Research on Fiber-Optic Strain Signal Processing Based on Demodulation Technique

2010 ◽  
Vol 44-47 ◽  
pp. 2569-2572 ◽  
Author(s):  
Xiao Wei Du ◽  
Li Rong Li

A higher performance signal processing module is demanded because of the high sensitivity of fiber-optic sensor probe. Excellent signal processing module is expected have the function of restore the sensor signal and very little to the introduction of noise. In this paper, improved demodulation algorithm is proposed based on the general demodulation algorithm through changing certain parameters of the algorithm aimed to improve the quality of the signal after demodulation. The output signals of scene sensor probe is sampling, sampling data through filtering. By using the improved fiber optic sensor signal demodulation algorithm, the system can fully improve the quality of the signal after demodulation under the premise of maintains the minimum sampling rate.

Author(s):  
Radek Martinek ◽  
Radana Kahankova ◽  
Jan Nedoma ◽  
Marcel Fajkus ◽  
Martin Novák ◽  
...  

Sensors ◽  
2012 ◽  
Vol 12 (8) ◽  
pp. 10906-10919 ◽  
Author(s):  
Tae-Sik Cho ◽  
Ki-Sun Choi ◽  
Dae-Cheol Seo ◽  
Il-Bum Kwon ◽  
Jung-Ryul Lee

Sensor Review ◽  
2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Adel Abdallah ◽  
Mohamed M. Fouad ◽  
Hesham N. Ahmed

Purpose The purpose of this paper is to introduce a novel intensity-modulated fiber optic sensor for real-time intrusion detection using a fiber-optic microbend sensor and an optical time-domain reflectometer (OTDR). Design/methodology/approach The proposed system is tested using different scenarios using person/car as intruders. Experiments are conducted in the lab and in the field. In the beginning, the OTDR trace is obtained and recorded as a reference signal without intrusion events. The second step is to capture the OTDR trace with intrusion events in one or multiple sectors. This measured signal is then compared to the reference signal and processed by matrix laboratory to determine the intruded sector. Information of the intrusion is displayed on an interactive screen implemented by Visual basic. The deformer is designed and implemented using SOLIDWORKS three-dimensional computer aided design Software. Findings The system is tested for intrusions by performing two experiments. The first experiment is performed for both persons (>50 kg) in the lab and cars in an open field with a car moving at 60 km/h using two optical fiber sectors of lengths 200 and 500 m. For test purposes, the deformer length used in the experiment is 2 m. The used signal processing technique in the first experiment has some limitations and its accuracy is 70% after measuring and recording 100 observations. To overcome these limitations, a second experiment with another technique of signal processing is performed. Research limitations/implications The system can perfectly display consecutive intrusions of the sectors, but in case of simultaneous intrusions of different sectors, which is difficult to take place in real situations, there will be the ambiguity of the number of intruders and the intruded sector. This will be addressed in future work. Suitable and stable laser power is required to get a suitable level of backscattered power. Optimization of the deformer is required to enhance the sensitivity and reliability of the sensor. Practical implications The proposed work enables us to benefit from the ease of implementation and the reduced cost of the intensity-modulated fiber optic sensors because it overcomes the constraints that prevent using the intensity-modulated fiber optic sensors for intrusion detection. Originality/value The proposed system is the first time long-range intensity-modulated fiber optic sensor for intrusion detection.


2011 ◽  
Vol 495 ◽  
pp. 41-44
Author(s):  
Enrico De Cais ◽  
Marco Borotto ◽  
Marco Belloli ◽  
Andrea Bernasconi ◽  
Stefano Manzoni

The fiber optic Bragg grating (FBG) sensors have been recently introduced: they presenta photo-record grating on the fiber itself, which allows the reflection of a certain wavelength of theinput light spectrum. The applied strain is estimated based on changes of the reflected wavelength.The metrological characteristics of FBGs have been tested and compared to strain gages ones, whichrepresent the actual reference measurement systems. It was decided to integrate the measurementsystem directly into a composite material, having achieved good results during the static and dynamictests [1]. We made carbon fiber specimens (two for traction and two for bending tests) with FBGsintegrated into them. The results were surprising: the integration of ``nude'' fiber optic sensor didnot cause damage or deterioration in the quality of measurement, the signal noise was maintained atbaseline levels and response to dynamic stress was definitely comparable to that offered by electricalstrain gauges


2020 ◽  
Vol 315 ◽  
pp. 112338
Author(s):  
M. Gutierrez-Rivera ◽  
D. Jauregui-Vazquez ◽  
J.M. Sierra-Hernandez ◽  
D.F. Garcia-Mina ◽  
Y. Lopez-Dieguez ◽  
...  

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