JPS60115327A - Camber measuring method of steel plate - Google Patents

Abstract

PURPOSE:To evade an up-and-down motion and an inclination from a standard pass line of a steel plate, and a measuring error in case an angle in the advancing direction is varied, by forming plural groups by position detectors at each edge, and correcting a position, in a titled method for detecting both edges of the steel plate at three or more points in the longitudinal direction of the steel plate. CONSTITUTION:At three measuring points (a)-(c) which have left a prescribed interval L in the longitudinal direction of a steel plate 1 both edge positions of the plate 1 are detected by a command from an arithmetic part whenever the steel plate 1 moves by the length L. This detection is executed by position detectors 201-212 which have left a prescribed distance in the upper part of the plate 1, totaling to 12 sets consisting of two sets each to each edge. Their signals are sent to position detecting parts 301-312, and each position detecting result is stored successively in position storage parts 401- 412 at every measurement. From said measuring result, an arithmetic for correcting a position detecting error in case when an up-and-down motion and an inclination from a standard pass line of the plate 1 have been generated is executed by arthmetic parts 51-56, and a width center position at the points (a)-(c) is derived by arithmetic parts 61-63. Subsequently, the superposed arithmetic is executed by an arithmetic part 7, and the continuation is executed in the longitudinal direction.

Description

[Detailed description of the invention] Industrial applications The present invention relates to a method for measuring camber of a steel plate.

Generally, when a steel plate is rolled in a steel plate mill or a hot rolling mill, lateral bending δ of the rolled material 1 as shown in FIG. 1, called camber, may occur due to various causes. When such camber occurs, the yield when taking products of a specified size in the refining process of thick steel plates decreases, and in hot rolling mills, it may interfere with the threading in the finishing mill, and it may cause problems in coils. This causes poor winding appearance after winding and a decrease in yield during width trimming in the next process. Therefore, it is extremely important to accurately measure the amount of camber during rolling and use the results to quickly control the camber correction.

Problems with the Prior Art Methods for measuring the camber of steel plates are disclosed, for example, in JP-A-49-89172, JP-A-49-97647, and JP-A-50-104050. As shown in Fig. 2, this method involves installing three etch distance meters 21, 22, and 23 along a reference line A that is approximately parallel to the direction in which the steel plate 1 travels, and measuring the distance from the reference line A to the nip on one side of the steel plate 1. The amount of camber is calculated by measuring the distances da%db and dc. However, this method cannot accurately measure the camber when the width of the steel plate 1 changes in the longitudinal direction as shown in the figure.

In other words, the true camber obtained by connecting the widthwise center positions Ca5Cb1CC of the longitudinal positions a, b, and c of the steel plate 1 with a straight line is zero, but in reality, the camber is measured as if it were δ. There is a problem with this.

On the other hand, as a camber measurement method that solves this problem, there is a method disclosed in, for example, Japanese Patent Laid-Open No. 52-44656. This method is 3 in the longitudinal direction of the steel plate.
The camber is measured by detecting both etched positions of the steel plate at more than one location using a solid-state imaging device, and determining the center position in the width direction of each point in the longitudinal direction based on the detection results. According to this method, it is possible to measure the camber even when there is a width change in the steel plate as described above. However, if the steel plate moves up and down from the reference pass line as shown in Figure 3(a), or if it is tilted as shown in Figure 3(b), the steel plate etch as seen from the position detector 2 The viewing angle changes by θ8 and θ2, respectively, and as a result, the detected etch position has an error of 13.12 from the true edge position, resulting in an error in the camber amount, which reduces measurement accuracy. becomes worse. Furthermore, the total camber amount is the camber amount in a section of length 2L between a and c in FIG. 1, and it is not possible to measure the camber amount over an arbitrary section.

In addition, the method disclosed in Japanese Patent Application Laid-open No. 58-68605 captures images of the surface of a steel plate every predetermined length using a two-dimensional imaging device and synthesizes them in the longitudinal direction to determine the amount of camber. be. With this method, the amount of camber can be adjusted over an arbitrary length section by correcting errors caused by positional fluctuations in the width direction of the steel plate (hereinafter referred to as tracking), but as mentioned above, vertical movement or inclination of the steel plate may occur. There is a problem that a measurement error occurs when an angular variation in the traveling direction occurs.

Purpose of the Invention The present invention is aimed at solving each of the above-mentioned problems.It is an object of the present invention to eliminate measurement errors even when vertical movement or inclination of the steel plate from the standard pass line or angular change in the direction of movement occurs. The object of the present invention is to provide a method that can accurately adjust the amount of camber over an arbitrary section in the longitudinal direction of a steel plate without causing any problems.

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a method for measuring camber by detecting both edges of a steel plate at at least three measurement points in the longitudinal direction of a steel plate. Two or more pairs of position detectors are installed on the edge at a predetermined distance above or below the steel plate, and the position detectors detect both etch positions of the steel plate at each measurement point at time intervals that take the advancing speed of the steel plate into consideration. Then, position correction 4- is performed based on the two or more detection results obtained for each etch, and the width center position of the steel plate at each measurement point is determined from the position correction results, and the previous position is calculated based on the movement of the steel plate. The -1 part of the width center position at each measurement point is overlapped with the obtained width center position to make the width center position continuous in the longitudinal direction, and the continuous width center positions are connected with a straight line to obtain an arbitrary measurement section. This is a method for measuring camber of a steel plate, which is characterized by measuring the amount of camber at .

Effect of the Invention The method of the present invention will be explained in detail below with reference to the accompanying drawings. FIG. 4 is a schematic diagram showing an example of implementing the method of the present invention, in which 1 is a steel plate, 201 to 212 are position detectors for detecting the edge position of the steel plate, and points a, 1), and c are These are measurement points in the longitudinal direction of the steel plate 1. FIG. 5 is a diagram showing an example of the configuration of a calculation section that calculates the amount of camber from the position detection results by the position detectors 201 to 212. In the figure, 301 to 312 are position detection units, 401 to 41
2 is a position storage unit, 51 to 56 are position correction calculation units, 61.
Reference numerals 62 and 63 designate a central position calculation section, 7 a camber amount calculation section, and 8 a measurement and timing calculation section.

As shown in FIG. 4, each time the steel plate 1 moves by a predetermined length in the longitudinal direction at three measurement points aSb1c spaced at predetermined intervals in the longitudinal direction of the steel plate 1, the measurement timing calculation unit 8 A total of 12 position detectors 201 - 2 position detectors for each etch position detect both etch positions of the steel plate 1 according to a command.
212, and sends the detection signal to position detection units 301 to 312 shown in FIG. In addition, in this explanation, the cylinder road of explanation,
Although the number of measurement points in the longitudinal direction was three, four or more may be used.

Although three or more position detectors may be used for one edge, the required purpose can be achieved with two. Next, the position detection results by the position detection units 301 to 312 are sequentially stored in the position storage units 401 to 412 for each measurement. Based on the above measurement results, calculations for correcting position detection errors when vertical movement or inclination of the steel plate 1 from the reference path line occurs are performed by the method described below.

FIG. 6 is a diagram showing the principle of correcting position detection errors caused by vertical movement and inclination of the steel plate 1 from the reference path line in the method of the present invention. In the figure, 1 is a steel plate, 20
1 to 204 are position detectors, and by detecting one etch using two position detectors, the position can be detected, for example, when the left etch position moves upward by Y from the reference path line. The position detector 201 detects X2 from the reference position 1, and the position detector 202
Then, it is detected as xl from the reference position 1. In order to determine the true left edge position X in such a state, the position correction calculation unit 51756 shown in FIG. Perform correction calculations. Note that the symbols in FIG. 6 are the values shown below.

U: Distance between position detectors 201 and 202 and distance between position detectors 203 and 204 V Distance between position detector 201 and reference position 2 and distance between position detector 204 W: Position detector 202
and 203 distance H: Height from the reference pass line to the position detectors 201 to 204 Y Violet: Height of the left edge of the steel plate l from the reference pass line Y2: Height of the right edge of the steel plate l from the reference pass line X: True left side etch position X from reference position 1: Left side etch position x2 from reference position l, detected by position detector 202 = position detection, detected by output device 201, from reference position 1 Left edge position Z: true right edge position 2 from reference position 2;: right edge position Z from reference position 2 detected by position detector 203! : Right side etch position fil from the reference position 2 detected by the position detector 204, from equation (2), HX+(X, -U-V)Y, =HX,... Song (31HX
+ (x*-V)Y, = HXi −・Song・・・・・・
+41 From equations (3) and (4), the true left etch position X is determined in this way.

Similarly, for the right side etch position Z, Z - Z,
+U Thus, from equations (6) and (8) above, the true position of both edges is X.

2 can be accurately set without causing any error even if the steel plate l moves vertically or tilts from the reference path line. Such position correction calculations are performed for each measurement point a1b1C in FIG. 4 to accurately set both etch positions on the steel plate 1.

The central position calculation section 61, 62, and 63 shown in (9) below
Perform calculations on expressions.

C= Next, the center position in the width direction for each measurement obtained in this way is sent to the camber amount calculating section 7 shown in Fig. 5, and the "superimposition calculation" is performed in the method described below to continuously measure the width in the longitudinal direction. . The purpose of performing this "superposition calculation" is to correct the shift in the width center position of the steel plate for each measurement when the steel plate 1 causes tracking or changes in angle with respect to the direction of movement during measurement. It is.

For example, as shown in FIG. 7(a), the width center positions Cb(i) and Cc(i) of point D and six points at the time of the (i)th measurement
are point a and point b at the (i+1)th measurement, respectively.
Although the points are the same as the width center positions ca (i+1) and Cb (i+1), when tracking of the steel plate 1 occurs, a deviation of δT occurs in the width direction. By removing this deviation δT in the width direction, Cc(i
-H) to Ca(i), Cb(i), Cc(i) After CD, the following (lO)
Using the formula, Cc(i+1) is set as Cc(i+1).

(, c (i+1)=L-tan(θ,=02+θm)
+ CC(i) ・---flo)L: Each measurement point a1
Distance between b and C By sequentially and repeatedly performing the "superimposition calculation" using the above formula (lO), it is possible to find a continuous width center position over the entire length of the steel plate 1.

As shown in FIG. 8, the width center position made continuous in the longitudinal direction is connected with a straight line L1, Ca[1) and CC(
The maximum distance δ to the straight line L2 connecting It is quantity. Therefore, by changing the measurement target section, the amount of camber of the steel plate 1 in any section can be determined.

Note that the position detectors 201 to 212 used in the method of the present invention are, for example, solid-state imaging devices that are a combination of a camera, a CCD, an MO8 type photodiode, etc., but other detection means may also be used. In addition, the camera used has a depth of focus that takes into account the vertical movement of the steel plate. Furthermore, the field of view of each position detector can be narrowed by making each pair of position detectors that detect both etch positions movable in the width direction while maintaining a predetermined interval according to the width of the steel plate. Therefore, the resolution ability of position detection can be improved, and the accuracy of measuring the amount of camber obtained as a result can be improved.

EXAMPLE As an example of the method for measuring camber of a steel plate according to the present invention, an example will be described in which the amount of camber of a hot rolled steel plate was measured using an apparatus and a calculation section having the configuration shown in FIGS. 4 and 5.

In this specific example, as shown in Fig. 4, there are three measurement points in the longitudinal direction of the steel plate, the distance between each measurement point is 1.5 m, and both etch positions of the steel plate 1 at each measurement point are A total of 12 position detectors 201 to 212 were provided above the steel plate 1, with two position detectors being used perpendicularly to the longitudinal direction for each edge for detection. Note that the position detectors 201 to 212 use solid-state imaging devices that combine a camera and a COD, and each position detector has a field of view of approximately 1.
000mm (actual field of view 800mm), CCC uses a 2048-bit element, and the position detection resolution in the width direction is approximately 0.5t.
III/Pinto and one. In addition, the installation conditions for the position detector are as shown in Fig. 6, U=200 order, V=80
0 order, W=11ooffff, H=300om, the width of the steel plate to be measured was 800 to 1800 mm, and the allowable tracking of the steel plate was between ±150 mm. A device having such a configuration was installed on the exit side of a hot rolling finishing stand, and camber was measured using a calculation device having the configuration shown in FIG.

In the conventional method as a comparative example for the method of the present invention, the number of longitudinal measurement points is three, the distance between each measurement point is 1.5 m, and the number of position detectors for each edge is one for each edge. The test was carried out using the same six machines as the method of the present invention, and without performing position correction for vertical movement or inclination of the steel plate.

Effect of the invention By using the above two methods, raw material 3゜4 fins x width 1000 mm, raw material 2゜6 scrap leather x width 1250 mg, thickness 3.0 mm x width 1700 mm
Table 1 shows a comparison between the results of measuring the amount of camber in a 6 m long portion from the top of the rolling top of my hot-rolled steel sheet and the amount of camber actually measured off-line.

Note that Y in Table 1 is a value obtained by visually measuring the vertical movement of the steel plate under measurement from the reference pass line. In the method of the present invention, position correction calculations are performed for one edge using two position detectors, and continuity is achieved by "overlapping" to eliminate tracking of the steel plate and changes in the direction of travel angle. Since the camber of the steel plate is adjusted, as shown in Table 1, the camber measurement error is significantly improved compared to the conventional method.

As explained above, the method of the present invention is an excellent method for measuring camber of a steel plate, which can accurately measure the camber group of a steel plate.

Table 1

[Brief explanation of the drawing]

Figure 1 is a diagram showing the principle of camber measurement, Figure 2 is a diagram showing an example of camber measurement using the conventional method, Figure 3 is a diagram showing position detection errors due to vertical movement and inclination of the steel plate, and Figure 4 is a diagram showing the position detection error due to vertical movement and inclination of the steel plate. The figure shows one example of the installation situation of a position detector for carrying out the method of the present invention.
A schematic diagram showing an example, Fig. 5 shows the camber from the position detection results.
FIG. 6 is a diagram showing the principle of position correction in the method of the present invention; FIG. 7 is a diagram showing the superposition of width center positions according to the method of the present invention; FIG. 2 is a diagram showing a state in which the amount of camber is increased from the continuous width center position. 1... Steel plate, 201.202.203.204.20
5.206.207.208゜209, 210.211
．． 212...Position detector, 301.302.303°304, 305.306.307.308.309.3
10.311.312...Position detection unit, 401.40
2.403.404.4'05.406.407.40
8.409°410, 411.412...Position storage unit, 51.52.53.54.55.56...Position correction calculation unit, 61.62.63...Center position calculation unit, 7.
... Camber amount calculation section, 8... Measurement timing calculation section. Applicant: Sumitomo Metal Industries, Ltd.

Claims (1)

[Claims] In a method of measuring camber by detecting both etches of a steel plate at at least three measurement points in the longitudinal direction of the steel plate to be measured, two or more sets of position detectors are installed at each etch of each measurement point. The position detector is installed at a predetermined distance above or below the steel plate, and the position detector detects both etch positions of the steel plate at each measurement point at time intervals that take the advancing speed of the steel plate into consideration. The position is corrected based on the detection results of more than 100 pieces, the width center position of the steel plate at each measurement point is determined from the position correction result, and the width center position at each measurement point is adjusted to the previously determined width center position according to the movement of the steel plate. A method for measuring camber of a steel plate, characterized by measuring the amount of camber by overlapping a part of the camber.