Abstract: Image sensing system of the molten pool during aluminum alloy’s TIG welding is established, and conditions of obtaining the image of the molten pool of aluminum alloy are investigated. The matching relations between the image sensing system and the characteristic of welding power supply is discussed. The special position relations of the each part of image sensing system are described. A lot of front and back images of the molten pool are obtained from different welding parameters. In order to acquire image of molten pool, the aluminum alloy’s characteristic of the molten pool is analyzed, and the correlation median filter is designed. Exacting edge of the molten pool image, which is the basement for intelligent control of the alu-minum alloy’s TIG welding, is obtained by double thresholding based on the statistics and wavelet transform.

Key words: Aluminum alloy, Image processing, Power characteristic matching, TIG welding, Vision sensing system