Development of a Computer Vision Tracking System for Automated 3D Reconstruction of Concrete Bridges

2014 ◽  
Author(s):  
Andrea Zanoni ◽  
Giacomo Maninetti ◽  
Federico Cheli ◽  
Marco Garozzo
Keyword(s):  
Computer Vision ◽  
3D Reconstruction ◽  
Laser Scanning ◽  
Tracking System ◽  
Laser Scanner ◽  
Experimental Tests ◽  
Body Motion ◽  
Digital Data ◽  
Vision Measurement ◽  
Position And Orientation

Concrete bridge inspection is nowadays primarily a slow, subjective, non-comprehensive and costly set of procedures. Automation of the acquisition method is especially desirable for economical and repeatability reasons. Digital data is normally derived from well established non-destructive testing techniques, high resolution cameras and, more recently, by 3D laser scanning. This latter technique has some advantageous aspects in terms of reliability, repeatability, completeness and intuitiveness of the analysis of the resulting 3D reconstruction of the concrete structure. Statical laser scanning is, though, impractical for a variety of different reasons. A possible way of overcoming such difficulties is represented by dynamical measurement, achieved by moving in a prescribed manner the laser scanner during the scanning process. This procedure, on the other hand, requires a reliable tracking system for the laser scanner position and orientation. This work focuses on the development of such system, based primarily on computer vision measurement systems. A compact and lightweight 3D laser scanner has been placed on an automated carrier able to move along a standard inspection by-bridge, and a system of cameras and transducers has been designed to measure the carrier position and orientation based on the assumption of rigid body motion of the by-bridge multi-link arm during inspection operations. Several experimental tests have been performed to assess the viability of the proposed system and to evaluate its performance.

3D Reconstruction and Visual Simulation of Double-Flowered Plants Based on Laser Scanning

2019 ◽  
Vol 33 (10) ◽  
pp. 1955013
Author(s):  
Dongna Cai ◽  
Zhi Li ◽  
Yongjian Huai
Keyword(s):  
Computer Vision ◽  
3D Reconstruction ◽  
Laser Scanning ◽  
Three Dimensional ◽  
Morphological Structure ◽  
Digital Data ◽  
Visual Simulation ◽  
Cloud Data ◽  
Virtual Plant ◽  
Vision Simulation

Flower plants have become a major difficulty in virtual plant research because of their rich external morphological structure and complex physiological processes. Computer vision simulation provides powerful tools for exploring powerful biological systems and operating laws. In this paper, Chrysanthemum and Chinese rose, double flowers as the symbolic flowers of Beijing, are chosen as the study subject. On the basis of maximizing the protection of flower growth structure, an effective method based on laser scanning for three-dimensional (3D) reconstruction and visual simulation of flower plants is proposed. This method uses laser technology to scan the sample and store it as point cloud data. After applying a series of image analysis and processing techniques such as splicing, denoising, repairing and color correction, the digital data optimized by the sample is obtained accurately and efficiently, and a highly realistic 3D simulation model of the plant is formed. The results of the research indicate that it is a convenient research method for the 3D reconstruction of flower plants and computer vision simulation of virtual plants. It also provides an effective way for in-depth study of scientific experiments and digital protection of rare and endangered plants.

3D Reconstruction of Mining Area Based on Terrestrial Laser Scanner and Calculation of Extraction

2013 ◽  
Vol 325-326 ◽  
pp. 1787-1791 ◽  
Author(s):  
Hang Chen ◽  
Zhang Ying ◽  
Zhen Feng Shao ◽  
Zhi Qiang Du
Keyword(s):  
3D Reconstruction ◽  
Laser Scanning ◽  
3D Model ◽  
Laser Scanner ◽  
Terrestrial Laser Scanning ◽  
Mining Area ◽  
New Method ◽  
Terrestrial Laser Scanner ◽  
Surveying And Mapping

This paper analyzes the characteristics of terrestrial laser scanning technology and it's advantages of surveying and mapping application in mining area. Through the analysis of the specific topographical features of mining area, we design a new method in measurement based on the terrestrial laser scanning technology, and probe into the methods of 3D reconstruction and calculation of extraction. Experiments show that the proposed method can improve the efficiency of surveying and mapping in mining area , the 3D model can be used to monitor the extraction of mining area.

scholarly journals THE USE OF COMPUTER VISION ALGORITHMS FOR AUTOMATIC ORIENTATION OF TERRESTRIAL LASER SCANNING DATA

2016 ◽  
Vol XLI-B3 ◽  
pp. 315-322 ◽  
Author(s):  
Jakub Stefan Markiewicz
Keyword(s):  
Computer Vision ◽  
Laser Scanning ◽  
Laser Scanner ◽  
Terrestrial Laser Scanning ◽  
Depth Map ◽  
Point Clouds ◽  
Terrestrial Laser Scanner ◽  
Key Points ◽  
Source Data ◽  
Panoramic Images

The paper presents analysis of the orientation of terrestrial laser scanning (TLS) data. In the proposed data processing methodology, point clouds are considered as panoramic images enriched by the depth map. Computer vision (CV) algorithms are used for orientation, which are applied for testing the correctness of the detection of tie points and time of computations, and for assessing difficulties in their implementation. The BRISK, FASRT, MSER, SIFT, SURF, ASIFT and CenSurE algorithms are used to search for key-points. The source data are point clouds acquired using a Z+F 5006h terrestrial laser scanner on the ruins of Iłża Castle, Poland. Algorithms allowing combination of the photogrammetric and CV approaches are also presented.

scholarly journals 3D RECONSTRUCTION OF THE <i>ROMAN DOMUS</i> IN THE ARCHAEOLOGICAL SITE OF <i>LYLIBAEUM</i> (MARSALA, ITALY)

2019 ◽  
Vol XLII-2/W15 ◽  
pp. 437-442
Author(s):  
D. Ebolese ◽  
M. Lo Brutto ◽  
G. Dardanelli
Keyword(s):  
3D Reconstruction ◽  
Laser Scanning ◽  
Laser Scanner ◽  
Terrestrial Laser Scanning ◽  
Archaeological Site ◽  
Technological Evolution ◽  
Laser Scanners ◽  
Scan Registration ◽  
High Level ◽  
Data Acquisition Strategy

<p><strong>Abstract.</strong> Generally, terrestrial laser scanning surveys involve a rather large number of scans to ensure a high percentage of overlap required for the scan registration phase (target-based or point-based registration, cloud-to-cloud registration). These approaches result in data redundancy that could slow down both the acquisition and post-processing phases. In recent years, the technological evolution in the field of laser scanners has been directed to the development of devices that are able to perform an onsite pre-registration, to optimize the survey procedures and the reliability of the registration of the scan. The paper presents the results achieved during a terrestrial laser scanning survey carried out for the documentation and 3D reconstruction of the large and complex archaeological remains of the so-called Roman <i>Domus</i> in the archaeological site of <i>Lylibaeum</i> (Marsala, Italy). The survey was also conducted using a terrestrial laser scanner capable of pre-registering scans using a topographic approach. The pre-registration procedure and the data acquisition strategy have allowed to optimize the workflow and to obtain a 3D model of the Roman <i>Domus</i> with a high level of detail and area coverage.</p>

scholarly journals Wide-Angle, Monocular Head Tracking using Passive Markers

2021 ◽  
Author(s):  
Balazs P Vagvolgyi ◽  
Ravikrishnan P Jayakumar ◽  
Manu S Madhav ◽  
James J Knierim ◽  
Noah Cowan
Keyword(s):  
Computer Vision ◽  
3D Reconstruction ◽  
Visual Information ◽  
Small Animal ◽  
Wide Field ◽  
Head Tracking ◽  
Single Camera ◽  
Wide Range ◽  
Position And Orientation ◽  
Set Up

Camera images can encode large amounts of visual information of an animal and its environment, enabling high fidelity 3D reconstruction of the animal and its environment using computer vision methods. Most systems, both markerless (e.g. deep learning based) and marker-based, require multiple cameras to track features across multiple points of view to enable such 3D reconstruction. However, such systems can be expensive and are challenging to set up in small animal research apparatuses. We present an open-source, marker-based system for tracking the head of a rodent for behavioral research that requires only a single camera with a potentially wide field of view. The system features a lightweight visual target and computer vision algorithms that together enable high-accuracy tracking of the six-degree-of-freedom position and orientation of the animal's head. The system, which only requires a single camera positioned above the behavioral arena, robustly reconstructs the pose over a wide range of head angles (360 degrees in yaw, and approximately +/-120 degrees in roll and pitch). Experiments with live animals demonstrate that the system can reliably identifyrat head position and orientation. Evaluations using a commercial optical tracker device show that the system achieves accuracy that rivals commercial multi-camera systems. Our solution significantly improves upon existing monocular marker-based tracking methods, both in accuracy and in allowable range of motion. The proposed system enables the study of complex behaviors by providing robust, fine-scale measurements of rodent head motions in a wide range of orientations.

scholarly journals THE USE OF COMPUTER VISION ALGORITHMS FOR AUTOMATIC ORIENTATION OF TERRESTRIAL LASER SCANNING DATA

2016 ◽  
Vol XLI-B3 ◽  
pp. 315-322
Author(s):  
Jakub Stefan Markiewicz
Keyword(s):  
Computer Vision ◽  
Laser Scanning ◽  
Laser Scanner ◽  
Terrestrial Laser Scanning ◽  
Depth Map ◽  
Point Clouds ◽  
Terrestrial Laser Scanner ◽  
Key Points ◽  
Source Data ◽  
Panoramic Images

The paper presents analysis of the orientation of terrestrial laser scanning (TLS) data. In the proposed data processing methodology, point clouds are considered as panoramic images enriched by the depth map. Computer vision (CV) algorithms are used for orientation, which are applied for testing the correctness of the detection of tie points and time of computations, and for assessing difficulties in their implementation. The BRISK, FASRT, MSER, SIFT, SURF, ASIFT and CenSurE algorithms are used to search for key-points. The source data are point clouds acquired using a Z+F 5006h terrestrial laser scanner on the ruins of Iłża Castle, Poland. Algorithms allowing combination of the photogrammetric and CV approaches are also presented.

Results of studying the dimensional accuracy of the bases of complete removable prostheses made using 3D printing and traditional technologies

2020 ◽  
pp. 34-39
Author(s):  
Vokulova Yu.A. Vokulova ◽  
E.N. Zhulev
Keyword(s):  
3D Printing ◽  
Traditional Method ◽  
Laser Scanning ◽  
Laser Scanner ◽  
Digital Technologies ◽  
Dimensional Accuracy ◽  
3D Printer ◽  
Significance Level ◽  
Average Value ◽  
The Difference

This article presents the results of studying the dimensional accuracy of the bases of complete removable prostheses made using a 3D printer and the traditional method. Bases of complete removable prostheses were made using an intraoral laser scanner iTero Cadent (USA) and a 3D printer Asiga Max UV (Australia). To study the dimensional accuracy of the bases of complete removable prostheses, we used the DentalCAD 2.2 Valletta software. The Nonparametric Wilcoxon W-test was used for statistical analysis of the obtained data. We found that the average value of the difference with the standard for bases made using digital technologies is 0.08744±0.0484 mm. The average value of the difference with the standard for bases made by the traditional method is 0.5654±0.1611 mm. Based on these data, we concluded that the bases of complete removable prostheses made using modern digital technologies (intraoral laser scanning and 3D printer) have a higher dimensional accuracy compared to the bases of complete removable prostheses made using the traditional method with a significance level of p<0.05 (Wilcoxon's W-test=0, p=0.031). Keywords: digital technologies in dentistry, digital impressions, intraoral scanner, 3D printing, ExoCAD, complete removable dentures.

scholarly journals Estimation of Vegetation-Induced Flow Resistance for Hydraulic Computations Using Airborne Laser Scanning Data

Water ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 1864
Author(s):  
Peter Mewis
Keyword(s):  
Laser Scanning ◽  
Flow Resistance ◽  
Laser Scanner ◽  
Airborne Laser Scanning ◽  
Density Parameter ◽  
Vegetation Density ◽  
Airborne Laser Scanner ◽  
Airborne Laser ◽  
Bed Roughness ◽  
Available Information

The effect of vegetation in hydraulic computations can be significant. This effect is important for flood computations. Today, the necessary terrain information for flood computations is obtained by airborne laser scanning techniques. The quality and density of the airborne laser scanning information allows for more extensive use of these data in flow computations. In this paper, known methods are improved and combined into a new simple and objective procedure to estimate the hydraulic resistance of vegetation on the flow in the field. State-of-the-art airborne laser scanner information is explored to estimate the vegetation density. The laser scanning information provides the base for the calculation of the vegetation density parameter ωp using the Beer–Lambert law. In a second step, the vegetation density is employed in a flow model to appropriately account for vegetation resistance. The use of this vegetation parameter is superior to the common method of accounting for the vegetation resistance in the bed resistance parameter for bed roughness. The proposed procedure utilizes newly available information and is demonstrated in an example. The obtained values fit very well with the values obtained in the literature. Moreover, the obtained information is very detailed. In the results, the effect of vegetation is estimated objectively without the assignment of typical values. Moreover, a more structured flow field is computed with the flood around denser vegetation, such as groups of bushes. A further thorough study based on observed flow resistance is needed.

Computer vision measurement system for standards calibration in XY plane with sub-micrometer accuracy

2019 ◽  
Vol 105 (1-4) ◽  
pp. 1531-1537 ◽  
Author(s):  
Pedro Bastos Costa ◽  
Fabiana Rodrigues Leta ◽  
Felipe de Oliveira Baldner
Keyword(s):  
Computer Vision ◽  
Measurement System ◽  
Vision Measurement
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