Interrogation System With Automatic Recognition and Delay Correction Functions of Fiber Bragg Gratings by Pulse Modulation With Wavelength-Swept Laser

Yamaguchi, Tatsuya; Endo, Wataru; Shinoda, Yukitaka

doi:10.1109/jsen.2019.2933812

Cited by 10 publications

(10 citation statements)

References 32 publications

(22 reference statements)

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“…As for composition questions and oral questions, automatic revision is still the research focus that should be broken through. Oral problems can be divided into two types [3]. One is retelling, reading aloud, and reciting what is known.…”

Section: Introductionmentioning

confidence: 99%

Automatic Scoring of Spoken Language Based on Basic Deep Learning

Zhong

Zong-hua

2022

Scientific Programming

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The oral English test in domestic universities requires teachers to modify a large number of candidates’ oral recordings. This is the work of using time repeatedly. Using the CALL system to realize the automation of conversation recording can reduce the burden of teachers’ work. Therefore, it is of great practical significance to develop an automatic and accurate scoring system for oral English. With the development of artificial intelligence, deep learning technology has been gradually applied in various fields. Similarly, in the application of oral scoring, deep learning technology makes the implementation of such a system possible. Based on the deep learning technology, this paper proposes an automatic scoring algorithm for spoken language and implements a detailed design and evaluation system. The system consists of two modules. The pronunciation standard of spoken pronunciation and the content of spoken pronunciation are scored, and the sum of these two scores is the final score. Finally, this paper uses 650 oral English recordings from a college English test to train the artificial neural network. Experimental results show that if the training data set is small, the BP network model can obtain better comprehensive evaluation performance.

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Section: Introductionmentioning

confidence: 99%

Automatic Scoring of Spoken Language Based on Basic Deep Learning

Zhong

Zong-hua

2022

Scientific Programming

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“…To install FBGs at long distances or large intervals, correction methods by modulating the sweep rates of wavelength-swept lasers have been reported [33]. We introduced a delay correction method that used pulse modulation with wavelength-swept lasers to automatically recognize reflection signals from multiple FBGs installed at arbitrary long distances and removed delays [34].…”

Section: Introductionmentioning

confidence: 99%

High-Speed Interrogation System for Fiber Bragg Gratings With Buffered Fourier Domain Mode-Locked Laser

2021

Self Cite

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We develop a high-speed interrogation system with a wavelength-swept laser for sensing multiplexed fiber Bragg gratings (FBGs). High-speed and multipoint sensing is achieved by means of a buffered Fourier domain mode-locked (FDML) laser, a recently proposed high-speed wavelength-swept laser. This laser increases the measurement rate several times by tailoring the laser output with a buffer stage. The developed buffered FDML laser successfully achieves a measurement rate of 202.8 kHz using a general FDML laser driven at a sweep rate of 50.7 kHz. In order to detect reflection signals of FBGs at the high measurement rate, the measurement system introduces digital signal processing using a field programmable gate array (FPGA). However, FBG measurements with wavelength-swept lasers are affected by the propagation time (delay) in the optical fiber connecting from the laser to the FBG sensor, which reduces measurement accuracy. To overcome this limitation, the developed system uses a delay correction method with bidirectional sweep of the buffered FDML laser. The interrogation system with the buffered FDML laser achieves a time resolution of 4.9 µs without being affected by the delay.

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“…PWM is a modulation technique that generates variable-width pulses to represent the amplitude of an analog input signal [ 27 ]. In [ 28 ], an interrogation system is presented based on pulse-modulation, that automatically recognized reflection signals of FBGs even when the FBGs are installed in an arbitrary order or at a long distance and affected by delays. This recognition technique was realized using pulse-modulating in the wavelength-swept laser.…”

Section: Introductionmentioning

confidence: 99%

“…This recognition technique was realized using pulse-modulating in the wavelength-swept laser. However, in contrast to [ 28 ], our proposed scheme has a tunable laser that sweeps a pre-set wavelength band where the FBG sensors work in continuous-wave (CW) mode. The demodulator using robust electronic devices can be used near the engine, near the pressure sensor and even integrated with the ECU to transform the wavelength variation-based signal, to a PWD signal and finally in an analog intensity signal compatible with the ECU input port.…”

Section: Introductionmentioning

confidence: 99%

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

Rosolem

Argentato

Bassan

et al. 2020

Sensors

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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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Interrogation System With Automatic Recognition and Delay Correction Functions of Fiber Bragg Gratings by Pulse Modulation With Wavelength-Swept Laser

Cited by 10 publications

References 32 publications

Automatic Scoring of Spoken Language Based on Basic Deep Learning

Automatic Scoring of Spoken Language Based on Basic Deep Learning

High-Speed Interrogation System for Fiber Bragg Gratings With Buffered Fourier Domain Mode-Locked Laser

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

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