scholarly journals A Basic Study on Data Structure and Process of Point Cloud based on Terrestrial LiDAR for Guideline of Reverse Engineering of Architectural MEP

2015 ◽  
Vol 16 (8) ◽  
pp. 5695-5706 ◽  
Author(s):  
Ji-Eun Kim ◽  
Sang-Chul Park ◽  
Tae-Wook Kang
Keyword(s):  
Data Structure ◽  
Reverse Engineering ◽  
Point Cloud ◽  
Basic Study ◽  
Terrestrial Lidar

User-Driven Computer-Assisted Reverse Engineering of Editable CAD Assembly Models

2021 ◽  
pp. 1-16
Author(s):  
Ghazanfar Ali Shah ◽  
Jean-Philippe Pernot ◽  
Arnaud Polette ◽  
Franca Giannini ◽  
Marina Monti
Keyword(s):  
Reverse Engineering ◽  
Point Cloud ◽  
Point Clouds ◽  
Geometric Constraints ◽  
Computer Assisted ◽  
Reconstruction Process ◽  
Mechanical Parts ◽  
Starting Point ◽  
Cad Models ◽  
Incomplete Datasets

Abstract This paper introduces a novel reverse engineering technique for the reconstruction of editable CAD models of mechanical parts' assemblies. The input is a point cloud of a mechanical parts' assembly that has been acquired as a whole, i.e. without disassembling it prior to its digitization. The proposed framework allows for the reconstruction of the parametric CAD assembly model through a multi-step reconstruction and fitting approach. It is modular and it supports various exploitation scenarios depending on the available data and starting point. It also handles incomplete datasets. The reconstruction process starts from roughly sketched and parameterized geometries (i.e 2D sketches, 3D parts or assemblies) that are then used as input of a simulated annealing-based fitting algorithm, which minimizes the deviation between the point cloud and the reconstructed geometries. The coherence of the CAD models is maintained by a CAD modeler that performs the updates and satisfies the geometric constraints as the fitting process goes on. The optimization process leverages a two-level filtering technique able to capture and manage the boundaries of the geometries inside the overall point cloud in order to allow for local fitting and interfaces detection. It is a user-driven approach where the user decides what are the most suitable steps and sequence to operate. It has been tested and validated on both real scanned point clouds and as-scanned virtually generated point clouds incorporating several artifacts that would appear with real acquisition devices.

Error Analysis of a Mobile Terrestrial LiDAR System

GEOMATICA ◽  
2014 ◽  
Vol 68 (3) ◽  
pp. 183-194 ◽  
Author(s):  
M. Leslar ◽  
B. Hu ◽  
J.G. Wang
Keyword(s):  
Point Cloud ◽  
Point Clouds ◽  
Sensitivity Study ◽  
Error Sources ◽  
Terrestrial Lidar ◽  
Lever Arm ◽  
Ideal Situation ◽  
Individual Variables ◽  
The Individual ◽  
Source Of Error

The understanding of the effects of error on Mobile Terrestrial LiDAR (MTL) point clouds has not increased with their popularity. In this study, comprehensive error analyses based on error propagation theory and global sensitivity study were carried out to quantitatively describe the effects of various error sources in a MTL system on the point cloud. Two scenarios were envisioned; the first using the uncertainties for measurement and calibration variables that are normally expected for MTL systems as they exist today, and the second using an ideal situation where measurement and calibration values have been well adjusted. It was found that the highest proportion of error in the point cloud can be attributed to the boresight and lever arm parameters for MTL systems calibrated using non-rigours methods. In particular, under a loosely controlled error condition, the LiDAR to INS Z lever arm and the LiDAR to INS roll angle contributed more error in the output point cloud than any other parameter, including the INS position. Under tightly controlled error conditions, the INS position became the dominant source of error in the point cloud. In addition, conditional variance analysis has shown that the majority of the error in a point cloud can be attributed to the individual variables. Errors caused by the interactions between the diverse variables are minimal and can be regarded as insignificant.

scholarly journals A HYBRID MODEL FOR THE REVERSE ENGINEERING OF THE MILAN CATHEDRAL. CHALLENGES AND LESSON LEARNT

2021 ◽  
Author(s):  
Franco Spettu ◽  
Simone Teruggi ◽  
Francesco Canali ◽  
Cristiana Achille ◽  
Francesco Fassi
Keyword(s):  
Reverse Engineering ◽  
Point Cloud ◽  
Learning Algorithm ◽  
A Priori ◽  
Point Clouds ◽  
Logical Structure ◽  
Cloud Data ◽  
Survey Techniques ◽  
Periodic Maintenance ◽  
Maintenance And Inspection

Cultural Heritage (CH) 3D digitisation is getting increasing attention and importance. Advanced survey techniques provide as output a 3D point cloud, wholly and accurately describing even the most complex architectural geometry with a priori established accuracy. These 3D point models are generally used as the base for the realisation of 2D technical drawings and 3D advanced representations. During the last 12 years, the 3DSurveyGroup (3DSG, Politecnico di Milano) conduced an omni-comprehensive, multi-technique survey, obtaining the full point cloud of Milan Cathedral, from which were produced the 2D technical drawings and the 3D model of the Main Spire used by the Veneranda Fabbrica del Duomo di Milano (VF) to plan its periodic maintenance and inspection activities on the Cathedral. Using the survey product directly to plan VF activities would help to skip a long-lasting, uneconomical and manual process of 2D and 3D technical elaboration extraction. In order to do so, the unstructured point cloud data must be enriched with semantics, providing a hierarchical structure that can communicate with a powerful, flexible information system able to effectively manage both point clouds and 3D geometries as hybrid models. For this purpose, the point cloud was segmented using a machine-learning algorithm with multi-level multi-resolution (MLMR) approach in order to obtain a manageable, reliable and repeatable dataset. This reverse engineering process allowed to identify directly on the point cloud the main architectonic elements that are then re-organised in a logical structure inserted inside the informative system built inside the 3DExperience environment, developed by Dassault Systémes.

scholarly journals INTEGRATING TERRESTRIAL LIDAR WITH POINT CLOUDS CREATED FROM UNMANNED AERIAL VEHICLE IMAGERY

2015 ◽  
Vol XL-1/W4 ◽  
pp. 97-101 ◽  
Author(s):  
M. Leslar
Keyword(s):  
Point Cloud ◽  
Inertial Navigation System ◽  
Vertical Wall ◽  
Digital Camera ◽  
Point Clouds ◽  
Digital Photogrammetry ◽  
Lidar System ◽  
Terrestrial Lidar ◽  
Stereo Imagery ◽  
Aerial Vehicle

Using unmanned aerial vehicles (UAV) for the purposes of conducting high-accuracy aerial surveying has become a hot topic over the last year. One of the most promising means of conducting such a survey involves integrating a high-resolution non-metric digital camera with the UAV and using the principals of digital photogrammetry to produce high-density colorized point clouds. Through the use of stereo imagery, precise and accurate horizontal positioning information can be produced without the need for integration with any type of inertial navigation system (INS). Of course, some form of ground control is needed to achieve this result. Terrestrial LiDAR, either static or mobile, provides the solution. Points extracted from Terrestrial LiDAR can be used as control in the digital photogrammetry solution required by the UAV. In return, the UAV is an affordable solution for filling in the shadows and occlusions typically experienced by Terrestrial LiDAR. In this paper, the accuracies of points derived from a commercially available UAV solution will be examined and compared to the accuracies achievable by a commercially available LIDAR solution. It was found that the LiDAR system produced a point cloud that was twice as accurate as the point cloud produced by the UAV’s photogrammetric solution. Both solutions gave results within a few centimetres of the control field. In addition the about of planar dispersion on the vertical wall surfaces in the UAV point cloud was found to be multiple times greater than that from the horizontal ground based UAV points or the LiDAR data.

scholarly journals FAST REGISTRATION OF TERRESTRIAL LIDAR POINT CLOUD AND SEQUENCE IMAGES

2017 ◽  
Vol XLII-2/W7 ◽  
pp. 875-879
Author(s):  
J. Shao ◽  
W. Zhang ◽  
Y. Zhu ◽  
A. Shen
Keyword(s):  
Point Cloud ◽  
Engineering Application ◽  
Image Point ◽  
Color Information ◽  
Registration Accuracy ◽  
Registration Method ◽  
Terrestrial Lidar ◽  
The Rich ◽  
Ground Based Lidar

Image has rich color information, and it can help to promote recognition and classification of point cloud. The registration is an important step in the application of image and point cloud. In order to give the rich texture and color information for LiDAR point cloud, the paper researched a fast registration method of point cloud and sequence images based on the ground-based LiDAR system. First, calculating transformation matrix of one of sequence images based on 2D image and LiDAR point cloud; second, using the relationships of position and attitude information among multi-angle sequence images to calculate all transformation matrixes in the horizontal direction; last, completing the registration of point cloud and sequence images based on the collinear condition of image point, projective center and LiDAR point. The experimental results show that the method is simple and fast, and the stitching error between adjacent images is litter; meanwhile, the overall registration accuracy is high, and the method can be used in engineering application.

The Use of the Terrestrial Photogrammetry in Reverse Engineering Applications

2015 ◽  
Vol 4 (2) ◽  
pp. 48-57
Author(s):  
Naci Yastikli ◽  
Zehra Erisir ◽  
Pelin Altintas ◽  
Tugba Cak
Keyword(s):  
Reverse Engineering ◽  
Point Cloud ◽  
Low Cost ◽  
Line Drawing ◽  
Engineering Application ◽  
3D Models ◽  
Engineering Applications ◽  
Ship Model ◽  
Dense Point ◽  
Terrestrial Photogrammetry

The reverse engineering applications has gained great momentum in industrial production with developments in the fields of computer vision and computer-aided design (CAD). The reproduction of an existing product or a spare part, reproduction of an existing surface, elimination of the defect or improvement of the available product are the goals of industrial reverse engineering applications. The first and the most important step in reverse engineering applications is the generation of the three dimensional (3D) metric model of an existing product in computer environment. After this stage, many operations such as the preparation of molds for mass production, the performance testing, the comparison of the existing product with other products and prototypes which are available on the market are performed by using the generated 3D models. In reverse engineering applications, the laser scanner system or digital terrestrial photogrammetry methods, also called contactless method, are preferred for the generation of the 3D models. In particular, terrestrial photogrammetry has become a popular method since require only photographs for the 3-dimensional drawing, the generation of the dense point cloud using the image matching algorithms and the orthoimage generation as well as its low cost. In this paper, an industrial application of 3D information modelling is presented which concerns the measurement and 3D metric modelling of the ship model. The possible usage of terrestrial photogrammetry in reverse engineering application is investigated based on low cost photogrammetric system. The main aim was the generation of the dense point cloud and 3D line drawing of the ship model by using terrestrial photogrammetry, for the production of the ship in real size as a reverse engineering application. For this purpose, the images were recorded with digital SLR camera and orientations have been performed. Then 3D line drawing operations, point cloud and orthoimage generations have been accomplished by using PhotoModeler software. As a result of the proposed terrestrial photogrammetric steps, 0.5 mm spaced dense point cloud and orthoimage have been generated. The obtained results from experimental study were discussed and possible use of proposed methods was evaluated for reverse engineering application.

Research Based on Reverse Engineering Technology of Complex Structure Product

2015 ◽  
Vol 741 ◽  
pp. 806-809
Author(s):  
Ai Qin Lin ◽  
Yong Xi He
Keyword(s):  
Reverse Engineering ◽  
Point Cloud ◽  
Complex Structure ◽  
Laser Scanner ◽  
Complex Surface ◽  
Curved Surface ◽  
Quality Model ◽  
High Quality ◽  
Engineering Technology ◽  
Working Principle

Introduced reverse engineering technology and working principle. Researched reverse design process of the complex curved surface "spider". The data were collected by means of multiple scanning measuring with laser scanner. Used Geomagic Studio software for date point cloud processed of complex curved surface. Used UG software for surface reconstruction designed. Product reduction and improvement of the design were finished rapidly and high quality. Model of spider was printed with rapid prototyping technology. Compared with physical, the model’s reliability and accuracy were verified by reverse engineering design.Keywords: complex surface; reverse engineering technology; UG; Geomagic Studio software

An efficient data structure approach for BIM-to-point-cloud change detection using modifiable nested octree

2021 ◽  
Vol 132 ◽  
pp. 103922
Author(s):  
Sangyoon Park ◽  
Sungha Ju ◽  
Sanghyun Yoon ◽  
Minh Hieu Nguyen ◽  
Joon Heo
Keyword(s):  
Data Structure ◽  
Change Detection ◽  
Point Cloud ◽  
Structure Approach ◽  
Efficient Data

Computation and Simulation of 5-Axis Cutter Based on Scattered Point Cloud Data

2012 ◽  
Vol 602-604 ◽  
pp. 1740-1743
Author(s):  
Wen Hui Zhao ◽  
She Liu
Keyword(s):  
Reverse Engineering ◽  
Distance Function ◽  
Point Cloud ◽  
Complex Surface ◽  
Conjugate Problem ◽  
Local Feature ◽  
Conjugate Points ◽  
B Spline ◽  
Cloud Data ◽  
Cad Cam

The complex surface is modeled by triangular surface, B-spline or non-uniform rational B-spline first and then the planing of the cutter is followed in reverse engineering. But this require CAD/CAM software and operator’s experiene. Because of this，the research on direct NC cutter generation from point cloud have become the focus of research in reverse engineering. The normal，curvature，surface vary et al parameters are calculated by principle component analysis method and so on, which define the local feature of the surface hidden in the point cloud. Then，based on local feature，point cloud is simplified. It is proved that two points with minimal orientation-distance on a pair of smooth surfaces are conjugate points. Thus the conjugate problem between the tool surface and the part surface is converted into optimization process of orientation-distance function. The cutter trace and the cutter interference are achieved by local and global optization of the orientation-distance function.

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