JPH03163303A - Method for detecting abnormality of measured data of optical plate-width meter - Google Patents

Abstract

PURPOSE:To detect the abnormality of measured data due to intrusion of foreign matter by operating the correlation coefficient between the changing amount of a plate width and the snaking amount of the plate based on the measured data of the plate width from an optical plate-width meter, and outputting abnormality information when the correlation between the changing amount of the plate width and the snaking amount of the plate becomes large. CONSTITUTION:The changing amount of a plate width and the snaking amount of the plate are inputted from a plate-width-meter controlling device 2. The correlation coefficient between these amounts is operated in an operating device 3. The result is compared with a preset threshold value. When it is judged that the correlation coefficient is larger than the threshold value, the correlation between the changing amount of the plate width and the snaking amount of the plate becomes large to some extent, and it can be judged that a foreign matter has intruded into the field of view of a plate-width meter 1. The abnormality information in the measured data of the plate width is outputted as an alarm. Meanwhile, when the correlation coefficient is smaller than the threshold value, it is judged that the measured data of the plate width is normal. Thus, the abnormality of the measured data due to the intrusion of the foreign matter can be readily detected by monitoring the correlation between the changing amount of the plate width and the snaking amount of the plate.

Description

Detailed Description of the Invention [Industrial Field of Application] The present invention relates to the measurement data of an optical plate width meter that non-contactly measures the width of a plate material such as a steel plate being rolled. The present invention relates to a method for detecting an abnormality caused by a foreign body intervening between the teeth.

[Prior Art] In general, there is an optical plate width meter as shown in FIG. 6 that measures the width of a plate material such as a steel plate during rolling in a non-contact manner.

The plate width meter 1 shown here is a self-luminous type steel plate width meter.
It consists of a pair of CCD cameras la and lb that detect the positions on both sides of the steel plate 4, which is the object of the plate width measurement. Each CC
The D cameras la and lb measure the position of the WS side (work side) edge 4a and the DS side (thigh movement side) edge 4b of the steel plate 4, respectively. Plate III measurement data can be obtained.

[Problems to be Solved by the Invention] By the way, in the plate width gauge 1 as described above, there is a possibility that the plate width gauge 1 may come into contact with foreign objects in mill accessories (pipes, bolts, etc.) during daily work, remodeling work, misroll processing, etc. , this foreign object is CCD
It may end up within the field of view of the CCD cameras la, lb between the cameras la, lb and the steel plate 4. Each CC
Since the field of view of the D cameras la and 1b is quite narrow, it is not easy to tell whether a foreign object has obstructed the field of view, and in that case, the board width gauge 1 will continue to output abnormal measurement data. This not only reduces the reliability of the board width meter 1, but also poses a risk of malfunction during automatic board width control.

For example, as shown in FIGS. 7(a) and 7(b), if the edge 4a on the WS side is covered with a foreign substance 5 (shaded area) and the edge 4b on the DS side is not covered, the edge 4a on the DS side
Regarding b, the actual position and the measured position match, but W
The position measured by the camera 1a on the S side is the position of the edge 5a of the foreign object 5, and does not match the actual position of the edge 4a. Therefore, inaccurate measurement data will be obtained, but this is not an error for the board width meter 1, so it will not be considered an error, and conventionally it has been impossible to detect abnormalities in measurement data in such situations. there were.

The present invention has been made to solve these problems, and is capable of detecting abnormalities in measurement data due to foreign object intervention, thereby improving measurement accuracy and reliability.
An object of the present invention is to provide a method for detecting abnormalities in measurement data of an optical plate width meter, which prevents malfunctions in automatic plate width control.

[Means for Solving the Problems] In order to achieve the above object, the method for detecting abnormality in measurement data of an optical plate width meter of the present invention detects the amount of plate width change based on the plate width measurement data by the optical plate width meter. and the amount of plate meandering, calculate the correlation coefficient between the obtained plate width change amount and the amount of plate meandering, compare the correlation coefficient with a set threshold value, and compare the correlation coefficient with the set threshold value. If the threshold value is exceeded, it is determined that a foreign object has intervened within the field of view of the optical sheet width meter, and abnormality information of the sheet width measurement data is output.

[Function] In the method for detecting abnormality in measurement data of the optical plate width meter described above,
When a foreign object enters the field of view of the optical board width meter, the presence of a foreign object is determined by utilizing the strong correlation between the board width data and the meandering data of the board to be measured. In other words, the correlation coefficient between the amount of sheet width change and the amount of sheet meandering based on the sheet width measurement data from the optical sheet width meter is calculated, and when this correlation coefficient exceeds the set threshold, the amount of sheet width change and the sheet meandering amount are calculated. When the correlation with the amount of meandering is considered to be strong to some extent, it is determined that a foreign object has intervened, and abnormality information of the board width measurement data is output.

[Embodiment of the Invention] Hereinafter, a method for detecting abnormality in measurement data of an optical plate width meter as an embodiment of the present invention will be explained with reference to the drawings.
The figure is a flowchart, FIG. 2 is a block diagram showing the apparatus structure for carrying out the method of this embodiment, and FIG. 3(a)
, (b) are diagrams for explaining an example of the field of view of the board width meter when a foreign object intervenes and meandering occurs, and Figures 4 (a) and (b) show the amount of change in board width and the amount of board meandering when a foreign object intervenes. 5(a) and 5(b) are graphs for explaining the means (fuzzy theory) for determining the threshold value for data abnormality determination.

First, the configuration of an apparatus to which the method of this embodiment is applied will be explained with reference to FIG. 2. In FIG. It consists of a pair of CCD cameras la and lb that detect positions. Each CCD camera la, lb is connected to the WS side edge 4a of the steel plate 4, similarly to the one shown in FIG.
, the position of the DS side edge 4b is measured. Reference numeral 2 denotes a plate width meter control device that calculates the plate width change amount and plate meandering amount of the steel plate 4 based on the plate edge position and camera position measured by each CCD camera la, lb, and outputs these; It operates according to the flow shown in Figure 1, which will be described later, and when it determines that there is an abnormality in the board width measurement data from the board width meter 1 due to the intervention of a foreign object, it outputs an alarm (abnormality information in the board width measurement data; for example, a buzzer sounds, a lamp lights up, etc.). It is a computing device that performs Here, the correlation between the amount of plate width change and the amount of plate meandering when a foreign object intervenes is shown in Figure 3 (a), (b) and Figure 4 (a), (b).
This is explained by: For example, as shown in Figure 3(a),
WS side field of view of board width meter 1 (field of view of CCD camera la)
Consider a case where the steel plate 4 meanders toward the WS side, as shown in FIGS. 3(a) and 3(b), with foreign matter entering and partially masking the area (hatched area). Before meandering, the edge measured on the WS side is the edge 5a of the foreign object 5, and the edge measured on the DS side is the edge 4b of the steel plate 4.
The edge measured on the S side remains the same edge 5a of the foreign object 5 as before meandering. The edge measured on the DS side is the edge 4d of the moved steel plate 4. In other words, when the steel plate 4 meanders towards the WS side, the plate width is measured as if it had become narrower, while when it meandered towards the DS side, it is measured as if it had become wider. however,
In both cases, the width is narrower than the actual board width.

In such a case, the actual waveforms of the plate width change amount and plate meandering amount determined by the plate width meter control device 2 are as shown in FIG. 4(a) and
The result is as shown in (b). As is clear from these figures, when the field of view of the plate width gauge 1 is masked by the foreign object 5, the correlation between the amount of plate width change and the amount of plate meandering becomes very strong;
In a normal case without foreign body intervention, there is no correlation between the amount of plate width change and the amount of plate meandering.

The present invention utilizes such correlation characteristics to determine abnormalities in plate width measurement data due to foreign object intervention. Next, the operation of the arithmetic unit 3, that is, the portion related to the features of the present invention will be explained with reference to FIG. As shown in FIG. 1, when the calculation device 3 receives the strip width change amount and the strip meandering amount from the strip width meter control device 2 (steps SL, S2), it calculates these strip width change amount and strip meandering amount. Calculate the correlation coefficient with (step S
3) Compare with a preset threshold (step S
4). At this time, as a means of determining the threshold value for data abnormality judgment, for example, a fuzzy theory using membership functions as shown in Figures 5(a) and (b) for the correlation coefficient and plate width deviation, respectively, is used. Apply.

As a result of the comparison in step S4, if it is determined that the correlation coefficient is larger than the threshold value, the correlation between the plate width change amount and the plate meandering amount is strong to some extent, and as described above, the foreign object 5 It can be determined that the object has intervened in a total of 1 visual fields, and abnormal information on the board width measurement data is output as an alarm (step S5). On the other hand, if the correlation coefficient is less than the threshold value, it is determined that the board width measurement data is normal (step S
6).

As described above, according to the method of this embodiment, by monitoring the correlation between the amount of sheet width change and the amount of sheet meandering, abnormalities in sheet width measurement data due to foreign matter intervention can be easily detected, thereby improving measurement accuracy. Reliability is greatly improved, and malfunctions in automatic plate width control are reliably prevented. [Effects of the Invention] As detailed above, according to the measurement data abnormality detection method of the optical plate width meter of the present invention, the amount of plate width change and plate meandering based on the plate width measurement data from the optical plate width meter can be detected. Calculate the correlation coefficient with the plate width measurement data, and when this correlation coefficient exceeds a set threshold and the correlation between the plate width change amount and plate meandering amount becomes strong to a certain extent, abnormal information on the plate width measurement data is output. This makes it possible to detect abnormalities in measurement data due to foreign matter intervention, improve measurement accuracy and reliability, and prevent malfunctions in automatic board width control.

[Brief explanation of the drawing]

Figures 1 to 5 show a method for detecting abnormalities in measurement data of an optical plate width meter as an embodiment of the present invention. Figure 2 is a flowchart of the method, and Figure 2 is a method for implementing the method of this embodiment. 3(a) and (b) are diagrams for explaining an example of the field of view of the board width meter when foreign matter intervenes and meandering occurs, and FIG. 4(a), (b) 5 is a graph showing the correlation between the amount of change in sheet width and the amount of sheet meandering when a foreign object intervenes using an actual waveform, and FIGS. Fig. 6 is a configuration diagram showing a general optical plate width meter, Fig. 7(a), (
b) is a diagram for explaining an example of the visual field state of the board width meter when a foreign object intervenes. In the figure, 1-optical steel plate width meter, la, 1b-C
CD camera, 21 plate width meter control device, 31 calculation device, 4
1 steel plate, 4a to 4d-edge, 5- foreign object, 5a-1 edge.

Claims (1)

[Claims] After determining the amount of sheet width change and the amount of sheet meandering based on the sheet width measurement data using the optical sheet width meter, calculate the correlation coefficient between the determined amount of sheet width change and the amount of sheet meandering, and calculate the correlation coefficient. and a set threshold value, and if the correlation coefficient exceeds the set threshold value, it is determined that a foreign object has intervened within the field of view of the optical sheet width meter, and an abnormality in the sheet width measurement data is determined. A method for detecting abnormality in measurement data of an optical plate width meter, characterized by outputting information.