A visual measurement method is proposed

which is the three-dimensional contour of the groove and weld surface based on the grid structure light. A visual measurement system is built with cameras

lasers

and adjustment mechanisms as core. The grid stripe visual images are collected from the weld profiles of submerged arc plate surfacing and groove butt joint. And the correlative relationship between the contour geometry change and the grid stripe distortion characteristic is analyzed. The coordinates of the grid nodes are extracted by using algorithms

such as window opening

threshold segmentation

refinement and grid cross. Three methods of surface reconstruction are tried based on the node point cloud data. The actual verification results show that it is feasible to obtain the digital contour of the weld surface based on the coordinates of the visual measurement grid nodes.