公开(公告)号：US11836896B2

公开(公告)日：2023-12-05

申请号：US18320280

申请日：2023-05-19

申请人： Nanjing University of Aeronautics and Astronautics

发明人： Jun Wang ,  Kun Xiao ,  Zikuan Li ,  Tianchi Zhong

IPC分类号： G06T3/60 ,  G06T3/40

CPC分类号： G06T3/60 ,  G06T3/4038

摘要： A semantic segmentation method for aircraft point cloud based on voxelization and three views, including: filtering a collected point cloud followed by centralization to obtain a centralized point cloud; inputting the centralized point cloud into a T-Net rotation matrix network; rotating the centralized point cloud to a front side followed by voxelization to obtain a voxelized point cloud; subjecting the voxelized point cloud to voxel filling to obtain a voxel-filled point cloud; calculating thickness maps of three views of the voxel-filled point cloud, followed by sequentially stitching and inputting to the point cloud semantic segmentation network to train the point cloud semantic segmentation network; inputting the collected point cloud into the trained point cloud semantic segmentation network; and predicting a result semantic segmentation of a 3D point cloud of the aircraft.

公开(公告)号：US11830164B2

公开(公告)日：2023-11-28

申请号：US18316317

申请日：2023-05-12

申请人： Nanjing University of Aeronautics and Astronautics

发明人： Jun Wang ,  Zhongde Shan ,  Kaijun Zhang ,  Zikuan Li ,  Chao Li

IPC分类号： G06T3/40

CPC分类号： G06T3/4046

摘要： This application discloses a semantic learning-based down-sampling method of point cloud data of an aircraft, including: (S1) constructing a multi-input encoder based on feature learning according to point cloud semantic learning principle; inputting the point cloud data of the aircraft and feature point data into the multi-input encoder for feature fusion followed by decoding using a decoder the multi-input feature fused data to obtain to-be-measured data; (S2) constructing and training a point cloud feature weight calculation network based on semantic learning to acquire a feature weight of each point in the to-be-measured data; and (S3) performing spatial weighted sampling on the feature weight of each point in the to-be-measured data followed by down-sampling based on Gaussian distribution-based spatial sampling principle.

公开(公告)号：US11661686B2

公开(公告)日：2023-05-30

申请号：US17702145

申请日：2022-03-23

申请人： NANJING UNIVERSITY OF AERONAUTICS AND ASTRONAUTICS

发明人： Zhongde Shan ,  Jun Wang ,  Yaoyao Wang ,  Haoqin Yang ,  Chao Li

IPC分类号： D04C3/48 ,  D04C3/40

CPC分类号： D04C3/48 ,  D04C3/40

摘要： A mechanism for radially inserting a yarn into a 3D braided preform, including a first bracket, an upper linear actuator, a support mechanism, an upper yarn insertion device, a yarn carrying device, an upper gear ring, a lower yarn insertion device, a lower linear actuator, a second bracket, a lower gear ring, a lower gear, a lower motor, a lower circular track, an upper circular track, a base, an upper gear, a pneumatic transmission and control device and an upper motor.

公开(公告)号：US11557029B2

公开(公告)日：2023-01-17

申请号：US17574827

申请日：2022-01-13

申请人： Nanjing University of Aeronautics and Astronautics

发明人： Zhongde Shan ,  Jun Wang ,  Anyi Huang ,  Qian Xie

IPC分类号： G06T7/00 ,  G06T7/50 ,  G06T7/11 ,  G06V10/77 ,  G06V10/774 ,  G06V20/70 ,  G06T7/30 ,  G06V10/776 ,  G06V10/25 ,  G06V10/26

摘要： A method for detecting and recognizing surface defects of an automated fiber placement composite based on an image converted from point clouds, including: acquiring a surface point cloud of the automated fiber placement composite; fitting a plane to surface point data; calculating a distance from each point of the surface point cloud to a fitted plane; enveloping the surface point cloud by OBB, and generating a grayscale image according to the OBB and the distance; constructing a pre-trained semantic segmentation network for defect of fiber placement, and inputting the grayscale image to segment and recognize defect areas thereon; mapping a segmentation result output by the semantic segmentation network to the point cloud followed by defect evaluation and visualization.

公开(公告)号：US11543795B2

公开(公告)日：2023-01-03

申请号：US17026262

申请日：2020-09-20

申请人： NANJING UNIVERSITY OF AERONAUTICS AND ASTRONAUTICS

发明人： Jun Wang ,  Zeyong Wei ,  Honghua Chen

IPC分类号： G05B19/402 ,  G01M5/00

摘要： The present invention relates to an airplane structure stiffener repair method based on measured data guidance. The method includes: respectively measuring point cloud data on a surface of a structure stiffener and point cloud data on a surface of a to-be-assembled position of a body; respectively extracting all assembly plane features in two point cloud data based on an RANSAC algorithm; performing pre-alignment according to the plane features; performing accurate alignment based on a signed distance constraint according to repair tolerance requirements; and calculating a repair allowance, and generating a machining path to serve as an accurate machining basis. According to the method in the present invention, a repair amount can be accurately calculated by virtue of an alignment algorithm of the signed distance constraint, and an envelope relationship during model matching is met.

公开(公告)号：US11532123B2

公开(公告)日：2022-12-20

申请号：US17574796

申请日：2022-01-13

申请人： Nanjing University of Aeronautics and Astronautics

发明人： Jun Wang ,  Zikuan Li ,  Anyi Huang ,  Qian Xie

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.

公开(公告)号：US11037346B1

公开(公告)日：2021-06-15

申请号：US17026260

申请日：2020-09-20

申请人： NANJING UNIVERSITY OF AERONAUTICS AND ASTRONAUTICS

发明人： Jun Wang ,  Yan Wang ,  Yuanpeng Liu ,  Qian Xie

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.