Research On Visual Sensing Technology Of Structured-light Seam Detecting

Developing and applying new automatic and intelligent welding technology is the advanced demand of welding industry. And automatic seam tracking is the principal problem in automatic welding. Among various ways of sensing, structured-light visual sensing technology stands out for its information, sharp accuracy and adaptability.According to system characteristic and performance request, we design the system including the light filter system, the collectable diagram system, the handling diagram system and the regulating deviation system. Trigonometry measurement principle is studied and model is established. The models of coordinate transformation between workpiece and camera are presented. The models are very useful to the design of structure light sensor. The sensor designed based on the theory above is used in automatic welding.We use semiconductor laser instrument as illuminant and use CCD as photoelectric transformation element. Through the collecting card, which is a kind of image card directly get picture from CCD into display memory, the result can be obtained by image processing. Through adopting the smooth filter wave and other pretreatment for originality diagram of seam area, the interferential questions such as the splash and the arc light and so on were solved and we get to the seam area diagram which is clear and has no big noise.Preliminary seaming tracking experiments for V-groove seams are carried out with the help of the new designed structured-light visual sensing system. The results indicate that the coordinates of the feature points in images of the seams are obtained. The designed structured-light visual sensor system basically satisfies seam tracking and is well established for further improvement.