Investigation on Temperature Compensation of Fiber Bragg Grating Sensors for Hull Monitoring

Hull monitoring system with Fiber Bragg Grating (FBG) sensors increasingly receives people’s attentions. However, for the ship hull monitoring, the deformation of hull girder changes a lot as is subjected to a huge temperature variation. Therefore, the compensation method with only FBG temperature self-correction is not suitable for the hull monitoring sensors because no material thermal expansion effects are reasonably included. In this paper, the new compensation method of hull monitoring FBG sensor based on the sensor theory with both FBG temperature self-correction and steel thermal expansion effects correction is studied. The coupled compensation method suitable for hull monitoring sensor is obtained by theoretical derivation. As the comparison, the coupled compensation experiment was carried out. The results show that the relative error under the temperature compensation method is large in the case of drastic strain and temperature changes, and the correction results of the tested method will be closer to the true level.

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Research on a Fiber Bragg Grating Strain Sensor for Tower Vibration

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.496-500.1373 ◽

2014 ◽

Vol 496-500 ◽

pp. 1373-1375

Author(s):

Jin Feng Geng ◽

Hong Sheng Cai ◽

Yong Tao Wei ◽

Xiao Huan Shen ◽

Jun Wei Dong

Keyword(s):

Fiber Bragg Grating ◽

Temperature Compensation ◽

Strain Sensor ◽

Compensation Method ◽

Bragg Grating ◽

Encapsulation Process ◽

Tower Vibration

In order to monitor the key parts strain of tower vibration, design a fiber Bragg grating strain sensor, and introduce its structure, encapsulation process and temperature compensation method.

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Detection of Pipeline Curvature with FBG Sensors Twisted

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.303-306.67 ◽

2013 ◽

Vol 303-306 ◽

pp. 67-73 ◽

Cited By ~ 2

Author(s):

Yan An Zhang ◽

Zheng Liu ◽

Lin Yong Shen ◽

Jin Wu Qian

Keyword(s):

Fiber Bragg Grating ◽

Curve Fitting ◽

Bragg Grating ◽

Bending Deformation ◽

Fbg Sensor ◽

Underground Pipelines ◽

Fbg Sensors ◽

Simulation Results ◽

Spatial Trajectory ◽

Fitting Accuracy

In trenchless detection of underground pipelines, a method has been introduced which employs Fiber Bragg Grating (FBG) sensors to detect curvatures of the pipeline at discrete points and reconstructs the spatial trajectory of the pipeline by means of a newly developed approach. In measuring the pipeline curvature, the FBG sensor may be twisted besides sustaining bending deformation. This paper proposes a new algorithm for curvature calculation at discrete points, considering both overall revolving and partial twisting of the FBG sensors in order to enhance the curve fitting accuracy. Simulation results verify the effectiveness of the method.

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Cladding Modified Fiber Bragg Grating for Copper Ions Detection

Semiconductor Science and Information Devices ◽

10.30564/ssid.v3i2.3749 ◽

2021 ◽

Vol 3 (2) ◽

Author(s):

Husam Abduldaem Mohammed ◽

Aqiel Almamori ◽

Ali A. Alwahib

Keyword(s):

Fiber Bragg Grating ◽

Copper Ions ◽

Evanescent Field ◽

Bragg Grating ◽

Wavelength Shift ◽

Chemical Agent ◽

Toxic Heavy Metal ◽

Fbg Sensor ◽

Fbg Sensors ◽

Significant Wavelength

This paper reports a fiber Bragg grating (FBG) as a biosensor. The FBGs were etched using a chemical agent,namely,hydrofluoric acid (HF). This implies the removal of some part of the cladding layer. Consequently, the evanescent field propagating out of the core will be closer to the environment and become more sensitive to the change in the surrounding. The proposed FBG sensor was utilized to detect toxic heavy metal ions aqueous medium namely, copper ions (Cu2+). Two FBG sensors were etched with 20 and 40 μm diameters and fabricated. The sensors were studied towards Cu2+ with different concentrations using wavelength shift as a result of the interaction between the evanescent field and copper ions. The FBG sensors showed a good response in terms of significant wavelength shift in corresponding to varying Cu2+ concentrations when immersed in aqueous mediums. The sensors exhibited excellent repeatability towards Cu ions.The results demonstrate that the smaller FBG etching diameter, the better optical response in terms of wavelength and linearity.

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Real Time Monitoring of Railway Traffic Using Fiber Bragg Grating Sensors

2010 Joint Rail Conference, Volume 2 ◽

10.1115/jrc2010-36211 ◽

2010 ◽

Cited By ~ 6

Author(s):

M. L. Filograno ◽

A. Rodri´guez-Barrios ◽

M. Gonza´lez-Herraez ◽

P. Corredera ◽

S. Marti´n-Lo´pez ◽

...

Keyword(s):

Fiber Bragg Grating ◽

High Speed ◽

Field Tests ◽

Bragg Grating ◽

Railway Traffic ◽

Fbg Sensor ◽

Commercial Operation ◽

Load Calculation ◽

Different Types ◽

Fbg Sensors

In this work we present field tests concerning the application of Fiber Bragg Grating (FBG) sensors for the monitoring of railway traffic. The test campaigns are performed on the Spanish high speed line Madrid–Barcelona, with different types of trains (S-102 TALGO–BOMBARDIER, S-103 SIEMENS-VELARO and S-120 CAF). We located the FBG sensors in the rail track at 70 km from Madrid in the country side, where the trains primarily are tested during commercial operation with maximum speeds between 250–300 km/h. The FBG sensor interrogation system used allows the simultaneous monitoring of four FBG sensors at 8000 samples/s. The different position of the FBG sensors in relation with the rail can be used with different purposes such as train identification, axle counting, speed and acceleration detection, wheel imperfections monitoring and dynamic load calculation.

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Cantilever Beam with a Single Fiber Bragg Grating to Measure Temperature and Transversal Force Simultaneously

Sensors ◽

10.3390/s21062002 ◽

2021 ◽

Vol 21 (6) ◽

pp. 2002

Author(s):

Abdulfatah A. G. Abushagur ◽

Norhana Arsad ◽

Ahmad Ashrif A. Bakar

Keyword(s):

Fiber Bragg Grating ◽

Bragg Grating ◽

Calibration System ◽

Temperature Variations ◽

Temperature Changes ◽

Fbg Sensor ◽

The Matrix ◽

Transversal Force ◽

Future Work ◽

Calibration Coefficients

This work investigates a new interrogation method of a fiber Bragg grating (FBG) sensor based on longer and shorter wavelengths to distinguish between transversal forces and temperature variations. Calibration experiments were carried out to examine the sensor’s repeatability in response to the transversal forces and temperature changes. An automated calibration system was developed for the sensor’s characterization, calibration, and repeatability testing. Experimental results showed that the FBG sensor can provide sensor repeatability of 13.21 pm and 17.015 pm for longer and shorter wavelengths, respectively. The obtained calibration coefficients expressed in the linear model using the matrix enabled the sensor to provide accurate predictions for both measurements. Analysis of the calibration and experiment results implied improvements for future work. Overall, the new interrogation method demonstrated the potential to employ the FBG sensing technique where discrimination between two/three measurands is needed.

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Design Reliable Bus Structure Distributed Fiber Bragg Grating Sensor Network Using Gated Recurrent Unit Network

Sensors ◽

10.3390/s20247355 ◽

2020 ◽

Vol 20 (24) ◽

pp. 7355

Author(s):

Amare Mulatie Dehnaw ◽

Yibeltal Chanie Manie ◽

Ya Yu Chen ◽

Po Han Chiu ◽

Hung Wei Huang ◽

...

Keyword(s):

Sensor Networks ◽

Fiber Bragg Grating ◽

Wavelength Division Multiplexing ◽

Bragg Grating ◽

Bragg Wavelength ◽

Wavelength Division ◽

Fbg Sensor ◽

Bus Structure ◽

Fbg Sensors ◽

Gated Recurrent Unit

The focus of this paper was designing and demonstrating bus structure FBG sensor networks using intensity wavelength division multiplexing (IWDM) techniques and a gated recurrent unit (GRU) algorithm to increase the capability of multiplexing and the ability to detect Bragg wavelengths with greater accuracy. Several Fiber Bragg grating (FBG) sensors are coupled with power ratios of 90:10 and 80:10, respectively in the suggested experimental setup. We used the latest IWDM multiplexing technique for the proposed scheme, as the IWDM system increases the number of sensors and allows us to alleviate the limited operational region drawback of conventional wavelength division multiplexing (WDM). However, IWDM has a crosstalk problem that causes high-sensor signal measurement errors. Thus, we proposed the GRU model to overcome this crosstalk or overlapping problem by converting the spectral detection problem into a regression problem and considered the sequence of spectral features as input. By feeding this sequential spectrum dataset into the GRU model, we trained the GRU system until we achieved optimal efficiency. Consequently, the well-trained GRU model quickly and accurately identifies the Bragg wavelength of each FBG from the overlapping spectra. The Bragg wavelength detection performance of our proposed GRU model is tested or validated using different numbers of FBG sensors, such as 3-FBG, 5-FBG, 7-FBG, and 10-FBG, separately. As a result, the experiment result proves that the well-trained GRU model accurately identifies each FBG Bragg wavelength, and even the number of FBG sensors increase, as well as the spectra of FBGs, which are partially or fully overlapped. Therefore, to boost the detection efficiency, reliability, and to increase the multiplexing capabilities of FBG sensor networks, the proposed sensor system is better than the other previously proposed methods.

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Development of Sandglass Shape FBG Sensor to Reduce Cross Sensitivity Effect

International Journal of Optics ◽

10.1155/2013/636987 ◽

2013 ◽

Vol 2013 ◽

pp. 1-3 ◽

Cited By ~ 3

Author(s):

Bo Zhang

Keyword(s):

Temperature Measurement ◽

Fiber Bragg Grating ◽

Pressure Sensor ◽

Pressure Measurement ◽

Axial Strain ◽

Bragg Grating ◽

Cross Sensitivity ◽

Fbg Sensor ◽

Transverse Pressure ◽

Fbg Sensors

Fiber Bragg grating (FBG) sensors have received considerable attention in applications of temperature, axial strain, and transverse pressure measurement. However, the cross-sensitivity of strain and temperature measurement is the key problem of FBG sensors. In this paper, a sandglass shape FBG is proposed to divide cross-sensitivity of temperature and transverse pressure. The principle and structure of sandglass FBG are introduced, and the experiment results show cross-sensitivity avoidable in the transverse pressure sensor.

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Demonstration of a Filterless, Multi-Point, and Temperature-Independent Fiber Bragg Grating Dynamical Demodulator Using Pulse-Width Modulation

Sensors ◽

10.3390/s20205825 ◽

2020 ◽

Vol 20 (20) ◽

pp. 5825

Author(s):

Joao B. Rosolem ◽

Marcio C. Argentato ◽

Fábio R. Bassan ◽

Rivael S. Penze ◽

Claudio Floridia ◽

...

Keyword(s):

Fiber Bragg Grating ◽

Pulse Width ◽

Pulse Width Modulation ◽

Optical Filter ◽

Tunable Laser ◽

Harsh Environments ◽

Bragg Grating ◽

Wavelength Shift ◽

Fbg Sensor ◽

Fbg Sensors

We demonstrated in this work a filterless, multi-point and temperature-independent FBG (fiber Bragg grating) dynamical demodulator using pulse-width-modulation (PWM). In this approach, the FBG interrogation system is composed of a tunable laser and a demodulator that is designed to detect the wavelength shift of the FBG sensor without any optical filter making it very suitable to be used in harsh environments. In this work, we applied the proposed method that uses the PWM technique for FBG sensors placed in high pressure and high-temperature environments. The proposed method was characterized in the laboratory using an FBG sensor modulated in a frequency of 6 Hz, with a 1 kHz sweeping frequency in the wavelength range from 1527 to 1534 nm. Also, the method was evaluated in a field test in an engine of a thermoelectric power plant.

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Application of the Microclamped Fiber Bragg Grating (FBG) Sensor in Rock Bolt Support Quality Monitoring

Advances in Civil Engineering ◽

10.1155/2020/3419835 ◽

2020 ◽

Vol 2020 ◽

pp. 1-10 ◽

Cited By ~ 1

Author(s):

Xinxin Guo ◽

Bo Wang ◽

Zhenyu Wang ◽

Wei Yu ◽

Zhenwang Ma ◽

...

Keyword(s):

Fiber Bragg Grating ◽

Mechanical Performance ◽

Rock Bolt ◽

Theoretical Formula ◽

Bragg Grating ◽

Test Sensitivity ◽

Fbg Sensor ◽

Measured Strain ◽

Fbg Sensors ◽

Rock Bolt Support

The force-measuring rock bolt instrumented with bare fiber Bragg grating (FBG) sensors are generally factory-fabricated. To enable users to fabricate a force-measuring rock bolt by themselves, the microclamped FBG sensor is proposed to replace the encapsulated bare FBG sensor. A theoretical formula of strain sensitivity is also established. The strain sensibility measured by indoor calibration is consistent with the theoretical one, indicating that the microclamped FBG sensor can measure strain accurately. Besides, the measured strain sensibility coefficient (wavelength difference/strain) matches the theoretical values, making the installed microclamped sensor free from the need for recalibration and proving the installation method to be reliable. Also, the test sensitivity can be adjusted as needed. The instrumented rock bolt with microclamped FBG sensors shows great mechanical performance in the field test, awaiting further usage in applications.

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