Image taking and processing of molten pool characters during aluminum alloy TIG welding

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