scholarly journals Structural analysis of clastic dikes based on Structure from Motion/Multi-View Stereo

2018 ◽  
Author(s):  
Carlos H Grohmann ◽  
Camila D Viana ◽  
Mariana TS Busarello ◽  
Guilherme PB Garcia
Keyword(s):  
Structural Analysis ◽  
Structure From Motion ◽  
Low Cost ◽  
Three Dimensional ◽  
Fine Sand ◽  
Bundle Adjustment ◽  
Three Dimensional Model ◽  
Focal Distance ◽  
Camera Orientation ◽  
Camera Position

This work presents the development of a three-dimensional model of an outcrop of the Corumbataí Formation using Structure from Motion and Multi-View Stereo (SfM-MVS) techniques in order to provide a structural analysis of clastic dikes cutting through siltstone layers. Composed mainly of fine sand and silt, these dikes are formed by sand intrusions when a wet sandy layer is affected by earthquakes of at least 6.5 magnitude, being used as a record of such events.While traditional photogrammetry requires the user to input a series of parameters related to the camera orientation and its characteristics (such as focal distance), in SfM-MVS the scene geometry, camera position and orientations are automatically determined by a bundle adjustment, an iterative procedure based on a set of overlapping images. It is considered a low-cost technique in both hardware and software, also being able to provide point density and accuracy on par to the ones obtained with terrestrial laser scanner.The results acquired on this research have a good agreement with previous works, yielding a NNW main orientation for the dikes measured in the field and on the 3D model. The development of this work showed that SfM-MVS use and practice on geosciences still needs more studies on the optimization of the involved parameters (such as camera orientation, image overlap and angle of illumination), which, when accomplished, will result in less processing time and more accurate models.

scholarly journals Structural analysis of clastic dikes based on Structure from Motion/Multi-View Stereo

2018 ◽  
Author(s):  
Carlos H Grohmann ◽  
Camila D Viana ◽  
Mariana TS Busarello ◽  
Guilherme PB Garcia
Keyword(s):  
Structural Analysis ◽  
Structure From Motion ◽  
Low Cost ◽  
Three Dimensional ◽  
Fine Sand ◽  
Bundle Adjustment ◽  
Three Dimensional Model ◽  
Focal Distance ◽  
Camera Orientation ◽  
Camera Position

This work presents the development of a three-dimensional model of an outcrop of the Corumbataí Formation using Structure from Motion and Multi-View Stereo (SfM-MVS) techniques in order to provide a structural analysis of clastic dikes cutting through siltstone layers. Composed mainly of fine sand and silt, these dikes are formed by sand intrusions when a wet sandy layer is affected by earthquakes of at least 6.5 magnitude, being used as a record of such events.While traditional photogrammetry requires the user to input a series of parameters related to the camera orientation and its characteristics (such as focal distance), in SfM-MVS the scene geometry, camera position and orientations are automatically determined by a bundle adjustment, an iterative procedure based on a set of overlapping images. It is considered a low-cost technique in both hardware and software, also being able to provide point density and accuracy on par to the ones obtained with terrestrial laser scanner.The results acquired on this research have a good agreement with previous works, yielding a NNW main orientation for the dikes measured in the field and on the 3D model. The development of this work showed that SfM-MVS use and practice on geosciences still needs more studies on the optimization of the involved parameters (such as camera orientation, image overlap and angle of illumination), which, when accomplished, will result in less processing time and more accurate models.

scholarly journals UAVs for Structure-From-Motion Coastal Monitoring: A Case Study to Assess the Evolution of Embryo Dunes over a Two-Year Time Frame in the Po River Delta, Italy

Sensors ◽  
2019 ◽  
Vol 19 (7) ◽  
pp. 1717 ◽  
Author(s):  
Yuri Taddia ◽  
Corinne Corbau ◽  
Elena Zambello ◽  
Alberto Pellegrinelli
Keyword(s):  
Cross Sections ◽  
Structure From Motion ◽  
Accuracy Assessment ◽  
Low Cost ◽  
Three Dimensional ◽  
Time Frame ◽  
Three Dimensional Model ◽  
Dune System ◽  
Po River ◽  
Time Saving

Coastal environments are usually characterized by a brittle balance, especially in terms of sediment transportation. The formation of dunes, as well as their sudden destruction as a result of violent storms, affects this balance in a significant way. Moreover, the growth of vegetation on the top of the dunes strongly influences the consequent growth of the dunes themselves. This work presents the results obtained through a long-term monitoring of a complex dune system by the use of Unmanned Aerial Vehicles (UAVs). Six different surveys were carried out between November 2015 and December 2017 in the littoral of Rosolina Mare (Italy). Aerial photogrammetric data were acquired during flight repetitions by using a DJI Phantom 3 Professional with the camera in a nadiral arrangement. The processing of the captured images consisted of the reconstruction of a three-dimensional model using the Structure-from-Motion (SfM). Each model was framed in the European Terrestrial Reference System (ETRS) using GNSS geodetic receivers in Network Real Time Kinematic (NRTK). Specific data management was necessary due to the vegetation by filtering the dense cloud. This task was performed by both performing a slope detection and a removal of the residual outliers. The final products of this approach were thus represented by Digital Elevation Models (DEMs) of the sandy coastal section. In addition, DEMs of Difference (DoD) were also computed for the purpose of monitoring over time and detecting variations. The accuracy assessment of the DEMs was carried out by an elevation comparison through especially GNSS-surveyed points. Relevant cross sections were also extracted and compared. The use of the Structure-from-Motion approach by UAVs finally proved to be both reliable and time-saving thanks to quicker in situ operations for the data acquisition and an accurate reconstruction of high-resolution elevation models. The low cost of the system and its flexibility represent additional strengths, making this technique highly competitive with traditional ones.

scholarly journals 3D MODELING OF ROMAN BRIDGE BY THE INTEGRATION OF TERRESTRIAL AND UAV PHOTOGRAMMETRIC SURVEY FOR STRUCTURAL ANALYSIS PURPOSE

2019 ◽  
Vol XLII-2/W17 ◽  
pp. 249-255 ◽  
Author(s):  
M. Pepe ◽  
D. Costantino ◽  
N. Crocetto ◽  
A. Restuccia Garofalo
Keyword(s):  
Structural Analysis ◽  
3D Model ◽  
Low Cost ◽  
Three Dimensional ◽  
Digital Cameras ◽  
Three Dimensional Model ◽  
Aerial Surveys ◽  
Special Procedure ◽  
Photogrammetric Method ◽  
Three Dimensional Models

Abstract. The 3D survey of the masonry bridges is rather complex and may require the integration of terrestrial and aerial surveys. In fact, in order to perform the survey of the superstructure of a bridge, the photogrammetric survey may be realized by the use UAV (Unmanned Aerial Vehicle) since it allows acquiring all the details of the upper part of the bridge. Indeed, especially the extreme lateral parts of the bridge cannot be performed through a traditional terrestrial survey. In addition, the UAV photogrammetry allows speeding up and optimizing work. As regards the terrestrial survey, instead, it has the advantage of being able to use highly performing optics and cameras (high resolution of the sensor, stabilized optics, etc.). However, these types of sensors are quite heavy and, in general, could not be mounted on an aerial platform on commercial and low-cost drones. In any case, beyond the payload of common commercial drones at low cost, there is also the problem that the digital cameras mounted on the UAV platforms cannot observe the arches of the bridge from the bottom upwards by low-cost tools. Therefore, a simple way to build a unique 3D model consists in the integration of terrestrial and aerial surveys; in this way, using a suitable procedure, sensor and software based on the Structure from Motion (SfM) and Multi View Stereo (MVS) approaches, it was possible to build detailed, precise and textured three-dimensional models of structures, such as the buildings, historical artefact, bridges etc.In this paper, a case study concerning the construction of a three-dimensional model according a photogrammetric method of a Roman bridge is discussed. In particular, the bridge taken under investigation, belong to the Cultural Heritage, is called “San Cono” and is located in south of Italy. After built the 3D model of masonry bridge (3D point cloud and 3D mesh), it was identified a special procedure that allowed to obtain the model of the bridge suitable for a structural analysis within of dedicate software.

Design and operation of a tripod walking robot via dynamics simulation

Robotica ◽  
2010 ◽  
Vol 29 (5) ◽  
pp. 733-743 ◽  
Author(s):  
Conghui Liang ◽  
Hao Gu ◽  
Marco Ceccarelli ◽  
Giuseppe Carbone
Keyword(s):  
Mechanical Design ◽  
Low Cost ◽  
Three Dimensional ◽  
The Body ◽  
Dynamics Simulation ◽  
Walking Ability ◽  
Walking Robot ◽  
Three Dimensional Model ◽  
Software Environment ◽  
Leg Mechanisms

SUMMARYA mechanical design and dynamics walking simulation of a novel tripod walking robot are presented in this paper. The tripod walking robot consists of three 1-degree-of-freedom (DOF) Chebyshev–Pantograph leg mechanisms with linkage architecture. A balancing mechanism is mounted on the body of the tripod walking robot to adjust its center of gravity (COG) during walking for balancing purpose. A statically stable tripod walking gait is performed by synchronizing the motions of the three leg mechanisms and the balancing mechanism. A three-dimensional model has been elaborated in SolidWorks® engineering software environment for a characterization of a feasible mechanical design. Dynamics simulation has been carried out in the MSC.ADAMS® environment with the aim to characterize and to evaluate the dynamic walking performances of the proposed design with low-cost easy-operation features. Simulation results show that the proposed tripod walking robot with proper input torques, gives limited reaction forces at the linkage joints, and a practical feasible walking ability on a flatten ground.

scholarly journals IMPROVING UAV TELEMETRY POSITIONING FOR DIRECT PHOTOGRAMMETRY

2021 ◽  
Vol XLIII-B2-2021 ◽  
pp. 61-68
Author(s):  
L. Rossi ◽  
F. Ioli ◽  
E. Capizzi ◽  
L. Pinto ◽  
M. Reguzzoni
Keyword(s):  
Low Cost ◽  
Three Dimensional ◽  
Control Points ◽  
Three Dimensional Model ◽  
Commercial Software ◽  
Ground Control Points ◽  
Lower Accuracy ◽  
Least Squares Adjustment ◽  
Gnss Receivers

Abstract. A fundamental step of UAV photogrammetric processes is to collect Ground Control Points (GCPs) by means of geodetic-quality GNSS receivers or total stations, thus obtaining an absolutely oriented model with a centimetric accuracy. This procedure is usually time-consuming, expensive and potentially dangerous for operators who sometimes need to reach inaccessible areas. UAVs equipped with low-cost GNSS/IMU sensors can provide information about position and attitude of the images. This telemetry information is not enough for a photogrammetric restitution with a centimetric accuracy, but it can be usefully exploited when a lower accuracy is required. The algorithm proposed in this paper aims at improving the quality of this information, in order to introduce it into a direct-photogrammetric process, without collecting GCPs. In particular, the estimation of an optimal trajectory is obtained by combining the camera positions derived from UAV telemetry and from the relative orientation of the acquired images, by means of a least squares adjustment. Then, the resulting trajectory is used as a direct observation of the camera positions into a commercial software, thus replacing the information of GCPs. The algorithm has been tested on different datasets, comparing the classical photogrammetric solution (with GCPs) with the proposed one. These case-studies showed that using the improved trajectory as input to the commercial software (without GCPs) the reconstruction of the three-dimensional model can be improved with respect to the solution computed by using the UAV raw telemetry only.

Stable Platform Based on Workbench Vehicle Structure Analysis

2013 ◽  
Vol 477-478 ◽  
pp. 132-134
Author(s):  
Jin Xia Liu ◽  
Chong Chen ◽  
Liang Wang ◽  
Cong Zhang
Keyword(s):  
Numerical Analysis ◽  
Structural Analysis ◽  
Structure Analysis ◽  
Tilt Angle ◽  
Three Dimensional ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
Vehicle Structure ◽  
Platform Tilt

This paper has conducted a structural analysis by workbench after establishing a stable platform for automotive three-dimensional model, primarily concerning whether the platform can provide a benchmark to meet the requirements of equipment, including the numerical analysis of whether the platform tilt angle under load can achieve the requirements as well as the scheme of improvement direction of the structure.

Design of Bilateral Automatic Window Cleaning Device Based on Solid Edge

2014 ◽  
Vol 662 ◽  
pp. 183-186
Author(s):  
Guo Lei Xu ◽  
Tao Wu
Keyword(s):  
Simple Structure ◽  
High Efficiency ◽  
Simulation Analysis ◽  
Low Cost ◽  
Three Dimensional ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
Model And Simulation ◽  
Cleaning Device ◽  
Solid Edge

This paper introduces an easy-sided automatic window cleaning device, which uses Solid Edge software to design three-dimensional model and simulation analysis of the structure. Contrasted with the function of existing products, this design has such advantages as simple structure, low cost, high efficiency, good effects and so on.

scholarly journals Modelling and Visualization of Three Dimensional Objects Using Inexpensive Digital Cameras

2018 ◽  
Author(s):  
Ismail Elkhrachy
Keyword(s):  
Low Cost ◽  
Three Dimensional ◽  
Point Clouds ◽  
3D Models ◽  
Bundle Adjustment ◽  
Control Points ◽  
Digital Cameras ◽  
Three Dimensional Objects ◽  
Spatial Positioning ◽  
And Control

This paper analyses and evaluate the precision and the accuracy the capability of low-cost terrestrial photogrammetry by using many digital cameras to construct a 3D model of an object. To obtain the goal, a building façade has imaged by two inexpensive digital cameras such as Canon and Pentax camera. Bundle adjustment and image processing calculated by using Agisoft PhotScan software. Several factors will be included during this study, different cameras, and control points. Many photogrammetric point clouds will be generated. Their accuracy will be compared with some natural control points which collected by the laser total station of the same building. The cloud to cloud distance will be computed for different comparison 3D models to investigate different variables. The practical field experiment showed a spatial positioning reported by the investigated technique was between 2-4cm in the 3D coordinates of a façade. This accuracy is optimistic since the captured images were processed without any control points.

scholarly journals Geohazards Affecting Cultural Heritage Monuments. A Complex Case Study From Romania

2020 ◽  
Author(s):  
Dorina Camelia Ilies ◽  
Tudor Caciora ◽  
Grigore Vasile Herman ◽  
Alexandru Ilies ◽  
Madalina Ropa ◽  
...  
Keyword(s):  
Cultural Heritage ◽  
Low Cost ◽  
Three Dimensional ◽  
Field Research ◽  
Complex Case ◽  
Three Dimensional Model ◽  
Main Research ◽  
Object A ◽  
Extensive Field ◽  
The Impact

Abstract The impact that geohazards have on cultural heritage requires continuous research in order to assess risks, prevention and conservation. This study has as the main research object, a uniquen monument in terms of its connection with the risk phenomena. It is about a wooden church historical monument from the village of Corbești, Romania, which was destroyed at the beginning of the tenth decade of the last century by a meteorological hazard, later reconstructed on a new site (in Oradea Municipality), and currently there is a risk of being affected by a geological hazard. The study focused on three main directions of research, namely: reconstructing the film of events, analyzing current risks and finding viable methods for future conservation and promotion. The methodology is based on extensive field research and the use of digital technologies. The results obtained confirmed the church's tendency to be affected by the emergence of a new risk phenomenon - landslides. In order to conserve and rebuild in case of need, the monument was digitized and a three-dimensional model of high accuracy was developed. This approach has the advantage of being low-cost, fast, non-invasive and providing large volumes of valuable information in the process of cultural heritage conservation.

Research on Intangible Cultural Heritage Based on Motion Capture

2014 ◽  
Vol 568-570 ◽  
pp. 676-680
Author(s):  
Si Xi Chen ◽  
Shu Chen
Keyword(s):  
Cultural Heritage ◽  
Motion Capture ◽  
Low Cost ◽  
Three Dimensional ◽  
Intangible Cultural Heritage ◽  
Three Dimensional Model ◽  
Motion Data ◽  
Optical Motion ◽  
Capture Method ◽  
Optical Motion Capture

The application of digital technology on the protection of intangible cultural heritage is a major topic of research in recent years. The motion capture technology of protection will gradually replace the traditional recording methods such as texts, pictures and videos. It is valuable to build a high-fidelity, high-modular and low-cost digital platform for choreographic data collection and extended application. This paper studies the intangible cultural heritage of Quanzhou breast-clapping dance, one of the most famous choreographic intangible cultural heritages from China with standard optical motion capture method. The data are acquiring and processing after the dance motion capture, we binds the motion data and three-dimensional model using Motion Builder and build digital demonstration platform base on an OGRE engine to display the movements. The viewer can view at any angle and distance. The system can be easily applied in motion intangible cultural heritages protection project. Furthermore, the system can be provided versatile motion data for additional use.

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