Aluminum Mig Welding Bath Visual Information Detection And Processing System

The quality of welded structure is fully dependent on the melting and solidifying process of weld pool after the material and structural parameters are determined. Therefore, controlling the melting state of weld pool is the key for the quality control of arc welding. This can be solved by the real-time feedback controlling both the pool melting state and the pool melting position in the welding process. Moreover the precondition of reaching this goal is the sensing melting state and pool melting position in real-tune. Recently, extensive and thorough research is carried out on control of carbon steel pulsed GTAW. However, research on aluminum pulsed GTAW were still little and the research on aluminum pulsed GMAW is nearly blank, because some factors such as thef surface of the aluminum can reflect the visible light in whole wave range and the contrast between the welding pool and the plate nearly is very weak lead. So it is difficult to take the image of weld pool of aluminum alloy by ordinary visual sensor.Aimed at inspect and process system for weld pool of aluminum pulsed GMAW, several aspects of the research is proposed in this paper. Firstly, clear image of weld pool is captured through visual sensing method. Secondly, shape parameters of weld pool are extracted by image processing, which is the base on modeling and controlling of welding process. Finally, primary research is carried out on seam tracking technology of welding process through active visual sensing method.Passive visual sensing method is the major method for sensing welding process, the principle of which is to capture weld pool image by the illumination of electric arc. In this paper, the application of passive visual sensing in pulsed GMAW is deeply analyzed. Through composite filter technology can solved interfered by electric arc and can achieved clear high contrast images of weld pool. For describing the shape of weld pool, this paper presented simple and valid shapeparameters for determining the shape of weld pool: the length lt, width Wt, and half-length ratioi Rhl of weld pool. At the same time, image processing calculus forextracting the shape parameters is designed and developed. And this calculus is composed by gray-scale processing, filter processing, edge enhancement processing, edge detect and extract processing. Compared with many methods of filter and edgedetectors, this paper finally adopts Wiener filter processing and Canny edge detector. Through practice proved this calculus has high precision.Through test proved that the system is designed can process image of weld pool, and can extract the max width and length of image of weld pool.