Method for correcting operation program, welding system, and program

Abstract

To provide a method for correcting an operation program of a welding robot, by which reduction of manual work time and work simplification can be achieved.SOLUTION: A method for correcting an operation program of a welding robot includes: acquiring a first image in which a member to be welded is not placed, and a second image in which the member to be welded is placed, the images being captured by an imaging apparatus from a predetermined direction; comparing the first image with the second image to specify a region corresponding to the member to be welded in the second image; aligning the specified region with a shape of three-dimensional CAD data corresponding to the member to be welded, in a direction corresponding to the predetermined direction, at two or more points, to identify a position of the member to be welded; and correcting coordinate information to be used for an operation program for actuating the welding robot on the basis of the identified position.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present invention relates to a method for correcting an operation program, a welding system, and a program.

Background Art

[0002] Currently, robots are used in various industrial fields. A typical industrial robot is a welding robot. In welding work, the welding robot is operated using an operation program in which optimal welding conditions are set according to each construction condition. In setting such construction conditions and welding conditions, there are a number of elements, parameters, and combinations thereof.

[0003] The operation program of the welding robot is set on the premise that the welded member to be welded is positioned at a predetermined position. However, in actual welding work, the position of the welded member is not necessarily arranged at the predetermined position as described above. When the welded member is displaced from the predetermined position, it may cause problems in the welding work or lead to a deterioration in the quality of the welded product.

[0004] For example, in Patent Document 1, a method is described in which, according to the actual arrangement position of the welded member, the 3D CAD data is associated with the image inner vertices obtained from the image data of the welded member to obtain a difference, and the operation program of the welding robot is corrected based on the difference.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] In the method of Patent Document 1, image data is acquired after positioning the target welded member so that it can be imaged by a sensor. In an actual welding construction site, the construction site is large and numerous welded members are arranged. Therefore, it is necessary to position the camera provided in the welding robot so that a desired image of each welded member can be obtained and perform imaging. Such work for specifying the position of an actual welded member requires manual labor and time, resulting in a high work load. As a result, when correcting the operation program corresponding to the position of the actually installed welded member, the work load has been high. Therefore, at a welding construction site, there is a demand for shortening the manual work time and simplifying the work such as correcting the operation program.

[0007] In view of the above problems, an object of the present invention is to provide a method for correcting an operation program of a welding robot that can shorten the manual work time and simplify the work.

Means for Solving the Problems

[0008] In order to solve the above problems, one embodiment of the present invention has the following configuration. That is, the method for correcting the operation program of a welding robot is as follows. An acquisition step of acquiring a first image in a state where the welded member is not installed and a second image in a state where the welded member is installed, which are photographed by an imaging device from a predetermined direction; A first specifying step of specifying a region corresponding to the welded member in the second image by comparing the first image and the second image; A second specifying step of specifying the position of the welded member by aligning at least two points between the region specified in the first specifying step and the shape of the three-dimensional CAD data corresponding to the welded member in the direction corresponding to the predetermined direction; A correction step of correcting the coordinate information used in the operation program for operating the welding robot based on the position specified in the second specifying step. An operation program correction method characterized by comprising the above steps.

[0009] Also, in another aspect of the present invention, it has the following configuration. That is, the welding system includes a welding robot, an imaging device, and a control unit that corrects an operation program using a method for correcting the operation program and controls the welding robot. The correction method includes: an acquisition step of acquiring a first image in a state where the welded member is not installed and a second image in a state where the welded member is installed, both images being taken by the imaging device from a predetermined direction; a first identification step of identifying a region corresponding to the welded member in the second image by comparing the first image and the second image; a second identification step of identifying the position of the welded member by aligning at least two points between the region identified in the first identification step and the shape of the three-dimensional CAD data corresponding to the welded member in the direction corresponding to the predetermined direction; and a correction step of correcting coordinate information used in an operation program for operating the welding robot based on the position identified in the second identification step. Also, in another aspect of the present invention, it has the following configuration. That is, the program causes a computer to perform an acquisition step of acquiring a first image in a state where the welded member is not installed and a second image in a state where the welded member is installed, both images being taken by the imaging device from a predetermined direction;

[0010] a first identification step of identifying a region corresponding to the welded member in the second image by comparing the first image and the second image; a second identification step of identifying the position of the welded member by aligning at least two points between the region identified in the first identification step and the shape of the three-dimensional CAD data corresponding to the welded member in the direction corresponding to the predetermined direction; a correction step of correcting coordinate information used in an operation program for operating the welding robot based on the position identified in the second identification step. a first identification step of identifying a region corresponding to the welded member in the second image by comparing the first image and the second image; a second identification step of identifying the position of the welded member by aligning at least two points between the region identified in the first identification step and the shape of the three-dimensional CAD data corresponding to the welded member in the direction corresponding to the predetermined direction; A correction step of correcting coordinate information used in an operation program for operating a welding robot based on the position specified in the second specifying step; to cause to execute

Advantages of the Invention

[0011] According to the present invention, it is possible to shorten the man-hours and simplify the work related to the setting of the operation program of the welding robot at the actual welding work site.

Brief Description of the Drawings

[0012]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Mode for Carrying Out the Invention

[0013] Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings and the like. Note that the embodiments described below are merely examples for explaining the present invention, and are not intended to be construed as limiting the present invention. Also, not all the configurations described in each embodiment are essential for solving the problems of the present invention.

[0014] [System Configuration] Figures 1 and 2 are schematic diagrams showing a configuration example of the welding system 100 according to this embodiment. In each figure, the correspondence in the three-dimensional space is shown by the three axes of X, Y, and Z. For example, in Figure 1, the X-axis indicates the depth direction, the Y-axis indicates the width direction, and the Z-axis indicates the height direction. However, the correspondence of each axis is an example, and other correspondences may be used.

[0015] As shown in Figure 1, the welding system 100 includes a portal-shaped support frame 10, a carriage unit 20, a guide rail 30, a movable unit 40, a welding robot 50, a camera 60, and a control device 70.

[0016] The support frame 10 includes a plurality of columns 11 erected along the Z-axis direction and a guide support beam 12 provided along the Y-axis direction. The plurality of columns 11 are provided on the carriage unit 20. The carriage unit 20 is configured to be able to reciprocate along the X-axis direction on a guide rail 30 provided along the X-axis direction. Thereby, the support frame 10 is enabled to reciprocate on the guide rail 30. The guide rail 30 is installed outside the installation area 200 where the welded member W to be welded is arranged.

[0017] The movable unit 40 includes a slider 41, a shaft portion 42, and a swivel frame 43. The slider 41 is supported by the guide support beam 12 so as to be able to reciprocate along the Y-axis direction. A shaft portion 42 serving as a rotation axis is attached to the lower part of the slider 41, and a swivel frame 43 that swivels around the center of the shaft portion 42 is horizontally attached to the protruding end from the shaft portion 42.

[0018] The camera 60 is a sensor that images the welded member W and is provided below the movable part 40. The camera 60 images the welded member W actually arranged in the installation area 200 to acquire an image of the welded member W. The camera 60 is constituted by, for example, a CCD (Charge Coupled Device) camera. Note that the attachment position of the camera 60 shown in FIG. 1 is an example and is not limited thereto. Further, the camera 60 may be provided with various lenses such as a fish-eye lens and a zoom lens. Also, there may be a plurality of cameras 60. When a plurality of cameras 60 are provided, the plurality of cameras 60 may be configured to be able to photograph different positions, or may be configured to be able to photograph under different photographing conditions and the like. Further, the welding system 100 may be further provided with an illumination unit used when photographing by the camera 60.

[0019] On the lower surface of the tip of the swivel frame 43, a welding robot 50 is attached so as to be rotatable around a vertical axis. A welding torch 51 is attached to the tip of the welding robot 50. In the present embodiment, a configuration example of a twin welding robot device to which two welding robots 50 are attached is shown. In the present embodiment, the welding robot 50 is an arc welding robot having a torch at its tip and is configured to enable touch sensing. Note that the type and number of the welding robots 50 are not particularly limited, and different welding robots according to the welded member W may be used.

[0020] Also, a wire pack for storing the welding wire may be mounted above the movable part 40, or a wire feeding device for supplying the welding wire to another location may be provided. The welding wire is fed out from the tip of the welding torch toward the welding location of the welded member W.

[0021] Below the welding robot 50, an installation area 200 is located, and a welded member W to be welded by the welding robot 50 is arranged. The welded member W is arranged in the installation area 200 by an operator or the like in a timely manner. A plurality of welded members W are welded by the welding robot 50. At this time, the welding robot 50 can move to a position directly above or around the target welded member W by moving in the X-axis direction of the carriage unit 20 and moving in the Y-axis direction of the movable unit 40. The welded member W is various metal members, and a desired position is welded by the welding robot 50. Depending on the material of the welded member W and the like, the material of the welding wire used for welding may also be different.

[0022] The control device 70 operates as a computer for controlling the operation of the welding robot 50, and includes a control unit 71, a storage unit 72, and a robot pendant 73 used as a teaching pendant. The control unit 71 is constituted by, for example, a CPU (Central Processing Unit). The storage unit 72 is constituted by, for example, a volatile or non-volatile memory such as an HDD (Hard Disk Drive), a ROM (Read Only Memory), or a RAM (Random Access Memory). By the control unit 71 reading out and executing a control computer program stored in the storage unit 72, various operations related to welding are controlled, or processes such as image processing described later are executed.

[0023] The control device 70 acquires welding path information regarding the construction conditions of a welding path for welding two workpieces to be welded. The control device 70 executes the acquisition of this welding path information according to a predetermined program, and outputs an operation instruction to the welding robot 50, that is, the acquired welding path according to a previously taught program (hereinafter also referred to as a teaching program). In particular, the control device 70 stores in the storage unit 72 a database of 3D CAD (Computer-Aided Design) data, which is the design data of the workpiece W, and refers to this 3D CAD data when controlling the operations of the welding robot 50 and the like. The database of 3D CAD data may be constructed by a server or the like connected to the control device 70 via a network (not shown), and the location, format, configuration, etc. of the database are not particularly limited.

[0024] Although not shown in FIG. 1, the welding system 100 is further provided with a power supply device for supplying power to the welding wire. In addition, sensors for detecting voltage and current may be provided. Further, each part constituting the welding system 100 may be communicably connected by various wired / wireless communication methods. Also, the welding system 100 may be communicably connected to an external device via a network. The communication method here is not limited to one, and a plurality of communication methods may be combined and connected.

[0025] FIG. 2 is an external perspective view of a configuration example of the welding system 100 according to the present embodiment. As described with reference to FIG. 1, the welding system 100 is configured to be movable above an installation area 200 where one or more workpieces W are installed. Thereby, the camera 60 can also take pictures at various positions while moving above the installation area 200. Although an operator and the workpiece W are shown as examples in FIG. 2, the dimensions of each component etc. are examples and are not limited thereto.

[0026] [Functional Configuration] FIG. 3 is a block diagram showing an example of the functional configuration of the control device 70 according to the present embodiment. For example, the control unit 71 of the control device 70 is realized as a part that provides each function shown in FIG. 3 by reading and executing various programs stored in the storage unit 72. Note that FIG. 3 shows a configuration example focusing on the functions according to the present embodiment, and may further include more parts. Also, each part may be further divided or combined according to the function.

[0027] The control device 70 includes an operation program management unit 301, an image acquisition unit 302, an image analysis unit 303, a 3D CAD data management unit 304, an operation program correction unit 305, and a welding robot control unit 306. The operation program management unit 301 holds and manages an operation program used to operate the welding robot 50. The operation program may be configured to be acquired from an external device, or may be input by an operator as a teaching program via the robot pendant 73. The operation program may include, in addition to instructions regarding the operation pattern of the welding robot 50, welding path information such as the position of the welding path and welding conditions for the welded member W, and information such as the installation position in the installation area 200 of the welded member W. The operation program is stored in the storage unit 72 and managed by the operation program management unit 301.

[0028] The image acquisition unit 302 acquires one or more images of the installation area 200 captured by the camera 60. When the image acquisition unit 302 acquires one or more images, it also acquires information on the shooting position and shooting parameters. As described above, the welding robot 50 can perform shooting of at least the range where the welding operation is performed in the installation area 200 while changing its shooting position. The image analysis unit 303 analyzes the one or more images acquired by the image acquisition unit 302. Details of the image analysis process according to the present embodiment will be described later.

[0029] The 3D CAD data management unit 304 holds and manages 3D CAD data indicating the three-dimensional shape of the welded member W. The 3D CAD data here may include, in addition to the three-dimensional shape of each welded member W, the state during the welding process, that is, CAD data indicating the state before completion in which a plurality of welded members are joined by welding to form one welded member. Further, although details will be described later, the 3D CAD data includes information on the installation orientation of the object corresponding to the welded member, that is, the direction in which the camera 60 takes a picture. In the present embodiment, the photographing by the camera 60 will be described as being performed along the upper side, that is, the height direction, but it is not limited thereto. If the correspondence relationship with the 3D CAD data described later is defined in advance, for example, the photographing may be performed along the width direction or the depth direction.

[0030] Based on the analysis result by the image analysis unit 303, the operation program correction unit 305 corrects the parameters specified in the operation program. The welding robot control unit 306 controls the operation of the welding robot 50 using the operation program managed by the operation program management unit 301 or the operation program corrected by the operation program correction unit 305.

[0031] [Processing Flow] FIG. 4 is a flowchart of the processing according to the present embodiment. This processing may be realized, for example, by the control unit 71 provided in the control device 70 reading out a program for realizing each part from the storage unit 72 and executing it. Here, for simplicity of explanation, the processing subject will be collectively described as the control device 70. Further, when this processing flow is started, it is assumed that one or more welded members W are already installed in the installation area 200. Further, it is assumed that 3D CAD data and an operation program corresponding to the welded member W are registered.

[0032] In S401, the control device 70 refers to the storage unit 72 and acquires image data of the installation area 200 in a state where the welded member W is not installed. Prior to executing this process, it is assumed that the image data generated by photographing the installation area 200 in a state where the welded member W is not installed is held in the storage unit 72. This image data is referred to as "image data without installation" or "first image". The image data without installation may be acquired by performing the same operations (S402 and S403) as those for acquiring the "image data with installation" described later. If the time and effort required for installing the welded member W in the installation area 200 are minor, it is not necessary to pre-hold the image data without installation in the storage unit 72. Instead of this step, a photographing step for photographing the image data without installation may be provided. Also, assuming changes over time and deterioration over time in the installation area 200, the installation area 200 in a state where the welded member W is not installed may be periodically photographed so that the image data without installation held in the storage unit 72 is periodically updated.

[0033] In S402, the control device 70 drives the carriage unit 20 and the movable unit 40, photographs the installation area 200 while adjusting the photographing position of the camera 60, and acquires one or more pieces of image data. The photographing range here may be limited to a preset range within the installation area 200, or may be configured to photograph the entire installation area 200. Photographing parameters including the photographing range and photographing order at this time may be defined in advance, or may be specified by the operator. At this time, the position information at the time of photographing by the camera 60 is acquired in association with the image data. The position information of the camera 60 may be derived based on the position information of the carriage unit 20 and the movable unit 40.

[0034] In S403, the control device 70 synthesizes the one or more pieces of image data acquired in S402 based on the position information to generate one piece of image data indicating an image of the installation area 200. Hereinafter, the image data generated here is referred to as "image data with installation" or "second image". The method of synthesizing a plurality of pieces of image data into one piece of image data is not particularly limited. For example, it may be a method of extracting a predetermined range from each image and synthesizing while overlapping adjacent image data based on the position information. The predetermined range here may be, for example, a range with less distortion and the like caused by the shooting parameters of the camera 60 and the device characteristics in the image data.

[0035] In S404, the control device 70 extracts the region of the welded member W included in the image data with installation generated in S403 using the image data without installation acquired from the storage unit 72 in S401.

[0036] The processing in this step will be described with reference to FIG. 5. In FIG. 5, the image data with installation 500 and the image data without installation 510 are shown as an example, and the transition of the image is shown by the processing.

[0037] First, the control device 70 performs alignment between the image data without installation acquired from the storage unit 72 in S401 and the image data with installation generated in S403, extracts the difference, and generates a difference image. The alignment here may be performed, for example, by extracting feature points commonly included in each image data and based on this, or may be performed based on the position information acquired during shooting. The difference image 520 in FIG. 5 shows the difference between the image data with installation 500 and the image data without installation 510. Here, the difference image 520 is shown as a binary image, where white pixels indicate the difference and black pixels indicate the common parts.

[0038] Furthermore, the control device 70 extracts one or more candidate regions indicating the welded member W included in the difference image. The candidate regions here may be extracted based on, for example, shape, position, size, the number of pixels in the image, etc., but are not particularly limited. For example, three-dimensional CAD data of one or more welded members W assumed to be installed in the installation region 200 may be acquired, and one or more candidate regions may be extracted based on that information. Also, a configuration may be adopted in which image processing such as noise removal and binarization processing is applied to the difference image to improve the extraction accuracy. The image 530 in FIG. 5 shows an example in which two candidate regions 531 and 532 are extracted after performing image processing on the difference image 520.

[0039] Furthermore, the control device 70 specifies one region of interest (hereinafter also referred to as the region of interest) from among the one or more candidate regions. The specification method here may be specified based on, for example, shape, position, size, etc., but is not particularly limited. For example, three-dimensional CAD data of the welded member W assumed to be installed in the installation region 200 may be acquired, and based on that information, one region may be narrowed down from among the one or more candidate regions, or the operator's designation may be accepted. The image 540 in FIG. 5 shows a state in which one region 541 is specified as the region of interest from the image 530 and the other regions are filled with black pixels.

[0040] In S405, the control device 70 derives the position and rotation angle of the region of interest specified in S404. The position here may be the coordinate value in the absolute coordinate system preset with respect to the installation region 200. Also, the rotation angle may be the rotation angle based on a predetermined axis of the absolute coordinate system preset with respect to the installation region 200 and a predetermined reference point.

[0041] Regarding the processing in this project, it will be described with reference to FIGS. 6 and 7. In FIG. 6, an image 600 is shown as an example, and the transition of the image is shown by the processing. Note that the image 600 corresponds to the example shown as the image 540 in FIG. 5. In the image 600, first, the coordinates of the rotation reference point 601 are specified. For example, the reference point 601 may use the center coordinates in the X-axis direction and the Y-axis direction of the target area, but it is not particularly limited. Also, the coordinates of the reference point 601 may be specified in the absolute coordinate system set in advance for the installation area 200, or may be shown in the relative coordinate system from an arbitrary position. Then, the rotation angle of the target area is specified with respect to the reference point 601. For example, by focusing on an arbitrary side that constitutes the target area, the inclination of the side with respect to the X-axis direction or the Y-axis direction may be specified as the rotation angle indicating the inclination of the target area. The arbitrary side here may be the longest side that constitutes the target area, or may be specified by the operator.

[0042] Next, the control device 70 acquires the 3D CAD data of the welded member W corresponding to the target area. This may be specified by the operator, or one 3D CAD data may be specified in the processing so far. When the control device 70 specifies one 3D CAD data corresponding to the target area, for example, it may be specified from the registered 3D CAD data based on the size and shape of the target area.

[0043] Next, based on the derived reference point and rotation angle, the control device 70 generates an image corresponding to the target area from the 3D CAD data of the corresponding welded member W. The generation method here will be further described with reference to FIG. 7. In this example, it is assumed that the 3D CAD data 610 in FIG. 6 corresponds to the area specified in the image 600. In the present embodiment, the surface of the welded member W installed in the installation area 200, which is a planar area, is specified. Therefore, as shown in FIG. 7, the orientation captured by the camera 60 is uniquely specified. Thus, the 3D CAD data is rotated according to that orientation. In other words, the 3D CAD data is rotated so that the welded member W installed in the installation area 200 is viewed from directly above. As a result, an image 700 is obtained. Further, the image is rotated based on the derived reference point and rotation angle. As a result, an image 710 is obtained. Furthermore, based on the size and shooting parameters of the image 600, etc., by adjusting the size of the image 710, an image 620 as shown in FIGS. 6 and 7 is generated.

[0044] Next, the control device 70 determines an arbitrary plurality of feature points in the image 620. In FIG. 6, an example is shown where two vertices 621 and 622 on the diagonal of the area are determined as feature points. Note that the method for determining the feature points is not particularly limited, and any location such as the corners, boundaries, or sides of the area may be determined as a feature point and used. Alternatively, the feature points may be registered in advance in the 3D CAD data.

[0045] Next, the control device 70 aligns the installation image data 500, which is the original image data generated in S403 of FIG. 4, with the image of the welded member W generated from the 3D CAD data to generate a composite image. The composite image 630 in FIG. 6 shows an example of a composite image generated by performing alignment based on the vertices 621 and 622. In the composite image 630, the vertices 631 and 632 are the vertices of the welded member W obtained by performing alignment and image composition. Thereby, the correspondence between the 3D CAD data and the image obtained by shooting, that is, the coordinate alignment can be performed.

[0046] Return to the flowchart of FIG. 4. At S406, the control device 70 acquires an operation program for the welding member W of interest. At this time, welding path information is associated with the operation program. Then, the coordinates specified in the operation program are corrected based on the coordinates specified at S405. As described above, since the 3D CAD data and the welding member W in the real space are associated with each other, the coordinates of the welding path to be welded can also be specified, so it is possible to correct the control parameters of the operation program that has already been set accordingly.

[0047] The correction here may be performed, for example, so as to be within the range that can be sensed during welding. For example, the distance during touch sensing can be set to 100 mm or less or 50 mm or less. The sensing operation is performed, for example, by detecting contact with the welding member W by a contact sensor provided at the tip of the welding robot 50. The range within which sensing is possible may be defined in advance and held in the storage unit 72 or the like. The method of sensing by a contact sensor or the like is not particularly limited, and examples include methods such as a contact probe sensor and a wire touch sensor. When the welding member W is installed at a position already defined in the operation program or within the range where sensing is possible, the operation program does not need to be corrected. Also, in the correction, in addition to the correction of the coordinates, other control parameters may be adjusted together.

[0048] That is, even if the error between the position of the welding member W in the real space and the position of the welding member W specified from the image does not exactly match, since this error is included in the range detectable by the sensing function, it is possible to appropriately correct the control parameters of the operation program. As a result, the system automatically adjusts the parameters, enabling higher-precision welding.

[0049] As described above, according to the present embodiment, it is possible to shorten the working time of the work related to setting the operation program of the welding robot and simplify the manual work at the actual welding construction site. In particular, it is no longer necessary to manually repeat the imaging operation by setting the imaging conditions for each of the plurality of members to be welded actually installed in the installation area. Then, using the captured image data, it is possible to correct the operation program with the position information and the like set in advance corresponding to the installation coordinates of the actual member to be welded. Therefore, it is no longer necessary for the operator to individually adjust the parameters related to the position coordinates, and it is possible to reduce the working time.

[0050] <Other Embodiments> In the above embodiment, an example in which the member W to be welded is directly installed in the installation area 200 is shown. On the other hand, when the member W to be welded is installed in the installation area 200, depending on the shape and welding location of the member W to be welded, etc., it may be installed on another member. In that case, compared with the case where the member W to be welded is directly installed in the installation area 200, the height of the member W to be welded can change from the value of the height shown in the 3D CAD data. In that case, the height from the installation area 200 may be specified according to the magnification / reduction ratio between the target area extracted from the captured image and the 3D CAD data. More specifically, when the target area is larger, it is located closer to the camera 60, for example, and has a higher coordinate value in the height direction. The conversion process of the coordinates in the height direction corresponding to this ratio may be performed based on, for example, a predefined table or conversion formula.

[0051] In the present invention, a program or application for realizing the functions of the above-described one or more embodiments can also be realized by supplying it to a system or device using a network or a storage medium, etc., and having one or more processors in the computer of the system or device read and execute the program.

[0052] Alternatively, it may be implemented by a circuit that realizes one or more functions. Examples of the circuit that realizes one or more functions include, for example, an ASIC (Application Specific Integrated Circuit) and an FPGA (Field Programmable Gate Array).

[0053] As described above, the following matters are disclosed in this specification. (1) A method for correcting an operation program of a welding robot, an acquisition step of acquiring a first image in a state where the welded member is not installed and a second image in a state where the welded member is installed, taken by an imaging device from a predetermined direction; a first specifying step of specifying a region corresponding to the welded member in the second image by comparing the first image and the second image; a second specifying step of specifying the position of the welded member by aligning the region specified in the first specifying step and the shape of the three-dimensional CAD data corresponding to the welded member in a direction corresponding to the predetermined direction at at least two points; a correction step of correcting coordinate information used in an operation program for operating the welding robot based on the position specified in the second specifying step; An operation program correction method characterized by comprising the above. According to this configuration, it is possible to shorten the working time of the work related to setting the operation program of the welding robot and simplify the manual work at the actual welding construction site. In particular, it is no longer necessary to set the imaging conditions for each of the plurality of welded members actually installed in the installation area and repeat the imaging operation manually. Then, using the captured image data, it is possible to correct the operation program in which the position information and the like are set in advance corresponding to the installation coordinates of the actual welded member. Therefore, it is no longer necessary for the operator to individually adjust the parameters related to the position coordinates and the imaging conditions, and it is possible to reduce the working time.

[0054] In the second specifying step, the position of the member to be welded corresponding to the position of the region specified in the first specifying step is specified such that the error between the position of the region specified in the first specifying step and the position of the member to be welded corresponding to the position is within the range of an allowable error in the sensing operation performed by the welding robot. The method for correcting the operation program according to (1), characterized by this. According to this configuration, by performing alignment so that it is within the allowable range of the sensing operation provided in advance by the welding robot, it becomes possible to automate the correction corresponding to the function of the welding robot. Further, by performing alignment so that it is within the allowable range of the sensing operation provided in advance by the welding robot, it is not necessary to perform alignment more strictly than necessary, so that it is possible to suppress the load of the correction process.

[0055] (3) The at least two points are feature points registered in the 3D CAD data. The method for correcting the operation program according to (1) or (2), characterized by this. According to this configuration, by using the pre-registered feature points, it becomes possible to easily and accurately grasp the position of the member to be welded.

[0056] (4) At least one member to be welded is arranged, The imaging device performs a plurality of shootings while switching the shooting position, In the acquisition step, one image including the whole of the at least one member to be welded is generated by synthesizing a plurality of images obtained by the plurality of shootings. The method for correcting the operation program according to any one of (1) to (3), characterized by this. According to this configuration, when an operator shoots a wide installation location, it becomes unnecessary to perform individual shooting control, and it becomes possible to save labor. Further, regardless of the size of the installation location, it is possible to acquire an image of the member to be welded and specify the position.

[0057] (5) Position information of the positions imaged in each of the plurality of shootings is acquired, In the acquisition step, the plurality of images are synthesized based on the position information. In the first specific step, a comparison between the first image and the second image is performed based on the position information. A method for correcting an operation program according to (4), characterized in that. According to this configuration, it becomes possible to easily obtain a large composite image based on the position information when shooting with a camera.

[0058] (6) In the second specific step, the coordinates in the predetermined direction are specified based on the ratio between the size of the region specified in the first specific step and the size of the three-dimensional CAD data corresponding to the welded member. A method for correcting an operation program according to any one of (1) to (5), characterized in that. According to this configuration, it becomes possible to specify the position of the welded member in the shooting direction according to the ratio between the images, and to correct the coordinates in the shooting direction.

[0059] (7) The predetermined direction is the height direction. A method for correcting an operation program according to any one of (1) to (6), characterized in that. According to this configuration, it becomes possible to correct the coordinates of the operation program for the case where the shooting direction is along the height direction.

[0060] A welding robot, An imaging device, A control unit that corrects an operation program using the method for correcting an operation program according to any one of (1) to (7) and controls the welding robot A welding system comprising. According to this configuration, it becomes possible to shorten the working time of the work related to the setting of the operation program of the welding robot and simplify the manual work at the actual welding construction site. In particular, it becomes unnecessary for the operator to individually adjust the parameters related to the position coordinates and shooting conditions, and it becomes possible to reduce the working time.

[0061] (9) On a computer, An acquisition step of acquiring a first image in a state where the welded member is not installed and a second image in a state where the welded member is installed, taken by an imaging device from a predetermined direction; A first specifying step of specifying a region corresponding to the welded member in the second image by comparing the first image and the second image; A second specifying step of specifying the position of the welded member by aligning the region specified in the first specifying step and the shape of the three-dimensional CAD data corresponding to the welded member in the direction corresponding to the predetermined direction at at least two points; A correction step of correcting coordinate information used in an operation program for operating a welding robot based on the position specified in the second specifying step; A program for causing the above to be executed. According to this configuration, it is possible to shorten the working time of work related to setting the operation program of the welding robot and simplify the work by hand at the actual welding construction site. In particular, it is no longer necessary to manually repeat the imaging operation by setting the imaging conditions for each of the plurality of welded members actually installed in the installation area. And, it is possible to correct the operation program in which the position information and the like are set in advance corresponding to the installation coordinates of the actual welded member using the captured image data. Therefore, it is no longer necessary for the operator to individually adjust the parameters related to the position coordinates and imaging conditions, and it is possible to reduce the working time.

Explanation of Signs

[0062] 10... Support frame 11... Support column 12... Guide support beam 20... Cart part 30... Guide rail 40... Movable part 41... Slider 42... Shaft part 43... Swivel frame 50... Welding robot 51... Welding torch 60... Camera 70... Control device 71... Control unit 72... Memory unit 100... Welding system 200... Installation area 301... Operation program management unit 302... Image acquisition unit 303... Image analysis unit 304... 3D CAD data management unit 305... Operation program correction unit 306... Welding robot control unit

Claims

1. A method for correcting an operation program of a welding robot, comprising: an acquisition step of acquiring a first image of a state in which a welded member is not installed and a second image of a state in which the welded member is installed, the images being taken by an imaging device from a predetermined direction; a first specifying step of specifying a region corresponding to the welded member in the second image by comparing the first image and the second image; a second specifying step of specifying the position of the welded member by aligning at least two points between the region specified in the first specifying step and the shape of the three-dimensional CAD data corresponding to the welded member in the direction corresponding to the predetermined direction; a correction step of correcting coordinate information used in an operation program for operating the welding robot based on the position specified in the second specifying step; In the second specifying step, the coordinates in the predetermined direction are specified based on the ratio between the size of the region specified in the first specifying step and the size of the three-dimensional CAD data corresponding to the welded member. A method for correcting an operation program, characterized by this.

2. A method for correcting an operation program of a welding robot, comprising: an acquisition step of acquiring a first image of a state in which a welded member is not installed and a second image of a state in which the welded member is installed, the images being taken by an imaging device from a predetermined direction; a first specifying step of specifying a region corresponding to the welded member in the second image by comparing the first image and the second image; a second specifying step of specifying the position of the welded member by aligning at least two points between the region specified in the first specifying step and the shape of the three-dimensional CAD data corresponding to the welded member in the direction corresponding to the predetermined direction; a correction step of correcting coordinate information used in an operation program for operating the welding robot based on the position specified in the second specifying step; In the second specifying step, the position of the welded member is specified such that the error between the position of the region specified in the first specifying step and the position of the welded member corresponding to the position is within the range of an allowable error in a sensing operation performed by the welding robot. A method for correcting an operation program, characterized by this.

3. The method for correcting an operation program according to claim 1 or 2, wherein the at least two points are feature points registered in 3D CAD data.

4. At least one welded member is arranged, The imaging device performs imaging a plurality of times while switching the imaging position, In the acquisition step, by synthesizing a plurality of images obtained by the plurality of times of imaging, one image including the whole of the at least one welded member is generated. The method for correcting an operation program according to any one of claims 1 to 3, characterized in that.

5. Position information of the positions imaged in each of the plurality of times of imaging is acquired, In the acquisition step, the plurality of images are synthesized based on the position information, In the first specifying step, the first image and the second image are compared based on the position information. The method for correcting an operation program according to claim 4, characterized in that.

6. In the second specifying step, coordinates in the predetermined direction are specified based on a ratio between the size of the region specified in the first specifying step and the size of the 3D CAD data corresponding to the welded member. The method for correcting an operation program according to claim 2, characterized in that.

7. The predetermined direction is the height direction. The method for correcting an operation program according to any one of claims 1 to 6, characterized in that.

8. A welding robot, An imaging device, A control unit that corrects an operation program using the method for correcting an operation program according to any one of claims 1 to 7 and controls the welding robot A welding system comprising.

9. In a computer, An acquisition step of acquiring a first image in a state where no welded member is installed and a second image in a state where the welded member is installed, which are imaged by an imaging device from a predetermined direction; A first specifying step of specifying a region corresponding to the welded member in the second image by comparing the first image and the second image; A second specifying step of specifying the position of the welded member by aligning the region specified in the first specifying step and the shape of the 3D CAD data corresponding to the welded member in the direction corresponding to the predetermined direction at at least two points. A correction step of correcting coordinate information used in an operation program for operating a welding robot based on the position specified in the second specifying step is executed. In the second specifying step, a program for specifying coordinates in the predetermined direction based on the ratio between the size of the region specified in the first specifying step and the size of the three-dimensional CAD data corresponding to the member to be welded.

10. A computer An acquisition step of acquiring a first image in a state where the member to be welded is not installed and a second image in a state where the member to be welded is installed, which are photographed by an imaging device from a predetermined direction. A first specifying step of specifying a region corresponding to the member to be welded in the second image by comparing the first image and the second image. A second specifying step of specifying the position of the member to be welded by aligning at least two points between the region specified in the first specifying step and the shape of the three-dimensional CAD data corresponding to the member to be welded in the direction corresponding to the predetermined direction. A correction step of correcting coordinate information used in an operation program for operating a welding robot based on the position specified in the second specifying step is executed. In the second specifying step, a program for specifying the position of the member to be welded so that the error between the position of the region specified in the first specifying step and the position of the member to be welded corresponding to the position is within the range of an allowable error in the sensing operation performed by the welding robot.

Images