JP7702376B2 - Welding work evaluation system - Google Patents

Description

The present invention relates to a system for evaluating welding work skills.

Until now, highly advanced skills such as welding have been taught to beginners through on-the-job training by experienced welders over a long period of time. However, with the rapid decline in skilled welders due to the recent low birthrate and aging population, beginners do not always have access to training from experts, and skilled skills are rapidly being lost from manufacturing sites. In this situation, efforts are being made to automate welding work using robots, which has been successful in reducing labor hours and stabilizing quality. However, there is still a high need for manual welding in narrow spaces that robots cannot access, and for welding large structures with large dimensional variations, and there is a demand for a system to efficiently train the next generation of welders.

In light of these recent circumstances, several systems and methods for supporting education in welding work have been proposed. For example, Patent Document 1 discloses a system and method for providing arc welding training in a simulated virtual reality environment or an augmented reality environment, and for providing the virtual reality welding system with the import and analysis of external data. Patent Document 2 discloses a welding work evaluation device for more appropriately evaluating welding work skills.

Special table 2016-511446 publication JP 2021-189380 A

In conventional technology, to evaluate welding skills, the welding motion of a welding worker must be measured using measuring devices, and the measured welding motion must be evaluated or scored based on data of ideal welding motion (hereinafter referred to as "ideal motion data"). In actual welding, welding workers adopt a variety of postures. Welding postures can be broadly divided into a downward posture in which welding is performed while looking down at the material to be welded, an upward posture in which welding is performed while looking up, a horizontal posture in which welding is performed sideways to the direction of gravity, and a vertical posture in which welding is performed parallel to the direction of gravity. Therefore, to evaluate welding skills, ideal motion data must be prepared for each of these postures.

Furthermore, when welding pipes, which are often found in plants such as factories and power plants, if the pipes are fixed, the welding worker will change his/her posture while welding. For this reason, ideal motion data is required for all welding positions other than those mentioned above. The ideal motion data is stored in a database and used. The database that stores the ideal motion data is called the "ideal motion database."

Thus, in conventional technology, in order to evaluate welding skills, it is necessary to store a large amount of ideal motion data corresponding to various welding positions in an ideal motion database. The problem with the ideal motion database is that it takes a lot of time and money to build, because it needs to be constructed by examining the relationship between welding conditions (current, voltage, welding speed, welding torch angle, etc.) and welding defects through welding experiments. For this reason, there is a demand for a system that can easily evaluate welding work skills without having to build an ideal motion database corresponding to various welding positions.

The present invention aims to provide a welding work evaluation system that can easily evaluate welding work skills.

The welding operation evaluation system according to the present invention includes a measuring device that measures the movement of a welding torch held by a welding operator who welds the workpiece, a database that stores multiple reference data, an ideal movement data generation unit that generates ideal movement data for a weld angle using the multiple reference data, and a welding operation evaluation unit that scores the welding operation of the welding operator obtained from the movement of the welding torch measured by the measuring device based on a scoring algorithm and the ideal movement data. The reference data is data on the welding operation that is arbitrarily determined according to the welding posture. The weld angle is the angle of the workpiece relative to a predetermined reference plane. The ideal movement data is data on the welding operation that the welding operator aims to achieve. The scoring algorithm is a method for scoring the welding operation of the welding operator.

The present invention provides a welding work evaluation system that can easily evaluate welding work skills.

1 is a schematic diagram showing a configuration of a welding operation evaluation system according to a first embodiment of the present invention and a welding operation performed by a welding operator; 13A and 13B are diagrams showing examples of measurement data and scoring results displayed on an output interface. 4 is a flowchart of a process for scoring the welding operation of a welding operator, which is executed by the welding operation evaluation system according to the first embodiment. FIG. 4 is a diagram illustrating an example of a scoring algorithm in the first embodiment. 11 is a diagram for explaining an example of a method for calculating the contribution of each piece of reference data to an operation parameter; FIG. FIG. 11 is a diagram showing an example of scoring of motion parameters in the first embodiment. FIG. 11 is a schematic diagram showing a configuration of a welding operation evaluation system according to a second embodiment of the present invention and a welding operation performed by a welding operator. FIG. 13 is a diagram illustrating an example of a scoring algorithm in the second embodiment. FIG. 13 is a diagram illustrating an example of a scoring algorithm in the second embodiment. FIG. 13 is a diagram illustrating an example of a scoring algorithm in the second embodiment. FIG. 11 is a diagram for explaining an example of a method for calculating a weld angle φn in the second embodiment. FIG. 11 is a diagram showing an example of scoring of motion parameters in the second embodiment. FIG. 11 is a diagram showing an example of ideal motion data generated in the second embodiment. 11B is a diagram showing values of motion parameters (welding speed) in the welding work of a welding operator and scores as the scoring results thereof, in addition to the ideal motion data shown in FIG. 11A.

Welding is a complex task that combines many physical phenomena. Experienced welders use their extensive experience to fine-tune the welding conditions when performing welding. For example, even when using the same welding method, the way gravity acts on the molten metal differs between overhead welding, where welding is performed while looking up at the joint, and downward welding, where welding is performed while looking down at the joint. In general, when welding in the overhead position, the weld metal is prone to dripping during welding, so it is necessary to increase the welding speed to allow the weld metal to solidify quickly.

As described above, in conventional technology, in order to evaluate welding skills, the ideal motion database needs to store a large amount of ideal motion data corresponding to various welding positions. However, building such an ideal motion database is difficult and requires a lot of time and money. For example, in the technology disclosed in the above-mentioned Patent Document 1, the welding positions that can be evaluated are limited. Also, for example, Patent Document 2 describes a case where the welding position changes gradually, but does not take into account a case where the welding position of the welding worker differs from the reference data. Thus, with conventional technology, it is difficult to evaluate welding skills in an actual field where work is performed in various welding positions.

In the welding work evaluation system according to the present invention, even if the welding posture of a welding worker differs from the reference data (reference data), ideal motion data is generated from the reference data and a scoring algorithm is used to evaluate the welding skill. Therefore, the welding work evaluation system according to the present invention can easily evaluate welding work skills (welding skills) without having to build an ideal motion database corresponding to various welding postures.

The welding work evaluation system according to the embodiment of the present invention will be described below with reference to the drawings. The welding work evaluation system according to the embodiment evaluates the welding skills of a welding worker by scoring the welding action of the welding worker. In the following embodiment, as an example, an example in which a welding worker performs arc welding will be described. Note that in the drawings used in this specification, identical or corresponding components are given the same reference numerals, and repeated explanations of these components may be omitted.

Figure 1 is a schematic diagram showing the configuration of a welding work evaluation system according to a first embodiment of the present invention and the welding work of a welding worker 50.

The welding torch 2 is connected to the digital welding machine 1 and is held by a welding operator 50. When power is supplied from the digital welding machine 1 to the welding torch 2, the welding operator 50 holds the welding torch 2 and performs welding work on the workpiece 3. A weld bead 4 is formed on the workpiece 3 by the welding work.

The welding work evaluation system according to this embodiment includes a sensor 6, a measuring device 7, a data logger 8, and a control device 10, and evaluates the welding work skills (welding skills) of a welding worker 50. The devices shown in FIG. 1, for example, the digital welding machine 1, the measuring device 7, the data logger 8, and the control device 10, are connected to each other via a communication network such as a wireless LAN or a wired LAN.

Digital welding machine 1 is connected to welding torch 2 and supplies the power and welding material (filler metal) required for welding. Digital welding machine 1 has the function of managing the current, voltage, and amount of welding material supplied to welding torch 2.

The data logger 8 acquires information on the current, voltage, and amount of welding material supplied to the welding torch 2 from the digital welding machine 1 and supplies the information to the control device 10. The data logger 8 also acquires information on the operation of the welding torch 2 measured by the measurement device 7 from the measurement device 7 and supplies the information to the control device 10.

The angle of the surface of the weld of the workpiece 3 relative to a predetermined reference plane (e.g., a horizontal plane) is called the weld angle 5. The weld angle 5 can be determined by the control device 10, as described below. In addition, if the weld angle 5 is known in advance, it can also be input to the control device 10 by the operator (user) of the welding work evaluation system.

The sensor 6 is attached to the welding torch 2 and measures the position, attitude, and movement of the welding torch 2. The sensor 6 can be composed of, for example, at least one of a GPS sensor, a horizontal sensor, and a gyroscope.

The measuring device 7 is a device that measures the operation of the welding torch 2. The measuring device 7 measures the operation of the welding torch 2 relative to the workpiece 3 (e.g., the angle relative to the workpiece 3, the welding speed, the torch height, etc.) by, for example, acquiring the position of the tip of the welding torch 2. The measuring device 7 can measure the operation of the welding torch 2 using information from the sensor 6, or can measure the operation of the welding torch 2 without using information from the sensor 6.

The measuring device 7 can be configured with any device. When the measuring device 7 measures the movement of the welding torch 2 using information from the sensor 6, the measuring device 7 can be configured with a device that calculates and determines the movement of the welding torch 2 from the measurement value of the sensor 6. Also, for example, if the measuring device 7 can be installed around the welding operator 50, the measuring device 7 can be equipped with a motion capture camera or a stereo camera, and the movement of the welding torch 2 can be determined from the video data of this camera. In a configuration in which the measuring device 7 is equipped with a camera, the measuring device 7 can measure the movement of the welding torch 2 without using information from the sensor 6.

Figure 1 shows, as an example, a configuration in which a camera-type measuring device 7 is used to determine the movement of the welding torch 2. The measuring device 7 shown in Figure 1 is composed of a camera, but it is also possible to measure the movement of the welding torch 2 using information from a sensor 6. Note that because a strong arc light is generated during actual welding, it is necessary to use a sensor 6 and camera that are not easily affected by this light.

Information on the operation of the welding torch 2 measured by the measuring device 7 is supplied to the control device 10 via the data logger 8.

The control device 10 inputs information on the current, voltage, and amount of welding material supplied to the welding torch 2 via the data logger 8, as well as information on the operation of the welding torch 2 measured by the measurement device 7.

The control device 10 includes an input interface 20, a calculation device 30, and an output interface 40. The shape and position (spatial coordinates of the position to be welded) of the workpiece 3 are input in advance by the user, and the control device 10 stores these.

The input interface 20 is operated by the user to input setting values required for the calculations performed by the control device 10 and scoring algorithms specified by the user to the control device 10. The input interface 20 can be configured, for example, with a keyboard and a touch panel.

The setting values required for the calculation are, for example, the scoring section and the scoring interval. The scoring section is the time range in which scoring is performed. The scoring interval is the time interval for scoring in the scoring section. Scoring refers to assigning a score to the welding action of the welding operator 50. The welding action of the welding operator 50 is measured and scored. Furthermore, if the weld angle 5 is known in advance, the weld angle 5 can be included in the setting values input by the input interface 20.

The scoring algorithm is a method for scoring the welding action of the welding worker 50. The welding action of the welding worker 50 is scored according to this scoring algorithm for each parameter (operation parameter) that represents the welding action. For example, one or more scoring algorithms are stored in advance in the control device 10, and the user can select and specify one from these depending on the welding method and the level of skill of the welding worker 50. The user selects and specifies the scoring algorithm by operating the input interface 20.

The arithmetic device 30 is composed of a computer and includes general computer hardware such as a CPU (Central Processing Unit), RAM (Random Access Memory), ROM (Read Only Memory), and SSD (Solid State Drive). The SSD stores an OS (Operating System), application programs, and various data. The OS and application programs are deployed in the RAM and executed by the CPU. In FIG. 1, the inside of the control device 10 is shown as blocks, with functions realized by application programs, etc.

The output interface 40 displays the measurement data and the calculation results of the calculation device 30 (e.g., the scoring results). The output interface 40 can be configured, for example, with an analog tester, a digital tester, and a display. In addition, when the measurement data and the calculation results are output as sound, the output interface 40 can be configured with a speaker or earphones.

The measurement data includes the current, voltage, and amount of welding material supplied to the welding torch 2, the position, posture, and movement of the welding torch 2 measured by the sensor 6, and the operation of the welding torch 2 measured by the measurement device 7. If the measurement device 7 is configured to include a camera, the measurement data can include video data from the camera. The output interface 40 may display the data obtained by the control device 10 as the measurement data, or may display data with the sampling rate or image quality adjusted as necessary.

As the scoring result, the scoring results of the measured operation parameters (parameters representing the welding operation) of the welding operator 50 are displayed. As the scoring result, the output interface 40 may display the scoring results of all operation parameters in a visualized form such as a radar chart, or may display the scoring results of each operation parameter numerically.

The calculation device 30 includes a weld angle calculation unit 31, an ideal motion data generation unit 33, a database 32, a database 35, and a welding motion evaluation unit 34. The database 32 and the database 35 may be configured as a single database.

The weld angle calculation unit 31 calculates and obtains the weld angle 5. The weld angle 5 is the angle of the surface of the weld of the workpiece 3 relative to a reference plane (e.g., a horizontal plane), so the weld angle calculation unit 31 can calculate the weld angle 5 from the measurement data (e.g., the position, posture, and movement of the welding torch 2 measured by the sensor 6, and the operation of the welding torch 2 measured by the measurement device 7) and the shape and position of the workpiece 3 input in advance. Note that when the weld angle calculation unit 31 calculates the weld angle 5, the user does not need to input the weld angle 5 through the input interface 20.

The ideal motion data generating unit 33 inputs the weld angle 5 input by the input interface 20 or the weld angle 5 calculated by the weld angle calculating unit 31, and generates ideal motion data for this weld angle 5 using multiple reference data stored in the database 35. The ideal motion data is data about the ideal welding motion of the welding operator 50, i.e., the welding motion that the welding operator 50 aims to achieve. For example, the ideal motion data includes a target value and standard deviation that are targets for the welding motion. The ideal motion data generating unit 33 stores the generated ideal motion data in the database 32.

The database 35 stores multiple reference data. The reference data is data that is arbitrarily determined in advance according to the welding position and serves as a reference for the welding operation. In this embodiment, four reference data are used, as described below. The reference data includes the target values and standard deviations of each operation parameter in each welding position as reference data.

The welding action evaluation unit 34 scores the welding action of the welding operator 50 for each action parameter based on a scoring algorithm and ideal action data. The welding action evaluation unit 34 can determine the welding action (action parameters) of the welding operator 50 from the action of the welding torch 2 of the welding operator 50 measured by the measuring device 7, or the current, voltage, and amount of welding material supplied to the welding torch 2. The welding action evaluation unit 34 transmits the scoring results to the output interface 40.

Figure 2 is a diagram showing an example of the measurement data and the scoring results displayed on the output interface 40. In the welding conditions section of Figure 2, the average current value, voltage value, welding speed, and heat input obtained by measurement are displayed as the measurement data. In the time series data section, the welding conditions and the movement of the torch are displayed over the elapsed time. In the video section, a video of the welding operation of the welding operator 50 captured by the measuring device 7 equipped with a camera is displayed. In the scoring data section, the results of the welding operation evaluation unit 34 scoring the operation parameters indicating the welding conditions, the movement of the torch, etc. are displayed in a radar chart.

The items shown in FIG. 2 are examples of items that may be displayed. In addition to the items shown in FIG. 2, the output interface 40 may also display data on welding characteristics, data obtained by calculating the characteristics, and the like.

Figure 3 is a flowchart of the process of scoring the welding operation of a welding operator 50, which is executed by the welding operation evaluation system according to this embodiment. Typical operation parameters to be scored include the welding speed, welding torch angle, welding torch height, current value, and voltage value. In the following, the welding speed will be used as an example of the operation parameter to be scored.

In step S00, the control device 10 starts the scoring process of the welding operation of the welding operator 50. The scoring process of the welding operation is performed after the welding operator 50 has finished the welding operation. However, if the weld angle 5 is known in advance and has been input to the control device 10 as a set value, the scoring process can also be performed while the welding operator 50 is performing the welding operation.

In step S01, the control device 10 inputs the scoring section specified by the user. The user operates the input interface 20 to specify the scoring section. The scoring section is the time range in which the calculation device 30 will score the welding action. For example, if a welding worker 50 performs welding for a total of 45 seconds and the user wishes to score the action from 5 seconds to 35 seconds of this time, the range "5 to 35 (seconds)" is specified as the scoring section. In this case, the length of time to be scored is 30 seconds (= 35 seconds - 5 seconds).

In general, special welding operations called start and end processing are often performed at the beginning and end of welding. When scoring the welding operations of welding operator 50, it is desirable to score the operations excluding the start and end processing operations.

In step S02, the control device 10 inputs the scoring interval specified by the user. The user operates the input interface 20 to specify the scoring interval. The scoring interval is the time interval (pitch) at which the calculation device 30 scores the welding operation in the scoring section. For example, if it is desired to perform scoring every 0.5 seconds, "2.0 (Hz)" is specified as the scoring interval. In this case, if the length of the scoring time is 30 seconds, the control device 10 performs scoring 60 times (= 30 seconds x 2.0 Hz). In other words, there are 60 scoring periods in the scoring section.

In step S03, the control device 10 inputs the scoring algorithm specified by the user. As described above, the control device 10 stores, for example, one or more scoring algorithms in advance, and the user can specify the scoring algorithm by selecting one from these. The user may also specify the scoring algorithm by inputting the scoring algorithm to the control device 10 via the input interface 20.

The scoring algorithm is a method for scoring the welding action of the welding operator 50. For example, when scoring the variation in the welding action, the welding action is scored according to the scoring algorithm using ideal action data including the target value and standard deviation of the action parameters. Hereinafter, the target value and standard deviation of the action parameters included in the ideal action data are referred to as the "target value of ideal action" and the "standard deviation of ideal action", respectively. The scoring algorithm is a standard that determines how to score the welding action (action parameters) using the target value of ideal action and the standard deviation of ideal action, and is closely related to the quality standards for welding and the training policy of the welding operator 50.

Figure 4 is a diagram showing an example of a scoring algorithm, and shows the relationship between the value of the motion parameter and the score of the motion parameter in scoring. In the scoring algorithm shown in Figure 4, when the value of the motion parameter is the target value G of the ideal motion, the score is 100 points, when the value of the motion parameter is larger or smaller than the target value G of the ideal motion by the standard deviation σ of the ideal motion, the score is 0 points, and when the value of the motion parameter is between these values, the score changes linearly from 100 points to 0 points. This scoring algorithm is suitable for scoring motions that have higher quality as the value of the motion parameter is closer to the target value G. Note that the scoring algorithm is not limited to the one shown in Figure 4, and can be determined arbitrarily, such as the one shown in Example 2, for example.

Return to the explanation of Figure 3.

In step S04, the control device 10 starts the scoring loop process. For example, if the scoring section is 5 to 35 seconds (the length of time to be scored is 30 seconds) and the scoring interval is 2.0 Hz, there are 60 scoring periods in the scoring section, and the control device 10 performs 60 scoring in the scoring section. Below, the processing in the nth loop will be explained assuming that the nth scoring period in the scoring section is being scored (i.e., the nth scoring out of 60 scorings has been performed).

In step S05, the weld angle calculation unit 31 of the control device 10 calculates the weld angle 5 in the nth scoring period. Hereinafter, the weld angle 5 in the nth scoring period may be referred to as the angle φn. As described above, the weld angle calculation unit 31 calculates the weld angle φn from the measurement data and the shape and position of the workpiece 3 input in advance, but the average value in the scoring period may be obtained as the weld angle φn, or the intermediate value in the scoring period may be obtained as the weld angle φn.

If the user inputs the weld angle φn as a set value into the control device 10, the process of step S05 can be omitted.

In step S06, the ideal motion data generating unit 33 of the control device 10 uses the weld angle φn to determine the contribution (weighting) of each of the multiple reference data stored in the database 35 to the motion parameters in the welding work of the welding operator 50. The contribution indicates the weighting of what proportion each of the multiple reference data accounts for in the motion parameters. The contribution of each of the reference data is determined by the weld angle φn.

The reference data is welding operation data that is arbitrarily determined in advance according to the welding position. The reference data includes the target value and standard deviation of each operation parameter in each welding position, and is stored in database 35. In this embodiment, as an example, four reference data are used, namely, overhead welding data (UD), downward welding data (DD), vertical welding data (VD), and horizontal welding data (HD). The overhead welding data, downward welding data, vertical welding data, and horizontal welding data are, for example, data of the target value and standard deviation of each operation parameter in overhead welding, downward welding, vertical welding, and horizontal welding, respectively. These target values and standard deviations are determined in advance.

Figure 5 is a diagram for explaining an example of a method for determining the contribution of each piece of reference data to an operating parameter, and shows the workpiece 3, the weld angle 5 (φn), and the welding torch 2. In the example shown in Figure 5, the weld angle φn is 60 degrees, as an example.

As shown in FIG. 5, the contribution of vertical welding data is calculated as VDsin(φn), and the contribution of flat welding data is calculated as DDcos(φn). In the example shown in FIG. 5, the contributions of overhead welding data and horizontal welding data are zero.

Return to the explanation of Figure 3.

In step S07, the ideal motion data generating unit 33 adds up the contributions of the reference data to the motion parameters to generate ideal motion data at the weld angle φn. The ideal motion data includes the target values and standard deviations of the motion parameters during the welding work of the welding operator 50 at the weld angle φn.

In the example shown in FIG. 5, the ideal operation data at the weld angle φn is
{VDsin(φn)+DDcos(φn)}/(sin(φn)+cos(φn))
For example, when the weld angle φn is 60 degrees, and the welding speed, which is an operation parameter, has a target value of 150 mm/min with a standard deviation of 30 mm/min in vertical welding data (VD) and a target value of 100 mm/min with a standard deviation of 20 mm/min in flat welding data (DD), the target value of the ideal operation is 132 mm/min and the standard deviation of the ideal operation is 26 mm/min.

In step S08, the welding action evaluation unit 34 scores each of the action parameters in the welding action of the welding operator 50 during the nth scoring period based on the scoring algorithm and the ideal action data. The action parameters of the welding operator 50 can be obtained from the action of the welding torch 2 measured by the measuring device 7, or the current, voltage, and amount of welding material supplied to the welding torch 2. Examples of the action parameters to be scored include the welding speed, welding torch angle, welding torch height, current value, and voltage value, as described above.

Figure 6 shows an example of scoring an operation parameter. In this embodiment, the operation parameter is the welding speed, and the scoring algorithm shown in Figure 4 is used. In the scoring algorithm, the target value of ideal operation is 132 mm/min, and the standard deviation of ideal operation is 26 mm/min. That is, when the welding speed is 132 mm/min, the score of the operation parameter is 100 points, when the welding speed is within the range of the standard deviation, the score changes linearly, and when the welding speed is outside the range of the standard deviation (158 mm/min or more or 106 mm/min or less), the score is 0 points.

The welding action evaluation unit 34 scores the welding speed of the welding operator 50 based on this scoring algorithm and the ideal action data. As shown in FIG. 6, if the welding speed of the welding operator 50 is 145 mm/min during the nth scoring period, the score is 50 points.

Return to the explanation of Figure 3.

In step S09, the welding action evaluation unit 34 determines whether or not scoring has been performed for all the scoring periods in the scoring section. In this embodiment, there are 60 scoring periods in the scoring section. Therefore, if n is less than 60, scoring has not been performed for all the scoring periods, so n is incremented by 1 (n becomes n+1) and the process returns to step S04. If n is 60, scoring has been performed for all the scoring periods, so the process of step S10 is performed.

When the processing of step S09 is completed, the generation of ideal motion data and the scoring of the motion parameters of the welding operator 50 are completed for all scoring periods in the scoring section.

In step S10, welding action evaluation unit 34 averages the scores of the action parameters in the scoring section for each action parameter. For example, if there are 60 scoring periods in a scoring section, and for an action parameter (welding speed), the score for the first scoring period is 40 points, the score for the second scoring period is 65 points, the score for the nth (3≦n≦59) scoring period is 50 points, and the score for the 60th scoring period is 80 points, the scores of the action parameters in the welding action of welding operator 50 are averaged as follows:
(40 + 65 + ... + 50 + ... 80) / 60
The welding action evaluation unit 34 transmits the scoring result to the output interface 40. Note that the welding action evaluation unit 34 may determine a scoring period during which the score of the action parameter is higher or lower than a predetermined reference value, without averaging the scores of the action parameter in the scoring section, and transmit the determined scoring period to the output interface 40 as the scoring result.

In step S11, the control device 10 ends the scoring process of the welding operation of the welding operator 50 since the scoring of each operation parameter has been completed.

The output interface 40 can display data and information obtained by the control device 10 through calculations and input, such as these scoring results and measurement data. The welding work evaluation system according to this embodiment can effectively train the welding operator 50 by visualizing and displaying such data and information. In addition, such data and information is automatically stored in the database 32, and can also be used for future training of the welding operator 50.

The welding work evaluation system according to this embodiment has the above configuration and can easily evaluate welding work skills.

Figure 7 is a schematic diagram showing the configuration of a welding work evaluation system according to Example 2 of the present invention and the welding work of a welding worker 50. The welding worker 50 is performing pipe welding, which is often seen in on-site welding at factory plants, etc.

The welding work evaluation system according to this embodiment includes a motion capture device 12, a data logger 8, and a control device 10, and evaluates the welding work skills (welding skills) of a welding worker 50. The devices shown in FIG. 7, for example, the digital welding machine 1, the motion capture device 12, the data logger 8, and the control device 10, are connected to each other via a communication network such as a wireless LAN or a wired LAN.

In this embodiment, the workpiece 3 is a cylindrical member such as a pipe. As an example, the welding worker 50 welds the workpiece 3 horizontally to a vertical fixed wall 9.

A number of markers 11 coated with reflective material are attached near the tip of the welding torch 2 as sensors that respond to the motion capture device 12.

The motion capture device 12 is installed around the fixed wall 9 around the working position of the welding operator 50, and is a measuring device that measures the position of the marker 11 on the welding torch 2. The motion capture device 12 corresponds to the measuring device 7 (FIG. 1) in the first embodiment, and measures the movement of the welding torch 2 based on the position of the marker 11. The motion capture device 12 detects the three-dimensional position of the welding torch 2 based on the light reflected from the marker 11 on the welding torch 2, and can obtain the movement and angle of the tip of the welding torch 2 in detail. The motion capture device 12 can thereby identify the position and angle (tilt) of the welding torch 2 relative to the material to be welded 3.

In addition, FIG. 7 shows, as an example, a configuration in which the welding work evaluation system according to this embodiment is equipped with two motion capture devices 12. The number of motion capture devices 12 equipped in the welding work evaluation system according to this embodiment may be one or three or more. When three or more motion capture devices 12 are installed, it is possible to improve the measurement accuracy and widen the measurement range.

The control device 10 in this embodiment has a configuration similar to that of the control device 10 in the first embodiment (FIG. 1). However, the weld angle 5 is not included in the set values input by the input interface 20 (i.e., the user does not input the weld angle 5). The weld angle 5 is calculated by the weld angle calculation unit 31. In addition, the shape and position (spatial coordinates of the position to be welded) of the workpiece 3, which is a cylindrical member, are input in advance by the user, and the control device 10 stores these.

The flowchart of the scoring process of the welding operation of the welding operator 50 performed by the welding work evaluation system according to this embodiment is the same as that shown in FIG. 3. Below, the scoring process performed by the welding work evaluation system according to this embodiment will be described, focusing mainly on the differences from the points described in the first embodiment.

In this example, the welding worker 50 welds the cylindrical workpiece 3 to a fixed wall 9, and the welding worker 50 performs the process of welding from a vertical position upward to a downward position over a period of 75 seconds.

In step S00 of FIG. 3, the control device 10 starts the process of scoring the welding operation of the welding operator 50. The process of scoring the welding operation is performed after the welding operation of the welding operator 50 is completed.

In step S01, the control device 10 inputs the scoring section specified by the user. For example, if the welding worker 50 performs welding for a total of 75 seconds and the user wishes to score the actions from 10 seconds to 70 seconds of this time, the user specifies the range "10 to 70 (seconds)" as the scoring section. In this case, the length of time to be scored is 60 seconds (= 70 seconds - 10 seconds).

In step S02, the control device 10 inputs the scoring interval specified by the user. For example, if scoring is to be performed every 5 seconds, "0.2 (Hz)" is specified as the scoring interval. In this case, if the length of time to be scored is 60 seconds, the control device 10 performs scoring 12 times (= 60 seconds x 0.2 Hz). In other words, there are 12 scoring periods in the scoring section.

In step S03, the control device 10 inputs the scoring algorithm specified by the user. In this embodiment, the control device 10 is provided with three scoring algorithms, and the user specifies the scoring algorithm by selecting one of them.

Figures 8A, 8B, and 8C are diagrams showing an example of a scoring algorithm in this embodiment, and show the relationship between the values of the motion parameters and the scores of the motion parameters in scoring.

The scoring algorithm shown in Figure 8A is the same as the scoring algorithm shown in Figure 4.

In the scoring algorithm shown in FIG. 8B, when the value of the operation parameter is the target value G of the ideal operation, the score is 100 points, when the value of the operation parameter is greater or less than the target value G of the ideal operation by the standard deviation σ of the ideal operation, the score is 0 points, when the value of the operation parameter is greater or less than the standard deviation σ of the ideal operation, the score is -100 points, and when the value of the operation parameter is between these values, the score changes linearly from 100 points to -100 points. This scoring algorithm is used in cases where a large deviation of the value of the operation parameter from the target value G causes quality defects, and is suitable for scoring when it is desired to set prohibited operations for the welding operator 50.

In the scoring algorithm shown in FIG. 8C, if the value of the operation parameter is the target value G of the ideal operation, the score is 100 points, if the value of the operation parameter is greater or less than the target value G of the ideal operation by the standard deviation σ of the ideal operation, the score is 0 points, and if the value of the operation parameter is between these values, the score is 100 points. This scoring algorithm is suitable for scoring cases where the value of the operation parameter deviates from the target value G, but is within the range included in the standard deviation σ, there is no significant difference in quality and no quality defects will occur.

In this example, it is assumed that the user selects the scoring algorithm shown in Figure 8A.

Return to the explanation of Figure 3.

In step S04, the control device 10 starts the scoring loop process. For example, if the scoring section is 10 to 70 seconds (the length of time to be scored is 60 seconds) and the scoring interval is 0.2 Hz, there are 12 scoring periods in the scoring section, and the control device 10 performs 12 scoring in the scoring section. Below, the processing in the nth loop will be explained assuming that the nth scoring period in the scoring section is being scored (i.e., the nth scoring out of 12 scorings is being performed).

In step S05, the weld angle calculation unit 31 of the control device 10 calculates the weld angle φn for the nth scoring period.

Here, we will use Figure 9 to explain how to calculate the weld angle φn in this example.

Figure 9 is a diagram for explaining an example of a method for calculating the weld angle φn in this embodiment, and shows the workpiece 3, the weld angle 5 (φn), and the welding torch 2. As described above, the control device 10 stores in advance the shape and position (spatial coordinates of the position to be welded) of the workpiece 3.

In the following, for ease of understanding, it is assumed that the X-axis (horizontal axis) and Y-axis intersect at the position of the central axis of the cylindrical workpiece 3, and that the outer circumferential radius of the workpiece 3 is R. It is also assumed that the coordinates (Xn, Yn) of the position of the tip of the welding torch 2 are measured by the motion capture device 12.

The outer circumferential radius R of the workpiece 3 is
R=√(Xn^2+Yn^2) (1)
This is expressed as:

Pipe welding is performed along the outer periphery of the pipe. Therefore, while the workpiece 3, which is a cylindrical member such as a pipe, is being welded, the tip of the welding torch 2 is always located on the outer periphery of the workpiece 3. Therefore, the weld angle φn is the angle between the tangent to the outer periphery of the workpiece 3 at the tip of the welding torch 2 and the X-axis (horizontal axis), as shown in Figure 9. Geometrically,
sin(φn)=R/Xn (2)
This is expressed as:

From equations (1) and (2), the weld angle φn can be calculated by the following equation.
φn=arcsin(√(Xn^2+Yn^2)/Xn) (3)
The weld angle calculation unit 31 calculates the weld angle φn from equation (3) using the coordinates (Xn, Yn) of the tip of the welding torch 2 measured by the motion capture device 12.

If the outer radius R of the workpiece 3 is known, formula (3) may include R; however, since the outer radius R increases with the build-up of welds, it is preferable to determine the weld angle φn from the coordinates (Xn, Yn) of the tip of the welding torch 2. Furthermore, if the marking interval (sampling frequency of marking) is large, the weld angle φn changes gradually during the marking period, so it is preferable to use a representative value during this marking period as the weld angle φn. For example, in this embodiment, the average value of the weld angle φn is used as the representative value during the marking period.

Return to the explanation of Figure 3.

In step S06, the ideal motion data generating unit 33 of the control device 10 uses the weld angle φn to determine the contribution (weighting) of each of the multiple reference data stored in the database 35 to the motion parameters in the welding work of the welding operator 50. The contribution of each of the reference data is determined by the weld angle φn.

In step S07, the ideal motion data generating unit 33 adds up the contributions of the reference data to the motion parameters to generate ideal motion data at the weld angle φn. The ideal motion data includes the target values and standard deviations of the motion parameters during the welding work of the welding operator 50 at the weld angle φn.

The ideal operation data at the weld angle φn is, as in Example 1,
{VDsin(φn)+DDcos(φn)}/(sin(φn)+cos(φn))
For example, if the weld angle φn is 60 degrees, and the welding speed, which is an operation parameter, has a target value of 150 mm/min with a standard deviation of 15 mm/min in vertical welding data (VD) and a target value of 100 mm/min with a standard deviation of 30 mm/min in flat welding data (DD), the target value of the ideal operation is 132 mm/min and the standard deviation of the ideal operation is 20 mm/min.

In step S08, the welding action evaluation unit 34 scores each action parameter in the welding operation of the welding operator 50 during the nth scoring period based on the scoring algorithm and the ideal action data.

Figure 10 is a diagram showing an example of scoring of an operation parameter. In this embodiment, the operation parameter is the welding speed, and the scoring algorithm shown in Figure 8A is used. In the scoring algorithm, the target value of ideal operation is 132 mm/min, and the standard deviation of ideal operation is 20 mm/min. That is, when the welding speed is 132 mm/min, the score of the operation parameter is 100 points, when the welding speed is within the range of the standard deviation, the score changes linearly, and when the welding speed is outside the range of the standard deviation (152 mm/min or more or 112 mm/min or less), the score is 0 points.

The welding action evaluation unit 34 scores the welding speed of the welding operator 50 based on this scoring algorithm and the ideal action data. As shown in FIG. 10, if the welding speed of the welding operator 50 in the nth scoring period is 122 mm/min, the score is 50 points.

Return to the explanation of Figure 3.

In step S09, the welding action evaluation unit 34 determines whether or not scoring has been performed for all the scoring periods in the scoring section. In this embodiment, there are 12 scoring periods in the scoring section. Therefore, if n is less than 12, scoring has not been performed for all the scoring periods, so n is incremented by 1 (n becomes n+1) and the process returns to step S04. If n is 12, scoring has been performed for all the scoring periods, so the process of step S10 is performed.

When the processing of step S09 is completed, the generation of ideal motion data and the scoring of the motion parameters of the welding operator 50 are completed for all scoring periods in the scoring section.

Figure 11A is a diagram showing an example of ideal operation data generated in this embodiment. In this embodiment, the scoring section is 10 to 70 seconds (the length of time scored is 60 seconds) and the scoring interval is 0.2 Hz, so there are 12 scoring periods in the scoring section and 12 scorings are performed. Figure 11A shows the target value G and standard deviation σ of the operation parameter (welding speed) generated during this 60-second scoring time. In Figure 11A, the horizontal axis indicates the passage of time and the vertical axis indicates the welding speed. During this 60-second scoring time, welding is performed with the welding position angle θ (Figure 9) ranging from 0 degrees to 90 degrees.

Figure 11B shows the ideal motion data shown in Figure 11A, along with the value P of the motion parameter (welding speed) in the welding operation of welding operator 50 and the score S, which is the scoring result. The closer the welding speed value P of welding operator 50 is to the target value G, the higher the score S will be, and the further away the value P is from the target value G, the lower the score S will be, and when the value P is outside the range of the standard deviation σ, the score S will be 0 points.

Return to the explanation of Figure 3.

In step S10, welding action evaluation unit 34 averages the scores of the action parameters in the scoring section for each action parameter. An example shown in Fig. 11A and Fig. 11B will be described. As shown in Fig. 11A and Fig. 11B, there are 12 scoring periods in the scoring section. The scores of the action parameters (welding speed) in the welding action of welding operator 50 are averaged for these 12 scoring periods as follows.
(57 + 53 + 0 + 83 + 55 + 85 + 28 + 58 + 86 + 52 + 33 + 21) / 12
That is, the welding speed score of the welding operator 50 in this scoring section is 51 points.

In addition, the welding operation evaluation unit 34 may determine the scoring periods during which the scores of the operation parameters are higher or lower than a predetermined reference value, without averaging the scores of the operation parameters in the scoring sections, and transmit the determined scoring periods to the output interface 40 as the scoring results.

In step S11, the control device 10 ends the scoring process of the welding operation of the welding operator 50 since the scoring of each operation parameter has been completed.

The output interface 40 can display data and information obtained by the control device 10 through calculations and input, such as these scoring results and measurement data. The welding work evaluation system according to this embodiment can effectively train the welding operator 50 by visualizing and displaying such data and information. In addition, such data and information is automatically stored in the database 32, and can also be used for future training of the welding operator 50.

The welding work evaluation system according to this embodiment has the above configuration and can easily evaluate welding work skills in the same way as the welding work evaluation system according to Example 1.

The present invention is not limited to the above-mentioned examples, and various modifications are possible. For example, the above-mentioned examples have been described in detail to clearly explain the present invention, and the present invention is not necessarily limited to an embodiment that includes all of the configurations described. It is also possible to replace part of the configuration of one example with the configuration of another example. It is also possible to add the configuration of another example to the configuration of one example. It is also possible to delete part of the configuration of each example, or to add or replace other configurations.

1...digital welding machine, 2...welding torch, 3...workpiece, 4...welding bead, 5...welding angle, 6...sensor, 7...measuring device, 8...data logger, 9...fixed wall, 10...control device, 11...marker, 12...motion capture device, 20...input interface, 30...arithmetic unit, 31...welding angle calculation unit, 32...database, 33...ideal motion data generation unit, 34...welding motion evaluation unit, 35...database, 40...output interface, 50...welding operator.

Claims (3)

A measuring device for measuring the movement of a welding torch held by a welding operator who welds a workpiece;
A database storing multiple reference data;
an ideal motion data generating unit that generates ideal motion data at a weld angle using a plurality of the reference data;
a welding action evaluation unit that scores the welding action of the welding operator obtained from the action of the welding torch measured by the measurement device based on a scoring algorithm and the ideal action data;
A weld angle calculation unit that calculates the weld angle;
Equipped with
The reference data is data of a welding operation that is arbitrarily determined according to a welding position, and includes operation parameters in the welding position.
The weld angle is an angle of a surface of the weld of the workpiece relative to a predetermined reference plane,
The ideal motion data is data regarding a welding motion targeted by the welding operator, and includes the motion parameters in the welding operation of the welding operator at the weld angle,
The scoring algorithm is a method for scoring the welding action of the welding operator,
the weld angle calculation unit calculates the weld angle during a marking period in which marking is performed based on the movement of the welding torch measured by the measurement device and the shape of the welded material input in advance,
the ideal motion data generating unit uses the weld angle to obtain a contribution degree, which is a weighting of the motion parameter in the welding work of the welding operator, for each of the plurality of reference data, and adds up the contribution degrees to generate the ideal motion data for the weld angle;
The contribution is determined by the weld angle,
The welding action evaluation unit scores the action parameters in the welding action of the welding operator based on the scoring algorithm and the ideal action data during the scoring period.
A welding work evaluation system comprising: Equipped with an input interface,
The scoring algorithm is specified by a user operating the input interface.
The welding operation evaluation system according to claim 1 . The welding torch includes a marker;
The measuring device is a motion capture device that measures the position of the marker and measures the movement of the welding torch based on the position of the marker.
The welding operation evaluation system according to claim 1 .

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