[0001] This Invention is related to a wheel sensor monitoring method and to a sensor environment
monitoring method and a to a system executing such a method.
[0002] There are known methods of measurement sensor monitoring, including railway vehicle
wheel sensors and methods of sensor environment monitoring including measurement and
recording of sensor working conditions, such as internal temperature, vibrations inside
the sensor and relationships between electric signals inside the sensor, as well as
conditions in the environment of the sensor, such as ambient temperature and relative
humidity.
[0003] There are also known evaluation systems evaluating information provided by the sensor,
resulting in information about the technical condition of the sensor and about its
working conditions, useful for forecasting the technical condition of the sensor and
for its remaining lifetime.
[0004] There are known evaluation methods used to detect wheel presence and to monitor the
technical condition of the wheel sensor, which independently receive the wheel presence
signal and a signal reflecting technical condition of the sensor.
[0005] This invention is related to development of a solution which ensures quasi-continuous
monitoring that allows to observe working conditions of a wheel sensor. This objective
was achieved through simultaneous sending signals from measurement sensors which detect
the observed parameters and from the wheel sensor to an evaluation system. The system
monitors the wheel sensor and its environment including measurement and recording
of wheel sensor working conditions, it is used to form a set of diagnostic information
variable, which over time is used to create a diagnostic signal that is sent to the
evaluation system. This system also receives the wheel presence signal. It is characterised
in that according to the invention a diagnostic signal and a wheel presence signal
are sent simultaneously and automatically to the evaluation system, in constant or
variable intervals. A frequency band higher than the frequency band used by the wheel
presence signal is used to send the diagnostic signal. Then the diagnostic signal
and the wheel presence signal are added together to form a resulting signal.
[0006] Potential, mutual interference of the diagnostic signal and the wheel presence signal
is eliminated by adding these signals only at times ti, when the frequency band used
by the output signal at time ti is significantly lower, preferably 10 times lower,
than the lower boundary of the frequency band used by the signal at time ti. The resulting
signal is then sent through the current loop to the evaluation system and the resulting
signal is decomposed using top bandwidth filtration and bottom bandwidth filtration.
We thus obtain a separate secondary wheel presence signal, and the secondary diagnostic
signal is sent to the diagnostic module, while the secondary wheel presence signal
is sent to the wheel detection module. The separated signals are then analysed using
a known method. Permitted frequency bands are controlled during the signal adding
operation. If the wheel presence signal exceeds the permitted frequency band, this
is detected on the basis of identification of a momentary wheel presence signal change
that is faster than the momentary signal change corresponding to the permitted frequency
band; this prevents the signals from being added together.
[0007] Preferably, the sensor vibration levels indicating train travel in direct vicinity
of the sensor are also controlled, in order to eliminate interferences during the
signal adding.
[0008] A wheel sensor monitoring system including a wheel detection system, a wheel sensor
interior monitoring system with sensors for, preferably, temperature, vibration, humidity
and a wheel sensor environment monitoring system and an evaluation system is characterised
in that it also Includes a voltage/current conversion system. The wheel detection
system is connected to an input of the voltage/current conversion system through the
first resistor. The wheel sensor interior monitoring system is also connected to an
input of the voltage/current detection system, through the second resistor and through
a converter, preferably a modem.
[0009] The output of the voltage/current conversion system is connected with the top bandwidth
filter system and with the bottom bandwidth filter system. The top bandwidth filter
system is connected with the wheel sensor monitoring evaluation system through a converter,
preferably a modem. The bottom bandwidth filter system is connected with the wheel
detection evaluation system.
[0010] An external wheel sensor environment monitoring system is preferably connected to
the wheel sensor interior monitoring system using a serial interface, preferably using
galvanic separation.
[0011] Use of the invention ensures quasi-continuous monitoring of sensor technical condition,
its working conditions and conditions of its environment in order to forecast the
future technical condition of the sensor, thus improving safety of railway traffic
and the availability of traffic control equipment. Automatically obtained information
can also be used in railway line maintenance based on prevention.
[0012] The invention is better explained using a description of an embodiment and using
a drawing, in which Fig. 1 presents the general diagram of the method and Fig. 2 presents
a general diagram of the system.
Example 1
[0013] As Fig. 2 shows, the wheel sensor monitoring system includes a wheel detection system
UDK, a wheel sensor internal monitoring system UMC and sensors: C
Z1 for temperature measurements, C
Z2 for vibration measurements, C
Zn for humidity measurements and an evaluation system UO.
[0014] The system also includes a voltage/current conversion system KUI with wheel detection
system UDK, which is connected to its input via the first resistor R1, and a wheel
sensor Interior monitoring system UMC connected via the second resistor R2 and via
converter K1 comprising a modem.
[0015] The output of the voltage/current conversion system KUI is connected to the top bandwidth
filter system FGP and the bottom bandwidth filter system FDP. The top bandwidth filter
system FGP is connected with the monitoring evaluation system UM_UO via converter
K2, comprising a modem K2. The bottom bandwidth filter system FDP is connected with
the wheel detection evaluation system UDK_UO.
[0016] Working conditions of the wheel sensor are measured and recorded automatically, in
constant intervals Tdi, using the following sensors: for temperature measurements
C
Z1, for vibration measurements C
Z2 and for humidity measurements C
Zn. The obtained measurement results are used to form a set of diagnostic information
ZDti in the wheel sensor internal monitoring system UMC.
[0017] The set of diagnostic information ZDti is used to form a diagnostic signal SD that
is sent to the evaluation system UO as shown in Fig. 1, with the evaluation system
also receiving the wheel presence signal X from the wheel detection system UDK. The
diagnostic signal SD is sent using a frequency band higher than the frequency band
used to send the wheel presence signal X and the diagnostic signal SD is added to
the wheel presence system X to obtain the resulting signal Y.
[0018] Potential mutual interference of the diagnostic signal SD with the wheel presence
signal X is eliminated in such a way that these signals are added only at times ti,
namely when the frequency band used by the output signal Y at time ti is 10 times
lower than the bottom boundary of the frequency band used by the diagnostic signal
SD.
[0019] The resulting signal Y is sent further using a current loop to the evaluation system
UO, and this resulting signal Y is decomposed using top bandwidth filtration FG and
bottom bandwidth filtration FD.
[0020] We obtain a separate secondary diagnostic signal SD_UO
∼SD and a separate secondary wheel presence signal X_UO
∼X. The secondary diagnostic signal SD_UO
∼SD is sent to the diagnostic module MD and the secondary wheel presence signal X_UO
∼X is sent to the wheel detection module MW.
[0021] The separated signals are further analysed in a known manner and diagnostic information
useful in forecasting of sensor technical condition and its remaining lifetime is
obtained. Additionally, the obtained information may be used to evaluate degradation
of railway infrastructure manifesting through increased vibration levels recorded
in the sensor.
Example 2
[0022] The system is executed as in Example 1 with the exception that an external wheel
sensor environment monitoring system UMZ is connected to the wheel sensor internal
monitoring system UMC which uses a serial interface with galvanic separation. It enables
access to diagnostic information related to the track infrastructure, for example
about increased track temperature, related to technical condition of equipment installed
within the tracks, for example incorrect junction and junction drive operation, as
well as related to the environment of the track infrastructure, as relative humidity
and temperature requiring the junction to be heated. This information does not require
any additional expenses for dedicated transmission infrastructure thanks to the use
of the wheel sensor and its connection with the evaluation system.
1. A wheel sensor monitoring method, and a method of monitoring sensor environment using
measurements and recording of working conditions of the sensors used to form a set
of diagnostic information variable over time, used to form a diagnostic signal sent
to an evaluation system, which also receives a wheel presence signal, characterised in that the evaluation system (UO) receives simultaneously and automatically, in constant
or variable intervals Td(i) the diagnostic signal (SD) and the wheel presence signal
(X) such that the diagnostic signal (SD) is sent using a frequency band higher than
the frequency band used by the wheel presence signal (X), wherein the diagnostic signal
(SD) and the wheel presence signal (X) are added to obtain the resulting signal (Y),
while potential, mutual interferences between the diagnostic signal (SD) and the wheel
presence signal (X) are eliminated such that these signals are added together only
at times ti, when the frequency band used by the output signal (Y) at time ti is significantly
lower, preferably 10 times lower, than the bottom boundary of the frequency band used
by the signal (SD) at time ti, and afterwards the resulting signal (Y) is sent further,
using a current loop, to the evaluation system (UO) and this resulting signal (Y)
is decomposed using bottom bandwidth filtration (FG) and top bandwidth filtration
(FD), obtaining a separate, secondary diagnostic signal (SD_UO∼SD) and a separate, secondary wheel presence signal (X_UO∼X), wherein the secondary diagnostic signal (SD_UO∼X) is sent to the diagnostic module (MD), while the secondary wheel presence signal
(X_UO∼X) is sent to the wheel detection module (MW) and the separated signals are then analysed
using a known method.
2. A wheel sensor monitoring system including a wheel detection system, a wheel sensor
interior monitoring system Including preferably sensors detecting temperature, vibrations,
humidity and a wheel sensor environment monitoring system and an evaluation system,
characterised in that it includes a voltage-current conversion system (KUI) with a wheel detection system
(UDK) connected to its input via the first resistor (R1) and a wheel sensor interior
monitoring system (UMC) connected via the second resistor (R2) and via a converter
(K1), preferably a modem, while the system output (KUI) is connected with the top
bandwidth filter system (FGP) and with the bottom bandwidth filter system (FDP), wherein
the top bandwidth filter system (FGP) is connected with a monitoring evaluation system
(UM_UO) via a converter (K2), preferably a modem, and the bottom bandwidth filter
system (FDP) is connected with a wheel detection evaluation system (UDK_UO).
3. A system according to Claim 2, characterised in that an external wheel environment monitoring system (UMZ) is connected to the wheel sensor
Interior monitoring system (UMC) using a serial interface, preferably using galvanic
separation.