TUNNEL POINT CLOUD FILTERING METHOD BASED ON ELLIPTIC CYLINDRICAL MODEL

The large number of bolts and screws that attached to the subway shield ring plates, along with the great amount of accessories of metal stents and electrical equipments mounted on the tunnel walls, make the laser point cloud data include lots of non-tunnel section points (hereinafter referred to as non-points), therefore affecting the accuracy for modeling and deformation monitoring. This paper proposed a filtering method for the point cloud based on the elliptic cylindrical model. The original laser point cloud data was firstly projected onto a horizontal plane, and a searching algorithm was given to extract the edging points of both sides, which were used further to fit the tunnel central axis. Along the axis the point cloud was segmented regionally, and then fitted as smooth elliptic cylindrical surface by means of iteration. This processing enabled the automatic filtering of those inner wall non-points. Experiments of two groups showed coincident results, that the elliptic cylindrical model based method could effectively filter out the non-points, and meet the accuracy requirements for subway deformation monitoring. The method provides a new mode for the periodic monitoring of tunnel sections all-around deformation in subways routine operation and maintenance.

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The Application and Research of Terrestrial 3D Laser Scanning Technology in Tunnel Survey

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.709.465 ◽

2014 ◽

Vol 709 ◽

pp. 465-468

Author(s):

Xian Quan Han ◽

Fei Qin ◽

Zhen Zhang ◽

Shang Yi Yang

Keyword(s):

Point Cloud ◽

Laser Scanning ◽

3D Model ◽

Analysis Procedure ◽

Surface Model ◽

Point Cloud Data ◽

3D Laser Scanning ◽

Cloud Data ◽

Experimental Application ◽

Tunnel Section

This paper examines the basic flow and processing of the terrestrial 3D Laser scanning technology in the tunnel survey. The use of the method is discussed, point cloud data which have been registered, cropped can be constructed to a complete tunnel surface model. An example is given to extract the tunnel section and calculate the excavation of the tunnel. Result of the experimental application of this analysis procedure is given to illustrate the proposed technique can be flexibly used according to the need based on its 3D model. The feasibility and advantages of terrestrial 3D laser scanning technology in tunnel survey is also considered.

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A posture measurement approach for an articulated manipulator by RGB-D cameras

International Journal of Advanced Robotic Systems ◽

10.1177/1729881419838130 ◽

2019 ◽

Vol 16 (2) ◽

pp. 172988141983813

Author(s):

Haobin Shi ◽

Meng Xu ◽

Kao-Shing Hwang ◽

Chia-Hung Hung

Keyword(s):

Point Cloud ◽

Original Method ◽

Consensus Method ◽

Average Error ◽

Normal Vector ◽

Point Cloud Data ◽

Sample Standard Deviation ◽

Cylindrical Model ◽

Cloud Data ◽

Posture Measurement

The objective of this article aims at the safety problems where robots and operators are highly coupled in a working space. A method to model an articulated robot manipulator by cylindrical geometries based on partial cloud points is proposed in this article. Firstly, images with point cloud data containing the posture of a robot with five resolution links are captured by a pair of RGB-D cameras. Secondly, the process of point cloud clustering and Gaussian noise filtering is applied to the images to separate the point cloud data of three links from the combined images. Thirdly, an ideal cylindrical model fits the processed point cloud data are segmented by the random sample consensus method such that three joint angles corresponding to three major links are computed. The original method for calculating the normal vector of point cloud data is the cylindrical model segmentation method, but the accuracy of posture measurement is low when the point cloud data is incomplete. To solve this problem, a principal axis compensation method is proposed, which is not affected by number of point cloud cluster data. The original method and the proposed method are used to estimate the three joint angular of the manipulator system in experiments. Experimental results show that the average error is reduced by 27.97%, and the sample standard deviation of the error is reduced by 54.21% compared with the original method for posture measurement. The proposed method is 0.971 piece/s slower than the original method in terms of the image processing velocity. But the proposed method is still feasible, and the purpose of posture measurement is achieved.

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Earth-Rock Dam Deformation Monitoring Based on Three-Dimensional Laser Scanning Technology

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.926-930.1918 ◽

2014 ◽

Vol 926-930 ◽

pp. 1918-1921 ◽

Cited By ~ 1

Author(s):

Ju Wang ◽

Cheng Cai Zhang

Keyword(s):

Point Cloud ◽

Laser Scanning ◽

Reference Model ◽

Three Dimensional ◽

Deformation Monitoring ◽

Surface Model ◽

Point Cloud Data ◽

Cloud Data ◽

The Earth ◽

Dam Deformation

Three-dimensional laser scanning can obtain the complete geometry information of the dam quickly and accurately, and then achieve the overall deformation monitoring, which breaks the traditional limitation of single point monitoring and local monitoring. In this paper, the complete point cloud data of the dam was obtained by three-dimensional laser scanning technology, and the surface model of the earth-rock dam was constructed by three-dimensional spherical projection surface dam construction algorithm. Then the accurate three-dimensional surface model of the earth-rock dam was acquired, and the first phase of the model as reference model,with different periods of point cloud data collected were analyzed with the reference model to obtain information about the dam deformation.

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A Filtering Method for ICESat-2 Photon Point Cloud Data Based on Relative Neighboring Relationship and Local Weighted Distance Statistics

IEEE Geoscience and Remote Sensing Letters ◽

10.1109/lgrs.2020.3011215 ◽

2020 ◽

pp. 1-5

Author(s):

Yi Li ◽

Haiqiang Fu ◽

Jianjun Zhu ◽

Changcheng Wang

Keyword(s):

Point Cloud ◽

Point Cloud Data ◽

Weighted Distance ◽

Cloud Data ◽

Filtering Method

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Analysis of Efficient Visualization and Interactive Editing of 3D Point Cloud Data

TECHART Journal of Arts and Imaging Science ◽

10.15323/techart.2016.05.3.2.32 ◽

2016 ◽

Vol 3 (2) ◽

pp. 32

Author(s):

Rekha Patil ◽

Ashok Kumar Patil ◽

Youngho Chai

Keyword(s):

Point Cloud ◽

3D Point Cloud ◽

Point Cloud Data ◽

Cloud Data ◽

Interactive Editing

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Registration and Fusion of UAV LiDAR System Sequence Images and Laser Point Clouds

Journal of Imaging Science and Technology ◽

10.2352/j.imagingsci.technol.2021.65.1.01050110.2352/j.imagingsci.technol.2021.65.1.010501 ◽

2020 ◽

Author(s):

Jiayong Yu ◽

Longchen Ma ◽

Maoyi Tian, ◽

Xiushan Lu

Keyword(s):

Point Cloud ◽

Image Data ◽

Point Clouds ◽

Optical Image ◽

Point Cloud Data ◽

Feature Points ◽

Lidar System ◽

Registration Accuracy ◽

Cloud Data ◽

Intensity Image

The unmanned aerial vehicle (UAV)-mounted mobile LiDAR system (ULS) is widely used for geomatics owing to its efficient data acquisition and convenient operation. However, due to limited carrying capacity of a UAV, sensors integrated in the ULS should be small and lightweight, which results in decrease in the density of the collected scanning points. This affects registration between image data and point cloud data. To address this issue, the authors propose a method for registering and fusing ULS sequence images and laser point clouds, wherein they convert the problem of registering point cloud data and image data into a problem of matching feature points between the two images. First, a point cloud is selected to produce an intensity image. Subsequently, the corresponding feature points of the intensity image and the optical image are matched, and exterior orientation parameters are solved using a collinear equation based on image position and orientation. Finally, the sequence images are fused with the laser point cloud, based on the Global Navigation Satellite System (GNSS) time index of the optical image, to generate a true color point cloud. The experimental results show the higher registration accuracy and fusion speed of the proposed method, thereby demonstrating its accuracy and effectiveness.

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