Method and system for extracting geometric fixed point of underground roadway intersection

The invention provides an underground roadway intersection geometric fixed point extraction method and system. The underground roadway intersection geometric fixed point extraction method comprises the steps that S1, intersection three-dimensional point cloud to be processed is input, and a fitted ground plane equation and height information of a mine roadway are obtained; based on the ground plane equation and the height information of the mine laneway, segmenting the three-dimensional point cloud of the intersection to be processed into ground points and non-ground points, and extracting wall points with the most structural distinction degree and representativeness from the non-ground points; s2, projecting and transforming the wall surface points from the laser radar coordinate system to a ground plane coordinate system to obtain a wall surface point cloud after coordinate transformation; and S3, converting the wall point cloud after coordinate conversion into a two-dimensional occupied grid image, and ext