scholarly journals Space Subdivision of Indoor Mobile Laser Scanning Data Based on the Scanner Trajectory

2018 ◽  
Vol 10 (11) ◽  
pp. 1815 ◽  
Author(s):  
Ahmed Elseicy ◽  
Shayan Nikoohemat ◽  
Michael Peter ◽  
Sander Oude Elberink

State-of-the-art indoor mobile laser scanners are now lightweight and portable enough to be carried by humans. They allow the user to map challenging environments such as multi-story buildings and staircases while continuously walking through the building. The trajectory of the laser scanner is usually discarded in the analysis, although it gives insight about indoor spaces and the topological relations between them. In this research, the trajectory is used in conjunction with the point cloud to subdivide the indoor space into stories, staircases, doorways, and rooms. Analyzing the scanner trajectory as a standalone dataset is used to identify the staircases and to separate the stories. Also, the doors that are traversed by the operator during the scanning are identified by processing only the interesting spots of the point cloud with the help of the trajectory. Semantic information like different space labels is assigned to the trajectory based on the detected doors. Finally, the point cloud is semantically enriched by transferring the labels from the annotated trajectory to the full point cloud. Four real-world datasets with a total of seven stories are used to evaluate the proposed methods. The evaluation items are the total number of correctly detected rooms, doors, and staircases.

Author(s):  
Avar Almukhtar ◽  
Henry Abanda ◽  
Zaid O. Saeed ◽  
Joseph H.M. Tah

The urgent need to improve performance in the construction industry has led to the adoption of many innovative technologies. 3D laser scanners are amongst the leading technologies being used to capture and process assets or construction project data for use in various applications. Due to its nascent nature, many questions are still unanswered about 3D laser scanning, which in turn contribute to the slow adaptation of the technology. Some of these include the role of 3D laser scanners in capturing and processing raw construction project data. How accurate is the 3D laser scanner or point cloud data? How does laser scanning fit with other wider emerging technologies such as Building Information Modelling (BIM)? This study adopts a proof-of-concept approach, which in addition to answering the afore-mentioned questions, illustrates the application of the technology in practice. The study finds that the quality of the data, commonly referred to as point cloud data is still a major issue as it depends on the distance between the target object and 3D laser scanner’s station. Additionally, the quality of the data is still very dependent on data file sizes and the computational power of the processing machine. Lastly, the connection between laser scanning and BIM approaches is still weak as what can be done with a point cloud data model in a BIM environment is still very limited. The aforementioned findings reinforce existing views on the use of 3D laser scanners in capturing and processing construction project data.


Author(s):  
Abdul Qadir Bhatti ◽  
◽  
Abdul Wahab ◽  
Wadea Sindi ◽  
◽  
...  

Laser scanning is a fast-developing technology, which collects millions of points and creates a framework within a few minutes, generating a 'point cloud' of the structure. Laser scanning is a quite new but rapidly evolving technology that has been reviewed. this research study has used most modern models of laser scanners and their accompanying software that are capable of accurate capture and alignment of point clouds. Consequently, the laser scans have precisely captured the current geometry of each structure, which is irregular in many cases due to inherently complex geometry, anomalies during the original construction, aging, deterioration, and structural damage. As both the exterior and interior of the structure have been scanned, the point cloud became a digital 3D image of the historical building, which can be virtually toured from inside and outside. A 4-story public building was scanned using a 3D laser scanner to determine the architectural and structural drawings of the response to an earthquake. The application of passive control using a damper with the laser scanner has been modelled in this study. The results corroborate that this technique provides the best outcomes for reducing seismic damage collapses.


Author(s):  
O. Ajioka ◽  
Y. Hori

Mosaic floors of surviving buildings in Ostia have been mainly recorded in photographs. From 2008, Japanese research group carries out a project of 3d measuring of the whole structure of ancient Roman city Ostia using laser scanners, including its landscape, city blocks, streets, buildings, wall paintings and mosaics. The laser scanner allows for a more detailed analysis and a greater potential for recording mosaics. We can record the data of mosaics, which are described piece by piece. However it is hard to acquire enough high dense point cloud and the internal camera of the laser scanner produce low quality images. We introduce a possible technology of 3D recording of mosaics with high-quality colour information; SFM. The use of this technique permits us to create 3D models from images provided from a CCD camera without heavy and large laser scanners. We applied SFM system to different three types of the mosaics laid down on the floors of "the House of the Dioscuroi", "the Insula of the Muse" and "the House of Jove and Ganymede", and created high resolution orthographic images. Then we examined to compare these orthographic images with that are created from the point cloud data. As a result, we confirmed that SFM system has sufficient practical utility for the mosaic research. And we present how much of density of point cloud or ground resolution are required for the documentation of mosaics accurately.


2019 ◽  
Vol 952 (10) ◽  
pp. 47-54
Author(s):  
A.V. Komissarov ◽  
A.V. Remizov ◽  
M.M. Shlyakhova ◽  
K.K. Yambaev

The authors consider hand-held laser scanners, as a new photogrammetric tool for obtaining three-dimensional models of objects. The principle of their work and the newest optical systems based on various sensors measuring the depth of space are described in detail. The method of simultaneous navigation and mapping (SLAM) used for combining single scans into point cloud is outlined. The formulated tasks and methods for performing studies of the DotProduct (USA) hand-held laser scanner DPI?8X based on a test site survey are presented. The accuracy requirements for determining the coordinates of polygon points are given. The essence of the performed experimental research of the DPI?8X scanner is described, including scanning of a test object at various scanner distances, shooting a test polygon from various scanner positions and building point cloud, repeatedly shooting the same area of the polygon to check the stability of the scanner. The data on the assessment of accuracy and analysis of research results are given. Fields of applying hand-held laser scanners, their advantages and disadvantages are identified.


Sensors ◽  
2021 ◽  
Vol 21 (10) ◽  
pp. 3493
Author(s):  
Gahyeon Lim ◽  
Nakju Doh

Remarkable progress in the development of modeling methods for indoor spaces has been made in recent years with a focus on the reconstruction of complex environments, such as multi-room and multi-level buildings. Existing methods represent indoor structure models as a combination of several sub-spaces, which are constructed by room segmentation or horizontal slicing approach that divide the multi-room or multi-level building environments into several segments. In this study, we propose an automatic reconstruction method of multi-level indoor spaces with unique models, including inter-room and inter-floor connections from point cloud and trajectory. We construct structural points from registered point cloud and extract piece-wise planar segments from the structural points. Then, a three-dimensional space decomposition is conducted and water-tight meshes are generated with energy minimization using graph cut algorithm. The data term of the energy function is expressed as a difference in visibility between each decomposed space and trajectory. The proposed method allows modeling of indoor spaces in complex environments, such as multi-room, room-less, and multi-level buildings. The performance of the proposed approach is evaluated for seven indoor space datasets.


2021 ◽  
Vol 10 (2) ◽  
pp. 90
Author(s):  
Jin Zhu ◽  
Dayu Cheng ◽  
Weiwei Zhang ◽  
Ci Song ◽  
Jie Chen ◽  
...  

People spend more than 80% of their time in indoor spaces, such as shopping malls and office buildings. Indoor trajectories collected by indoor positioning devices, such as WiFi and Bluetooth devices, can reflect human movement behaviors in indoor spaces. Insightful indoor movement patterns can be discovered from indoor trajectories using various clustering methods. These methods are based on a measure that reflects the degree of similarity between indoor trajectories. Researchers have proposed many trajectory similarity measures. However, existing trajectory similarity measures ignore the indoor movement constraints imposed by the indoor space and the characteristics of indoor positioning sensors, which leads to an inaccurate measure of indoor trajectory similarity. Additionally, most of these works focus on the spatial and temporal dimensions of trajectories and pay less attention to indoor semantic information. Integrating indoor semantic information such as the indoor point of interest into the indoor trajectory similarity measurement is beneficial to discovering pedestrians having similar intentions. In this paper, we propose an accurate and reasonable indoor trajectory similarity measure called the indoor semantic trajectory similarity measure (ISTSM), which considers the features of indoor trajectories and indoor semantic information simultaneously. The ISTSM is modified from the edit distance that is a measure of the distance between string sequences. The key component of the ISTSM is an indoor navigation graph that is transformed from an indoor floor plan representing the indoor space for computing accurate indoor walking distances. The indoor walking distances and indoor semantic information are fused into the edit distance seamlessly. The ISTSM is evaluated using a synthetic dataset and real dataset for a shopping mall. The experiment with the synthetic dataset reveals that the ISTSM is more accurate and reasonable than three other popular trajectory similarities, namely the longest common subsequence (LCSS), edit distance on real sequence (EDR), and the multidimensional similarity measure (MSM). The case study of a shopping mall shows that the ISTSM effectively reveals customer movement patterns of indoor customers.


Author(s):  
J.-F. Hullo

We propose a complete methodology for the fine registration and referencing of kilo-station networks of terrestrial laser scanner data currently used for many valuable purposes such as 3D as-built reconstruction of Building Information Models (BIM) or industrial asbuilt mock-ups. This comprehensive target-based process aims to achieve the global tolerance below a few centimetres across a 3D network including more than 1,000 laser stations spread over 10 floors. This procedure is particularly valuable for 3D networks of indoor congested environments. In situ, the use of terrestrial laser scanners, the layout of the targets and the set-up of a topographic control network should comply with the expert methods specific to surveyors. Using parametric and reduced Gauss-Helmert models, the network is expressed as a set of functional constraints with a related stochastic model. During the post-processing phase inspired by geodesy methods, a robust cost function is minimised. At the scale of such a data set, the complexity of the 3D network is beyond comprehension. The surveyor, even an expert, must be supported, in his analysis, by digital and visual indicators. In addition to the standard indicators used for the adjustment methods, including Baarda’s reliability, we introduce spectral analysis tools of graph theory for identifying different types of errors or a lack of robustness of the system as well as <i>in fine</i> documenting the quality of the registration.


2021 ◽  
Vol 13 (19) ◽  
pp. 3796
Author(s):  
Lei Fan ◽  
Yuanzhi Cai

Laser scanning is a popular means of acquiring the indoor scene data of buildings for a wide range of applications concerning indoor environment. During data acquisition, unwanted data points beyond the indoor space of interest can also be recorded due to the presence of openings, such as windows and doors on walls. For better visualization and further modeling, it is beneficial to filter out those data, which is often achieved manually in practice. To automate this process, an efficient image-based filtering approach was explored in this research. In this approach, a binary mask image was created and updated through mathematical morphology operations, hole filling and connectively analysis. The final mask obtained was used to remove the data points located outside the indoor space of interest. The application of the approach to several point cloud datasets considered confirms its ability to effectively keep the data points in the indoor space of interest with an average precision of 99.50%. The application cases also demonstrate the computational efficiency (0.53 s, at most) of the approach proposed.


2021 ◽  
Vol 12 (24) ◽  
pp. 115
Author(s):  
Diego Francisco García-Molina ◽  
Ramón González-Merino ◽  
Jesús Rodero-Pérez ◽  
Bartolomé Carrasco-Hurtado

<p class="VARKeywords">One of the main objectives of heritage management policies is to promote measures aimed at the maintenance, restoration and enhancement of cultural and archaeological assets. To guarantee this, the responsible institutions must promote actions for the dissemination and transference of cultural heritage, as well as promoting actions with the greatest possible rigour, developing scientific and technical studies that support and improve intervention methods. Recent technological advances in fields such as photogrammetry, digital terrestrial scanning and 3D modelling have made a significant contribution to the digital preservation and dissemination of architectural heritage.</p><p class="VARKeywords">European administrations, in their desire of regional development, as well as the central or local governments have notably boosted the recovery of their rich and diverse heritage. A particular case is Priego de Cordoba’s Castle, a stronghold which was one of the most important monumental icons of the Andalusian period.</p><p class="VARKeywords">Currently, this site is the main target of many architectural interventions and a model due to the implementation of last generation techniques in digital preservation. The local archaeological department promotes a large number of interventions and archaeological excavations. This has made a priority to get a qualitative geometrical 3D documentation, and therefore a constantly updated the point cloud (xyzRGB).</p><p class="VARKeywords">This paper is focussed on presenting the results of the digital preservation process through 2D planimetry obtained from photogrammetric technics, 3D models, and geospatial data. These techniques are a previous step to large architectonical intervention planned in Priego de Cordoba’s Castle, in particular, the identified structures as Wall 1 and Tower 1.</p><p class="VARKeywords">Two out of the three studied structures can be found in Wall 1. They correspond to a cobblestone pavement located in the rampart of the Wall 1, which is a post-medieval period; a double-stepped semi-underground path, excavated in the infill of the wall. The third structure studied in this paper consists of a well, which drills vertically the infill of the wall of the Tower 1. This feature is interpreted in the last research as a vertical well to place the weights of the clock sited in this tower until the 19th century.</p><p class="VARKeywords">This work combines two techniques of geometric documentation to obtain a more complete point cloud. The terrestrial laser scanning, and the photogrammetry due to the higher colour performance, along with the completion of the point cloud obtained with the laser scanner. Along with this study, we will analyse the features which will better define the best technique to fit the documentation of the different structures. Their geometric characteristics, the incidence of sunlight or the accessibility will condition the use and choice of the technique.</p><p class="VARKeywords">We have stated that there is software nowadays which makes it easier to access and consult the information through new computing hardware. Besides, we have highlighted the importance of knowledge and synergy from the different stakeholders implied (city council, technological centre and private companies). The final goal consists of making the society aware of the capital importance of digital preservation as well as dissemination of science.</p>


2020 ◽  
Vol 12 (22) ◽  
pp. 3796
Author(s):  
Maria Rashidi ◽  
Masoud Mohammadi ◽  
Saba Sadeghlou Kivi ◽  
Mohammad Mehdi Abdolvand ◽  
Linh Truong-Hong ◽  
...  

Over the last decade, particular interest in using state-of-the-art emerging technologies for inspection, assessment, and management of civil infrastructures has remarkably increased. Advanced technologies, such as laser scanners, have become a suitable alternative for labor intensive, expensive, and unsafe traditional inspection and maintenance methods, which encourage the increasing use of this technology in construction industry, especially in bridges. This paper aims to provide a thorough mixed scientometric and state-of-the-art review on the application of terrestrial laser scanners (TLS) in bridge engineering and explore investigations and recommendations of researchers in this area. Following the review, more than 1500 research publications were collected, investigated and analyzed through a two-fold literature search published within the last decade from 2010 to 2020. Research trends, consisting of dominated sub-fields, co-occurrence of keywords, network of researchers and their institutions, along with the interaction of research networks, were quantitatively analyzed. Moreover, based on the collected papers, application of TLS in bridge engineering and asset management was reviewed according to four categories including (1) generation of 3D model, (2) quality inspection, (3) structural assessment, and (4) bridge information modeling (BrIM). Finally, the paper identifies the current research gaps, future directions obtained from the quantitative analysis, and in-depth discussions of the collected papers in this area.


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