Tube Sheet Annular Seam Measurement Technology Based on Laser Collaboration With Vision Sensor

The fast and accurate locating of the tube-sheet annular seam is the key factors to ensure the high efficiency and quality of automatic welding of pressure vessels. Considering the problems of welding sheet deformation and tubes deviation caused by machining process and welding thermal, this paper builds an automatic welding robot platform, which is equipped with a measurement system coordinated by multiple lasers and visual sensors, and put forward a real-time welding distance measurement method based on cross lasers and visual sensors, at the same time, the multi spot laser assisted vision sensor is used to quickly and accurately measure the center of the tube, so as to guide the adjustment of the welding robot and posture of the welding torch in real time. Then, through the measurements of system error, static and dynamic measurement error, it is known that the dynamic accuracy of tube sheet welding distance is not less than 0.22mm, and the positioning accuracy of welded tube center is not less than 0.219mm, which can meet the accuracy requirements of automatic tube sheet welding.