interval between the upper and lower work rolls 1a, is adjusted by a hydraulic pressure reduction device 10 controlled by a hydraulic pressure reduction control device 9, and the rolled material 2 Is controlled.

Here, the plate is flowing from left to right in FIG. 1 for rolling, and thickness gauges 7a and 7b are used as means for detecting a thickness variation due to roll eccentricity. In the FFT calculation and waveform analysis 14 as a method of (4), the case where Fourier transform is used will be described along the flow of FIG. 1 and FIG. 13 showing a change in a temporal processing state.

First, based on the signal measured by the roll rotation detectors 11, the timing at which the rotation of the roll for removing the eccentric component becomes equal to n (1 ≦ n) is determined by the timing generator 12. Then, the signal of the thickness gauge 7b is fetched and the number of data necessary for the FFT operation of the analysis frequency determination processing 13 is sampled. Then, the analysis frequency determination processing 13 determines p (p ≧ 1) frequencies that are characteristic of the thickness variation due to the roll eccentricity.

A sine wave and a cosine wave serving as a reference for the frequency determined in the analysis frequency determination processing 13 are generated by a sine wave generator 15.

The signal of the thickness gauge 7 b fetched at the above-mentioned timing generated from the timing generator 12 and the reference sine and cosine waves generated in the analysis frequency determination processing 13 are p Are integrated for n1 periods (1 ≦ n1) for each frequency of, and the reference sine wave amplitude is measured from the integrated value with the reference sine wave, and the reference cosine wave amplitude is measured from the integrated value with the reference cosine wave. Q1 in FIG. 13 is the measured p reference sine wave amplitudes and reference cosine wave amplitudes.

Next, R1 is controlled using Q1 in FIG. In the output gain phase correction 17, the measured reference sine wave amplitude and reference cosine wave amplitude are respectively set to the amplitudes of the sine wave and cosine wave generated by the sine wave generator 15, and p sine waves are generated by the roll eccentric waveform synthesis 18. Combine and output all waves and cosine waves to perform roll eccentricity control.

However, at this time, since the gain and phase of the control system are not taken into consideration, the thickness of R1 'fluctuates as a control error.

After the plate as a result of the R1 control has traveled the distance h and waited until it was detected by the thickness gauge 7b, the reference sine wave amplitude and reference cosine wave amplitude are again determined by the waveform analysis 14. Measure. This is the measured state Q2 of R1 'shown in FIG.

Normally, the gain and phase of the control system change less frequently than the thickness variation waveform due to the change in the roll state. Therefore, Q2 is the result of the variation in the thickness variation waveform and is added to R1 described above. Performs roll eccentricity control. FIG.
(R1 + R2).

Therefore, the gain and phase (Q
In order to make the correction of 2) the control output, Q3, which is the third analysis result, is detected as a value twice as large as Q2. In the output gain phase analysis 16, the detected output gain phase analysis result Q is compared with the previous value, and if there is an amplification tendency, the determined Q is regarded as a gain and a phase by the control system. In the phase correction 17, a correction for compensating the determined gain and phase Q2 of the control system is performed (S2 in FIG. 13), and the roll eccentricity control is output, so that the optimized and highly accurate roll eccentricity control is performed. It becomes possible. Hereinafter, this control will be described using mathematical expressions.

Here, in conjunction with the above-described premise, a case where an FFT operation of 2 i (i ≧ 1) is used as an example will be described along the flow of FIG. 11 and FIG.

The thickness data measured at the above timing is sequentially stored, and 2 i (i ≧ 1) data are sampled to determine the analysis frequency.

An FFT operation is performed on the sampled data to determine an analysis frequency.

The sine wave amplitudes S0 to S0, which are the result of the FFT operation,
Sj (j = 2 ^i-1 -1) and cosine wave amplitudes C0 to Cj (j =
2 ⁱ⁻¹ −1), the amplitude (Sm ² + Cm ² ) ^1/2 (0 ≦
(m ≦ j) is determined as p (p ≧ 1), the frequency for performing the roll eccentricity control as ωt, 3ωt, and 5ωt in FIG. 2 is determined. A wave and a reference cosine wave are generated, and roll eccentricity control processing of the frequency components determined thereafter is performed.

By the above timing, a software interrupt (FIG. 1)
2) is performed, and the processing of the waveform analysis 14 is performed in the interrupt processing.

The sheet thickness data and the rolling load measured at the above timing (sampled by the interruption processing) and the rolling load are integrated for k cycles (k: natural number), and Σsheet thickness data × sine wave:
a, Σ thickness data x cosine wave: b, Σ rolling load x sine wave:
c, Σrolling load × cosine wave: d are calculated.

The amplitude is calculated from the obtained a and b, the phase is calculated from c and d, and the reference sine wave amplitude A and the reference cosine wave amplitude B are calculated.

[0032]

(Equation 1)

[0033]

(Equation 2)

This calculation is individually determined for the obtained p frequencies, the sine wave generator 15 generates a roll eccentric waveform f by the above calculation, and the roll eccentricity control is performed by the output signal f1. As an example, when focusing on 3ωt in FIG. 5, the equation of the detected waveform is as follows.

[0035]

[Equation 3] Roll eccentric waveform: f = − ／ cos3ωt (general formula: f = Asinωt + Bcosωt) (Equation 3)

[0036]

[Formula 4] Roll eccentricity control output: f1 = 1/3 cos3ωt (general formula: f1 = −Asinωt−Bcosωt) (Equation 4) ωt: Frequency Mechanical system until the roll eccentricity control output acts on an actual plate And a phase (20% attenuation and 10 degree phase in the case of 3ωt in the example) are generated, so that the control output f during operation is f
1 'becomes like Equation 5,

[0037]

(Equation 5)

The actual waveform which is the synthesis of each frequency is shown in FIG.
It becomes like. Therefore, the waveform f2 of the sheet thickness, which is the actual operation result, is obtained after the elapse of the h / 2rbπ rotation time when the rolled material 2 moves from the rolling roll 1 to the thickness gauge 7a or 7b (distance h).

[0039]

(Equation 6)

FIG. 9 shows a measurement waveform which is a combination of the respective frequencies.

Therefore, in the output gain phase analysis 16, the amplitudes of the next reference sine and cosine waves, which are the results of the waveform analysis processing, are obtained.
(A-β (Acosα-Bsinα)) and (B-β (Asinα + Bc
osα)), and these are defined as A ′ and B ′.
The operation of Expression 8 is performed.

[0042]

Equation 7] A (A-A ') + B (B-B') / (A 2 + B 2) = A (A- (A-β (Acosα-Bsinα))) + B (B- (B-β ( Asinα + Bcosα))) / ( A 2 + B 2) = A (β (Acosα-Bsinα)) + B (β (Asinα + Bcosα))) / (A 2 + B 2) = β (A 2 cosα-ABsinα + ABsinα + B 2 cosα) / ( A ² + B ² ) = β (A ² + B ² ) cosα / (A ² + B ² ) = βcosα (Equation 7)

[0043]

Equation 8] B (A'-A) + A (B-B ') / (A 2 + B 2) = B ((A-β (Acosα-Bsinα)) - A) + A (B- (B-β ( Asinα + Bcosα))) / ( A 2 + B 2) = B (-β (Acosα-Bsinα)) + A (β (Asinα + Bcosα))) / (A 2 + B 2) = β (-ABcosα + B 2 sinα + A 2 sinα + ABcosα) / ( A ² + B ² ) = β (A ² + B ² ) sin α / (A ² + B ² ) = βsin α (Equation 8) In the case of 3ωt, the following equation is obtained.

[0044]

A (AA ′) + B (BB ′) / (A ² + B ² ) = − ／ (− 1/3 − (− 1/3 + 4 / 15cosπ / 18)) / (− 1/3) ² = (− 4/15 cosπ / 18) / (− ３) = 4/5 cosπ / 18 B (A′−A) + A (B−B ′) / (A ² + B ² ) = − ／ (4 / 15 sinπ / 18) / (-／) ² = (4/15 sinπ / 18) / (-／) =-4/5 sinπ / 18 From the above, ((βsinα) ² + (βcosα) ² ) ^1/2 = β = 4/5: (3ωt term Case)… (Equation 9)

[0045]

(Βsinα) / β = sinα = −sinπ / 18: (in the case of 3ωt term) (Equation 10)

[0046]

(Β cos α) / β = cos α = cos π / 18: (in the case of 3ωt term) (Equation 11) The above calculation is performed, and the roll eccentricity control output is generated until it acts on the actual plate. Gain and phase (20% attenuation and 10 degree phase in the case of the 3ωt term in the example) due to the mechanical system.

Normally, the waveform analysis processing results A 'and B' are added to the previous control amounts A and B as changes in the roll eccentric waveform, respectively.
The value approximating α and cosα is the number of consecutive judgments w (w ≧ 2)
If the above is continuously calculated, the output gain phase correction 17
The following equation is corrected.

[0048]

A ″ = − (A cos α + B sin α) / β = −5 / 12 sin π / 18: (in the case of 3ωt) (Equation 12)

[0049]

B ″ = − (Bcosα−Asinα) / β = 5/12 cosπ / 18: (in the case of 3ωt) (Formula 13) A waveform using A ″ and B ″ is generated.

[0050]

[Equation 14]

Until the roll eccentricity control output acts on the actual plate, the gain and phase by the mechanical system (in the case of 3ωt in the example, 2
0% attenuation and a phase of 10 degrees), the control output f3 'during operation becomes as shown in Expression 14.

[0052]

## EQU15 ## Control output during operation: f3 '=-4/5 (5/12 sin.pi./18) sin (3.omega.t -.pi./18)+4/5 (5/12 cos .pi. / 18) cos (3.omega.t -.pi./18)= -1/3 ((sinπ / 18sin3ωtcosπ / 18 -cos3ωtsin 2 π / 18) - (cos 2 π / 18cos3ωt + cosπ / 18sin3ωtsinπ / 18)) = 1 / 3cos3ωt = -f general formula: f3 '= β (- ( ( Acosα + Bsinα) / β) sin (ωt + α) - ((Bcosα-Asinα) / β) cos (ωt + α)) = - (Acosα + Bsinα) (sinωtcosα + cosωtsinα) - (Bcosα-Asinα) (cosωtcosα-sinωtsinα) = -Asinωtcos 2 α-Bsinαsinωtcosα ^{-Asinαcosωtcosα-Bcosωtsin 2 α -Bcosωtcos 2 α} + Asinαcosωtcosα + Bsinαsinωtcosα-Asinωtsin 2 α = -Asinωt-Bcosωt = -f ... ( number 15) deviation which is a result of the action is zero. FIG. 13 shows a temporal change of the above operation.

The same correction is performed for p frequency components determined as analysis frequencies.

FIG. 10 shows a waveform obtained by synthesizing all the corrected waveforms. By outputting the combined waveform as a roll eccentricity control signal, it is possible to compensate for the gain and phase generated when the roll eccentricity control output is applied to the rolled material, and high-accuracy roll eccentricity control is realized.

[0055]

During roll eccentricity control, different gains and phases are generated in the roll eccentricity control signal for each frequency due to the response characteristics of the hydraulic pressure reduction device and the hydraulic pressure reduction control device for controlling the position of the rolling roll. The signal waveform is deformed. As a result, an error occurs in the roll eccentricity control, and a deviation occurs in the thickness of the rolled material. The frequency of the hydraulic pressure reduction device and the hydraulic pressure reduction control device are analyzed by comparing the frequency of the feedback signal and comparing and calculating the detected waveform (waveform before control), the control output waveform, and the feedback waveform (waveform after control) for each frequency. Different gains and phases can be detected for each case. Then, by correcting the gain and phase detected for each frequency and synthesizing the corrected waveforms of the respective frequencies, it is possible to perform a roll eccentricity control output that provides an optimal waveform at the time of operation in anticipation of the deformation of the signal waveform. . As a result, it is possible to suppress the thickness variation including various frequency components caused by the eccentricity of the roll online with high accuracy.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a rolling roll for explaining a basic configuration of the present invention.

FIG. 2 is a schematic waveform diagram for explaining a basic process of the present invention.

FIG. 3 is a schematic waveform diagram for explaining an output gain phase analysis process of the present invention.

FIG. 4 is a schematic waveform diagram for explaining a conventional roll eccentricity control process.

FIG. 5 is a diagram of an example of a roll eccentric waveform for each frequency.

FIG. 6 is a waveform chart showing an example of a roll eccentric waveform obtained by combining the waveforms of FIG. 5;

FIG. 7 is a diagram of an output waveform of a conventional roll eccentricity control.

FIG. 8 is a diagram of a waveform when the control output of FIG. 7 operates.

FIG. 9 is a diagram of a waveform of a thickness deviation, which is an operation result (waveform of FIG. 6 + waveform of FIG. 8).

FIG. 10 is a diagram of an output waveform of roll eccentricity control according to the present invention.

FIG. 11 is a schematic diagram for explaining software main task processing according to the present invention.

FIG. 12 is a schematic diagram for explaining software interrupt task processing according to the present invention.

FIG. 13 is a schematic diagram for explaining a temporal change in roll eccentricity control according to the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Rolling roll, 1a ... Work roll, 1b ... Backup roll, 2 ... Rolled material, 3 ... Left deflor, 4 ... Right deflor, 5 ... Left reel, 6 ... Right reel, 7a ... Left thickness gauge, 7b ... Right thickness Total, 8 ... Load cell (load meter), 9 ...
Hydraulic pressure reduction control device, 10: hydraulic pressure reduction device (hydraulic jack, etc.), 11: roll rotation angle detector (PLG, etc.), 12 ...
Timing generator 13, 13 analysis frequency determination processing, 14
... waveform analysis, 15: sine wave generation, 16: output gain phase analysis, 17: output gain phase correction, 18: roll eccentric waveform synthesis, h: distance between rolling rolls of thickness gauge, ra: work roll radius, rb: backup Roll radius.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Masaaki Nakajima 5-2-1, Omika-cho, Hitachi City, Ibaraki Prefecture Inside the Omika Plant of Hitachi, Ltd. No. 2-1 Hitachi Process Computer Engineering Co., Ltd. (72) Inventor Naohiro Sakaki 5-2-1 Omika-cho, Hitachi City, Ibaraki Prefecture Hitachi Process Computer Engineering Co., Ltd.

Claims (9)

[Claims] 1. A rolling machine equipped with a rolling device for controlling the position of a roll based on a rolling position signal and applying a rolling load to a rolled material through the roll, wherein the eccentricity of the roll is determined. In a roll eccentricity control device for detecting and controlling the rolling position signal to remove the eccentricity amount, a deviation detecting means for detecting a deviation of the thickness of the rolled rolled material, and a deviation of the deviation detected by the deviation detecting means. The characteristic frequency of the waveform is n
Number (n ≧ 1) of characteristic frequency analysis means, waveform analysis means for determining the amplitude and phase of each of the n frequencies determined by the characteristic frequency analysis means, and the amplitude determined by the waveform analysis means Sine wave output means for reproducing n waveforms in accordance with the phase, roll eccentricity control signal output means for synthesizing the n waveforms reproduced by the sine wave output means, and outputting as the roll-down position signal; A gain and a lag phase generated before the rolling position signal output by the lead control signal output means acts on the rolled material are determined by the waveform analysis means for each of the n frequencies determined by the characteristic frequency analysis means. Output gain phase analyzing means for determining from the obtained amplitude and phase, and correction for canceling the gain and lag phase determined by the output gain / phase analyzing means. Output gain phase correction means applied to the n waveforms reproduced by the sine wave output means, the deviation detection means, the waveform analysis means, the sine wave output means, the roll eccentricity control signal output means, and the output gain phase A roll eccentricity control device comprising: an analysis unit; and a timing device that outputs an operation timing to the output gain phase correction unit. 2. A roll eccentricity control device according to claim 1, wherein said deviation detecting means directly measures the thickness of the rolled material on the exit side of the rolling machine. 3. The roll eccentricity control device according to claim 1, wherein said deviation detecting means calculates a thickness based on a detected load output from a rolling load detector. 4. The apparatus according to claim 1, wherein the deviation detecting means directly measures the thickness of the rolled material on the exit side of the rolling machine and calculates the thickness based on the detected load output from the rolling load detector. The characteristic frequency analysis means, the waveform analysis means, and the output gain phase analysis means use data for directly measuring the plate thickness for the determination of the amplitude and the gain, and calculate the thickness based on the load for the determination of the phase. A roll eccentricity control device characterized by using data to be processed. 5. The roll eccentricity control device according to claim 1, wherein said characteristic frequency analysis means determines a frequency with respect to an integral multiple of a roll rotation frequency for performing eccentricity control. 6. The characteristic frequency analysis means according to claim 1, wherein the characteristic frequency analysis means performs an FFT operation and performs the FFT operation at least once based on an amplitude of a frequency determined and controlled by the waveform analysis means. A roll eccentricity control device for making a determination. 7. The method according to claim 6, wherein F is calculated a plurality of times.
A roll eccentricity control device for correcting the phase of each FT calculation result, averaging the results, and calculating the amplitude. 8. The apparatus according to claim 1, wherein the timing device is configured to control the rotation of the roll for performing the eccentricity control at a constant angle, which is obtained from the rotation speed ratio of the roll for performing the eccentricity control and the roll having the rotation angle detector. A roll eccentricity control device for generating timing. 9. The roll eccentricity control device according to claim 1, wherein the timing device generates a timing after a predetermined time has elapsed.