Welding quality inspection device and welding quality inspection method

Abstract

A welding quality inspection apparatus includes: a welding position calculation section that calculates a first virtual welding position based on an actual welding position of a robot welding gun; a comparison and verification section calculating a first error by comparing the first virtual welding position and the reference welding position, and determining that inspection is required when a magnitude of the first error is within a reference range; a calibration section generating a second virtual welding position based on the first virtual welding position by repeating calibration until it is determined that the ratio of the need to be inspected becomes smaller than a preset criterion when it is determined by the comparison and verification section that the ratio of the need to be inspected becomes the preset criterion or greater; and a compensation section that extracts and compensates a second error between the second dummy welding position and the reference welding position.

Description

Technical Field

[0001] The present disclosure relates to a welding quality inspection device and a welding quality inspection method. More specifically, the present disclosure relates to a welding quality inspection device and a welding quality inspection method capable of inspecting welding position defects and welding omissions. Background Art

[0002] Welding is a matter directly related to vehicle safety issues and requires accurate confirmation procedures. When quality defects such as welding position defects and welding omissions occur, problems directly related to vehicle safety may arise, such as injuries to occupants due to deterioration of vehicle body strength, noise problems during driving, and watertightness problems during heavy rain. Therefore, ensuring the reliability of welding quality is a very important quality factor that vehicle manufacturers must ensure.

[0003] However, there is currently no clear automated inspection method for welding quality in the body factory, so more than 7,500 welding points are checked by manual visual inspection. As a result, vehicles with defective welding quality due to human error may be sold and provided to customers.

[0004] To prevent missed welds, missed weld prevention checks are performed by counting the number of welds performed by the robot. However, it is not possible to confirm whether the welds are performed at the correct locations and whether there are no actual missed welds.

[0005] In the case of visual inspection to prevent welding position defects and omissions, visual inspection equipment must be installed in the body factory to perform the inspection, and it is not applicable if there is no such equipment. In addition, due to the nature of the production line / equipment, all welding points cannot be inspected at once. In addition, in the case of visual inspection, if the closed structure or welding point is covered by another component, inspection may not be possible, as expected in the case of the camera. Welding is a process of combining different parts, and during the visual inspection in the process of manufacturing the body, there may be a situation where the welding point is covered or cannot be confirmed.

[0006] When inspecting welding quality by visual inspection, it is necessary to teach the visual robot a standard (i.e., set the reference position of the robot's welding point inspection). If the reference point teaching is unstable, the reliability of the quality inspection of the welding position will be reduced. In addition, it is practically impossible to measure a large number of welding points within the process production time (cycle time). Therefore, there is a problem in that a large amount of visual inspection equipment is required in order to inspect all welding points of more than 7,500 points within the processing time.

[0007] The above information disclosed in this Background section is only for enhancing understanding of the background of the present disclosure. Therefore, the Background section may contain information that does not constitute prior art that is already known to a person of ordinary skill in the art. Summary of the invention

[0008] The present disclosure provides a welding quality inspection device and method, which can compare, verify and compensate the positions of welding points in drawings and actual welding points. This is achieved by uploading the big data of the actual coordinates of the robot welding gun to the virtual space program.

[0009] The welding quality inspection device may include a welding position calculation part, which is configured to calculate a first virtual welding position based on an actual welding position of a robot welding gun. The device may also include a comparison and verification part, which is configured to calculate a first error by comparing the first virtual welding position with a reference welding position of a drawing, and determine that an inspection is required when the magnitude of the first error is within a reference range. The device may also include a calibration part, which is configured to generate a second virtual welding position based on the first virtual welding position by repeating the calibration until the ratio determined to be inspected becomes less than the preset standard when the ratio determined to be inspected by the comparison and verification part is a preset standard or greater. The device may also include a compensation part, which is configured to extract a second error between the second virtual welding position and the reference welding position when the calibration is completed, and compensate the second error when the second error is a predetermined reference value or greater.

[0010] The reference welding position, the first virtual welding position, and the second virtual welding position may be calculated as three-dimensional coordinates.

[0011] The calibration part may be configured to perform calibration in which a transformation matrix for compensating the first error is generated. The first virtual welding position is compensated by using the transformation matrix.

[0012] The transformation matrix may be calculated by comparing the first virtual welding position and the reference welding position. The first virtual welding position and the reference welding position are represented as vectors.

[0013] The comparison and verification part may be configured to determine the first virtual welding position as normal when the magnitude of the first error is less than a reference range. The comparison and verification part may also be configured to determine the first virtual welding position as defective when the magnitude of the first error is greater than a reference range.

[0014] The compensating part may compensate the first virtual welding position determined to be defective to match the reference welding position.

[0015] The reference range may be 5 mm to 10 mm.

[0016] The preset standard may be 80%.

[0017] The predetermined reference value may be 5 mm.

[0018] The compensation part can be configured to extract the three-dimensional coordinates of each of the second virtual welding position and the reference welding position to calculate the second error. The compensation part can also be configured to modify the robot program of the robot welding gun with the second error to compensate for the actual welding position of the robot welding gun.

[0019] The compensation part may be configured to send a first alarm message about a defect of the welding position when it is determined that compensation is required. The compensation part may also be configured to send a second alarm message informing that the welding position has been changed when compensation is completed.

[0020] The welding quality inspection method may include: calculating a first virtual welding position by uploading the coordinates of the robot welding gun relative to the actual welding position to the welding quality inspection device through the welding quality inspection device. The method may also include performing comparison and verification through the welding quality inspection device, wherein a first error may be calculated by comparing the first virtual welding position with a reference welding position of the drawing, and when the magnitude of the first error is within a reference range, it is determined that an inspection is required. The method may also include performing calibration, wherein, when it is determined that the ratio that needs to be inspected is a preset standard or greater, a second virtual welding position is generated based on the first virtual welding position generated by repeating the calibration until the ratio that needs to be inspected becomes less than the preset standard two.

[0021] Performing the calibration may include generating a transformation matrix for compensating for the first error, and compensating the first virtual welding position by using the transformation matrix.

[0022] The transformation matrix may be calculated by comparing the three-dimensional coordinate values ​​of the first virtual welding position and the reference welding position.

[0023] The welding quality inspection method may further include extracting a second error between the second virtual welding position and the reference welding position when the calibration is completed. In addition, the method may include compensating for the second error when the second error is a predetermined reference value or more.

[0024] Performing comparison and verification may include determining the first virtual welding position as normal when the magnitude of the first error is less than a reference range. Performing comparison and verification may also include determining the first virtual welding position as defective when the magnitude of the first error is greater than a reference range.

[0025] Compensating for the second error may include compensating the first virtual welding position determined to be defective to match the reference welding position.

[0026] Compensating for the second error may further include extracting coordinates of each of the second virtual welding position and the reference welding position to calculate the second error. Compensating for the second error may further include modifying a robot program of the robot welding gun using the second error to compensate for an actual welding position of the robot welding gun.

[0027] The reference range may be 5 mm to 10 mm.

[0028] The preset standard may be 80%.

[0029] The welding quality inspection device and method according to the embodiment can compare, verify and compensate the position of the welding point of the drawing and the position of the actual welding point. This can be achieved by uploading the big data of the actual coordinates of the robot welding gun to the virtual space program.

[0030] The welding quality inspection device and method according to the embodiment may prevent welding omission / separation by confirming the correct welding position. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] These drawings are only used as references in describing the embodiments of the present disclosure. Therefore, the technical idea of ​​the present disclosure should not be limited to the drawings.

[0032] Figure 1 is a diagram showing a welding quality inspection system according to an embodiment.

[0033] Figure 2 is a block diagram of a welding quality inspection device according to an embodiment.

[0034] Figure 3 is a flow chart of a welding quality inspection method according to an embodiment.

[0035] Figure 4 is a diagram showing a calibration procedure according to an embodiment.

[0036] Figure 5 is a diagram illustrating comparison and verification steps according to an embodiment.

[0037] Figure 6 is a diagram showing a calibration procedure according to an embodiment.

[0038] Figure 7 A transformation matrix according to an embodiment is shown.

[0039] Figure 8 is a flow chart of a welding quality inspection method according to an embodiment.

[0040] Fig. 9 is a diagram illustrating a computing device according to an embodiment. DETAILED DESCRIPTION

[0041] The embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings so that those of ordinary skill in the art can easily implement the embodiments. As will be appreciated by those of ordinary skill in the art, the described embodiments can be modified in various ways, all of which do not depart from the spirit or scope of the present disclosure. In order to clarify the present disclosure, parts that are not related to the description will be omitted, and throughout the specification, the same elements or equivalents are referred to with the same reference numerals.

[0042] In addition, unless explicitly stated to the contrary, the word "comprise" and its variations, such as "comprises" or "comprising", should be understood to imply the inclusion of the stated elements but not the exclusion of any other elements. Including terms such as first and second, are used to describe various constituent elements, but these constituent elements are not limited by these terms. These terms are only used to distinguish one component from other components.

[0043] In addition, the terms "unit", "component" or "portion", "-er", "module" in the specification refer to a unit that processes at least one function or operation, which can be implemented by hardware, software, or a combination of hardware and software.

[0044] When a component, device, element, etc. of the present disclosure is described as having a purpose or performing an operation, function, etc., the component, device or element should be considered herein as being “configured to” satisfy the purpose or perform the operation or function.

[0045] Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings.

[0046] Figure 1 1 is a diagram showing a welding quality inspection system according to an embodiment. The welding quality inspection system 1000 is configured to prevent defects and omissions of welding positions by using big data of welding position coordinates of a robot welding gun.

[0047] Reference Figure 1 The welding quality inspection system 1000 includes a welding quality inspection device 100 , a robot welding gun 200 , a robot controller 300 and a network server 400 .

[0048] The welding quality inspection device 100 may be a computing device connected to the robot welding gun 200 through a network. The welding quality inspection device 100 may check the data difference between the actual welding position and the drawing by using the big data of the actual welding position coordinates of the robot welding gun 200. In an embodiment, the welding quality inspection device 100 may implement the coordinates of the actual welding position of the robot welding gun 200 and the coordinates of the virtual welding position in the same manner. The welding quality inspection device 100 may autonomously compensate for the defects of the welding position so that the actual welding position matches the three-dimensional data of the drawing. The welding quality inspection device 100 may monitor and manage the history of the position / omission / defect of the welding point in real time. For example, the welding quality inspection device 100 compares the three-dimensional data of the drawing and the actual welding position data of the welding gun in real time, and sends an alarm message about the defect. Therefore, the welding quality inspection device prevents defective vehicles from being transferred to subsequent processes.

[0049] The robot welding gun 200 may be included in a welding robot. The robot welding gun 200 includes a tool center point (TCP) and is a part of the configuration of the welding robot that provides welding position coordinates. The welding robot includes a plurality of axes. Each axis of the welding robot is moved by a servo motor SM. An encoder EN is attached to the servo motor SM. The position data of the servo motor SM may be checked by the encoder EN, and the corresponding information may be checked / controlled by the robot controller 300. The TCP of the robot welding gun 200 determines the actual welding position using the center coordinates of the robot welding gun 200. The TCP may be converted into an XYZ coordinate system format by kinematics based on information about the 6 axes of the welding robot.

[0050] The robot welding gun 200 may upload data such as welding position coordinates to the welding quality inspection device 100 through the network server 400. In addition, the robot welding gun 200 may download a welding position autonomous compensation program from the welding quality inspection device 100.

[0051] The robot controller 300 may provide and control information about the welding robot including the robot welding gun 200 and the axis. The network server 400 may provide a network connecting the robot welding gun 200 and the welding quality inspection device 100 .

[0052] Figure 2 is a block diagram of a welding quality inspection apparatus 100 according to an embodiment.

[0053] Reference Figure 2 The welding quality inspection device 100 may include a welding position calculation part 110 , a comparison and verification part 120 , a calibration part 130 , and a compensation part 140 .

[0054] The welding quality inspection device 100 can receive big data of the actual coordinates of the robot welding gun 200 via TCP, and can compare and verify the reference welding position of the drawing and the actual welding position of the robot welding gun. The welding quality inspection device 100 can be connected to a robot program 500 that controls the movement of a welding robot including the robot welding gun 200. The robot program 500 includes information about each axis of the welding robot. The TCP representing the actual welding position of the robot welding gun 200 can be determined by the information about each axis of the welding robot. In other words, the robot program 500 can determine the actual welding position of the robot welding gun 200. In the present disclosure, the welding point position may refer to the actual welding position.

[0055] The welding position calculation part 110 may receive information about the actual welding position from the robot program 500. The welding position calculation part 110 may calculate a first virtual welding position based on the received actual welding position. The first virtual welding position is data calculated in a computing device of the welding quality inspection apparatus 100 based on the actual welding position. For example, the welding position calculation part 110 may convert each axis value included in the robot program 500 and calculate the first virtual welding position.

[0056] The first virtual welding position reflects the actual welding position and may not look exactly the same as the actual welding position due to a slight error caused by the mechanical operation (e.g., driving) of the welding robot. In other words, when the actual welding position of the robot welding gun is uploaded to the virtual space program of the welding quality inspection device 100, no completely matching data is uploaded, and errors may occur. For example, errors may occur due to aging and / or mechanical defects of the welding robot, etc. In addition, the actual welding position may not match the reference welding position of the drawing including the theoretical value, and may have a certain degree of error.

[0057] The welding quality inspection device 100 can modify the uploaded virtual welding position to match the actual welding position. The welding quality inspection device 100 can also perform compensation for matching the matched virtual welding position with the reference welding position of the drawing, through which the welding quality can be checked and improved.

[0058] The comparison and verification part 120 detects the error by comparing the actual welding position with the reference welding position through the big data of the actual coordinates of the robot welding gun, and the reference welding position is a theoretical value extracted from the drawing. The comparison and verification part 120 can calculate the first error by comparing the first virtual welding with the reference welding position shown in the drawing. By uploading the actual welding position, the first virtual welding position is obtained through the big data of the coordinates. When the size of the first error is within a predetermined reference range, the comparison and verification part 120 can determine that an inspection is required. In addition, when the size of the first error is less than the reference range, the comparison and verification part 120 can determine that the first virtual welding position is normal. When the size of the first error is greater than the reference range, the comparison and verification part 120 can also determine that the first virtual welding position is defective. The comparison and verification part 120 can exclude the first virtual welding position determined to be defective from the calibration, and then immediately provide it to the compensation part 140 for compensation.

[0059] In an embodiment, the welding quality inspection device 100 can perform virtual calibration to compensate for errors. The data that ensures reliability through calibration can correctly upload the actual welding position to the first virtual welding position, and based on this, the welding quality inspection device 100 can compare the reference welding position of the drawing with the actual welding position. The embodiment of the present disclosure performs virtual calibration, in which mathematical formulas are solved by minimizing time and cost.

[0060] The calibration part 130 may perform a virtual calibration to match the first virtual welding position with the actual welding position. In an embodiment, when the comparison and verification part 120 determines that the ratio that needs to be checked is greater than or equal to the preset standard according to the size of the first error, the calibration part 130 may perform calibration. The calibration part 130 may repeatedly perform calibration until it is determined that the ratio that needs to be checked becomes less than the preset standard. The calibration part 130 may generate a second virtual welding position based on the first virtual welding position. Specifically, when it is determined that the ratio that needs to be checked becomes less than the preset standard according to repeated calibration of the first virtual welding position, the calibration part 130 may complete the calibration and define the virtual welding position finally generated as the second virtual welding position. In other words, the second virtual welding position may be data uploaded for matching the actual welding position by ensuring reliability according to the calibration.

[0061] When the calibration is completed, the compensation part 140 can extract a second error between the second virtual welding position and the reference welding position of the drawing, and when the extracted second error is a predetermined reference value or more, compensate the second error. The reference welding position, the first virtual welding position, and the second virtual welding position can be calculated as three-dimensional coordinates.

[0062] In an embodiment, the compensation part 140 can compare the actual welding position with the reference welding position through the second virtual welding position, and the reference welding position is the coordinates of the welding point indicated in the drawing. The compensation part 140 can also determine whether to modify and send an alarm message.

[0063] For example, when a welding point or welding position is to be modified, the compensation part 140 can inform the modification reason of the corresponding welding point, and calculate the coordinate system modification value based on the comparison with the drawing. The compensation part 140 can modify the robot program by using the error value calculated in the x, y, and z coordinates, and autonomously compensate the position of the robot welding gun through a network server connected to the robot controller. Therefore, the compensation part 140 can match the welding point position with the drawing. In an embodiment, the compensation part 140 can compensate for the first virtual welding position determined to be defective by the comparison and verification part 120 to match the reference welding position. In other words, the first virtual welding position determined to be defective can be compensated by the compensation part 140 immediately without calibration.

[0064] Figure 3 is a flow chart of a welding quality inspection method according to an embodiment.

[0065] exist Figure 3 In step S100, the welding quality inspection device 100 may upload the coordinates of the actual welding position of the robot welding gun to the virtual space program of the welding quality inspection device 100. In addition, in step S100, the welding quality inspection device 100 may calculate the first virtual welding position. The virtual space program may correspond to the simulation in the computing server of the welding quality inspection device 100.

[0066] In step S200 , the welding quality inspection apparatus 100 may perform virtual calibration with respect to a first virtual welding position uploaded in a virtual space program, and match an actual welding position with the first virtual welding position.

[0067] In more detail, in step S210 , the welding quality inspection device 100 may compare and verify the welding point positions of the drawing and the welding point positions of the actual robot gun.

[0068] In step S220, the welding quality inspection device 100 may determine a conformity "d" between the first virtual welding position and the actual welding position. In an embodiment, the welding quality inspection device 100 may calculate an error by comparing the first virtual welding position and the reference welding position of the drawing. The welding quality inspection device 100 may also perform calibration when the ratio of welding points with a calculated error within the range of 5 mm to 10 mm is 80% or more of all cases. In other words, calibration may be performed when the conformity "d" between the first virtual welding position and the reference welding position is 20% or less.

[0069] In step S230, the welding quality inspection device 100 may perform a simple robot calibration for matching the actual space and the virtual space. The matching of the actual space and the virtual space may be a match between the actual welding point position and the virtual welding point position uploaded to the simulation. The simple robot calibration is a virtual calibration and may be referred to as an advanced calibration.

[0070] The welding quality inspection device 100 may perform comparison and verification on the first virtual welding position modified by calibration relative to the reference welding position. The welding quality inspection device 100 may also recheck whether the welding position with an error within the range of 5 mm to 10 mm is 80% or more of the entire welding position. When the situation where the error of the modified first virtual welding position within the range of 5 mm to 10 mm still exceeds 80%, the welding quality inspection device 100 may perform calibration again. When the ratio of welding points with an error within the range of 5 mm to 10 mm of the first virtual welding position finally modified after repeated calibration is less than 80%, the welding quality inspection device 100 may stop further calibration.

[0071] For example, according to the equipment on the welding robot and the quality level of the robot and the components, when a welding robot should weld 20 points, i.e., 20 welding positions, the welding quality inspection device 100 can determine that the difference within 5 mm between the reference welding position of the drawing and the actual welding position is normal (e.g., acceptable). For the position difference between 5mm and 10mm, the welding quality inspection device 100 can check whether the actual welding position matches the virtual welding position, and the modification of the welding position can be performed by calibration. For example, when 80% or more of the 20 welding positions are outside the reference welding position and within the range of 5mm to 10mm, it can be determined that the calibration of the welding robot is defective. In this case, the welding quality inspection device 100 can perform virtual calibration (advanced calibration). In this case, the welding quality inspection device 100 performs a modification to match the first virtual welding position with the reference welding position through virtual calibration.

[0072] For welding positions having a difference of 10 mm or more, the welding quality inspection device 100 excludes them from the virtual calibration. However, the welding quality inspection device 100 may perform compensation of welding positions of these welding points in the future.

[0073] In step S240 , the welding quality inspection apparatus 100 may generate a transformation matrix for data error compensation, and modify the welding point position by using the transformation matrix.

[0074] In an embodiment, unlike conventional calibration, the virtual calibration of the present disclosure does not require measurement equipment. The actual space coordinates and the virtual space coordinates can be matched by using the three-dimensional position information data on the drawing and the big data information of the actual welding position of the welding gun.

[0075] The welding quality inspection device 100 may compare all welding point position data of the robot welding gun with the drawing welding point position data and calculate the difference in values.

[0076] The value obtained by reversely calculating the difference between the first virtual welding position implemented in the virtual space of the welding quality inspection device 100 based on the actual welding position and the reference welding position of the drawing is called a conversion matrix. The welding quality inspection device 100 can select the conversion matrix of the position data of each welding point owned by the welding robot as a model through optimization modeling, and can determine it as the final conversion matrix of a welding robot. Since this is a method of setting a standard value, when the actual welding position of the robot welding gun and the three-dimensional virtual welding position of the drawing deviate by 10mm or more, the welding quality inspection device 100 can select it as defective and exclude it from the conversion matrix. The welding quality inspection device 100 can compensate the position and coordinate value of each welding point by calibration in the virtual space program using the final conversion matrix, and then the comparison and verification of the welding points can be performed again. When 80% or more of the welding positions still deviate from the reference welding position by 5mm to 10mm after repeated comparison and verification, the welding quality inspection device 100 can repeatedly perform virtual calibration work by using the compensated result value. As a result, the process increases the accuracy of calibration to match the actual welding position of the welding gun in the real space and the virtual position data of the welding gun in the virtual space.

[0077] In step S300, the welding quality inspection device 100 may compare the second virtual welding position generated by calibration with the reference welding position and determine whether to compensate the welding position. Figure 8 Provide a detailed explanation.

[0078] Figure 4 is a diagram showing a calibration procedure according to an embodiment.

[0079] exist Figure 4 4, the actual welding position TCP corresponds to the actual welding point, that is, the location where the real robot welding gun actually performs welding. The actual welding point can be confirmed by the photo 410 showing the actual welding point position. In the photo 410 showing the actual welding point position, as an example, the actual welding position TCP of four welding points is shown.

[0080] In the figure 420 before advanced virtual calibration, it can be seen that the first virtual welding position is uploaded based on the actual welding position TCP and is mapped on the figure. In the figure 420 before advanced virtual calibration, it can be seen that the reference welding position REF and the first virtual welding position TCP1 are spaced apart from each other by a first error. In the figure 420 before advanced virtual calibration, the reference welding position REF and the first virtual welding position TCP1 corresponding to the four welding points existing in the photograph 410 showing the actual welding point positions can be confirmed.

[0081] Referring to the photo 410 showing actual welding point positions and the diagram 420 before advanced virtual calibration, it can be seen that although the first virtual welding position TCP1 is uploaded based on the actual welding position TCP, there is an error between the actual welding position TCP and the first virtual welding position TCP1.

[0082] The graph 430 after the advanced virtual calibration shows the first virtual welding position TCP1 and the second virtual welding position TCP2. The second virtual welding position TCP2 corresponds to data obtained after repeatedly performing the virtual calibration (or the advanced virtual calibration) based on the first virtual welding position TCP1.

[0083] In the diagram 430 after the advanced virtual calibration, the second virtual welding position TCP2 is set at a position modified from the first virtual welding position TCP1 according to the calibration. The second virtual welding position TCP2 is compared with the first virtual welding position TCP1 to more accurately reflect the actual welding position TCP.

[0084] The drawing-actual weld point position comparison graph 440 shows the reference weld position REF of the drawing and the second virtual weld position TCP2 generated according to the calibration.

[0085] In the drawing-actual welding point position comparison diagram 440, the reference welding position REF of the drawing and the second virtual welding position TCP2 are set apart from each other by a second error. It can be seen that the second virtual welding position TCP2 is set closer to the reference welding position REF than the first virtual welding position TCP1 of the diagram 420 before the advanced virtual calibration. In other words, the second error may be smaller than the first error on average.

[0086] When comparing the graph 440 of the drawing-actual welding point position comparison and the photograph 410 showing the actual welding point position, it can be seen that the second virtual welding position TCP2 generated according to the calibration matches the actual welding position TCP.

[0087] Figure 5 is a diagram illustrating comparison and verification steps according to an embodiment. Figure 6 is a diagram showing a calibration procedure according to an embodiment. Figure 7 A conversion matrix according to an embodiment is shown.

[0088] Figure 5 Shown in detail in Figure 4 A comparison and verification step before the calibration step. Figure 5 In the present invention, the actual welding position TCP can be calculated based on multiple axes (e.g., the 1st axis to the 6th axis) of the welding robot. The actual welding position TCP can be generated by a robot program including axis information. Generally, one welding robot performs welding of multiple welding points. For example, the actual welding position TCP can be generated for the 5th welding point, the 6th welding point, and the 7th welding point, respectively.

[0089] The first virtual welding position TCP1 may be generated as a result of uploading information about the actual welding position TCP generated by the robot program to the simulation. The first virtual welding position may be shown on the diagram and include coordinates. For example, the first virtual welding position TCP1 of the 5th welding point, the 6th welding point, and the 7th welding point may correspond to the actual welding position TCP of the 5th welding point, the 6th welding point, and the 7th welding point, respectively. The first virtual welding position TCP1 may not match the reference welding position REF (which is a theoretical value shown on the diagram), but may be separated from the reference welding position REF by a first error.

[0090] The comparison and verification part 120 can compare and verify the actual welding position TCP (which is the actual welding point position value) and the reference welding position REF of the drawing. In order to determine whether to compensate the welding position, the comparison and verification part 120 calculates the error between the actual welding position TCP and the reference welding position REF of the drawing. Since the actual welding position TCP is an actual value, the comparison and verification part 120 can compare and verify the first virtual welding position TCP1 mapped on the drawing based on this with the reference welding position REF.

[0091] The comparison and verification part 120 can calculate the coordinate value by converting the coordinates of the information about the actual welding position including the axis information and the information about the reference welding position of the drawing. The comparison and verification part 120 can calculate the error by comparing the calculated coordinate values. In an embodiment, when the first error between the calculated first virtual welding position TCP1 and the reference welding position REF is 5 mm or less, the comparison and verification part 120 can determine that it is normal (OK), when it is between 5 mm and 10 mm, it is determined that it needs to be checked (CHECK), and when it is 10 mm or more, it is determined that it is defective (NG).

[0092] For example, in Figure 5, it can be seen that the error between the reference welding position REF and the first virtual welding position TCP1 of the 5th welding point is 13.2, and is determined to be defective. It can also be seen that the error between the reference welding position REF and the first virtual welding position TCP1 of the 6th welding point is 4.2, and is determined to be normal. In addition, it can be seen that the error between the reference welding position REF and the first virtual welding position TCP1 of the 7th welding point is 4.1, and is determined to be normal.

[0093] Figure 6 Shown in detail Figure 5 The calibration step follows the comparative verification step in Figure 4 The following description will be made of a photograph 410 showing actual welding point positions, a picture 420 before advanced virtual calibration, and a picture 430 after advanced virtual calibration.

[0094] exist Figure 6 In FIG. 420 before the advanced virtual calibration, the first virtual welding position TCP1 is spaced apart from the reference welding position REF by a first error. In the table showing the error between the reference welding position REF and each of the first virtual welding positions TCP1 from the 1st welding point to the 9th welding point, it can be seen that when the error is 5 mm to 10 mm, it is determined to be required to be checked (CHECK), and when the error exceeds 10 mm, it is determined to be defective (NG). For example, in the case of the 5th welding point, the error corresponds to 20.5 mm and is determined to be defective (NG), so that it may be necessary to exclude it from the calibration and immediately compensate it by the compensation part 140 (refer to Figure 2 ). Since the error of each of the 1st to 4th welding points and the 6th to 9th welding points except the 5th welding point seems to be within the reference range of 5 mm to 10 mm, it is determined that a check is required.

[0095] Therefore, if it is determined that the ratio of welding points that need to be checked exceeds 80% of all welding points, the welding quality inspection device 100 may determine that advanced calibration is required.

[0096] Referring to the diagram 430 after the advanced virtual calibration, the welding quality inspection apparatus 100 can perform the calibration by using the coordinates (R real )'s transformation matrix T a To perform virtual calibration, the coordinates (R tran ).

[0097] When comparing the second virtual welding position TCP2 of the diagram 430 after advanced virtual calibration with the actual welding position TCP of the photograph 410 showing the actual welding point position, it can be seen that they match (ie, coincide with) each other.

[0098] Figure 7 Shows that the generated Figure 6 The transformation matrix used in the calibration.

[0099] exist Figure 7 The three-dimensional coordinate matrix R of the actual welding point real The coordinate matrix R of the welding point corresponds to the actual welding position value of the robot welding gun. ideal The coordinates of the reference welding position in the three-dimensional virtual space corresponding to the drawing. The coordinate matrix R of the welding point in the drawing ideal The value obtained by moving the position of the robot's welding gun to the reference welding position of the drawing in the virtual space and calculating the position data of the welding gun in the predetermined coordinate system. a is a value obtained by comparing the actual welding position of the actual welding point with the reference welding position of the welding point on the drawing, and can be expressed as a vector. In an embodiment, the welding quality inspection device 100 can compare n (for example, twenty) welding points / each welding robot and extract the transformation matrix T 1 To T n Each of them, and then calculate the transformation vector T through optimization modeling OM a (T average ).

[0100] Figure 8 is a flow chart of a welding quality inspection method according to an embodiment.

[0101] exist Figure 8 In step S100, the welding quality inspection device 100 may upload data of the actual coordinates of the robot welding gun to the virtual simulation program. Thereafter, the welding quality inspection device 100 may match the actual welding position and the virtual welding position through virtual calibration. For the virtual calibration step S200, reference may be made to Figure 3 Description of the process.

[0102] In step S250, the welding quality inspection device 100 can perform a comparison and verification of the position of the drawing and the actual welding point based on the information of the matched welding position. In other words, the welding quality inspection device 100 can compare and verify the second virtual welding position of the matching actual welding point mapped on the drawing with the theoretical value of the reference welding position of the drawing.

[0103] The welding quality inspection device 100 compares the reference welding position of the drawing with the actual welding position, and when the actual welding position needs to be modified, the welding quality inspection device 100 can perform step S400. In step S400, the welding quality inspection device 100 can perform position compensation of the welding point, wherein the welding quality inspection device 100 can inform the modification reason of the corresponding welding position, compare it with the reference welding position of the drawing, and calculate the modification value of the coordinate system of the welding point.

[0104] For example, when the error "c" between the actual welding position and the reference welding position of the drawing is a reference value of 5 mm or more, the welding quality inspection device 100 can determine that the position modification of the welding point is required. In addition, when the reference value is less than 5 mm, the welding quality inspection device 100 can determine that the position modification of the welding point is not required.

[0105] In step S410 , when it is determined that the position modification of the welding point is required, the welding quality inspection device 100 may send a first alarm message having information about the change of the welding point position and the potential omission of the welding point position.

[0106] In step S420 , the welding quality inspection device 100 may compare the reference welding position of the drawing with the actual welding position of the actual welding point and calculate the error in the three-dimensional coordinates.

[0107] In step S430, the welding quality inspection device 100 may modify the data in the robot program 500 using the calculated error (refer to Figure 2 ) so that the welding robot can download the data.

[0108] In step S440 , when the position modification of the welding point is completed, the welding quality inspection device 100 may transmit a second alarm message regarding the position change of the welding point (step S440 ).

[0109] Fig. 9 is a diagram for explaining a computing device according to an embodiment.

[0110] Reference Fig. 9 , the welding quality inspection apparatus and method according to the embodiment may be implemented by using the computing device 50 .

[0111] The computing device 50 may include at least one of a processor 510, a memory 530, a user interface input device 540, a user interface output device 550, and a storage device 560 that communicate via a bus 520. The computing device 50 may also include a network interface 570 that is electrically connected to the network 40. The network interface 570 may transmit or receive signals with other entities via the network 40.

[0112] The processor 510 may be implemented in various types, such as a microcontroller unit (MCU), an application processor (AP), a central processing unit (CPU), a graphics processing unit (GPU), a neural processing unit (NPU), etc. In addition, the processor 510 may be any type of semiconductor device capable of executing instructions stored in the memory 530 or the storage device 560. The processor 510 may be configured to implement the above reference Figure 1-8 Describes the functions and methods.

[0113] The memory 530 and the storage device 560 may include various types of volatile or non-volatile storage media. For example, the memory may include a read-only memory (ROM) 531 and a random access memory (RAM) 532. In this embodiment, the memory 530 may be located inside or outside the processor 510, and the memory 530 may be connected to the processor 510 by various known means.

[0114] In some embodiments, at least some configurations or functions of the welding quality inspection apparatus and method according to the embodiments may be implemented as a program or software executable by the computing device 50. In addition, the program or software may be stored in a computer-readable medium.

[0115] In some embodiments, at least some of the configurations or functions of the welding quality inspection apparatus and method according to the embodiments may be implemented by using the hardware or circuit device of the computing device 50. In other embodiments, at least some of the configurations or functions of the welding quality inspection apparatus and method according to the embodiments may also be implemented as separate hardware or circuit devices that may be electrically connected to the computing device 50.

[0116] Although the embodiments of the present disclosure have been described in detail above, the scope of the present disclosure is not limited thereto, and various modifications and improvements made by ordinary technicians in the field also fall within the scope of the present disclosure.

Claims

1. A welding quality inspection device, comprising: a welding position calculation section configured to calculate a first virtual welding position based on an actual welding position of the robot welding gun; The comparison and verification part is configured as follows: calculating a first error by comparing the first virtual welding position with a reference welding position of the drawing, and When the magnitude of the first error is within a reference range, determining that an inspection is required; a calibration section configured to: when the ratio that needs to be checked is determined by the comparison and verification section to be a preset standard or more, generate a second virtual welding position based on the first virtual welding position by repeating the calibration until the ratio that needs to be checked becomes smaller than the preset standard; as well as A compensation part is configured to extract a second error between the second virtual welding position and the reference welding position when the calibration is completed, and compensate for the second error when the second error is a predetermined reference value or more. 2 . The welding quality inspection device according to claim 1 , wherein the reference welding position, the first virtual welding position, and the second virtual welding position are calculated as three-dimensional coordinates. 3 . The welding quality inspection device according to claim 2 , wherein the calibration part is configured to perform calibration in which a transformation matrix for compensating the first error is generated, and wherein the first virtual welding position is compensated by using the transformation matrix. 4 . The welding quality inspection device according to claim 3 , wherein the conversion matrix is ​​calculated by comparing the first virtual welding position and the reference welding position, and wherein the first virtual welding position and the reference welding position are represented as vectors.

5. The welding quality inspection device according to claim 1, wherein the comparison and verification section is configured as follows: When the magnitude of the first error is smaller than the reference range, determining that the first virtual welding position is normal, and When the magnitude of the first error is greater than the reference range, the first virtual welding position is determined to be defective. 6 . The welding quality inspection device according to claim 5 , wherein the compensation portion compensates the first virtual welding position determined to be defective to match the reference welding position. 7 . The welding quality inspection device according to claim 1 , wherein the reference range is 5 mm to 10 mm.

8. The welding quality inspection device according to claim 1, wherein the preset standard is 80%. 9 . The welding quality inspection device according to claim 1 , wherein the predetermined reference value is 5 mm.

10. The welding quality inspection device according to claim 2, wherein the compensation part is configured as: extracting three-dimensional coordinates of each of the second virtual welding position and the reference welding position to calculate the second error, and A robot program of the robotic welding gun is modified using the second error to compensate for the actual welding position of the robotic welding gun.

11. The welding quality inspection device according to claim 10, wherein the compensation part is configured as: When it is determined that the compensation is required, sending a first warning message about a defect in the welding location, and When the compensation is completed, a second alarm message is sent to inform that the welding position has been changed.

12. A welding quality inspection method, comprising: By means of a welding quality inspection device, a first virtual welding position is calculated by uploading coordinates of a robot welding gun relative to an actual welding position to the welding quality inspection device; By means of the welding quality inspection device, comparison and verification are performed, wherein a first error is calculated by comparing the first virtual welding position with a reference welding position of a drawing, and when the magnitude of the first error is within a reference range, it is determined that an inspection is required; Perform calibration; as well as When it is determined that the ratio requiring inspection is a preset standard or more, a second virtual welding position is generated based on the first virtual welding position generated by repeating calibration until the ratio requiring inspection becomes smaller than the preset standard.

13. The welding quality inspection method according to claim 12, wherein performing calibration comprises: generating a transformation matrix for compensating for the first error; and The first virtual welding position is compensated by using the transformation matrix. 14 . The welding quality inspection method according to claim 13 , wherein the transformation matrix is ​​calculated by comparing three-dimensional coordinate values ​​of the first virtual welding position and the reference welding position.

15. The welding quality inspection method according to claim 12, further comprising: When the calibration is completed, extracting a second error between the second virtual welding position and the reference welding position; and When the second error is a predetermined reference value or more, the second error is compensated.

16. The welding quality inspection method according to claim 15, wherein performing comparison and verification comprises: When the magnitude of the first error is smaller than the reference range, determining that the first virtual welding position is normal; and When the magnitude of the first error is greater than the reference range, the first virtual welding position is determined to be defective.

17. The welding quality inspection method according to claim 16, wherein compensating the second error comprises: The first virtual welding position determined to be defective is compensated to match the reference welding position.

18. The welding quality inspection method according to claim 15, wherein compensating the second error further comprises: extracting coordinates of each of the second virtual welding position and the reference welding position to calculate the second error; and A robot program of the robotic welding gun is modified using the second error to compensate for the actual welding position of the robotic welding gun.

19. The welding quality inspection method according to claim 12, wherein the reference range is 5 mm to 10 mm.

20. The welding quality inspection method according to claim 12, wherein the preset standard is 80%.

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