JP7468476B2 - Method and apparatus for tracking cast slabs - Google Patents

Description

The present invention relates to a method and device for tracking the position of a cast piece during transportation by a transportation facility.

The multiple strands produced by continuous casting are transported to their respective designated destinations by a transport facility. Various methods have been proposed for tracking the strands (see, for example, Patent Document 1). In Patent Document 1, a strand detection sensor is installed at the front or rear end of each transport table to detect the presence or absence of a strand. The strand detection sensor detects the strand, detecting that the strand is present at the location where the transport table is installed, and tracking of the strand is performed. In addition, multiple cameras are installed at positions to capture images of each device in the process and the steel material on the line, and a tracking screen showing the operating status of each piece of equipment is displayed on the display. An operator then monitors whether each product is being transported correctly based on the captured images.

JP 2012-221460 A

In Patent Document 1, tracking errors may occur in which the tracking information differs from the actual position of the slab. In such cases, the operator constantly monitors the tracking screen, and if there is a difference between the tracking information and the contents displayed on the tracking screen, he or she performs operations to make the situation the same as the actual tracking target. However, this places an excessive burden on the operator, and there are cases in which the tracking error is overlooked.

The present invention has been made in consideration of the above problems, and aims to provide a method and device for tracking a slab that can automatically and accurately detect tracking errors in the slab.

[1] A method for tracking a cast piece, in which a continuously cast strand is cut into a plurality of cast pieces and the cut plurality of cast pieces are transported by a transport facility, and the positions of the plurality of cast pieces are detected, the method comprising the steps of:
a first tracking step of acquiring a position of the slab detected by a slab detection sensor installed in the transport facility as first tracking information;
a second tracking step of acquiring, as second tracking information, a position of the slab detected by analyzing an image of the transport facility;
a comparison step of comparing the first tracking information and the second tracking information;
The tracking method for a cast piece comprising the steps of:
[2] The method for tracking a slab according to [1], wherein the second tracking step includes setting an analysis area in the image for analyzing the presence or absence of the slab, and determining whether or not the slab is present in the analysis area.
[3] The method for tracking a cast piece according to [1] or [2], wherein, in the collation step, if the first tracking information and the second tracking information do not match, the first tracking information is corrected to the second tracking information.
[4] The method for tracking a strand according to any one of [1] to [3], wherein the first tracking step generates the first tracking information by combining strand identification information given to the strand in the order of cutting of the strand and a position of the strand.
[5] The method for tracking a strand according to any one of [1] to [4], wherein the second tracking step generates the second tracking information by combining cast piece identification information given to the cast piece in the order of cutting of the strand and a position of the cast piece.
[6] The second tracking step has a function of recognizing a dummy bar reflected in the image at the start of casting,
The method for tracking a cast piece according to any one of [1] to [4], further comprising the steps of: assigning cast piece identification information to the cast piece in an order in which the cast piece is transported after the dummy bar is recognized; and generating the second tracking information by combining the cast piece identification information and a position of the cast piece.
[7] In the second tracking step, the image is divided into two or more images in the conveying direction of the conveying facility, and each image is analyzed.
The method for tracking a slab according to claim [5] or [6], wherein when the second tracking information is generated from the analysis of a plurality of the images, the slab identification information is handed over as the slab moves from the upstream side to the downstream side of the conveying equipment.
[8] A slab tracking device that detects the positions of a plurality of slabs when a continuously cast strand is cut into a plurality of slabs and the cut slabs are transported by a transport facility, comprising:
a first tracking device that acquires a position of the slab detected by a slab detection sensor installed in the transport facility as first tracking information;
a second tracking device that acquires, as second tracking information, a position of the slab detected by analyzing an image of the transport facility;
a verification device for verifying the first tracking information and the second tracking information;
A casting tracking device having the same.

According to the present invention, a tracking error is detected by comparing the first tracking information of the slab obtained by the slab detection sensor with the second tracking information of the slab obtained by image analysis. This makes it possible to automatically detect tracking abnormalities caused by erroneous detection of the presence or absence of the slab on the conveying table or discrepancies in the tracking information.

1 is a schematic diagram showing an example of a continuous casting facility to which a slab tracking device of the present invention is applied. FIG. FIG. 1 is a functional block diagram showing a preferred embodiment of a casting tracking device of the present invention. FIG. 4 is a schematic diagram showing a state in which the torch tilting means tilts the cutting torch. FIG. 2 is a schematic diagram showing an example of a case where poor cutting of a cast piece occurs. FIG. 2 is a schematic diagram showing an example of a case where poor cutting of a cast piece occurs. FIG. 2 is a schematic diagram showing how two cast pieces are transported. FIG. 1 is a schematic diagram showing an example of a continuous casting facility to which another embodiment of a tracking device for a cast piece of the present invention is applied.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a schematic diagram showing an example of a continuous casting facility to which the slab tracking device of the present invention is applied. The continuous casting facility 1 in FIG. 1 includes a continuous casting machine 2 that continuously injects molten steel from a tundish into a mold to form a strand (shell-shaped slab) S0, a cutting device 3 that cuts the strand S0 drawn from the continuous casting machine 2, and a transport device 4 that transports the cut slab S. The continuous casting machine 2 produces a strand by drawing the slab from the mold while cooling it with pinch rollers. The cutting device 3 is, for example, a gas cutting machine, and cuts the strand to a predetermined length with a cutting torch.

The conveying equipment 4 conveys the strand S0 and cut pieces (slabs, blooms or billets) S to the target position, and has multiple conveying tables 4A-4E. Each of the conveying tables 4A-4E has a structure in which the roll shaft is connected to a driving device such as a motor via a sprocket and a chain, for example. The operation of the multiple conveying tables 4A-4E is controlled by a conveying control device 22 in FIG. 2, which will be described later.

The position of the cut strand S must be tracked during transportation until it is transported to the target position. Therefore, the continuous casting equipment 1 is equipped with a strand tracking device 10 that tracks the strand during transportation. Figure 2 is a functional block diagram showing a preferred embodiment of the strand tracking device of the present invention. The strand tracking device 10 in Figure 2 has a first tracking device 20 that generates first tracking information based on the detection results of the strand detection sensors 21A-21D, and a second tracking device 30 that generates second tracking information TN2 based on images captured by the imaging devices 31A and 31B.

The first tracking device 20 has a plurality of slab detection sensors 21A-21D installed on the conveying equipment 4, and a conveying control device 22 that generates first tracking information TN1 using the detection results of the plurality of slab detection sensors 21A-21D to control the operation of the conveying equipment 4. The plurality of slab detection sensors 21A-21D are installed on the entrance side of the conveying tables 4A-4E, respectively, and detect whether or not a slab is present on the conveying tables 4A-4E. Since the conveying tables 4B-4D are located between the respective slab detection sensors 21A-21D, the respective slab detection sensors 21A-21D are installed on the entrance side and exit side. Any method can be used as long as it detects the presence or absence of a slab, and for example, a method of detecting the presence or absence of a slab by turning on/off the passage of light or a method of detecting the presence or absence of a slab by magnetism can be used. In addition, the installation positions of the respective slab detection sensors 21A-21D are not limited to the above positions, and multiple sensors may be installed between the conveying tables 4A-4E.

The transport control device 22 operates the transport equipment 4 based on the cutting completion signal sent from the cutting device 3, and causes the cut pieces to be transported sequentially by the transport equipment 4. Note that, although an example is given in which the transport control device 22 generates the first tracking information TN1, an information generating device that generates the first tracking information may be provided as a separate configuration from the transport control device 22.

The transport control device 22 assigns slab identification information to the slabs in the order in which they are cut by the cutting device 3, and generates first tracking information TN1 including the slab identification information and the position of the slab. Specifically, when the transport control device 22 receives a cutting completion signal, it assigns slab identification information 1, 2, 3, ... to the slabs in consecutive order in the order in which they are cut. For ease of explanation, the example shows a case in which the slab identification information consists of consecutive numbers, but it may also consist of alphabetical order, symbols in a preset order, or a combination of these.

For example, when the slab detection sensor 21A detects the previous slab S1, the transport control device 22 generates first tracking information TN1 indicating that the slab S1 with slab identification information "1" is located at the position of the transport table 4B. When the slab S1 is transported and the slab detection sensor 21B detects the slab S1, the transport control device 22 updates the first tracking information TN1 of the slab S1 to indicate that the slab S1 with slab identification information "1" is located at the position on the transport table 4C. When the next slab S2 is transported and the slab detection sensor 21A detects the slab S2 for the second time, the transport control device 22 generates first tracking information TN1 indicating that the slab S2 with slab identification information "2" is located at the position on the transport table 4B. In this way, the first tracking information TN1 is generated for each slab S1, S2. Similarly, the transport control device 22 generates and updates the first tracking information TN1, which combines the position information of the transport table on which the slab is located and the slab identification information, according to the order in which the slab detection sensors 21B to 21D are detected.

The transport control device 22 controls the operation of the transport equipment 4 based on the detection results of the multiple slab detection sensors 21A-21D. For example, as shown in FIG. 1, when the slab S2 is cut by the cutting device and transported to the second transport table 4B, the slab detection sensor 21A detects the slab S2 and detects its entry onto the transport table 4B.

Next, when the second conveying table 4B conveys the slab S2 to the third conveying table 4C, the conveying control device 22 checks whether the previous slab S1 is present on the third conveying table 4C. If the previous slab S1 is present on the third conveying table 4C, the conveying control device 22 controls the slab S2 to stop on the second conveying table 4B. On the other hand, when the slab S1 passes through the detection range of the slab detection sensor 21C, the slab detection sensor 21C installed on the entry side of the fourth conveying table 4D turns from ON to OFF, and the conveying of the previous slab S1 to the fourth conveying table 4D is completed. At this time, the conveying control device 22 recognizes that the third conveying table 4C is empty, and controls the conveying of the slab S2 from the second conveying table 4B to the third conveying table 4C. Such conveying control is performed based on the first tracking information TN1 described above.

The second tracking device 30 in FIG. 2 includes imaging devices 31A and 31B that capture images of the slab transported by the transport equipment 4, and an image analysis unit 32 that analyzes the images captured by the imaging devices 31A and 31B to identify the position of the slab. The second tracking device 30 generates second tracking information TN2 based on the images captured by the imaging devices 31A and 31B. In FIG. 1 and FIG. 2, two imaging devices 31A and 31B capture images of the divided imaging area of the transport equipment 4. The imaging device 31A captures images of the transport tables 4A to 4C, and the imaging device 31B captures images of the transport tables 4D and 4E. The number of imaging devices is not limited to two, and may be three or more, or one imaging device may capture images of the entire transport equipment by zooming or swinging. The imaging devices 31A and 31B may be surveillance cameras installed to check whether the transport equipment is operating normally.

The imaging devices 31A and 31B capture images of the cast piece continuously or intermittently to obtain images. The images may be video or still images. FIG. 3 is a schematic diagram showing an example of an image captured by the imaging devices of FIGS. 1 and 2. As shown in FIG. 3, the imaging device 31B captures images of the conveying tables 4D and 4E in one image.

The image analysis unit 32 is composed of hardware resources such as a computer, analyzes the images acquired by the imaging devices 31A and 31B, and outputs the position of the slab S as second tracking information TN2. For example, in an image P as shown in FIG. 3, the areas of the transport tables 4D and 4E in the image P are preset as analysis areas in the image analysis unit 32. The image analysis unit 32 determines whether or not the slab S is present in the analysis areas, thereby determining whether or not the slab S is present in the transport tables 4D and 4E. Note that various known techniques can be used to identify the slab S.

When the image analysis unit 32 in FIG. 2 recognizes the slab S in the analysis area corresponding to the fourth conveying table 4D, it generates second tracking information TN2 indicating that the slab S is present on the conveying table 4D. Similarly, when the image analysis unit 32 recognizes the slab S in the analysis area corresponding to the conveying tables 4A to 4E, it generates second tracking information TN2 indicating that the slab is present on the conveying tables 4A to 4E.

The comparison device 40 compares the first tracking information with the second tracking information, and is configured with hardware resources such as a computer. The comparison device 40 may be configured with the same computer as the image analysis unit 32 or the transport control device 22, or may be configured with a separate computer. The comparison device 40 compares whether the positions of the cast pieces in the first tracking information TN1 and the second tracking information TN2 match. If the two match, it is determined that both the first tracking information TN1 and the second tracking information TN2 are correct.

On the other hand, if the first tracking information TN1 and the second tracking information TN2 do not match, the comparison device 40 identifies the second tracking information TN2 as correct, and the first tracking information TN1 of the transport control device 22 is corrected. The transport control device 22 then controls the operation of the transport facility 4 using the corrected first tracking information TN1. This allows operations to continue using the second tracking information, even if a tracking error occurs in the first tracking information TN1.

Although the example shows a case where the first tracking information TN1 is automatically corrected to the second tracking information TN2, it is also possible to simply output an abnormality signal indicating that a discrepancy has occurred between the first tracking information TN1 and the second tracking information TN2. The timing of the comparison in the comparison device 40 can be set appropriately. For example, when the first tracking information is generated or updated, it may be obtained and compared with the second tracking information. Alternatively, the second tracking information may be generated constantly, and the first tracking information TN1 may be compared with the second tracking information TN2 constantly.

A preferred embodiment of the method for tracking a strand of the present invention will be described with reference to Figures 1 to 3. First, in the transport control device 22 of the first tracking device 20, strand identification information is assigned to the strand S in the order in which the strand S0 is cut by the cutting device 3, using consecutive numbers. The strand S is then transported by the transport equipment 4 and detected by each strand detection sensor 21A to 21D, and information on the transport tables 4A to 4D on which it is placed is detected as position information of each strand. Then, first tracking information TN1 is generated by combining the strand identification information and the strand position information, and is sent to the collation device 40 (first tracking process).

In the second tracking device 30, the imaging devices 31A and 31B capture images of the transport tables 4A-4E indicated by the first tracking information TN1 to obtain images P. The images P are analyzed by the image analysis unit 32, which generates second tracking information indicating the presence or absence of the cast piece S on the transport tables 4A-4E and sends it to the collation device 40 (second tracking process).

The comparison device 40 compares the first tracking information with the second tracking information and determines whether there is an abnormality in the first tracking information (comparison process). If the first tracking information and the second tracking information do not match, the first tracking information is corrected assuming that the second tracking information is correct, and the transport control device 22 controls the transport equipment 4 based on the corrected first tracking information.

According to the above embodiment, first tracking information TN1 of the cast piece based on the cast piece detection sensors 21A-21D and second tracking information TN2 based on the images captured by the imaging devices 31A and 31B are acquired, and the position of the cast piece is tracked based on the first tracking information TN1 and the second tracking information TN2. This makes it possible to automatically and accurately detect tracking errors such as erroneous detection of the presence or absence of the cast piece S on the transport tables 4A-4D.

For example, when the slab detection sensor malfunctions or breaks down, the tracking information of the slab may move to a transport table different from the one where the slab is actually located. Specifically, the slab S2 has not actually passed through the entrance side of the transport table 4C, but the second slab detection sensor 4C may erroneously detect that the slab S2 has moved to the transport table 4C. As a result, a discrepancy occurs between the actual position of the slab S2 and the tracking information. In addition to malfunctions of the slab detection sensor, such malfunctions may also be caused by water vapor or dust.

In addition, when the cutting device 3 fails to cut the slab, a discrepancy occurs between the actual position of the slab S2 and the tracking information. Figures 4 and 5 are schematic diagrams showing an example of a case where the cutting device 3 fails to cut the slab. When the cutting of the slab is incomplete due to a defect in the cutting device 3, two or more slabs S1 and S2 are transported in a continuous state. The transport control device 22 operates the transport equipment 4 to move the slab S2 to the transport table 4B based on the cutting completion signal sent from the cutting device 3. However, since the slab S2 has not been cut off from the slab S1, the slab S2 moves in a continuous state with the slab S1 when the cutting device 3 completes cutting. Figure 6 is a schematic diagram showing how the two slabs S1 and S2 are transported. If the slabs S1 and S2 are completely cut, the slabs S1 and S2 are transported in a separated state as shown in Figure 6 (A). On the other hand, if the cutting of the slabs S1 and S2 is incomplete, as shown in FIG. 6(B), the two slabs S1 and S2 may be transported so that they fit within one transport table 4C. Or, as shown in FIG. 6(C), the two slabs S1 and S2 may be transported across multiple transport tables 4B and 4C. When the slab S2 passes through the slab detection sensors 21A and 21B together with the slab S1, it is erroneously recognized that the movement of one slab S1 is complete. This causes a discrepancy between the actual position of the slab S and the first tracking information TN1 from the slab detection sensors 21A and 21B.

Generally, an abnormality in the tracking information can be identified when the slab detection sensor does not detect any slabs even after the transport table has been operating for a certain period of time. However, an abnormality in the tracking information cannot be detected until the transport table is operated. Furthermore, the transport table is operated when the slabs are being moved. If an abnormality is detected at this time, the operation of the transport table must be stopped temporarily and the movement of the slabs interrupted, which will affect operations.

On the other hand, when the casting tracking device 10 of Figures 1 and 2 is used, the occurrence of a tracking error can be automatically detected with high accuracy by comparing the first tracking information TN1 with the second tracking information TN2, which indicates that the casting S2 is not present on the second conveying roller 4B. That is, in both cases of Figures 6 (B) and (C), when the casting S1 is conveyed in response to a conveying command for the casting S1, not only the casting S1 but also the casting S2 moves together. In other words, the casting S2 moves from the conveying table 4B on which the casting S2 should be placed. At that stage, a discrepancy occurs between the first tracking information TN1 and the second tracking information TN2, so the occurrence of a tracking error can be detected.

The slab identification information may be added not only to the first tracking information TN1 but also to the second tracking information TN2, so that the slab identification information can also be compared. For example, the transport control device 22 may transmit the slab identification information to the image analysis unit in FIG. 2 in parallel with the generation of the first tracking information TN1. Then, the second tracking information TN2 including the position of the slab and the slab identification information may be compared with the first tracking information TN1. The slab identification information does not have to be acquired from the transport control device 22. FIG. 7 is a schematic diagram showing an example of a continuous casting facility to which another embodiment of the slab tracking device of the present invention is applied. In FIG. 7, the same reference numerals are used to designate parts having the same configuration as those in the slab tracking device of FIG. 1, and the description thereof is omitted. As shown in FIG. 7, when the continuous casting facility 1 starts operating, a dummy bar 100 is inserted into the mold to close the lower end of the mold, and molten steel is poured into the mold. Then, the dummy bar 100 is pulled downward to start pulling out the slab.

The image analysis unit 32 in FIG. 2 recognizes the dummy bar 100 in the image P and recognizes the timing when the tail end of the dummy bar passes. The image analysis unit 32 then assigns slab identification information to the slab that is first captured in the image after the tail end of the dummy bar passes in order. At this time, when the conveying equipment 4 is divided into two or more images and acquired by the imaging devices 31A and 31B and analysis is performed on each image, the slab identification information is handed over as the slab S moves from the upstream side to the downstream side of the conveying equipment 4. The comparison device 40 then compares the first tracking information TN1 to which the slab identification information based on the operation of the cutting device 3 has been assigned with the second tracking information TN2 to which the slab identification information based on the recognition of the dummy bar 100 has been assigned.

In the second embodiment, as in the first embodiment, the occurrence of tracking anomalies due to erroneous detection or the like can be suppressed. Furthermore, by independently assigning the slab identification number using the second tracking device 30, anomalies can be detected even in the case of the first tracking information of the slab being swapped. For example, as shown in FIG. 1, the slab S1 is actually located on the transport table 4C, and the slab S2 is located on the transport table 4B. However, for some reason, the first tracking information TN1 may be swapped to indicate that the slab S2 is located on the transport table 4C, and the slab S1 is located on the transport table 4B. Once the first tracking information TN1 is swapped, it becomes difficult to detect an anomaly in the tracking information.

On the other hand, the first tracking device 20 and the second tracking device 30 each independently assign cast piece identification information to the cast piece, and the comparison device 40 compares not only the position information but also the cast piece identification information, so that abnormalities such as the above-mentioned tracking information being swapped can be detected and corrected.

The embodiments of the present invention are not limited to the above-mentioned embodiments and various modifications can be made. For example, the generation of the first tracking information is illustrated as being performed by the transport control device 22, but an information generating device that generates the first tracking information may be provided as a separate configuration from the transport control device 22. In addition, the cast piece identification information is illustrated as being numbered consecutively in the order of cutting according to the operation of the cutting device, but a sign bearing cast piece identification information such as numbers, letters, and symbols may be transported together with the cast piece, and the cast piece identification information may be acquired by analyzing the sign in the image analysis unit 32.

Reference Signs List 1 Continuous casting equipment 2 Continuous casting machine 3 Cutting device 4 Conveying equipment 4A to 4E Conveying table 10 Strand tracking device 20 First tracking device 21A to 21D Strand detection sensor 22 Conveying control device 30 Second tracking device 31A, 31B Imaging device 32 Image analysis unit 40 Verification device 100 Dummy bar P Image S, S1, S2 Strand TN1 First tracking information TN2 Second tracking information

Claims (8)

A method for tracking a cast piece, comprising the steps of: cutting a continuously cast strand into a plurality of cast pieces; and detecting positions of each of the plurality of cast pieces when the plurality of cut cast pieces are transported by a transport facility, the method comprising the steps of:
a first tracking step of acquiring a position of the slab detected by a slab detection sensor installed in the transport facility as first tracking information;
a second tracking step of acquiring, as second tracking information, a position of the slab detected by analyzing an image of the transport facility;
a verifying step of verifying the first tracking information and the second tracking information by a verifying device ;
The tracking method for a cast piece comprising the steps of: The method for tracking a slab according to claim 1, wherein the second tracking step sets an analysis area in the image for analyzing the presence or absence of the slab, and determines whether or not the slab is present in the analysis area. The method for tracking a cast piece according to claim 1 or 2, wherein, in the comparison process, if the first tracking information and the second tracking information do not match, the first tracking information is corrected to the second tracking information. The method for tracking a cast piece according to any one of claims 1 to 3, wherein the first tracking step generates the first tracking information by combining cast piece identification information given to the cast piece in the order of cutting of the strand and the position of the cast piece. 5. The method for tracking a strand according to claim 1, wherein the second tracking step generates the second tracking information by combining strand identification information, which is imparted to the strand in the order in which the strand is cut, with a position of the strand. The second tracking step includes:
In the second tracking step,
Recognizing the dummy bar reflected in the image at the start of casting,
The method for tracking a cast piece according to any one of claims 1 to 4, further comprising the steps of: assigning cast piece identification information to the cast piece in an order in which the cast piece is transported after the dummy bar is recognized; and generating the second tracking information by combining the cast piece identification information and a position of the cast piece. In the second tracking step, the image is divided into two or more images in the conveying direction of the conveying facility, and each image is analyzed.
The method for tracking a slab according to claim 5 or 6, wherein when the second tracking information is generated from analysis of a plurality of the images, the slab identification information is handed over as the slab moves from the upstream side to the downstream side of the conveying facility. A slab tracking device for detecting the positions of a plurality of slabs when a continuously cast strand is cut into a plurality of slabs and the cut slabs are transported by a transport facility, comprising:
a first tracking device that acquires a position of the slab detected by a slab detection sensor installed in the transport facility as first tracking information;
a second tracking device that acquires, as second tracking information, a position of the slab detected by analyzing an image of the transport facility;
a verification device for verifying the first tracking information and the second tracking information;
A casting tracking device having the same.

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