WELDING MONITORING APPARATUS AND WELDING MONITORING METHOD
Provided is a welding monitoring apparatus that monitors a welding state of a V-convergence region in which a strip-shaped metal sheet is converged in a V-shape, when the metal sheet is cylindrically formed while being conveyed, and both side edges of the metal sheet are heated and melted in a manner of being butted each other while being converged in the V-shape, such that an electric resistance welded steel pipe is manufactured. This welding monitoring apparatus includes an image capturing unit that captures images of a region including the V-convergence region in time series; and an image processing unit that extracts a welding point based on the images captured in time series and detects the presence or absence and a position of irregular arcing at the welding point or on an upstream side of the welding point.
1 . A welding monitoring apparatus that monitors a welding state of a V-convergence region in which a strip-shaped metal sheet is converged in a V-shape, when the metal sheet is cylindrically formed while being conveyed, and both side edges of the metal sheet are heated and melted in a manner of being butted each other while being converged in the V-shape, such that an electric resistance welded steel pipe is manufactured, the apparatus comprising:
an image capturing unit that captures images of a region including the V-convergence region in time series; and
an image processing unit that extracts a welding point based on the images captured in time series and detects the presence or absence and a position of irregular arcing at the welding point or on an upstream side of the welding point.
2 . The welding monitoring apparatus according to claim 1 ,
wherein the images captured by the image capturing unit are RGB images, and
wherein the image processing unit
extracts at least one of a red image and a blue image from the RGB images,
performs inverted binarization and labeling of the red image with respect to the red image, and
detects a high-luminance portion in the blue image with respect to the blue image.
3 . The welding monitoring apparatus according to claim 1 ,
wherein the image capturing unit is a camera capturing 200 frames or more per second.
4 . A welding monitoring method for monitoring a welding state of a V-convergence region in which a strip-shaped metal sheet is converged in a V-shape, when the metal sheet is cylindrically formed while being conveyed, and both side edges of the metal sheet are heated and melted in a manner of being butted each other while being converged in the V-shape, such that an electric resistance welded steel pipe is manufactured, the method comprising:
an image capturing step of capturing images of a region including the V-convergence region in time series; and
a detecting step of extracting a welding point based on the images captured in time series and detecting the presence or absence and a position of irregular arcing at the welding point or on an upstream side of the welding point.
5 . The welding monitoring method according to claim 4 ,
wherein RGB images are used as the images, and
wherein in the detecting step,
at least one of a red image and a blue image is extracted from the RGB images,
inverted binarization and labeling of the red image are performed with respect to the red image, and
a high-luminance portion in the blue image is detected with respect to the blue image.
6 . The welding monitoring method according to claim 4 ,
wherein in the image capturing step, images are captured at a frame rate of 200 frames or more per second.
7 . The welding monitoring method according to claim 4 , further comprising:
a marking step of marking the position of the irregular arcing in a longitudinal direction in the electric resistance welded steel pipe.
8 . The welding monitoring method according to claim 7 , further comprising:
a defect presence-or-absence specifying step of performing an ultrasonic test with respect to a region to which the marking is applied.
9 . The welding monitoring method according to claim 4 , further comprising:
a tracking step of tracking the position of the irregular arcing in a longitudinal direction in the electric resistance welded steel pipe.
10 . The welding monitoring apparatus according to claim 2 ,
wherein the image capturing unit is a camera capturing 200 frames or more per second.
11 . The welding monitoring method according to claim 5 ,
wherein in the image capturing step, images are captured at a frame rate of 200 frames or more per second.
12 . The welding monitoring method according to claim 5 , further comprising:
a marking step of marking the position of the irregular arcing in a longitudinal direction in the electric resistance welded steel pipe.
13 . The welding monitoring method according to claim 6 , further comprising:
a marking step of marking the position of the irregular arcing in a longitudinal direction in the electric resistance welded steel pipe.
14 . The welding monitoring method according to claim 5 , further comprising:
a tracking step of tracking the position of the irregular arcing in a longitudinal direction in the electric resistance welded steel pipe.
15 . The welding monitoring method according to claim 6 , further comprising:
a tracking step of tracking the position of the irregular arcing in a longitudinal direction in the electric resistance welded steel pipe.
16 . The welding monitoring method according to claim 11 , further comprising:
a marking step of marking the position of the irregular arcing in a longitudinal direction in the electric resistance welded steel pipe.
17 . The welding monitoring method according to claim 16 , further comprising:
a defect presence-or-absence specifying step of performing an ultrasonic test with respect to a region to which the marking is applied.
18 . The welding monitoring method according to claim 11 , further comprising:
a tracking step of tracking the position of the irregular arcing in a longitudinal direction in the electric resistance welded steel pipe.
19 . The welding monitoring method according to claim 12 , further comprising:
a defect presence-or-absence specifying step of performing an ultrasonic test with respect to a region to which the marking is applied.
20 . The welding monitoring method according to claim 13 , further comprising:
a defect presence-or-absence specifying step of performing an ultrasonic test with respect to a region to which the marking is applied.