Welding position detecting apparatus and welding position detecting method for laser beam welding

Patent metadata

Field	Value
Publication number	US-9492888-B2
Application number	US-201214364146-A
Country	US
Kind code	B2
Filing date	Dec 7, 2012
Priority date	Dec 15, 2011
Publication date	Nov 15, 2016
Grant date	Nov 15, 2016

Abstract

A welding position detecting apparatus for laser beam welding includes: an imaging device that captures, at a predetermined time interval, images of an irradiated portion of a welding material irradiated with a welding laser beam, and a surrounding area thereof, of a welding material; an image processing device that identifies a position of the irradiated portion irradiated with the welding laser beam by performing image processing calculating, from two or more images acquired by the imaging device, a direction and an amount of parallel movement of points in the images; and a display device that displays the position of the irradiated portion irradiated with the welding laser beam, the position being identified by the image processing device.

First claim

The invention claimed is:

1. A welding position detecting apparatus for laser beam welding, the welding position detecting apparatus comprising:
an imaging device that captures, at a predetermined time interval, images of an irradiated portion of a welding material irradiated with a welding laser beam, and a surrounding area thereof, of a welding material;
an image processing device that identifies a position of the irradiated portion irradiated with the welding laser beam by performing image processing calculating, from two or more images acquired by the imaging device, a direction and an amount of parallel movement of points in the images; and
a display device that displays the position of the irradiated portion irradiated with the welding laser beam, the position being identified by the image processing device.

2. The welding position detecting apparatus for laser beam welding according to claim 1 , further comprising:
a single-wavelength optical source that irradiates the irradiated portion, and the surrounding area thereof, of the welding material with light having a single wavelength ranging from 800 nm to 900 nm; and
a band-pass filter disposed between the imaging device and the irradiated portion, the band-pass filter having a transmission property of transmitting light having the wavelength of the single-wavelength optical source.

3. The welding position detecting apparatus for laser beam welding according to claim 2 , wherein
the image processing device comprises:
a motion vector distribution calculating unit that calculates, from two or more images acquired by the imaging device, a distribution of the direction and the amount of parallel movement of points in the images;
a travel direction component calculating unit that calculates, from the distribution of the direction and the amount of parallel movement of the points, a travel direction component of the welding material;
an overall mean calculating unit that calculates a travel speed component of the welding material by calculating a mean of the distribution of the direction and the amount of parallel movement of the points relative to an entire image of the travel direction component of the welding material;
a difference calculating unit that acquires a mean deviation by calculating a difference between the distribution of the direction and the amount of parallel movement of the points and the travel speed component of the welding material; and
an irradiated portion identifying unit that identifies, from the mean deviation, the position of the irradiated portion irradiated with the welding laser beam.

4. The welding position detecting apparatus for laser beam welding according to claim 1 , wherein
the image processing device comprises:
a motion vector distribution calculating unit that calculates, from two or more images acquired by the imaging device, a distribution of the direction and the amount of parallel movement of points in the images;
a travel direction component calculating unit that calculates, from the distribution of the direction and the amount of parallel movement of the points, a travel direction component of the welding material;
an overall mean calculating unit that calculates a travel speed component of the welding material by calculating a mean of the distribution of the direction and the amount of parallel movement of the points relative to an entire image of the travel direction component of the welding material;
a difference calculating unit that acquires a mean deviation by calculating a difference between the distribution of the direction and the amount of parallel movement of the points and the travel speed component of the welding material; and
an irradiated portion identifying unit that identifies, from the mean deviation, the position of the irradiated portion irradiated with the welding laser beam.

5. A welding position detecting method for laser beam welding, the welding position detecting method comprising:
imaging, at a predetermined time interval, an irradiated portion irradiated with a welding laser beam, and a surrounding area thereof, of a welding material;
identifying a position of the irradiated portion irradiated with the welding laser beam by performing image processing calculating, from two or more images acquired at the imaging, a direction and an amount of parallel movement of points in the images; and
displaying the position of the irradiated portion irradiated with the welding laser beam, the position being identified at the identifying.

Assignees

• Kodama Toshifumi
• Yano Koji
• Suzuki Masahito
• Jfe Steel Corp

Inventors

• Kodama Toshifumi
• Yano Koji
• Suzuki Masahito

Classifications

• G06T2207/30152

  Solder · CPC title

• B23K2103/04

  Steel {or steel} alloys · CPC title

• G06T2207/30136

  Metal · CPC title

• G01B11/002

  for measuring two or more coordinates · CPC title

• G06T2207/10048

  Infrared image · CPC title