Signal Processing in Settlement and Seepage Monitoring for Earth Levee Using Fully Distributed Sensing along Optical Fibers

2010 ◽  
Vol 36 ◽  
pp. 75-79 ◽  
Author(s):  
Ping Yu Zhu ◽  
Hong Yan Zeng ◽  
Yuan Bao Leng ◽  
Ji Ming Ma

In this study we analyze the signal in measurement system with distributed optical fiber sensors. The display signal is defined by the user not for general custom. The data of for-processing-part are processed regularly, which directly provides results for the user from the monitoring system. These results go into the next step to add environmental parameters, which includes weather, special events and season information. Information fusion and matching operation of the result and environment information enhances the accuracy of hidden hazard early warning.

2011 ◽  
Vol 103 ◽  
pp. 327-331
Author(s):  
Ping Yu Zhu ◽  
Hua Lei ◽  
Yuan Bao Leng

A monitoring structure has been designed to detect settlement using a tube with distributed optical fiber sensors inside. The strain of the optical fibers inside the detecting tube was calculated to estimate the settlement degree of earth dam. The Finite Element Method (FEM) analysis of the tube interaction with the earth dam by ANSYS software is applied to find the best installation location of the detecting tube.


2013 ◽  
Vol 543 ◽  
pp. 302-305
Author(s):  
Daniele Tosi ◽  
Massimo Olivero ◽  
Alberto Vallan ◽  
Guido Perrone

The paper analyzes the feasibility of cost-effective fiber sensors for the measurement of small vibrations, from low to medium-high frequencies, in which the complexity of the measurement is moved from expensive optics to cheap electronics without losing too much performance thanks to signal processing algorithms. Two optical approaches are considered: Bragg gratings in standard telecom fibers, which represent the most common type of commercial fiber sensors, and specifically developed sensors made with plastic optical fibers. In both cases, to keep the overall cost low, vibrations are converted into variations of the light intensity, although this makes the received signal more sensitive to noise. Then, adaptive filters and advanced spectral estimation techniques are used to mitigate noise and improve the sensitivity. Preliminary results have demonstrated that the combined effect of these techniques can yield to a signal-to-noise improvement of about 30 dB, bringing the proposed approaches to the level of the most performing sensors for the measurement of vibrations.


Sensors ◽  
2021 ◽  
Vol 21 (5) ◽  
pp. 1818
Author(s):  
Mattia Francesco Bado ◽  
Joan R. Casas

The present work is a comprehensive collection of recently published research articles on Structural Health Monitoring (SHM) campaigns performed by means of Distributed Optical Fiber Sensors (DOFS). The latter are cutting-edge strain, temperature and vibration monitoring tools with a large potential pool, namely their minimal intrusiveness, accuracy, ease of deployment and more. Its most state-of-the-art feature, though, is the ability to perform measurements with very small spatial resolutions (as small as 0.63 mm). This review article intends to introduce, inform and advise the readers on various DOFS deployment methodologies for the assessment of the residual ability of a structure to continue serving its intended purpose. By collecting in a single place these recent efforts, advancements and findings, the authors intend to contribute to the goal of collective growth towards an efficient SHM. The current work is structured in a manner that allows for the single consultation of any specific DOFS application field, i.e., laboratory experimentation, the built environment (bridges, buildings, roads, etc.), geotechnical constructions, tunnels, pipelines and wind turbines. Beforehand, a brief section was constructed around the recent progress on the study of the strain transfer mechanisms occurring in the multi-layered sensing system inherent to any DOFS deployment (different kinds of fiber claddings, coatings and bonding adhesives). Finally, a section is also dedicated to ideas and concepts for those novel DOFS applications which may very well represent the future of SHM.


2016 ◽  
Vol 28 (21) ◽  
pp. 2367-2370 ◽  
Author(s):  
Yifei Yu ◽  
Linqing Luo ◽  
Bo Li ◽  
Kenichi Soga ◽  
Jize Yan

2021 ◽  
Author(s):  
R. A. Perez-Herrera ◽  
M. Bravo ◽  
P. Roldan-Varona ◽  
D. Leandro ◽  
L. Rodriguez Cobo ◽  
...  

Author(s):  
Paolo Pennacchi ◽  
Gabriele Cazzulani ◽  
Alejandro Silva

Abstract This paper investigates the possibility of identifying and monitoring the modal shapes of a turbine blade by means of continuous optical fiber sensors based on Optical Backscatter Reflectometry (OBR). The advantage of this approach would be the possibility of embedding the sensors in future carbon fiber blades, in order to make this modal analysis approach available also for the blade operating conditions, since no modifications in the blade fluid-structure interaction occur. The paper describes the proposed method and provides some experimental results obtained on a 3D printed model of an existing steam turbine blade.


Sensors ◽  
2020 ◽  
Vol 20 (7) ◽  
pp. 2046 ◽  
Author(s):  
Stephanie Hui Kit Yap ◽  
Kok Ken Chan ◽  
Swee Chuan Tjin ◽  
Ken-Tye Yong

Recently, carbon allotropes have received tremendous research interest and paved a new avenue for optical fiber sensing technology. Carbon allotropes exhibit unique sensing properties such as large surface to volume ratios, biocompatibility, and they can serve as molecule enrichers. Meanwhile, optical fibers possess a high degree of surface modification versatility that enables the incorporation of carbon allotropes as the functional coating for a wide range of detection tasks. Moreover, the combination of carbon allotropes and optical fibers also yields high sensitivity and specificity to monitor target molecules in the vicinity of the nanocoating surface. In this review, the development of carbon allotropes-based optical fiber sensors is studied. The first section provides an overview of four different types of carbon allotropes, including carbon nanotubes, carbon dots, graphene, and nanodiamonds. The second section discusses the synthesis approaches used to prepare these carbon allotropes, followed by some deposition techniques to functionalize the surface of the optical fiber, and the associated sensing mechanisms. Numerous applications that have benefitted from carbon allotrope-based optical fiber sensors such as temperature, strain, volatile organic compounds and biosensing applications are reviewed and summarized. Finally, a concluding section highlighting the technological deficiencies, challenges, and suggestions to overcome them is presented.


Sign in / Sign up

Export Citation Format

Share Document