BACKGROUND OF THE INVENTION
The invention relates to a rolling control apparatus, a rolling control method, and
a rolling control program and, more particularly, to thickness control in a tandem rolling.
There is such a tandem rolling mill that by arranging a plurality of rolling stands,
5 a strip is rolled a plurality of number of times to thereby obtain a desired thickness. In such a
tandem rolling mill, there is a case where such mass-flow automatic gauge control that a strip
speed of a strip which is rolled is detected, a thickness estimation value just under the rolling
mill (hereinbelow, referred to as "mass-flow gauge") is obtained, and thickness control is made
is performed.
10 In the case of applying the mass-flow automatic gauge control in a continuous
rolling mill in which a rolling is continuously executed by a plurality of rolling stands, it is
necessary to provide expensive thickness gauge and strip speed detector or strip velocity meter
for each stand, and high costs for initial investment and maintenance are required to provide
them. Therefore, a method whereby a mass-flow thickness is estimated by a model or an
15 estimating calculation while the thickness gauges and strip speed detectors are omitted as many
as possible is used.
In order to compensate an error of the mass-flow gauge and assure a thickness
accuracy on the delivery side of the final stand, the following method has been proposed (for
example, refer to JP-A-2009-113100): that is, by using a rolling force and a rolling position
20 measured by a load cell disposed to one stand, a gauge-meter thickness or gauge-meter-gauge
just under the one stand is obtained by a gauge meter, a strip speed on the entry side of the
rolling mill is detected by a bridle roll disposed on the entry side of the rolling mill, a strip
thickness on the entry side of the rolling mill is measured by a thickness gauge disposed on the
entry side of the rolling mill, and a strip speed on the delivery side of the rolling mill is
25 calculated from the strip speed on the entry side of the rolling mill, the thickness on the entry
side of the rolling mill, and the gauge-meter thickness of the first rolling stand.
SUMMARY OF THE INVENTION
The expensive load cell is necessary for the calculation of the gauge-meter
30 thickness as disclosed in JP-A-2009-113100. In recent years, a demand for removing the load
cell in order to reduce the initial cost, improve maintenance performance, and reduce the
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maintenance costs has been increasing.
One of advantages of use of the mass-flow thickness is that such a calculation can
be realized by the strip speed detector which is relatively cheaper than the thickness gauge.
However, in the strip speed detector as well, its costs and maintenance performance cannot be
5 ignored and the request to reduce the number of strip speed detectors still remains.
In the case of reducing the number of strip speed detectors as to a portion in
which the strip speed cannot be actually detected the strip speed on the delivery side of the
rolling mill can be calculated fi^om a roll speed and a forward strip ratio of the rolling mill.
However, according to such a method, in a situation where the forward strip ratio changes at the
10 time of acceleration, deceleration, or the like of the rolling mill, an error of the mass-flow gauge
may occur and a thickness accuracy cannot be assured.
The invention is made to solve the foregoing problems and it is an object of the
invention that in the case of making mass-flow automatic gauge control in a tandem rolling mill,
strip speed detectors are omitted as many as possible by an arithmetic operation of a delivery
15 side strip speed by a forward slip ratio and a deterioration in thickness accuracy due to an error
of the forward slip ratio is prevented.
According to an aspect of the invention, there is provided a rolling control
apparatus for controlling a tandem rolling mill which rolls a strip by a plurality of roll pairs,
comprising:
20 a forward slip ratio obtaining unit for obtaining a forward slip ratio in a first
rolling stand corresponding to a condition regarding the rolling of the strip which is being rolled
from information in which the condition regarding the rolling of the strip and the forward slip
ratio have been associated;
a first roll strip speed calculating unit for calculating a conveying speed of the
25 strip on a delivery side of the first rolling stand on the basis of a roll speed of the first rolling
stand and the obtained forward slip ratio;
a first roll thickness calculating unit for calculating a thickness of the strip on the
delivery side of the first rolling stand on the basis of a thickness of the strip on the entry side of
the first rolling stand, a conveying speed of the strip detected on the entry side of the first rolling
30 stand, and the calculated conveying speed of the strip on the delivery side of the first rolling
stand;
a forward slip ratio error calculating unit for calculating an error of the obtained
forward slip ratio on the basis of a difference between the thickness of the strip detected on the
delivery side of the first rolling stand and the calculated thickness of the strip on the delivery side
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of the first rolling stand;
a second rolling stand thickness calculating unit for calculating a thickness of the
strip on a delivery side of a second rolling stand arranged next to the first rolling stand on the
basis of the thickness of the strip detected on the delivery side of the first rolling stand, the
5 calculated conveying speed of the strip on the delivery side of the first rolling stand, and a
conveying speed of the strip detected on the delivery side of the second rolling stand; and
a second roll thickness correcting unit for correcting the calculated thickness of
the strip on the delivery side of the second rolling stand on the basis of the calculated error of the
forward slip ratio.
10 According to another aspect of the invention, there is provided a rolling control
method of controlling a tandem rolling mill which rolls a strip by a plurality of roll pairs,
comprising the steps of
obtaining a forward slip ratio in a first rolling stand corresponding to a condition
regarding the rolling of the strip which is being rolled fi"om information in which the condition
15 regarding the rolling of the strip and the forward slip ratio have been associated;
calculating a conveying speed of the strip on a delivery side of the first rolling
stand on the basis of a roll speed of the first rolling stand and the obtained forward slip ratio;
calculating a thickness of the strip on the delivery side of the first rolling stand on
the basis of a thickness of the strip on the entry side of the first rolling stand, a conveying speed
20 of the strip detected on the entry side of the first rolling stand, and the calculated conveying
speed of the strip on the delivery side of the first rolling stand;
calculating an error of the obtained forward slip ratio on the basis of a difference
between the thickness of the strip detected on the delivery side of the first rolling stand and the
calculated thickness of the strip on the delivery side of the first rolling stand;
25 calculating a thickness of the strip on a delivery side of a second rolling stand
arranged next to the first rolling stand on the basis of the thickness of the strip detected on the
delivery side of the first rolling stand, the calculated conveying speed of the strip on the delivery
side of the first rolling stand, and a conveying speed of the strip detected on the delivery side of
the second rolling stand; and
30 correcting the calculated thickness of the strip on the delivery side of the second
rolling stand on the basis of the calculated error of the forward slip ratio.
According to still another aspect of the invention, there is provided a rolling
control program for controlling a tandem rolling mill which rolls a strip by a plurality of roll
pairs, wherein the program allows an information processing apparatus to execute the steps of
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obtaining a forward slip ratio in a first rolling stand corresponding to a condition
regarding the rolling of the strip which is being rolled from information in which the condition
regarding the rolling of the strip and the forward slip ratio have been associated;
calculating a conveying speed of the strip on a delivery side of the first rolling
5 stand on the basis of a roll speed of the first rolling stand and the obtained forward slip ratio;
calculating a thickness of the strip on the delivery side of the first rolling stand on
the basis of a thickness of the strip on the entry side of the first rolling stand, a conveying speed
of the strip detected on the entry side of the first rolling stand, and the calculated conveying
speed of the strip on the delivery side of the first rolling stand;
10 calculating an error of the obtained forward slip ratio on the basis of a difference
between the thickness of the strip detected on the delivery side of the first rolling stand and the
calculated thickness of the strip on the delivery side of the first rolling stand;
calculating a thickness of the strip on a delivery side of a second rolling stand
arranged next to the first rolling stand on the basis of the thickness of the strip detected on the
15 delivery side of the first rolling stand, the calculated conveying speed of the strip on the delivery
side of the first rolling stand, and a conveying speed of the strip detected on the delivery side of
the second rolling stand; and
correcting the calculated thickness of the strip on the delivery side of the second
rolling stand on the basis of the calculated error of the forward slip ratio.
20 According to the invention, in the case of making the mass-flow automatic gauge
control in the tandem rolling mill, the strip speed detectors are omitted as many as possible by
the arithmetic operation of the delivery side strip speed by the forward slip ratio and the
deterioration in thickness accuracy due to the error of the forward slip ratio can be prevented.
Other objects, features and advantages of the invention will become apparent
25 from the following description of the embodiments of the invention taken in conjunction with the
accompanying drawings.
BRffiF DESCRIPTION OF THE DRAWINGS
Fig. 1 is a diagram showing a whole construction of a rolling mill and a rolling
30 control apparatus according to an embodiment of the invention;
Fig. 2 is a diagram showing an example of a forward slip ratio DB (data base)
according to the embodiment of the invention;
Fig. 3 is a flowchart shoving the learning operation of a forward slip ratio
according to the embodiment of the invention; and
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Fig. 4 is a diagram showing a hardware construction of the rolling control
apparatus according to the embodiment of the invention.
DESCRIPTION OF THE EMBODIMENTS
5 In an embodiment, in a tandem rolling mill including three rolling stands, a
rolling system in which a thickness gauge is provided on each of the entry side and the delivery
side of the head rolling stand, a strip speed detector or strip velocity meter is provided between
the stands in which a thickness gauge is not provided, and the mass-flow automatic gauge
control is performed will be described. Fig. 1 is a diagram showing a whole construction of the
10 rolling system according to the embodiment. As shown in Fig. 1, the rolling system according
to the embodiment is a system as a continuous rolling mill having three or more rolling stands
and the control by a mass-flow thickness correction is executed.
As shown in Fig. 1, a rolling mill entry side strip speed detecting unit 10 to detect
a strip speed of a strip (material to be rolled) 1 is provided on the entry side of a first rolling
15 stand 11 arranged at the head among the three rolling stands such as first rolling stand 11, second
rolling stand 12, and third rolling stand 13 in the progressing direction of the strip 1. The
rolling mill entry side strip speed detecting unit 10 is constructed by a bridle roll, a steering roll,
a deflector roll, or the like. A speed of the strip 1 on the entry side of the rolling mill is directly
detected or is indirectly detected through the roll.
20 A first rolling stand entry side thickness gauge 21 and a first rolling stand delivery
side thickness gauge 22 are provided on the entry side and the delivery side of the first rolling
stand 11, respectively. Thus, a thickness of the strip 1 on the entry side of the first rolling stand
and a thickness of the strip 1 on the delivery side of the first rolling stand are measured,
respectively. A load cell of the first rolling stand 11 is unnecessary and is omitted.
25 A second rolling stand delivery side strip speed detector 23 and a third rolling
stand delivery side strip speed detector 24 are provided on the delivery side of the second rolling
stand 12 and the delivery side of the third rolling stand 13, respectively. Thus, a strip speed
between the second rolling stand 12 and the third rolling stand 13 and a strip speed on the
delivery side of the third rolling stand 13 are directly measured.
30 A rolling control apparatus 100 controls such rolling stands and a plurality of
detectors, thereby controlling the rolling operation of the strip. A transport processing unit 50
delays an actual value of the thickness on the entry side of the rolling mill which was measured
by the first rolling stand entry side thickness gauge 21 in accordance with a movement distance
of the strip 1 and inputs a delayed value to a first rolling stand delivery side strip speed
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arithmetic operating unit 32 as an entry side thickness Hi just under the first rolling stand. A
first rolling stand forward slip ratio prediction arithmetic operating unit 31 obtains a prediction
forward slip ratio of the first rolling stand 11 with reference to a forward slip ratio DB 41. That
is, the first rolling stand forward slip ratio prediction arithmetic operating unit 31 functions as a
5 forward slip ratio obtaining unit.
The first rolling stand delivery side strip speed arithmetic operating unit 32
obtains a strip speed Vid on the delivery side of the first rolling stand 11 by the following
equation (1) on the basis of a roll speed VR and a forward slip ratio prediction value fi of the
first rolling stand 11. That is, the first rolling stand delivery side strip speed arithmetic
10 operating unit 32 functions as a first roll strip speed calculating unit.
Vid=VR(l+f,) (1)
A transport processing unit 52 delays an actual value of the thickness on the
delivery side of the first rolling stand 11 which was measured by the first rolling stand delivery
side thickness gauge 22, that is, an actual value of the thickness on the entry side of the second
15 rolling stand in accordance with a movement distance of the strip on the delivery side of the first
rolling stand, thereby obtaining a thickness hi on the entry side of the second rolling stand just
under the second rolling stand.
A second rolling stand mass-flow thickness arithmetic operating unit 34 obtains a
second rolling stand mass-flow estimation thickness hnif2 by the following equation (2) on the
20 basis of the following items. That is, the second rolling stand mass-flow thickness arithmetic
operating unit 34 functions as a second roll thickness calculating unit.
Vid
where,
hi: Thickness on the entry side of the second rolling stand just under the second rolling stand
25 Vid: Strip speed on the delivery side of the first rolling stand
V2d: Strip speed on the delivery side of the second rolling stand
Vid obtained by the equation (1) contains an error according to an error
component of the forward slip ratio prediction value fi of the first rolling stand. Therefore, the
second rolling stand mass-flow estimation thickness hmf2 obtained by the equation (2) also
30 contains the error according to the error component of the forward slip ratio prediction value fi
of the first rolling stand 11.
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A first rolling stand mass-flow thickness arithmetic operating unit 33 obtains a
first rolling stand mass-flow estimation thickness hmfi by the following equation (3) on the basis
of the following items. That is, the first rolling stand mass-flow thickness arithmetic operating
unit 33 functions as a first roll thickness calculating unit.
Ve
h»ft= H. (3)
VR(1 + f i)
5 where,
Vid: Strip speed on the delivery side of the first rolling stand obtained by the equation (1)
Ve: Strip speed on the entry side of the first rolling stand detected by the rolling mill
entry side strip speed detecting unit 10
Hi: Thickness on the entry side just under the first rolling stand
10 The first rolling stand mass-flow estimation thickness hmfi calculated by the first
rolling stand mass-flow thickness arithmetic operating unit 33 is delayed by a transport
processing unit 51 in accordance with a movement distance of the strip within a range from the
first rolling stand 11 to the first rolling stand delivery side thickness gauge 22 and, thereafter, is
inputted to a first rolling stand forward slip ratio error arithmetic operating unit 35. Therefore,
15 the first rolling stand mass-flow estimation thickness hmn just under the first rolling stand
delivery side thickness gauge 22 is inputted to the first rolling stand forward slip ratio error
arithmetic operating unit 35.
The first rolling stand forward slip ratio error arithmetic operating unit 35
compares an actual value hi of the thickness on the delivery side of the first rolling stand which
20 was measured by the first rolling stand delivery side thickness gauge 22 and the first rolling
stand mass-flow estimation thickness hmfi which was delayed and inputted by the transport
processing unit 51. As a result of the comparison by the first rolling stand forward slip ratio
error arithmetic operating unit 35, if an error occurs between the first rolling stand mass-flow
estimation thickness hmn and the first rolling stand delivery side thickness actual value hi, the
25 error can be determined as an error of the first rolling stand forward slip ratio fi used in the massflow
thickness calculation as mentioned above. Therefore, the first rolling stand forward slip
ratio error arithmetic operating unit 35 obtains an error Afi of the first rolling stand forward slip
ratio by the following equation (4). That is, the first rolling stand forward slip ratio error
arithmetic operating unit 35 functions as a forward slip ratio error calculating unit.
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2Jf, = ( l +fi) 1 (4)
Since the error of the mass-flow estimation thickness hmfi of the first rolling stand
11 is an error of the forward slip ratio prediction value, it is an error of a prediction value of the
first rolling stand delivery side strip speed. An error has also occurred in the second rolling
5 stand mass-flow estimation thickness hmf2 When the strip rolled by the first rolling stand 11
has reached the first rolling stand delivery side thickness gauge 22, the strip rolled by the second
rolling stand is located between the second rolling stand and the third rolling stand.
Assuming that a distance between the first rolling stand 11 and the first rolling
stand delivery side thickness gauge 22 is equal to LI, a distance L2 by which the strip rolled just
10 under the second rolling stand moves for a period of time during which the strip rolled just under
the first rolling stand reaches the first rolling stand delivery side thickness gauge 22 can be
obtained by the following equation (5).
L2 = L1- — ^ (5)
A transport processing unit 53 delays the mass-flow estimation thickness hmf2 just
15 under the second rolling stand by the distance L2 obtained by the equation (5) in accordance
with the speed of the strip and inputs a delayed value to a second rolling stand mass-flow
thickness error compensating unit 36. If the error Afi of the first rolling stand forward slip ratio
obtained by the foregoing equation (4) is not equal to 0, the second rolling stand mass-flow
thickness error compensating unit 36 obtains a value hmficomp after the correction of the second
20 rolling stand mass-flow estimation thickness hmfz by the following equation (6). Thus, the error
component of the first rolling stand forward slip ratio fi can be cancelled. That is, the second
rolling stand mass-flow thickness error compensating unit 36 functions as a second roll thickness
correcting unit.
"1
25 A transport processing unit 54 delays the mass-flow estimation thickness hmfzcomp
after the correction in accordance with the movement distance of the strip and inputs a delayed
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value to a third rolling stand mass-flow thickness arithmetic operating unit 37 as an entry side
thickness just under the third rolling stand.
Since the strip speed detectors are disposed on both of the entry side and the
delivery side of the third rolling stand 13, the actual reduction of the third rolling stand 13 can be
5 accurately obtained. A thickness on the entry side of the third rolling stand 13 can be also
accurately obtained by compensating the error of the mass-flow estimation thickness.
Therefore, the third rolling stand mass-flow thickness arithmetic operating unit 37 can calculate
the accurate mass-flow thickness. Even in the case where a rolling stand continues further at
downstream side of the third rolling stand 13, if the strip speed detectors are disposed on both of
10 the entry side and the delivery side in a manner similar to the third rolling stand 13, the accurate
mass-flow thickness can be obtained.
Further, since the error Afi of the forward slip ratio prediction value can be
obtained at a stage in which the strip 1 rolled by the first rolling stand 11 has reached the first
rolling stand delivery side thickness gauge 22, in order to minimize the error, it is desirable to
15 adaptively correct the forward slip ratio by learning the forward slip ratio of the first rolling
stand 11. A learning method of the forward slip ratio will be described hereinbelow.
As shown in Fig. 2, the forward slip ratio DB 41 includes a table in which the
forward slip ratios which are predicted in accordance with the strip thickness, strip width, steel
grade, and roll speed of the strip have been stored. The first rolling stand forward slip ratio
20 prediction arithmetic operating unit 31 obtains the forward slip ratio prediction value in
accordance with the roll speed of the first rolling stand 11 and other conditions with reference to
such a table and inputs to the first rolling stand delivery side strip speed arithmetic operating unit
32.
A first rolling stand forward slip ratio adaptive correcting unit 40 learns parameter
25 table values corresponding to a rolling state (strip thickness, strip width, steel grade, roll speed)
on the basis of the error Afi of the forward slip ratio prediction value obtained by the first rolling
stand forward slip ratio error arithmetic operating unit 35 so as to minimize such an error That
is, the first rolling stand forward slip ratio adaptive correcting unit 40 fiinctions as a forward slip
ratio correcting unit. Fig. 3 is a flowchart showing the learning operation of the forward slip
30 ratio according to the embodiment.
As shown in Fig. 3, first, the first rolling stand forward slip ratio error arithmetic
operating unit 35 obtains an error Af (Afi) of the prediction forward slip ratio and the first rolling
stand forward slip ratio adaptive correcting unit 40 obtains a value of the prediction forward slip
ratio error (S301). The first rolling stand forward slip ratio adaptive correcting unit 40
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discriminates whether or not the prediction forward slip ratio error lies within an upper/lower
limit range with reference to a preset upper/lower limit table (S302). As a result of the
discrimination of S302, if it is out of the upper/lower limit range (NO in S302), it is regarded that
the data is abnormal data, and the process is interrupted.
5 As a result of the discrimination of S3 02, if it lies within the upper/lower limit
range (YES in S302), the first rolling stand forward slip ratio adaptive correcting unit 40 updates
the forward slip ratio table values of the thickness, width, steel grade, and roll speed on the basis
of the value of the error obtained in S301, thereby learning by the following equation (7).
K H. W , S a Speed) = f(KW,SG, Speed ) + a • ^fi ( 7)
10 In the equation (7), a denotes a learning coefficient and is a constant of 1.0 or
less. That is, the first rolling stand forward slip ratio adaptive correcting unit 40 corrects the
forward slip ratio by applying a part of the calculated forward slip ratio error to the forward slip
ratio stored in the forward slip ratio DB 41. By such a process, the excessive correction can be
prevented.
15 After that, the first rolling stand forward slip ratio adaptive correcting unit 40
performs an upper/lower limit value restriction of the forward slip ratio which was adaptively
corrected in S303 (S304) and the process is finished. In S304, if the forward slip ratio after the
updating exceeds the upper limit value, the first rolling stand forward slip ratio adaptive
correcting unit 40 sets the forward slip ratio after the updating to the upper limit value, and if the
20 forward slip ratio after the updating is lower than the lower limit value, the first rolling stand
forward slip ratio adaptive correcting unit 40 sets the forward slip ratio after the updating to the
lower limit value.
As mentioned above, in the rolling system according to the embodiment, by
adaptively correcting the first rolling stand forward slip ratio prediction value during the rolling,
25 the error of the forward slip ratio prediction value can be also minimized. Thus, a calculation
accuracy of the mass-flow thickness arithmetic operation is improved and a high accuracy of the
mass-flow automatic gauge control can be realized.
The foregoing embodiment has been described as an example with respect to the
case where the invention is applied to the rolling stands within a range from the first rolling stand
30 11 to the third rolling stand 13 in the rolling system including three rolling stands. However,
the invention is not limited to the application to the first to the third rolling stands but can be also
applied to the rolling stands within a range from the Nth rolling stand to the (N+2)th rolling
stand (N is an integer) so long as they have a construction similar to that mentioned above.
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The rolling control apparatus 100 as shown in Fig. 1 is realized by a combination
of software and hardware. The hardware to realize the flmctions of the rolling control
apparatus 100 according to the embodiment will now be described with reference to Fig. 4.
Fig. 4 is a block diagram showing a hardware construction of an information processing
5 apparatus constructing the rolling control apparatus 100 according to the embodiment. As
shown in Fig. 4, the rolling control apparatus 100 according to the embodiment has a
construction similar to that of an information processing terminal such as a general server
computer, a PC (Personal Computer), or the like.
That is, in the rolling control apparatus 100 according to the embodiment, a CPU
10 (Central Processing Unit) 101, a RAM (Random Access Memory) 102, a ROM (Read Only
Memory) 103, an HDD (Hard Disk Drive) 104, and an I/F (interface) 105 are connected through
a bus 108. An LCD (Liquid Crystal Display) 106 and an operation unit 107 are connected to
the I/F 105.
The CPU 101 is an arithmetic operating unit and controls the whole operation of
15 the rolling control apparatus 100. The RAM 102 is a volatile storage medium in/from which
information can be written and read out at a high speed. The RAM 102 is used as a work area
at the time when the CPU 101 processes information. The ROM 103 is a read-only non-volatile
storage medium. Programs such as firmware and the like have been stored in the ROM 103.
The HDD 104 is a non-volatile storage medium in/from which information can be
20 written and read out. An OS (Operating System), various kinds of control programs,
application • programs, and the like have been stored in the HDD 104. The I/F 105 connects the
bus 108 and various kinds of hardware, a network, and the like and controls them. The I/F 105
is also used as an interface for allowing each apparatus to transmit and receive information or
input information to the rolling mill.
25 The LCD 106 is a display device as a visual user interface for allowing the
operator to confirm a state of the rolling control apparatus 100. The operation unit 107 is a user
interface such as keyboard, mouse, or the like for allowing the operator to input information to
the rolling control apparatus 100. In such a hardware construction, a program stored in the
ROM 103 or HDD 104 or a recording medium such as an optical disk (not shown) or the like is
30 read out and stored into the RAM 102 and the CPU 101 executes an arithmetic operation in
accordance with the program, so that a software control unit is constructed. By a combination
of the software control unit constructed as mentioned above and the hardware, the fiinctions of
the rolling control apparatus 100 according to the embodiment are realized.
The foregoing embodiment has been described as an example with respect to the
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case where all of the functions are contained in the rolling control apparatus 100. All of the
functions may be realized in one information processing apparatus in this manner or may be
realized by distributing the functions to a larger number of information processing apparatuses.
It should be fiirther understood by those skilled in the art that although the
foregoing description has been made on embodiments of the invention, the invention is not
limited thereto and various changes and modifications may be made without departing from the
spirit of the invention and the scope of the appended claims.

CLAIMS
1. A rolling control apparatus (100) for controlling a tandem rolling mill which rolls
a strip (1) by a plurality of roll pairs (11, 12, 13), comprising:
a forward slip ratio obtaining unit (31) for obtaining a forward slip ratio in a first
rolling stand (11) corresponding to a condition regarding the rolling of the strip (1) which is
being rolled fi"om information in which the condition regarding the rolling of the strip and the
forward slip ratio have been associated;
a first roll strip speed calculating unit (32) for calculating a conveying speed of
the strip (1) on a delivery side of the first rolling stand (11) on the basis of a roll speed of the first
rolling stand and the obtained forward slip ratio;
a first roll thickness calculating unit (33) for calculating a thickness of the strip on
the delivery side of the first rolling stand on the basis of a thickness of the strip on the entry side
of the first rolling stand, a conveying speed of the strip detected on the entry side of the first
rolling stand, and the calculated conveying speed of the strip on the delivery side of the first
rolling stand;
a forward slip ratio error calculating unit (35) for calculating an error of the
obtained forward slip ratio on the basis of a difference between the thickness of the strip detected
on the delivery side of the first rolling stand and the calculated thickness of the strip on the
delivery side of the first rolling stand;
a second roll thickness calculating unit (34) for calculating a thickness of the strip
on a delivery side of a second rolling stand (12) arranged next to the first rolling stand (11) on
the basis of the thickness of the strip detected on the delivery side of the first rolling stand, the
calculated conveying speed of the strip on the delivery side of the first rolling stand, and a
conveying speed of the strip detected on the delivery side of the second rolling stand; and
a second roll thickness correcting unit (36) for correcting the calculated thickness
of the strip on the delivery side of the second rolling stand (12) on the basis of the calculated
error of the forward slip ratio.
2. The apparatus according to claim 1, further comprising a forward slip ratio
correcting unit (40) for correcting the forward slip ratio associated with the condition regarding
the rolling of the strip (1) which is being rolled on the basis of the calculated error of the forward
slip ratio.
3. The apparatus according to claim 2, wherein the forward slip ratio correcting unit
(40) corrects the forward slip ratio by applying a part of the calculated error of the forward slip
ratio to the forward slip ratio associated with the condition regarding the rolling of the strip (1)
/ > ^ * - t ^ ' ^ ' iM W6925
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which is being rolled. C^'' -'-"' "' A n HfX
4. A rolling control method of controlling a tandem rolling mill which rolls a strip
(1) by a plurality of roll pairs (11, 12, 13), comprising the steps of
obtaining a forward slip ratio in a first rolling stand (11) corresponding to a
condition regarding the rolling of the strip (1) which is being rolled fi"om information in which
the condition regarding the rolling of the strip and the forward slip ratio have been associated;
calculating a conveying speed of the strip on a delivery side of the first rolling
stand on the basis of a roll speed of the first rolling stand and the obtained forward slip ratio;
calculating a thickness of the strip on the delivery side of the first rolling stand on
the basis of a thickness of the strip on the entry side of the first rolling stand, a conveying speed
of the strip detected on the entry side of the first rolling stand, and the calculated conveying
speed of the strip on the delivery side of the first rolling stand;
calculating an error of the obtained forward slip ratio on the basis of a difference
between the thickness of the strip detected on the delivery side of the first rolling stand and the
calculated thickness of the strip on the delivery side of the first rolling stand;
calculating a thickness of the strip (1) on a delivery side of a second rolling stand
(12) arranged next to the first rolling stand (11) on the basis of the thickness of the strip detected
on the delivery side of the first rolling stand, the calculated conveying speed of the strip on the
delivery side of the first rolling stand, and a conveying speed of the strip detected on the delivery
side of the second rolling stand; and
correcting the calculated thickness of the strip on the delivery side of the second
rolling stand (12) on the basis of the calculated error of the forward slip ratio.
5. A rolling control program for controlling a tandem rolling mill which rolls a strip
(1) by a plurality of roll pairs (11, 12, 13), wherein the program allows an information processing
apparatus to execute the steps of
obtaining a forward slip ratio in a first rolling stand (11) corresponding to a
condition regarding the rolling of the strip (1) which is being rolled fi-om information in which
the condition regarding the rolling of the strip and the forward slip ratio have been associated;
calculating a conveying speed of the strip on a delivery side of the first rolling
stand on the basis of a roll speed of the first rolling stand and the obtained forward slip ratio;
calculating a thickness of the strip on the delivery side of the first rolling stand on
the basis of a thickness of the strip on the entry side of the first rolling stand, a conveying speed
of the strip detected on the entry side of the first rolling stand, and the calculated conveying
speed of the strip on the delivery side of the first rolling stand;
, !«..- ,^. - • W6925
- 1 5 - C . - -. ""h UC:^
calculating an error of the obtained forward slip ratio on the basis of a difference
between the thickness of the strip detected on the delivery side of the first rolling stand and the
calculated thickness of the strip on the delivery side of the first rolling stand;
calculating a thickness of the strip (1) on a delivery side of a second rolling stand
(12) arranged next to the first rolling stand (11) on the basis of the thickness of the strip detected
on the delivery side of the first rolling stand, the calculated conveying speed of the strip on the
delivery side of the first rolling stand, and a conveying speed of the strip detected on the delivery
side of the second rolling stand; and
correcting the calculated thickness of the strip on the delivery side of the second
rolling stand (12) on the basis of the calculated error of the forward slip ratio.
6. A rolling control apparatus, substantially as herein described with reference to
accompanying drawings and examples.
7. A rolling control method, substantially as herein described with reference to
accompanying drawings and examples.
8. A rolling control program, substantially as herein described with reference to
accompanying drawings and examples.