scholarly journals A Fiber Bragg Grating Based Torsional Vibration Sensor for Rotating Machinery

Sensors ◽  
2018 ◽  
Vol 18 (8) ◽  
pp. 2669 ◽  
Author(s):  
Jingjing Wang ◽  
Li Wei ◽  
Ruiya Li ◽  
Qin Liu ◽  
Lingling Yu
Keyword(s):  
Optical Fiber ◽  
Fiber Bragg Grating ◽  
Torsional Vibration ◽  
Electromagnetic Interference ◽  
Vibration Sensor ◽  
Vibration Measurement ◽  
Bragg Grating ◽  
Structural Parameter ◽  
Measurement Sensitivity ◽  
Fiber System

This paper proposes a new type of torsional vibration sensor based on fiber Bragg grating (FBG). The sensor has two mass ball optical fiber systems. The optical fiber is directly treated as an elastomer and a mass ball is fixed in the middle of the fiber in each mass ball fiber system, which is advantageously small, lightweight, and has anti-electromagnetic interference properties. The torsional vibration signal can be calculated by the four FBGs’ wavelength shifts, which are caused by mass balls. The difference in the two sets of mass ball optical fiber systems achieves anti-horizontal vibration and anti-temperature interference. The principle and model of the sensor, as well as numerical analysis and structural parameter design, are introduced. The experimental conclusions show that the minimum torsional natural frequency of the sensor is 27.35 Hz and the torsional vibration measurement sensitivity is 0.3603 pm/(rad/s2).

scholarly journals Fiber Bragg Grating and Channel Spacing Effect in WDM Radio over Fiber System Using DPSK Modulation Format

2018 ◽  
Vol 7 (3.4) ◽  
pp. 218 ◽  
Author(s):  
Hussein Ahmed Mahmood ◽  
Riyadh Khlf Ahmed
Keyword(s):  
Optical Fiber ◽  
Fiber Bragg Grating ◽  
Optical Communication ◽  
System Performance ◽  
Dispersion Compensation ◽  
Radio Over Fiber ◽  
Bragg Grating ◽  
Fiber System ◽  
Channel Spacing ◽  
Radio Over Fiber System

Fiber Bragg Grating (FBG) is distributed reflector written in short length of optical fiber to reflect specific wavelengths of light and transmit the other components of spectra. By using FBG method in dispersion compensation can boost significantly the system performance. High capacity transmission and low effective cost of Radio over Fiber technique (Rof) are resulted from the combination of the optical communication capacity and the mobility of wireless networks. In this research article, an investigation of radio over fiber transmission for 50 km-long optical fiber operated at 10 Gb/s data rate and modulated under efficient DPSK modulation technique. The effect of Fiber Bragg Grating as chromatic dispersion compensation and channel spacing in WDM on optical communication system is analyzed and evaluated. The system performance is evaluated in terms of eye diagram. The outcomes of our simulation shows that Four unequal spacing channels radio over fiber system with ideal dispersion FBG has the best performance in terms of Q-factor and BER.  

The Fiber Measuring Method for Rotating Parts Comprehensive Vibration

2012 ◽  
Vol 201-202 ◽  
pp. 87-90
Author(s):  
Ping Xiong ◽  
Deng Feng Zhao ◽  
Guo Ying Zeng ◽  
Juan Huang
Keyword(s):  
Optical Fiber ◽  
Torsional Vibration ◽  
Measuring Method ◽  
Laser Doppler ◽  
Vibration Measurement ◽  
Measurement Technology ◽  
Doppler Measurement ◽  
Rotating Shaft ◽  
Fiber System ◽  
Bending Vibration

Light propagation in the air is easily affected by the environment. Shaft bending vibration and torsional vibration are needed to be measured at the same time. The different vibration state are coupled each other. For these reasons, it is necessary to design the optical fiber laser Doppler measurement system and develop the integrated optical fiber system, which is in favor of various vibration modes decoupling and can improve the signal-to-noise ratio. The double parallel beam differential scheme is adopted in the torsional vibration measurement, which the light exposed in the air is coupled into the optical fiber. The optical fiber heterodyne Doppler interference measuring method is adopted in the bending vibration measurement. The laser Doppler vibration measurement technology is applied to a rotating shaft vibration measurement. Comprehensive measuring technology is developed, which can simultaneously measure bending vibration, torsional vibration and the rotation speed of shaft.

scholarly journals Fiber Optic Vibration Sensor Based on the Tilted Fiber Bragg Grating

2013 ◽  
Vol 2013 ◽  
pp. 1-4 ◽  
Author(s):  
Jiali An ◽  
Tao Liu ◽  
Yongxing Jin
Keyword(s):  
Fiber Bragg Grating ◽  
Fiber Optic ◽  
Average Power ◽  
Single Mode ◽  
Single Mode Fiber ◽  
Vibration Sensor ◽  
Vibration Measurement ◽  
Bragg Grating ◽  
Average Output ◽  
Cladding Mode

A temperature-insensitive fiber optic vibration sensor based on the tilted fiber Bragg grating (TFBG) is presented. The sensing head is formed by insertion of a small section of MMF between a single-mode fiber and the TFBG. The reflection light from this tilted fiber Bragg grating includes two parts: the reflected Bragg mode and the cladding modes. The cladding modes were coupled back into the core mode as a function of the multimode fiber. The power of the cladding modes is sensitive to vibration, so the external vibration measurement can be obtained through the cladding mode average output power. Experiment results show that the root mean square (RMS) of the detection error of the average power was 0.01 μW within the temperature range from 20 to 70°C, so it is proved to be temperature independent; its frequency response has been tested to 1 KHz.

scholarly journals Optimal Analysis of 40 Gbps Dispersion Compensated Optical Fiber System

2021 ◽  
Vol 12 (1) ◽  
pp. 66
Author(s):  
Murad Hassan ◽  
Arslan Arif
Keyword(s):  
Optical Fiber ◽  
Fiber Bragg Grating ◽  
Communication Systems ◽  
Optical Fiber Communication ◽  
Data Rate ◽  
Bragg Grating ◽  
Fiber System ◽  
Long Distance ◽  
Modulation Format ◽  
Dispersion Compensator

Dispersion is one of the main factors that limit the development of optical fiber communication systems regarding data rate and long distance transmission of the signal. This is because of increases in dispersion with the increase in data rate and distance, resulting in signal degradation. In this work, we propose an optimal dispersion compensated optical fiber system, which is designed on the basis of Q-factor, eye height, and bit error rate. The system operates at a bit rate of 40 Gbps and a distance of 100 km. According to the optimization scheme, the system is simulated using the modulation format Non Return to Zero (NRZ) with uniform and Linear Chirped Apodized Fiber Bragg Grating (LCAFBG) as dispersion compensator. After deciding the Fiber Bragg Grating (FBG) structure, other key parameters are simulated to meet the requirements. The simulation results show that using NRZ modulation format with a LCAFBG Tanh profile gives better performance.

scholarly journals Fiber Bragg Grating Sensors for Underwater Vibration Measurement: Potential Hydropower Applications

Sensors ◽  
2021 ◽  
Vol 21 (13) ◽  
pp. 4272
Author(s):  
Oscar de la Torre ◽  
Ignazio Floris ◽  
Salvador Sales ◽  
Xavier Escaler
Keyword(s):  
Fiber Bragg Grating ◽  
Numerical Models ◽  
Vibration Measurement ◽  
Quality Data ◽  
Bragg Grating ◽  
Laser Vibrometer ◽  
Main Concern ◽  
High Expectations ◽  
Fiber Bragg Grating Sensors ◽  
Hydraulic Machinery

The present paper assesses the performance and characteristics of fiber Bragg grating sensors, with a special interest in their applications in hydraulic machinery and systems. The hydropower industry is turning to this technology with high expectations of obtaining high quality data to validate and calibrate numerical models that could be used as digital twins of key assets, further strengthening the sector’s relevant position within industry 4.0. Prior to any validation, fiber Bragg grating sensors’ ability to perform well underwater for long periods of time with minimal degradation, and their ease of scalability, drew the authors´ attention. A simplified modal analysis of a partially submerged beam is proposed here as a first step to validate the potential of this type of technology for hydropower applications. Fiber Bragg grating sensors are used to obtain the beam’s natural frequencies and to damp vibrations under different conditions. The results are compared with more established waterproof electric strain gauges and a laser vibrometer with good agreement. The presence of several sensors in a single fiber ensures high spatial resolution, fundamental to precisely determine vibration patterns, which is a main concern in this industry. In this work, the beam’s vibration patterns have been successfully captured under different excitations and conditions.

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