A string of fiber-optic sensors running along a 36-km stretch of high-speed commuter railroad lines connecting Hong Kong to mainland China has taken more than 10 million measurements over the past few years in a demonstration that the system can help safeguard commuter trains and freight cars against accidents.
Attuned to the contact between trains and tracks, the sensors can detect potential problems like excessive vibrations, mechanical defects or speed and temperature anomalies. The system is wired to warn train operators immediately of such problems so that they can avoid derailments or other accidents, said Hwa-yaw Tam of the Hong Kong Polytechnic University, who will describe the technology and its test run next week at The Optical Society's (OSA) Annual Meeting, Frontiers in Optics (FiO) 2013, being held Oct. 6-10 in Orlando, Fla.
At least 30 times during the seven-year period, the system detected anomalous vibrations, Tam said. In a few cases, the vibrations turned out to be early warnings of dangerous emerging conditions that could have led to train wrecks. In some cases, vibration due to the use of the wrong type of lubrication oil in axle boxes was detected. The fiber-optic sensor system was designed for maintenance purposes and saves the rail company about $250,000 every year in maintenance costs.
"Using just this one type of technology, we are able to measure many things," Tam said. "This technology is perfect for railway systems." He added that it costs less than a third the price of other warning systems, which typically require data to be integrated from a half dozen different types of monitoring systems.
The system is now being installed in all commuter train routes in Hong Kong and will soon be rolled out in railways in parts of Singapore and Australia. With regular speeds for some of the trains in China topping out above 300 km per hour, the need for effective safety measures is profound, Tam said.
Worldwide, the rail industry is undergoing a major development boom, especially in places like China where tens of thousands of kilometers of new high-speed lines are planned for the next decade at an estimated cost of hundreds of billions of dollars.
How the System Works
The basis for the new sensor system is a technology developed in the 70s and 80s known as a Fiber Bragg grating, a type of sensor that reflects narrow spectra of light whose wavelengths shift due to temperature/strain variation. Coupling fiber Bragg gratings with another device known as mechanical transducers allows pressure, acceleration and other parameters to be measured.
The sensors are imbedded in mechanical compartments of a train or along the tracks. If there is a defect, like a sudden break in the rails or excessive vibrations because the weight of the train is off balance, those changes will alter the reflection spectra of FBGs in a detectable way.
The system is advantageous because it is all-optical, allowing the passive fiber Bragg grating sensors to monitor conditions along a train route, Tam said. It also relies exclusively on optical detection and communication, so there are no problems with electromagnetic interference from power lines that run parallel to many modern rail lines.
Presentation FW2I.3, "Distributed Optical Fiber Sensing Networks for Railway Monitoring," takes place Wednesday, Oct. 9 at 11:30 a.m. EDT at the Bonnet Creek Ballroom, Salon X at the Hilton Bonnet Creek in Orlando, Fla.
PRESS REGISTRATION: A press room for credentialed press and analysts will be located in the Hilton Bonnet Creek, Sunday through Thursday, Oct. 6-10. Those interested in obtaining a press badge for FiO should contact OSA's Lyndsay Meyer at 202.416.1435 or email@example.com.
About the Meeting
Frontiers in Optics (FiO) 2013 is the Optical Society's (OSA) 97th Annual Meeting and is being held together with Laser Science XXIX, the annual meeting of the American Physical Society (APS) Division of Laser Science (DLS). The two meetings unite the OSA and APS communities for five days of quality, cutting-edge presentations, fascinating invited speakers and a variety of special events spanning a broad range of topics in optics and photonics—the science of light—across the disciplines of physics, biology and chemistry. An exhibit floor featuring leading optics companies will further enhance the meeting. More information at http://www.FrontiersinOptics.org.
Founded in 1916, The Optical Society (OSA) is the leading professional society for scientists, engineers, students and business leaders who fuel discoveries, shape real-world applications and accelerate achievements in the science of light. Through world-renowned publications, meetings and membership programs, OSA provides quality research, inspired interactions and dedicated resources for its extensive global network of professionals in the optics and photonics field. For more information, visit http://www.osa.org.
Lyndsay Meyer | Source: EurekAlert!
Further information: www.osa.org
Further Reports about: Fiber Optic Cables > fiber-optic sensor system > fiber-optic sensors > high-speed lines > laser system > monitoring system > monitoring systems > optical data > optical detection > Optical Fiber Sensing Networks > sensor system > warn train operators
More articles from Physics and Astronomy:
NASA's SDO Shows the Sun's Rainbow of Wavelengths
18.12.2013 | NASA's Goddard Space Flight Center
Clot-Busters, Caught on Tape
17.12.2013 | American Institute of Physics (AIP)
A 12-year study of massive stars has reaffirmed that our Galaxy has four spiral arms, following years of debate sparked by images taken by NASA's Spitzer Space Telescope that only showed two arms.
The new research, which is published online today [17 December] in the Monthly Notices of the Royal Astronomical Society, is part of the RMS Survey, which was launched by academics at the University of Leeds.
Astronomers cannot see what our Galaxy, which is called the Milky Way, looks like because we ...
In collaboration with the University of Basel, an international team of researchers has observed a strong energy loss caused by frictional effects in the vicinity of charge density waves.
This may have practical significance in the control of nanoscale friction. The results have been published in the scientific journal Nature Materials.
Friction is often seen as an adverse phenomenon that leads to wear and causes energy loss. Conversely, however, too little friction can be a disadvantage as well – ...
A new type of transistor that could make possible fast and low-power computing devices for energy-constrained applications such as smart sensor networks, implantable medical electronics and ultra-mobile computing is feasible, according to Penn State researchers.
Called a near broken-gap tunnel field effect transistor (TFET), the new device uses the quantum mechanical tunneling of electrons through an ultrathin energy barrier to provide high current at low voltage.
Penn State, the National Institute of Standards and Technology and IQE, a specialty wafer manufacturer, jointly presented their findings at ...
The team of Johannes Zuber at the IMP in Vienna, Austria, managed to overcome remaining key limitations of RNA interference (RNAi) - a unique method to specifically shut off genes.
By using an optimized design, the scientists were able to inhibit genes with greatly enhanced efficiency and accuracy. The new method facilitates the search for drug targets and improves the interpretation of experimental results.
The IMP will make this „RNAi toolkit“ available to researchers. Results of the study are published in ...
Research The dangerous parasite Schistosoma mansoni that causes snail fever in humans could become significantly less common in the future a new international study led by researchers from the University of Copenhagen predicts.
The results are surprising because they contradict the general assumption that climate change leads to greater geographical spread of diseases. The explanation is that the parasite’s host snails stand to lose suitable habitat due to climate change.
“Our research shows that the expected effects of climate change will lead ...
18.12.2013 | Life Sciences
18.12.2013 | Medical Engineering
18.12.2013 | Studies and Analyses
11.12.2013 | Event News
10.12.2013 | Event News
05.12.2013 | Event News