JPS5829558A - Detector for melt surface of continuous casting machine - Google Patents

Abstract

PURPOSE:To detect a melt surface accurately despite the presence of oscillations by determining one point of a member fixed around the melt level as a reference, and subjecting the segment spaced by a predetermined quantity on an image plane where the melt surface moves vertically from said point to signal processing thereby detecting the melt surface. CONSTITUTION:A camera 5 picks up the images of the points A, B on the inside surface of a mold 3 and the reference point 6 fixed on the wall of the mold 3. The height of a melt surface 4 is confirmed by an image processor 7 from the ratio at which molten metal is filled out of the changing range of the surface 4 which is an object, that is, the length of the segment A, B, and the output of the melt level is produced. The image picked up with the camera 5 is projected on a monitor device 8. Even when the set position of the camera 5 deviates or even when there are oscillations, always accurate detecting range for the melt surface is detected as far as the point 6 and the detecting range for the melt surface are within the image plane, whereby the melt surface is detected.

Description

[Detailed description of the invention] The present invention relates to a hot water level detection device for a continuous casting machine.

In a continuous casting machine that continuously transforms metal into slabs, overflow occurs if the amount of poured metal is greater than the amount of metal withdrawn.

On the contrary, if the amount of molten metal poured is large, breakout will occur due to insufficient cooling length, so the amount of molten metal poured and the amount of molten metal withdrawn must be in equilibrium, and the surface position of the molten metal (molten metal surface height) is It is necessary to maintain an appropriate position within the mold. Therefore, in order to operate a continuous casting machine, the height of the molten metal must be detected by some method, and either or both of the pouring speed and withdrawal speed must be adjusted. Must.

Specific methods for detecting the hot water level include visual inspection, radiation, thermocouple,
There are methods such as non-contact displacement meters and video processing, but among these, methods that rely on video processing are attracting attention as methods with excellent safety, operability, and coordination due to the development of electronic equipment in recent years. A method that relies on video processing uses an imaging device (specifically, a TV
In order to prevent cameras, etc. (hereinafter referred to as cameras) from being exposed to adverse environments such as high temperatures and splashes, and to install them so that they do not become a hindrance to work, it is necessary to install them several meters from the pouring hole. On the other hand, in order to detect the hot water level with high precision, it is necessary to narrow down the angle of view as much as possible to project the hot water level as large as possible on the screen. In other words, you will be viewing a narrow area from a far away position, and you will need to be sure of the relative position of the camera and the hot water surface.

However, since the camera stand is generally rotated and moved for operational reasons, the positional accuracy with respect to the sprue is
This results in deterioration, and considerable adjustment time is required to project the sprue at a predetermined position on the screen. In addition, the camera stand may also vibrate due to the vibrations of peripheral equipment, and the hot water level may be detected as if it were moving.

The present invention aims to solve the above-mentioned problem, and the relative position of the J1 pot, U, nozzle, mold, etc. shown on the screen with respect to the hot water surface is independent of the camera installation position and vibration. A point on the machine is set as a reference point, and signal processing is performed at a position separated by a distance Mf consisting of four reference points on both sides photographed by a camera to determine the quantitative ratio of signals indicating whether molten metal is present or not. ": The height of the water level has been detected! I
K sign.

Embodiments of the present invention will be explained below using drawings.

Figure 1 U1 does not show the vicinity of the pouring port 1if of the continuous casting machine and the installation situation of the camera. The molten metal in the ladle 1 is poured into a mold 3 through a nozzle 2, cooled and solidified, and then pulled out downward by a drawing device (not shown). ti', Qm and the amount of withdrawal are controlled to be balanced to form a molten metal level 4 in the mold 3. The camera 5 takes pictures of the inner surface of the mold 3, points A, 3, and the reference point 6, and the image processing device 7 records the percentage of the molten metal filled in the target melt level change range, that is, A.
Check the height of the hot water level and output the hot water level output using the line segment length of T3. The image captured by the camera 5 is displayed on a monitor device 8.

FIG. 2 shows a screen 9 taken by the camera 5. Image Studio, T
! I'! This method determines whether a position on the screen is brighter or darker than a predetermined threshold value, and assumes that the bright area is filled with molten metal. Therefore, in order to detect the height of the hot water level, the range where the hot water level changes should be set to the coordinates of "2" on the screen:
X from 11 to the screen standard in Figure 2.
Image processing will be performed in the hot water level detection range centered on the wheelbase distance (1iifX and Y-axis distance)'. However, as mentioned above, if the installation position of the camera shifts or vibrates, the actual position where the hot water level should be detected and the position where the hot water level is detected by image processing on the screen will not match, and the hot water level will not be detected correctly. be. Therefore, by setting the position of the device displayed on the screen at -71 (distance A block diagram of the operation is shown. First, the reference position detection circuit 12 detects the coordinates x/y/ of the reference position on the screen from the image signal, and
The coordinate calculation circuit 13.14 calculates X, Y from x/y7 and the distance x, y from the reference point knitted by IJ-1, and the hot water surface height calculation circuit 15 calculates X, Y on the screen.
According to the present invention, even if the camera position shifts or there is vibration, the reference point can be maintained even if the camera position shifts or if there is vibration. As long as the hot water level detection range is within the screen, it is possible to always accurately capture the hot water level detection range and perform hot water level detection.

The reference position detection circuit and hot water level height calculation circuit are high-speed A/I
) This is possible by using a converter and a microphone combicoder.

Although we have explained the case where the reference point is one point, if the reference point is two points (
(or above), it becomes possible to correct the distortion of the camera's angle of view on the XY plane.'' Needless to say.

[Brief explanation of the drawing]

Claims (1)

[Claims] 1° In a hot water level detection device that detects the hot water level of molten metal from a video image showing the hot water surface, a screen on which the hot water level rises and falls from a point on a fixed member around the hot water surface. −
A melt level detection device for a continuous casting machine, characterized in that the melt level is detected by signal processing of line segments separated by a predetermined amount of 1.