Weld groove forming method and hollow article

A weld groove forming method comprising:

• (S110) determining whether a side end of a pipe is configured to be processed into a form of a true circle by using a sensor robot;
• and
• (S220) forming a weld groove in a form of the true circle at the side end of the pipe by using an automatic beveling machine when the sensor robot determines that the side end of the pipe is configured to be processed into a form of the true circle in the step (S110),
• wherein the sensor robot is configured to (1) scan a side end of the hollow article in 2D or 3D, (2) store the scanned image of the hollow article as a measured image, (3) form a virtual image in a form of an annular ring, (4) overlap the virtual image with the measured image and determine whether the thickness portion of the virtual image is completely included in the thickness portion of the measured image, and also the thickness of the virtual image is in a range of 87.5% to 95% of an average thickness of the measured image, (5) determine that the side end of the hollow article is configured to be processed into a form of a true circle when the thickness portion of the virtual image is completely included in the thickness portion of the measured image, and also the thickness of the virtual image is in the range of 87.5% to 95% of the average thickness of the measured image, (6) determine the side end of the hollow article is not configured to be processed into a form of a true circle when the thickness portion of the virtual image is not completely included in the thickness portion of the measured image, or the thickness of the virtual image is in the range of 87.5% to 95% of the average thickness of the measured image, (7) transmit a beveling initiation signal to an automatic beveling machine, and (8) continuously measure the distance between the beveling blade of the automatic beveling machine and a to-be-beveled part of the hollow article and continuously transmit the measured value to the automatic beveling machine,
• wherein the step (S110) comprises:
• (S110-1) scanning the side end of the pipe to obtain a measured image in a form of an annular ring by using the sensor robot;
• (S110-2) overlapping the measured image with a predetermined virtual image in a form of an annular ring and also in a form of the true circle and determining whether the thickness portion of the virtual image is completely included in the thickness portion of the measured image, and also the thickness of the virtual image is in the range of 87.5% to 95% of the average thickness of the measured image by using the sensor robot;
• and
• (S110-3) determining that the side end of the pipe is configured to be processed into a form of the true circle by using the sensor robot, when the thickness portion of the virtual image is completely included in the thickness portion of the measured image, and also the thickness of the virtual image is in the range of 87.5% to 95% of the average thickness of the measured image in the step (S110-2).