This application claims priority to Japanese Patent Application No. 2022-085055 filed on May 25, 2022, incorporated herein by reference in its entirety.
The present disclosure relates to an inspection system for a welded portion.
In welding, various techniques used for inspection of welding quality have been proposed. For example, Japanese Unexamined Patent Application Publication No. 11-090643 (JP 11-090643 A) discloses a technique for displaying a welded portion determined to be poor welding on a 3D graphic of a welded object.
However, when the poor welding is caused by the positional deviation of the welded portion, the deviation amount is measured manually by the inspector with reference to 2D design drawings. The 2D design drawings are shown in reduced size. Therefore, the inspector is required to have skills to determine the correspondence and direction between the design drawing and the actual welded object. Further, the inspection results are written on paper and stored. From the viewpoint of efficiency improvement and cost reduction, paperless recording of the inspection results is required. Therefore, there is a demand for a technique capable of easily inspecting a welded portion and storing an inspection result in a paperless manner.
The present disclosure can be realized in the following aspects.
(1) According to an aspect of the present disclosure, an inspection system for a welded portion is provided. The inspection system includes: a display unit; an acquisition unit that acquires a reference position of the welded portion stored in a storage device; a display control unit that causes the display unit to virtually superimpose a reference position image on a captured image to display the reference position image, the captured image being a captured image of a welded object in a real space captured by an imaging device, the captured image being a captured image including the welded portion, and the reference position image being an image indicating the reference position; and a distance calculation unit that calculates a distance in the real space between the welded portion in the real space displayed on the display unit and the reference position of the welded portion. According to the inspection system of this aspect, the reference position of the welded portion stored in the storage device is virtually superimposed on the captured image of the welded portion in the real space captured by the imaging device, as an image to be displayed. The distance calculation unit calculates the distance between the displayed welded portion and the reference position of the welded portion in the real space. This makes it easier to inspect the welded portion as compared with the case where the inspector manually measures the distance. The reference position image is superimposed and displayed on the captured image including the welded portion. This makes it possible to easily inspect the welded portion without depending on the skill of reading and interpreting the 2D design drawing.
(2) The inspection system according to the above aspect may further include a result storage unit that stores the distance calculated by the distance calculation unit.
According to the inspection system of this aspect, the result storage unit stores the distance calculated by the distance calculation unit. This makes it possible to store the calculated distance in a paperless manner.
(3) In the inspection system according to the above aspect, the display control unit may further cause the display unit to display a coordinate axis. The coordinate axis includes a first axis extending along a first direction and a second axis extending along a second direction perpendicular to the first direction.
According to the inspection system of this aspect, since the coordinate axes orthogonal to each other are displayed on the display unit, the inspector can confirm the direction of the welded object on the display unit.
(4) The inspection system according to the above aspect may further include a determination unit that determines whether welding of the welded portion in the real space is good using the distance calculated by the distance calculation unit. The determination unit may determine that the welding good when the distance is a distance within a predetermined threshold, and determine that the welding is poor when the distance is a distance that exceeds the predetermined threshold.
According to the inspection system of this aspect, the determination unit compares the distance calculated by the distance calculation unit with the predetermined threshold to determine whether the welding is good. This makes it easier to inspect the welding as compared with a case where the inspector manually determines whether the welding is good. In addition, it is possible to determine whether the welding is good in the inspection without being influenced by the inspection skill of the inspector.
(5) The inspection system according to the above aspect may further include a correction amount calculation unit that calculates a correction amount of a distance using the distance calculated by the distance calculation unit. The correction amount of the distance is an amount of a distance required for re-welding the welded portion in the real space at the reference position of the welded portion.
According to the inspection system of this aspect, the correction amount calculation unit calculates the correction amount of the distance necessary for re-welding at the reference position of the welded portion. This makes it easier to acquire the correction amount as compared with the case where the inspector calculates the correction amount.
(6) The inspection system according to the above aspect may further include a user interface that allows the reference position image displayed on the display unit to be moved on the captured image. When the reference position image is moved so as to overlap the welded portion in the captured image using the user interface, the distance calculation unit may calculate the distance using a movement amount of the reference position image.
According to the inspection system of this aspect, the reference position image on the captured image is moved so as to overlap the welded portion via the user interface, and the distance calculation unit calculates the distance by using the movement amount. Therefore, the inspector can easily calculate the distance while confirming the welded portion and the reference position of the welding.
The present disclosure can also be implemented in various forms other than an inspection system for a welded portion. For example, the present disclosure can be implemented in the form of an inspection method for a welded portion, a computer program for realizing an inspection method for a welded portion, a non-transitory recording medium in which the computer program is recorded, and the like.
Features, advantages, and technical and industrial significance of exemplary embodiments of the present disclosure will be described below with reference to the accompanying drawings, in which like signs denote like elements, and wherein:
A1. System Configuration
The memory 1 includes, for example, a Dynamic Random Access Memory (DRAM, a flash memory, and the like, and stores a control program for operating the inspection system 100. The memory 1 is used as a temporary storage area for various data such as imaging data. Further, the memory 1 is also used as a work area when each unit of the inspection system 100 performs an operation. Central Processing Unit (CPU) 2 is a processor that controls the entire inspection system 100. CPU 2 reads and executes the control program from the memory 1. As a result, CPU 2 functions as the acquisition unit 3, the display control unit 7, and the distance calculation unit 8.
The acquisition unit 3 acquires the reference position of the welded portion stored in the storage device 4. The storage device 4 stores CAD data (also referred to as 3D CAD data) of the three-dimensional model of the welded object W. 3D CAD is a design model generated by CAD software in the design process. The design process is performed prior to the welding process. 3D CAD is stored in advance in the storage device 4. 3D CAD data includes information indicating a position of a welded portion of the welded object W. In the present embodiment, the position of the welded portion included in 3D CAD is referred to as a reference position of the welded portion. The storage device 4 is, for example, a Hard Disc Drive (HDD). The acquisition unit 3 also acquires the reference position of the welded portion by acquiring 3D CAD data.
The display unit 6 displays the imaging controlled by the display control unit 7. The display control unit 7 acquires an image of the welded object W captured by the imaging device 5. The display control unit 7 virtually superimposes the reference position acquired by the acquisition unit 3 on the captured image as a reference position image, and displays the image on the display unit 6. The imaging device 5 captures an image of the welded object W in the real space. The display control unit 7 virtually superimposes the reference position of the welding position acquired by the acquisition unit 3 on the imaging as a reference position image, and displays it on the display unit 6. In the present embodiment, the reference position image is a circular image having a predetermined radius centered on the reference position. Details of the reference position image will be described later. In this way, a technique of virtually superimposing images such as 3D images on a captured image is called an AR. The registration of the superimposed images is performed by known AR techniques. Such techniques are, for example, marker-type AR or marker-less type AR. The marker type AR uses a patterned pattern or a QR code (registered trademark) set in advance as a marker. The marker type AR performs alignment by recognizing a marker. In the marker-less AR, feature points or feature lines being imaged are recognized. Thus, the marker-less AR performs alignment.
The distance calculation unit 8 calculates a distance between the welded portion in the real space displayed on the display unit 6 and the reference position of the welded portion in the real space. The distance is calculated by a known AR technique. Such techniques are, for example, Simultaneous Localization and Mapping (SLAM). In SLAM, a plurality of feature points being imaged are extracted, and the distance between the imaging device 5 and the feature point is measured. The coordinate space is set by determining the coordinates of each feature point based on the distance. By setting the coordinate space, the distance in the real space between any two points during imaging can be obtained. In the present embodiment, the distance between the welded portion being imaged and the reference position of the overlapped welded portion in the real space is calculated. That is, the calculated distance is the amount of deviation between the welded portion defined in the design drawing and the welded portion where welding is actually performed. Further, the distance calculation unit 8 may calculate a distance for each axis in the set coordinate space. Specifically, the distance calculation unit 8 may calculate a distance for each of any two axes selected from the X axis, the Y axis, and the Z axis. The distance calculated by the distance calculation unit 8 is stored in the result storage unit 9. The result storage unit 9 is, for example, a HDD.
A2. Inspection Method for Welded Portion
The acquisition unit 3 obtains the reference position of the welded portion (step S105). As described above, the acquisition unit 3 acquires the reference position of the welded portion from the storage device 4. When the storage device 4 stores 3D CAD of a plurality of types of welded objects W, the acquisition unit 3 recognizes feature points, feature lines, markers, or the like of the welded object W imaged by the imaging device 5. Thus, the acquisition unit 3 may specify the welded object W to be inspected and acquire the corresponding 3D CAD.
The display control unit 7 acquires an image of the welded object W in the real space, the image including the welded portion (step S110). The imaging may be performed by the imaging device 5. Alternatively, the imaging may be stored in advance in the storage device 4. Hereinafter, a case where imaging is performed by the imaging device 5 will be described.
The display control unit 7 virtually superimposes the reference position images indicating the reference positions of the welded portions on the images acquired in the step S110 (step S115). The display control unit 7 virtually superimposes the reference position image indicating the reference position on the image of the welded object W including the welded portion. The images to be superimposed can be aligned using the known AR techniques described above.
The distance calculation unit 8 calculates a distance between the welded portion in the real space and the reference position of the welded portion in the real space (step S120). The distance calculation unit 8 uses, for example, a SLAM as described above. The distance calculation unit 8 calculates a distance in the real space between the welded portion P1 displayed on the display unit 6 and the reference position image P2. The calculated distance is a distance D1 between the center C1 of the welded portion P1 and the center C2 of the reference position image P2. That is, the calculated distance D1 is a deviation amount from the welded portion defined in the design drawing of the welded portion where welding is actually performed.
The result storage unit 9 stores the distance calculated by the distance calculation unit 8 (step S125). The result storage unit 9 stores the distance calculated by the distance calculation unit 8 as a shift amount of the welded portion PT.
According to the inspection system 100 described above, the reference position image is virtually superimposed on the imaging including the welded portion. Then, the inspection system 100 calculates the distance between the welded portion and the reference position of the welded portion in the real space. Therefore, in the post-welding inspection process, the inspection system 100 can measure the amount of deviation of the welded portion from the imaging including the welded portion and the information on the reference position of the welded portion. In addition, the inspection system 100 can inspect the welded portion in a simple and short time as compared with the manual inspection by the inspector I which has been conventionally performed.
Further, according to the inspection system 100, the reference position of the welded portion is superimposed on the imaging including the welded portion and displayed. Therefore, the inspector I can easily confirm the correspondence between the welded object W and the design drawing without depending on the skill of reading and interpreting 2D design drawing, and can inspect the welded portion. Furthermore, the time and cost required for the education of the inspection work by the inspector I can be reduced.
Further, according to the inspection system 100, the result storage unit 9 stores the distance calculated by the distance calculation unit 8 as a shift amount. Therefore, the inspection record can be stored in a paperless manner.
The first axis and the second axis are any different axes selected from the X axis, the Y axis, and the Z axis. The X-axis and the Z-axis in
According to the inspection system 100a of the second embodiment described above, since the coordinate axis AX is displayed on the display unit 6, the inspector I can confirm the orientation of the welded object W being imaged.
The display control unit 7 displays the distance calculated by the distance calculation unit 8 on the display unit 6. In
According to the inspection system 100b of the third embodiment described above, the distance between the welded portion in the real space and the reference position of the welded portion in the real space is displayed on the display unit 6. Therefore, the inspector I can immediately confirm the amount of deviation of the welded portion.
The determination unit 11 compares the distance between the welded portion in the real space and the reference position of the welded portion in the real space with the threshold value. The threshold value is an allowable upper limit value of the amount of deviation of the welded portion. The thresholds are preset and are, for example, 1 cm. The determination unit 11 determines the quality of the welding according to the comparison result. The result of the determination may be stored in the result storage unit 9.
The determination unit 11 determines whether or not the distance between the welded portion in the real space and the reference position of the welded portion in the real space is within a predetermined threshold (step S205). The determination unit 11 compares the distance calculated by the distance calculation unit 8 with a threshold value set in advance. When the determination unit 11 determines that the distance is less than or equal to the threshold value (step S205: YES), the determination unit 11 determines that the welding is performed satisfactorily (step S210). On the other hand, when the determination unit 11 determines that the distance exceeds the threshold value (step S205: NO), the determination unit 11 determines that the weld is defective (step S215).
According to the inspection system 100c of the fourth embodiment described above, the determination unit 11 determines whether the welding is good or bad by comparing the displacement of the welded portion with the set thresholds. Therefore, in the welding inspection process, the inspection system 100c can easily determine the quality of the welding without depending on the skill of the inspector I, as compared with the case where the inspector I manually measures the displacement amount and determines the quality of the welding.
The inspection method for the welded portion described in the first embodiment may further include a step of the correction amount calculation unit 12 calculating the correction amount. In such cases, the step of calculating the correction amount is performed after the step of calculating the distance (step S120).
According to the inspection system 100d of the fifth embodiment described above, the correction amount calculation unit 12 is provided. Therefore, the inspector I confirms the correction amount calculated by the correction amount calculation unit 12, so that the inspector I can immediately understand the correction amount necessary for re-welding the welded portion.
The inspection system 100e according to the sixth embodiment differs from the inspection system 100 according to the first embodiment in that the display control unit 7 causes the display unit 6 to display the distance calculated by the distance calculation unit 8 and the result determined by the determination unit 11. The remaining configuration of the inspection system 100e of the sixth embodiment is the same as that of the inspection system 100 of the first embodiment. Therefore, the same components are denoted by the same reference numerals, and the description thereof will be omitted.
According to the inspection system 100e of the sixth embodiment, the display unit 6 displays the distance calculated by the distance calculation unit 8 and the determination result determined by the determination unit 11. Therefore, the inspector I can confirm at a glance the displacement amount of the welded portion and the quality of the welding. Further, it is also possible to collectively confirm additional information such as an image including a welded portion, an inspection date, a name of the inspector I, an ID of the welding robots, and a product number of the welded object W.
The inspection system 100f according to the seventh embodiment differs from the inspection system 100 according to the first embodiment in that it further comprises a user interface allowing the reference position image P2 to be moved on imaging. In addition, the inspection system 100 according to the first embodiment differs from the inspection system in that the distance calculation unit 8 calculates the distance by using the moving amount of the reference position image P2 when the reference position image P2 is moved so as to overlap with the welded portion in the imaging using the user interface. The remaining configuration of the inspection system 100f of the seventh embodiment is the same as that of the inspection system 100 of the first embodiment. Therefore, the same components are denoted by the same reference numerals, and the description thereof will be omitted.
The inspection system 100f according to the seventh embodiment described above includes a user interface that allows the reference position image P2 to be moved during imaging. Further, in the inspection system 100f, the distance calculation unit 8 calculates the distance according to the moving amount of the reference position image P2. With such a configuration, as in the inspection system 100 described in the first embodiment, it is possible to easily inspect the welded portion. In addition, the inspector I directly operates through the user interface. Therefore, the inspector I can measure the distance between the welded portion and the reference position while visually checking. In addition, a grid GR is displayed. Therefore, the inspector I can measure the distance while checking the distance in the real space being imaged displayed on the display unit 6. In addition, the coordinate axis AX is rotatably displayed by the user interface. Therefore, the inspector I can measure the distance while aligning the axes.
The inspection system 100g according to the eighth embodiment differs from the inspection system 100f according to the seventh embodiment in that the reference position image P2 is moved by touching the reference position image P2 displayed on the display unit 6.
With the inspection system 100g according to the eighth embodiment described above, similarly to the inspection system 100f according to the seventh embodiment, the distance between the welded portion and the reference position can be calculated using the displacement of the reference position image P2.
(I1) In each embodiment, the information stored in the result storage unit 9 may be stored in a storage device external to the inspection system 100. That is, the distance calculated by the distance calculation unit 8, the determination result determined by the determination unit 11, and the correction amount calculated by the correction amount calculation unit 12 may be stored in a storage device outside the inspection system 100. The external storage device is, for example, a server, a HDD, or the like. In such a case, the inspection system 100 may include a communication unit for communicating with an external server or the like. In such a case, the inspection system 100 may not have the result storage unit 9.
(I2) In each embodiment, the display unit 6 may display at least one of the distance calculated by the distance calculation unit 8, the determination result determined by the determination unit 11, and the correction amount calculated by the correction amount calculation unit 12. In addition, the display unit 6 may display two or more of these.
(I3) In each of the embodiments, the configuration in which the inspection system 100 includes the storage device 4 and the imaging device 5 has been described. However, instead of this configuration, the storage device 4 and the imaging device 5 may be provided outside the inspection system 100. That is, in the inspection system 100, the storage device 4 and the imaging device 5 are not essential components. In such a case, the inspection system 100 may include a communication unit for communicating with the external storage device 4 and the imaging device 5.
(I4) In the seventh embodiment, a configuration in which the user interface is a touch panel has been described. However, any user interface may be used instead of the touch panel. For example, the user interface may be a gesture interface operable by a gesture. The user interface may be a mouse or a keyboard.
The present disclosure is not limited to each of the above embodiments, and can be realized by various configurations without departing from the spirit thereof. For example, the technical features in the embodiments corresponding to the technical features in the embodiments described in SUMMARY can be appropriately replaced or combined in order to solve some or all of the above-described problems or to achieve some or all of the above-described effects. Further, when the technical features are not described as essential in the present specification, these can be deleted as appropriate.
Number | Date | Country | Kind |
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2022-085055 | May 2022 | JP | national |