JPH05200423A - Thickness deviation disturbance control method - Google Patents

Abstract

(57) [Abstract] [Purpose] Simultaneous reduction of the two major disturbances in plate thickness control, the skid mark disturbance and the roll eccentricity disturbance in the finish rolling process of the hot rolling process, realizes highly accurate total thickness thickness accuracy. .. [Constitution] ΔF = − [by the tuning factor α, the plasticity coefficient Q [kgw / mm] of the rolled material, the integral constant G [1 / sec], and the Laplace operator s [1 / sec]). Δs + (α / M) ・ ΔP] ・ [(M + Q) / M] ・ G /
ΔF [mm] is calculated by the dynamic characteristic calculation of s, and the reduction system mechanism operation command amount Δu [mm] is calculated by ΔF [mm] and the reduction reference (ΔR _r [mm]) as Δu = ΔR _r −ΔF The skid mark disturbance near 0.2 to 1.0 [Hz] and the roll eccentric disturbance near 4.0 to 10.0 [Hz] are simultaneously reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic strip thickness control system for rolling mills.

[0002]

2. Description of the Related Art In recent years, in thickness control, for example, "Plasticity and Machining" Vol.16 no.168 (1975-1) P.25-P.31 and "Journal of System Control Information Society" Vol.2, No. .5, P.147 ~ P.154,1989
And “Theory and practice of strip rolling” P.223 to P.256, etc., as shown in the automatic strip thickness deviation control system (hereinafter, AGC (Automatic
Called Gauge Control).

The inventors of the present invention have proposed a method for simultaneously reducing skid marks and roll eccentricity in Japanese Patent Application No. 278519.
I am proposing an issue.

The prior art will be described below with reference to the drawings.

FIG. 7 is a diagram showing a conventional rolling system incorporating an automatic plate thickness deviation control system. In FIG. 7, 1 is a rolling mill, 2 is a rolled material, 3 is a rolling position detector, and 4 is a rolling position detector.
Is a rolling load meter, 5 is a reduction mechanism, 6 is an automatic plate thickness deviation control system, and when the rolling mill 1 is rolling the rolled material 2,
The automatic plate thickness deviation control system 6 receives a signal from the rolling load meter 4 and a signal from the reduction position detector 3 as inputs and outputs a reduction position control signal to the reduction mechanism 5.

The structure of a conventional automatic plate thickness deviation control system 6 is shown by I in FIG. FIG. 8 is a conventional plate thickness deviation control system I
Is a block diagram showing the principle diagram of a rolling system equipped with. In FIG. 8, M: rolling mill rigidity coefficient [kgW / mm] Q: rolling material plasticity coefficient [kgW / mm] Δu: rolling system mechanism operation command amount [mm] ΔS: rolling position deviation [mm] ΔP: rolling load deviation [kgW] G _R: transfer function of the pressure mechanism [---] Δh: exit side thickness deviation [mm] [Delta] H: thickness at entrance side deviation [mm] ΔS _e: b - Le eccentricity [mm] ΔR _r: reduction Reference [Mm] I: Automatic plate thickness deviation control system (indicated by a chain line) C ₁ : 1 when a signal representing the rolling position deviation (ΔS) is used, 1 when not using the signal representing the rolling position deviation (ΔS) 0 [---] C ₂ : Convert rolling load deviation signal into strip thickness deviation signal [mm
/ kgW] C ₃ : A general transfer function [---], which is equipped with a conventional automatic plate thickness deviation control system by giving a specific transfer function to C ₁ , C ₂ and C ₃ . It becomes a rolling system. The deviation referred to here means a deviation from a reference value.

In FIG. 8, a transfer function G ₁ from the inlet side thickness deviation (ΔH) to the outlet side thickness deviation (Δh) and a transfer function from the roll eccentricity (ΔS _e ) to the outlet side thickness deviation (Δh). G ₂
It is, W = Q / (M + Q) using _{··· (3), G 1 =} W · (1-M · G R · C 3 · C 2 + G R · C 3 · C 1) / (1- _{M · W · G R · C} 3 · C 2 + G R · C 3 · C 1) ··· (4) G 2 = (1-W) · (1 + G R · C 3 · C 1) / (1- _{M · W · G R · C} 3 · C 2 + G R · C 3 · C 1) is expressed as (5), for any _{C 1, C 2, C 3} , G 1 + G 2 = 1 ... (6) is established.

Therefore, the conventional AGC has a property that if one of the characteristics G ₁ and G ₂ is determined, the other is automatically determined.

Hereinafter, a conventional method for controlling the plate thickness of a steel plate will be described in detail with reference to FIGS. 8, 9 and 10.

First, Mill Modulus Control type A
A rolling system equipped with GC will be described.

Mill Modulus Control type AGC
Means that a representative value of C ₁ = 0 (7) C ₂ = α / M (8) C ₃ = 1 (9) in FIG. 8 is adopted. .. Specifically, it is shown in FIG.

However, in FIG. 9, α is a tuning factor [---] (α: an arbitrary real number), and G _R is T ₁ when a high-speed reduction mechanism such as a hydraulic reduction mechanism is used. : Time constant [sec] However, using T ₁ << ₁ , G _R = 1 / (1 + T ₁ s) (10)

At this time, the transfer function G ₁ from the entrance side thickness deviation (ΔH) to the exit side thickness deviation (Δh) and the roll eccentricity (ΔS _e)
) To the exit side plate thickness deviation (Δh), the transfer function G ₂ is: G ₁ = W · [T ₁ s + (1-α)] / T ₁ s + (1-W · α) (11) ) is a _{G 2 = (1-W)} · (T 1 · s + 1) / _{[T 1 · s + (1-} W · α) ] (12).

Next, a rolling system equipped with a Gauge Meter type AGC will be described. That is, in FIG. 8, it is defined as a case where a representative value of C ₁ = 1 ... (13) C ₂ = α / M (14) C ₃ = G / s (15) is adopted. .. Specifically, it is shown in FIG. A rolling system equipped with a Gauge Meter type AGC generally has an automatic plate thickness deviation control system I, but a Mill Modulus Control type A
The difference from GC is that in the automatic plate thickness deviation control system I, C ₂ is the same functional system, but C ₁ is different.

Further, in the Gauge Meter type AGC,
Using the signal (ΔS) representing the rolling position deviation and the signal (ΔP) representing the rolling load deviation, Δh = Δs + (α / M) · ΔP (16) Based on the Gauge Meter formula (Δ
h) and make feedback.

In FIG. 10, α: tuning factor [---] (0 ≦ α ≦ 1) s: Laplace operator [1 / sec] The Laplace operator is written as 1 / s. If

[0017]

[Equation 1]

Means to carry out. Further, G is an integration constant [1 / sec].

G _R can be expressed as G _R = 1 / (1 + T ₁ s) (17) when a high-speed reduction mechanism such as a hydraulic reduction mechanism is used.

However, T ₁ : time constant [sec] and T ₁ << ₁ .

At this time, the transfer function G ₁ from the inlet side thickness deviation (ΔH) to the outlet side thickness deviation (Δh) and the roll eccentricity (ΔS).
The transfer function G ₂ from _e ) to the outlet plate thickness deviation (Δh) is: G ₁ = W [T ₁ · s ² + s + G (1-α)] / [T ₁ · s ² + s + G (1-α · W) ] it is a _{··· (18) G 2 = (} 1-W) (T 1 s 2 + s + G) / ^{_{[T 1 · s 2 + s +}} G (1-α · W) ] ... (19).

[0022]

However, the conventional control method using the automatic internal plate thickness deviation control system has the following problems.

In the hot rolling process, changes in plasticity coefficient (ΔQ [kgW / mm]), rolling mill entrance side plate thickness deviation (ΔH [mm]), and roll eccentricity (ΔS _e [mm]) , Greatly affect the strip thickness deviation (Δh [mm]) of the rolling mill.

ΔQ is the distance between the skids, which is the deformation resistance in the longitudinal direction of the slab that occurs mainly because the skid supporting the slab in the heating furnace causes temperature unevenness having a period equal to the distance between the skids in the longitudinal direction of the slab. The deviations have the same period, which causes a large deviation in the strip thickness on the delivery side of the rolling mill. This is commonly referred to as skid mark.

ΔH is a strip thickness deviation on the inlet side of the rolling mill. In the rolling mill installed in the tandem, the strip thickness deviation caused by the skid mark (ΔQ) in the former rolling mill is caused by rolling in the next rolling mill. Is included in the inlet side plate thickness deviation. Below, the skid mark is calculated as the deviation of the inlet plate thickness (ΔH).
(Q) is included.

ΔS _e is the backup roll of the rolling mill.
Fluctuation of the rolling load caused by the eccentricity of the roll due to the key groove of the bearing portion of the roll is the plate thickness deviation caused by the deviation of the rolling position. It is called.

The skid mark is a disturbance of 0.2 Hz to 1.0 Hz, the roll eccentricity is a disturbance of 4.0 [Hz] to 10.0 [Hz], and the frequency bands are close to each other.

If the conventional automatic plate thickness deviation control system I is not used or if the usage method is inappropriate even if it is used, the horizontal axis is the time [sec] and the vertical axis is the plate thickness [mm]. As shown in the product plate thickness graph of FIG. 14, a large plate thickness deviation of about 100 [μm] occurs.

In FIG. 14, a wave having a large period is caused by the deviation of the plate thickness on the entrance side such as a skid mark, and a wave having a small period is caused by the roll eccentricity.

Even when the conventional automatic plate thickness deviation control system I is used, the horizontal axis represents time [sec] and the vertical axis represents plate thickness [m
m], as shown in the product thickness graph of FIG.
Thickness deviation is not reduced.

In order to eliminate the skid mark which is a disturbance of 0.2 [Hz] to 1.0 [Hz], s = in order to make 20.LOG | G ₁ | at 0.2 [Hz] to 1.0 [Hz] as small as possible. 0.0
At [rad / sec], we usually want to design 20 · LOG | G ₁ | to be −∞ [dB], but it is extremely difficult to realize.

Here, LOG means common logarithm, and | G ₁ |
Means the absolute value of G ₁ . Therefore, if | G ₁ | becomes zero, 20 · LOG | G ₁ | becomes −∞ [dB].

In the following, when the conventional control method is used, 20
The reason why it is difficult to design LOG | G ₁ | to be −∞ [dB] is explained by the characteristics of 20 ・ LOG | G ₁ | and 20 ・ LOG | G ₂ |, and the horizontal axis is [Hz]. 11 and 12 where the logarithmic scale is taken as the vertical axis [dB] and the product thickness graph using the conventional control method is plotted on the horizontal axis as time [se
FIG. 13 and FIG. 1 in which the vertical axis represents plate thickness [mm].
It will be described in detail with reference to FIG.

First, a Mill Modulus Control type AG
The case of C will be described.

At s = 0.0 [rad / sec], 20 · LOG | G
_{In order for 1} | to be −∞ [dB], the above equation (11) G ₁ = W · [T ₁ s + (1-α)] / T ₁ s + (1-W · α)・ From (11), α = 1.0 is required (assuming that a high-speed reduction mechanism that is effective for skid mark reduction like a hydraulic reduction mechanism is used), but if α = 1.0, then T ₁ << 1.0 Therefore, as shown by the solid line in FIG. 11, not only the frequency band of the skid mark (0.2 [Hz] to 1.0 [Hz]) but also the frequency band of the roll eccentric disturbance (4.0 [Hz] to 10.0 [ Hz]), 20 · LOG | G ₁ | may be in the vicinity of −40 to −20 [dB], and from the relationship of the above equation (6) G ₁ + G ₂ = 1 (6) Inevitably, 20 · LOG | G ₂ | is difficult to lower to −40 [dB] in the frequency band of roll eccentricity disturbance (4.0 [Hz] to 10.0 [Hz]). Only the characteristics shown by the solid line are obtained.

As a result, when the automatic plate thickness deviation control system I is used, roll eccentricity disturbance (ΔS _e ) is markedly printed on the rolled material as shown in FIG. μ
Therefore, a plate thickness deviation of about [m] will occur.

On the contrary, when the tuning factor α is set to 0.7 or 0.5, as shown in FIG. 14, the influence of the roll eccentricity on the delivery side plate thickness deviation (Δh) disappears, but it is low. In the frequency range, the G ₁ gain cannot be reduced and the entrance side plate thickness deviation (ΔH) such as skid mark remains in the rolled material, resulting in a plate thickness deviation of about 100 [μm].

It is desirable that the characteristics of 20LOG | G ₁ | and 20LOG | G ₂ | shown by dotted lines in FIGS.

Next, the case of the Gauge Meter type AGC will be described.

Also in this case, in order to bring 20 · LOG | G ₁ | close to −∞ [dB] at s = 0.0 [rad / sec],
Than previously described (18) G ₁ = W ^{_{[T 1 · s 2 + s +}} G (1-α) ] / ^{_{[T 1 · s 2 + s +}} G (1-α · W) ] · · · (18), alpha = 1.0 Is necessary (assuming that a high-speed rolling-down mechanism such as a hydraulic rolling-down mechanism that is effective for reducing skid marks is used), but if α = 1.0, then T ₁ << 1.0, so the solid line in FIG. As shown, not only the skid mark frequency band (0.2 [Hz] to 1.0 [Hz]),
Frequency band of roll eccentric disturbance (4.0 [Hz] to 10.0 [H
z)), 20 · LOG | G ₁ | may be in the vicinity of −40 to −20 [dB], and from the relationship of the above equation (6) G ₁ + G ₂ = 1 (6). Inevitably, 20 · LOG | G ₂ | is difficult to lower to −40 [dB] in the frequency band of roll eccentricity disturbance (4.0 [Hz] to 10.0 [Hz]). Only the characteristics shown by the solid line are obtained. As a result, even if the automatic plate thickness deviation control system I is used, as shown in FIG. 13, roll eccentric disturbance (ΔS _e ) is markedly printed on the rolled material, and 70 [μm] Therefore, a plate thickness deviation will occur.

On the contrary, when the tuning factor α is set to 0.7 or 0.5, as shown in FIG. 14, the influence of roll eccentricity on the outlet side plate thickness deviation (Δh) disappears, but it is low. The G ₁ gain cannot be reduced in the frequency range, and the inlet side plate thickness deviation (ΔH) such as skid mark remains in the rolled material, resulting in a plate thickness deviation of about 100 μm.

In any case, it is desirable that the characteristics of 20LOG | G ₁ | and 20LOG | G ₂ | shown by the dotted lines in FIGS. 11 and 12 are desirable.

In other words, in the conventional plate thickness deviation control method, 20 · LOG | G ₁ | of s = 0.0 [Rad / sec] is set to −∞ [dB].
If the tuning factor α is brought closer to 1.0 in order to bring it closer to 20, then 20 · LOG | G ₂ | will be increased and the roll eccentricity (Δ
S _e ) will facilitate printing on the rolled material, and conversely, when the tuning factor α is set to 0.7 or 0.5, the influence of roll eccentricity on the outlet side plate thickness deviation (Δh) However, the skid mark frequency band (0.
In the range of 2 [Hz] to 1.0 [Hz], 20 · LOG | G ₁ | cannot be reduced, and the inlet plate thickness deviation (ΔH) such as skid mark remains in the rolled material.

As described above, in the conventional plate thickness deviation control method, if the entrance side plate thickness deviation (ΔH) such as skid mark is to be removed, the roll eccentricity (ΔS _e ) cannot be removed. When trying to remove the roll eccentricity (ΔS _e ),
Incoming plate thickness deviation (ΔH) such as skid mark cannot be removed.

The control method of the present invention, b - removing Le eccentricity ([Delta] S _e), and, b - at the same time removing the Le and eccentricity ([Delta] S _e) and thickness at entrance side deviations ([Delta] H), for It is intended to provide a plate thickness deviation disturbance removal control method.

[0046]

The method of the present invention has the following features.

At the time of rolling the steel sheet, the signal (ΔP [kgw]) indicating the rolling load deviation from the rolling load meter and the signal (ΔS [mm]) indicating the operation amount of the rolling-down mechanism from the rolling-down position detector are input, and the calculation result is obtained. Of the rolling mill rigidity coefficient (M
[Kgw / mm]) and tuning factor (α [---])
, Plasticity coefficient of rolled material (Q [kgw / mm]), integral constant (G [1 / sec]), Laplace operator (s [1 / sec])
With, ΔF =-[Δs + (α / M) ・ ΔP] ・ [(M + Q) / M] ・ G / s (20) Calculate ΔF ([mm]) by The operation command amount (Δu [mm]) is calculated from ΔF [mm] and the reduction reference (ΔR _r [mm]) based on the equation Δu = ΔR _r −ΔF (21).

[0048]

The present invention will be described in detail below with reference to the drawings.

FIG. 1 is a block diagram for explaining the principle of the plate thickness disturbance removal control method of the present invention. The automatic internal plate thickness deviation control system I shown in FIG. 1 is hereinafter referred to as an improved automatic internal plate thickness deviation control system. The present invention uses the improved automatic plate thickness deviation control system to bring 20 · LOG | G ₁ | in the frequency band of 0.2 [Hz] to 1.0 [Hz] close to −40 to −20 [dB]. 20 ・ LOG | in the frequency band of 4.0 [Hz] to 10.0 [Hz]
By reducing G ₂ | to near -40 [dB],
Guarantee to reduce skid mark disturbance and roll eccentric disturbance simultaneously.

20 in the frequency band of 0.2 [Hz] to 1.0 [Hz]
・ Reduces LOG | G ₁ | to near -40 [dB], 4.0 [Hz] ~
20 · LOG | G ₂ | in the frequency band of 10.0 [Hz] is -20 [d
B] In order to reduce it to near 20, LOG | G ₁ |
A frequency characteristic as shown in, 20 · LOG | G ₂ | in as is given the characteristics as shown in FIG. 3, C _{i (i} = 1~
3) to provide _{C 1 = 1 ··· (22)} C 2 = α / M ··· (23) C 3 = G / (1-W) · s ··· (24).

Further, G _R can be expressed as G _R = 1 / (1 + T ₁ s) (25) when a high-speed reduction mechanism such as a hydraulic reduction mechanism is used.

However, T ₁ : time constant of the rolling-down mechanism [sec] s: Laplace operator [1 / sec] When the Laplace operator is written as 1 / s,

[0053]

[Equation 2]

Means to carry out.

The reason why C _i (i = 1 to 3) is given by the equations (22) to (24) will be described in detail below.

The transfer characteristic G ₁ from the entrance side plate thickness deviation (ΔH) to the exit side plate thickness deviation (Δh) and the roll eccentricity (ΔS _e ).
To calculate the transfer characteristic G ₂ to side thickness deviation (Delta] h) out, (5) to (22) specifically substituting from the equation (25) equation, G ₁ = W · [T ₁ · s ² + s + G · (1-α) / (1-W)] / [T ₁ · s ² + s + G · (1-W · α) / (1-W)] (26) G ₂ = (1 -W) · obtain ^{_{[T 1 · s 2 + s +}} G / (1-W) ] / ^{_{[T 1 · s 2 + s +}} G · (1-W · α) / (1-W) ] .. (27).

20. To set LOG | G ₁ | to -∞ [dB],
α = 1 is sufficient. In this _{case, G 1 = (W · T} 1 · s 2) + (W · s) / (T 1 · s 2) + s + G ··· (28) G 2 = (1-W) · [T ₁ · s ^{2 + s + G / (1} -W) ] / can be expressed as ^{_{(T 1 · s 2 + s}} + G) ··· (29).

Here, in order to draw the Bode diagrams of the equations (28) and (29), the equations (28) and (29) are approximated.

Now, considering that T ₁ is the time constant of the rolling-down mechanism and T ₁ << ₁ when the hydraulic rolling-down mechanism is used, the quadratic term of the Laplace operator s can be almost ignored. Therefore, it is considered that G ₁ = (W · s) / (s + G) ... (30) G ₂ = (1-W) · [s + G / (1-W)] / (s + G) ... (31) You may. Here, the poles of the equations (30) and (31) are s = G.

At this time, the zero point of G ₂ is -G (1-W)
That is, − [(M + Q) / M] · G (32). In addition, considering that G / W ≧ G ... (33), from equations (30) and (31),
-LOG | G ₁ | and 20-LOG | G ₂ | show that Bode diagrams having the frequency characteristics shown in FIGS. 2 and 3 are obtained, respectively.

The procedure for determining the value of G will be described below.

The frequency band of the entrance side plate thickness deviation (ΔH) (hereinafter referred to as frequency band 1) is calculated from the interval of the skid of the heating furnace and the strip passing speed of the rolled material, and the frequency at which the roll is eccentric (hereinafter, The frequency band 2) is determined from the diameter of the pack-up roll and the threading speed.

Frequencies greater than the upper limit of frequency band 1 and not included in frequency band 2 are represented by [rad / sec], and G
[rad / sec]

[0064]

[Examples] The specifications of a hot rolling mill for steel plates and steel plates are, for example, M = 500,000 [kgW / mm] (34) Q = 2,000,000 [kgW / mm] (35) T ₁ = 1/240 [sec / rad] (36), this system was adopted.

The inlet side plate thickness deviation disturbance (ΔH) is 0.2 [Hz] to
In the 0.4 [Hz] band, roll eccentricity disturbance is 4.0 [Hz] ~
Since it is in the band of 10.0 [Hz], the frequency separating them is
It was set to 0.55 [Hz] (3.5 [rad / sec]).

G = 3.5 [rad / sec] (37) In order to remove the inlet side plate thickness deviation disturbance (ΔH), α = 1 (38).

At this time, as shown in FIG. 4, 0.2 [Hz]
G ₁ is reduced in the band of up to 0.4 [Hz], and as shown in FIG. 5, G ₂ is reduced in the band of 4.0 [Hz] to 10.0 [Hz]. , 0.2
Skidmark disturbance in the range of [Hz] to 0.4 [Hz] and 4.0
It is guaranteed that the roll eccentric disturbance in the band [Hz] to 10.0 [Hz] will be removed at the same time.

Rolling load deviation: ΔP = 40,000 [KgW] (39) Rolling position deviation: ΔS = 0.07000 [mm] (40) from time 0.0 seconds to 0.1 seconds. Rolling reference: ΔR _{When r} = 0.0300 [mm] (41) is given, 0.1 second later, the output of the automatic plate thickness deviation control system: ΔF = [0.0700 + {(1.0) / (500,000)} x 40,000 ] [[500,000 + 2,000,000) / (500,000)] 3.5.0.1 = 0.2625 ... (42) Therefore, the reduction mechanism operation command amount (Δu [mm]) is Δu = 0.0300−0.2625 = −0.2325 .. (43) is calculated and sent to the reduction mechanism.

As shown in FIG. 6, the deviation of the product plate thickness is 50.
[Μm] or less, which is about 1/2 or less of the plate thickness deviation (about 100 [μm]) obtained by the conventional method shown in FIG.

[0070]

[Effect] By introducing the improved automatic internal plate thickness control system of the present invention, (1) it is possible to simultaneously remove a relatively close inlet side thickness deviation disturbance and a roll eccentricity disturbance, (2) The accuracy can be improved, and (3) the product yield can be improved.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of an automatic internal plate thickness deviation control system for carrying out the present invention in one aspect.

FIG. 2 is a graph showing a gain changing characteristic which is an object of the present invention, showing 20 · LOG│G ₁ │.

FIG. 3 is a graph showing a gain changing characteristic intended by the present invention, showing a value of 20 · LOG│G ₂ │.

FIG. 4 is a graph showing a gain changing characteristic according to an embodiment of the present invention, showing 20 · LOG│G ₁ │.

FIG. 5 is a graph showing a gain changing characteristic according to an embodiment of the present invention, showing 20 · LOG│G ₂ │.

FIG. 6 is a graph showing a product plate thickness according to an embodiment of the present invention.

FIG. 7 is a block diagram showing a conventional rolling system.

8 is a conventional automatic internal plate thickness deviation control system 6 shown in FIG.
FIG. 3 is a block diagram showing the configuration of FIG.

9 is a block diagram showing an example of specific setting values in each block in block I shown in FIG. 8. FIG.

10 is a block diagram showing another example of specific setting values in each block in block I shown in FIG. 8. FIG.

FIG. 11 is a graph showing a gain changing characteristic according to a conventional method, showing a value of 20 · LOG│G ₁ │.

FIG. 12 is a graph showing a change characteristic of gain by a conventional method, showing 20 · LOG│G ₂ │.

FIG. 13 is a graph showing a product plate thickness according to one conventional method.

FIG. 14 is a graph showing a product plate thickness according to another conventional method.

[Explanation of symbols]

1: Rolling mill 2: Rolled material 3: Rolling position detector 4: Rolling load meter 5: Rolling down mechanism 6, I: Automatic plate thickness deviation control system

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Shuichi Niu 1 Nishinosu, Oita-shi, Oita Steel Co., Ltd. Oita Works

Claims (1)

[Claims] 1. When rolling a steel sheet, a signal indicating a rolling load deviation from a rolling load meter and a signal indicating a rolling position deviation from a rolling position detector are input, and a calculation result is output to a rolling mechanism to determine the thickness of the steel sheet. In the automatic plate thickness deviation control system to control, rolling load deviation ΔP [kgw] and rolling position deviation ΔS [mm]
, Rolling mill rigidity coefficient M [kgw / mm], tuning factor α, rolled material plasticity coefficient Q [kgw / mm], and integral constant G
[1 / sec] and Laplace operator s [1 / sec]), ΔF = − [Δs + (α / M) · ΔP] · [(M + Q) / M] · G / s ( 1) ΔF [mm] is calculated by the following calculation, and the reduction system mechanism operation command amount Δu [mm] is compared with ΔF [mm] and the reduction reference (Δ
R _r [mm]) is calculated based on the equation Δu = ΔR _r −ΔF (2).