Crane, transport method, and method for manufacturing plate members

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 transport method, and a method for manufacturing a plate member. [Background technology]

[0002] A steel mill's plate mill is equipped with rolling equipment that rolls block steel plates (an example of plate components) to the desired thickness, finishing equipment that cuts the rolled steel plates to the shipping size, deburrs the edges, cleans up surface defects, and inspects for internal defects, and a product warehouse for storing steel plates awaiting shipment. The rolling process performed in the rolling equipment is called the rolling process, and the inspection process performed in the finishing equipment is called the finishing process. Due to space constraints, steel plates in work-in-progress in the finishing equipment and steel plates awaiting shipment in the product warehouse are stored stacked in piles of several to a dozen or so. When rearranging or shipping steel plates, a crane equipped with, for example, an electromagnet-type lifting magnet (also called a "lifting magnet") is used to lift and move one to several steel plates at a time.

[0003] When performing this task, it is necessary to accurately determine the center of gravity of the steel plate. In particular, when lifting thick steel plates with a thickness of 100 mm or more using cranes commonly used in heavy plate factories of steel mills, if the center of gravity of the steel plate being lifted is misaligned with the center of the lifting magnet, the load will be unevenly distributed, and in the worst case, there is a risk of the steel plate falling. Therefore, a means of accurately determining the center of gravity of the steel plate is necessary. To address these challenges, 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 them separately. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 7-330287 [Overview of the project] [Problems that the invention aims to solve]

[0005] The method described in Patent Document 1 involves detecting the stepped shape of stacked steel plates using image processing, separating them at the stepped sections, and calculating the installation position of each individual steel plate. However, in situations where multiple thin steel plates with a thickness of 10 mm or less are stacked, the upper and lower steel plates are detected as a single unit, making it difficult to detect only the position of the uppermost steel plate that is to be lifted. Therefore, the present invention has been made in view of the above-mentioned problems, and aims to provide a crane, a transport method, and a method for manufacturing a plate member that can accurately detect the position of a plate member to be lifted. [Means for solving the problem]

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

[0007] (2) In the crane described in (1) above, the characteristic part is the marking attached to a predetermined position on the plate member and the 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, the control mechanism calculates the position of the plate member as the center of gravity of the plate member from the dimensions of the plate member and the position of the marking when the rotation angle is less than the tilt angle threshold. (4) In the crane described in (2) or (3) above, the control mechanism calculates the position of the plate member as the center of gravity of the plate member from the dimensions of the plate member, the position of the marking, and the rotation angle when the rotation angle is greater than or equal to the tilt angle threshold.

[0009] (5) In the 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 direction of movement of the holding mechanism. (6) In the crane described in any one of (1) to (5) above, a self-position detection mechanism is further provided for detecting the horizontal center position of the holding mechanism, and the control mechanism gives a drive command to the drive mechanism such that the distance between the center of gravity of the plate member and the center position of the holding mechanism is less than or equal to a threshold.

[0010] (7) In the crane described in any one of (1) to (6) above, the crane is further provided with a running rail installed on the ceiling of the building where 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, a transport method for handling and transporting a plate member is provided, comprising the steps of: acquiring an image of the plate member such that a characteristic portion of the plate member is included; detecting the characteristic portion from the image and calculating the position of the plate member and the horizontal rotation angle from the position of the characteristic portion; adjusting the horizontal position of a holding mechanism for lifting and holding the plate member based on the position of the plate member and the rotation angle; and lifting and transporting the plate member after adjusting the horizontal position of the holding mechanism. (10) According to one aspect of the present invention, in the manufacturing process of manufacturing the above plate member, a method for manufacturing a plate member is provided, in which the above plate member is carried and transported using the crane according to any one of the above (1) to (8).

Effects 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 that can accurately detect the position of a plate member to be lifted are provided.

Brief Description of the Drawings

[0013] [Figure 1] It is a schematic diagram showing a crane according to an embodiment of the present invention. [Figure 2] It is an explanatory diagram showing the relationship between the components of the crane. [Figure 3] It is a configuration diagram of a control mechanism. [Figure 4] It is an explanatory diagram showing the positional relationship between the plate member and the marking. [Figure 5] It is a processing flowchart showing a cargo handling and transportation method. [Figure 6] It is a plan view showing the installation state of a steel plate with a plate thickness t20 in Example 1. [Figure 7] It is a plan view showing the installation state of steel plates with plate thicknesses t5, t10, and t20 in Example 1. [Figure 8] It is a plan view showing the installation state of steel plates with plate thicknesses t5, t10, and t20 in Example 2.

Modes for Carrying Out the Invention

[0014] The following detailed description will illustrate embodiments of the present invention with reference to the drawings. In the drawings, identical or similar parts are denoted by the same or similar reference numerals, and redundant descriptions are omitted. Each drawing is schematic and may differ from reality. Furthermore, the embodiments shown below are illustrative of apparatus and methods for realizing the technical idea of ​​the present invention, and the technical idea of ​​the present invention is not limited to the materials, structure, arrangement, etc., of the components 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 patent claims.

[0015] Figure 1 schematically shows a crane 1 according to one embodiment of the present invention. Figure 2 shows a schematic diagram illustrating the relationships between the components of the crane 1. The crane 1 is an overhead crane that lifts and transports plate members 2. In this embodiment, the plate members 2 are steel plates, and the crane 1 transports the plate members 2 stored in a building. The building also has a travel rail 3 on the ceiling on which the crane 1 moves. Note that the travel rail 3 may also be included in the crane 1. The crane 1 comprises a holding mechanism 11, a drive 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 to be lifted in response to a lifting command f from the control mechanism 15, and in this embodiment, it is an electromagnet-type lifting magnet as an example. The holding mechanism 11 is preferably an electromagnet-type lifting magnet, but it may also be a permanent magnet-type lifting magnet or a clamp, etc.

[0017] The drive mechanism 12 is a mechanism that moves the holding mechanism 11 in response to a drive command e from the control mechanism 15, and in this embodiment, it has a traveling frame 121, a crane girder 122, and a hoisting machine 123. The crane girder 122 is attached to the traveling rail 3 via the traveling frame 121. In other words, the crane 1 is configured to be movable in a uniaxial direction (x-axis direction) parallel to the horizontal direction as the drive mechanism 12 moves along the traveling rail 3. The hoisting machine 123 is configured to be movable on the crane girder 122 in a uniaxial direction (y-axis direction) parallel to the horizontal direction and perpendicular to the direction of movement of the crane 1. The holding mechanism 11 is suspended and fixed to the crane girder 122 via the hoisting machine 123. The hoisting machine 123 can move the holding mechanism 11 in the vertical direction by hoisting or lowering the holding mechanism 11.

[0018] The self-position detection mechanism 13 is a mechanism that detects the planar position coordinates (horizontal position) of the drive mechanism 12, and is, for example, a laser rangefinder. In the example shown in Figure 1, the self-position detection mechanism 13 is a laser rangefinder installed on the crane girder 122, and detects the planar position of the drive mechanism 12 by, for example, measuring the distance to two wall surfaces. The self-position detection mechanism 13 can be any device that can detect the position of the drive mechanism 12, and may be other devices such as an outdoor GPS, indoor GPS, or beacon, and may be installed on the ground or elsewhere other than the crane girder 122. The planar position coordinates of the drive mechanism 12 obtained by the self-position detection mechanism 13 are also called 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 it takes images of the ground from above in a vertical direction. The image acquisition mechanism 14 acquires an image of the plate member 2 such that characteristic parts of the plate member 2 are included. The image acquisition mechanism 14 is preferably a camera that takes still images, but it may also be a video camera that records moving images, an infrared camera, etc. Furthermore, it is preferable that the image acquisition mechanism 14 is capable of acquiring an image with a resolution high enough to identify 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 product numbers attached to predetermined positions on the plate member 2 and the ends of the plate member 2. For example, the image acquisition mechanism 14 may be a camera (4K camera) capable of acquiring images 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 on the ground. The image acquired by the image acquisition mechanism 14 is also called the transported object image c, and this transported 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 also be a PC or the like. The control mechanism 15 also determines the amount of drive for 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 lifts the plate member 2 by controlling the drive mechanism 12 and the holding mechanism 11. The control mechanism 15 may be installed on the crane girder 122, or it may be installed elsewhere, such as on the ground.

[0021] Specifically, as shown in Figure 2, the control mechanism 15 acquires the drive mechanism position a and the transported 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 Figure 3, the control mechanism 15 includes 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 of the holding mechanism 11 (holding mechanism center position b) 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 calculated using coordinates (x) in the x-axis and y-axis directions, which are parallel to each other in the horizontal direction and perpendicular to each other. c ,y c It will be set as follows.

[0023] The information recording unit 152 records at least the dimensions (s,t) and marking mounting positions (u,v) of the plate member 2 as information about the plate member 2. The dimensions (s,t) are the length and width of the plate member 2, such as a steel plate, and are, for example, the lengths s and t of the plate member 2 shown in Figure 4. The marking is the product number or the like attached to the plate member 2. If the plate member 2 is a steel plate, the 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 spray material. The printing position of the product number, etc. is determined, for example, by the Thick Steel Plate Marking Standard (JSSKX-71-0000(2020)). The marking mounting positions (u,v) are the mounting positions of the marking attached to the plate member 2, and are, for example, the lengths u and v of the plate member 2 shown in Figure 4. Length u is the distance from the left end of the marking plate member 2 in Figure 4, and length v is the distance from the bottom end of the marking plate member 2 in Figure 4.

[0024] The center of gravity 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 transport object image c. Furthermore, the center of gravity calculation unit 153 calculates the center of gravity position d of the transport object, which is the center of gravity position of the plate member 2, from the dimensions (s,t) and marking mounting position (u,v) obtained from the information recording unit 152, along with the marking position and end position. The marking position and the center of gravity position d of the transport object are calculated using coordinates (x, y) in the x-axis and y-axis directions. m ,y m ) and coordinates (x g ,y gThese are set respectively. The end position is set as the horizontal rotation angle θ with respect to the x-axis or y-axis (the direction of movement of the holding mechanism 11). Details of how to calculate the marking position, 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, i.e., the drive command e and the lifting command f, using the holding mechanism center position b and the transport object center position d obtained from the center position calculation unit 151 and the center of gravity position calculation unit 153, respectively. Details of the drive amount calculation method will be described later.

[0026] (Methods for handling and transporting materials and methods for manufacturing plate members) The method for handling and transporting the plate members 2 according to this embodiment is carried out according to the automated driving process flow shown in Figure 5. In the process shown in Figure 5, the crane 1 automatically drives and lifts the plate members 2 stored in the building. The plate members 2 are placed in designated storage locations within the building. The plate members 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 on top of the stacked plate members 2. Multiple storage locations are set up within the building, and each storage location is configured to store one or multiple stacked plate members 2.

[0027] First, the crane 1 moves to the vicinity of the plate member 2 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 move using the position information of the area where 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 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 in the plane coordinates of the holding mechanism 11, from the driving mechanism position a to be acquired (S104). The method for calculating the holding mechanism center position b using the driving mechanism position a is not particularly limited. For example, if the relative planar position of the holding mechanism center position b with respect to the driving mechanism position a is predetermined, the holding mechanism center position b may be calculated by correcting the driving mechanism position a according to this relative planar position.

[0029] After that, 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 only needs to include the marking of the plate member 2 of the transported object and the characteristic part at the end of the plate member 2, and does not necessarily need to include all of the 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 lower end of the plate member 2 in the example shown in FIG. 4).

[0030] Next, the centroid position calculation unit 153 acquires the marking position (x m , y m ), which is the position coordinates of the lower left end of the marking, from the acquired transported object image c, and acquires the rotation angle θ in the horizontal direction of the plate member 2 from the inclination of the end of the plate member 2 (S108). At this time, the centroid position calculation unit 153 detects the marking and end information of the plate member 2 of the transported object from the acquired transported object image c by image analysis or the like, thereby acquiring the marking position (x m , y m ) and the rotation angle θ.

[0031] (Acquisition of Marking Position) Based on the preset relative positional relationship between the imaging position of the image acquisition mechanism 14 and the driving mechanism 12 or the holding mechanism 11, the position coordinates of the lower left end of the marking (marking position (x m , y mThe following can be determined: )). For marking detection, it is preferable to prepare training data in advance using R-CNN from images of the markings, and then perform object detection using that training data. Alternatively, training data may be created using CNN or YOLO.

[0032] (Getting the rotation angle) In obtaining the rotation angle, an image of the edge of the plate member 2 is binarized, and areas where the brightness gradient exceeds a predetermined value are detected as straight lines. From these detected straight lines, the one with the smallest distance to the position coordinates of the lower left end of the marking is selected. The angle that the selected straight line makes with the x or y axis in the horizontal direction can then be determined as the rotation angle θ. Alternatively, object detection can be performed by creating training data using R-CNN, CNN, YOLO, etc., as a method for detecting the edge of the plate member 2.

[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 set appropriately based on the amount of displacement of the center of gravity position of the plate member 2 due to the tilt of the plate member 2, but it is preferably about 1°. If the rotation angle θ is within the range of less than 1°, there is almost no displacement of the center of gravity position, and the plate member 2 can be lifted stably.

[0034] In the determination in step S110, if the rotation angle θ is less than the tilt angle threshold, the center of gravity position calculation unit 153 determines the marking position (x m ,y m Based on this, the center of gravity position d(x) of the transported object in the planar coordinates of plate member 2 g ,y g ) is calculated (S112). In step S112, the marking position (x m ,y m ) and the dimensions (s,t) and marking attachment position (u,v) of the plate member 2 of the transported object recorded in the information recording unit 152 are used to determine the centroid position d(x) of the transported object in the plane coordinates of the plate member 2. g ,y g The following equations are used to calculate the center of gravity. The center of gravity can be calculated using equations (1) and (2) below.

[0035]

number

[0036] On the other hand, in the determination in step S110, if the rotation angle θ of the plate member 2 is greater than or equal to the tilt angle threshold, the centroid position calculation unit 153 determines the marking position (x m ,y m Based on the rotation angle θ, the center of gravity position d(x) of the transported object in the plane coordinates of the plate member 2 is determined. g ,y g Calculate (S114). At this time, marking position (x m ,y m ) and the rotation angle θ, along with the dimensions (s,t) and marking mounting position (u,v) of the plate member 2 of the transported object recorded in the information recording unit 152, give the center of gravity position d(x) of the transported object of the plate member 2 in planar coordinates. g ,y g The following equations are used to calculate the center of gravity. The center of gravity can be calculated using equations (3) and (4) below.

[0037]

number

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

[0039] In step S116, if the horizontal distance D between the center position b of the holding mechanism and the center of gravity position d of the object being transported is greater than a threshold, 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 amount of movement required to move the center position b of the holding mechanism to the center of gravity position d of the object being transported. Then, it issues a drive command e to move the holding mechanism 11 by this amount of movement. The drive mechanism 12 receives the drive command e and moves the holding mechanism 11. After step S118, the processing from step S102 onwards is repeated.

[0040] On the other hand, in the determination in step S116, if the horizontal distance D between the center position b of the holding mechanism and the center of gravity position d of the object to be transported is less than or equal to a threshold, 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 is completed, the lifting process of the plate member 2 shown in Figure 5 is completed. After the lifting process of the plate member 2 shown in Figure 5, the crane 1 transports the lifted plate member 2 to a desired location. Furthermore, in the manufacturing method of the plate member 2 according to this embodiment, the handling and transport of the plate member 2 is performed using the material handling and transport method according to this embodiment during the manufacturing process of the plate member 2.

[0042] According to the crane 1, cargo handling method, and plate member manufacturing method of this embodiment, when lifting a plate member 2 such as a steel plate with the crane 1, the position of the plate member 2 to be lifted can be accurately detected by reading characteristic parts such as markings attached to the plate member 2. In particular, with conventional cranes using image recognition technology, it was difficult to detect the top plate member from a stack of multiple thin plate members, but according to this embodiment, the position of the top plate member 2 can be detected regardless of the plate thickness. Therefore, the transport operation of the plate member 2 can be made more efficient and labor-saving. Furthermore, by considering the rotation angle θ of the plate member 2, the position of the center of gravity can be accurately detected even if the plate member 2 is installed at an angle in the horizontal direction.

[0043] <Variation> Although the present invention has been described above with reference to specific embodiments, this description is not intended to limit the invention. By referring to the description of the present invention, those skilled in the art will also see other embodiments of the invention, including various modifications, in addition to the disclosed embodiments. Accordingly, the embodiments of the invention described in the claims should be understood to include embodiments that include these modifications described herein, either individually 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 such examples. For example, the crane 1 is preferably an overhead crane mounted on the ceiling, but it may also be a jib crane, a gantry crane, or the like. Furthermore, the crane 1 may simultaneously lift multiple stacked plate members 2. In this case, the crane 1 may use the markings on the uppermost plate member 2 to perform the lifting in the same manner as in the above embodiment.

[0045] Furthermore, although the above embodiment assumes that the characteristic portion of the plate member 2 is a marking such as a product number, the present invention is not limited to such examples. The characteristic portion of the plate member 2 may be anything other than what is attached to the plate member 2 at a specific position and is identifiable from the transported object image c. For example, the characteristic portion of the plate member 2 may be a mark printed for automatic transport by the crane 1, or a QR code (registered trademark) attached as a sticker. When a QR code is used, information about the plate member 2 (such as dimensions) stored in the QR code can also be read. In addition, other characteristic portions such as patterns on the surface of a steel plate may be used. When the plate member 2 is a steel plate, considering the effort required to apply a new marking, it is preferable to use a manufacturing number marking, whose printing position is known, as the characteristic portion. Furthermore, although the plate member 2 is a steel plate in the above embodiment, the present invention is not limited to this example. The plate member 2 may be made of other materials, or have different dimensions and shapes, as long as it is a plate-shaped object that can be lifted and transported using a crane. [Examples]

[0046] To evaluate the lifting capacity controllability of the present invention, the following tests were conducted as examples. In Example 1, the crane 1 was moved according to the following steps [1] to [9], and the center position b of the holding mechanism of the crane 1 after the movement was completed was measured and verified.

[0047] [1] Fifty images were prepared of markings applied to a steel plate, which is plate member 2, taken from a distance of 1 m, and these were used to create training data for marking detection using the R-CNN method. [2] Prepare steel plates measuring 1400mm in width x 2100mm in height and with a thickness of t20, and install three of them stacked on top of each other without tilting them in the position shown in Figure 6. [3] A marking measuring 600mm wide x 300mm high (with the product number etc. written in numbers and letters) is applied using a stencil and spray material, so that the lower 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 rangefinder are attached to Crane 1, which is an overhead crane that travels 10 m above the steel plate. 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 rangefinder corresponds to the self-position detection mechanism 13. [5] The marking position is detected from the image captured by the image acquisition mechanism 14 using training data, and the rotation angle of the steel plate in the horizontal direction is detected from the position of the edge of the steel plate in the image. [6] Since the detected rotation angle is less than the tilt angle threshold (1°), the center of gravity of the transported object of the uppermost steel plate is calculated using the detected marking position and the steel plate dimensions and marking mounting position stored in the information recording unit 152. [7] Move the crane horizontally by the distance between (the center of gravity of the object being transported on the uppermost steel plate) and (the center position of the holding mechanism 11 attached to the crane 1). [8] Use a laser rangefinder to measure the center position of the holding mechanism 11 attached to the crane 1, and repeat steps [6] and [7] until (center position of the transported object on the uppermost steel plate) - (center position of the holding mechanism 11 attached to the crane 1) is within ±20 mm. [9] When finished, the center position of the holding mechanism 11 attached to the crane 1 is measured with a total station.

[0048] Table 1 shows the results of the embodiment. The center position of the holding mechanism 11 was moved almost accurately to the target position, which is the center of gravity of the transported object on the uppermost steel plate. Furthermore, as shown in Figure 7, the same test was conducted by changing the plate thickness of the three installed steel plates from top to bottom to t5, t10, and t20, and the results are shown in Table 2. Similar results were obtained under these conditions as well, indicating that 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 lifting targets for automated transport cranes.

[0049] [Table 1]

[0050] [Table 2]

[0051] Furthermore, as a comparative example, we also verified the case where an overhead crane was moved to lift plate member 2 using a conventional method. In the comparative example, a photograph was taken from a 45° angle (7m above and 7m away in the y-axis direction) using the same 4K camera as in the example, and the center of gravity of the transported object of the uppermost steel plate was calculated by detecting the edge of the steel plate using image processing, and the crane was moved horizontally based on that information. Furthermore, in the comparative example, Table 3 shows the results under the condition of stacking three plates with a thickness of t20, as shown in Figure 6. Under this condition, each steel plate could be separated and detected, and it was confirmed that the center position of the holding mechanism could be moved almost accurately to the target position, which is the center of gravity of the transported object of the top steel plate.

[0052] [Table 3]

[0053] On the other hand, in the comparative example, Table 4 shows the results under conditions where the thickness of the steel plate was changed from top to bottom to t5, t10, and t20, as shown in Figure 7. Under these conditions, the t5 and t10 steel plates could not be separated as separate plates and were detected as a single unit. As a result, the center of gravity of the transported object was detected as a value shifted by approximately 100 mm in the x direction and approximately 200 mm in the y direction, and consequently, the center position of the holding mechanism was shifted from the target position. From this, it can be seen that with this method, the center of gravity cannot be accurately detected for thin steel plates with a thickness of 10 mm or less, and therefore they cannot be used as lifting targets for automated transport cranes.

[0054] [Table 4] [Examples]

[0055] Furthermore, as Example 2, the same verification as in Example 1 was performed under conditions in which the steel plates were installed at an angle. As shown in Figure 8, Table 5 shows the verification results when three steel plates with thicknesses of t5, t10, and t20 were installed at an angle of 5°. In this case, since the rotation angle detected in the procedure in [6] above is greater than or equal to the tilt angle threshold (1°), the position of the center of gravity of the transported object on the uppermost steel plate is calculated from the detected marking position, the rotation angle θ, the steel plate dimensions, and the marking mounting 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 is the center of gravity of the uppermost steel plate being transported. In other words, even if the steel plate is installed at a horizontal inclination, the position of the center of gravity can be detected, and it can be used as a lifting target for the automated transport crane.

[0058] On the other hand, as a comparative example, we also verified the case where the overhead crane was moved to lift 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, it was not possible to separate the t5 and t10 steel plates as separate plates, and they were detected as a single unit. As a result, the center of gravity of the transported object was detected as a value shifted by approximately 140 mm in the x direction and approximately 150 mm in the y direction, making it impossible to use it as a target for lifting by the automated transport crane.

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

[0060] 1 Crane 11 Retention mechanism 12 Drive mechanism 121 Traveling frame 122 Crane Girder 123 Hoisting machine 13 Self-position detection mechanism 14 Image acquisition mechanism 15 Control mechanism 151 Center position calculation section 152 Information Recording Department 153 Center of gravity position calculation section 154 Drive amount calculation unit 2 Plate members 3. Running Rails a. Drive mechanism position b Holding mechanism center position c. Image of the object to be transported d. Center of gravity of the object being transported e Drive command

Claims

1. A crane for handling and transporting plate members, A holding mechanism for lifting and holding the plate member, A drive mechanism for moving the holding mechanism at least horizontally, An image acquisition mechanism that acquires an image of the plate member such that the characteristic portion of the plate member is included, A control mechanism that detects the feature portion from the image, calculates the position of the plate member and the horizontal rotation angle from the position of the feature portion, and adjusts the horizontal position of the holding mechanism based on the position of the plate member and the rotation angle, Equipped with, The aforementioned characteristic portion is the marking applied to a predetermined position on the plate member and the end of the plate member. The control mechanism calculates the rotation angle from the position of the end of the plate member, and calculates the position of the plate member as the center of gravity of the plate member, based on at least the dimensions of the plate member and the position of the marking.

2. The control mechanism calculates the position of the plate member, specifically the center of gravity of the plate member, based on the dimensions of the plate member and the position of the marking, when the rotation angle is less than the tilt angle threshold. The crane according to claim 1.

3. The crane according to claim 1, 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 position of the marking, and the rotation angle when the rotation angle is greater than or equal to a tilt angle threshold.

4. The crane according to any one of claims 1 to 3, wherein the control mechanism selects the end of the plate member closest to the marking as the end of the plate member, and calculates the rotation angle from the inclination of the selected end with respect to the direction of movement of the holding mechanism.

5. The holding mechanism further comprises a self-position detection mechanism for detecting the center position in the horizontal direction of the holding mechanism, The control mechanism provides a drive command to the drive mechanism such that the distance between the center of gravity of the plate member and the center of the holding mechanism is less than or equal to a threshold. The crane according to any one of claims 1 to 3.

6. The building further includes a running rail installed on the ceiling of the building where the aforementioned plate members are stored. The drive mechanism to which the holding mechanism is attached is moved along the running rail, thereby moving the holding mechanism horizontally. The crane according to any one of claims 1 to 3.

7. The crane according to claim 6, wherein the image acquisition mechanism is attached to the drive mechanism.

8. A method of transporting plate members, A step of acquiring an image of the plate member such that the characteristic portion of the plate member is included, A step of detecting the feature portion from the image and calculating the position of the plate member and the horizontal rotation angle from the position of the feature portion, A step of adjusting the horizontal position of the holding mechanism that lifts and holds the plate member based on the position of the plate member and the rotation angle, After adjusting the horizontal position of the holding mechanism, the plate member is lifted and transported. Equipped with, The aforementioned characteristic portion is defined as the markings attached to a predetermined position on the plate member and the end of the plate member. A transport method in which, in the step of adjusting the horizontal position of the holding mechanism, the rotation angle is calculated from the position of the end of the plate member, and the position of the plate member is calculated as the center of gravity of the plate member from at least the dimensions of the plate member and the position of the marking.

9. A method for manufacturing a plate member, comprising using a crane according to any one of claims 1 to 3 to handle and transport the plate member in a manufacturing process for manufacturing the plate member.

Images