The influence of surface topology on the quality of the point cloud data acquired with laser line scanning probe

Sensor Review ◽  
2014 ◽  
Vol 34 (3) ◽  
pp. 255-265 ◽  
Author(s):  
Syed Hammad Mian ◽  
Mohammed Abdul Mannan ◽  
Abdulrahman M. Al-Ahmari
Keyword(s):  
Point Cloud ◽  
Laser Scanning ◽  
Specular Reflection ◽  
Surface Characteristics ◽  
Laser Line ◽  
Scanning Probe ◽  
Surface Topology ◽  
Polished Surface ◽  
Content Type ◽  
Line Scanning

Purpose – The purpose of this paper is to investigate the influence of surface topology on the performance of laser line scanning probe and to suggest methodology for 3D digitization of specular surfaces. Design/methodology/approach – Two different molds, one having milled surface and the other with polished surface, were used to identify effect of surface characteristics on the performance of laser line scanning probe mounted on bridge-type coordinate measuring machine. The point cloud data acquisition of two surfaces was carried out using different combinations of laser scanning parameters. The point cloud sets thus obtained were analyzed in terms of completeness, noise and accuracy. The polished mold which exhibited specular reflection was digitized at different scanning angles of laser line scanning probe using the best combination of scanning parameters. Findings – Results confirmed that surface characteristics play important role to determine quality of the reverse engineering (RE) process. The results in terms of completeness, accuracy and noise for point cloud sets have successfully been obtained for milled and polished surfaces. Three-dimensional (3D) comparison analysis suggested larger deviation in cases of polished surface as compared to milled surface. The point cloud set acquired with proposed approach was better in terms of both completeness and noise reduction. Originality/value – There has been an increased demand for measurement of metallic, polished and shiny surfaces in automotive, aerospace and medical industries. These surfaces are very difficult to scan because they exhibit specular reflection instead of diffuse reflection. Laser line scanning probe which is a non-contact method is in great demand for RE. This is due to the fact that it possesses very high data acquisition speed. However, laser scanning is hugely affected by surface characteristics which in turn govern specular reflection.In this paper, it has been shown that a surface that exhibits various degrees of specular reflection can be digitized efficiently if appropriate combination of scanning parameters and positions of laser line scanning probe are used. Also, this paper has attempted to offer a procedure to overcome incompleteness and noise in 3D data as obtained by the laser line scanning probe.

Research on the High Precision Laser Line Scanning Measuring System

2007 ◽  
Vol 339 ◽  
pp. 131-135 ◽  
Author(s):  
Jian Jun Ding ◽  
Zhuang De Jiang ◽  
Bing Li ◽  
Jun Jie Guo
Keyword(s):  
High Precision ◽  
Laser Scanning ◽  
Laser Line ◽  
Measuring System ◽  
Surface Measurement ◽  
Iteration Algorithm ◽  
Reconstruction Method ◽  
Loop Feedback ◽  
Axis Position ◽  
Line Scanning

Rapid reverse technology is one of the key technologies with which the enterprises develop new product and occupy the market rapidly. How to realize the reverse measurement and CAD geometry reconstruction rapidly and accurately is always the most important focus for the researchers. Based on the laser scanning technology, the realization principle of the laser line scanning measuring system is presented and the approaches to improve the precision are also analysed in the paper. The self-adaptation adjustment of the probe position can move the light knife image to the optimal imaging area of the CCD according to the calibration result, which will ensure the measurement precision of the CCD image. With the inner velocity loop and outer position loop feedback control, the simple axis position precision of the mechanical system can be controlled within 5um. In order to pick up the points of the light knife centre rationally and exactly, the reconstruction-disperse iteration algorithm is put forward. After processed by different iteration times, the optimal points can be obtained. The reconstruction method of curve and surface based on NURBS is also given. The paper presents the application and realization of the system at last, which realizes the curve and surface measurement with high precision.

A new pose estimation method for non-cooperative spacecraft based on point cloud

2019 ◽  
Vol 12 (1) ◽  
pp. 23-41 ◽  
Author(s):  
Zhiming Chen ◽  
Lei Li ◽  
Yunhua Wu ◽  
Bing Hua ◽  
Kang Niu
Keyword(s):  
Pose Estimation ◽  
Point Cloud ◽  
Laser Scanning ◽  
Rapid Development ◽  
Estimation Method ◽  
Life Extension ◽  
Laser Radar ◽  
Quality Of Data ◽  
Proximity Space ◽  
Content Type

Purpose On-orbit service technology is one of the key technologies of space manipulation activities such as spacecraft life extension, fault spacecraft capture, on-orbit debris removal and so on. It is known that the failure satellites, space debris and enemy spacecrafts in space are almost all non-cooperative targets. Relatively accurate pose estimation is critical to spatial operations, but also a recognized technical difficulty because of the undefined prior information of non-cooperative targets. With the rapid development of laser radar, the application of laser scanning equipment is increasing in the measurement of non-cooperative targets. It is necessary to research a new pose estimation method for non-cooperative targets based on 3D point cloud. The paper aims to discuss these issues. Design/methodology/approach In this paper, a method based on the inherent characteristics of a spacecraft is proposed for estimating the pose (position and attitude) of the spatial non-cooperative target. First, we need to preprocess the obtained point cloud to reduce noise and improve the quality of data. Second, according to the features of the satellite, a recognition system used for non-cooperative measurement is designed. The components which are common in the configuration of satellite are chosen as the recognized object. Finally, based on the identified object, the ICP algorithm is used to calculate the pose between two frames of point cloud in different times to finish pose estimation. Findings The new method enhances the matching speed and improves the accuracy of pose estimation compared with traditional methods by reducing the number of matching points. The recognition of components on non-cooperative spacecraft directly contributes to the space docking, on-orbit capture and relative navigation. Research limitations/implications Limited to the measurement distance of the laser radar, this paper considers the pose estimation for non-cooperative spacecraft in the close range. Practical implications The pose estimation method for non-cooperative spacecraft in this paper is mainly applied to close proximity space operations such as final rendezvous phase of spacecraft or ultra-close approaching phase of target capture. The system can recognize components needed to be capture and provide the relative pose of non-cooperative spacecraft. The method in this paper is more robust compared with the traditional single component recognition method and overall matching method when scanning of laser radar is not complete or the components are blocked. Originality/value This paper introduces a new pose estimation method for non-cooperative spacecraft based on point cloud. The experimental results show that the proposed method can effectively identify the features of non-cooperative targets and track their position and attitude. The method is robust to the noise and greatly improves the speed of pose estimation while guarantee the accuracy.

Structural assessment using terrestrial laser scanning point clouds

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Linh Truong-Hong ◽  
Roderik Lindenbergh ◽  
Thu Anh Nguyen
Keyword(s):  
Point Cloud ◽  
Laser Scanning ◽  
Noisy Data ◽  
Point Clouds ◽  
Reference Surface ◽  
Content Type ◽  
Mixed Pixels ◽  
Data Points ◽  
The Impact

PurposeTerrestrial laser scanning (TLS) point clouds have been widely used in deformation measurement for structures. However, reliability and accuracy of resulting deformation estimation strongly depends on quality of each step of a workflow, which are not fully addressed. This study aims to give insight error of these steps, and results of the study would be guidelines for a practical community to either develop a new workflow or refine an existing one of deformation estimation based on TLS point clouds. Thus, the main contributions of the paper are investigating point cloud registration error affecting resulting deformation estimation, identifying an appropriate segmentation method used to extract data points of a deformed surface, investigating a methodology to determine an un-deformed or a reference surface for estimating deformation, and proposing a methodology to minimize the impact of outlier, noisy data and/or mixed pixels on deformation estimation.Design/methodology/approachIn practice, the quality of data point clouds and of surface extraction strongly impacts on resulting deformation estimation based on laser scanning point clouds, which can cause an incorrect decision on the state of the structure if uncertainty is available. In an effort to have more comprehensive insight into those impacts, this study addresses four issues: data errors due to data registration from multiple scanning stations (Issue 1), methods used to extract point clouds of structure surfaces (Issue 2), selection of the reference surface Sref to measure deformation (Issue 3), and available outlier and/or mixed pixels (Issue 4). This investigation demonstrates through estimating deformation of the bridge abutment, building and an oil storage tank.FindingsThe study shows that both random sample consensus (RANSAC) and region growing–based methods [a cell-based/voxel-based region growing (CRG/VRG)] can be extracted data points of surfaces, but RANSAC is only applicable for a primary primitive surface (e.g. a plane in this study) subjected to a small deformation (case study 2 and 3) and cannot eliminate mixed pixels. On another hand, CRG and VRG impose a suitable method applied for deformed, free-form surfaces. In addition, in practice, a reference surface of a structure is mostly not available. The use of a fitting plane based on a point cloud of a current surface would cause unrealistic and inaccurate deformation because outlier data points and data points of damaged areas affect an accuracy of the fitting plane. This study would recommend the use of a reference surface determined based on a design concept/specification. A smoothing method with a spatial interval can be effectively minimize, negative impact of outlier, noisy data and/or mixed pixels on deformation estimation.Research limitations/implicationsDue to difficulty in logistics, an independent measurement cannot be established to assess the deformation accuracy based on TLS data point cloud in the case studies of this research. However, common laser scanners using the time-of-flight or phase-shift principle provide point clouds with accuracy in the order of 1–6 mm, while the point clouds of triangulation scanners have sub-millimetre accuracy.Practical implicationsThis study aims to give insight error of these steps, and the results of the study would be guidelines for a practical community to either develop a new workflow or refine an existing one of deformation estimation based on TLS point clouds.Social implicationsThe results of this study would provide guidelines for a practical community to either develop a new workflow or refine an existing one of deformation estimation based on TLS point clouds. A low-cost method can be applied for deformation analysis of the structure.Originality/valueAlthough a large amount of the studies used laser scanning to measure structure deformation in the last two decades, the methods mainly applied were to measure change between two states (or epochs) of the structure surface and focused on quantifying deformation-based TLS point clouds. Those studies proved that a laser scanner could be an alternative unit to acquire spatial information for deformation monitoring. However, there are still challenges in establishing an appropriate procedure to collect a high quality of point clouds and develop methods to interpret the point clouds to obtain reliable and accurate deformation, when uncertainty, including data quality and reference information, is available. Therefore, this study demonstrates the impact of data quality in a term of point cloud registration error, selected methods for extracting point clouds of surfaces, identifying reference information, and available outlier, noisy data and/or mixed pixels on deformation estimation.

Precise on-line non-target pose measurement for cylindrical components based on laser scanning

2019 ◽  
Vol 39 (4) ◽  
pp. 596-606 ◽  
Author(s):  
Jieyu Zhang ◽  
Yuanying Qiu ◽  
Xuechao Duan ◽  
Changqi Yang
Keyword(s):  
Point Cloud ◽  
Laser Scanning ◽  
Synthesis Method ◽  
Side Surface ◽  
3D Vision ◽  
Scanning Method ◽  
Content Type ◽  
New Synthesis ◽  
Surface Damages ◽  
On Line

Purpose Cylindrical components are common in industry assembly areas. It is necessary to obtain their precise positions and orientations for their assemblies. But some measurement approaches relying on measuring targets are not allowed, as they may not meet the efficiency requirement of on-line measurement or may cause surface damages to the components. Thus, this paper aims to provide a precise on-line non-target scanning method based on 3D vision. Design/methodology/approach First, a laser profile sensor is used to acquire point cloud of the side surface of the measured cylindrical component. Then a composite process is conducted to estimate the pose and position of the axis. Aiming at this purpose, two fitting approaches, i.e., axis fitting and generatrix fitting, are tried respectively to estimate the pose parameters from the point cloud. Findings The results of Monte Carlo simulations demonstrate that neither the axis fitting nor the generatrix fitting could solely obtain the needed accuracy and precisions roundly. Thus, a new synthesis method is presented. And the results of prototype experiments validate the excellent accuracy and precision of the synthesis method. Originality/value This proposed new synthesis method combines the advantages of both the above fitting methods and can be easily integrated into the assembly line to guide the automation assembly process of the cylindrical components precisely.

scholarly journals POINT CLOUD ANALYSIS FOR CONSERVATION AND ENHANCEMENT OF MODERNIST ARCHITECTURE

2017 ◽  
Vol XLII-2/W3 ◽  
pp. 71-77 ◽  
Author(s):  
M. Balzani ◽  
F. Maietti ◽  
B. Mugayar Kühl
Keyword(s):  
Cultural Heritage ◽  
Point Cloud ◽  
Laser Scanning ◽  
Cloud Model ◽  
Geometric Model ◽  
Laser Scanner ◽  
Surface Characteristics ◽  
3D Modelling ◽  
Advanced Analysis ◽  
Acquisition Processes

Documentation of cultural assets through improved acquisition processes for advanced 3D modelling is one of the main challenges to be faced in order to address, through digital representation, advanced analysis on shape, appearance and conservation condition of cultural heritage. 3D modelling can originate new avenues in the way tangible cultural heritage is studied, visualized, curated, displayed and monitored, improving key features such as analysis and visualization of material degradation and state of conservation. An applied research focused on the analysis of surface specifications and material properties by means of 3D laser scanner survey has been developed within the project of Digital Preservation of FAUUSP building, Faculdade de Arquitetura e Urbanismo da Universidade de São Paulo, Brazil. The integrated 3D survey has been performed by the DIAPReM Center of the Department of Architecture of the University of Ferrara in cooperation with the FAUUSP. The 3D survey has allowed the realization of a point cloud model of the external surfaces, as the basis to investigate in detail the formal characteristics, geometric textures and surface features. The digital geometric model was also the basis for processing the intensity values acquired by laser scanning instrument; this method of analysis was an essential integration to the macroscopic investigations in order to manage additional information related to surface characteristics displayable on the point cloud.

Simplified Expression of Point Cloud Data and STL File Generation Method Based on Laser Line Scanning Mode

2015 ◽  
Vol 52 (10) ◽  
pp. 101003
Author(s):  
姚春荣 Yao Chunrong ◽  
陈兆学 Chen Zhaoxue ◽  
安美君 An Meijun ◽  
王远军 Wang Yuanjun
Keyword(s):  
Point Cloud ◽  
Laser Line ◽  
Point Cloud Data ◽  
Cloud Data ◽  
Stl File ◽  
Line Scanning

scholarly journals Integration of point cloud data and hyperspectral imaging as a data gathering methodology for refurbishment projects using building information modelling (BIM)

2019 ◽  
Vol 17 (1) ◽  
pp. 57-75 ◽  
Author(s):  
Kinjiro Amano ◽  
Eric C.W. Lou ◽  
Rodger Edwards
Keyword(s):  
Hyperspectral Imaging ◽  
Point Cloud ◽  
Laser Scanning ◽  
Spatial Information ◽  
Data Gathering ◽  
Facilities Management ◽  
Building Information Modelling ◽  
Content Type ◽  
Cloud Data ◽  
Building Information

Purpose Building information modelling (BIM) is a digital representation of the physical and functional characteristics of a building. Its use offers a range of benefits in terms of achieving the efficient design, construction, operation and maintenance of buildings. Applying BIM at the outset of a new build project should be relatively easy. However, it is often problematic to apply BIM techniques to an existing building, for example, as part of a refurbishment project or as a tool supporting the facilities management strategy, because of inadequacies in the previous management of the dataset that characterises the facility in question. These inadequacies may include information on as built geometry and materials of construction. By the application of automated retrospective data gathering for use in BIM, such problems should be largely overcome and significant benefits in terms of efficiency gains and cost savings should be achieved. Design/methodology/approach Laser scanning can be used to collect geometrical and spatial information in the form of a 3D point cloud, and this technique is already used. However, as a point cloud representation does not contain any semantic information or geometrical context, such point cloud data must refer to external sources of data, such as building specification and construction materials, to be in used in BIM. Findings Hyperspectral imaging techniques can be applied to provide both spectral and spatial information of scenes as a set of high-resolution images. Integrating of a 3D point cloud into hyperspectral images would enable accurate identification and classification of surface materials and would also convert the 3D representation to BIM. Originality/value This integrated approach has been applied in other areas, for example, in crop management. The transfer of this approach to facilities management and construction would improve the efficiency and automation of the data transition from building pathology to BIM. In this study, the technological feasibility and advantages of the integration of laser scanning and hyperspectral imaging (the latter not having previously been used in the construction context in its own right) is discussed, and an example of the use of a new integration technique is presented, applied for the first time in the context of buildings.

Development of the 3D dome model based on a terrestrial laser scanner

2018 ◽  
Vol 36 (2) ◽  
pp. 122-136 ◽  
Author(s):  
Abdul Fatah Firdaus Abu Hanipah ◽  
Khairul Nizam Tahar
Keyword(s):  
Point Cloud ◽  
Laser Scanning ◽  
3D Model ◽  
Laser Scanner ◽  
Terrestrial Laser Scanner ◽  
Model Assessment ◽  
Point Cloud Data ◽  
Data Set ◽  
Content Type ◽  
Cloud Data

Purpose Laser scanning technique is used to measure and model objects using point cloud data generated laser pulses. Conventional techniques to construct 3D models are time consuming, costly and need more manpower. The purpose of this paper is to assess the 3D model of the Sultan Salahuddin Abdul Aziz Shah Mosque’s main dome using a terrestrial laser scanner. Design/methodology/approach A laser scanner works through line of sight, which indicates that multiple scans need to be taken from a different view to ensure a complete data set. Targets must spread in all directions, and targets should be placed on fixed structures and flat surfaces for the normal scan and fine scan. After the scanning operation, point cloud data from the laser scanner were cleaned and registered before a 3D model could be developed. Findings As a result, the reconstruction of the 3D model was successfully developed. The samples are based on the triangle dimension, curve line, horizontal dimension and vertical dimension at the dome. The standard deviation and accuracy are calculated based on the comparison of the 21 samples taken between the high-resolution and low-resolution scanning data. Originality/value There are many ways to develop the 3D model and based on this study, the less complex ways also produce the best result. The authors implement the different types of dimensions for the 3D model assessment, which have not yet been considered in the past.

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