JPH09323111A - Material tracking device and tracking method in rolling mill - Google Patents

Abstract

(57) Abstract: A tracking device and a tracking method capable of accurately tracking a welded portion of a rolled material. SOLUTION: A signal monitoring device 11 for detecting arrival of a welding point 3 of a steel plate by a pressure gauge 2a, 2b installed on a NOi-1 stand 1a, a NOi stand 1b and sending a welding point passage signal, and a welding point passage signal. When the passage of the welding point is recognized by the tracking computing device 10 that detects the plate speed by the plate speed meter 6b and corrects it by the tracking correction coefficient.
And a learning correction device 8 for calculating an error ratio from the plate speed value obtained by the plate speed meter and the set distance data between rolling mills and the like, and determining a correction coefficient for correcting the next plate speed value. There is.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rolling size change point or a material welded portion tracking in a rolling mill when changing a running size or welding different steel types in a tandem rolling mill.

[0002]

2. Description of the Related Art Recently, quality, yield, and
For the purpose of improving the production unit and productivity, the trailing edge of the preceding material and the leading edge of the trailing material are joined on the inlet side of the rolling mill, and shear splitting is again performed on the outlet side so that multiple materials can be rolled. Continuous rolling is being continued.

In such continuous rolling, the position of the welding portion in the rolling mill is accurately tracked every moment, and shear splitting at the rolling mill exit side is performed at an optimal timing or in advance. When rolling a different thickness steel sheet having different sheet thicknesses between the material and the succeeding material, it is important to control the roll interval at the joining point to change the sheet thickness.

As a technique relating to such tracking, the method disclosed in Japanese Patent Publication No. 3-73366 is known.

In this technique, when the weld to be tracked reaches the former rolling mill, signal measurement from the pulse transmitter installed in the latter rolling mill is started, and the number of measured pulses is the distance L between the stands. , The roll diameter R, the number N of pulse oscillations per roll revolution, and the count value based on the backward movement ratio b reach the value K calculated in advance by the following equation, K = LN / πR (1-b), the weld zone From the time when the weld reaches the i-th rolling mill,
Welding part tracking up to +1 rolling mill is performed. In this case, the tracking is not based on the progress of the trailing material.
By tracking the inside of the mill by the amount of advance of the preceding material using the backward movement rate, the moving speed of the welded portion can be estimated more accurately to achieve highly accurate tracking.

[0006]

However, in the above-mentioned conventional example, the backward movement rate b is used in place of the forward movement rate having a large error in the estimation formula to improve the tracking accuracy. It is given by b = h / H · (1 + ff) from f, rolling mill entrance side plate thickness H, and exit side plate thickness h. In tandem rolling, the plate thickness other than between rolling mills that can be measured with a plate thickness gauge is estimated and calculated. However, it is customary that the plate thickness in the case of the estimation calculation includes an error of 4 to 5% at maximum because dynamic disturbance such as wear of roll during rolling and temperature expansion is also added. . For this reason, when h and H include a relative error of 5% in the calculation formula for the backward movement rate b, the backward movement rate b also includes the same amount of relative error, and when this is used for tracking, There is a problem that the accuracy is significantly reduced.

Further, an error between rolling mills in tandem occurs at the time of tracking, but since the tracking start time point between the subsequent rolling mills is selected based on the tracking result of the preceding rolling mill, all the errors are accumulated from the preceding stage. There is a problem that the tracking accuracy decreases as it goes to the later stage.

Therefore, it is an object of the present invention as set forth in claims 1 and 3 and 4 to provide a material tracking device in a rolling mill capable of more accurately tracking a welded portion of a material to be rolled in a tandem rolling mill. It is in.

Further, an object of the invention described in claims 2 and 5 is to provide a material tracking method in a tandem rolling mill capable of tracking a welded portion of a material to be rolled with less error and more accurately. It is in.

[0010]

In order to achieve the above object, the invention according to claim 1 is characterized in that a welded portion of a steel sheet is formed by rolling a steel sheet obtained by joining a preceding steel sheet and a following steel sheet with a tandem rolling mill. In the tracking device, a signal monitoring device that detects the arrival of the welded portion of the steel sheet from the measurement value by the detection device of the pressure gauge installed in each rolling mill and outputs a welded portion passing signal, and welding by the welded portion passing signal The sheet speed is detected by the sheet speed meter installed on the exit side of the rolling mill that recognizes the passage of
A tracking calculation device that corrects this detected value with a predetermined correction coefficient, and an error ratio is calculated by the ratio of the integrated value of the plate speed detected by the plate speed meter and the preset distance data between rolling mills. Then, a learning correction device for determining the correction coefficient for correcting the plate speed measurement value of the next joined steel plate is provided.

According to this structure, when the signal monitoring device detects the joining point due to the load change of the pressure gauge, the tracking calculation device measures the plate speed and corrects it by the correction coefficient learned and calculated by the learning correction device. Tracking, so
The error is reduced by highly accurate correction using the correction coefficient,
More accurate tracking can be performed.

Further, the invention according to claim 2 is installed in each rolling mill in a method of tracking a welded portion of the steel sheet during rolling of the steel sheet obtained by joining the preceding steel sheet and the following steel sheet with a tandem rolling mill. The size change point immediately below each rolling mill or the actual passing time t0 of the welded portion is obtained from the change in the measured value by the pressure gauge detection device, and the actual running time t0 passing through the preceding rolling mill is used as the starting point for each preset tracking calculation cycle. The size change point on the outlet side of the rolling mill or the weld position X to V
(T) dt is obtained by integrating from time t0 to t, the size change point or the weld arrival time t1 is detected by the pressure gauge provided in the subsequent rolling mill, and the position X obtained by the above calculation and the above The empirical error ratio ds obtained by obtaining and storing the error ratio d as L / X from the mechanical rolling mill distance L which is the detection end position detected at time t1 and performing learning or / and statistical processing It is characterized in that the size change point of the next material or the welded portion position Xn is tracked by being corrected by being multiplied by the subsequent X value.

According to this structure, the estimated position X reaching the next rolling mill at each preset calculation cycle is set to the steel plate speed V of the steel sheet speed V with the joining point passage time t0 immediately below the rolling mill obtained from the pressure gauge as the starting point. The position data X is corrected by the empirical error ratio ds obtained by predicting and estimating by the function integral calculation, the error ratio d = L / X with the actual mechanical rolling mill distance L, and performing the learning statistical processing. It is possible to perform the tracking based on the accurate distance between the rolling mills by correcting with the highly accurate empirical error ratio ds.

According to the third aspect of the invention, the detection device for detecting the passage of the joining point includes a strip width gauge and / or a strip thickness gauge installed between rolling mills.

According to this structure, not only the pressure gauge immediately below the rolling mill but also the measured value of the strip width gauge between the rolling mills can be used as the position detection signal of the joining point, so that many necessary for accurate tracking can be obtained. It is possible to obtain the position detection data of the junction point. In addition to the pressure gauge and the width gauge, when steel sheets with different thicknesses are joined, the detection data from the thickness gauge can also be used as a position detection signal at the joining point, which is necessary for accurate tracking. A lot of junction detection data can be obtained.

According to a fourth aspect of the present invention, the learning correction device stores an inter-device distance storage device that stores mechanical distance data, an error calculator that calculates an error ratio, and a past error history. And an average value calculator that determines a correction coefficient by averaging the error ratio calculated by the error calculator and the past error history.

According to this structure, the error calculator calculates the error ratio from the predicted estimated value calculated from the data of the detection device and the mechanical distance data stored in the inter-device distance storage device,
Since the average value calculator performs the averaging process based on the error ratio and the past error history of the error history storage device to determine the correction coefficient, a highly accurate correction coefficient used for tracking correction can be obtained.

Further, in the invention according to claim 5, the empirical error ratio ds is a normal distribution created based on an angular deviation α / α ′ obtained from a characteristic graph of a distance between mechanical rolling mills and an elapsed time. The feature is that it is obtained from the characteristics.

According to this structure, the normal deviation curve is created by obtaining the angle deviation α / α ′ from the angle α ′ formed by the distance between the mechanical rolling mills and the arrival position estimation time and the angle α formed by the actual arrival time. Since the degree of deviation from the average value is used as the empirical error ratio ds, it is possible to obtain a ds value that enables highly accurate correction.

[0020]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram of a material tracking device in a rolling mill according to an embodiment of the present invention. In FIG. 1, reference numeral 1 is a tandem rolling mill that performs continuous rolling, and includes two rolling mills 1a (NOi-1 stand) and 1b.
(NOi stand) is shown (usually, there are often seven units). 2a and 2b are NOi-1 stand 1a and NOi
A load cell type pressure gauge for load detection installed on the backup roll of the stand 1b, and 3 is a point where the left and right steel strips are welded at the joining point (welded portion) of the steel sheets, which progresses to the right in the figure. . Reference numeral 4 is a strip width gauge installed between rolling mills, and 5 is a strip thickness gauge (X-ray strip thickness gauge or the like).

Reference numerals 6a, 6b and 6c are plate speed gauges for detecting the output plate speed of each stand. Reference numerals 7a, 7b and 7c are correction coefficient circuits for setting a correction coefficient F for correcting the measured value of each plate speed meter, and 8 is a learning correction device for learning and calculating the correction coefficient F or the empirical error ratio ds. Is. 9a, 9
Reference numerals b and 9c denote integrating circuits (plate speed integrating devices) that integrate the measurement outputs V of the plate speed meters 6a, 6b, and 6c and output welding position information X. The outputs of the integrating circuits are other than those of the rolling mill 1. Is also supplied to the equipment as a welding position information through a data highway (a network such as a process computer and a vidicon by an optical LAN in the facility) 12.

Reference numeral 10 is a tracking arithmetic unit for performing various arithmetic operations for tracking execution according to the arrival timing of the welded portion 3, and 11 is a signal monitoring unit for the pressure gauges 2a, 2b.
Alternatively, it is a signal monitoring device that detects arrival of the welded portion 3 based on measurement inputs from the strip width gauge 4 and the strip thickness gauge 5 and sends a welding portion passage signal to the tracking calculation device 10. A pressure gauge, a plate width gauge, and a plate gauge are passed to the signal monitoring device 11 to detect the passage of the welding portion, and the pressure gauge, the width gauge, and the thickness gauge detect the welding portion. Make up.

FIG. 2 is a circuit block diagram of the signal monitoring apparatus 11 shown in FIG. In FIG. 2, 20 is an input signal from each detection device such as a pressure gauge, 21 is a differentiator of the input signal, 2
Reference numeral 2 is a comparator that compares the magnitude of the load change from the pressure gauge 2 detected by the differentiator 21 with a set threshold value 23 to determine the arrival of the welded portion 3.

FIG. 3 is a block diagram of the learning correction device shown in FIG. In FIG. 3, A is an integrating circuit 9a, 9b, 9
The tracking calculation position information X and B input from c are actual mechanical distance data such as the distance L between the rolling mill and the rolling mill, the distance between the rolling mill and the strip width gauge, or the distance between the rolling mill and the strip thickness gauge. An inter-device distance storage device storing each distance data of C, an error calculator for calculating an error ratio d = L / X from the input position information X and the distance information stored in the storage device B,
E is an error history storage device that stores past error history data for learning, and D is an average value calculator that determines the correction coefficient F by averaging the error ratio d obtained by the error calculator C and the error history data. Is.

Next, the operation will be described. Rolling mill 1a
When the welded portion 3 reaches directly below, the output load value of the pressure gauge 2a changes. Signal 2 of load change detected by pressure gauge 2a
When 0 is input to the signal monitoring device 11 having the configuration shown in FIG.
The differentiator 21 extracts the magnitude of the signal and the comparator 22
If the input is larger than the threshold value 23, it is determined that the welding portion has arrived, and a welding portion passage signal is sent to the tracking device 10.

The passage of the weld 3 is detected by the pressure gauge 2a,
Not only 2b but also the detected values of the welded portion 3 by the plate width gauge 4 and the plate thickness gauge 5 are individually processed by the signal monitoring device 11 in the same manner as in the case of the pressure gauge, and the width gauge 4 and the plate gauge The position information of the welded portion 3 passing through each of the thickness gauges 5 is also taken in as tracking information to improve the accuracy of the detection information.

When the tracking calculator 10 receives the welding portion passage signal of the pressure gauge 2a provided on the NOi-1 stand 1a and recognizes the passage of the welding portion 3, the plate provided on the outgoing side of the NOi-1 stand 1a. The speed plate 6b detects the outgoing plate speed V and operates the integrating circuit 9b. The integral calculation in the integrating circuit 9b is performed by the plate speed V detected by the plate speed meter 6b as in the following equation.
Therefore, the estimated tracking position X at which the welded portion arrives after t hours is obtained by integration from the welded portion arrival time t0 to the estimated time t at which the welded portion 3 arrives at the next NOi stand 1b rolling mill based on the tracking calculation cycle. This is a prediction calculation.

[0028]

[Equation 1] The tracking calculation position X obtained by the equation (1) is also supplied from the data highway 12 to other equipment as tracking information starting from time t0.

Subsequently, the welded portion 3 is the next NOi stand 1
When the time t1 is reached at b, the signal monitoring device 11 judges from the detection value from the pressure gauge 2b and sends out the welding portion passing signal, the tracking device 10 uses the plate speed meter 6c to measure the exit side plate speed V1 of the NOi stand 1b. Detecting and operating the integrating circuit 9c, from the time t1 regarding V1 by the above equation (1),
The next tracking position X1 is obtained by performing integration for the estimated time t2 at which the weld reaches the next rolling mill.

At the same time, the tracking arithmetic unit 10 passes the output tracking position X of the integrating circuit 9b of the front rolling mill 1a to the learning correction unit 8. In the learning correction device 8, the input A of the tracking position X as shown in FIG. 3 and the NOi-1 stand 1a-N stored in the inter-device distance storage device B are stored.
Distance L between Oi stands 1b, NOi-1 stand 19
Between the plate width meter 4 and the width meter ₁ , NOi-1 stand 1a
The corresponding distance data (for example, the distance L between the NOi-1 stand 1a and the NOi stand 1b) is read according to the distance L ₂ between the plate thickness gauge 5 and the error ratio d = L / Calculate X.

Further, in the average value calculator D, using the previously obtained error ratio d and the past error history stored in the error history storage device E in advance, the averaging process described below is performed and the next time The correction coefficient F to be multiplied by the plate speedometer output of is determined.

FIG. 4 is an explanatory diagram of the error ratio calculation by the error calculator shown in FIG. How to obtain the error ratio d will be described in detail with reference to FIG. In FIG. 4, the vertical axis indicates the distance between the mechanical devices read from the device distance storage device B, and here, as an example, NOi-1 stand 1a-NOi stand 1b.
Distance: L The horizontal axis represents the tracking time, and the estimated time t with respect to the tracking distance X starts from the time point t0 when the welded portion 3 reaches the NOi-1 stand 1a.
And the actual time t1 at which the welded portion 3 actually reaches the next NOi stand 1b.

The intersection Q ₁ of the time t and the distance L on the graph of the figure
And a straight line a connecting t0 and each of the intersection points Q ₂ of t1 and L,
b, and the angle Q ₂ -t0-t1 is α = L / (t1-t
0) and the angle Q ₁ -t0-t is α '= L / (t-t0), the error ratio d = L / X on the distance is equivalent to the error ratio in terms of velocity and the angular deviation [ α ′ / α].

FIG. 5 is an explanatory diagram of the averaging process in the average value calculator shown in FIG. The calculation of the correction coefficient will be described in detail with reference to FIG. Since the error history storage device E stores deviations [α '/ α] corresponding to past measurement frequencies, these are statistically processed, the sum of squares of each deviation data is divided by the frequency, and the square root is calculated. The standard deviation “σ” is calculated and plotted, and the deviation α ′ / α = 0 as shown in FIG.
Centered around the average value of + 1.96 · σ to −1.
Create a normal distribution in the range of 96 · σ.

In actual control, when the weld reaches the α '
After obtaining / α, the corresponding value F on the vertical axis where the maximum value at the center of the curve is the average value = 1 is found on the normal distribution curve of FIG. 5, and the correction coefficient F of ± is determined. The content of the correction coefficient 7b is rewritten so that the next plate speed is Vs.
By correcting as = VF, the measurement error is reduced.

Further, the correction coefficient of the tracking position, which is equivalent to the correction rate of the plate speed V by the correction coefficient F, is expressed by the formula (1) X.
Which corresponds to the empirical error ratio ds for correcting the error, which makes it possible to control the tracking position of the welded portion 3.

As described above, the series of processes other than the pressure gauge 2 such as the thickness gauge 5 and the width gauge 4 existing at the time when the welded portion 3 reaches each rolling mill and between the rolling mills are performed. Also from the signal of the detection system, each time the welding portion 3 is recognized, the tracking accuracy is increased and tracking is executed until reaching the final rolling mill.

Thus, according to this embodiment, as shown in FIG.
As shown in the comparison diagram of the tracking result of No. 1, in the case of the conventional example, the correction is not suitable as indicated by the long dotted line, so
As the process proceeds from the stand 1a to the next NOi stand 1b, errors are accumulated and the tracking position is largely deviated. In comparison, in the case of the present embodiment, the position is shorter than the solid line showing the actual position transition of the welded portion. As shown by the dotted line,
Since the tracking error generated in the first NOi-1 stand 1a is also reduced by the correction, the tracking error in the next NOi stand 1b becomes small and the optimum tracking approaching the solid line is performed.

Further, as a result of actually performing the welding part tracking with the actual equipment having the configuration shown in FIG. 1, the tension fluctuation at the time of changing the running plate thickness is reduced to about half after the performance learning of several tens of wires. And good continuous rolling could be performed.

Further, by improving the tracking accuracy,
Coil shearing after finish rolling, the length between the joint and the cutting point in the winding process, that is, the other coil that remains with the joint needs to be sheared longer in consideration of the amount of variation as in the past. It has become possible to significantly improve the yield.

[0041]

As described above, according to the present invention,
In continuous rolling with a tandem rolling mill, the actual time t0 of passage of the steel strip weld is detected by a pressure gauge immediately below each rolling mill, a strip width gauge between the rolling mills, and a thickness gauge, etc. Until the estimated time for the weld to reach the next rolling mill,
The tracking welding portion position X is obtained by integrating V (t) dt with respect to the detected plate speed V, and the time t1 at which the welding portion actually arrives at the subsequent rolling mill is detected, and the learning correction device mechanically rolls the rolling mill. The tracking estimated position error with the inter-distance L is calculated to obtain and store the error ratio d = L / X, and learning or / and statistical processing is performed to calculate the plate speed correction value F or the empirical error ratio ds. Since the tracking calculation device corrects the tracking value, it is possible to accurately track the running size change point of the rolled material or the welded part in the tandem rolling mill with significantly reduced errors. .

[Brief description of drawings]

FIG. 1 is a block diagram of a material tracking device in a rolling mill according to an embodiment of the present invention.

FIG. 2 is a circuit block diagram of the signal monitoring device shown in FIG.

FIG. 3 is a block diagram of the learning correction device shown in FIG.

FIG. 4 is an explanatory diagram of an error ratio calculation by the error calculator shown in FIG.

5 is an explanatory diagram of averaging processing in the average value calculator shown in FIG. 3. FIG.

FIG. 6 is a comparison diagram of a welding portion tracking result by the tracking device shown in FIG. 1.

[Explanation of symbols]

 1 Tandem rolling mill 2 Pressure gauge 3 Welding part 4 Strip width gauge 5 Strip thickness gauge 6 Strip speed gauge 7 Correction coefficient circuit 8 Learning correction device 9 Strip speed integrating circuit 10 Tracking calculation device 11 Signal monitoring device 12 Data highway

Claims (5)

[Claims] 1. A device for tracking a welded part of a steel plate during rolling of a steel plate obtained by joining a preceding steel plate and a following steel plate by a tandem rolling mill, based on a measurement value by a detection device of a pressure gauge installed in each rolling mill. A signal monitoring device that detects arrival of the welded portion of the steel sheet and outputs a welded portion passage signal, and a plate speed by a sheet speed gauge provided on the exit side of the rolling mill that recognizes passage of the welded portion by the weld portion passage signal. And a tracking calculation device that corrects the detected value with a predetermined correction coefficient, and an error due to the ratio of the integrated value of the plate speed detected by the plate speed meter and the preset distance data between rolling mills. A material tracking device in a rolling mill, comprising: a learning correction device that calculates a ratio and determines the correction coefficient for correcting the plate speed measurement value of the next bonded steel plate. 2. A method of tracking a welded part of a steel sheet while a steel sheet obtained by joining a preceding steel sheet and a following steel sheet is being rolled by a tandem rolling mill, wherein a value measured by a detector of a pressure gauge installed in each rolling mill is used. The size change point immediately below each rolling mill or the actual passing time t0 of the welded portion is obtained from the change, and the actual size t0 of passing through the preceding rolling mill is used as a starting point to change the size of the rolling mill exit side at each preset tracking calculation cycle. The point or weld position X is obtained by integrating V (t) dt from time t0 to t, and the size change point or weld arrival time t1 is detected by the pressure gauge provided in the subsequent rolling mill,
An error ratio d is obtained and stored as L / X from the position X obtained by the calculation and the inter-mechanical rolling mill distance L which is the detection end position detected at the time t1, and the learning is performed and / or statistical processing is performed. A material tracking method in a rolling mill, characterized in that the size change point of the next material or the welding position Xn is tracked by multiplying the empirical error ratio ds obtained by the following X value to correct. 3. The rolling mill according to claim 1, wherein the detection device for detecting the size change point or the passage of the welded portion includes a strip width gauge and / or a strip thickness gauge installed between rolling mills. Material tracking device. 4. The learning correction device includes an inter-device distance storage device that stores mechanical distance data, an error calculator that calculates an error ratio, an error history storage device that stores a past error history, and The material tracking device in a rolling mill according to claim 1, further comprising an average value calculator that determines a correction coefficient by averaging an error ratio calculated by an error calculator and the past error history. 5. The empirical error ratio ds is an angular deviation α obtained from a characteristic graph of distance between mechanical rolling mills and elapsed time.
The material tracking method in a rolling mill according to claim 2, wherein the material distribution is obtained from a normal distribution characteristic created based on / α '.