The Application and Comparison of Digital Ground Photogrammetry Technology for Bridge Safety Monitoring

2012 ◽  
Vol 170-173 ◽  
pp. 2979-2986
Author(s):  
Ming Zhi Chen
Keyword(s):  
System Reliability ◽  
Civil Engineering ◽  
Dynamic Deformation ◽  
Large Data ◽  
Safety Monitoring ◽  
Digital Cameras ◽  
Bridge Safety ◽  
Laser Scanners ◽  
Close Range ◽  
Strong System

For needs of transportation, it is more and more obvious of the bridge unsafe, and the study of bridge safety monitor will become more important at the area of civil engineering. In this paper we discuss the methods of digital ground photogrammetry for bridge safety monitoring and the application of those, we took digital cameras and 3-D laser scanners as the tools for close-range photogrammetry, and adopted 3D Time Baseline Parallax combined with Kalman Variance Filters as the theories for monitoring dynamic deformation, then developed software to deal with data, which can draw curves of dynamic deformation automatically, we can monitor the deformation regularity by these curves effectively, then we can monitor and analysis the safety of bridges by this way. The method we designed is very simple and economical, and we also did a lot of experiments to verify availability of this system, and we happy to say that the system has the characteristics of high automation degree, large data collection capacity and strong system reliability, etc. It will be practical value at the area of civil engineering.

scholarly journals Structure from Motion Point Clouds for Structural Monitoring

2019 ◽  
Vol 11 (16) ◽  
pp. 1940 ◽  
Author(s):  
Fausto Mistretta ◽  
Giannina Sanna ◽  
Flavio Stochino ◽  
Giuseppina Vacca
Keyword(s):  
Structure From Motion ◽  
Point Clouds ◽  
Structural Deformation ◽  
Beam Loading ◽  
Close Range Photogrammetry ◽  
Laser Scanners ◽  
Dense Point ◽  
Close Range ◽  
Bending Loading ◽  
Geometric Primitives

Dense point clouds acquired from Terrestrial Laser Scanners (TLS) have proved to be effective for structural deformation assessment. In the last decade, many researchers have defined methodology and workflow in order to compare different point clouds, with respect to each other or to a known model, assessing the potentialities and limits of this technique. Currently, dense point clouds can be obtained by Close-Range Photogrammetry (CRP) based on a Structure from Motion (SfM) algorithm. This work reports on a comparison between the TLS technique and the Close-Range Photogrammetry using the Structure from Motion algorithm. The analysis of two Reinforced Concrete (RC) beams tested under four-points bending loading is presented. In order to measure displacement distributions, point clouds at different beam loading states were acquired and compared. A description of the instrumentation used and the experimental environment, along with a comprehensive report on the calculations and results obtained is reported. Two kinds of point clouds comparison were investigated: Mesh to mesh and modeling with geometric primitives. The comparison between the mesh to mesh (m2m) approach and the modeling (m) one showed that the latter leads to significantly better results for both TLS and CRP. The results obtained with the TLS for both m2m and m methodologies present a Root Mean Square (RMS) levels below 1 mm, while the CRP method yields to an RMS level of a few millimeters for m2m, and of 1 mm for m.

On-Line Industrial 3D Measurement Techniques for Large Volume Objects

2005 ◽  
Vol 295-296 ◽  
pp. 423-430 ◽  
Author(s):  
Ji Gui Zhu ◽  
S.H. Ye ◽  
Xue You Yang ◽  
Xing Hua Qu ◽  
C.J. Liu ◽  
...  
Keyword(s):  
Large Volume ◽  
Measurement Techniques ◽  
Integrated System ◽  
3D Measurement ◽  
Digital Cameras ◽  
Combined Use ◽  
Small Set ◽  
Close Range ◽  
On Line ◽  
Set Up

Rapid progress in modern manufacturing demands for better measurement technique with on-line characteristics. This paper presents a systematic visual solution for on-line industrial 3D measurement. The solution comprises two parts, a multi-sensor visual inspecting station (MSVIS) and a digital close-range visual inspecting station (DCVIS). MSVIS is an integrated system with many sensors. It can meet the requirement of application with sparse measuring points distributed within a large volume. DCVIS only contains two digital cameras with one or more projectors. It has high relative accuracy and a small set up volume and is suitable for applications with dense measuring points. The combined use of MSVIS and DCVIS can provide a general solution for on-line industrial 3D measurement.

scholarly journals Photogrammetric survey of dinosaur skeletons

Fossil Record ◽  
1999 ◽  
Vol 2 (1) ◽  
pp. 113-119 ◽  
Author(s):  
A. Wiedemann ◽  
T. Suthau ◽  
J. Albertz
Keyword(s):  
Data Acquisition ◽  
Surface Area ◽  
Reference System ◽  
Physiological Data ◽  
Control Network ◽  
Detailed Survey ◽  
Laser Scanners ◽  
Stereo Photogrammetry ◽  
Close Range

Abstract. To derive physiological data of dinosaurs, it is necessary to determine the volume and the surface area of this animals. For this purpose, a detailed survey of reconstructed skeletons is required. The skeletons of three dinosaurs in the Museum für Naturkunde in Berlin and two skeletons in the Museum d'Histoire Naturelle in Paris have been surveyed using stereo photogrammetry. Two of the Berlin skeletons were also surveyed with the close range laser scanners of the Institut für Navigation of the Universität Stuttgart. Both data acquisition techniques require a geodetic control network as a geometric reference system. The surveying methods used, together with results of mathematical approaches for the determination of the volume and surface of the animals are presented in this paper. Zur Herleitung physiologischer Daten der Dinosaurier ist es erforderlich, zunächst Volumen und Oberfläche ihres Körpers zu bestimmen. Dazu wurde eine detaillierte Vermessung rekonstruierter Skelette durchgeführt. Die Skelette dreier Saurier im Museum für Naturkunde in Berlin und zweier im Museum d'Histoire Naturelle in Paris wurden stereophotogrammetrisch vermessen. Bei zwei der Berliner Skelette wurden zusätzlich die Laserscanner des Instituts für Navigation der Universität Stuttgart eingesetzt. Beide Datenerfassungstechniken benötigen ein Paßpunktfeld als geometrisches Referenzsystem. Die verwendeten Vermessungsmethoden, die mathematischen Ansätze für die Berechnung von Volumina und Oberflächen und die Ergebnisse werden in diesem Aufsatz vorgestellt. doi:10.1002/mmng.1999.4860020108

Full-field dynamic deformation and strain measurements using high-speed digital cameras

2005 ◽  
Author(s):  
Timothy E. Schmidt ◽  
John Tyson ◽  
Konstantin Galanulis ◽  
Duane M. Revilock ◽  
Matthew E. Melis
Keyword(s):  
High Speed ◽  
Dynamic Deformation ◽  
Digital Cameras ◽  
Full Field ◽  
Strain Measurements ◽  
Field Dynamic

scholarly journals USING SMART PHONES FOR DEFORMATIONS MEASUREMENTS OF STRUCTURES

2017 ◽  
Vol 43 (2) ◽  
pp. 66-72 ◽  
Author(s):  
Khalid L. A. EL-ASHMAWY
Keyword(s):  
Least Squares ◽  
Smart Phones ◽  
Digital Cameras ◽  
Object Space ◽  
Close Range Photogrammetry ◽  
Variable Displacement ◽  
Close Range ◽  
Displacement Transducers ◽  
Better Than

The present work tests the suitability of using the digital cameras of smart phones for close range photogrammetry applications. For this purpose two cameras of smart phones Lumia 535 and Lumia 950 XL were used. The resolutions of the two cameras are 5 and 20 Mpixels respectively. The tests consist of (a) self calibration of the two cameras, (b) the implementation of close-range photogrammetry using the cameras of the two smart phones, theodolite intersection with LST method, and linear variable displacement transducers (LVDTs) for the measurement of vertical deflections, and (c) accuracy of photogrammetric determination of object space coordinates. The results of using Lumia 950 XL are much better than using Lumia 535 and are better or comparable to the results of theodolite intersection with least squares technique (LST). Finally, it can be stated that the digital cameras of smart phones are suitable for close range photogrammetry applications according to accuracy, costs and flexibility.

scholarly journals EXPERIMENTS ON CALIBRATING TILT-SHIFT LENSES FOR CLOSE-RANGE PHOTOGRAMMETRY

2016 ◽  
Vol XLI-B5 ◽  
pp. 99-105 ◽  
Author(s):  
E. Nocerino ◽  
F. Menna ◽  
F. Remondino ◽  
J.-A. Beraldin ◽  
L. Cournoyer ◽  
...  
Keyword(s):  
Optical Axis ◽  
National Research Council ◽  
Image Plane ◽  
Limiting Factors ◽  
Depth Of Field ◽  
Small Object ◽  
Digital Cameras ◽  
Close Range Photogrammetry ◽  
Object Distance ◽  
Close Range

One of the strongest limiting factors in close range photogrammetry (CRP) is the depth of field (DOF), especially at very small object distance. When using standard digital cameras and lens, for a specific camera – lens combination, the only way to control the extent of the zone of sharp focus in object space is to reduce the aperture of the lens. However, this strategy is often not sufficient; moreover, in many cases it is not fully advisable. In fact, when the aperture is closed down, images lose sharpness because of diffraction. Furthermore, the exposure time must be lowered (susceptibility to vibrations) and the ISO increased (electronic noise may increase). In order to adapt the shape of the DOF to the subject of interest, the Scheimpflug rule is to be applied, requiring that the optical axis must be no longer perpendicular to the image plane. Nowadays, specific lenses exist that allow inclining the optical axis to modify the DOF: they are called tilt-shift lenses. In this paper, an investigation on the applicability of the classic photogrammetric model (pinhole camera coupled with Brown’s distortion model) to these lenses is presented. Tests were carried out in an environmentally controlled metrology laboratory at the National Research Council (NRC) Canada and the results are hereafter described in detail.

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