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公开(公告)号:US20220182593A1
公开(公告)日:2022-06-09
申请号:US17680390
申请日:2022-02-25
Inventor: Chun YIN , Yuhua CHENG , Zeqi WANG , Xutong TAN , Kai CHEN , Gen QIU , Jianhao LUO , Junjie LIU , Zhibo LI , Aolin YANG
IPC: H04N13/15 , H04N13/239 , H04N13/254 , H04N13/246 , G06T7/33
Abstract: A method for high-precision true color three dimensional reconstruction of mechanical component. Firstly performs image acquisition: the left and right high-resolution grayscale cameras are fixed at same height and spaced at certain distance, an optical transmitter fixed between the two grayscale cameras, and low-resolution color camera fixed above optical transmitter, thus images of measured high-precision mechanical component are shot. Then performs image processing: all images are transmitted to a computer, which uses image processing to record surface information of measured high-precision mechanical component in the point cloud by high-precision true color three-dimensional reconstruction, which reflects color texture information of the surface, so as to realize the non-contact high-precision true color three dimensional reconstruction of high-precision mechanical component. The method uses binocular high-precision grayscale cameras instead of binocular color cameras, which broadens the range of capture wavelengths, retains richer texture details of high-precision mechanical component and improves accuracy of measurement.
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公开(公告)号:US20210383563A1
公开(公告)日:2021-12-09
申请号:US17401760
申请日:2021-08-13
Inventor: Yuhua CHENG , Chun YIN , Xiao YANG , Kai CHEN , Xuegang HUANG , Gen QIU , Yinze WANG
Abstract: The present invention provides a method for quantitatively identifying the defects of large-size composite material based on infrared image sequence, firstly obtaining the overlap area of an infrared splicing image, and dividing the infrared splicing image into three parts according to overlap area: overlap area, reference image area and registration image area, then extracting the defect areas from the infrared splicing image to obtain P defect areas, then obtaining the conversion coordinates of pixels of defect areas according to the three parts of the infrared splicing image, and further obtaining the transient thermal response curves of centroid coordinate and edge point coordinates, finding out the thermal diffusion points from the edge points of defect areas according to a created weight sequence and dynamic distance threshold εttr×dp_max, finally, based on the thermal diffusion points, the accurate identification of quantitative size of defects are completed.
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公开(公告)号:US20230339112A1
公开(公告)日:2023-10-26
申请号:US18140784
申请日:2023-04-28
Inventor: Chun YIN , Yan GAO , Zhongbao YAN , Kai CHEN , Yuhua CHENG , Xutong TAN , Junyang LIU
CPC classification number: B25J9/1664 , B25J9/1671 , B25J9/1692 , B25J19/021
Abstract: Robot assisted multi-view 3D scanning measurement based on path planning includes firstly, establishing a virtual simulation platform to complete the setting of measurement poses and measurement paths and perform the path evaluations of measurement paths. Then, completing the preliminary hand-eye calibration based on the properties of Kronecker product, and the preliminary hand-eye calibration is optimized by establishing a reprojection error cost function as the fitness function of the particle swarm optimization algorithm. Lastly, moving the robot to the measurement poses of the planned measurement paths, obtaining a single-view point cloud of the measured object and transforming it from the camera coordinate system to the robot base coordinate system to obtain a registered single-view point cloud based on the optimized hand-eye matrix. When registered single-view point clouds of all measurement poses are obtained, the points under the robot base coordinate system form a complete point cloud of the measured object.
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公开(公告)号:US20190228517A1
公开(公告)日:2019-07-25
申请号:US16370136
申请日:2019-03-29
Inventor: Yuhua CHENG , Chun YIN , Haonan ZHANG , Xuegang HUANG , Ting XUE , Kai CHEN , Yi LI
Abstract: The present invention provides a method for separating out a defect image from a thermogram sequence based on feature extraction and multi-objective optimization, we find that different kinds of TTRs have big differences in some physical quantities, such as the energy, temperature change rate during endothermic process, temperature change rate during endothermic process, average temperature, maximum temperature. The present invention extract these features (physical quantities) and cluster the selected TTRs into L clusters based on their feature vectors, which deeply digs the physical meanings contained in each TTR, makes the clustering more rational, and improves the accuracy of defect separation. Meanwhile, the present invention creates a multi-objective function to select a RTTR for each cluster based on multi-objective optimization. The multi-objective function does not only fully consider the similarities between the RTTR and other TTRs in the same cluster, but also considers the dissimilarities between the RTTR and the TTRs in other clusters, the RTTR is more representative, which guarantees the accuracy of describing the defect outline.
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公开(公告)号:US20190228221A1
公开(公告)日:2019-07-25
申请号:US16370202
申请日:2019-03-29
Inventor: Chun YIN , Yuhua CHENG , Ting XUE , Xuegang HUANG , Haonan ZHANG , Kai CHEN , Anhua SHI
Abstract: A method for separating out a defect image from a thermogram sequence based on weighted naive Bayesian classifier and dynamic multi-objective optimization. A method extracts these features and classifies the selected TTRs into K categories based on their feature vectors through a weighted naive Bayesian classifier, which deeply digs the physical meanings contained in each TTR, makes the classification of TTRs more rational, and improves the accuracy of defect image's separation. Meanwhile, the multi-objective function does not only fully consider the similarities between the RTTR and other TTRs in the same category, but also considers the dissimilarities between the RTTR and the TTRs in other categories, thus the RTTR selected is more representative, which guarantees the accuracy of describing the defect outline. The initial TTR population approximate solution for multi-objective optimization is chosen according to the previous TTR populations, which makes the multi-objective optimization dynamic and reduces its time consumption.
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公开(公告)号:US20180335403A1
公开(公告)日:2018-11-22
申请号:US15681186
申请日:2017-08-18
Inventor: Yuhua CHENG , Libing BAI , Yonggang WANG , Jie ZHANG , Chun YIN , Shuai SHI , Xue CHEN
IPC: G01N27/82
Abstract: The present invention provides a method for simulating magnetic flux leakage based on loop current, the magnetic distribution of a single loop current is obtained by solid angle, then the magnetic field distribution of a semi-infinite solenoid is obtained based on the assumption of arrangement of loop currents in the magnetized specimen, and its equation is given; and the JA hysteresis model is introduced to obtain the distribution of quasi-static magnetic flux leakage field, on the basis of analyzing the relation between the distribution of a loop current on the surface of the defect and the excitation magnetic field, the distribution of quasi-static magnetic flux leakage field is obtained based on the semi-infinite solenoid.
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