Laser Vision Detection Method for the Thermal Deformation of Tubesheet Welding

The thermal deformation of tubesheet in the welding process was inevitable. This can lead to the welding distance between tungsten electrode and tubesheet varied. The undercut, breakage and uneven weld of the tubes can be caused by the unreasonable welding distance. This paper developed a laser vision detection method to project lasers on tubesheet plane and extracted the intersection coordinate of cross-lines laser. The mathematical model between intersection coordinate and tubesheet thermal deformation was established. The steady and accuracy of this method in the detection of tubesheet thermal deformation were verified. The static detection error was no more than 0.006 mm. The maximum thermal deformation of tubesheet in our experiment was no more than - 2.6 mm. This study laid a foundation for on-line detect thermal deformation of robot welding tubesheet.