scholarly journals Pendulum-Type Hetero-Core Fiber Optic Accelerometer for Low-Frequency Vibration Monitoring

Sensors ◽  
2018 ◽  
Vol 18 (8) ◽  
pp. 2528 ◽  
Author(s):  
Hiroshi Yamazaki ◽  
Ichiro Kurose ◽  
Michiko Nishiyama ◽  
Kazuhiro Watanabe
Keyword(s):  
Fiber Optics ◽  
Electromagnetic Interference ◽  
Large Scale ◽  
Fiber Optic ◽  
Low Frequency ◽  
Fiber Optic Sensor ◽  
Vibration Monitoring ◽  
Vibration Measurement ◽  
Displacement Sensor ◽  
Core Fiber

In this paper, a novel pendulum-type accelerometer based on hetero-core fiber optics has been proposed for structural health monitoring targeting large-scale civil infrastructures. Vibration measurement is a non-destructive method for diagnosing the failure of structures by assessing natural frequencies and other vibration patterns. The hetero-core fiber optic sensor utilized in the proposed accelerometer can serve as a displacement sensor with robustness to temperature changes, in addition to immunity to electromagnetic interference and chemical corrosions. Thus, the hetero-core sensor inside the accelerometer measures applied acceleration by detecting the rotation of an internal pendulum. A series of experiments showed that the hetero-core fiber sensor linearly responded to the rotation angle of the pendulum ranging within (−6°, 4°), and furthermore the proposed accelerometer could reproduce the waveform of input vibration in a frequency band of several Hz order.

scholarly journals Pendulum-Type Hetero-Core Fiber Optic Accelerometer for Low-Frequency Vibration Monitoring

2018 ◽  
Author(s):  
Hiroshi Yamazaki ◽  
Ichiro Kurose ◽  
Michiko Nishiyama ◽  
Kazuhiro Watanabe
Keyword(s):  
Fiber Optics ◽  
Electromagnetic Interference ◽  
Large Scale ◽  
Fiber Optic ◽  
Low Frequency ◽  
Fiber Optic Sensor ◽  
Vibration Monitoring ◽  
Vibration Measurement ◽  
Displacement Sensor ◽  
Core Fiber

In this paper, a novel pendulum-type accelerometer based on hetero-core fiber optics has been proposed for structural health monitoring targeting large-scale civil infrastructures. Vibration measurement is a non-destructive method for diagnosing the failure of structures by assessing natural frequencies and other vibration patterns. The hetero-core fiber optic sensor utilized in the proposed accelerometer can serve as a displacement sensor with robustness to temperature changes in addition to immunity to electromagnetic interference and chemical corrosions. Thus the hetero-core sensor inside the accelerometer measures applied acceleration by detecting the rotation of an internal pendulum. A series of experiments showed that the hetero-core fiber sensor linearly responded to the rotation angle of the pendulum ranging within ±5°, and furthermore the proposed accelerometer could reproduce the waveform of input vibration in a frequency band of several Hz order.

Distributed Pressure Sensing as Smart Mat Applications with Hetero-Core Fiber Optic Nerve Sensors

2008 ◽  
Vol 47-50 ◽  
pp. 391-394 ◽  
Author(s):  
M. Nishiyama ◽  
H. Sasaki ◽  
S. Nose ◽  
K. Takami ◽  
K. Watanabe
Keyword(s):  
Electromagnetic Interference ◽  
Fiber Optic ◽  
External Disturbance ◽  
Fiber Optic Sensor ◽  
Optic Fiber ◽  
Pressure Sensing ◽  
Natural Activity ◽  
Pressure Mapping ◽  
Core Fiber ◽  
Distributed Pressure

Distributed pressure sensing schemes for human positioning and plantar mapping is desired to be unconstrained for human activity in their daily life in the form of a floor and mat. On the other hand, an optical fiber has several advantages such as lightweight, minimal material, and resistance to corrosion and electromagnetic interference. Additionally, a novel hetero-core optic fiber nerve sensor is only sensitive to be bending action of the sensor portion and the fiber transmission line is unaffected to external disturbance as pressure and temperature fluctuation because of its single-mode stable propagation scheme. Therefore, the hetero-core fiber optic sensor could be suitable for the distributed pressure sensing in human natural activity and be placed in various sites. In this paper, we proposed several smart mat applications in the form of a thin mat in the floor for human positioning and sole pressure mapping mat using the hetero-core optic fiber sensors. We successfully demonstrated the distributed pressure sensing mat using hetero-core sensors to detect human positioning with their circumstance and sole pressure mapping.

scholarly journals New Methods to Seismic Monitoring: Laboratory Comparative Study of Michelson Fiber-Optic Interferometer and Pneumatic Measurement Systems

Photonics ◽  
2021 ◽  
Vol 8 (5) ◽  
pp. 147
Author(s):  
Martin Stolarik ◽  
Jan Nedoma ◽  
Radek Martinek ◽  
Stanislav Kepak ◽  
Eva Hrubesova ◽  
...  
Keyword(s):  
Fiber Optics ◽  
Fiber Optic ◽  
International System ◽  
Physical Principle ◽  
Vibration Monitoring ◽  
Vibration Measurement ◽  
Promising Alternative ◽  
Seismic Engineering ◽  
System Of Units ◽  
Fiber Optic Interferometer

New possibilities of vibration monitoring can be found in completely different physical approaches, where all measuring technology is currently based on sensors in the electrical domain. This paper presents two different promising alternative approaches to vibration measurement, specifically in the field of fiber-optics and pneumatic sensors. The proposed solution uses a Michelson fiber-optic interferometer designed without polarization fading and with operationally passive demodulation technique using three mutually phase-shifted optical outputs. Experimentally developed sensor systems for the registration of anthropogenic seismic phenomena were complemented by standard instrumentation for measuring seismicity used as a standard. The measurement was performed under simplified conditions using a calibrated stroke as a source of dynamic loading. In addition to alternative systems, the paper also presents the results of recalculation of the measured values in a time domain and basic relationships for the conversion to basic units derived from the SI (International System of Units) system and used internationally in the field of seismic engineering. The results presented demonstrate that even systems operating on a different physical principle have great potential to replace the existing seismic devices. The correlation coefficients for both sensory devices were high (above 0.9) and the average deviations from the measured values of the amplitude of the oscillation velocity did not exceed the value of 0.02, neither with the fiber-optic or pneumatic sensor.

A Fiber-Optic Bending Sensor for the Vibration Monitoring of CNC Face-Milling Machine

2009 ◽  
Vol 147-149 ◽  
pp. 627-632
Author(s):  
İsmet Gücüyener ◽  
Erdal Emel
Keyword(s):  
Tool Wear ◽  
Fiber Optic ◽  
Face Milling ◽  
Fiber Optic Sensor ◽  
Vibration Monitoring ◽  
Vibration Measurement ◽  
Milling Machine ◽  
Cnc Milling ◽  
Optic Sensor ◽  
Bending Sensor

Vibration measurement of CNC milling is one of the used techniques for prediction of tool wear. Monitoring of tool wear is very important since a worn tool will affect machine and workpiece either. We developed a fiber-optic sensor for spindle vibration of CNC face-milling machine. The sensor is based on monitoring loss of light from the fiber core. For this sensor a laser light transmitter circuit, a sense plane construction, and a light receiver circuit are designed. Designed fiber-optic sensor is tested on Taksan TMC 650V face-milling machine. Obtained signals from this sensor is investigated in time domain and frequency domain and showed that it is valuable to tool ware monitoring.

scholarly journals 2D Propagation Simulation of Variation Parameters of U-shape Fiber Optic

2020 ◽  
Vol 10 (2) ◽  
pp. 153-158
Keyword(s):  
Fiber Optics ◽  
Power Flow ◽  
Fiber Optic ◽  
Power Transmission ◽  
Simulation Analysis ◽  
Reducing Power ◽  
High Sensitivity ◽  
Curvature Radius ◽  
Sensor Applications ◽  
Core Fiber

Fiber optic has extraordinary properties and is suitable in sensor applications due to its special potential. Currently, macro bending characteristics of newly developed hetero core fiber optic element are designed and evaluated. This paper presents the preliminary results obtained from the numerical simulation analysis of the bending sensitivity of U-shape fiber optics toward the 2D electromagnetic wave in terms of mesh, curvature radius, core fiber size, and turn number. Fiber optics with core sizes of 4, 9, 50, and 62.5 μm were designed. In addition, the combination of core diameters 50-4-50, 50-9-50, 62.5-4-62.5, and 62.5-9-62.5 μm is evaluated to compare the outcome of transmission power in terms of hetero core structure of fiber optic. Simulation is performed using COMSOL Multiphysics simulation tool. The developed U-shape fiber optic is designed to sense the distortion of reducing power transmission by comparing input and output power. Results show that the selected mesh depends on the size of geometry bending fiber optics, and fine and finer mesh is the best for U-shape fiber optic. Furthermore, the power flow on the fiber decreases with the decreasing curvature radius and increasing turn number. The fiber with a core size combination of 62.5–4–62.5 um has high sensitivity in terms of loss. The attained results possess higher potential in the field of sensor applications, such as displacement, strain, pressure, and monitoring respiration, on human body. This study serves as a basis for further investigation of nanomaterial coating on fiber optics, thereby enhancing its credibility for sensing.

Twin-core fiber-optic sensor for simultaneous temperature and strain measurement

1984 ◽  
Author(s):  
J. R. Dunphy ◽  
Gerry Meltz ◽  
M. M. Abou El Leil ◽  
Elias Snitzer
Keyword(s):  
Strain Measurement ◽  
Fiber Optic ◽  
Fiber Optic Sensor ◽  
Optic Sensor ◽  
Core Fiber
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