A study on anti-light disturbance in laser position detecting to welding seam

Abstract

Laser position detecting to weld seam is based on the principle of structured light measuring. The intense arc, combusting gas and spatters influence the acquisition of weld seam image in the process of welding. Therefore, the problem of anti-light disturbance is studied in four aspects. First, the forming factors of the light disturbance such as the arc and the melting cell radiation and so on is studied from the viewpoint of the distribution of spectrum energy. Matching the narrow-band filter with the wavelength of laser can obstruct the ultraviolet and infrared radiation. Secondly, the influence brought by the reflection on the surface of steel plate is studied and a neutral filter is used to absorb the light disturbance and then the signal-to-noise ratio of an image is improved. Thirdly, there are still some stripes of spatters on image after compound filtering. For calculating the position of weld seam, the technology of digital image processing is also adopted. And finally, obstructing the light disturbance by a mechanical part is also an important measure. A baffle installed between the welding torch and the laser sensor can effectively obstruct some of the spatters. After taking the above four aspects measures, the light disturbance is better eliminated and a clear image is acquired. It can be used to track the weld seam by crawling arc welding robot.