Weld line generating device, weld line generating method, and recording medium

Abstract

The present invention provides a welding line generation device, a welding line generation method, and a welding line generation program that can automatically generate welding lines without using three-dimensional CAD data. The welding line generation device (S) of the present invention comprises: a point cloud data acquisition unit (1) that acquires three-dimensional point cloud data of a plurality of workpieces to be welded arranged in a predetermined space; an edge extraction unit (22) that extracts three-dimensional point cloud data of edges from the three-dimensional point cloud data acquired by the point cloud data acquisition unit (1); a workpiece point cloud data generation unit (23) that generates three-dimensional point cloud data of each of the plurality of workpieces based on the three-dimensional point cloud data obtained by the point cloud data acquisition unit (1) after deleting the three-dimensional point cloud data of the edges extracted by the edge extraction unit (22); and a welding line generation unit (24) that generates welding lines for the plurality of workpieces based on the three-dimensional point cloud data of each of the plurality of workpieces generated by the workpiece point cloud data generation unit (23).

Description

Technical Field

[0001] The present invention relates to a weld line generating device, a weld line generating method, and a weld line generating program for generating weld lines for a plurality of workpieces to be welded. Background Art

[0002] For example, the development of multi-jointed robots, such as vertical six-axis robots, has led to the automation of welding, with welding torches being attached to the tip of the robot arm. These multi-jointed robots operate according to pre-taught motion data (motion programs, teaching data, and teaching programs). Automation of welding requires the generation of this motion data, and to achieve this, there is a desire to automatically generate weld lines, such as the technology disclosed in Patent Document 1.

[0003] The welding pass determination method disclosed in patent document 1 determines the welding passes of components constituting a ship hull, i.e., at least two welded components, wherein the welding pass determination method includes: a step of determining a first welded component and a second welded component that can contact each other based on the shapes of the welded components in three-dimensional CAD data; a step of extracting a first surface of the second welded component that contacts one surface of the first welded component and has a normal vector parallel to the normal vector of the one surface; a step of extracting a second surface of the second welded component; a step of extracting a common edge shared by the first surface and the second surface; and a step of determining the welding passes of welding the first welded component and the second welded component corresponding to the common edge.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Publication No. 2018-156566

[0007] However, the welding pass determination method disclosed in Patent Document 1 requires pre-production of three-dimensional CAD data, leaving room for improvement. On the other hand, it is also conceivable for an operator (user) to manually generate the motion data, but this process is time-consuming (man-hours) and prone to errors in motion data generation by unskilled operators. Summary of the Invention

[0008] Problems to be solved by the invention

[0009] The present invention has been made in view of the above-mentioned circumstances, and an object of the present invention is to provide a weld line generation device, a weld line generation method, and a weld line generation program capable of automatically generating weld lines without using three-dimensional CAD data.

[0010] Solutions to Problems

[0011] As a result of various studies, the inventors have discovered that the above-mentioned object is achieved by the following invention. Specifically, a weld line generation device according to one aspect of the present invention comprises: a point cloud data acquisition unit that acquires three-dimensional point cloud data of a plurality of workpieces to be welded, arranged in a predetermined space; an edge extraction unit that extracts three-dimensional point cloud data of edges from the three-dimensional point cloud data acquired by the point cloud data acquisition unit; a workpiece point cloud data generation unit that generates three-dimensional point cloud data for each of the plurality of workpieces based on the three-dimensional point cloud data acquired by the point cloud data acquisition unit by removing the three-dimensional point cloud data of the edges extracted by the edge extraction unit; and a weld line generation unit that generates weld lines for the plurality of workpieces based on the three-dimensional point cloud data for each of the plurality of workpieces generated by the workpiece point cloud data generation unit.

[0012] Such a weld line generation device generates weld lines based on three-dimensional point cloud data of a plurality of workpieces to be welded, and therefore can automatically generate weld lines without using three-dimensional CAD data.

[0013] In another embodiment, in addition to the above-described weld line generation device, the weld line generation unit performs determination processing on all combinations of two workpieces in the respective three-dimensional point cloud data of the plurality of workpieces generated by the workpiece point cloud data generation unit. The determination processing is as follows: selecting three-dimensional point cloud data of two workpieces from the respective three-dimensional point cloud data of the plurality of workpieces generated by the workpiece point cloud data generation unit, and, if a distance between ends of either of the two selected workpieces is less than a predetermined threshold, determining that the two selected workpieces are adjacent workpieces having adjacent ends, and generating the weld line between the adjacent ends of the two workpieces determined to be adjacent by the determination processing.

[0014] Such a weld line generating device can identify two adjacent workpieces having respective ends adjacent to each other and can automatically generate a weld line.

[0015] In another embodiment, in the aforementioned weld line generation device, the weld line generation unit performs generation processing for all of the two workpieces determined to be adjacent to each other by the determination processing. The generation processing is as follows: for each endpoint of each adjacent end portion of the two workpieces determined to be adjacent to each other by the determination processing, a candidate weld line point is generated between the endpoint of one of the two workpieces and the endpoint of the other of the two workpieces closest to the endpoint, and a fitting line is generated as the weld line by fitting each of the generated candidate points. Preferably, in the aforementioned weld line generation device, the weld line generation unit generates the candidate weld line point at a central position (midpoint position) between the endpoint and the endpoint closest to the endpoint.

[0016] Such a weld line generation device can generate a weld line using a fitting line that is fitted to each candidate point.

[0017] In another embodiment, based on the above-described weld line generation device, the weld line generation unit groups candidate points for generating the fitted line with the inflection point as a boundary when the fitted line has an inflection point, and generates a fitted straight line fitted to each candidate point as the weld line for each group.

[0018] Such a weld line generating device divides the weld line of the fitting line at the bending point and regenerates the weld line into a plurality of weld lines, and thus can generate a more appropriate weld line according to the shape of the end portion of the workpiece.

[0019] In another embodiment, the weld line generation device described above further includes a weld line elimination unit that eliminates short weld lines having a value less than or equal to a predetermined second threshold value from the weld lines generated by the weld line generation unit. Preferably, the weld line generation device described above further includes an input unit that receives input of the second threshold value, and the weld line elimination unit uses the second threshold value received by the input unit.

[0020] Such a weld line generating device further includes a weld line excluding device, and thus can exclude weld lines that are unlikely to be actually used for welding.

[0021] In another embodiment, the weld line generation device described above further includes a second weld line elimination unit for eliminating weld lines outside a predetermined range from the weld lines generated by the weld line generation unit. Preferably, the weld line generation device described above further includes a second input unit for receiving input of the range, wherein the second weld line elimination unit uses the range received by the second input unit.

[0022] Such a weld line generating device further includes the second weld line exclusion portion, and therefore can exclude weld lines that are unlikely to be actually used for welding.

[0023] In another embodiment, the aforementioned weld line generating apparatus further includes a weld line merging unit configured to merge the weld lines generated by the weld line generating unit into a single weld line by connecting the weld line to the weld line generated by the weld line generating unit when a distance between a first end point of one weld line and a second end point of the other weld line is equal to or smaller than a predetermined third threshold value.

[0024] Such a weld line generating device further includes a weld line merging unit, and thus can generate a more appropriate weld line.

[0025] A welding line generation method according to one embodiment of the present invention comprises: a point cloud data acquisition step for acquiring three-dimensional point cloud data of a plurality of workpieces to be welded arranged in a predetermined space; an edge extraction step for extracting three-dimensional point cloud data of edges from the three-dimensional point cloud data acquired in the point cloud data acquisition step; a workpiece point cloud data generation step for generating three-dimensional point cloud data for each of the plurality of workpieces based on the three-dimensional point cloud data obtained by deleting the three-dimensional point cloud data of the edges extracted in the edge extraction step from the three-dimensional point cloud data acquired in the point cloud data acquisition step; and a welding line generation step for generating welding lines for the plurality of workpieces based on the three-dimensional point cloud data for each of the plurality of workpieces generated in the workpiece point cloud data generation step.

[0026] A welding line generation program according to one embodiment of the present invention causes a computer to execute the following steps: a point cloud data acquisition step for acquiring three-dimensional point cloud data of a plurality of workpieces to be welded arranged in a predetermined space; an edge extraction step for extracting three-dimensional point cloud data of edges from the three-dimensional point cloud data acquired in the point cloud data acquisition step; a workpiece point cloud data generation step for generating three-dimensional point cloud data for each of the plurality of workpieces based on the three-dimensional point cloud data obtained by deleting the three-dimensional point cloud data of the edges extracted in the edge extraction step from the three-dimensional point cloud data acquired in the point cloud data acquisition step; and a welding line generation step for generating welding lines for the plurality of workpieces based on the three-dimensional point cloud data for each of the plurality of workpieces generated in the workpiece point cloud data generation step.

[0027] Such a weld line generation method and weld line generation program generate weld lines based on three-dimensional point cloud data of a plurality of workpieces to be welded, and thus can automatically generate weld lines without the need for three-dimensional CAD data.

[0028] Effects of the Invention

[0029] The weld line generation device, weld line generation method, and weld line generation program of the present invention can automatically generate weld lines without using three-dimensional CAD data. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 This is a block diagram showing the configuration of a weld line generating device according to an embodiment.

[0031] Figure 2 This is a diagram showing three-dimensional point cloud data of a workpiece as an example.

[0032] Figure 3 Is used to explain the Figure 2 Figure 2 shows the edges detected from the 3D point cloud data.

[0033] Figure 4 It is used to illustrate the Figure 2 Figure 3D point cloud data of a workpiece generated from the three-dimensional point cloud data shown.

[0034] Figure 5 It is a diagram for explaining two adjacent workpieces having their respective ends adjacent to each other.

[0035] Figure 6 It is used to illustrate the Figure 2 A diagram of candidate points for a weld line generated from the three-dimensional point cloud data shown.

[0036] Figure 7 It is used to illustrate the Figure 2 Figure 1 shows a weld line diagram generated from the 3D point cloud data shown.

[0037] Figure 8 1 is a flowchart showing the operation of the weld line generating device.

[0038] Description of Reference Numerals

[0039] S welding line generator

[0040] 1. Point cloud data acquisition department

[0041] 2 Control processing unit

[0042] 3 Input section

[0043] 4 Output section

[0044] 5 Interface unit (IF unit)

[0045] 6 Storage

[0046] 21 Control Unit

[0047] 22 Edge extraction unit

[0048] 23 Workpiece point cloud data generation department

[0049] 24 Welding line generation unit

[0050] 26 The first welding line except the outside

[0051] 27 The second welding line except the outside

[0052] 28 Welding line merging section. DETAILED DESCRIPTION

[0053] Hereinafter, one or more embodiments of the present invention will be described with reference to the accompanying drawings. However, the scope of the invention is not limited to the disclosed embodiments. It should be noted that in each figure, structures marked with the same reference numerals are represented as the same structures, and their descriptions are appropriately omitted. In this specification, in the case of general terms, they are represented by reference numerals with suffixes omitted, and in the case of referring to individual structures, they are represented by reference numerals with suffixes marked.

[0054] A weld line generation device according to an embodiment generates weld lines for a plurality of workpieces to be welded. The weld line generation device includes: a point cloud data acquisition unit that acquires three-dimensional point cloud data of a plurality of workpieces to be welded, arranged in a predetermined space; an edge extraction unit that extracts three-dimensional point cloud data of edges from the three-dimensional point cloud data acquired by the point cloud data acquisition unit; a workpiece point cloud data generation unit that generates three-dimensional point cloud data for each of the plurality of workpieces based on the three-dimensional point cloud data acquired by the point cloud data acquisition unit, after deleting the three-dimensional point cloud data of the edges extracted by the edge extraction unit; and a weld line generation unit that generates weld lines for the plurality of workpieces based on the three-dimensional point cloud data for each of the plurality of workpieces generated by the workpiece point cloud data generation unit. This weld line generation device, a weld line generation method, and a weld line generation program incorporated in the weld line generation device will be described in more detail below.

[0055] Figure 1 This is a block diagram showing the configuration of a weld line generating device according to an embodiment. Figure 2 This is a diagram showing three-dimensional point cloud data of a workpiece as an example. Figure 3 Is used to explain the Figure 2 Figure 2 shows the edges detected from the 3D point cloud data. Figure 4 It is used to illustrate the Figure 2 Figure 3D point cloud data of a workpiece generated from the three-dimensional point cloud data shown. Figure 5 It is a diagram for explaining two adjacent workpieces having their respective ends adjacent to each other. Figure 6 It is used to illustrate the Figure 2 A diagram of candidate points for a weld line generated from the three-dimensional point cloud data shown. Figure 7 It is used to illustrate the Figure 2 Figure 1 shows a weld line diagram generated from the 3D point cloud data shown.

[0056] The welding line generating device S of the embodiment is, for example, Figure 1 As shown, the system includes a point cloud data acquisition unit 1 , a control processing unit 2 , an input unit 3 , an output unit 4 , an interface unit (IF unit) 5 , and a storage unit 6 .

[0057] The point cloud data acquisition unit 1 is connected to the control processing unit 2 and, under the control of the control processing unit 2, acquires three-dimensional point cloud data of multiple workpieces to be welded, arranged in a predetermined space. The point cloud data acquisition unit 1 outputs the acquired three-dimensional point cloud data of the multiple workpieces to the control processing unit 2. The workpieces to be welded may be any weldable member, such as steel plates. The three-dimensional point cloud data is the three-dimensional coordinate values ​​of each point when the surface of an object is represented by a collection of points. The point cloud data acquisition unit 1 is, for example, a point cloud data generation device that generates three-dimensional point cloud data of an object using a ToF (Time of Flight) camera, a stereo camera, or a LiDAR (Light Detection and Ranging, Laser Imaging Detection and Ranging) camera. If the workpiece to be welded is larger than the range within which a ToF camera or the like can acquire data, three-dimensional point cloud data is generated for each portion of the workpiece, and the three-dimensional point cloud data for each portion is merged.

[0058] It should be noted that the point cloud data acquisition unit 1 may also generate three-dimensional point cloud data of the object using a light section method by scanning slit light in a direction orthogonal to the direction in which the slit light extends. Alternatively, for example, the point cloud data acquisition unit 1 may be an interface circuit for inputting and outputting data to and from an external device. In this case, the external device is a storage medium storing three-dimensional point cloud data of multiple workpieces to be welded arranged in a predetermined space. Examples of such storage media include USB (Universal Serial Bus) memory and SD cards (registered trademark). Alternatively, for example, the point cloud data acquisition unit 1 may be a drive device that reads data from a recording medium storing three-dimensional point cloud data of multiple workpieces to be welded arranged in a predetermined space. In this case, examples of such recording media include CD-ROMs (Compact Disc Read Only Memory), CD-Rs (Compact Disc Recordable), DVD-ROMs (Digital Versatile Disc Read Only Memory), and DVD-Rs (Digital Versatile Disc Recordable). Alternatively, for example, the point cloud data acquisition unit 1 can also be a communication interface circuit that sends and receives communication signals with an external device. In this case, the external device is a server device that is connected to the communication interface circuit via a network (WAN (Wide Area Network, including a public communication network), LAN (Local Area Network), etc.) and manages three-dimensional point cloud data of multiple workpieces of welding objects arranged in a specified space.

[0059] The input unit 3 is a device connected to the control processing unit 2 and inputs various commands, such as commands to start weld line generation, and various data required for operating the weld line generation unit S, such as weld line file names, into the weld line generation unit S. Examples of the device include a plurality of input switches assigned with predetermined functions, a keyboard, and a mouse. The output unit 4 is a device connected to the control processing unit 2 and outputs commands and data input from the input unit 3, as well as generated weld lines, according to the control of the control processing unit 2. Examples of the device include a display device such as a CRT monitor, a liquid crystal display, or an organic EL display, and a printing device such as a printer.

[0060] It should be noted that the input unit 3 and the output unit 4 may also constitute a so-called touch panel. In such a touch panel, the input unit 3 is, for example, a position input device using a resistive film or electrostatic capacitance method that detects an operation position and performs input, and the output unit 4 is a display device. In such a touch panel, the position input device is provided on the display surface of the display device, and one or more input content candidates are displayed on the display device. When a user touches a display position showing the desired input content, the position input device detects the position, and the content displayed at the detected position is input to the weld line generation device S as the user's operation input content. With such a touch panel, the user can easily and intuitively understand the input operation, thereby providing a weld line generation device S that is easy for the user to operate.

[0061] The IF unit 5 is a circuit connected to the control processing unit 2 and performs data input and output with external devices under the control of the control processing unit 2. Examples include an interface circuit for RS-232C, a serial communication method, an interface circuit using the Bluetooth (registered trademark) standard, an interface circuit for infrared communication such as the IrDA (Infrared Data Association) standard, and an interface circuit using the USB (Universal Serial Bus) standard. Alternatively, the IF unit 5 may be a circuit for communicating with external devices, such as a data communication card or a communication interface circuit compliant with the IEEE 802.11 standard.

[0062] It should be noted that, when the point cloud data acquisition unit 1 is an interface circuit or a communication interface circuit, the IF unit 5 may also serve as the point cloud data acquisition unit 1 .

[0063] The storage unit 6 is a circuit connected to the control processing unit 2 and stores various predetermined programs and various predetermined data in accordance with the control of the control processing unit 2. Examples of these various predetermined programs include a control processing program, which includes, for example, a control program for controlling each of the components 1, 3, to 6 of the weld line generation device S; an edge extraction program for extracting edges from the three-dimensional point cloud data acquired by the point cloud data acquisition unit 1; a workpiece point cloud data generation program for generating three-dimensional point cloud data for each of the plurality of workpieces based on the three-dimensional point cloud data acquired by the point cloud data acquisition unit 1 after deleting the edges extracted by the edge extraction program; a weld line generation program for generating weld lines for the plurality of workpieces based on the three-dimensional point cloud data for each of the plurality of workpieces generated by the workpiece point cloud data generation program; and a teaching data generation program for generating teaching data (motion data) for operating a multi-joint robot equipped with a welding torch based on the weld lines generated by the weld line generation program. Examples of these various predetermined data include data required for executing each of the aforementioned programs. Such a storage unit 6 includes, for example, a nonvolatile ROM (Read Only Memory) or a rewritable nonvolatile EEPROM (Electrically Erasable Programmable Read Only Memory). Furthermore, the storage unit 6 includes a RAM (Random Access Memory), which serves as the so-called working memory of the control processing unit 2 and stores data generated during the execution of the predetermined program. The storage unit 6 may also be configured to include a hard disk device with a relatively large storage capacity.

[0064] The control processing unit 2 is a circuit for controlling each of the components 1, 3, through 6 of the weld line generation device S according to their respective functions. It generates weld lines for the multiple workpieces based on three-dimensional point cloud data of the weld targets arranged in a predetermined space, and also generates teaching data based on the generated weld lines. The control processing unit 2 is configured, for example, to include a CPU (Central Processing Unit) and its peripheral circuits. By executing a control processing program, the control processing unit 2 functionally comprises a control unit 21, an edge extraction unit 22, a workpiece point cloud data generation unit 23, a weld line generation unit 24, and a teaching data generation unit 25.

[0065] The control unit 21 controls each of the components 1 and 3 to 6 of the weld line generating device S according to their functions, and is responsible for overall control of the weld line generating device S. The control unit 21 stores the three-dimensional point cloud data acquired by the point cloud data acquiring unit 1 in the storage unit 6 .

[0066] The edge extraction unit 22 extracts edges from the three-dimensional point cloud data acquired by the point cloud data acquisition unit 1. More specifically, the edge extraction unit 22 first pre-processes the three-dimensional point cloud data acquired by the point cloud data acquisition unit 1 to remove noise and outliers using conventional methods such as a smoothing filter. The edge extraction unit 22 then extracts edges from the pre-processed three-dimensional point cloud data using conventional methods. This edge extraction process is disclosed, for example, in "D. Bazazian, JR Casas and J. Ruiz-Hidalgo, 'Fastand Robust Edge Extraction in Unorganized Point Clouds,' 2015 International Conference on Digital Image Computing: Techniques and Applications (DICTA), 2015, pp. 1-8, doi: 10.1109 / DICTA.2015.7371262." For example, at each point in the point cloud, the normals passing through the point are parallel to each other in a plane, but are intersecting at the edge. Therefore, edges can be detected by evaluating the normal line of each point.

[0067] The workpiece point cloud data generator 23 generates three-dimensional point cloud data for each of the plurality of workpieces based on the three-dimensional point cloud data obtained by the point cloud data acquirer 1 by deleting the edges extracted by the edge extractor 22 .

[0068] For example, when the welding target includes a first workpiece of a rectangular (square) shape set upright, a second workpiece having a bottom plate of the same shape connected to the lower end (lower side) of the first workpiece, and a third workpiece of the same shape connected to the side end (side) of the first workpiece and connected to the end (side) of the second workpiece adjacent to the end (side) connected to the first workpiece, the point cloud data acquisition unit 1 acquires Figure 2 The three-dimensional point cloud data for the first to third workpieces are shown. Figure 2 When the edge extraction unit 22 extracts the edge of the three-dimensional point cloud data shown in FIG. Figure 3As shown, nine edges, EG1 to EG9, are extracted. The first to fourth edges EG1 to EG4 correspond to the four edges of the first workpiece, the fourth to seventh edges correspond to the four edges of the second workpiece, and the seventh to ninth edges, as well as the first edge EG7 to EG9 and EG1, correspond to the four edges of the third workpiece. Of the first to ninth edges EG1 to EG9, edges EG between welded components, such as the first, fourth, and seventh edges EG1, EG4, and EG7, are extracted. Meanwhile, edges EG that are not between welded components, such as the remaining second, third, fifth, sixth, eighth, and ninth edges EG2, EG3, EG5, EG6, EG8, and EG9, are also extracted. Therefore, in this embodiment, the workpiece point cloud data generator 23 deletes the three-dimensional point cloud data of the edges extracted by the edge extraction unit 22 from the three-dimensional point cloud data acquired by the point cloud data acquisition unit 1, and generates three-dimensional point cloud data for each of the multiple workpieces based on the deleted three-dimensional point cloud data. For example, the workpiece point cloud data generator 23 generates three-dimensional point cloud data for each of the multiple workpieces by performing a so-called clustering process on the deleted three-dimensional point cloud data. In the clustering process, for example, K-means, Euclidean Clustering, DBSCAN, etc. are used. In this embodiment, the Euclidean Clustering is used. Figure 2 In the example shown, the generated Figure 4 The three-dimensional point cloud data WK1 to WK3 of the first to third workpieces are shown.

[0069] The welding line generating unit 24 generates welding lines for the plurality of workpieces based on the three-dimensional point cloud data of each of the plurality of workpieces generated by the workpiece point cloud data generating unit 23 .

[0070] More specifically, the distance between each end portion is evaluated based on the three-dimensional point cloud data of each of the plurality of workpieces (in Figure 2In the example shown, the distance between each side is used to search for the ends of adjacent workpieces to be welded, and a weld line is generated between the ends. More specifically, the weld line generation unit 24 performs a determination process on all combinations of two workpieces in the three-dimensional point cloud data for each of the plurality of workpieces generated by the workpiece point cloud data generation unit 23, and generates the weld line between the adjacent ends of the two workpieces determined to be adjacent by the determination process. This determination process selects two workpieces from the three-dimensional point cloud data for each of the plurality of workpieces generated by the workpiece point cloud data generation unit 23, and if a distance between the ends of any of the selected two workpieces is less than a predetermined threshold, the determination is made that the selected two workpieces are adjacent workpieces having adjacent ends. The predetermined threshold is used to determine whether the end distance is the distance between the adjacent ends of the two adjacent workpieces, and is appropriately set in advance based on a plurality of samples.

[0071] For example, in Figure 4 In the example shown, the three-dimensional point cloud data WK1 of the first workpiece and the three-dimensional point cloud data WK2 of the second workpiece are selected from the three-dimensional point cloud data WK1 to WK3 of the first to third workpieces, and it is determined whether there is a distance between the ends of all combinations of the four sides of the first workpiece and the four sides of the second workpiece that is less than the predetermined threshold. The result of this determination is that, in the first workpiece and the second workpiece, Figure 5 As shown, the end spacing BL12 at the lower end of the first workpiece is determined to be the end spacing between the adjacent ends of the two adjacent workpieces, and the first and second workpieces are determined to be adjacent workpieces with adjacent ends. This determination process is performed on both the 3D point cloud data WK2 of the second workpiece and the 3D point cloud data WK3 of the third workpiece, and on the 3D point cloud data WK3 of the third workpiece and the 3D point cloud data WK1 of the first workpiece. As a result, the end spacing BL23 at the lower end of the third workpiece is determined to be the end spacing between the adjacent ends of the two adjacent workpieces, and the second and third workpieces are determined to be adjacent workpieces with adjacent ends. The end spacing BL31 at the side end of the first workpiece is determined to be the end spacing between the adjacent ends of the two adjacent workpieces, and the third workpiece is determined to be adjacent workpieces with adjacent ends. Then, the weld line generating unit 24 generates a weld line between the end portions BL12 , generates a weld line between the end portions BL23 , and generates a weld line between the end portions BL31 .

[0072] More specifically, the weld line generation unit 24 performs a generation process for all of the two workpieces determined to be adjacent to each other by the determination process. The generation process generates candidate weld line points for each of the adjacent end points of the two workpieces determined to be adjacent to each other by the determination process, between the end point of one of the two workpieces and the end point of the other of the two workpieces closest to the end point, and generates a fitting line fitted to each of the generated candidate points as the weld line. The fitting line may be, for example, a straight line, a circular arc, or a curve represented by a high-order polynomial such as a quadratic function.

[0073] For example, in Figure 5 In the example shown, Figure 6 As shown, for each end point P2j, P3k of each adjacent end (each side) EL2, EL3 of the second and third workpieces adjacent to each other at the end BL23, a candidate point MP for a welding line is generated between the end point P2j of the end EL2 of one of the second and third workpieces and the end point P3k of the end EL3 of the other of the second and third workpieces closest to the end point P2j. Figure 6 In the process, a candidate point MP for the weld line is generated at, for example, the center position (midpoint) between the end point P2 of the second workpiece end EL2 and the end point P3 of the third workpiece end EL3 closest to the end point P2. This process is performed on each end point P2j of the second workpiece end EL2, generating a plurality of candidate points MP between the end portions BL23. Figure 7 As shown, a fitting line WL23 fitted to each of the candidate points MP is generated as the weld line WL23. The same process is performed for the first and second workpieces adjacent to each other at end portion BL12. Multiple candidate points MP are generated between end portions BL12, and weld line WL12 is generated. The same process is performed for the second and third workpieces adjacent to each other at end portion BL23. Multiple candidate points MP are generated between end portions BL31, and weld line WL31 is generated.

[0074] The teaching data generating unit 25 generates teaching data (motion data) for operating the multi-joint robot equipped with a welding torch, based on the welding line generated by the welding line generating unit 24, using conventional methods known in the art. More specifically, in this embodiment, the teaching data generating unit 25 generates teaching data using a welding line selected by an operator (user) from among the welding lines generated by the welding line generating unit 24 and welding conditions specified by the operator. The teaching data generating unit 25 stores the generated teaching data (motion data) in the storage unit 6 and outputs it to the output unit 4 and the input interface unit 5. For example, if the output unit 4 is a display device, the teaching data generating unit 25 displays the welding line generated by the welding line generating unit 24 on the output unit 4. The operator specifies the welding line to be used for the teaching data from among the welding lines displayed on the output unit 4 through an input operation on the input unit 3. The operator also inputs welding conditions, such as the thickness of the workpiece, into the input unit 3. The teaching data generating unit 25 then generates teaching data using the welding line selected by the input unit 3 and the welding conditions input to the input unit 3.

[0075] The control processing unit 2 , the input unit 3 , the output unit 4 , the IF unit 5 , and the storage unit 6 can be configured by, for example, a desktop, notebook, or tablet computer.

[0076] Next, the operation of this embodiment will be described. Figure 8 1 is a flowchart showing the operation of the weld line generating device.

[0077] When powered on, the weld line generation device S with this configuration initializes all necessary components and begins operation. The control processing unit 2, through the execution of its control processing program, functionally comprises a control unit 21, an edge extraction unit 22, a workpiece point cloud data generation unit 23, a weld line generation unit 24, and a teaching data generation unit 25.

[0078] For example, when an operator (user) inputs a command to start welding line generation into the input unit 3, Figure 8 In the present invention, first, the weld line generation device S uses the point cloud data acquisition unit 1 to acquire three-dimensional point cloud data of a plurality of workpieces to be welded arranged in a predetermined space, and stores the data in the storage unit 6 ( S1 ).

[0079] Next, the weld line generating device S performs pre-processing on the three-dimensional point cloud data acquired by the point cloud data acquiring unit 1 using the edge extraction unit 22 of the control processing unit 2 ( S2 ).

[0080] Next, the weld line generation device S uses the edge extraction unit 22 of the control processing unit 2 to extract edges from the pre-processed three-dimensional point cloud data. The workpiece point cloud data generation unit 23 of the control processing unit 2 generates three-dimensional point cloud data for each of the plurality of workpieces based on the three-dimensional point cloud data obtained by the point cloud data acquisition unit 1 in step S1 by deleting the three-dimensional point cloud data of the edges extracted by the edge extraction unit 22 (S3).

[0081] Next, the weld line generating device S generates weld lines for the plurality of workpieces based on the three-dimensional point cloud data of each of the plurality of workpieces generated by the workpiece point cloud data generating unit 23 in step S3 by using the weld line generating unit 24 of the control processing unit 2 ( S4 ).

[0082] Next, the weld line generation device S receives the selection of a weld line for teaching data via the teaching data generation unit 25 of the control processing unit 2 (S5). More specifically, in this embodiment, the teaching data generation unit 25 displays the weld line generated by the weld line generation unit 24 on the output unit 4 through processing S4. The operator specifies the weld line for teaching data from among the weld lines displayed on the output unit 4 through an input operation on the input unit 3. The teaching data generation unit 25 stores the weld line specified by the input unit 3 as the weld line for teaching data in the storage unit 6.

[0083] Next, the weld line generation device S receives input of welding conditions for the teaching data using the teaching data generation unit 25 (S6). More specifically, in this embodiment, the operator inputs welding conditions, such as the workpiece thickness, into the input unit 3 following the weld line designation. The teaching data generation unit 25 stores the welding conditions input to the input unit 3 as the teaching data in the storage unit 6.

[0084] Next, the welding line generation device S generates teaching data using the welding line specified by the input unit 3 in process S5 and the welding conditions input to the input unit 3 in process S6 by the teaching data generation unit 25. The generated teaching data (operation data) is stored in the storage unit 6 and output to the output unit 4 and the IF unit 5, and this process ends (S7).

[0085] As described above, the weld line generation device S of the embodiment, and the weld line generation method and weld line generation program installed in the weld line generation device S generate weld lines based on three-dimensional point cloud data of a plurality of workpieces to be welded. Therefore, weld lines can be automatically generated without the need for three-dimensional CAD data.

[0086] The weld line generation device S, weld line generation method, and weld line generation program described above can identify two adjacent workpieces having adjacent ends and automatically generate a weld line.

[0087] The weld line generation device S, weld line generation method, and weld line generation program described above can generate a weld line using a fitting line fitted to each candidate point.

[0088] It should be noted that in the above-described embodiment, when the fitted line has an inflection point, the weld line generator 24 groups the candidate points for generating the fitted line with the inflection point as the boundary, and generates a weld line for each group using a fitted straight line fitted to each candidate point. Such a weld line generator S, weld line generation method, and weld line generation program divide the weld line of the fitted line at the inflection point and regenerate it into multiple weld lines, thereby generating a more appropriate weld line that corresponds to the shape of the workpiece end.

[0089] Furthermore, in the above-described embodiment, the weld line to be actually used as the weld line is designated and selected from among the weld lines generated by the weld line generating unit 24 . However, a function to assist in this selection may be provided.

[0090] For example, the welding line generating device S is Figure 1 As indicated by the dotted line in the figure, a first weld line exclusion portion 26 may be further included for excluding short weld lines having a value less than or equal to a predetermined second threshold value from the weld lines generated by the weld line generating portion 24. In this case, the second threshold value may be appropriately set in advance, or input by an operator through the input portion 3, for example. The weld line exclusion portion 26 may use the set second threshold value, or may use the second threshold value received from the input portion 3. Such a weld line generating device S, weld line generating method, and weld line generating program further include the first weld line exclusion portion 26, thereby being able to exclude weld lines that are unlikely to be used for actual welding.

[0091] For example, the welding line generating device S is as shown in Figure 1 As indicated by the dotted line in the figure, a second weld line exclusion portion 27 may be further provided for excluding weld lines outside a predetermined range from weld lines generated by the weld line generating portion 24. In this case, the range may be input by an operator through the input portion 3, for example, and the weld line exclusion portion 26 may use the range received by the input portion 3. Such a weld line generating device S, weld line generating method, and weld line generating program further include the weld line exclusion portion 26, thereby being able to exclude weld lines that are unlikely to be used for welding.

[0092] For example, the welding line generating device S is as follows Figure 1As indicated by the dotted line in FIG. 2 , the apparatus may further include a weld line merging unit 28. When the distance between the first endpoint of one weld line and the second endpoint of the other weld line generated by the weld line generating unit 24 is less than or equal to a predetermined third threshold, the weld line merging unit 28 merges the weld line into a single weld line by connecting the weld line and the other weld line. In this case, the third threshold can be appropriately set in advance or input by an operator through the input unit 3. The weld line merging unit 28 can use the set third threshold or the third threshold received from the input unit 3. Such a weld line generating device S, weld line generating method, and weld line generating program further include the weld line merging unit 28, thereby enabling the generation of more appropriate weld lines.

[0093] In order to express the present invention, the present invention has been appropriately and fully described above through the embodiments with reference to the accompanying drawings. However, those skilled in the art will recognize that the above embodiments can be easily modified and / or improved. Therefore, as long as the modifications or improvements implemented by those skilled in the art do not depart from the scope of the rights of the technical solution described in the scope of the claims, such modifications or improvements shall be interpreted as being included in the scope of the rights of the technical solution.

Claims

1. A welding line generating device, wherein: The welding line generating device comprises: a point cloud data acquisition unit that acquires three-dimensional point cloud data of a plurality of workpieces to be welded arranged in a predetermined space; an edge extraction unit that extracts three-dimensional point cloud data of edges from the three-dimensional point cloud data acquired by the point cloud data acquisition unit; a workpiece point cloud data generating unit that generates three-dimensional point cloud data for each of the plurality of workpieces based on the three-dimensional point cloud data obtained by deleting the three-dimensional point cloud data of the edges extracted by the edge extraction unit from the three-dimensional point cloud data obtained by the point cloud data acquiring unit; as well as A welding line generating unit generates welding lines for the plurality of workpieces based on the three-dimensional point cloud data of each of the plurality of workpieces generated by the workpiece point cloud data generating unit.

2. The welding line generating device according to claim 1, wherein: The weld line generation unit performs determination processing on all combinations of two workpieces in the three-dimensional point cloud data of each of the plurality of workpieces generated by the workpiece point cloud data generation unit. The determination process is as follows: selecting three-dimensional point cloud data of two workpieces from the three-dimensional point cloud data of each of the plurality of workpieces generated by the workpiece point cloud data generating unit, and determining that the two selected workpieces are adjacent workpieces having adjacent ends when a distance between any of the ends of the two selected workpieces is less than a predetermined threshold value; The weld line generating unit generates the weld line between adjacent end portions of the two workpieces determined to be adjacent to each other by the determination process.

3. The welding line generating device according to claim 2, wherein: The weld line generating unit performs a generating process on all of the two workpieces adjacent to each other determined by the determining process. The generation process is a process in which, for each endpoint of each adjacent end portion of the two workpieces determined to be adjacent to each other by the determination process, candidate points for a welding line are generated between the endpoint of the end portion of one of the two workpieces and the endpoint of the end portion of the other of the two workpieces closest to the endpoint, and a fitting line fitted to each of the generated candidate points is generated as the welding line.

4. The welding line generating device according to claim 3, wherein: When the fitting line has an inflection point, the weld line generating unit groups candidate points for generating the fitting line with the inflection point as a boundary, and generates a fitting straight line fitted to each candidate point as the weld line for each group.

5. The welding line generating device according to claim 1 or 2, wherein: The weld line generating device further includes a weld line excluding portion for excluding short weld lines having a value less than or equal to a predetermined second threshold value from the weld lines generated by the weld line generating unit.

6. The welding line generating device according to claim 1 or 2, wherein: The weld line generating device further includes a second weld line excluding portion for excluding weld lines existing outside a predetermined range from the weld lines generated by the weld line generating unit.

7. The welding line generating device according to claim 1 or 2, wherein: The weld line generating device further includes a weld line merging unit configured to merge the weld lines generated by the weld line generating unit into a single weld line by connecting the weld line to the weld line generated by the weld line generating unit when a distance between a first end point of one weld line and a second end point of the other weld line is equal to or smaller than a predetermined third threshold value.

8. A method for generating a welding line, wherein: The welding line generation method comprises: A point cloud data acquisition step of acquiring three-dimensional point cloud data of a plurality of workpieces to be welded arranged in a predetermined space; an edge extraction step of extracting three-dimensional point cloud data of edges from the three-dimensional point cloud data acquired in the point cloud data acquisition step; a workpiece point cloud data generating step of generating three-dimensional point cloud data of each of the plurality of workpieces based on the three-dimensional point cloud data obtained by the point cloud data acquiring step by deleting the three-dimensional point cloud data of the edges extracted by the edge extraction step; and The welding line generating step generates welding lines for the plurality of workpieces based on the three-dimensional point cloud data of each of the plurality of workpieces generated in the workpiece point cloud data generating step.

9. A recording medium storing a welding line generation program, wherein: The welding line generation program is used to enable the computer to execute the following steps: A point cloud data acquisition step of acquiring three-dimensional point cloud data of a plurality of workpieces to be welded arranged in a predetermined space; an edge extraction step of extracting three-dimensional point cloud data of edges from the three-dimensional point cloud data acquired in the point cloud data acquisition step; a workpiece point cloud data generating step for generating three-dimensional point cloud data of each of the plurality of workpieces based on the three-dimensional point cloud data obtained by the point cloud data acquiring step by deleting the three-dimensional point cloud data of the edge extracted by the edge extraction step; as well as The welding line generating step generates welding lines for the plurality of workpieces based on the three-dimensional point cloud data of each of the plurality of workpieces generated in the workpiece point cloud data generating step.

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