JP2019155425A - Arc-welding support device, arc-welding support method and program - Google Patents

Abstract

To provide an arc-welding support device and the like which can derive movement speed of a welding torch with good accuracy.SOLUTION: An arc-welding support device 1 comprises: a photographing part 11 that is arranged in a welding torch 2 so that a movement direction of the welding torch 2 during arc-welding work is included in a view angle thereof; a speed deriving part 12 that derives movement speed of the welding torch 2 on the basis of an image photographed by the photographing part 11; and a signal output part 12 that outputs a predetermined signal when the movement speed derived by the speed deriving part 12 deviates from a predetermined speed range.SELECTED DRAWING: Figure 2

Description

  The present invention relates to an arc welding support apparatus, an arc welding support method, and a program.

  In arc welding such as non-consumable electrode arc welding, consumable electrode arc welding, and plasma arc welding, the welding speed, which is the moving speed of the welding torch, is appropriate when the base metal plate thickness, joint shape, welding method, etc. are set. The value is determined. In the case of manual welding in which the welding operator grips the welding torch by hand, the welding operator needs to move the welding torch so that the appropriate value is obtained. It is difficult to perform welding while maintaining the speed at an appropriate value.

  On the other hand, the arc welding apparatus described in Patent Document 1 is provided with a three-axis acceleration sensor in the welding torch, integrates the acceleration signals of each axis from the sensor, and synthesizes these integration signals to move the welding torch. Calculate the speed signal. When the value of the moving speed signal in the steady state is outside the predetermined speed range, an alarm is generated to assist the welding operator in maintaining the moving speed of the welding torch within an appropriate range.

JP2013-223879A

  However, when the welding speed is low, the accuracy of the acceleration value output by the three-axis acceleration sensor is deteriorated. Therefore, it is difficult to accurately derive the moving speed of the welding torch depending on the arc welding apparatus of Patent Document 1. Thus, there are problems such as generating false alarms.

  This invention is made | formed in view of such a situation, The objective is to provide the arc welding assistance apparatus etc. which can derive | lead-out the moving speed of a welding torch accurately.

  An arc welding support apparatus according to an aspect of the present disclosure is based on an imaging unit provided in the welding torch so that the viewing angle includes the moving direction of the welding torch during arc welding work, and an image captured by the imaging unit. A speed deriving unit for deriving a moving speed of the welding torch; and a signal output unit for outputting a predetermined signal when the moving speed derived by the speed deriving unit is out of a predetermined speed range.

  In this aspect, since the moving speed of the welding torch is derived based on the image captured by the imaging unit, the moving speed of the welding torch is accurately derived even when the moving speed of the welding torch is low. Can do.

  In the arc welding support apparatus according to an aspect of the present disclosure, the speed deriving unit has acquired the first image and an image acquisition unit that acquires a second image captured after a predetermined time has elapsed since the first image was captured. A stationary object identifying unit that identifies a stationary object based on the first image and the second image, and based on a variation amount of the stationary object between the first image and the second image and the predetermined time. To derive the moving speed.

  In this aspect, the stationary object is identified based on the first image and the second image captured after a lapse of a predetermined time from the time of capturing the first image, and based on the variation amount of the identified stationary object and the predetermined time. Since the moving speed is derived, the moving speed of the welding torch can be accurately derived.

  In the arc welding support apparatus according to an aspect of the present disclosure, the imaging unit is a stereo camera, and the speed deriving unit derives a distance between the stationary object and the welding torch based on an image captured by the stereo camera. A distance deriving unit is included, and the moving speed is derived based on a stationary object whose distance from the welding torch is within a predetermined distance among the identified plurality of stationary objects.

  In this aspect, based on the image captured by the stereo camera, the distance between the stationary object and the welding torch is derived, and the moving speed is derived based on the stationary object whose distance from the welding torch is within a predetermined distance. The moving speed of the welding torch can be derived with high accuracy.

  In the arc welding support apparatus according to an aspect of the present disclosure, the plurality of identified stationary objects include a temporary welded portion or an end portion of a weld line, and the speed deriving unit includes the temporary welded portion or the weld line. The moving speed is derived based on the end point portion.

  In this aspect, since the moving speed is derived based on the temporarily fixed welded portion or the end portion of the weld line, the moving speed of the welding torch can be accurately derived using a specific shape at the welding site.

  An arc welding support method according to one aspect of the present disclosure includes a movement of the welding torch based on an image that is provided in the welding torch so as to include a moving direction of the welding torch in an arc welding operation and captured by an imaging unit. A speed is derived, and when the derived moving speed is out of a predetermined speed range, a predetermined signal is output.

  In this aspect, since the moving speed of the welding torch is derived based on the image captured by the imaging unit, an arc that accurately derives the moving speed of the welding torch even when the moving speed of the welding torch is low. A welding support method can be provided.

  The program according to an aspect of the present disclosure acquires an image captured by an imaging unit provided in the welding torch so that the viewing angle includes the moving direction of the welding torch during arc welding work in a computer, and the acquired image Based on this, the moving speed of the welding torch is derived, and when the derived moving speed is out of a predetermined speed range, a process of outputting a predetermined signal is executed.

  In this aspect, the computer can function as an arc welding support device that accurately derives the moving speed of the welding torch even when the moving speed of the welding torch is low.

  An arc welding support apparatus according to an aspect of the present disclosure includes an imaging unit provided to include a welding torch and a welded portion of a base material in a viewing angle, and movement of the welding torch based on an image captured by the imaging unit A speed deriving unit for deriving a speed; and a signal output unit for outputting a predetermined signal when the moving speed derived by the speed deriving unit is out of a predetermined speed range.

  In this aspect, since the imaging unit is provided to include the welding torch and the welded portion of the base material in the viewing angle, the weight of the welding torch is reduced and the load on the welder is reduced. The moving speed of the welding torch can be derived well.

  An arc welding support device and the like that can accurately derive the moving speed of the welding torch can be provided.

It is a schematic diagram which shows an example of a welding torch provided with the arc welding assistance apparatus which concerns on Embodiment 1. FIG. It is a block diagram which shows one structural example of the arc welding assistance apparatus (monocular camera) which concerns on Embodiment 1. FIG. It is explanatory drawing regarding derivation | leading-out of the moving speed by an arc welding assistance apparatus. 4 is a flowchart illustrating a processing procedure (main) of a calculation unit according to the first embodiment. 3 is a flowchart illustrating a processing procedure (subroutine) of a calculation unit according to the first embodiment. It is a block diagram which shows one structural example of the arc welding assistance apparatus (stereo camera) which concerns on Embodiment 2. FIG. 10 is a flowchart illustrating a processing procedure of a calculation unit according to the second embodiment. It is explanatory drawing regarding the brightness | luminance of a temporarily fixed welding part. It is explanatory drawing regarding derivation | leading-out of the distance with a temporarily fixed welding part. It is a block diagram which shows one structural example of the arc welding assistance apparatus (camera in another housing | casing) which concerns on the modification 1. FIG.

(Embodiment 1)
Hereinafter, the present invention will be described in detail with reference to the drawings illustrating embodiments thereof. FIG. 1 is a schematic diagram illustrating an example of a welding torch 2 including an arc welding support device 1 according to the first embodiment. FIG. 2 is a block diagram illustrating a configuration example of the arc welding support apparatus 1 (monocular camera) according to the first embodiment.

  The arc welding support device 1 is fixed to the upper surface of the torch holder 22 of the welding torch 2 and is provided so that the viewing angle (viewing direction) of the imaging unit 11 described later faces the torch body 21 side. The welding torch 2 includes a cylindrical torch main body 21 in which an arc is generated, a torch holder 22 carried by a welder, and a torch switch 23.

  The welding torch 2 is connected to a welding power source device 4 (see FIG. 10). When the torch switch 23 is turned on, a welding voltage from the welding power source device 4 is applied to an electrode (not shown), Arc discharge is performed between the electrode and the base material 3 (see FIG. 3).

  As shown in FIG. 2, the arc welding support apparatus 1 includes an imaging unit 11, a calculation unit 12 for processing an image captured by the imaging unit 11, a storage unit 13, and a notification unit 14. The imaging unit 11, the calculation unit 12, the storage unit 13, and the notification unit 14 are connected by an internal bus 15 so as to communicate with each other.

  The imaging unit 11 includes a lens 111, an image sensor 112, and an AD conversion unit 113, and is a camera using a monocular lens, for example. The lens 111 is an optical lens such as a convex lens.

  The image sensor 112 is disposed in the casing of the arc welding support apparatus 1 so as to be the focal position of the lens 111. The image sensor 112 is, for example, a CMOS (Complementary Metal Oxide Semiconductor) sensor or the like, receives light incident from the lens 111, captures the light received by a plurality of pixels, and captures the captured image by AD conversion. Output to the unit 113. The number of pixels of the image sensor 112 and the pitch of the pixels are appropriately determined according to the resolution of the image to be captured.

  The AD conversion unit 113 divides and samples the input image (analog signal) at regular time intervals, quantizes the sampled value so that it can be converted into a digital signal, and the quantized value is a binary number designated in advance. Output in the number of digits. For the AD conversion unit 113, a flash type, a pipeline type, or the like is appropriately determined according to the sampling rate and resolution.

  The arithmetic unit 12 is configured by a CPU (Central Processing Unit), an MPU (Micro Processing Unit), or the like, and has a clock function. The arithmetic unit 12 reads out and executes the program 131P and data stored in advance in the storage unit 13, thereby performing various control processes and arithmetic processes. The arithmetic unit 12 stores the image data and the like in the storage unit 13 when processing data (image data) related to the image.

  The storage unit 13 includes a non-volatile memory such as a ROM (Read Only Memory), an EEPROM (Electrically Erasable Programmable ROM), a flash memory, or a volatile memory such as a RAM. It is memorized beforehand. The program 131P stored in the storage unit 13 may be a program 131P read from the recording medium 131 readable by the calculation unit 12. Alternatively, the program 131P may be downloaded from an external computer (not shown) connected to a communication network (not shown) and stored in the storage unit 13.

  The notification unit 14 includes, for example, a speaker, a rotation lamp, and a display display, and notifies the welder based on a predetermined signal output from the calculation unit 12.

  The arc welding support apparatus 1 has a speed deriving unit and a signal output unit. The speed deriving unit derives the moving speed of the welding torch 2 based on the image captured by the image capturing unit 11, and includes an image acquisition unit, a stationary object specifying unit, and a distance deriving unit. The computing unit 12 functions as a speed deriving unit by executing the program 131P. The signal output unit outputs a predetermined signal to the notification unit 14 when the derived moving speed of the welding torch 2 is out of a predetermined speed range. The calculation unit 12 functions as a signal output unit by executing the program 131P. When the calculation unit 12 functions as a speed deriving unit and a signal output unit, processing related to execution of the program 131P will be described with reference to a flowchart described later.

  In the present embodiment, the imaging unit 11 is provided in the casing of the arc welding support apparatus 1, and the imaging unit 11 and the calculation unit 12 are connected by an internal bus 15, and the imaging unit 11 and the calculation unit 12 are integrated. However, the present invention is not limited to this. The arc welding support device 1 is configured such that the imaging unit 11, the calculation unit 12, the storage unit 13, and the notification unit 14 are configured as separate bodies, and a casing that houses the imaging unit 11 is provided in the welding torch 2. Good. In this case, the housing that houses the imaging unit 11 is provided with a communication unit for communicating with the arithmetic unit 12 provided as a separate body, and data regarding the image output from the AD conversion unit 113 of the imaging unit 11 is Then, it is transmitted to the calculation unit 12 via the communication unit. The communication unit includes wired communication such as a serial cable and wireless communication such as WiFi (registered trademark).

  FIG. 3 is an explanatory diagram relating to the derivation of the moving speed by the arc welding support apparatus 1. In the explanatory view of FIG. 3, two base materials 3 are arranged side by side on a flat base, and a welded line 31 is formed by bringing the linear welded portions 31 of the base materials 3 into contact with each other. A plurality of temporarily welded portions (temporarily secured points) 32 are provided on the weld line. That is, when arc welding is started, the welded portions 31 of each of the base materials 3 are temporarily attached at a plurality of locations. Spot welding is used as a stop.

  The welding torch 2 carried by the welder is moved along the weld line from the near side on the paper surface. The imaging unit 11 is provided so that the viewing direction faces the torch main body 21. Preferably, at the time of welding work, any temporary fixing welded portion 32 or the end of the weld line has a viewing angle (viewing range). It is provided to be included in. That is, it is desirable that the image pickup unit 11 is provided so as to be able to pick up an image of one of the temporarily welded portions 32 or the end of the weld line until the welder starts and completes arc welding. . The terminal ends of these temporary fixing welds 32 or weld lines are extracted by the calculation unit 12 as stationary objects described later. The stationary object is not limited to the temporarily welded portion 32 or the end of the weld line, but is a fluorescent lamp, a door, or an equipment included in the welding power source device 4 or the like provided at the welding site, or an environmental scene at the welding site. It may be a window or the like.

  FIG. 4 is a flowchart illustrating a processing procedure (main) of the calculation unit 12 according to the first embodiment. FIG. 5 is a flowchart illustrating a processing procedure (subroutine) of the calculation unit 12 according to the first embodiment. The calculation unit 12 of the arc welding support apparatus 1 starts the processing shown below by executing the program 131P stored in the storage unit 13. For example, the calculation unit 12 may execute the program 131P when the torch switch 23 of the welding torch 2 is turned on.

  The calculation unit 12 configures an image (stationary object data) of the first stationary object (S01). The processing of S01 is executed by the arithmetic unit 12 as processing of a subroutine shown in FIG.

  The calculation unit 12 acquires the image data output from the imaging unit 11, and selects a set of two feature points from two consecutive images (S101). The image data output from the imaging unit 11 includes the environmental scenery at the welding site. The environmental scenery at the welding site includes the part 31 to be welded of the base material 3 or the equipment disposed around the base material 3 as described above. When the image data output from the imaging unit 11 is a moving image, the image data is constituted by image frames (continuous frames) of continuous still images captured with a predetermined resolution.

  The calculation unit 12 acquires two images (image 1 and image 2) that are continuously captured. The image 2 is the next frame of the image 1, and the imaging time of the image 1 corresponds to (t + 1) with respect to the imaging time (t) of the image 1. This +1 means the next frame.

  The calculation unit 12 uses a set of feature points based on the luminance amount (image 1: (p0, p1,... Pn), image 2: (p′0, p′1,... p′n)) are derived, and the set of these feature points is stored in the storage unit 13. The computing unit 12 selects two sets of corresponding feature points from the set of feature points. For example, the calculation unit 12 selects (p0, p1) of image 1 and (p′0, p′1) of image 2, and matches the sum of the respective luminance amounts (p0 + p1, p′0 + p′1). If it is set as a score and the matching score is a predetermined amount or more, it is determined that the set of selected feature points matches. In the following description, assuming that (p0, p1) of image 1 and (p′0, p′1) of image 2 are matched pairs, the calculation unit 12 selects a pair of two feature points. .

  The computing unit 12 calculates a vector of the two selected feature points (S102). Based on the combination of the two feature points selected in the processing of S101, the calculation unit 12 generates a vector (image 1: (V1 = p0-p1), image 2: (1) in each of the two images. V2 = p′0−p′1)) is calculated.

  The computing unit 12 determines whether the calculated two vectors are similar (S103). The calculation unit 12 compares the vectors (image 1: V1, image 2: V2) calculated in the process of S102, and determines the similarity of these vectors. For example, the calculation unit 12 performs the determination based on whether the absolute value of the difference between these vectors is within a predetermined value.

  If they are not similar (S103: NO), the calculation unit 12 performs a loop process to execute the process of S101 again. When executing S101 again, the calculation unit 12 excludes the feature point selected this time and newly selects a combination of two feature points from other feature points.

  If they are similar (S103: YES), the calculation unit 12 sets the two feature points (p0, p1) selected in the image 1 as position invariant points (S104). That is, the two selected feature points (p0, p1) are set as being part of a stationary object, and the calculation unit 12 sets, for example, a position invariant point flag or the like to the two feature points (p0, p1). In addition, it is stored in the storage unit 13. Similarly, the calculation unit 12 may set two feature points (p′0, p′1) selected in the image 2 as position invariant points.

  The computing unit 12 calculates the midpoint (vector centroid) of the two feature points (S105). The calculation unit 12 calculates the center point of the feature points of the two feature points selected in the image 1 and the image 2 as the center of gravity of the vector (image 1: VGG1 = (p0 + p1) / 2, image 2: VGG2 = (p′0 + p '1) / 2), and the center of gravity of these vectors is stored in the storage unit 13.

  The computing unit 12 deletes two feature points from the image data (S106). The calculation unit 12 derives a set of feature points from the image 1 and the image 2 in the process of S101. The calculation unit 12 deletes the feature points ((p0, p1), (p′0, p′1)) set as the position invariant points in S104 from each of the derived sets. The deletion of the feature points is not limited to deleting the feature point data itself. For example, the calculation unit 12 adds an exclusion flag to these feature points, for example, in the process of selecting the feature points thereafter. The feature points to which these exclusion flags are assigned may be excluded.

The calculation unit 12 selects each corresponding feature point from each image data (S107).
The calculation unit 12 determines other feature points other than the already selected feature points ((p0, p1), (p′0, p′1)) from the set of feature points from the image 1 and the image 2 derived in S101. (Image 1: p2, Image 2: p′2) is selected.

  The computing unit 12 calculates a vector between the feature point selected in S107 and the center of gravity of the previous vector (S108). Similarly to the processing of S108, the calculation unit 12 determines each vector in the image 1 and the image 2 (image 1: (V1 = p2-VG1)) based on the feature point selected in S107 and the center of gravity of the vector calculated last time. , Image 2: (V2 = p′2−VG2)).

  The calculation unit 12 determines whether or not the two vectors calculated in the same manner as the process of S103 are similar (S109).

  If they are similar (S109: YES), the selected feature points (p2, p'2) are set as position invariant points, and the center of gravity of the vector is calculated (S110). The calculation unit 12 sets the selected feature points (p2, p′2) as position invariant points in the same manner as the processing 104, and stores them in the storage unit 13.

  The calculation unit 12 calculates and calculates the center of gravity of the vector based on the midpoint between the feature point (p2, p′2) selected this time and the center of gravity (VG1, VG2) of the previously calculated vector, similarly to the processing of S108. The center of gravity of the vector is used in the subsequent processing. That is, the arithmetic unit 12 performs an overwriting process of the center of gravity of these vectors by performing substitution processing (VG1 ← (P2 + VG1) / 2, VG2 ← (P2 + VG2) / 2) on VG1 and VG2.

  If they are not similar (S109: NO), the calculation unit 12 skips the process of S110 and performs the process of S111. The calculation unit 12 deletes the feature points (p2, p'2) selected in S107 from each of the image data, similarly to the processing in S106 (S111).

  The calculation unit 12 determines whether all feature points have been selected (S112). The calculation unit 12 derives a set of feature points from each image in the process of S101, and determines whether or not each feature point stored as an array in the set has been selected, for example. Since the selected feature point is deleted from this array or a removal flag is given, the calculation unit 12 refers to the storage unit 13 to determine whether there is a feature point that has not yet been selected. Can do.

  When all the feature points are not selected (S112: NO), the calculation unit 12 performs a loop process to execute the process of S107 again. It goes without saying that the feature points selected in S107 are feature points that have not been selected in the processing so far. Therefore, by repeating the loop process of executing S107 again based on the determination process of S112, all feature points are selected, and based on the selected feature points and the center of gravity vector calculated in the process of the previous routine, Position invariant points are set sequentially.

  When all the feature points are selected (S112: YES), the calculation unit 12 configures a still object image (stationary object data) from the set position invariant points (S113). The computing unit 12 specifies a stationary object in the captured image based on the feature point set as a position invariant point, that is, configures a stationary object position image, and stores stationary object data related to the stationary object position image. 13 is stored. By constructing the position image of the stationary object in this way, it is possible to save a static feature value whose position does not change in the welding environment. The calculation unit 12 ends the process of the first stationary object data configuration (position invariant point extraction) which is a subroutine.

  The calculation unit 12 determines whether or not a predetermined time (ΔT) has elapsed (S02). The calculation unit 12 has a clock function and determines whether or not a predetermined time (ΔT) has elapsed. Alternatively, the calculation unit 12 may perform a standby process (sleep process) for a predetermined time (ΔT).

  When the predetermined time (ΔT) has not elapsed (S02: NO), the calculation unit 12 performs a loop process to perform the process of S02 again.

  When the predetermined time (ΔT) has elapsed (S02: YES), the computing unit 12 configures a second still object image (stationary object data) (S03). In the process of S03, as in the process of S01, the structure of stationary object data (position invariant point extraction) defined as a subroutine in FIG. 2 is performed. That is, for the process of S01, a stationary object is identified based on two consecutive images captured after the elapse of a predetermined time (ΔT), that is, a stationary object position image is formed, and the stationary object position image is related. The stationary object data is stored in the storage unit 13.

  The computing unit 12 derives the fluctuation amount (movement speed) (S04). The calculation unit 12 derives the moving speed of the welding torch 2 based on the first stationary object data stored in S01 and the second stationary object data stored in S012.

  The computing unit 12 compares the first stationary object data with the second stationary object data, and derives the fluctuation amount by matching the similarity of these data. The first stationary object data and the second stationary object data include data relating to the same stationary object, and the positions of these stationary objects on the image differ as the welding torch 2 is moved by the operation of the welder. It will be a thing. For example, the calculation unit 12 may derive the amount of displacement in pixel units between these stationary object data and perform similarity matching. Alternatively, the calculation unit 12 learns a variation amount based on the similarity or difference amount between these stationary object data in advance by machine learning or the like, and based on the learning data stored in the storage unit 13 as the learning result. The amount of variation may be derived.

  A plurality of stationary objects may be included in the first stationary object data and the second stationary object data. As shown in FIG. 3, when a plurality of temporary fixing welds 32 are provided along the welded portion 31 (welding line), the calculation unit 12 includes a welding torch among the plurality of temporary fixing welds 32. The temporary fixing weld portion 32 having the shortest distance to 2 may be a stationary object for deriving the amount of fluctuation. Since the distance to the welding torch 2 is based on the stationary object having the shortest distance, the fluctuation amount can be derived with high accuracy.

  Data relating to the shape or luminance amount of the temporary fixing weld 32 is stored in the storage unit 13 in advance, and the calculation unit 12 extracts the temporary fixing weld 32 in the captured image based on the data, and The distance between the temporarily welded portion 32 and another stationary object may be derived by using the welded portion 32 as a marker for image analysis. Note that the stationary object having the shortest distance from the welding torch 2 is not limited to the temporarily welded portion 32, and may be another stationary object.

  The computing unit 12 derives the moving speed of the welding torch 2 based on the derived fluctuation amount and the predetermined time (ΔT) in S02. Since the derived fluctuation amount has a correlation with the moving distance of the welding torch 2, the calculation unit 12 divides the moving distance determined based on the derived fluctuation amount by the predetermined time (ΔT) in S02. The moving speed of the welding torch 2 is derived.

  The calculation unit 12 determines whether or not the fluctuation amount (movement speed) is within a predetermined range (S05). In the moving speed of the welding torch 2, an appropriate speed (for example, 20 cm / min) is set, and a predetermined range is determined based on the appropriate speed in order to ensure welding quality. The predetermined range may be determined as, for example, within ± 5% of the appropriate speed of the welding torch 2. Data relating to the appropriate speed or the predetermined range is stored in the storage unit 13. The calculation unit 12 refers to the storage unit 13 and determines whether or not the moving speed of the welding torch 2 derived in S04 is within the predetermined range.

  If it is within the predetermined range (S05: YES), the calculation unit 12 performs a loop process to perform the process of S01 again.

  If not within the predetermined range (S05: NO), the calculation unit 12 outputs a predetermined signal to the notification unit 14 (S06). The notification unit 14 that has acquired the predetermined signal output from the calculation unit 12 utters a voice such as “the movement of the welding torch 2 is fast” from a speaker, for example, and arouses the welder. Or when the alerting | reporting part 14 contains a rotation lamp, you may blink a rotation lamp and arouse a welder.

  After performing the process of S06, the calculation unit 12 performs a loop process to perform the process of S01 again. When the torch switch 23 of the welding torch 2 is on, the calculation unit 12 may perform the processing from S01 to S06. Therefore, when the torch switch 23 of the welding torch 2 is turned off, the calculation unit 12 ends this process.

  The arc welding support apparatus 1 derives the moving speed of the welding torch 2 based on data related to a stationary object (stationary object data) in an image captured by the imaging unit 11. Therefore, even if it is difficult to detect the moving speed by an acceleration sensor or the like because the moving speed is low, the moving speed of the welding torch 2 can be derived with high accuracy.

  When a plurality of stationary objects are included in the stationary object data, the arc welding support apparatus 1 can accurately derive the moving speed of the welding torch 2 based on the stationary object having the shortest distance from the welding torch 2. .

  In the arc welding support device 1, the temporary fixing welded portion 32 provided on the welded portion 31 (welding line) of the base material 3 is set as a stationary object for deriving the moving speed of the welding torch 2. Therefore, the moving speed of the welding torch 2 can be derived with high accuracy by using the temporarily welded portion 32 that is a stationary object along the traveling direction of the welding torch 2.

  By storing data related to the shape or luminance amount of a general temporary fixing weld 32 in the storage unit 13 in advance, the temporary fixing weld 32 in the captured image is used as a marker for image analysis. The accuracy of deriving the distance from the stationary object such as the part 32 or the moving speed of the welding torch 2 can be improved.

(Embodiment 2)
FIG. 6 is a block diagram illustrating a configuration example of the arc welding support apparatus 1 (stereo camera) according to the second embodiment. FIG. 7 is a flowchart illustrating a processing procedure of the calculation unit 12 according to the second embodiment. FIG. 8 is an explanatory diagram relating to the brightness of the temporarily welded portion 32. FIG. 9 is an explanatory diagram relating to the derivation of the distance from the temporary fixing weld 32. The second embodiment is different from the first embodiment in processing related to a stationary object in a captured image, in which the imaging unit 11 is a stereo camera.

  The imaging unit 11 according to the second embodiment includes two lenses 111, and these lenses 111 are stereo cameras that are provided with a predetermined interval so that their viewing angles coincide with each other.

  Corresponding image sensors 112 are connected to the two lenses 111 as in the first embodiment. Each of these image sensors 112 is arranged in conformity with the focal length of the lens 111.

  Each of these image sensors 112 is connected to a corresponding AD conversion unit 113 as in the first embodiment, and each AD conversion unit 113 is connected to the arithmetic unit 12 and the like via the internal bus 15 so as to be communicable. ing.

  The process of the calculation part 12 is demonstrated based on the flowchart shown in FIG. The calculation unit 12 acquires the first image (S201). The computing unit 12 acquires a first image captured at the same timing by the two lenses 111 of the imaging unit 11. The image includes image data captured by the two lenses 111.

  The computing unit 12 extracts feature points of the first image (S202). The calculation unit 12 extracts feature points from the respective image data captured by the two lenses 111 acquired in S201. The feature point extraction is to extract a stationary object from these image data, and the calculation unit 12 extracts the feature point by, for example, pattern matching with the temporary welding portion 32 stored in the storage unit 13 in advance. In FIG. 8, the horizontal axis indicates the distance that is a vertical component with respect to the welding progress direction, and the vertical axis indicates the luminance amount. As shown in FIG. 8, the temporarily welded portion 32 tends to increase in luminance as it approaches the central portion, and can be extracted with high accuracy.

  The calculation unit 12 refers to data related to the shape or luminance amount of the temporary fixing weld 32 stored in advance in the storage unit 13 and performs edge detection processing on the acquired image data based on this data. Based on the result of the edge detection process, the calculation unit 12 extracts points constituting the edge, that is, points on the contour line, as feature points. The calculation unit 12 extracts the feature points of the image data by the one lens 111 and the corresponding feature points of the image data by the other lens 111 by performing the extraction of the feature points for each of the image data. Each feature point is stored in the storage unit 13.

  The computing unit 12 derives the distance between the welding torch 2 and the feature point (S203). The calculation unit 12 derives the distance from the feature point using, for example, a known triangulation. As shown in FIG. 9, the two lenses 111 are arranged side by side so that their viewing angles coincide with each other. Based on the distance (B) between the centers of the lenses 111, the distance (F) between the image sensor 112 and the lens 111, which is the focal length of the lens 111, and the parallax (S) based on the extracted feature points, the characteristics of the lens 111 and The distance (D) from the point is calculated (D = B × F / S). Since the imaging unit 11 including the lens 111 is provided in the welding torch 2, the distance (D) between the lens 111 and the feature point can be regarded as the distance between the welding torch 2 and the feature point.

  The calculation unit 12 performs the process of S204 in the same manner as the process S02 of the first embodiment. When the predetermined time has not elapsed (S204: NO), the calculation unit 12 performs the process of S204 again.

  When the predetermined time has elapsed (S204: YES), the calculation unit 12 acquires a second image (S205). The calculation unit 12 acquires the second image in the same manner as the process of S201. The second image is captured after a predetermined time has elapsed since the first image was captured.

  The computing unit 12 extracts feature points of the second image (S206). The calculation unit 12 extracts feature points of the second image as in the process of S202.

  The computing unit 12 derives the distance between the welding torch 2 and the feature point (S207). The calculation unit 12 derives the distance between the welding torch 2 and the feature point in the same manner as the process of S203.

  The computing unit 12 derives the fluctuation amount (movement speed) (S208). The computing unit 12 derives a difference (variation amount) between the distance from the feature point of the first image derived in S203 and the distance from the feature point of the second image derived in S207. The difference corresponds to the distance that the welding torch 2 has moved in the predetermined time in S204. When these feature points include a plurality of stationary objects, the calculation unit 12 may derive the amount of variation using the feature point of the stationary object having the shortest distance from the welding torch 2. By using the feature point of the stationary object having the shortest distance from the welding torch 2, the amount of variation can be derived with high accuracy. The computing unit 12 derives the moving speed of the welding torch 2 by dividing the derived variation (the distance traveled by the welding torch 2) by the predetermined time in S204.

  The calculation unit 12 performs the processes of S209 and S210 in the same manner as the processes S05 and S06 of the first embodiment.

  Since the imaging unit 11 of the arc welding support apparatus 1 is a stereo camera including two lenses 111, based on parallax or the like between image data captured by these lenses 111, a known triangulation can be used, for example. It is possible to efficiently derive the distance from a feature point that is a stationary object such as the stop weld 32. Since it is based on the distance to the derived feature point and the variation amount of the feature point, the moving speed of the welding torch 2 can be accurately derived even at a low speed that is difficult to detect with an acceleration sensor.

(Modification 1)
FIG. 10 is a block diagram illustrating a configuration example of the arc welding support apparatus 1 (a camera in a separate housing) according to the first modification. The third embodiment is different from the first embodiment in that the imaging unit 11 is provided separately from the welding torch 2.

The arc welding support device 1 of the first modification is provided in a separate device from the welding torch 2.
This separate apparatus is, for example, a welding power supply apparatus 4, and the arc welding support apparatus 1 is provided in the welding power supply apparatus 4. The arc welding support device 1 is provided so as to include a welded portion 31 (weld line) of the base material 3 and a welding torch 2 when a welder performs a welding operation at a viewing angle (viewing range) of the imaging unit 11. ing.

  The imaging unit 11 of the arc welding support device 1 is configured by a stereo camera including two lenses 111 as in the second embodiment. The calculation unit 12 acquires the first image in the same manner as the processing of the second embodiment, and acquires the second image after a predetermined time has elapsed.

  The calculation unit 12 extracts the torch body 21 of the welding torch 2 as a feature point extracted from the acquired first image and second image. The shape or luminance amount of the welding torch 2 is stored in advance in the storage unit 13, and the calculation unit 12 refers to the storage unit 13 from these images (image data captured by each of the lenses 111). 21 is extracted as a feature point.

  The calculation unit 12 derives a fluctuation amount based on each feature point extracted in the same manner as the processing of the second embodiment, and derives the moving speed of the welding torch 2 by dividing the fluctuation amount by a predetermined time. When the speed is not within the predetermined range, a predetermined signal is output so that notification is performed by the notification unit 14.

  Since the arc welding support device 1 is provided so that the welding torch 2 and the welded portion 31 (welding line) of the base material 3 are included in the field of view of the imaging unit 11, the welding torch is used between welding operations of the welder. 2 can always be imaged.

  By extracting the torch body 21 closest to the welded part 31 (weld line) as a feature point, the amount of variation can be derived with high accuracy.

  The arc welding support apparatus 1 can suppress the welding torch 2 from becoming heavy by being provided in the welding power source apparatus 4 or the like that is separate from the welding torch 2.

  Although the arc welding support apparatus 1 is provided in the welding power supply apparatus 4, it is not limited to this. The arc welding support device 1 may be provided in another device such as a consumable electrode wire feeding device that is separate from the welding torch 2 or in equipment installed at the welding site. Although the feature point to be extracted is the torch main body 21, it is not limited to this. Other parts such as the torch holder 22 of the welding torch 2 may be extracted as feature points.

(Modification 2)
In the present embodiment, the stationary object is identified based on the image captured by the imaging unit 11, and the moving speed of the torch is derived based on the amount of variation of the identified stationary object. However, the present invention is not limited to this. When starting welding, the imaging unit 11 is set so as to be in the center of the image obtained by imaging the welding line, and the calculation unit 12 derives a deviation amount between the welding line and the virtual center line in the image, and the deviation amount. Based on the above, the moving speed or moving amount of the torch may be derived.

  In the present embodiment, the temporary fixing weld portion 32 of welding is specified as a stationary object, and the moving speed of the torch is derived based on the amount of fluctuation of the specified stationary object. However, the present invention is not limited to this. Image data relating to the shape of the end portion of the weld line may be stored in the storage unit 13, and the calculation unit 12 may specify the end portion of the weld line as a stationary object and derive the moving speed of the torch.

  It should be thought that embodiment disclosed this time is an illustration and restrictive at no points. The scope of the present invention is defined by the terms of the claims, rather than the meanings described above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

DESCRIPTION OF SYMBOLS 1 Arc welding assistance apparatus 11 Image pick-up part 111 Lens 112 Image sensor 113 AD conversion part 12 Calculation part 13 Storage part 131 Recording medium 131P Program 14 Notification part 15 Internal bus 2 Welding torch 21 Torch main body 22 Torch holder 23 Torch switch 3 Base material 31 Covered object Welded part (welding line)
32 Temporary fixing weld (temporary fixing point)
4 Welding power supply

Claims (7)

An imaging unit provided in the welding torch so that the viewing angle includes the moving direction of the welding torch during arc welding operation;
A speed deriving unit for deriving a moving speed of the welding torch based on an image captured by the imaging unit;
An arc welding support apparatus comprising: a signal output unit that outputs a predetermined signal when the moving speed derived by the speed deriving unit is out of a predetermined speed range. The speed deriving unit includes:
An image acquisition unit for acquiring a first image and a second image captured after a predetermined time has elapsed since the first image was captured;
A stationary object identification unit that identifies a stationary object based on the acquired first image and second image,
The arc welding support apparatus according to claim 1, wherein the moving speed is derived based on a variation amount of the stationary object between the first image and the second image and the predetermined time. The imaging unit is a stereo camera,
The speed deriving unit includes a distance deriving unit for deriving a distance between the stationary object and the welding torch based on an image captured by the stereo camera.
The arc welding support apparatus according to claim 2, wherein a moving speed is derived based on a stationary object whose distance from the welding torch is within a predetermined distance among the plurality of identified stationary objects. The plurality of identified stationary objects include temporary welds or end points of weld lines,
The arc welding support apparatus according to claim 2 or 3, wherein the speed deriving unit derives a moving speed based on the temporary fixing welded portion or the end portion of the weld line. Deriving the moving speed of the welding torch based on the image taken by the imaging unit provided in the welding torch so that the viewing angle includes the moving direction of the welding torch during arc welding work,
An arc welding support method, comprising: outputting a predetermined signal when the derived moving speed is out of a predetermined speed range. The computer acquires an image captured by an imaging unit provided in the welding torch so that the viewing angle includes the moving direction of the welding torch during arc welding work,
Deriving the moving speed of the welding torch based on the acquired image,
A program for executing a process of outputting a predetermined signal when the derived moving speed is out of a predetermined speed range. An imaging unit provided to include a welding torch and a welded portion of a base material in a viewing angle;
A speed deriving unit for deriving a moving speed of the welding torch based on an image captured by the imaging unit;
An arc welding support apparatus comprising: a signal output unit that outputs a predetermined signal when the moving speed derived by the speed deriving unit is out of a predetermined speed range.

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