Steel plates, steel plate management systems, and management methods.

Abstract

This invention provides a steel plate, a steel plate management system, and a management method that allow for the tracking of unique identification numbers until the product is processed into a finished product. [Solution] The steel plate 10 has a product portion 11 used in the product and a management portion 12 that is surplus after removing the product portion 11, and is divided into the product portion 11 and the management portion 12 in a plan view, and a symbol 13 indicating a unique identification number N is directly formed on the management portion 12. The management system 20 is equipped with a shape acquisition device 21 that acquires shape data 40 indicating the shape of the symbol 13, and the calculation device 22 is configured to perform data processing that converts the shape data 40 acquired by the shape acquisition device 21 into an identification number N.

Description

Technical Field

[0001] The present invention relates to a steel plate, a management system for steel plates, and a management method. More specifically, the present invention relates to a steel plate, a management system for steel plates, and a management method that can grasp a unique identification number until the steel plate is processed into a product.

Background Art

[0002] For the management of a large number of steel plates in steel mills and steel material warehouses, the unique identification numbers possessed by each steel plate are used. The identification numbers are indicated by imprints engraved on the edge surface (side surface) of the steel plate, stencils applied to the plate surface (upper surface) of the steel plate, and labels attached to the edge surface or plate surface. Various methods for automatically reading this identification number have been proposed (see Patent Documents 1 and 2).

[0003] However, since the imprint using characters indicating the identification number is engraved on the edge surface of the steel plate and is small in size, it is extremely difficult to automatically grasp the identification number. The identification number indicated by the stencil disappears when a post-treatment (for example, blasting treatment) is performed, and thus the identification number cannot be recognized when the steel plate is processed. Therefore, when using a stencil to indicate the identification number, it is essential to use it in combination with an imprint. Labels are likely to be damaged by contact between steel plates during transportation. Thus, with the identification numbers indicated by existing methods, a situation where the identification number cannot be read occurs from when the steel plate is produced until it is processed into a product. Therefore, there is room for improvement in grasping the unique identification number possessed by the steel plate until it is processed into a product.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

[0005] The object of the present invention is to provide a steel plate, a steel plate management system, and a management method that can determine a unique identification number until the product is processed into a finished product. [Means for solving the problem]

[0006] The steel sheet of the present invention, which achieves the above objective, has a product portion used in the product and a management portion that is surplus after removing the product portion, and is divided into the product portion and the management portion in a plan view, and is characterized in that a symbol indicating a unique identification number is directly formed on the surface of the management portion.

[0007] The steel plate management system of the present invention is characterized in that it includes a calculation device that grasps a unique identification number possessed by a steel plate, and the steel plate is managed according to the grasped identification number, the steel plate is divided in plan view into a product portion used in a product and a management portion which is surplus excluding the product portion, a symbol indicating the identification number is directly formed on the surface of the management portion of the steel plate, and a shape acquisition device is provided to acquire shape data indicating the shape of the symbol, and the calculation device is configured to perform data processing to convert the shape data acquired by the shape acquisition device into the identification number.

[0008] The present invention relates to a method for managing steel plates, which involves using a computing device to determine a unique identification number of a steel plate and managing the steel plate using the determined identification number. The method is characterized in that, in a plan view, the steel plate is divided into a product portion used in a product and a management portion which is surplus after removing the product portion, a symbol indicating the identification number is directly formed on the surface of the management portion, a shape acquisition device acquires shape data indicating the shape of the symbol, and the shape acquisition device performs data processing to convert the shape data acquired by the shape acquisition device into the identification number using the computing device. [Effects of the Invention]

[0009] According to the present invention, the symbols formed directly on the surface of the excess control portion of the steel plate will not disappear from the steel plate until the product portion and the control portion are separated when the steel plate is processed into a product. Therefore, the unique identification number of the steel plate can be determined based on these symbols until it is processed into a product. [Brief explanation of the drawing]

[0010] [Figure 1] This is an explanatory diagram illustrating an embodiment of a steel plate and its management system. [Figure 2] This is an explanatory diagram illustrating management data. [Figure 3] This is an explanatory diagram illustrating a portion of a steel plate in a plan view. [Figure 4] This is an explanatory diagram illustrating a management system installed on a crane. [Figure 5] This is an explanatory diagram illustrating the placement of a shape acquisition device installed on a crane, as shown in plan view. [Figure 6] This is a flowchart illustrating the procedure of an embodiment of a steel plate management method. [Figure 7] This is an explanatory diagram illustrating the shape of symbols calculated based on shape data. [Figure 8] This is an explanatory diagram illustrating a modified example 1 of the steel plate embodiment. [Figure 9] This is an explanatory diagram illustrating a modified example 2 of the steel plate embodiment. [Figure 10] This is an explanatory diagram illustrating the placement of a shape acquisition device installed on a crane, shown in a side view. [Modes for carrying out the invention]

[0011] The steel plate, its management system, and its management method according to the present invention will be described below based on the embodiments shown in the figures.

[0012] The embodiment of the steel plate 10 illustrated in Figure 1 is produced and managed in a steel mill or steel warehouse, and shipped to clients such as manufacturers and processors for processing into products. The steel plate 10 has a product area 11 and a management area 12 that are separated in plan view (plate surface view, thickness direction view). The steel plate 10 has a symbol 13 indicating the unique identification number N of the steel plate 10 directly formed on the management area 12.

[0013] A management method for steel plates 10 is implemented using an embodiment of the management system 20. This management system 20 and management method are used to determine the unique identification number N of the steel plate 10. More specifically, this management method acquires shape data 40 indicating the shape of symbol 13 using a shape acquisition device 21, and performs data processing to convert the shape data 40 into an identification number N using a calculation device 22, thereby determining the unique identification number N of the steel plate 10. Then, using this determined identification number N and pre-stored management data 30, various information about the steel plate 10 is identified.

[0014] The management data 30 illustrated in Figure 2 is stored in the auxiliary storage unit of the computing unit 22. The management data 30 is used for managing the steel plates 10, and for each identification number N (N1, N2, ..., Nn) assigned to the numerous steel plates 10 managed in steel mills and steel warehouses, it contains multiple types of information such as dimensions (which may be the dimensions of the product part 11), raw material name, delivery destination (client name), and current location. In other words, in the management data 30, multiple types of information related to the steel plate 10 are linked to the identification number N. Therefore, by knowing the identification number N written on the steel plate 10, it is possible to obtain the information necessary for managing the steel plate 10. The current location is, for example, the planar position in the steel mill or steel warehouse and the number of layers stacked at that position (number of layers from the bottom layer). In this way, managing a large number of steel plates 10 using management data 30, in which the identification number N is linked to information about the steel plate 10, is advantageous for improving efficiency in steel mills and steel warehouses. Therefore, it is necessary to determine the unique identification number N that the steel plate 10 possesses.

[0015] Next, the details of the steel plate 10 will be described.

[0016] The steel plate 10 illustrated in FIG. 3 is a steel material processed into a plate shape from a steel ingot (slab). The steel plate 10 is classified into four types: thin plate (thickness less than 3 mm), medium plate (thickness 3 mm or more and less than 6 mm), thick plate (thickness 6 mm or more and less than 150 mm), and extremely thick plate (thickness 150 mm or more) according to the thickness. The steel plate 10 also includes surface-treated steel plates such as galvanized steel plates, tin-plated steel plates, tin-free steel plates, vinyl chloride-coated steel plates, copper-plated steel plates, and painted steel plates that have been subjected to surface treatment processing. In FIG. 3, the surface orthogonal to the front and back directions of the figure of the steel plate 10 is the plate surface, and the other surfaces are edge surfaces (surfaces orthogonal to the plate surface).

[0017] The steel plate 10 is assigned a unique identification number N and is managed according to this identification number N. The identification number N is different for each steel plate 10. The identification number N can be set arbitrarily. For the identification number N, mainly numbers can be used, but letters and special characters (such as " " (space), "-" (hyphen), "." (period), etc.) can also be used.

[0018] The product part 11 occupies most of the steel plate 10 in plan view, has the shape and dimensions desired by the client, and is used in the product. The product part 11 is transported from the steel mill or steel material warehouse to the client, and after undergoing post-treatment by the client, it is processed as a product or a part of the product. The shape of the product part 11 can use any shape, but mainly forms a rectangle in plan view. Exceptionally, there may be cases where the shape of the product part 11 is other than a rectangle. There may be multiple product parts 11 on one steel plate 10. The dimensions of the product part 11 (length, width, thickness when the shape is a rectangle) can be set as appropriate.

[0019] The management part 12 indicates the surplus part of the steel plate 10 excluding the product part 11. That is, the management part 12 is a part that is not used as a product and is an unnecessary part as the steel material desired by the client. The management part 12 is only used for the management of the steel plate 10.

[0020] A symbol 13, representing the unique identification number N of the steel plate 10, is directly formed on the surface of the control area 12. Direct formation means that the symbol is formed by cutting or grinding the control area 12. As mentioned above, the control area 12 is a part that is not processed as a product, unlike the product area 11. Therefore, directly forming the symbol 13 on the control area 12 does not affect the product area 11. In addition, because the symbol 13 is directly formed on the surface of the control area 12, the formed symbol 13 will not disappear from the steel plate 10 until the control area 12 is separated from the product area 11, thus avoiding a situation where the symbol 13 cannot be identified. Furthermore, because the surface of the control area 12 is larger than the edge surface, the symbol 13 can be formed on its surface in a larger and more readable manner.

[0021] In one example of a steel plate 10 manufacturing process that includes a control section 12, the length of the product section 11 is extended by the length of the control section 12 to produce a single steel plate 10, after which the symbol 13 is formed on the control section 12. In this manufacturing process, the control section 12 only needs to be considered when shearing the steel material that has undergone the rolling process to the desired dimensions, there is no need to significantly change the manufacturing process, and the time required for the manufacturing process is roughly the same as the time required for the manufacturing process of conventional steel plates. In another example of a manufacturing process, the product section 11 and the control section 12 are manufactured separately, and then the product section 11 and the control section 12 are joined together to produce a single steel plate 10. In this manufacturing process, the number of manufacturing steps increases due to the process of joining the product section 11 and the control section 12, but it has the advantage that the symbol 13 can be formed on the control section 12 in advance on a separate line from the product section 11. Therefore, although the number of lines used in the production process increases, the increase in time required for the joining process can be covered by the time required for forming the symbol 13 on a separate line, resulting in a time roughly equivalent to that required for the production process of conventional steel sheets. Furthermore, when the product part 11 and the control part 12 are produced separately, the raw materials for the product part 11 and the control part 12 may be different. In other words, leftover steel material from the production process of the steel sheet 10 can be used for the control part 12. The production process can be selected as appropriate.

[0022] Even if a control portion 12 is provided, it is desirable that the combined shape of the product portion 11 and the control portion 12 forms a rectangle (including a square) in plan view, similar to conventional steel plates. It is also possible for the control portion 12 to be composed of a protruding piece, resulting in a convex polygon when the product portion 11 and the control portion 12 are combined. However, the part protruding from the rectangle is easily damaged and may damage other steel plates. Therefore, by ensuring that the combined shape of the product portion 11 and the control portion 12 forms a rectangle, the control portion 12 does not protrude, thus avoiding damage. Furthermore, it becomes possible to handle it in the same way as conventional steel plates without a control portion 12. The shape of the control portion 12 is a rectangle with the product portion 11 removed. Specifically, in plan view, the steel plate 10 forms a rectangle with the long side of the rectangle of the product portion 11 extended, and this extended part is the control portion 12. The control portion 12 is preferably located on the edge of one of the short sides of the steel plate 10. Since the control area 12 is located on the edge of one of the short sides of the steel plate 10, the location of the control area 12 is generally consistent across many steel plates 10, which is advantageous for searching for the symbol 13 formed on the control area 12. Furthermore, it is desirable for the control area 12 to occupy the entire edge. Occupying the entire edge increases the area of ​​the control area 12 in plan view.

[0023] The size of the control area 12 does not need to be limited in plan view as long as the symbol 13 can be formed, but it is preferable that its size be as small as possible. Specifically, the control area 12 is a rectangle with the short side of the steel plate 10 as its long side, and it is preferable that the length of the short side of the rectangle is longer than the thickness of the steel plate 10. The length of the short side is, for example, 10 mm or more, more preferably 25 mm or more, with an upper limit of, for example, 100 mm. By having the control area 12 in this shape, it becomes possible to make the symbol 13 formed on the control area 12 larger than the markings or labels that are marked on the edge surface of the steel plate 10 in the conventional technology, which is advantageous for identifying the symbol 13. In addition, by suppressing the increase in weight and length of the steel plate 10 due to the addition of the control area 12, it is advantageous for transportation and shipping.

[0024] Symbol 13 represents the unique identification number N of the steel plate 10. Symbol 13 can also be a character (such as an alphanumeric character) representing the identification number N. However, directly forming a character representing the identification number N on the control area 12 is time-consuming and difficult to recognize. Therefore, it is preferable to use a figure or mark other than a character that can be converted to the identification number N for symbol 13. Using a figure or mark other than a character as symbol 13 is advantageous for reading symbol 13.

[0025] More specifically, symbol 13 has multiple through holes 14, and the size and position of each through hole 14 indicate the identification number N. The shape of the through holes 14 in plan view is not particularly limited as long as it is a shape acquired by the shape acquisition device 21 described later. The shape of the through holes 14 can be, for example, a linear notch (slit) extending perpendicularly from the edge surface in a plan view, a circle (including an ellipse), or a polygon. When symbol 13 has multiple through holes 14, multiple gaps 15 are formed between adjacent through holes 14. In some cases, these gaps 15 constitute symbol 13, but in other cases, the gaps 15 do not constitute symbol 13.

[0026] More specifically, symbol 13 has multiple through-holes 14 penetrating the control area 12 in a direction perpendicular to the plate surface (the thickness direction of the steel plate 10), and multiple gaps 15 between adjacent through-holes 14. Because symbol 13 has multiple through-holes 14, it can be identified not only from the top surface of the steel plate 10 but also from the bottom surface. Furthermore, the through-holes 14 can be formed relatively easily in the steel plate 10, which is advantageous in simplifying the processing required to form symbol 13. By forming symbol 13 on the control area 12, it becomes unnecessary to stamp or stencil the identification number N on the edge surface of the steel plate 10. Instead of performing these stamping or stenciling steps, the process of forming symbol 13 can be performed. In other words, the number of steps in the steel plate 10 manufacturing process does not increase significantly in order to form symbol 13.

[0027] Furthermore, it is more desirable that the through-hole 14 is recessed inward from the edge surface of the steel plate 10. By recessing the through-hole 14 inward from the edge surface in this way, the symbol 13 will appear not only on the top and bottom surfaces of the control area 12, but also on the edge surface. Therefore, the symbol 13 can be confirmed even when viewed from the edge surface. This allows for the confirmation of each symbol 13 even when numerous steel plates 10 are stacked in a steel mill or steel warehouse, as long as the edge surface is visible.

[0028] Symbol 13 is not particularly limited as long as it can represent the identification number N by the size and position of each through-hole 14. Symbol 13 mimics, for example, a p-adic number (where a predetermined number p is the base and the sum of the powers of the base represents the number). In the case of a binary number, the identification number N can be represented in binary by the arrangement of the through-holes 14 and gaps 15, with the through-holes 14 being "0" and the gaps 15 being "1". However, in the case of p-adic numbers of decimal or less, the number of through-holes 14 formed in the management part 12 increases, and in the case of p-adic numbers greater than decimal, it is necessary to classify the size of the through-holes 14 and the size of the gaps 15 more finely. Also, in p-adic numbers, the correct symbol 13 can only be read in one direction. Therefore, it is more desirable for symbol 13 to mimic a known one-dimensional code (barcode) or two-dimensional code (matrix code, stack code). One-dimensional and two-dimensional codes have no distinction between front and back, top and bottom, or left and right, and are not affected by the reading situation. Furthermore, one-dimensional and two-dimensional codes represent each character with a relatively simple structure consisting of bars (black lines), dots (black dots), and spaces (areas without black lines or dots). In addition, one-dimensional and two-dimensional codes have check digits, which reduces the probability of misrecognition. Therefore, by having symbol 13 mimic a one-dimensional or two-dimensional code, the influence of the circumstances under which symbol 13 is read can be eliminated, which is advantageous for more reliably determining the identification number N. Moreover, it becomes possible to use simple shapes for the through-hole 14, making the process of forming symbol 13 as simple as possible.

[0029] Symbol 13, which mimics a one-dimensional code, is described in detail below. Symbol 13 consists of multiple through-holes 14 arranged at intervals in one direction. Symbol 13 mimics a one-dimensional code through each through-hole 14 and each gap 15. Either each through-hole 14 or each gap 15 corresponds to a bar (black line) in a one-dimensional code, and the other corresponds to a space (white line). Symbol 13 can use the barcode symbol system standardized in JIS X0502 to X0508 as a one-dimensional code.

[0030] Symbol 13 is difficult to read directly as a one-dimensional code using a barcode reader or scanner because the through-hole 14 and the gap 15 are not distinguished by color coding. Also, since symbol 13 is formed by processing steel plate 10, it is difficult to use the dimensions of one-dimensional codes standardized in JIS X502 to X508. Therefore, symbol 13 mimics a one-dimensional code by representing the size (width) of the through-hole 14 and the size (width) of the gap 15 with the ratio of the width of bars and spaces in a one-dimensional code. In other words, in symbol 13, the width of the bars and spaces in a one-dimensional code is used as the standard, and the width is increased by a predetermined ratio to determine the size of the through-hole 14 and the gap 15.

[0031] The size of the through-holes 14 and the gaps 15 indicates the length in the direction of arrangement of the multiple through-holes 14. If the through-holes 14 are composed of notches, the size of the through-holes 14 is indicated by the width of the notches, and the size of the gaps 15 is indicated by the width of the space between adjacent notches. Also, if the through-holes 14 are composed of circles, the size of the through-holes 14 is indicated by the diameter of the circles.

[0032] Furthermore, if symbol 13 is a binary number, it can also be represented by an arrangement of multiple through-holes 14 and multiple gaps 15 of the same shape. Also, if symbol 13 is a binary number, a row of through-holes 14 representing "0" and a row of through-holes 14 representing "1" can be used. In this way, the through-holes 14 and gaps 15 are appropriately selected in terms of shape, dimensions, and arrangement according to symbol 13.

[0033] Next, we will describe in detail the management system 20 and management method for reading the unique identification number N of the steel plate 10.

[0034] The management system 20 illustrated in Figure 4 comprises a shape acquisition device 21 and a calculation device 22. The shape acquisition device 21 and the calculation device 22 may be directly connected via signal lines, or they may be connected via a predetermined network. Furthermore, the management system 20 is not limited to a configuration in which the shape acquisition device 21 and the calculation device 22 are separate components; it can also be configured as a handheld device integrating the shape acquisition device 21 and the calculation device 22. The management system 20 may have multiple shape acquisition devices 21 connected to one calculation device 22. In addition, the management system 20 may be configured so that multiple calculation devices 22 are connected via a network and can communicate with each other.

[0035] The shape acquisition device 21 only needs to be able to read the shape of the symbol 13 and acquire shape data 40 that represents that shape, and can use known LiDAR (Light Detection and Ranging) sensors, millimeter-wave radar, cameras, etc. The shape acquisition device 21 may be a combination of several of these devices. However, with a camera, because the thickness of the steel plate 10 is thin, when multiple plates are stacked, the boundaries of the symbol 13 may become unclear, and there is a risk that shape data 40 that represents the shape of the symbol 13 cannot be acquired. Also, when multiple symbols 13 are captured in the image, it is difficult to distinguish the symbol 13 on the top steel plate 10. Therefore, the shape acquisition device 21 should be able to read the irregularities caused by the formation of the symbol 13 on the plate surface of the control area 12 as a shape, and devices other than cameras are preferred.

[0036] The shape acquisition device 21 is installed on a crane 50 that handles the steel plates 10. The crane 50 can be any known type of crane, such as a gantry crane or a transfer crane (yard crane). The shape acquisition device 21 is installed, for example, on the lifting equipment 51 or leg structure 52 of the crane 50. The shape acquisition device 21 reads a symbol 13 formed on the surface of the control section 12 of the steel plate 10, which is located on the top layer of multiple steel plates 10 stacked on a pallet 53 placed between the legs of the leg structure 52 of the crane 50, and acquires shape data 40 that shows the shape of the symbol 13. Therefore, the shape acquisition device 21 is installed at a position higher than the top layer of multiple steel plates 10 stacked on the pallet 53, and is irradiated with electromagnetic waves such as laser beams in a diagonal downward direction, or the optical axis of the camera is pointed diagonally downward.

[0037] The range over which the shape acquisition device 21 acquires shape data 40 may be two-dimensional, but it is preferable that the range be three-dimensional. For example, in a shape acquisition device 21 using a LiDAR sensor, the scanning range is three-dimensional, and the horizontal scanning range should include both ends of the pallet 53 in the short direction in a plan view, and the vertical scanning range should include both ends of the pallet 53 in the long direction in a plan view. If multiple shape acquisition devices 21 are installed on the crane 50, the vertical scanning range should include one end of the pallet 53 in the long direction from the center position of the pallet 53.

[0038] It is more desirable that the range within which the shape acquisition device 21 acquires shape data 40 includes the edges of the multiple steel plates 10 stacked on the pallet 53 (the edges of each control section 12). If the vertical scanning range of the shape acquisition device 21 includes one end of the pallet 53 in the longitudinal direction in a plan view, the edges of the multiple steel plates 10 stacked on the pallet 53 will be included in the acquisition range. This makes it possible for the shape acquisition device 21 to acquire shape data 40 showing the shape of the symbols 13 formed on the edges of the control sections 12, and it is advantageous for acquiring the shape more accurately by using shape data 40 showing the shape of each symbol 13 formed on both the plate surface and the edge surface. In addition, the shape acquisition device 21 can acquire shape data 40 showing the shape of each symbol 13 directly formed on the edges of each control section 12 of the multiple steel plates 10 stacked on the pallet 53 at once. This makes it possible to grasp the symbols 13 formed on steel plates 10 other than the topmost steel plate 10.

[0039] Figure 5 shows an example of the installation positions of multiple shape acquisition devices 21 in a plan view. Multiple steel plates 10 stacked on a pallet 53 may not be aligned vertically or horizontally. Therefore, it is desirable to install multiple shape acquisition devices 21 on a crane 50, which is not shown in Figure 5. Each shape acquisition device 21 is installed on a leg structure 52 of the crane 50 that is diagonally opposite to it. Each shape acquisition device 21 scans the area on the near side from its perspective of the multiple steel plates 10 stacked on a pallet 53 installed between the legs of the crane 50. By providing multiple shape acquisition devices 21 in this way, even if the orientation of the multiple steel plates 10 stacked on the pallet 53 is not aligned and the location of the management part 12 does not coincide for each, it becomes possible to acquire the shape data 40 of each symbol 13 more reliably and accurately. At least two shape acquisition devices 21 are sufficient to be installed on the crane 50, but three or more are also acceptable. Furthermore, the shape acquisition devices 21 may be installed on both the lifting device 51 and the leg structure 52.

[0040] It is desirable that the shape acquisition device 21 be installed as close as possible to the steel plate 10. The closer the shape acquisition device 21 is to the multiple steel plates 10 stacked on the pallet 53, the narrower the scanning range of the shape acquisition device 21 becomes. Therefore, this is advantageous in reducing unnecessary data other than the shape data 40 that indicates the symbol 13, and contributes to reducing the computational load and the amount of data to be stored. In addition, the closer the shape acquisition device 21 is to the steel plate 10, the more accurate the shape data 40 can be acquired. In other words, even if the steel plate 10 is thin, such as a thin plate or a medium plate, the shape data 40 that indicates the symbol 13 can be acquired. Places closer to the steel plate 10 include, for example, the lower ends of the lifting devices 51 and leg structures 52.

[0041] The multiple steel plates 10 stacked on the pallet 53 are of varying sizes, and sometimes a larger steel plate 10 may be stacked below the top steel plate 10. In this case, the shape acquisition device 21 will acquire not only the shape data 40 showing the shape of the symbol 13 of the top steel plate 10, but also the shape data 40 showing the shape of the symbol 13 of the larger steel plate 10. Each shape data 40 can be distinguished, for example, by the height from the ground or the pallet 53, but this becomes difficult when the steel plate 10 is thin. Therefore, when the shape acquisition device 21 scans from the center of the pallet 53 outwards in the longitudinal direction of the pallet 53 (when vertical scanning is performed from the center of the pallet 53 outwards), it is sufficient to determine that the first acquired shape data 40 represents the shape of the symbol 13 of the top steel plate 10. Furthermore, when the shape acquisition device 21 scans from the outside of the pallet 53 in the longitudinal direction toward the center of the pallet 53 (when vertical scanning is performed from the outside of the pallet 53 toward the center), it only needs to determine that the last acquired shape data 40 represents the shape of the symbol 13 of the topmost steel plate 10. In this way, by processing the scanning direction of the shape acquisition device 21 and the order of the acquired shape data 40, it is possible to accurately acquire shape data 40 representing the shape of the symbol 13 of the topmost steel plate 10, even if multiple steel plates 10 of different sizes are stacked on the pallet 53. Depending on the management unit 12, the shape acquisition device 21 may also scan from the center of the pallet 53 toward the outside in the short direction of the pallet 53, or vice versa. Furthermore, by comparing the shape data 40 indicating the shape of the symbol 13 formed on the surface of the uppermost steel plate 10 with the respective shape data 40 indicating the shape of the symbol 13 formed on the edges of the multiple steel plates 10, it is also possible to identify the shape data 40 indicating the shape of the symbol 13 on the uppermost steel plate 10.

[0042] The arithmetic unit 22 can be any known computer. The arithmetic unit 22 has a central processing unit (CPU), a main memory unit (memory), an auxiliary storage unit (e.g., HDD), and an input / output unit. When a predetermined program stored in the auxiliary storage unit is started and executed, the arithmetic unit 22 executes each data processing instructed by that program. Specifically, the program is executed when the shape acquisition device 21 acquires shape data 40, and causes the arithmetic unit 22 to execute a procedure to convert the shape data 40 into an identification number N.

[0043] In the procedure for managing the steel plate 10 illustrated in Figure 6, first, shape data 40 is acquired by the shape acquisition device 21 (S110). Next, a predetermined program causes the calculation device 22 to execute each step (S120~S140). Finally, the process ends when the identification number N is determined. The details of each step (S110~S140) are described below.

[0044] In the step of acquiring shape data 40 (S110), the shape acquisition device 21 acquires shape data 40 showing the shape of the symbol 13 formed on the control area 12 of the steel plate 10 located on the top row of the multiple steel plates 10 stacked on the pallet 53. The shape data 40 acquired by the shape acquisition device 21 is stored in the auxiliary storage unit of the calculation unit 22. In addition to the shape data 40 showing the symbol 13 formed on the control area 12 of the steel plate 10 located on the top row, in this step (S110), shape data 40 showing the symbol 13 formed on the control area 12 of steel plates 10 located in lower rows than the steel plate 10 located on the top row may also be acquired. Specifically, for the top-row steel plate 10, shape data 40 showing the symbol 13 formed on both the plate surface and the edge surface of the control area 12 is acquired, and for the lower-row steel plates 10, shape data showing the symbol 13 formed on the edge surface of the control area 12 is acquired.

[0045] In step (S120) of identifying the symbol 13, the arithmetic unit 22 performs data processing to identify the symbol 13 based on the shape data 40. This step (S120) will be explained in detail using the example where the symbol 13 mimics a one-dimensional code and a 3D-LiDAR sensor is used as the shape acquisition device 21. First, the arithmetic unit 22 performs data processing to calculate the width B of each through hole 14 and the width b of each gap 15 based on the shape data 40. Next, the arithmetic unit 22 treats the through holes 14 as spaces in a one-dimensional code and the gaps 15 as bars in a one-dimensional code, generates a one-dimensional barcode, and performs data processing to identify the symbol 13.

[0046] Figure 7 shows a portion of the shape of symbol 13, created from shape data 40. The black dots in Figure 7 indicate the locations where the laser beam emitted from the 3D-LiDAR sensor was reflected. The spacing between adjacent black dots is wider on the left side of Figure 7 compared to the right side, indicating that the shape acquisition device 21 (not shown) is emitting the laser beam from the upper right side of Figure 7. The acquired shape data 40 contains numerous data points for each location where the laser beam was reflected, including the distance from the shape acquisition device 21, the horizontal scanning angle, and the vertical scanning angle. By analyzing this shape data 40, the arrangement and size (width) of each through-hole 14 and gap can be obtained as part of the shape of symbol 13. In Figure 7, the gaps 15 with width b1, through holes 14 with width B1, gaps 15 with width b2, through holes 14 with width B2, gaps 15 with width b3, through holes 14 with width B3, gaps 15 with width b4, through holes 14 with width B4, gaps 15 with width b5, through holes 14 with width B5, and gaps 15 with width b6 are arranged from right to left.

[0047] The calculated widths B and b differ from each other due to factors such as errors. Therefore, it is desirable that the calculation unit 22 classifies the calculated widths B and b based on their respective sizes, calculates representative values ​​for each classified group, and performs data processing in which these calculated representative values ​​are considered to be the widths B and b belonging to their respective groups. Specifically, in Figure 7, the data can be classified into six groups: the group of width B1, the group of width B2, the group of widths B3 to B5, the group of width b1, the group of widths b2 to b4, and the group of widths b5 and b6. The representative values ​​for each group are adopted as the widths B and b belonging to their respective groups. In other words, in Figure 7, a one-dimensional barcode is generated in which, from right to left, the following are arranged in order: a medium-width bar (two narrow bars), a wide space, a narrow bar, a narrow space, a narrow bar, a medium-width space, a wide bar, a medium-width space, and a wide bar.

[0048] In step (S130), which converts symbol 13 to identification number N, the arithmetic unit 22 performs data processing to convert the identified symbol 13, which is a one-dimensional code, into identification number N. In this step (S130), the conversion from the identified one-dimensional code to identification number N is performed in accordance with the barcode symbol system standardized in JIS X0502 to X0508.

[0049] In step S140, which outputs the converted identification number N, data processing is performed so that the identification number N converted by the arithmetic unit 22 is output to the output unit. Note that the output destination for the identification number N may be an arithmetic unit other than the arithmetic unit 22, and that other arithmetic unit may hold the management data 30. By outputting the identification number N to the output unit, the unique identification number N of the steel plate 10 placed on the top layer of the multiple steel plates 10 stacked on the pallet 53 is obtained.

[0050] As described above, according to this embodiment, the symbol 13 directly formed on the excess control portion 12 does not disappear from the steel plate 10 until the product portion 11 and the control portion 12 are separated when the steel plate 10 is processed into a product. Therefore, the unique identification number N of the steel plate 10 can be determined by detecting the symbol 13 until it is processed into a product.

[0051] Furthermore, by identifying the unique identification number N of each steel plate 10, it is possible to use the identified identification number N and the management data 30 to check various information about the steel plate 10 linked to the identification number N. This is advantageous for efficiently managing the large number of steel plates 10 present in steel mills and steel warehouses.

[0052] If the multiple through holes 14 formed in the management area 12 of the steel plate 10 are recessed inward from the edge, the shape acquisition device 21 can acquire shape data 40 representing the shape of the symbols 13 formed on the edge surfaces of the management area 12 of the multiple steel plates 10 stacked on the pallet 53. This makes it possible to determine the unique identification number N of each steel plate 10 other than the top steel plate 10. Conventional technologies such as stamping, stenciling, and labeling cannot determine the identification number N of multiple steel plates 10 at once. On the other hand, according to the above embodiment, it becomes possible to read the symbols 13 of multiple steel plates 10, and by determining the identification number N indicated by each symbol 13, various information about multiple steel plates 10 can be confirmed. In this way, by determining the identification number N of multiple steel plates 10 at once, the effort required to determine a large number of identification numbers N can be greatly reduced, and the time required for management work in steel mills and steel warehouses can be greatly reduced. In addition, when handling multiple steel plates 10 at once using the lifting device 51 of the crane 50, information about each steel plate 10 can be confirmed. This eliminates the need for workers to manually check multiple steel plates 10 being handled by the crane 50. As described above, reading the symbols 13 of each of the multiple steel plates 10 at once is advantageous for more efficient management of the numerous steel plates 10 present in steel mills and steel warehouses.

[0053] Next, we will describe two modified examples of the steel plate 10.

[0054] In Modification 1 illustrated in Figure 8, the symbol 13 is different from that of the embodiment of the steel plate 10 illustrated in Figure 1 described above. Specifically, in Modification 1, the shape of the multiple through holes 14 in symbol 13 is circular in plan view. In Modification 1, symbol 13 is represented solely by the arrangement of the multiple through holes 14. Thus, it is sufficient that symbol 13 is represented by arranging the multiple through holes 14 according to a predetermined rule, and the shape and arrangement of the multiple through holes 14 can be arbitrarily set.

[0055] In Modification 2 illustrated in Figure 9, the position of the control portion 12 is different from that of the embodiment of the steel plate 10 illustrated in Figure 1, due to the difference in the shape of the product portion 11. Specifically, in Modification 2, the control portion 12 is located on a part of the edge of the long side of the steel plate 10 in a plan view. Since the control portion 12 is a surplus portion other than the product portion 11, it may be located in a position other than that illustrated in Modification 2. For example, if the product portion 11 has a gap in the central part of the steel plate 10 in a plan view, the control portion 12 may be located in that gap.

[0056] Although embodiments of the present invention have been described above, the steel plate, its management system, and management method of the present invention are not limited to specific embodiments, and various modifications and changes are possible within the scope of the gist of the present invention.

[0057] The multiple through-holes 14 of symbol 13 are not limited to those that penetrate the control area 12 in a direction perpendicular to the plate surface. The multiple through-holes 14 may also penetrate the control area 12 in a direction intersecting the plate surface of the control area 12. Specifically, the multiple through-holes 14 may penetrate one plate surface of the control area 12 and the edge surface of the control area 12. In this way, having the multiple through-holes 14 penetrate the control area 12 in a direction intersecting the plate surface, excluding the direction perpendicular to the plate surface, is advantageous in suppressing the reduction in strength of the control area 12 due to the formation of multiple through-holes 14. Furthermore, in steel mills and steel warehouses, the front and back sides of the steel plate 10 are not reversed, so if multiple through-holes 14 are formed in one plate surface and the edge surface of the steel plate 10, it is sufficient to identify the identification number N.

[0058] As illustrated in Figure 10, the management system 20 may include, in addition to the multiple shape acquisition devices 21 illustrated in Figure 4, a shape acquisition device 21 positioned lower down from the leg structure 52 of the crane 50. To read the shape of the symbol 13 formed on the edge surface of each of the multiple steel plates 10 stacked on the pallet 53, it is necessary to strike each edge surface with light or electromagnetic waves emitted from the shape acquisition device 21. However, at the position of the shape acquisition device 21 illustrated in Figure 4, the largest steel plate 10 among the multiple steel plates 10 may block the light or electromagnetic waves emitted from the shape acquisition device 21 from that steel plate 10, making it impossible to read the shape of the symbol 13 formed on the edge surface of the steel plates 10 positioned lower than that largest steel plate 10. Therefore, by providing a shape acquisition device 21 positioned lower down, it becomes possible to read the shape of the symbol 13 formed on the edge surface of more steel plates 10.

[0059] Furthermore, even a handheld device that integrates the shape acquisition device 21 and the calculation device 22 can read the shape of the symbols 13 formed on the edges of each of the stacked steel plates 10. [Explanation of Symbols]

[0060] 10 steel plate 11 Product parts 12 Management part 13 Symbols 14 Through holes 15 Gap 20 Management Systems 21 Shape acquisition device 22 Arithmetic unit

Claims

1. A steel plate having a product portion used in the product and a surplus management portion excluding the product portion, and being divided into the product portion and the management portion in a plan view, with a symbol indicating a unique identification number directly formed on the surface of the management portion.

2. The steel plate according to claim 1, wherein the symbol has a plurality of through holes, and the size and position of each of the through holes indicates the identification number.

3. The steel plate according to claim 2, wherein the symbol is modeled after a one-dimensional code indicating the identification number, with each of the through holes aligned in one direction and the gaps between each of the through holes and between adjacent through holes in the same direction.

4. The steel plate according to claim 2 or 3, wherein the control portion is located on the edge, the through hole is recessed inward from the edge surface, and the symbol is displayed on the plate surface and the edge surface.

5. The steel plate according to claim 1, wherein the combined shape of the product portion and the control portion in a plan view forms a rectangle.

6. The steel plate according to claim 1, wherein the product portion and the control portion, which are separate entities, are joined together.

7. In a steel plate management system equipped with a calculation device that grasps the unique identification number of a steel plate, the steel plate is managed according to the grasped identification number, The steel plate is divided in plan view into a product portion used in the product and a management portion which is surplus after removing the product portion, and the symbol indicating the identification number is directly formed on the surface of the management portion. The system is equipped with a shape acquisition device that acquires shape data showing the shape of the aforementioned symbol. A steel plate management system configured such that the calculation device performs data processing to convert the shape data acquired by the shape acquisition device into the identification number.

8. In a method for managing steel plates, in which a calculation device obtains a unique identification number for a steel plate and manages the steel plate using the obtained identification number, The steel plate is divided in plan view into a product portion used in the product and a management portion which is surplus after removing the product portion, and the symbol indicating the identification number is directly formed on the surface of the management portion. Shape data representing the shape of the symbol is acquired using a shape acquisition device. A method for managing steel plates, which involves performing data processing to convert the shape data acquired by the shape acquisition device into the identification number using the calculation device.

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