scholarly journals Secure Software for Rail Circuits in the Form of Distributed Sensors

2021 ◽  
Vol 18 ◽  
pp. 20-25
Author(s):  
Nikoloz Mgebrishvili ◽  
Maksim Iavich ◽  
Giorgi Iashvili ◽  
Amiran Nodia
Keyword(s):  
Fault Location ◽  
Fiber Optic ◽  
Mechanical Damage ◽  
Light Signal ◽  
Rolling Stock ◽  
Fiber Optic Cable ◽  
Distributed Sensors ◽  
Optical Time Domain Reflectometer ◽  
Simulation Techniques ◽  
Optical Time

In order to improve the safety of train traffic, we propose to introduce into practice a new type of rail circuits, fiber-optic rail circuits. Fiber optic cable is very sensitive to external shocks, vibration and deformation, which can play a crucial role in the detection of mechanical damage of rails and wheel sets and also to improve the positioning of the rolling stock. The branches of the fiber optic cable not only serve as a conductor of information, but also serve as a sensor, as they can perceive vibration. An OTDR (Optical Time Domain Reflectometer) analyzes the backscattered light signal to determine the shape of the physical impact that caused the bending. From the time between the emission of the light signal and the receipt of the backscattered signal, the fault location is calculated. The authors offer the model of the system, which will check the security problems of the trains and the rail circuits. The software of the corresponding system is presented, using the simulation techniques. The authors present the pseudo code of the software. They also offer the testing environment for the software.

scholarly journals Analisis Link Budget Penyambungan Serat Optik Menggunakan Optical Time Domain Reflectometer AQ7275

2018 ◽  
Vol 10 (1) ◽  
pp. 36-40
Author(s):  
Tio Hanif Yanuary ◽  
Lita Lidyawati
Keyword(s):  
Optical Fiber ◽  
Fiber Optics ◽  
Time Domain ◽  
High Speed ◽  
Fiber Optic ◽  
Light Wave ◽  
Fiber Optic Cable ◽  
Optical Time Domain Reflectometer ◽  
Optical Time ◽  
Time Domain Reflectometer

An optical fiber is a high-speed telecommunication transmission medium. Principally, an optical fiber is made of a very fine glass fiber material, which is able to transmit light waves using light reflection method on the surface of the fiber optics core. An underground installation of the fiber optics makes this device robust from external interferences. However, the fiber optic cable performance should always be checked to maintain performance during data transmission process. One way to test fiber optics cable performance is by using an Optical Time - Domain Reflectometer (OTDR) device. This device sends a light wave from one point of the fiber optics cable. The light wave then returns when reaching the other point of the fiber optic cable while carrying some measurement parameters especially the physical length and attenuation of a fiber optic cable. The evaluation of the fiber optics cable performance requires the preparation, installation, and configuration of the OTDR. In this paper, we conducted evaluation on the performances of fiber optics cable. The data generated by the performed evaluation indicated an occurring attenuation on the fiber optics cable along 64.402 km of its lengths.

LabVIEW Applications for Fiber-Optic Remote Test and Fiber Sensor Systems

2014 ◽  
Vol 610 ◽  
pp. 216-220
Author(s):  
Liang Yu Su
Keyword(s):  
Time Domain ◽  
Fiber Optic ◽  
Fiber Optic Sensor ◽  
Fiber Sensor ◽  
Optic System ◽  
Optical Time Domain Reflectometer ◽  
Optic Sensor ◽  
Optical Time ◽  
Fiber Optic System ◽  
Time Domain Reflectometer

This paper demonstrates applications of LabVIEW in automatic test measurement of fiber optic system.First,the LabVIEW applications in fiber optic system and the basics of instrument connectivity are presented.Then,the aspects of hardware communication to external instruments through GPIB and serial interfaces are analyzed.Next,self-calibrating automated characterization system for depressed cladding applications is demonstrated utilizing the LabVIEW’s GPIB interface. Results of the manual and automatic measurements and the analysis of the measurement trace obtained from the optical time domain reflectometer (OTDR) are shown.In the end,two applications of LabVIEW in fiber optic sensor system are discussed.

Multiplexed Fiber Optic Temperature Monitoring Sensor Using Hard-Polymer-Clad Fiber and an Optical Time-Domain Reflectometer

2013 ◽  
Author(s):  
Hyeong Cheol Kim ◽  
Jung-Ryul Lee
Keyword(s):  
Time Domain ◽  
Fiber Optic ◽  
Optical Loss ◽  
Sensor Nodes ◽  
Optical Time Domain Reflectometer ◽  
Sensing Systems ◽  
Hard Polymer ◽  
Optical Time ◽  
Time Domain Reflectometer ◽  
Fiber Optic Temperature

Optical fiber temperature sensing systems have incomparable advantages than the traditional electric cable based monitoring systems. As of now, fiber Bragg grating (FBG) sensors are most popular because of its wavelength domain multiplexing capability. However, grating writing process is complex and takes long time and photosensitive fibers for the typical grating writing process are expensive. In addition, sensing systems for FBGs are also expensive. Therefore, this study proposes multiplexed fiber optic temperature monitoring sensor system using an economical Optical Time-Domain Reflectometer (OTDR) and Hard-Polymer-Clad Fiber (HPCF). HPCF is a specific type of optical fiber, in which a hard polymer cladding made of fluoroacrylate acts as a protective coating for an inner silica core. An OTDR is an optical loss measurement system that provides optical loss and event distance measurement in real time. Multiplexed sensor nodes were economically and quickly made by locally stripping HPCF clad through photo-thermal and photo-chemical processes using a continuous/pulse hybrid-mode laser with 10 m intervals. The core length exposed was easily controlled by adjusting the laser beam diameter, and the exposed core created a backscattering signal in the OTDR attenuation trace. The backscattering peak was sensitive to the temperature variation. Since the elaborated HPCF temperature sensor was insensitive to strain applied to the sensor node and to temperature variation in the normal HPCF line, neither strain compensation nor isolation technique are required. These characteristics are important advantages for the use as structure-integrated temperature sensors. The performance characteristics of the sensor nodes include an operating range of up to 120 C, a resolution of 1.52 C, a tensile strain resistance of 13%.

All-Fiber Optic Chemical Sensors for Public Safety Monitoring

2010 ◽  
Vol 123-125 ◽  
pp. 855-858 ◽  
Author(s):  
Jung Ryul Lee ◽  
Chang Yong Yoon ◽  
Dipesh Dhital ◽  
Dong Jin Yoon
Keyword(s):  
Public Safety ◽  
Chemical Sensor ◽  
Fiber Optic ◽  
Inner Core ◽  
Light Signal ◽  
Chemical Substances ◽  
Optical Time Domain Reflectometer ◽  
Sensing System ◽  
Hard Polymer ◽  
Light Loss

The leakage of toxic or flammable chemical substances that might affect or endanger public safety has always attracted the attention of the researchers to develop a chemical sensor that could prevent any life-threatening incidents. Due to its robust features, hard polymer clad fiber (HPCF) was used in this experiment to develop an all-fiber optical chemical sensor. The outer hard polymer clad was removed by using mechanical method to expose the inner core. The exposure lets contact between the leaked chemical and the core, both with different refractive indices (RI). The change in signal property of the passing light wave occurs at this point and hence can be detected using optical time-domain reflectometer (OTDR). In this way, HPCF was transformed into a fiber optic chemical sensor. OTDR was used as a sensing system that allowed the sensor to detect and localize the leakage of chemical substances in real-time, by measuring the light loss in backscattering light (signal) that was caused due to extraction of chemical on fiber cladding. This light loss is based on leaky wave mode principle. The reliability of the sensor was tested with Benzene, Toluene, Pyridine, Dimethylsulphoxide and several other toxic chemicals. The results showed that the sensor was able to detect the chemicals (in liquid state) and localize the event positioning. With the promising results, the sensor will be further tested with different types of chemicals to optimize the fiber chemical sensing system.

scholarly journals An Application of BOTDR to the Measurement of the Curing of a Bored Pile

2021 ◽  
Vol 11 (1) ◽  
pp. 418
Author(s):  
Lei Gao ◽  
Chuan Han ◽  
Omar Abdulhafidh ◽  
Yunhao Gong ◽  
Yingjie Jin
Keyword(s):  
Fiber Optic ◽  
Fiber Optic Sensor ◽  
Monitoring Method ◽  
Optical Time Domain Reflectometer ◽  
Bored Pile ◽  
Sensing Technology ◽  
Reliable Monitoring ◽  
Distributed Fiber Optic Sensor ◽  
Optical Time ◽  
Pile Deformation

In order to study the deformation of a bored pile during concrete curing, it is necessary to monitor the strain of the pile. In this paper, Brillouin optical time domain reflectometer (BOTDR) technology is used to monitor the pile strain during concrete curing, and reliable monitoring data are obtained. These data provide a basis for the study of pile deformation and pile–soil interaction during curing of bored cast-in-place piles. Compared with the traditional point strain sensor, the distributed fiber optic sensor is simple in layout and highly accurate; it can fully reflect the strain changes of the pile; the experiment also shows the advantages of distributed fiber optic sensing technology over the traditional point monitoring method.

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