scholarly journals Accelerated Multi-View Stereo for 3D Reconstruction of Transmission Corridor with Fine-Scale Power Line

2021 ◽  
Vol 13 (20) ◽  
pp. 4097
Author(s):  
Wei Huang ◽  
San Jiang ◽  
Sheng He ◽  
Wanshou Jiang
Keyword(s):  
3D Reconstruction ◽  
High Efficiency ◽  
Depth Map ◽  
Power Line ◽  
Power Lines ◽  
Selection Strategy ◽  
Processing Unit ◽  
Fine Scale ◽  
Dense Matching ◽  
Matching Cost

Fast reconstruction of power lines and corridors is a critical task in UAV (unmanned aerial vehicle)-based inspection of high-voltage transmission corridors. However, recent dense matching algorithms suffer the problem of low efficiency when processing large-scale high-resolution UAV images. This study proposes an efficient dense matching method for the 3D reconstruction of highvoltage transmission corridors with fine-scale power lines. First, an efficient random red-black checkerboard propagation is proposed, which utilizes the neighbor pixels with the most similar color to propagate plane parameters. To combine the pixel-wise view selection strategy adopted in Colmap with the efficient random red-black checkerboard propagation, the updating schedule for inferring visible probability is improved; second, strategies for decreasing the number of matching cost computations are proposed, which can reduce the unnecessary hypotheses for verification. The number of neighbor pixels necessary to propagate plane parameters is reduced with the increase of iterations, and the number of the combinations of depth and normal is reduced for the pixel with better matching cost in the plane refinement step; third, an efficient GPU (graphics processing unit)- based depth map fusion method is proposed, which employs a weight function based on the reprojection errors to fuse the depth map. Finally, experiments are conducted by using three UAV datasets, and the results indicate that the proposed method can maintain the completeness of power line reconstruction with high efficiency when compared to other PatchMatch-based methods. In addition, two benchmark datasets are used to verify that the proposed method can achieve a better F1 score, 4–7 times faster than Colmap. 

scholarly journals Research on 3D Reconstruction Technology of Power Line Based on Image Semantic Segmentation

2021 ◽  
Vol 2095 (1) ◽  
pp. 012015
Author(s):  
Xionggang Li ◽  
Feng Zhang ◽  
Guoqiang Li ◽  
Dongwei Xiang ◽  
Chengcheng Yang
Keyword(s):  
Neural Network ◽  
3D Reconstruction ◽  
Three Dimensional ◽  
Semantic Segmentation ◽  
High Accuracy ◽  
Power Line ◽  
Power Lines ◽  
Three Dimensional Reconstruction ◽  
Dimensional Reconstruction ◽  
Depth Learning

Abstract Because it was difficult to distinguish the characteristics of the power lines by the traditional methods of extracting the power lines, which led to the current situation of incomplete reconstruction and a large number of noise in the process of rebuilding the power lines only by the inclined photographing. In this paper, the power line information in the image is segmented pixel by pixel by introducing in-depth learning semantics segmenting neural network. The three-dimensional coordinates of the power line are calculated by the principle of multi-view three-dimensional reconstruction. Finally, the power line is fitted by the catenary equation to complete the incomplete power line reconstruction. The results show that the fitted power line model has high accuracy and meets the requirements of power related applications. Based on the traditional three-dimensional reconstruction, a new idea for power line reconstruction is proposed.

scholarly journals 3D Reconstruction of Power Lines Using UAV Images to Monitor Corridor Clearance

2020 ◽  
Vol 12 (22) ◽  
pp. 3698
Author(s):  
Elżbieta Pastucha ◽  
Edyta Puniach ◽  
Agnieszka Ścisłowicz ◽  
Paweł Ćwiąkała ◽  
Witold Niewiem ◽  
...  
Keyword(s):  
3D Reconstruction ◽  
Point Cloud ◽  
Laser Scanning ◽  
Power Line ◽  
Power Lines ◽  
Spatial Distance ◽  
Surface Model ◽  
Verification Methods ◽  
Comparison Results ◽  
Uav Images

Regular power line inspections are essential to ensure the reliability of electricity supply. The inspections of overground power submission lines include corridor clearance monitoring and fault identification. The power lines corridor is a three-dimensional space around power cables defined by a set distance. Any obstacles breaching this space should be detected, as they potentially threaten the safety of the infrastructure. Corridor clearance monitoring is usually performed either by a labor-intensive total station survey (TS), terrestrial laser scanning (TLS), or expensive airborne laser scanning (ALS) from a plane or a helicopter. This paper proposes a method that uses unmanned aerial vehicle (UAV) images to monitor corridor clearance. To maintain the adequate accuracy of the relative position of wires in regard to surrounding obstacles, the same data were used both to reconstruct a point cloud representation of a digital surface model (DSM) and a 3D power line. The proposed algorithm detects power lines in a series of images using decorrelation stretch for initial image processing, the modified Prewitt filter for edge enhancement, random sample consensus (RANSAC) with additional parameters for line fitting, and epipolar geometry for 3D reconstruction. DSM points intruding into the corridor are then detected by calculating the spatial distance between a reconstructed power line and the DSM point cloud representation. Problematic objects are localized by segmenting points into voxels and then subsequent clusterization. The processing results were compared to the results of two verification methods—TS and TLS. The comparison results show that the proposed method can be used to survey power lines with an accuracy consistent with that of classical measurements.

scholarly journals Comparison of Screening Configurations for the Mitigation of Voltages and Currents Induced on Pipelines by HVAC Power Lines

Energies ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3855
Author(s):  
Arturo Popoli ◽  
Leonardo Sandrolini ◽  
Andrea Cristofolini
Keyword(s):  
Finite Element Analysis ◽  
Cross Sections ◽  
Detrimental Effect ◽  
Power Line ◽  
Skin Depth ◽  
Power Lines ◽  
Element Analysis ◽  
3D Finite Element ◽  
Different Shapes ◽  
High Magnetic Permeability

In this paper, a strategy for reducing the electromagnetic interferences induced by power lines on metallic pipelines is proposed and numerically investigated. The study considers a set of steel conductors interposed between the power line and the pipeline. Different shapes of conductor cross sections and different magnetic permeabilities are considered, to identify the solution exhibiting the greatest mitigation efficiency for the same amount of material. The investigation is carried out by means of a quasi-3D finite element analysis. Results show that the main mechanism responsible for the mitigation is constituted by the currents induced in the screening conductors by the power line. Hence, a high magnetic permeability can have a detrimental effect since it reduces the skin depth to values below the size of the screening conductor. In this case, a reduction of the screening current and in the mitigation efficiency is observed. Nevertheless, the study shows that the use of strip-shaped screening conductors allows the employment of cheaper magnetic materials without compromising the mitigation efficacy of the screening conductors.

“These Power Lines Make Me Ill”: A Typology of Residents’ Health Responses to a New High-Voltage Power Line

Risk Analysis ◽  
2017 ◽  
Vol 37 (12) ◽  
pp. 2276-2288 ◽  
Author(s):  
Jarry T. Porsius ◽  
Liesbeth Claassen ◽  
Fred Woudenberg ◽  
Tjabe Smid ◽  
Danielle R. M. Timmermans
Keyword(s):  
High Voltage ◽  
Power Line ◽  
Power Lines

scholarly journals Dynamic Line Rating—An Effective Method to Increase the Safety of Power Lines

2021 ◽  
Vol 11 (2) ◽  
pp. 492
Author(s):  
Levente Rácz ◽  
Bálint Németh
Keyword(s):  
Expert System ◽  
Electric Field ◽  
High Voltage ◽  
Low Frequency ◽  
Power Line ◽  
Power Lines ◽  
Design Parameters ◽  
Monitoring Methods ◽  
Limit Value ◽  
Potential Applications

Exceeding the electric field’s limit value is not allowed in the vicinity of high-voltage power lines because of both legal and safety aspects. The design parameters of the line must be chosen so that such cases do not occur. However, analysis of several operating power lines in Europe found that the electric field strength in many cases exceeds the legally prescribed limit for the general public. To illustrate this issue and its importance, field measurement and finite element simulation results of the low-frequency electric field are presented for an active 400 kV power line. The purpose of this paper is to offer a new, economical expert system based on dynamic line rating (DLR) that utilizes the potential of real-time power line monitoring methods. The article describes the expert system’s strengths and benefits from both technical and financial points of view, highlighting DLR’s potential for application. With our proposed expert system, it is possible to increase a power line’s safety and security by ensuring that the electric field does not exceed its limit value. In this way, the authors demonstrate that DLR has other potential applications in addition to its capacity-increasing effect in the high voltage grid.

scholarly journals Power line routing and configuration as major drivers of collision risk in two bustard species

Oryx ◽  
2020 ◽  
pp. 1-10 ◽  
Author(s):  
Ana Teresa Marques ◽  
Ricardo C. Martins ◽  
João Paulo Silva ◽  
Jorge M. Palmeirim ◽  
Francisco Moreira
Keyword(s):  
Abiotic Factors ◽  
Bird Species ◽  
Power Line ◽  
Power Lines ◽  
Mitigation Measures ◽  
Suitable Habitat ◽  
Collision Risk ◽  
Great Bustard ◽  
Line Configuration ◽  
Tetrax Tetrax

Abstract Collision with power lines is a major cause of mortality for many bird species. Understanding the biotic and abiotic factors that increase collision risk is therefore important for implementing mitigation measures to minimize mortality, such as power line rerouting or wire marking. Here, we used collision events registered during 2003–2015 along 280 km of transmission power lines in southern Portugal to analyse spatio-temporal patterns and collision risk factors in two sympatric, threatened, and collision-prone species: the great bustard Otis tarda and the little bustard Tetrax tetrax. The occurrence of collisions was not uniform across space and time, and variations could be explained by the species' ecological requirements, distribution patterns and behaviour. Although both species fly considerable distances between areas of suitable habitat, collisions were far more likely in power line sections with > 20% (for the little bustard) or > 50% (for the great bustard) of open farmland habitat in the surroundings. Power line configuration was also important: taller pylons and those with a higher number of wire levels posed a higher risk for both species. Wire marking had a small but significant effect for the little bustard, reducing collisions risk. There was, however, no similar effect for the great bustard, possibly a result of limited data. Mitigation measures should be implemented to prevent bustard collisions, including adequate route planning, ideally avoiding areas with > 20% of open habitat. Line configuration and wire marking are particularly important where such localities cannot be avoided and power lines cross areas with a high proportion of bustard habitat, including outside protected areas.

scholarly journals A comparison of semiglobal and local dense matching algorithms for surface reconstruction

2014 ◽  
Vol XL-5 ◽  
pp. 187-194 ◽  
Author(s):  
E. Dall'Asta ◽  
R. Roncella
Keyword(s):  
Computer Vision ◽  
Stereo Matching ◽  
Least Square ◽  
Stereo Image ◽  
Dense Matching ◽  
Consistency Constraints ◽  
Global Matching ◽  
Matching Cost ◽  
Software Codes ◽  
Matching Techniques

Encouraged by the growing interest in automatic 3D image-based reconstruction, the development and improvement of robust stereo matching techniques is one of the most investigated research topic of the last years in photogrammetry and computer vision.<br><br> The paper is focused on the comparison of some stereo matching algorithms (local and global) which are very popular both in photogrammetry and computer vision. In particular, the Semi-Global Matching (SGM), which realizes a pixel-wise matching and relies on the application of consistency constraints during the matching cost aggregation, will be discussed.<br><br> The results of some tests performed on real and simulated stereo image datasets, evaluating in particular the accuracy of the obtained digital surface models, will be presented. Several algorithms and different implementation are considered in the comparison, using freeware software codes like MICMAC and OpenCV, commercial software (e.g. Agisoft PhotoScan) and proprietary codes implementing Least Square e Semi-Global Matching algorithms. The comparisons will also consider the completeness and the level of detail within fine structures, and the reliability and repeatability of the obtainable data.

scholarly journals ITERATIVE REFINEMENT FOR UNDERWATER 3D RECONSTRUCTION: APPLICATION TO DISPOSED UNDERWATER MUNITIONS IN THE BALTIC SEA

2019 ◽  
Vol XLII-2/W10 ◽  
pp. 181-187 ◽  
Author(s):  
Y. Song ◽  
K. Köser ◽  
T. Kwasnitschka ◽  
R. Koch
Keyword(s):  
3D Reconstruction ◽  
Baltic Sea ◽  
Rapid Development ◽  
Depth Map ◽  
Ground Truth ◽  
Iterative Refinement ◽  
Underwater Imaging ◽  
The Baltic Sea ◽  
Dump Site ◽  
The Baltic

<p><strong>Abstract.</strong> With the rapid development and availability of underwater imaging technologies, underwater visual recording is widely used for a variety of tasks. However, quantitative imaging and photogrammetry in the underwater case has a lot of challenges (strong geometry distortion and radiometry issues) that limit the traditional photogrammetric workflow in underwater applications. This paper presents an iterative refinement approach to cope with refraction induced distortion while building on top of a standard photogrammetry pipeline. The approach uses approximate geometry to compensate for water refraction effects in images and then brings the new images into the next iteration of 3D reconstruction until the update of resulting depth maps becomes neglectable. Afterwards, the corrected depth map can also be used to compensate the attenuation effect in order to get a more realistic color for the 3D model. To verify the geometry improvement of the proposed approach, a set of images with air-water refraction effect were rendered from a ground truth model and the iterative refinement approach was applied to improve the 3D reconstruction. At the end, this paper also shows its application results for 3D reconstruction of a dump site for underwater munition in the Baltic Sea for which a visual monitoring approach is desired.</p>

scholarly journals Wind: generating power and cooling the power lines

2020 ◽  
Vol 17 ◽  
pp. 105-108
Author(s):  
Marko Kaasik ◽  
Sander Mirme
Keyword(s):  
Wind Speed ◽  
Electric Power ◽  
High Voltage ◽  
Transmission Lines ◽  
Power Transmission ◽  
Mixed Forest ◽  
Wind Farms ◽  
Power Line ◽  
Power Lines ◽  
Local Wind

Abstract. The electric power that can be transmitted via high-voltage transmission lines is limited by the Joule heating of the conductors. In the case of coastal wind farms, the wind that produces power simultaneously contributes to the cooling of high-voltage overhead conductors. Ideally this would allow for increased power transmission or decreased dimensions and cost of the conductor wires. In this study we investigate how well the wind speed in coastal wind farms is correlated with wind along a 75 km long 330 kW power line towards inland. It is found that correlations between wind speed in coastal wind farms at turbine height and conductor-level (10 m) are remarkably lower (R=0.39–0.64) than between wind farms at distances up to 100 km from each other (R=0.76–0.97). Dense mixed forest surrounding the power line reduces both local wind speed and the correlations with coastal higher-level wind, thus making the cooling effect less reliable.

scholarly journals Collision with power lines and electrocutions in birds — an analysis based on Swedish ringing recoveries 1990–2017

Ornis Svecica ◽  
2019 ◽  
Vol 29 ◽  
pp. 37-52
Author(s):  
Thord Fransson ◽  
Lina Jansson ◽  
Tuomo Kolehmainen ◽  
Thomas Wenninger
Keyword(s):  
At Risk ◽  
Natural History ◽  
Power Line ◽  
Power Lines ◽  
Local Power ◽  
Line System ◽  
Underground Cables ◽  
Number Of Species ◽  
History Information ◽  
Over Time

Recoveries of birds ringed in Sweden from the period 1990–2017 were used to analyse the occurrence of collisions with power lines and electrocutions. Out of more than 10,000 recoveries of birds found dead with finding circumstances mentioned, 8.6% was associated with power line constructions. The number of species involved was 51 and high proportions were especially evident in some species of owls and raptors. The overall proportion of recoveries caused by collision / electrocution shows a significant decrease over time. A decrease over time in the proportions of electrocution and collision was also evident when analysing finding circumstances in four species where corpses were sent to the Swedish Museum of Natural History. Information about the power line system in Sweden during the period 2007–2016 shows that the length of local power lines has decreased with about 21% during a ten-year period and that underground cables have increased with 28% during the same period. The results show that collisions with power lines have decreased more than electrocutions and this may imply that there are still many places where birds are at risk of being electrocuted.

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