Electrical - Electronic Engineering / Elektrik - Elektronik Mühendisliği
Permanent URI for this collectionhttps://hdl.handle.net/11147/11
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Article Citation - WoS: 7Citation - Scopus: 10Analysis of Crosstalk Effects in Phase-Otdr System Using Fiber Bragg Grating Array(Elsevier, 2023) Koçal, Ertunga Burak; Yüksel, Kıvılcım; Wuilpart, MarcIn this paper, the parasitic components (i.e., multi-reflections, Rayleigh scattering, photodetector noise, and phase variations due to external perturbations) are analysed and based on this analysis, a new signal to noise ratio (SNR) definition is provided suitable for the FBG-assisted Phase-OTDR system. A detailed analysis of performance parameters in the presence of multi reflection crosstalk (including its first- and second-order components) and spectral shadowing crosstalk is presented. SNR was calculated for different reflectivity and spacing lengths showing that the maximum number of cascaded FBGs can be significantly increased by using lower FBG reflectivity. It was also observed that the spacing length distance does not have a significant impact on the maximum number of FBGs that can be interrogated. By comparing single-pulse and double-pulse configurations, the use of double pulse was shown to provide higher SNR values when the number of FBGs is around 100 FBGs. The multi-reflection crosstalk when combined with the spectral-shadowing effect was demonstrated to create secondary crosstalk components making the interpretation of spectral analysis more difficult.Article Citation - WoS: 3Citation - Scopus: 3Current Sensing Using a Phase-Sensitive Optical Time Domain Reflectometer: Feasibility Study(Elsevier, 2022) Wuilpart, Marc; Şirin, Şamil; Yüksel Aldoğan, KıvılcımA novel method for distributed current sensing using an FBG-assisted Phase-OTDR with Mach-Zehnder Interferometer is proposed. The detrimental effect of the intrinsic linear birefringence of the sensing fiber is solved by calibration. An FBG pair is written at the two ends of the spun fiber coil to eliminate phase fading and increase the measurement accuracy. A simulation tool was developed to reveal the feasibility of the approach by investigating the impact of the detector noise as well as the effects of bending- and FBG-induced linear birefringence on the sensing performance.Article Citation - WoS: 101Citation - Scopus: 129Scientific Applications of Distributed Acoustic Sensing: State-Of Review and Perspective(MDPI, 2022) Gorshkov, Boris G.; Yüksel, Kıvılcım; Fotiadi, Andrei A.; Wuilpart, Marc; Korobko, Dmitry A.; Zhirnov, Andrey A.; Lobach, Ivan A.This work presents a detailed review of the development of distributed acoustic sensors (DAS) and their newest scientific applications. It covers most areas of human activities, such as the engineering, material, and humanitarian sciences, geophysics, culture, biology, and applied mechanics. It also provides the theoretical basis for most well-known DAS techniques and unveils the features that characterize each particular group of applications. After providing a summary of research achievements, the paper develops an initial perspective of the future work and determines the most promising DAS technologies that should be improved.Conference Object Citation - WoS: 14Citation - Scopus: 14An Overview of the Recent Advances in Fbg-Assisted Phase-Sensitive Otdr Technique and Its Applications(IEEE, 2020) Yüksel, Kıvılcım; Koçal, Ertunga Burak; Jason, Johan; Wuilpart, Marc; Sainz, Manuel Lopez-AmoIn this paper, we discuss the operation principles, sensing mechanism, challenges and application areas of FBG-assisted phase-sensitive optical time-domain reflectometry. A special emphasis is given to the interrogation of fiber Bragg grating arrays for vibration sensing application. Results obtained by different research groups are compared in terms of performance characteristics and future perspectives. Recent progress obtained through our research collaboration are also presented. In particular, the detrimental spectral shadowing effect and multiple reflection crosstalk are analysed and mitigation techniques are proposed. © 2020 IEEE.Article Citation - WoS: 26Citation - Scopus: 27Implementation of a Mobile Platform Based on Fiber Bragg Grating Sensors for Automotive Traffic Monitoring(MDPI, 2020) Yüksel, Kıvılcım; Kinet, Damien; Chah, Karima; Caucheteur, ChristopheInstrumentation techniques, implementation and installation methods are major concerns in today's distributed and quasi-distributed monitoring applications using fiber optic sensors. Although many successful traffic monitoring experiments have been reported using Fiber Bragg Gratings (FBGs), there has been no standardized solution proposed so far to have FBG seamlessly implemented in roads. In this work, we investigate a mobile platform including FBG sensors that can be positioned on roads for the purpose of vehicle speed measurements. The experimental results prove the efficiency of the proposed platform, providing a perspective toward weigh-in-motion systems.Conference Object Ф-otdr Sorgulayıcı Tabanlı Titreşim Algılayıcılar için Simülasyon Aracı Geliştirilmesi(Institute of Electrical and Electronics Engineers Inc., 2019) Şirin, Şamil; Yüksel Aldoğan, KıvılcımBu çalışmada, faza duyarlı zaman bölgesinde optik yansıtıcı ünitesi tarafından sorgulanan fiber optik titreşim sensörü simülasyon aracı geliştirilmesi amacıyla, literatürde yakın zamanda önerilen modüler bir yaklaşım uygulanmıştır. Geliştirilen model kullanılarak, demodüle edilen faz bilgisi üzerindeki faz sönümleme etkisi incelenmiştir.Article Citation - WoS: 62Citation - Scopus: 70Railway Monitoring System Using Optical Fiber Grating Accelerometers(IOP Publishing Ltd., 2018) Yüksel, Kıvılcım; Kinet, Damien; Moeyaert, Veronique; Kouroussis, Georges; Caucheteur, ChristopheOptimal operation, reduced energy consumption, longer service availability, and high safety level are the major concerns in today's railway transport systems. Smart monitoring systems should address these issues without interrupting railway operability. Many successful works have been carried out to provide railway monitoring functions using fiber Bragg grating (FBG) sensors on rail. Most of them are based on strain measurement due to the train passage. This paper presents a highly sensitive means for railway monitoring based on vibration measurement. FBG accelerometers placed on sleeper have been employed as sensor heads, which significantly facilitated the field sensor installation work compared to the positioning on the foot of the rail. An optimized signal demodulation algorithm has been effectively used to extract from the accelerometer traces both the axle number and the average speed information. Excellent capability of the developed system to obtain both parameters has been demonstrated by the way of field trials carried out on a Belgian railway line, during its normal operation. Easy installation, multi-function diagnosis, good data integrity, and compatibility with fiber optic sensors make the proposed sensor a good candidate for railway monitoring applications.Article Development of a Phase-Otdr Interrogator Based on Coherent Detection Scheme(Uludağ Üniversitesi, 2018) Yüksel, Kıvılcım; Jason, Johan; Wuilpart, MarcWe present in this work, the experimental demonstration of a phase-sensitive Optical Time- Domain Reflectometer (phase-OTDR) having coherent detection scheme. An analysis algorithm has also been developed to calculate amplitude and phase evolution of the experimental phase-OTDR traces. The efficiency of the analysis algorithm to determine the position of the applied vibration has been verified for a single and two simultaneous vibrations. The slow-time analysis results show a good agreement with the mathematical calculations discussed in the paper. This work could have a technological implication in many fields such as distributed vibration sensor for railway monitoring applications.Conference Object Rayleigh-Based Optical Reflectometry Techniques for Distributed Sensing Applications(Selçuk Üniversitesi, 2018) Yüksel, KıvılcımIn this paper, we discuss the operation principles, sensing mechanisms, challenges and application areas of the optical reflectometry techniques exploiting Rayleigh scattering phenomenon, considering both time- and frequency-domain schemes. Among various distributed optical fiber sensor (DOFS) systems interrogated by optical reflectometry techniques, a special emphasis was given, in this paper to distributed acoustic sensor (DAS) interrogation methods. Recent progresses obtained through our research collaborations are also presented.Article Citation - WoS: 14Citation - Scopus: 15Analytical Investigation of a Novel Interrogation Approach of Fiber Bragg Grating Sensors Using Optical Frequency Domain Reflectometry(Elsevier Ltd., 2016) Yüksel, Kıvılcım; Pala, DenizThis work presents a novel approach in interrogating Polarization Dependent Loss (PDL) of cascaded identical FBGs using Optical Frequency Domain Reflectometer (OFDR). The fundamentals of both polarisation properties of uniform FBGs and polarisation-sensitive OFDR are explained and the benefits of this novel approach in measuring transversal load are discussed. The numerical programs computing the spectral evolution of PDL of the FBGs in the array as a function of grating parameters (grating length and birefringence) are presented. Our simulation results show an excellent agreement with the previously reported simulation (and experimental) results in the literature obtained on a single FBG by using classical state-of-the-art measurement techniques. As an envisaged application, the proposed system shows the feasibility of measuring the residual stresses during manufacturing process of composite materials which is not straightforward by amplitude spectrum measurements and/or considering only the axial strains. © 2016 Elsevier Ltd. All rights reserved.