EC Contract No. FP7 - 234299
D5.1
State of the Art Application to Railways Instrumentation
Due date of deliverable: 31/01/2010
Actual submission date: 11/08/2010
Leader of this Deliverable: P Kitson, Corus
Reviewed: N
Document status
Revision
Date
Description
1
17/5/2010
First issue
2
11/08/2010
Second issue after quality review
Project co-funded by the European Commission within the Seven Framework Programme
(2007-2013)
Dissemination Level
Y
PU
Public
PP
Restricted to other programme participants (including the Commission Services)
Restricted to a group specified by the consortium (including the Commission
Services)
Confidential, only for members of the consortium (including the Commission
Services)
RE
CO
Start date of project: 01/06/2009
Instrument: Small or medium-scale focused research project
Thematic priority: Sustainable Surface Transport
Duration: 36 months
EC Contract No. FP7 - 234299
EXECUTIVE SUMMARY
The purpose of this deliverable is to identify the key sensors available to the rail market for use in
measuring parameters that can assist in the maintenance of and the prediction of the residual life
of components. The key sensors are those that can monitor the required parameters but
importantly can withstand the railway environment, giving good reliability and will not result in the
current maintenance costs being transferred from the rail infrastructure to the monitoring system.
The document outlines the key parameters that can be sensed using different sensors. The
applicability of each to the industry is then discussed in its relevance to predictive life and
maintenance. It describes the available sensor technology, their function and application to the
railway environment.
PMI-D-CRS-001-02
Page 2 of 19
11/08/2010
EC Contract No. FP7 - 234299
TABLE OF CONTENTS
Executive Summary ...................................................................................................................... 2
List of Figures ................................................................................ Error! Bookmark not defined.
List of Tables ................................................................................. Error! Bookmark not defined.
1. Introduction ............................................................................................................................... 4
2. Monitoring using Sensors.......................................................................................................... 5
3. Sensing Technology ................................................................................................................. 6
3.1 Position ............................................................................................................................... 6
3.1.1
Linear Voltage Displacement Transducer (LVDT) .................................................. 6
3.1.2
Eddy Current Transducers ..................................................................................... 6
3.2 Speed ................................................................................................................................. 6
3.2.1
Velocity Transducer ............................................................................................... 7
3.3 Acceleration ........................................................................................................................ 7
3.4 Force, Torque and Load Measurement ............................................................................... 7
3.4.1
Electrical Resistance Strain Gauge ........................................................................ 7
3.4.2
Fibre Optic Strain Gauge ....................................................................................... 8
3.4.3
Vibrating Wire Strain Gauge .................................................................................. 8
3.4.4
Mechanical Strain Gauge ....................................................................................... 9
3.4.5
Torque Measurement............................................................................................. 9
3.4.6
Pressure (Stress) ................................................................................................. 10
3.5 Temperature ..................................................................................................................... 10
3.5.1
Thermocouples .................................................................................................... 10
4. Typical Applications of Monitoring ........................................................................................... 11
4.1 Position ............................................................................................................................. 11
4.2 Acceleration ...................................................................................................................... 11
4.3 Strain Gauges ................................................................................................................... 12
4.3.1
Electric Resistance Strain Gauges ....................................................................... 12
4.3.2
Fibre Optic Strain Gauge ..................................................................................... 12
Appendix 1 Summary of Measurements AND sensors ................................................................ 15
5. References ............................................................................................................................. 18
PMI-D-CRS-001-02
Page 3 of 19
11/08/2010
EC Contract No. FP7 - 234299
1. INTRODUCTION
Railways and tramways have many different track components all of which require periodic
inspection, regular maintenance and have a finite life. The aim of work package 5 is to allow
automatic inspection and the ability to predict the residual life of the different track components by
application of sensor technologies.
The track components being investigated include:

Switch blades

Stretcher bars

Fishplated and insulated joints

Expansion joints
The purpose of this document is to identify the key sensors that are currently available to the rail
market for use in measuring parameters, which will assist in the prediction of residual component
life. The key sensors are those which can be used in the environment, will give good reliability
and will not simply result in the current maintenance costs being transferred from the rail
infrastructure to the monitoring system.
The document outlines the key parameters that can be monitoried using different sensor
technology. The applicability of each is then discussed in its relevance to predictive life and
maintenance. The next part investigates available sensor technology, their function and
application to the railway environment.
Finally there is a summary of all the sensor technologies covered giving details of accuracy
repeatability and frequency response.
PMI-D-CRS-001-02
Page 4 of 19
11/08/2010
EC Contract No. FP7 - 234299
2. MONITORING USING SENSORS
Sensors can be used to measure a range of operating conditions for monitoring the duty and
condition of track components. The concept is to use intelligent analysis of the output from
sensors fixed to track components to predict when maintenance is required and the residual life
of those components.
Under normal operating conditions the sensors will produce a “signature tune” it is only when the
operation of the component deviates from this signal that the system highlights that it is starting to
deteriorate and maintenance is required. Such a system reduces and potentially eliminates
manual inspection being replaced by continuous monitoring of the component that highlights
when maintenance is required before a failure occurs. The information provided by the sensors
can also be used to predict the remaining life of the component.
The fundamental measurements that can be made using sensors in their various forms can be
split into the following groups

Position, speed and acceleration

Force, torque, stress, pressure

Temperature

Electrical current/voltage

Material property measurements

Surface profile (wear)
Of these a number are more significance to the monitoring of in service railway equipment.

Position, speed and acceleration

Force and stress

Temperature

Surface profile and wear
The systems for monitoring wear and surface profile are actually specialist developments of the
measurement of position, speed and acceleration and have been well researched and reported
therefore will not be covered in detail. Work is ongoing in WP1 in developing these systems for
tramway and metro systems.
PMI-D-CRS-001-02
Page 5 of 19
11/08/2010
EC Contract No. FP7 - 234299
3. SENSING TECHNOLOGY
3.1 POSITION
A range of sensors are available to determine position and displacement, these include Linear
Voltage Displacement Transducers (LVDT), laser range finders, eddy current sensors, and
capacitance sensors.
3.1.1
Linear Voltage Displacement Transducer (LVDT)
A LVDT Displacement Transducer comprises 3 coils: a primary and two secondaries. The transfer
of current between the primary and the secondaries of the LVDT displacement transducer is
controlled by the position of a magnetic core called an armature. Typically the two transducer
secondaries are connected in opposition. At the central position of the measurement stroke, the
two secondary voltages are equal but because they are connected in opposition the resulting
output from the sensor is zero. As the armature moves away from centre, the result is an increase
in one of the position sensor secondaries and a decrease in the other. This results in an positive
or negative output from the measurement sensor depending on which way the armature has
moved with the magnitude of the output being proportional to the distance moved.
The advantage of the LVDT sensor is that there is no electrical contact across the transducer
position sensing element which means clean data, infinite resolution and a very long life.
3.1.2
Eddy Current Transducers
Eddy current transducers consist of a driver and a probe body. The probe head typically contains
two coils an active coil (main) and a balance coil. This uses the effect of eddy (circular) currents
to sense the proximity of non-magnetic conductive materials. A typical eddy current transducer
contains two coils: an active coil (main coil) and a balance coil. The active coil senses the
presence of a nearby conductive object and the balance coil is used to balance the output bridge
circuit and for temperature compensation
3.2 SPEED
Speed measurement is usually measured using a velocity transducer. Laser technology is
available in the form of laser vibrometers.
PMI-D-CRS-001-02
Page 6 of 19
11/08/2010
EC Contract No. FP7 - 234299
3.2.1
Velocity Transducer
A velocity transducer consists of a fixed cylindrical coil, in which a permanent magnet is
suspended by means of a spring. When the casing is subject to vibration there is relative motion
between the magnet and the coil producing an induced voltage in the coil proportional to the
velocity across the coil.
The advantages of the transducer are that it gives a high signal output and can transmit its signal
over long distances (typically up to 300 m). The disadvantage of the system is that due to the
internal damping forces accuracies are limited to ±5% in the frequency range of 20 to 1500 Hz.
3.3 ACCELERATION
The standard method of sensing acceleration is by use of an accelerometer. An accelerometer
typically consists of a piezoelectric crystal between a mass and a rigid bass. The term
piezoelectric refers to the crystals property of generating an electric charge when it is stressed.
Thus when an accelerometer is subject to vibration perpendicular to its base, inertial forces
caused by acceleration of the mass act on the crystal producing a charge proportional to the
mass’s acceleration. Coupling the crystal to a charge amplifier (internal or external to the
accelerometer) a voltage proportional to acceleration is produced.
Accelerometers give a linear response over a wide frequency range 1 Hz to greater than 5 kHz.
Single and double integration of signals to obtain velocity and displacement respectively is
possible although not advised without the addition of additional high pass filters due to charge
drift issues.
3.4 FORCE, TORQUE AND LOAD MEASUREMENT
The measurement of load, force and torque measurement relies on the use of strain gauges in
their various forms. The strain gauge cannot give an absolute measure, of load, torque and force
but can be built into a measurement system that can be designed and calibrated.
There are various forms of strain gauges including: acoustic, capacitive, inductive, mechanical,
optical, piezo-resistive and semi-conductive.
3.4.1
Electrical Resistance Strain Gauge
The electrical resistance strain gauge can be considered as a mature technology dating back to
the 1930’s. It is formed by a resistance element attached to a backing. The resistance element is
normally in the form of a grid, however for high temperature applications it can be formed from a
wire. The strain gauge must be bonded to the component to be monitored, the bond being a
critical part of the measurement system as it is via this interface that strain is transferred from the
component to the strain gauge.
PMI-D-CRS-001-02
Page 7 of 19
11/08/2010
EC Contract No. FP7 - 234299
The strain in the component can then be measured knowing the initial resistance of the strain
gauge, the gauge factor and the change in resistance due to the applied strain.
The strains measured are typically small (microstrain) with similar small changes in gauge
resistance, these small changes being measured using a Wheatstone bridge and suitable
amplification.
In installations where the principal direction of strain is known a single gauge can be applied
however in most applications the principal strain direction is not known and three gauges must be
applied in a rosette formation where the angles between the three gauges are known, thus
allowing the principal direction to be calculated.
3.4.2
Fibre Optic Strain Gauge
A fibre optic strain gauge consists of a fibre optic with a Bragg grating formed within its core by a
modulation of the refractive index of the fibre. As light is passed through the fibre optic the Bragg
grating reflects light at wavelengths associated with the grating spacing. As the fibre is strained
the spacing of the Bragg grating is changed and hence the wavelength of the reflected light is
changed. By passing a broad spectrum of light and monitoring the frequency of the reflected light
the strain in the fibre can be determined.
A series of Bragg gratings can be formed at discrete positions along the length of the fibre optic.
By selecting the spacing of the gratings appropriately the reflected light from one grating does not
interfere with any other on the same fibre. Therefore a single fibre can be used to measure at a
number of discrete locations.
The limitations of fibre optic strain gauges are the fixed equipment and associated cost of the
optical measuring system and the signal processing required.
The fibre optic strain gauge has similar installation requirements to that of the electrical resistance
strain gauge, it has to be bonded to or embedded within the component to be monitored. It can
only measure in a single direction therefore it also needs to be attached in rosette formation if the
principal stress direction is not known. The sensing elements can be small less than ten
millimetres but the patch to which they have to be attached for protection can be large in
comparison e.g. a hundred millimetres.
The disadvantage of the optical gauge is that the fibre Bragg grating is sensitive to temperature
therefore it is critical to measure temperature at the same time so as to compensate for thermally
induced strains, there are a range of methods that can be employed.
The advantage of the optical gauge method is that a number of fibre Bragg gratings can be
etched into a fibre optic, thus one fibre can be used to measure at a number of discrete locations.
3.4.3
Vibrating Wire Strain Gauge
The vibrating wire strain gauge uses the principle that a tensioned wire, when plucked, vibrates at
a frequency that is proportional to the strain in the wire. The gauge is constructed so that a wire is
held in tension between two fixed points. An electromagnet is used to pluck the wire and measure
PMI-D-CRS-001-02
Page 8 of 19
11/08/2010
EC Contract No. FP7 - 234299
the frequency of vibration. Strain is then calculated by applying calibration factors to the
frequency measurement.
Installation of this type of sensor is normally undertaken in large concrete structures when they
are installed, either directly to any reinforcing cage or directly into the concrete after pouring. As
with other strain gauges the principal stress direction must be known or multiple gauges have to
be used. These type of gauges are not suitable for use in high frequency measurements.
3.4.4
Mechanical Strain Gauge
The mechanical strain gauge commonly referred to as a demountable mechanical strain gauge
(DEMEC) is designed to enable strain measurements to be made at different parts of a structure
using a single instrument. It consists of a dial gauge attached to an Invar metal bar. A fixed
conical point is mounted at one end of the bar, and a moving conical point is mounted on a knife
edge pivot at the opposite end. The pivoting movement of this second conical point is measured
by the gauge giving a reading of strain.
In a typical application pre-drilled stainless steel discs are attached to a structure. To take a
measurement the conical points of the gauge are inserted into the holes in the discs and the
change in reading on the dial gauge from the installed reading can be converted to the strain in
the structure.
The gauge has been designed so that only minor temperature corrections are required for
changes in ambient temperature, and an Invar reference bar is provided for this purpose.
3.4.5
Torque Measurement
The measurement of torque is typically achieved by the application of strain gauges in a particular
arrangement directly on to a component or by the addition of a discrete measurement system.
The main issues associated with torque measurement, not already covered in the section dealing
with strain gauges, is the transmission of data from a rotating component.
The two common methods are by the use of slip rings or by telemetry. The use of slip rings has
advantages in that it allows power to be supplied and the data transmitted continuously but has
the disadvantage that it has components that wear and require maintenance. The use of
telemetry based systems avoid the use of components that wear, but require the transducers to
be powered by batteries or by use of induction. Both alternatives have limitations, batteries have
to be changed at regular intervals, inductively powered systems require small air gaps between
rotor and stator.
PMI-D-CRS-001-02
Page 9 of 19
11/08/2010
EC Contract No. FP7 - 234299
3.4.6
Pressure (Stress)
The monitoring of pressure is normally associated with fluid systems, however in the context of
measurement transducers, the measurement of the pressure between two components whilst
difficult to monitor continuously can be measured.
Pressure measurement between components is typically achieved by placing a pressure
sensitive membrane between the two objects loading the system and then removing the
membrane. Typically the membranes change colour depending on the pressure applied, devices
of this type do not carry out continuous measurements but record the maximum values.
3.5 TEMPERATURE
Temperature measurement for continuous monitoring is normally carried out by using
thermocouples or pyrometers.
3.5.1
Thermocouples
Thermocouples are formed by the junction of two dissimilar metals that produce a potential which
is related to the temperature at which the junction is. All thermocouples are referenced to zero
degrees Celsius, however for practical measurement systems electronic cold junction
compensation is made to compensate for variations in the temperature of the instrumentation
system.
PMI-D-CRS-001-02
Page 10 of 19
11/08/2010
EC Contract No. FP7 - 234299
4. TYPICAL APPLICATIONS OF MONITORING
4.1 POSITION
Measurement of position is typically restricted to knowing if a device or component has reached
an operating position, it is not normally used to determine condition. Typically eddy current or
capacitance sensors are used.
Within the railway environment position sensing is important for the correct operations of
switches. To ensure that the switch is in the correct position a sensor is used, the output from
which is interlocked with the signalling system to confirm that the correct route is set before the
protecting signal can be cleared to allow the train to proceed.
The output from interlocking sensors combined with monitoring of the drive motor parameters has
been used to understand the performance of switches in track to be able to carry out
maintenance when the system is starting to degrade and not when a severe fault has occurred.
Recent research in this area was carried out within WP3.3 of Innotrack (www.innotrack.eu)
4.2 ACCELERATION
Acceleration measurement are routinely used for investigations of both track and wheel condition
and can frequently be associated with noise measurements.
There are many examples of acceleration measurements being used for the identification of
damage resulting from rolling stock defects such as wheel flats and out of round wheels.
Commercial systems are available and in use such as Gotcha® and WheelChex™. Most system
have a significant signal processing component to process the time waveforms, into frequency
spectra, cepstrum and wavelets. The use of cepstrum analysis has been demonstrated to be
particularly useful as it allows the discrimination of wheelflats independently from the presence of
other defects, even when their effects are hidden in globally high acceleration levels due to heavy
rail corrugation. Systems are also available that use acceleration fitted to vehicle or trolleys that
measure the longitudinal profile of the rail to identify the location and severity of corrugation. One
well proven system is Rail Measurement’s Corrugation Analysis Trolley (CAT) and Rail
Corrugation Analyser(RCA) .
Acceleration measurements have also been used to validate numerical predictions on squat
growth by way of field monitoring, measurement and survey. The predictions concern a
postulated squat growth process, the relation between the dynamic contact force and the
corrugation-like wave pattern that often follow squats, the high frequency wheel/rail interaction
related to squats and the influence of tangential force on squat growth. The validated results have
proven the feasibility for detection of early squats by identification of their signature tunes. Show
the necessity to include dynamic wheel/rail interaction in the analysis of squats, and provide
evidence for the relation between squats initiation, growth and rolling stock performance.
PMI-D-CRS-001-02
Page 11 of 19
11/08/2010
EC Contract No. FP7 - 234299
4.3 STRAIN GAUGES
In the following sections the application of electrical resistance strain gauges and Fibre Optic
Strain Gauges is discussed, greater emphasis has been given to the fibre optic gauges, this is the
result of it being a newer technology and is therefore a significant topic for research.
4.3.1
Electric Resistance Strain Gauges
There are few major references to the use of electrical resistance strain gauges in application to
railway systems. This is mainly the result of the electrical resistance strain gauge being seen as a
low cost item and a standard component in engineering investigations and monitoring. The
references mainly focus on them as a tool and a source of data. An example is the
comprehensive track investigations in to Rolling Contact Fatigue(RCF) in the United Kingdom
following the Hatfield derailment. It adopted a practical and scientific approach to understand the
occurrence of RCF and the behaviour of the railway as a system. The objectives of the project
were to monitor a total of 27 stretches of track providing essential information on the development
of RCF cracks under different conditions. At each site, multiple strain gauges were attached in
single and rosette formation to the rail to give data to validate the models.
4.3.2
Fibre Optic Strain Gauge
There are a number of examples of the use of fibre optic strain gauge systems in the railway
industry, these have included: investigations into vehicle/track interaction, pantograph/catenary
interaction, train detection, weight and speed monitoring and infrastructure monitoring
Vehicle/Track Interaction and Track Condition Monitoring
The modal characteristics of the rail and sleepers have been investigated using fibre optic
sensors to allow the identification of signatures that indicate the presence of damage or
defects1,2,3,4. Fibre optic sensors have been used to characterise the dynamic effect of cracks in
pre-stressed concrete sleepers based on their vibration signatures5. Fibre Bragg gratings (FBG)
bonded to the rails have been used to monitor local deformation of the rail in response to the
loading by a passing train6 and to monitor switch arms during transitions7.
In Hong Kong, an optical fibre sensor system is deployed as a structural health monitoring system
on a passenger rail system, with sensors attached to the rail and to the underside of carriages,
measuring temperature and static and dynamic strain at critical locations. The system provides
information on the loading of the passenger cars, deformation of the rails and of the carriages,
temperatures of axles and brakes, and axle vibrations allowing assessment of corrosion and
bearing wear8.
PMI-D-CRS-001-02
Page 12 of 19
11/08/2010
EC Contract No. FP7 - 234299
The detection of wheel flats has been investigated using multimode fibre optic sensors by
monitoring the temporal changes in the speckle pattern at the output of the fibre 9. FBG sensors
mounted on a Maglev guideway have been used to facilitate the determination of local changes in
curvature and vertical deflection in response to the passing vehicle10. The frequency components
within the FBG sensor measurements matched those of an accelerometer for trains passing at
speeds of up to 40km/h, and the deflection and curvatures determined from the measurements
match theoretical predictions.
Pantograph – Catenary Interaction
The measurement of the contact forces between the pantograph and catenary is an application in
which the electromagnetic interference immunity of fibre optic sensors offers a significant
advantage.
Measurement of the dynamic loads in the vertical and horizontal directions between the
pantograph and catenary on a high speed tracks and in mountainous regions has been achieved
using FBG sensors embedded within the composite carbon/aluminium collector strip11.
Integrating FBG sensors into the current collectors was considered to turn the pantograph into a 3
point bending sensor in direct contact with the overhead cable, with a concomitant reduction in
sensitivity of the measurements to inertial forces introduced by the pantograph suspension
structure. Using an interrogation system with a 500 Hz update rate, measurements undertaking
on a TGV duplex train between Paris and Vendome, with a speed of 320 km/h offered a spatial
resolution of better than 20 cm. The FBG measurements allowed the contact forces and current
collector temperature to be computed in real time12
Train Detection, Weight and Speed Monitoring
FBG sensors have been deployed to detect trains13,14, count train axles15,16 and to measure
velocity17, acceleration17 and weight distribution1,17.
An array of FBG sensors installed on a short span railway bridge was found to be capable of onmotion determination of train speed and weight distribution17. The FBG were mounted in a
weldable package that was spot welded to the track. Sensors were configured such that at each
measurement location two FBG were mounted on the track, with one on the neutral axis and the
other displaced vertically from the neutral axis to allow separation of the effects of the track
deformation from the total deflection of the deck. The deflection of the deck was measured
separately using an FBG mounted of the deck surface. From the combination of the
measurements made by the FBG sensors it was possible to determine speed, acceleration and
weight distribution of a passing train17.
PMI-D-CRS-001-02
Page 13 of 19
11/08/2010
EC Contract No. FP7 - 234299
Infrastructure Monitoring
FBG sensors have been widely deployed in the monitoring of civil engineering structures,
including many bridges18 and tunnels19. The Como railway bridge in Australia has been
instrumented with FBG sensors, measuring strain induced by passing trains at a bandwidth of 16
Hz, with a 1με resolution20.
Geotechnical applications include the use of FBG sensors integrated into geosynthetic sheets
used in the reinforcement of railway platform subject to localised sinkholes, making it possible to
accurately measure the strain of the geosynthetic reinforcement and to validate analytical
calculations used in the design of the platform21. The use of both distributed fibre optic sensors
and multiplexed arrays of FBG sensors to monitor the temperature of the permafrost roadbed
temperature in the Qinghai-Tibet railway has been reported22,23.
PMI-D-CRS-001-02
Page 14 of 19
11/08/2010
EC Contract No. FP7 - 234299
APPENDIX 1 SUMMARY OF MEASUREMENTS AND SENSORS
Parameter to be
Measured
Position
Instrumentation
(Velocity)
Advantages
LVDT
Measurement of deflection / Standard piece of instrumentation
movement
Eddy Current
Measurement of small
deflection.
Capacitance
Measurement of small
deflection.
(Displacement)
Speed
Application
High
accuracy
but
requires Distance
measurement
calibration for the environment proportional to size
of
(material)
transducer, small displacements
Laser
Displacement
Measurement
Absolute measurement from a fixed Can
only
measure
point.
perpendicular to a fixed surface
Velocity
Transducer
Constant regardless of frequency
Range limited between 10Hz
and 2KHz
Laser Vibrometer
Non Contact
Measurements are in line with
laser.
Non Contact Measurement
Acceleration
Accelerometer
Measurement of rail or wheel Range >0Hz and 400kHz
vibration
Strain
Electrical
Stress analysis of
PMI-D-CRS-001-02
Disadvantages
Relatively low cost, item common in Preparation of Surface Critical to
Page 15 of 19
31/01/2010
EC Contract No. FP7 - 234299
Parameter to be
Measured
Instrumentation
Advantages
Disadvantages
Resistance Strain components.
Gauges
Sensing element in
manufactured transducers e.g.
load cell
use in a wide range of applications
Fibre Optic Strain Structural Component
Gauges
Monitoring. Electrical Power
Lines
Many sensing elements can be
formed in a single fibre.
Preparation of Surface Critical to
the performance.
Not affected by electromagnetic
interference.
Require specialist equipment to
analyse the data and convert to
a signal suitable for monitoring.
the performance.
Physical protection and water
proofing required.
Interference from electrical
sources
Vibrating Wire
Strain Gauge
Structural Component
Monitoring
Not suitable for high speed
dynamic measurements
DEMEC
Developed by British Cement Minimal Installation Costs.
and Concrete Association
Access required to
measurement location.
Demountable
Mechanical Strain
Gauge
Load
Application
Accuracy requires a skilled
operator
Load Cell
Must be put into the load path
(Typically strain
gauges)
PMI-D-CRS-001-02
Page 16 of 19
31/01/2010
EC Contract No. FP7 - 234299
Parameter to be
Measured
Temperature
Instrumentation
Thermocouple
Application
Advantages
Disadvantages
Standard piece of instrumentation
can be linked to various monitoring
equipment
Table 1: Summary of Measurements and Sensors
PMI-D-CRS-001-02
Page 17 of 19
31/01/2010
EC Contract No. FP7 - 234299
5. REFERENCES
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
17.
18.
19.
Ho, T.K. , Liu, S.Y. , Lee, K.Y. , Ho, Y.T. , Ho, K.H. , Mccusker, A. , Kam, J. , Tam, H.Y. , Ho, S.L., An investigation
of rail condition monitoring by Fibre Bragg Grating sensors, Transactions Hong Kong Institution of Engineers,
16, 9-15, 2009
Ho, T.K.; Liu, S.Y.; Ho, Y.T., Ho, K.H. , Mccusker, A. , Kam, J. , Tam, H.Y. , Ho, S.L., Signature analysis on wheelrail interaction for rail defect detection 4th IET International Conference on Railway Condition Monitoring RCM 2008, UK, 2008.
Topalov, I, Georgieva, M, Investigation of the possibilities for implementation of fibre optic detection of
damaged rails, 31st International Spring Seminar on Electronics Technology (ISSE 2008), 240-242, 2008
Mennella, F; Laudati, A, Esposito, M, Cusano A, Cutolo A, Giordano M, Campopiano S, Breglio G, Railway
monitoring and train tracking by fibre Bragg grating sensors Proc SPIE 6619, H6193-H6193, 2007
Kaewunruen, S; Remennikov, A, Dynamic effect on vibration signatures of cracks in railway prestressed
concrete sleepers Structural Integrity And Failure 41-42, 233-239, 2008.
Mennella, F; Laudati, A; Esposito, M, Cusano, A. , Cutolo, A. , Giordano, M. , Campopiano, S. , Breglio, G.,
Railway monitoring and train tracking by fibre Bragg grating sensors Proc. SPIE 6619, H6193-H6193, 2007.
Laudati, A; Lanza, G; Cusano, A, et al., Railway Monitoring and Train Tracking by Fibre Bragg Grating
Sensors: A Case Study in Italy, Proc. 4th European Workshop on Structural Health Monitoring, Poland, pp
183-189, 2008.
Tam, H.Y. , Liu, S.Y. , Guan, B.O. , Chung, W.H. , Chan, T.H.T. , Cheng, L.K. Utilization of fibre optic Bragg
Grating sensing systems for health monitoring in railway applications, 6th International Workshop on
Structural Health Monitoring, 1 and 2, 1824-1831,2007
Anderson, DR Detecting flat wheels with a fibre-optic sensor Joint Rail Conference on Restoring and
Upgrading Rail Infrastructure, Rolling Stock and Systems, 31, 25-30, 2006
Kang, D. , Chung, W. Integrated monitoring scheme for a maglev guideway using multiplexed FBG sensor
arrays, NDT and E International, 42, 260-266, (2009)
Schröder, K. , Ecke, W. , Kautz, M. , Willett, S. , Tchertoriski, A. , Jenzer, M. , Kaluza, G. Fiber optical sensor
network embedded in a current collector for defect monitoring on railway catenary Proc. SPIE 6585, U203U210, 2007.
Maurin, L; Ferdinand, P; Laffont, G, Roussel N, Boussoir J, Rougeault S., High speed real-time contact
measurements between a smart train pantograph with embedded Fibre Bragg Grating sensors and its
overhead contact line 6th International Workshop on Structural Health Monitoring, 1 and 2 , 1808-1815,
2007
Wang, Y.-H., Jian, S.-S. , Ren, W.-H. , Liu, Y., Tan, Z.-W., Train locating system based on WDM and TDM FBG
series, Journal of Optoelectronics Laser, 19, pp. 1084-1087, (2008)
Wei, Y., Qin, X., Jian, S. Train real-time tracing system based on distributed Fibre Bragg Grating sensors Proc.
SPIE, 6019 II, art. no. 60194I, (2005)
Li, W.-L., Pan, J.-J., Fan, D., Data acquisition and processing for fibre grating train axle counting system
Journal of Wuhan University of Technology, 31, 13-15, 2009
Li, WL; Jiang, N; Liu, JS, Zhang, Y., Train axle counters by Bragg and chirped grating techniques Proc. SPIE,
7004, 70045J-1-4, 2008.
Da Costa Marques Pimentel, R.M. , Barbosa, M.C.B. , Costa, N.M.S. , Ribeiro, D.R.F. , De Almeida Ferreira,
L.A., Araújo, F.M.M. , Calçada, R.A.B., Hybrid fibre-optic/electrical measurement system for characterization
of railway traffic and its effects on a short span bridge IEEE Sensors Journal 8, 1243-1249, 2008
Chung, W; Kang, D, Full-scale test of a concrete box girder using FBG sensing system, Eng.Struct. 30, 643652, 2008.
Fujihashi, K; Kurihara, K; Hirayama, K, Toyoda S., Monitoring system based on optical fiber sensing
technology for tunnel structures and other infrastructure Sensing Issues in Civil Structural Health Monitoring
185-195, 2005
PMI-D-CRS-001-02
Page 18 of 19
31/01/2010
EC Contract No. FP7 - 234299
20. Zhang, J., Sun, W. , Peng, G.D. , Yuan, L., Monitoring the Como Railway Bridge based on dynamic FBG sensor
system Proc. SPIE 6423, art. no. 642329.
21. Villard, P; Briancon, L., Design of geosynthetic reinforcements for platforms subjected to localized sinkholes
Canadian Geotechnical Journal 45, 196-209, 2008.
22. Zhang, W., Dai, J., Sun, B., Du, Y., FBG sensor network in Qinghai-Tibet railway, Proc. SPIE 678439-1-6,
2007.
23. Zhang W., Shi B., Suo W., Cai Y., Wu Q., An experimental study on thermal state monitoring for permafrost
roadbed of Qinghai-Tibet Railway using DTS, 2nd International Conference on Structural Health Monitoring
of Intelligent Infrastructure, 573-576, 2006
PMI-D-CRS-001-02
Page 19 of 19
31/01/2010