Crane, conveyance method, and plate member manufacturing method

Abstract

To provide a crane capable of accurately detecting a position of a plate member to be lifted, a conveyance method and a plate member manufacturing method.SOLUTION: A crane 1 for loading and conveying a plate member 2 includes: a holding mechanism 11 that lifts and holds the plate member 2; a drive mechanism 12 that moves the holding mechanism 11 at least in a horizontal direction; an image acquisition mechanism 14 that acquires an image of the plate member 2 so as to include a characteristic portion of the plate member 2; and a control mechanism 15 that detects the characteristic portion from the image, calculates a position and a horizontal rotation angle of the plate member 2 from a position of the characteristic portion, and adjusts a horizontal position of the holding mechanism 11 based on the position and the rotation angle of the plate member.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a crane, a transportation method, and a method for manufacturing a plate member. [Background technology]

[0002] The steelworks' thick plate plant includes a rolling facility that rolls block steel plates (an example of a plate member) to a desired thickness, a finishing facility that cuts the rolled steel plates to shipping size, removes burrs from the edges, cleans surface defects, and inspects for internal defects, and a product warehouse that stores steel plates awaiting shipment. The process of rolling in the rolling facility is called the rolling process, and the process of inspecting in the finishing facility is called the finishing process. Steel plates in process in the finishing facility and steel plates awaiting shipment in the product warehouse are stored in a stack of several to a dozen sheets due to space restrictions. When steel plates are rearranged or shipped, a crane equipped with an electromagnetic lifting magnet (also called a "lift magnet") or the like is used to lift and move one or several target steel plates.

[0003] When carrying out this work, it is necessary to accurately grasp the position of the center of gravity of the steel plate. In particular, when lifting thick steel plates with a thickness of 100 mm or more with a crane that is commonly used in steelworks' thick plate factories, if the center of gravity of the steel plate to be lifted and the center of the lifting magnet are misaligned, there is a risk that the load will be uneven and the steel plate will fall in the worst case. For this reason, a means of accurately grasping the position of the center of gravity of the steel plate is required. To address this issue, for example, Patent Document 1 discloses a method for detecting the position of a steel plate to be lifted. For example, Patent Document 1 proposes a method for obtaining the shape and center of gravity of stacked steel plates by image processing that separates an image captured by a camera from diagonally above the steel plate into a planar image and a side image of the steel plate and extracts each of them. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 7-330287 Summary of the Invention [Problem to be solved by the invention]

[0005] The method in Patent Document 1 detects the step shape of stacked steel plates by image processing, separates them at the step, and calculates the installation position of each steel plate. However, in a situation where multiple thin steel plates with a thickness of about 10 mm or less are stacked, the upper and lower steel plates are detected as if they are one unit, making it difficult to detect only the position of the uppermost steel plate to be lifted. Therefore, the present invention has been made with attention to the above-mentioned problems, and aims to provide a crane, a transportation method, and a method for manufacturing a plate member that can accurately detect the position of the plate member to be lifted. [Means for solving the problem]

[0006] (1) According to one aspect of the present invention, there is provided a crane for loading and transporting plate members, the crane comprising: a holding mechanism for lifting and holding the plate member; a drive mechanism for moving the holding mechanism at least in a horizontal direction; an image capture mechanism for capturing an image of the plate member so that a characteristic portion of the plate member is included; and a control mechanism for detecting the characteristic portion from the image, calculating a position and a horizontal rotation angle of the plate member from the position of the characteristic portion, and adjusting the horizontal position of the holding mechanism based on the position of the plate member and the rotation angle.

[0007] (2) In the crane described in (1) above, the characteristic parts are a marking attached to a predetermined position of the plate member and an end of the plate member, and the control mechanism calculates the rotation angle from the position of the end of the plate member.

[0008] (3) In the crane described in (2) above, when the rotation angle is less than the tilt angle threshold, the control mechanism calculates the position of the center of gravity of the plate member as the position of the plate member from the dimensions of the plate member and the position of the marking. (4) In the crane described in (2) or (3) above, when the rotation angle is equal to or greater than the tilt angle threshold, the control mechanism calculates the position of the center of gravity of the plate member as the position of the plate member from the dimensions of the plate member, the position of the marking, and the rotation angle.

[0009] (5) In a crane described in any one of (2) to (4) above, the control mechanism selects the end of the plate member that is closest to the marking, and calculates the rotation angle from the inclination of the selected end with respect to the movement direction of the holding mechanism. (6) A crane described in any one of (1) to (5) above further includes a self-position detection mechanism for detecting a horizontal center position of the holding mechanism, and the control mechanism issues a drive command to the drive mechanism so that the distance between the center of gravity of the plate member and the center position of the holding mechanism is equal to or less than a threshold value.

[0010] (7) A crane described in any one of (1) to (6) above further includes a running rail provided on the ceiling of a building in which the plate member is stored, and the holding mechanism is moved horizontally by moving the drive mechanism to which the holding mechanism is attached along the running rail. (8) In the crane described in (7) above, the image acquisition mechanism is attached to the drive mechanism.

[0011] (9) According to one aspect of the present invention, there is provided a method for loading and transporting a plate member, comprising the steps of: acquiring an image of the plate member so that a characteristic portion of the plate member is included; detecting the characteristic portion from the image and calculating a position and a horizontal rotation angle of the plate member from the position of the characteristic portion; adjusting the horizontal position of a holding mechanism that hoists and holds the plate member based on the position and the rotation angle of the plate member; and, after adjusting the horizontal position of the holding mechanism, hoisting and transporting the plate member. (10) According to one aspect of the present invention, there is provided a method for manufacturing a plate member, in which, in a manufacturing process for manufacturing the plate member, the plate member is loaded and transported using a crane described in any one of (1) to (8) above. Effect of the Invention

[0012] According to one aspect of the present invention, a crane, a transportation method, and a method for manufacturing a plate member are provided that are capable of accurately detecting the position of a plate member to be lifted. [Brief description of the drawings]

[0013] [Figure 1] FIG. 1 is a schematic diagram showing a crane according to an embodiment of the present invention. [Diagram 2] FIG. 2 is an explanatory diagram showing the relationship between components of a crane. [Diagram 3] FIG. 2 is a configuration diagram of a control mechanism. [Figure 4] FIG. 4 is an explanatory diagram showing the positional relationship between a plate member and markings. [Diagram 5] FIG. 1 is a process flow diagram showing a cargo handling and transportation method. [Figure 6] FIG. 2 is a plan view showing the installation state of a steel plate having a thickness of t20 in Example 1. [Figure 7] FIG. 2 is a plan view showing the installation state of steel plates having thicknesses t5, t10, and t20 in Example 1. [Figure 8] FIG. 11 is a plan view showing the installation state of steel plates having thicknesses t5, t10, and t20 in Example 2. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] In the following detailed description, an embodiment of the present invention will be described with reference to the drawings. In the description of the drawings, identical or similar parts are given identical or similar symbols, and duplicated explanations are omitted. Each drawing is schematic and may differ from the actual one. In addition, the embodiments shown below are examples of devices and methods for embodying the technical idea of ​​the present invention, and the technical idea of ​​the present invention does not specify the materials, structures, arrangements, etc. of the components as described below. The technical idea of ​​the present invention can be modified in various ways within the technical scope defined by the claims described in the claims.

[0015] FIG. 1 shows a schematic diagram of a crane 1 according to an embodiment of the present invention. FIG. 2 shows a schematic diagram showing the relationship between the components of the crane 1. The crane 1 is an overhead crane that hoists and transports a plate member 2. In this embodiment, the plate member 2 is a steel plate, and the crane 1 transports the plate member 2 stored in a building. In addition, a traveling rail 3 along which the crane 1 moves is provided on the ceiling of the building. The traveling rail 3 may be included in the crane 1. The crane 1 includes a holding mechanism 11, a driving mechanism 12, a self-position detection mechanism 13, an image acquisition mechanism 14, and a control mechanism 15.

[0016] The holding mechanism 11 is a mechanism that lifts the plate member 2, which is the object to be lifted, in response to a lifting command f from the control mechanism 15, and in this embodiment is an electromagnet type lifting magnet as an example. The holding mechanism 11 is preferably an electromagnet type lifting magnet, but may be a permanent magnet type lifting magnet, a clamp, or the like.

[0017] The driving mechanism 12 is a mechanism for moving the holding mechanism 11 in response to a driving command e from the control mechanism 15, and in this embodiment, includes a traveling platform 121, a crane girder 122, and a hoist 123. The crane girder 122 is attached to the traveling rail 3 via the traveling platform 121. That is, the crane 1 is configured to be movable in a single axis direction (x-axis direction) parallel to the horizontal direction by the driving mechanism 12 moving along the traveling rail 3. The hoist 123 is configured to be movable on the crane girder 122 in a single axis direction (y-axis direction) parallel to the horizontal direction and perpendicular to the moving direction of the crane 1. The holding mechanism 11 is suspended and fixed to the crane girder 122 via the hoist 123. The hoist 123 can move the holding mechanism 11 in the vertical direction by winding up or down the holding mechanism 11.

[0018] The self-position detection mechanism 13 is a mechanism for detecting the planar position coordinates (horizontal position) of the drive mechanism 12, and is, for example, a laser range finder. In the example shown in FIG. 1, the self-position detection mechanism 13 is a laser range finder installed on the crane girder 122, and detects the planar position of the drive mechanism 12, for example, by measuring the distance to the wall surfaces in two directions. The self-position detection mechanism 13 may be any mechanism capable of detecting the position of the drive mechanism 12, such as an outdoor GPS, an indoor GPS, a beacon, or the like, and may be installed on a place other than the crane girder 122, such as the ground. The planar position coordinates of the drive mechanism 12 acquired by the self-position detection mechanism 13 are also referred to as the drive mechanism position a, and this drive mechanism position a is sent to the control mechanism 15.

[0019] The image acquisition mechanism 14 is a camera or the like installed on the crane girder 122, and captures an image of the ground from above in the vertical direction. The image acquisition mechanism 14 captures an image of the plate member 2 so that the characteristic parts of the plate member 2 are included. The image acquisition mechanism 14 is preferably a camera that captures still images, but may also be a video camera that records moving images, an infrared camera, or the like. In addition, it is preferable that the image acquisition mechanism 14 is capable of acquiring an image with a high resolution enough to identify the characteristic parts of the plate member 2 placed on the ground. In this embodiment, the characteristic parts of the plate member 2 are markings such as a product number attached to a predetermined position of the plate member 2 and the end of the plate member 2. For example, the image acquisition mechanism 14 may be a camera (4K camera) that can acquire an image with a resolution of 4K size. Furthermore, the image acquisition mechanism 14 may be installed in a place other than the crane girder 122, such as the ground. The image acquired by the image acquisition mechanism 14 is also called a transport object image c, and this transport object image c is sent to the control mechanism 15.

[0020] The control mechanism 15 is a mechanism that adjusts the position of the holding mechanism 11 by controlling the drive mechanism 12. The control mechanism 15 is preferably a PLC (Programmable Logic Controller), but may be a PC or the like. The control mechanism 15 determines the drive amount of the crane 1 based on the drive mechanism position a acquired by the self-position detection mechanism 13 and the transport object image c acquired by the image acquisition mechanism 14, and controls the drive mechanism 12 and the holding mechanism 11 to hoist the plate member 2. The control mechanism 15 may be installed on the crane girder 122, or may be installed elsewhere than the crane girder 122, such as on the ground.

[0021] Specifically, as shown in Fig. 2, the control mechanism 15 acquires a drive mechanism position a and a transport object image c from the self-position detection mechanism 13 and the image acquisition mechanism 14, respectively, and outputs a drive command e and a lifting command f to the drive mechanism 12 and the holding mechanism 11, respectively. As shown in Fig. 3, the control mechanism 15 has a center position calculation unit 151, an information recording unit 152, a center of gravity position calculation unit 153, and a drive amount calculation unit 154.

[0022] The center position calculation unit 151 calculates the center position (holding mechanism center position b) of the holding mechanism 11 from the drive mechanism position a. The calculated holding mechanism center position b is sent to the drive amount calculation unit 154. The holding mechanism center position b is expressed as coordinates (x c ,y c )

[0023] The information recording unit 152 records at least the dimensions (s, t) and the marking attachment position (u, v) of the plate member 2 as information on the plate member 2. The dimensions (s, t) are the length and width of the plate member 2 such as a steel plate, for example, the length s and the length t of the plate member 2 shown in FIG. 4. The marking is a product number or the like attached to the plate member 2. When the plate member 2 is a steel plate, a product number or the like is printed as a marking at a predetermined position (corner) on the surface of the steel plate using a stencil and a spray material. The printing position of the product number or the like is determined, for example, by the thick steel plate marking standard (JSSKX-71-0000 (2020)). The marking attachment position (u, v) is the attachment position of the marking attached to the plate member 2, for example, the length u and the length v of the plate member 2 shown in FIG. 4. The length u is the distance from the left end of the plate member 2 to the marking in FIG. 4, and the length v is the distance from the lower end of the plate member 2 to the marking in FIG.

[0024] The center of gravity position calculation unit 153 calculates the position of the marking (marking position) and the position of the end of the plate member 2 (end position) from the transported object image c. The center of gravity position calculation unit 153 also calculates the transported object center of gravity position d, which is the center of gravity position of the plate member 2, which is the transported object, from the dimensions (s, t) and marking attachment positions (u, v) acquired from the information recording unit 152, the marking position, and the end position. The marking position and the transported object center of gravity position d are expressed as coordinates (x m ,y m ) and coordinates (x g ,y g) The end position is set as a horizontal rotation angle θ with respect to the x-axis direction or the y-axis direction (the moving direction of the holding mechanism 11). Details of the method for calculating the marking position, the end position, and the center of gravity position d of the transported object will be described later.

[0025] The drive amount calculation unit 154 calculates the drive amount of the crane 1, that is, the drive command e and the lifting command f, using the holding mechanism center position b and the transport object center of gravity position d acquired respectively from the center position calculation unit 151 and the center of gravity position calculation unit 153. The method of calculating the drive amount will be described later in detail.

[0026] (Handling and transporting method and manufacturing method of plate members) The method for loading and transporting a plate member 2 according to this embodiment is performed according to the process flow of automatic travel shown in Fig. 5. In the process shown in Fig. 5, a crane 1 automatically travels and lifts up a plate member 2 stored in a building. The plate member 2 is placed at a predetermined storage position in the building. The plate member 2 to be transported may also be stacked with other plate members 2, in which case the plate member 2 to be transported is placed at the top of the multiple stacked plate members 2. Multiple storage positions are set in the building, and each storage position is configured to be able to store a single plate member 2 or multiple stacked plate members 2.

[0027] First, the crane 1 moves to the vicinity of the plate member 2 that is the object to be transported (S100). In step S100, the crane 1 moves to a distance where the plate member 2 can be photographed by the image acquisition mechanism 14. At this time, it is preferable to perform the movement using position information of the section in which the plate member 2 is installed (for example, a pile of steel plates if the plate member 2 is a steel plate), but the movement may also be performed by providing position information by other means.

[0028] Next, the self-position detection mechanism 13 detects the drive mechanism position a (S102). The detected drive mechanism position a is sent to the center position calculation unit 151. Furthermore, the center position calculation unit 151 calculates the holding mechanism center position b, which is the center position of the holding mechanism 11 in the planar coordinates, from the acquired driving mechanism position a (S104). There is no particular limitation on the method of calculating the holding mechanism center position b using the driving mechanism position a. For example, if the relative planar position of the holding mechanism center position b with respect to the driving mechanism position a is determined in advance, the holding mechanism center position b may be calculated by correcting the driving mechanism position a according to this relative planar position.

[0029] Thereafter, the image acquisition mechanism 14 acquires a transported object image c by taking an image including the plate member 2 of the transported object (S106). The transported object image c need only include the markings on the plate member 2 of the transported object and the characteristic parts of the end of the plate member 2, and does not necessarily need to include the entire plate member 2 of the transported object. Here, the end of the plate member 2 as the characteristic part is preferably the end closest to the marking on the plate member 2 (the left end or the bottom end of the plate member 2 in the example shown in FIG. 4).

[0030] Next, the center of gravity position calculation unit 153 calculates the marking position (x m ,y m ) and obtains the horizontal rotation angle θ of the plate member 2 from the inclination of the end of the plate member 2 (S108). At this time, the center of gravity position calculation unit 153 detects the marking and end information of the plate member 2 of the transport object from the transport object image c obtained by image analysis or the like, thereby calculating the marking position (x m ,y m ) and the rotation angle θ.

[0031] (Get marking position) Based on the relative positional relationship between the image capturing position of the image capturing mechanism 14 and the driving mechanism 12 or the holding mechanism 11 that is set in advance, the position coordinates of the lower left end of the marking captured using the driving mechanism position a or the holding mechanism center position b (marking position (x m ,y m)) can be obtained. The method of detecting the marking is preferably to prepare training data in advance from an image of the marking using R-CNN, and to perform object detection using the training data. Training data may also be created using CNN, YOLO, etc.

[0032] (Getting the rotation angle) In obtaining the rotation angle, an image of the end of the plate member 2 is binarized, and the points where the gradient of brightness is equal to or greater than a predetermined value are detected as straight lines, and from among the detected straight lines, the one that is the shortest distance from the position coordinate of the lower left end of the marking is selected. Then, the angle that the selected straight line makes with the x-axis or y-axis in the horizontal direction can be obtained as the rotation angle θ. Note that as a method of detecting the end of the plate member 2, learning data may be created using R-CNN, CNN, YOLO, or the like, and object detection may be performed.

[0033] After step S108, the center of gravity position calculation unit 153 determines whether the rotation angle θ of the plate member 2 is less than the tilt angle threshold (S110). The tilt angle threshold is appropriately set based on the amount of deviation of the center of gravity position of the plate member 2 due to the tilt of the plate member 2, and is preferably about 1°. If the rotation angle θ is within a range of less than 1°, there is almost no deviation of the center of gravity position, and the plate member 2 can be stably lifted.

[0034] If it is determined in step S110 that the rotation angle θ is less than the tilt angle threshold, the center of gravity position calculation unit 153 calculates the marking position (x m ,y m ) based on the center of gravity position d(x g ,y g In step S112, the marking position (x m ,y m ) and the dimensions (s, t) of the plate member 2 of the transport object and the marking attachment positions (u, v) recorded in the information recording unit 152, the center of gravity position d(x g ,y g The center of gravity position can be calculated using the following formulas (1) and (2).

[0035]

number

[0036] On the other hand, if it is determined in step S110 that the rotation angle θ of the plate member 2 is equal to or greater than the inclination angle threshold, the center of gravity position calculation unit 153 calculates the marking position (x m ,y m ) and the rotation angle θ, the center of gravity position d(x g ,y g ) is calculated (S114). m ,y m ), the rotation angle θ, and the dimensions (s, t) and marking attachment positions (u, v) of the plate member 2 of the transport object recorded in the information recording unit 152 are used to determine the center of gravity d(x g ,y g The center of gravity position can be calculated using the following formulas (3) and (4).

[0037]

number

[0038] After step S112 or step S114, the drive amount calculation unit 154 determines whether the horizontal distance D between the holding mechanism center position b and the transport object center position d is equal to or less than a threshold value (S116). The distance D may be the horizontal linear distance between the holding mechanism center position b and the transport object center position d, or may be the distance in the x-axis direction and the y-axis direction between the holding mechanism center position b and the transport object center position d. The threshold value depends on the dimensions of the plate member 2 of the transport object, but is preferably about 50 mm. If the distance D is within a range of 50 mm, the plate member 2 can be stably lifted.

[0039] If it is determined in step S116 that the horizontal distance D between the holding mechanism center position b and the transport object center of gravity position d is greater than the threshold value, the drive amount calculation unit 154 determines that the position of the crane 1 needs to be adjusted, calculates the drive amount, and issues a drive command e to the drive mechanism 12 (S118). At this time, the drive amount calculation unit 154 calculates the movement amount for moving the holding mechanism center position b to the transport object center of gravity position d. Then, it issues a drive command e so that the holding mechanism 11 moves by this movement amount. The drive mechanism 12 receives the drive command e and moves the holding mechanism 11. After step S118, the processes from step S102 onwards are performed again.

[0040] On the other hand, if it is determined in step S116 that the horizontal distance D between the holding mechanism center position b and the transport object center of gravity position d is equal to or less than the threshold value, the drive amount calculation unit 154 determines that the position adjustment of the crane 1 is complete, and issues a lifting command f to the holding mechanism 11 (S120). The holding mechanism 11 receives the lifting command f and lifts the plate member 2.

[0041] Then, when step S120 ends, the lifting process of the plate member 2 shown in Fig. 5 is completed. After the lifting process of the plate member 2 shown in Fig. 5, the crane 1 transports the lifted plate member 2 to any location. In addition, in the manufacturing method of the plate member 2 according to this embodiment, in the manufacturing process of the plate member 2, the loading and transporting method according to this embodiment is used to load and transport the plate member 2.

[0042] According to the crane 1, the method for handling and transporting, and the method for manufacturing a plate member of the present embodiment, when the plate member 2 such as a steel plate is lifted by the crane 1, the position of the plate member 2 to be lifted can be accurately detected by reading characteristic parts such as markings on the plate member 2. In particular, with a crane using conventional image recognition technology, it was difficult to detect the topmost plate member from a stack of thin plate members, but according to the present embodiment, the position of the topmost plate member 2 can be detected regardless of the plate thickness. Therefore, the transportation work of the plate member 2 can be made labor-saving and efficient. In addition, by taking into account the rotation angle θ of the plate member 2, the position of the center of gravity can be detected with high accuracy even if the plate member 2 is installed tilted in the horizontal direction.

[0043] <Modification> Although the present invention has been described above with reference to specific embodiments, it is not intended that the invention be limited by these descriptions. By referring to the description of the present invention, other embodiments of the present invention including various modifications in addition to the disclosed embodiments will be apparent to those skilled in the art. Therefore, it should be understood that the embodiments of the invention described in the claims also include embodiments including these modifications described herein, either alone or in combination.

[0044] For example, in the above embodiment, the crane 1 is an overhead crane, but the present invention is not limited to this example. For example, the crane 1 is preferably an overhead crane that is attached to a ceiling, but may be a jib crane, a gantry crane, or the like. The crane 1 may also be capable of simultaneously lifting a plurality of stacked plate members 2. In this case, the crane 1 may use the markings on the uppermost plate member 2 to perform lifting in the same manner as in the above embodiment.

[0045] Furthermore, in the above embodiment, the characteristic part of the plate member 2 is a marking such as a product number, but the present invention is not limited to such an example. The characteristic part of the plate member 2 may be any other marking that is attached to a specific position on the plate member 2 and is identifiable from the transport object image c. For example, the characteristic part of the plate member 2 may be a mark printed for automatic transport by the crane 1, or a QR code (registered trademark) or the like attached with a sticker. When a QR code is used, it is also possible to read information (dimensions, etc.) of the plate member 2 stored in the QR code. In addition, other characteristic parts such as a pattern on the surface of a steel plate may be used. In addition, when the plate member 2 is a steel plate, it is preferable to use a marking of a manufacturing number whose printing position is known as the characteristic part, considering the effort required for attaching a new marking. Furthermore, in the above embodiment, the plate member 2 is a steel plate, but the present invention is not limited to this example. The plate member 2 may be made of other materials and have other dimensions and shapes as long as it is a plate-like member that can be hoisted and transported using a crane. EXAMPLES

[0046] The following tests were carried out as examples to evaluate the controllability of the number of pieces suspended according to the present invention. In Example 1, the crane 1 was moved according to the following procedures [1] to [9], and the central position b of the holding mechanism of the crane 1 after the movement was completed was measured and verified.

[0047] [1] 50 images of a marking on a steel plate, which is the plate component 2, taken from a distance of 1 m are prepared, and these are used to create learning data for marking detection using the R-CNN method. [2] Prepare steel plates with a width of 1,400 mm, height of 2,100 mm, and thickness of 20 mm, and place three of them stacked together without tilting them in the position shown in Figure 6. [3] A marking measuring 600 mm wide x 300 mm high (with the product number or other information written in numbers and letters) is placed using a stencil and spray material so that the bottom left corner of the marking is positioned at (600,400), as shown in Figure 6. [4] A 4K camera with approximately 10 million pixels (3648 x 2736) and a laser range finder are attached to crane 1, an overhead crane that travels 10 m above the steel plate, and the initial position of crane 1 is adjusted so that the image acquisition mechanism 14 is directly above the origin shown in Figure 6. Here, the 4K camera corresponds to the image acquisition mechanism 14, and the laser range finder corresponds to the self-position detection mechanism 13. [5] The marking position is detected from the image captured by the image capture mechanism 14 using the learning data, and the horizontal rotation angle of the steel plate is detected from the edge position of the steel plate in the image. [6] Since the detected rotation angle is less than the inclination angle threshold (1°), the position of the center of gravity of the uppermost steel plate to be transported is calculated based on the detected marking position, the steel plate dimensions and the marking attachment position stored in the information recording unit 152. [7] The crane is moved laterally only from (the center of gravity of the uppermost steel plate being transported) to (the center position of the holding mechanism 11 attached to the crane 1). [8] Measure the center position of the holding mechanism 11 attached to the crane 1 using a laser rangefinder, and repeat [6] and [7] until the difference between (the center of gravity of the top steel plate being transported) and (the center position of the holding mechanism 11 attached to the crane 1) is within ±20 mm. [9] Once this is completed, the center position of the holding mechanism 11 attached to the crane 1 is measured using a total station.

[0048] The results of the embodiment are shown in Table 1. It was possible to move the center position of the holding mechanism 11 almost accurately to the target position, which was the center of gravity of the uppermost steel plate to be transported. Furthermore, as shown in Fig. 7, the thickness of the three steel plates to be placed was changed from top to bottom to t5, t10, and t20, and the results are shown in Table 2. Even under these conditions, almost the same results were obtained, and it is clear that the position of the center of gravity can be detected even with thin steel plates with a thickness of 10 mm or less, and that they can be used as targets for lifting by an automatic transport crane.

[0049] [Table 1]

[0050] [Table 2]

[0051] Furthermore, as a comparative example, a verification was also conducted when a ceiling crane was moved to hoist the plate member 2 using a conventional method. In the comparative example, a photograph was taken at an angle of 45° (from a position 7 m above and 7 m away in the y-axis direction) with the same 4K camera as in the example, and the position of the center of gravity of the transported object of the uppermost steel plate was calculated by a method of detecting the steel plate ends by image processing, and the crane was moved traversely based on that information. Table 3 shows the results for a comparative example where three steel plates with a thickness of t20 were stacked as shown in Fig. 6. Under these conditions, each steel plate could be cut and detected, and it was confirmed that the center position of the holding mechanism was moved almost accurately to the target position, which was the center of gravity of the uppermost steel plate to be transported.

[0052] [Table 3]

[0053] On the other hand, in the comparative example, the results of the conditions in which the thickness of the steel plate was changed from top to bottom as shown in Figure 7 are shown in Table 4. Under these conditions, the t5 and t10 steel plates could not be separated as separate steel plates, and were detected as one piece. As a result, a value shifted by about 100 mm in the x direction and about 200 mm in the y direction was detected as the center of gravity of the transported object, and the center position of the holding mechanism was shifted from the target position accordingly. This shows that with this method, the center of gravity of thin steel plates with a thickness of 10 mm or less cannot be accurately detected, and therefore they cannot be used as objects to be lifted by automatic transport cranes.

[0054] [Table 4] EXAMPLES

[0055] Furthermore, as Example 2, a verification similar to that of Example 1 was performed under the condition that the steel plates were installed in an inclined state. As shown in Fig. 8, the verification results in which three steel plates with thicknesses of t5, t10, and t20 were installed at an inclination of 5° are shown in Table 5. In this case, since the detected rotation angle in the above step [6] is equal to or greater than the inclination angle threshold value (1°), the position of the center of gravity of the transported object of the uppermost steel plate is calculated based on the detected marking position, the rotation angle θ, the steel plate dimensions, and the marking attachment position.

[0056] [Table 5]

[0057] As shown in Table 5, even under these conditions, the center position of the holding mechanism 11 could be moved almost accurately to the target position, which was the center of gravity of the uppermost steel plate to be transported. In other words, it is clear that even if the steel plate is placed tilted horizontally, the position of the center of gravity can be detected and it can be used as a lifting target for an automatic transport crane.

[0058] On the other hand, as a comparative example, a verification was also conducted when the overhead crane was moved to hoist the steel plate using the conventional method under the steel plate installation conditions shown in Figure 8. The results are shown in Table 6. Under these conditions, the t5 and t10 steel plates could not be separated as separate steel plates, and were detected as one piece. As a result, a value shifted by approximately 140 mm in the x direction and approximately 150 mm in the y direction was detected as the center of gravity of the transported object, and it was found that the object could not be lifted by the automatic transport crane.

[0059] [Table 6] [Explanation of symbols]

[0060] 1. Crane 11 Retention mechanism 12 Drive mechanism 121 Traveling platform 122 Crane girder 123 Windlass 13 Self-location detection mechanism 14 Image acquisition mechanism 15 Control Mechanism 151 Center position calculation section 152 Information Recording Section 153 Center of gravity position calculation section 154 Drive amount calculation unit 2 Plate members 3 Running rail a Drive mechanism position b Holding mechanism center position c) Image of transported object d Center of gravity of transported object e Drive command

Claims

1. A crane for handling and transporting plate members, a holding mechanism that suspends and holds the plate member; a drive mechanism for moving the holding mechanism at least in a horizontal direction; an image capturing mechanism for capturing an image of the plate member so as to include a characteristic portion of the plate member; a control mechanism that detects the characteristic portion from the image, calculates a position and a horizontal rotation angle of the plate member from a position of the characteristic portion, and adjusts a horizontal position of the holding mechanism based on the position and the rotation angle of the plate member; A crane equipped with

2. the characteristic portion is a marking provided at a predetermined position of the plate member and an end portion of the plate member, The control mechanism calculates the rotation angle from a position of an end of the plate member. The crane of claim 1.

3. the control mechanism calculates a center of gravity position of the plate member as a position of the plate member from a dimension of the plate member and a position of the marking when the rotation angle is less than a tilt angle threshold value; The crane of claim 2.

4. 3. The crane according to claim 2, wherein the control mechanism calculates the position of the center of gravity of the plate member as the position of the plate member from the dimensions of the plate member, the positions of the markings, and the rotation angle when the rotation angle is equal to or greater than a tilt angle threshold value.

5. The crane according to any one of claims 2 to 4, wherein the control mechanism selects an end of the plate member closest to the marking, and calculates the rotation angle from an inclination of the selected end with respect to a movement direction of the holding mechanism.

6. a self-position detection mechanism for detecting a center position of the holding mechanism in a horizontal direction, the control mechanism issues a drive command to the drive mechanism so that a distance between a center of gravity of the plate member and a center position of the holding mechanism becomes equal to or smaller than a threshold value. A crane according to any one of claims 1 to 4.

7. The plate member further includes a running rail provided on a ceiling of a building in which the plate member is stored, The drive mechanism to which the holding mechanism is attached is moved along the traveling rail, thereby moving the holding mechanism in a horizontal direction. A crane according to any one of claims 1 to 4.

8. The crane of claim 7 , wherein the image capture mechanism is attached to the drive mechanism.

9. A method for handling and transporting plate members, comprising: acquiring an image of the plate member including a characteristic portion of the plate member; detecting the characteristic portion from the image, and calculating a position and a horizontal rotation angle of the plate member from a position of the characteristic portion; adjusting a horizontal position of a holding mechanism that suspends and holds the plate member based on the position of the plate member and the rotation angle; a step of adjusting a horizontal position of the holding mechanism and then lifting and transporting the plate member; A transportation method comprising:

10. A method for manufacturing a plate member, comprising the steps of: carrying out loading and transporting the plate member using a crane according to any one of claims 1 to 4 in a manufacturing process for manufacturing the plate member.

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