Study on the method of vision detection on penetration status in Laser-MIG hybrid welding

Penetration status is an important criterion to evaluate the weld quality of laser-MIG hybrid welding in gapped butt welding.In order to acquire the information of penetration status,vision sensors have been applied to detect the topside image of molten pool,image of keyhole and the backside image of molten pool in hybrid welding respectively.The results show that penetration status can't be identified by the methods of detecting the topside image of molten pool and image of keyhole with vision sensors in gapped butt hybrid welding.The backside image of molten pool recognizing the weld penetration status has been acquired by the vision detection method of applying an external illumination source and an appropriated filter.