Point Clouds Pre-Processing and Surface Reconstruction Based on Tangent Continuity Algorithm Technique

2020 ◽  
Vol 38 (6A) ◽  
pp. 917-925
Author(s):  
Ali M. Al-Bdairy ◽  
Ahmed A.A. Al-Duroobi ◽  
Maan A. Tawfiq
Keyword(s):  
Case Studies ◽  
Surface Reconstruction ◽  
Laser Scanner ◽  
Point Clouds ◽  
3D Objects ◽  
Data Points ◽  
3D Scanners ◽  
Different Shapes ◽  
Noise Factors

Pre-processing is essential for processing the row data point clouds which acquired using a 3D laser scanner as a modern technique to digitize and reconstruct the surface of the 3D objects in reverse engineering applications. Due to the accuracy limitation of some 3D scanners and the environmental noise factors such as illumination and reflection, there are some noised data points associated with the row point clouds, so, in the present paper, a preprocessing algorithm has been proposed to determine and delete the unnecessary data as noised points and save the remaining data points for the surface reconstruction of 3D objects from its point clouds which acquired using the 3D laser scanner (Matter and Form). The proposed algorithm based on the assessment of tangent continuity as a geometrical feature and criteria for the contiguous points. A MATLAB software has been used to construct a program for the proposed point clouds pre-processing algorithm, the validity of the constructed program has been proved using geometrical case studies with different shapes. The application results of the proposed tangent algorithm and surface fitting process for the suggested case studies were proved the validity of the proposed algorithm for simplification of the point clouds, where the percent of noised data which removed according to the proposed tangent continuity algorithm which achieved a reduction of the total points to a percentage of (43.63%), and (32.01%) for the studied case studies, from the total number of data points in point cloud for first and second case study respectively.

scholarly journals Pre-Processing and Surface Reconstruction of Points Cloud Based on Chord Angle Algorithm Technique

2020 ◽  
Vol 16 (3) ◽  
pp. 34-42
Author(s):  
Ali M. Albdairy ◽  
Ahmed A. A. Al-Duroobi ◽  
Maan A. Tawfiq
Keyword(s):  
Case Studies ◽  
Point Cloud ◽  
Rapid Development ◽  
Laser Scanner ◽  
Modern Technology ◽  
Mathematical Representation ◽  
Adjacent Pair ◽  
3D Objects ◽  
Laser Scanners ◽  
Data Points

Abstract Although the rapid development in reverse engineering techniques, 3D laser scanners can be considered the modern technology used to digitize the 3D objects, but some troubles may be associate this process due to the environmental noises and limitation of the used scanners. So, in the present paper a data pre-processing algorithm has been proposed to obtain the necessary geometric features and mathematical representation of scanned object from its point cloud which obtained using 3D laser scanner (Matter and Form) through isolating the noised points. The proposed algorithm based on continuous calculations of chord angle between each adjacent pair of points in point cloud. A MATLAB program has been built to perform the proposed algorithm which implemented using a suggested case studies with cylinder and dome shape. The resulted point cloud from application the proposed algorithm and result of surface fitting for the case studies has been proved the proficiency of the proposed chord angle algorithm in pre-processing of data points and clean the point cloud, where the percent of data which was ignored as noisy data points according to proposed chord angle algorithm was arrived to (81.52%) and (75.01%)of total number of data points in point cloud for first and second case study respectively.

scholarly journals Towards footwear manufacturing 4.0: shoe sole robotic grasping in assembling operations

2021 ◽  
Author(s):  
Guillermo Oliver ◽  
Pablo Gil ◽  
Jose F. Gomez ◽  
Fernando Torres
Keyword(s):  
Industry 4.0 ◽  
Laser Scanner ◽  
Point Clouds ◽  
Average Score ◽  
Low Density ◽  
Contour Extraction ◽  
Shoe Industry ◽  
Simulated Environment ◽  
Dense Point ◽  
Different Shapes

AbstractIn this paper, we present a robotic workcell for task automation in footwear manufacturing such as sole digitization, glue dispensing, and sole manipulation from different places within the factory plant. We aim to make progress towards shoe industry 4.0. To achieve it, we have implemented a novel sole grasping method, compatible with soles of different shapes, sizes, and materials, by exploiting the particular characteristics of these objects. Our proposal is able to work well with low density point clouds from a single RGBD camera and also with dense point clouds obtained from a laser scanner digitizer. The method computes antipodal grasping points from visual data in both cases and it does not require a previous recognition of sole. It relies on sole contour extraction using concave hulls and measuring the curvature on contour areas. Our method was tested both in a simulated environment and in real conditions of manufacturing at INESCOP facilities, processing 20 soles with different sizes and characteristics. Grasps were performed in two different configurations, obtaining an average score of 97.5% of successful real grasps for soles without heel made with materials of low or medium flexibility. In both cases, the grasping method was tested without carrying out tactile control throughout the task.

scholarly journals Estimating parameter values of a socio-hydrological flood model

2018 ◽  
Vol 379 ◽  
pp. 193-198
Author(s):  
Marlies Holkje Barendrecht ◽  
Alberto Viglione ◽  
Heidi Kreibich ◽  
Sergiy Vorogushyn ◽  
Bruno Merz ◽  
...  
Keyword(s):  
Time Series ◽  
Case Studies ◽  
Hydrological Model ◽  
Promising Tool ◽  
Flood Model ◽  
Modelling Studies ◽  
Data Points ◽  
Few Data ◽  
Parameter Values

Abstract. Socio-hydrological modelling studies that have been published so far show that dynamic coupled human-flood models are a promising tool to represent the phenomena and the feedbacks in human-flood systems. So far these models are mostly generic and have not been developed and calibrated to represent specific case studies. We believe that applying and calibrating these type of models to real world case studies can help us to further develop our understanding about the phenomena that occur in these systems. In this paper we propose a method to estimate the parameter values of a socio-hydrological model and we test it by applying it to an artificial case study. We postulate a model that describes the feedbacks between floods, awareness and preparedness. After simulating hypothetical time series with a given combination of parameters, we sample few data points for our variables and try to estimate the parameters given these data points using Bayesian Inference. The results show that, if we are able to collect data for our case study, we would, in theory, be able to estimate the parameter values for our socio-hydrological flood model.

scholarly journals The city model as a tool for participatory urban planning – a case study: The Bilotti open air museum of Cosenza

2014 ◽  
Vol II-5 ◽  
pp. 25-32
Author(s):  
S. Artese
Keyword(s):  
Urban Planning ◽  
Laser Scanner ◽  
Point Clouds ◽  
Web Gis ◽  
Scale Model ◽  
3D City Model ◽  
City Model ◽  
The City ◽  
Citizen’S Participation

The paper describes the implementation of the 3D city model of the pedestrian area of Cosenza, which in recent years has become the Bilotti Open Air Museum (MAB). For this purpose were used both the data available (regional technical map, city maps, orthophotos) and acquired through several surveys of buildings and "Corso Mazzini" street (photos, topographic measurements, laser scanner point clouds). In addition to the urban scale model, the survey of the statues of the MAB was carried out. By means of data processing, the models of the same statues have been created, that can be used as objects within the city model. <br><br> The 3D model of the MAB open air museum has been used to implement a Web-GIS allowing the citizen's participation, understanding and suggestions. The 3D city model is intended as a new tool for urban planning, therefore it has been used both for representing the current situation of the MAB and for design purposes, by acknowledging suggestions regarding a possible different location of the statues and a new way to enjoy the museum.

scholarly journals GUIDELINES FOR AUTHORS PREPARING A FULL PAPER TO BE SUBMITTED TO ISPRS EVENTS

2021 ◽  
Vol XLIII-B2-2021 ◽  
pp. 613-618
Author(s):  
P. Ortiz-Coder ◽  
R. Cabecera
Keyword(s):  
Case Studies ◽  
3D Model ◽  
Laser Scanner ◽  
Point Clouds ◽  
Model Generation ◽  
Selection Algorithm ◽  
Full Paper ◽  
Historical Heritage ◽  
The Moment ◽  
New Generation

Abstract. In recent years, a new generation of instruments has appeared that are motion-based capture. These systems are based on a combination of techniques, among which LIDAR stands out. In this article we present a new proposal for a 3D model generation instrument based on videogrammetry. The prototype designed consists of two cameras connected to a computer system. One of the cameras is in charge of running VisualSLAM and guiding the user in real time at the moment of data acquisition; the other camera, with a higher resolution, saves the images and, thanks to a refined 3D-Based frame selection algorithm, processes them using automatic photogrammetric procedures, generating one or more point-clouds that are integrated to give way to a high-density and high-precision 3D colour point-cloud.The paper evaluates the proposal with four case studies: two of an urban nature and two related to historical heritage. The resulting models are confronted with the Faro Focus3D X330 laser scanner, classic photogrammetric procedures with reflex camera and Agisoft metashape software and are also confronted with precision points measured with a total station. The case studies show that the proposed system has a high capture speed, and that the accuracy of the models can be competitive in many areas of professional surveying and can be a viable alternative for the creation of instruments based on videogrammetry.

scholarly journals Rockfall monitoring by Terrestrial Laser Scanning – case study of the basaltic rock face at Castellfollit de la Roca (Catalonia, Spain)

2011 ◽  
Vol 11 (3) ◽  
pp. 829-841 ◽  
Author(s):  
A. Abellán ◽  
J. M. Vilaplana ◽  
J. Calvet ◽  
D. García-Sellés ◽  
E. Asensio
Keyword(s):  
Urban Areas ◽  
Laser Scanning ◽  
Mass Movement ◽  
Laser Scanner ◽  
Point Clouds ◽  
Basaltic Rock ◽  
Historical Record ◽  
Rock Face ◽  
The Village

Abstract. This case study deals with a rock face monitoring in urban areas using a Terrestrial Laser Scanner. The pilot study area is an almost vertical, fifty meter high cliff, on top of which the village of Castellfollit de la Roca is located. Rockfall activity is currently causing a retreat of the rock face, which may endanger the houses located at its edge. TLS datasets consist of high density 3-D point clouds acquired from five stations, nine times in a time span of 22 months (from March 2006 to January 2008). The change detection, i.e. rockfalls, was performed through a sequential comparison of datasets. Two types of mass movement were detected in the monitoring period: (a) detachment of single basaltic columns, with magnitudes below 1.5 m3 and (b) detachment of groups of columns, with magnitudes of 1.5 to 150 m3. Furthermore, the historical record revealed (c) the occurrence of slab failures with magnitudes higher than 150 m3. Displacements of a likely slab failure were measured, suggesting an apparent stationary stage. Even failures are clearly episodic, our results, together with the study of the historical record, enabled us to estimate a mean detachment of material from 46 to 91.5 m3 year−1. The application of TLS considerably improved our understanding of rockfall phenomena in the study area.

scholarly journals INDOOR MODELLING FROM SLAM-BASED LASER SCANNER: DOOR DETECTION TO ENVELOPE RECONSTRUCTION

2017 ◽  
Vol XLII-2/W7 ◽  
pp. 345-352 ◽  
Author(s):  
L. Díaz-Vilariño ◽  
E. Verbree ◽  
S. Zlatanova ◽  
A. Diakité
Keyword(s):  
Point Cloud ◽  
Minimum Energy ◽  
Laser Scanner ◽  
Point Clouds ◽  
Cloud Data ◽  
Indoor Space ◽  
Combined Use ◽  
Global Configuration ◽  
Envelope Reconstruction

Updated and detailed indoor models are being increasingly demanded for various applications such as emergency management or navigational assistance. The consolidation of new portable and mobile acquisition systems has led to a higher availability of 3D point cloud data from indoors. In this work, we explore the combined use of point clouds and trajectories from SLAM-based laser scanner to automate the reconstruction of building indoors. The methodology starts by door detection, since doors represent transitions from one indoor space to other, which constitutes an initial approach about the global configuration of the point cloud into building rooms. <br><br> For this purpose, the trajectory is used to create a vertical point cloud profile in which doors are detected as local minimum of vertical distances. As point cloud and trajectory are related by time stamp, this feature is used to subdivide the point cloud into subspaces according to the location of the doors. The correspondence between subspaces and building rooms is not unambiguous. One subspace always corresponds to one room, but one room is not necessarily depicted by just one subspace, for example, in case of a room containing several doors and in which the acquisition is performed in a discontinue way. The labelling problem is formulated as combinatorial approach solved as a minimum energy optimization. Once the point cloud is subdivided into building rooms, envelop (conformed by walls, ceilings and floors) is reconstructed for each space. The connectivity between spaces is included by adding the previously detected doors to the reconstructed model. The methodology is tested in a real case study.

scholarly journals AUGMENTED REALITY FOR CULTURAL HERITAGE: THE REBIRTH OF A HISTORICAL SQUARE

2019 ◽  
Vol XLII-2/W17 ◽  
pp. 303-308
Author(s):  
A. Scianna ◽  
G. F. Gaglio ◽  
M. La Guardia
Keyword(s):  
Augmented Reality ◽  
Rapid Prototyping ◽  
Cultural Heritage ◽  
Laser Scanner ◽  
Point Clouds ◽  
New Methods ◽  
Study Case ◽  
3D Information ◽  
Architectural Barriers

Abstract. The case study, faced in this paper, arises in the context of Interreg Italia-Malta European project named I-Access, dedicated to the improvement of accessibility to Cultural Heritage (CH). Accessibility considered not only as the demolition of physical architectural barriers, but also as the possibility of fruition of CH through technological tools that can increase its perception and knowledge. Last achievements in photogrammetry and terrestrial laser scanner (TLS) technology offered new methods of data acquisition in the field of CH, giving the possibility of monitoring and processing big data, in the form of point clouds. Ever in this field, reverse engineering techniques and computer graphics are even more used for involving visitors to discover CH, with navigation into 3D reconstructions, empowering the real visualization adding further 3D information through the Augmented Reality (AR). At the same time, recent advances on rapid prototyping technologies grant the automated 3D printing of scaled 3D model reconstructions of real CH elements allowing the tactile fruition of visitors that suffer from visual defects and the connection with 3D AR visualizations. The presented work shows how these technologies could revive an historical square, the Piazza Garraffo in Palermo (Italy), with the virtual insertion of its baroque fountain, originally placed there. The final products of this work are an indoor and an outdoor AR mobile application, that allow the visualization of the historical original asset of the square. This study case shows how the mixing of AR and the rapid prototyping technologies could be useful for the improvement of the fruition of CH. This work could be considered a multidisciplinary experimentation, where different technologies, today still in development, contribute to the same goal aimed at improving the accessibility of the monument for enhancing the fruition of CH.

Error Propagation in Digital Additive Remanufacturing Process Planning

2019 ◽  
Author(s):  
Mojahed Alkhateeb ◽  
Jeremy L. Rickli ◽  
Nicholas J. Christoforou
Keyword(s):  
Error Propagation ◽  
Point Cloud ◽  
Point Clouds ◽  
Propagation Model ◽  
Smoothing Factor ◽  
Material Deposition ◽  
Proposed Model ◽  
Data Points ◽  
3D Scanners ◽  
The Right

Abstract A point cloud is a digital representation of a part that consists of a set of data points in space. Typically point clouds are produced by 3D scanners that hover above a part and records points in a large number that represent the external surface of a part. Additive remanufacturing offers a sustainable solution to end-of-use (EoU) core disposal and recovery and requires quantification of part damage or wear that requires reprocessing. This paper proposes an error propagation approach that models the interaction of each step of the additive remanufacturing process. This proposed model is formulated, and the results of the errors generated from the parameters of the scanner and point cloud smoothing are presented. Smoothing is an important step to reduce the noises generated from scanning, knowing the right smoothing factor is important since over smoothing results in dimensional inaccuracies and errors, especially in cores with smaller degrees of damage. It is important to know the error generated from scanning and point cloud smoothing to compensate in the following steps and generate appropriate material deposition paths. Inaccuracies in the 3D model renders can impact the remainder of the additive remanufacturing accuracy, especially because there are multiple steps in the process. Sources of error from smoothing, meshing, slicing, and material deposition are proposed in the error propagation model for additive remanufacturing. Results of efforts to quantify the scanning and smoothing steps within this model are presented.

scholarly journals The Combined Use of SLAM Laser Scanning and TLS for the 3D Indoor Mapping

Buildings ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 386
Author(s):  
Aino Keitaanniemi ◽  
Juho-Pekka Virtanen ◽  
Petri Rönnholm ◽  
Antero Kukko ◽  
Toni Rantanen ◽  
...  
Keyword(s):  
Indoor Environment ◽  
Laser Scanning ◽  
Laser Scanner ◽  
Point Clouds ◽  
Information Modeling ◽  
Mapping Strategy ◽  
Localization And Mapping ◽  
Combined Use ◽  
Building Information

An efficient 3D survey of a complex indoor environment remains a challenging task, especially if the accuracy requirements for the geometric data are high for instance in building information modeling (BIM) or construction. The registration of non-overlapping terrestrial laser scanning (TLS) point clouds is laborious. We propose a novel indoor mapping strategy that uses a simultaneous localization and mapping (SLAM) laser scanner (LS) to support the building-scale registration of non-overlapping TLS point clouds in order to reconstruct comprehensive building floor/3D maps. This strategy improves efficiency since it allows georeferenced TLS data to only be collected from those parts of the building that require such accuracy. The rest of the building is measured with SLAM LS accuracy. Based on the results of the case study, the introduced method can locate non-overlapping TLS point clouds with an accuracy of 18–51 mm using target sphere comparison.

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