Method for automatic glue-spraying of stringer and inspection of glue-spraying quality

    公开(公告)号:US11504731B2

    公开(公告)日:2022-11-22

    申请号:US17169538

    申请日:2021-02-07

    摘要: A method for automatic glue-spraying of stringers and inspection of glue-spraying quality based on measured data. Three-dimensional (3D) point cloud data of a stringer-skin assembly is collected by 3D laser scanner, and then processed by denoising and sampling. Feature points of an intersection line of a site to be glued of the stringer-skin assembly are extracted by K-means clustering method based on Gaussian mapping, and a minimum spanning tree is constructed based on a set of the extracted feature points. A connected region is established to obtain an initial feature intersection line of the string-skin assembly, which is optimized by random sample consensus algorithm to remove redundant small branch structures to obtain the actual glue-spraying trajectory. The quality of the glue sprayed on the stringer-skin assembly is inspected by line laser to determine positions of the defects, which are then subjected to secondary glue-spraying.

    Method for visualizing large-scale point cloud based on normal

    公开(公告)号:US11532123B2

    公开(公告)日:2022-12-20

    申请号:US17574796

    申请日:2022-01-13

    IPC分类号: G06T17/00

    摘要: A method for visualizing a large-scale point cloud based on normal, including: (S1) according to a spatial structure of a point cloud data, constructing a balanced octree structure of a node point cloud; (S2) according to the balanced octree structure and normal information of a point cloud, constructing an octree structure with the normal information; and constructing a normal level-of-detail (LOD) visualization node through downsampling; and (S3) determining a node scheduling strategy according to a relationship between a viewpoint, a viewing frustum and a normal of a render node; and respectively calling a reading thread and a rendering thread to simultaneously perform reading and rendering according to the node scheduling strategy.

    Multi-station scanning global point cloud registration method based on graph optimization

    公开(公告)号:US11037346B1

    公开(公告)日:2021-06-15

    申请号:US17026260

    申请日:2020-09-20

    IPC分类号: G06T11/20 G06T7/70

    摘要: Disclosed a multi-station scanning global point cloud registration method based on graph optimization, including acquiring multi-station original three-dimensional point cloud data; based on initial registration of targets, completing initial registration of point cloud data at adjacent stations by virtue of the target at each angle of view; calculating a point cloud overlap area at adjacent angles of view, and calculating areas of overlap regions of adjacent point cloud by a gridded sampling method; constructing a fine registration graph structure, and constructing a fine registration graph by taking point cloud data of each station as a node of the graph and taking an overlap area of the point cloud data of adjacent stations as a side of adjacent nodes of the graph structure; and based on loop closure fine registration based on graph optimization, gradually completing point cloud fine registration of the whole aircraft according to a specific closure sequence.

    Method for automated flushness measurement of point cloud rivets

    公开(公告)号:US11538181B2

    公开(公告)日:2022-12-27

    申请号:US17026206

    申请日:2020-09-19

    摘要: A method for automated flushness measurement of point cloud rivets, including: extracting a rivet outline by adopting an RANSAC circle fitting algorithm, and determining a center, a radius and a normal vector of an outline circle; extracting point cloud of a rivet head for a single rivet outline; extracting point cloud around the rivet for the single rivet outline; and generating a distance color difference map reflecting rivet flushness according to the point cloud of the rivet head and the point cloud around the rivet. According to the present invention, the point cloud of the rivet head and the point cloud around the rivet can be respectively extracted, and the distance color difference map reflecting the rivet flushness is generated according to the point cloud of the rivet head and the point cloud around the rivet, so that the rivet flushness is rapidly and effectively measured.

    Method for measuring a seam on aircraft skin based on large-scale point cloud

    公开(公告)号:US11532121B2

    公开(公告)日:2022-12-20

    申请号:US17169527

    申请日:2021-02-07

    IPC分类号: G06K9/00 G06T17/00 G06V20/00

    摘要: A method for measuring a seam on aircraft skin based on a large-scale point cloud is disclosed. A point cloud density of each point in an aircraft skin point cloud is calculated. Seam and non-seam point clouds are divided according to a discrepancy of the calculated point cloud density. A point is selected from the point cloud of the seam area, and a section at the point is extracted. A certain range of the seam and non-seam point clouds is projected to the section and a projected point cloud is acquired. A calculation model of flush and gap is constructed, and the flush and the gap of the aircraft skin seam at the measuring point is calculated according to the projected point cloud and the calculation model.

    Code point-driven three-dimensional point cloud deformation method

    公开(公告)号:US11308632B2

    公开(公告)日:2022-04-19

    申请号:US17169513

    申请日:2021-02-07

    摘要: Disclosed herein is a code point-driven three-dimensional (3D) point cloud deformation method. In the method, movable code points and fixed code points are respectively pasted on a moving structure and a static structure. Reference poses of the movable code points and fixed code points are obtained by a dual-camera measurement system, and a 3D point cloud reference model containing the moving structure and the static structure is obtained by 3D laser scanning. A transformation matrix of each code point is calculated, and a real-time point cloud model is established based on the transformation matrix to complete the real-time and dynamic measurement of the moving structure.