FIELD OF THE INVENTION
[0001] The present invention relates to an electronic determination device for determining
at least one characteristic of a railway resonant circuit.
[0002] The resonant circuit being included in a trackside train protection system and being
configured for transmitting information to an on-board train protection system by
resonating in response to a signal emitted by the on-board train protection system.
[0003] The invention also relates to a trackside train protection system comprising such
a railway resonant circuit and such an electronic determination device, the determination
device being connected between two terminals of the resonant circuit.
[0004] The invention concerns the field of automatic railway protection installations with
a trackside train protection system including several railway resonant circuits intended
to be arranged along a railway track and an on-board train protection system. The
on-board train protection system is embedded on board a railway vehicle and communicates
successively with the railway resonant circuits arranged along the railway track in
order to ensure protection of the railway vehicle.
BACKGROUND OF THE INVENTION
[0005] The railway resonant circuit is for example a PZB magnet, where PZB is the abbreviation
of German expression
Punktförmige ZugBeeinflussung, officially translated as intermittent automatic train running control. The PZB magnet
is also called PZB/INDUSI magnet.
[0006] For example, a train front operating vehicle is equipped with an onboard transmitter
coil, i.e. an antenna, in which superimposed frequencies of 500 Hz, 1000 Hz and 2000
Hz are injected. The railway resonant circuits are installed along the railway track,
for example at specific distance from a signal or speed position of a trackside signaling
system to be protected by the automatic railway protection installation. Each railway
resonant circuit resonates for at least one of the three frequencies (none, 500 Hz,
1000 Hz and 2000 Hz), depending on the information (one information corresponding
to the selection of given frequency) to be transmitted by the trackside train protection
system to the on-board train protection system.
[0007] When the on-board train protection system with the antenna passes over a corresponding
railway resonant circuit, the presence of the resonant circuit is detected by the
on-board train protection system through a change in magnetic flux created via a resonance
frequency of the specific resonant circuit. This activates an appropriate onboard
circuit and triggers whatever action is required based on the location (e.g., an audible/visual
warning, enforced speed limit, or enforced stop by brakes application). The configuration
of the resonant circuit via frequency selection is either permanent or selected by
the trackside signaling system.
[0008] A correct operation of this automatic railway protection installation strongly depends
on the correct resonance frequency defined by the resonant circuit composition. Consequently,
to ensure safety and availability of the installation, the resonant circuit characteristics
(resonance frequencies and quality factor) have to remain within defined tolerances.
[0009] Checking compliance with these tolerances is generally performed by periodical checks
using a dedicated tool. The tool manually operated by an operator performs the measurement
of the resonance frequency and quality factor parameters of the resonant circuit.
Resonant circuits with characteristics outside the allowed limits are replaced.
[0010] Accordingly,
EP 2 810 848 A2 discloses a method for periodically testing a PZB magnet using a specific device
detecting a phase difference between an injected current and a read back voltage.
When the phase difference is at its minimum, the injected frequency is the resonance
frequency of the PZB magnet. Cut-off frequencies are detected similarly by comparing
-45° and +45° signals.
SUMMARY OF THE INVENTION
[0011] However such a method is costly and not optimal.
[0012] A goal of the present invention is therefore to propose an electronic determination
device for determining at least one characteristic of a railway resonant circuit in
a more efficient and less costly manner.
[0013] To this end, the invention relates to an electronic determination device for determining
at least one characteristic of a railway resonant circuit, the resonant circuit being
included in a trackside train protection system and being configured for transmitting
information to an on-board train protection system by resonating in response to a
signal emitted by the on-board train protection system,
the determination device being adapted to be connected between two terminals of the
resonant circuit and comprising:
- an injection module configured for injecting at least one input alternating voltage
between the terminals of the resonant circuit;
- a measuring module configured for measuring at least one resulting voltage between
the terminals of the resonant circuit after injection of a respective input alternating
voltage;
- a determination module configured for determining at least one characteristic of the
resonant circuit from the at least one measured resulting voltage;
- a radio-transmission module for radio-transmitting the at least one determined characteristic
to a remote electronic apparatus.
[0014] Thanks to the invention, the electronic determination device is configured for determining
at least one characteristic of a railway resonant circuit and for automatically radio-transmitting
the at least one determined characteristic to a remote electronic apparatus via the
radio-transmission module.
[0015] Further, the determination of the at least one characteristic of the resonant circuit
is preferably carried out in a transparent manner during time slot(s) where the resonant
circuit is not excited by the antenna of a corresponding on-board train protection
system.
[0016] According to other advantageous aspects of the invention, the determination device
comprises one or more of the following features taken alone or according to all technically
possible combinations:
- the injection module is configured for injecting at least two input alternating voltages
successively between the terminals of the resonant circuit, the measuring module being
configured for measuring successively at least two resulting voltages between the
terminals of the resonant circuit, each one after injection of a respective input
alternating voltage, and the determination module being configured for determining
the at least one characteristic from the at least two measured resulting voltages;
- two characteristics to be determined are a resonance frequency of the resonant circuit
and a half-bandwidth of a frequency response of the resonant circuit and the injection
module is configured for injecting first, second and third input alternating voltages
successively between the terminals of the resonant circuit, the first input alternating
voltage having a first frequency equal to a reference frequency minus a reference
half-bandwidth, the second input alternating voltage having a second frequency equal
to a reference frequency plus a reference half-bandwidth and the third input alternating
voltage having a third frequency equal to the reference frequency, the measuring module
being configured for measuring a first resulting voltage corresponding to the first
input alternating voltage, a second resulting voltage corresponding to the second
input alternating voltage and respectively a third resulting voltage corresponding
to the third input alternating voltage, and the determination module being configured
for determining the resonance frequency from a first difference between the first
resulting voltage and the second resulting voltage and respectively the half-bandwidth
from a second difference between the second resulting voltage and the third resulting
voltage multiplied by a factor, the factor being substantially equal to
- if the first difference is equal to 0 within a first predefined margin of error, the
determined resonance frequency is equal to the reference frequency; if said first
difference is lower than minus the first predefined margin of error, the reference
frequency is increased and the injection module is configured for injecting new first
and second input alternating voltages successively with the increased reference frequency,
the measuring module being configured for measuring corresponding new first and second
resulting voltages, and the determination module being configured for calculating
a new first difference between the new first resulting voltage and the new second
resulting voltage; and if said first difference is greater than the first predefined
margin of error, the reference frequency is decreased and the injection module is
configured for injecting new first and second input alternating voltages successively
with the decreased reference frequency, the measuring module being configured for
measuring corresponding new first and second resulting voltages, and the determination
module being configured for calculating a new first difference between the new first
resulting voltage and the new second resulting voltage;
- if the second difference is equal to 0 within a second predefined margin of error,
the determined half-bandwidth is equal to the reference half-bandwidth; if said second
difference is lower than minus the second predefined margin of error, the reference
half-bandwidth is increased and the injection module is configured for injecting new
second and third input alternating voltages successively with the increased reference
half-bandwidth, the measuring module being configured for measuring corresponding
new second and third resulting voltages, and the determination module being configured
for calculating a new second difference between the new second resulting voltage and
the new third resulting voltage multiplied by the factor; and - if said second difference
is greater than the second predefined margin of error, the reference half-bandwidth
is decreased and the injection module is configured for injecting new second and third
input alternating voltages successively with the decreased reference half-bandwidth,
the measuring module being configured for measuring corresponding new second and third
resulting voltages, and the determination module being configured for calculating
a new second difference between the new second resulting voltage and the new third
resulting voltage multiplied by the factor.
- a characteristic to be determined is a resonance frequency of the resonant circuit
and the injection module is configured for injecting first and second input alternating
voltages successively between the terminals of the resonant circuit, the first input
alternating voltage having a first frequency equal to a reference frequency minus
a predefined delta and the second input alternating voltage having a second frequency
equal to the reference frequency plus the predefined delta, the measuring module being
configured for measuring a first resulting voltage corresponding to the first input
alternating voltage and respectively a second resulting voltage corresponding to the
second input alternating voltage, and the determination module being configured for
determining the resonance frequency from a difference between the first resulting
voltage and the second resulting voltage;
- if the difference is equal to 0 within a predefined margin of error, the determined
resonance frequency is equal to the reference frequency; if said difference is lower
than minus the predefined margin of error, the reference frequency is increased and
the injection module is configured for injecting new first and second input alternating
voltages successively with the increased reference frequency, the measuring module
being configured for measuring corresponding new first and second resulting voltages,
and the determination module being configured for calculating a new difference between
the new first resulting voltage and the new second resulting voltage; and if said
difference is greater than the predefined margin of error, the reference frequency
is decreased and the injection module is configured for injecting new first and second
input alternating voltages successively with the decreased reference frequency, the
measuring module being configured for measuring corresponding new first and second
resulting voltages, and the determination module being configured for calculating
a new difference between the new first resulting voltage and the new second resulting
voltage;
- a characteristic to be determined is a half-bandwidth of a frequency response of the
resonant circuit and the injection module is configured for injecting former and latter
input alternating voltages successively between the terminals of the resonant circuit,
the former input alternating voltage having a former frequency equal to a predefined
frequency plus a reference half-bandwidth and the latter input alternating voltage
having a latter frequency equal to the predefined frequency, the measuring module
being configured for measuring a former resulting voltage corresponding to the former
input alternating voltage and respectively a latter resulting voltage corresponding
to the latter input alternating voltage, and the determination module being configured
for determining the half-bandwidth from a difference between the former resulting
voltage and the latter resulting voltage multiplied by a factor, the factor being
substantially equal to
- if the difference is equal to 0 within a predefined margin of error, the determined
half-bandwidth is equal to the reference half-bandwidth; if said difference is lower
than minus the predefined margin of error, the reference half-bandwidth is increased
and the injection module is configured for injecting new former and latter input alternating
voltages successively with the increased reference half-bandwidth, the measuring module
being configured for measuring corresponding new former and latter resulting voltages,
and the determination module being configured for calculating a new difference between
the new former resulting voltage and the new latter resulting voltage multiplied by
the factor; and if said difference is greater than the predefined margin of error,
the reference half-bandwidth is decreased and the injection module is configured for
injecting new former and latter input alternating voltages successively with the decreased
reference half-bandwidth, the measuring module being configured for measuring corresponding
new former and latter resulting voltages, and the determination module being configured
for calculating a new difference between the new former resulting voltage and the
new latter resulting voltage multiplied by the factor; and
- the determination device is configured for being permanently connected between the
terminals of the resonant circuit.
[0017] The invention also relates to a trackside train protection system comprising:
- a railway resonant circuit, the resonant circuit being configured for transmitting
information to an on-board train protection system by resonating in response to a
signal emitted by the on-board train protection system; and
- an electronic determination device for determining at least one characteristic the
resonant circuit, the determination device being connected between two terminals of
the resonant circuit, wherein the determination device is as defined above.
[0018] According to another advantageous aspect of the invention, the trackside train protection
system comprises the following feature:
- the resonant circuit has a resonance frequency and includes at least a component among
a capacitor and a coil.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] The invention will be better understood upon reading of the following description,
which is given solely by way of example and with reference to the appended drawings,
in which:
- Figure 1 is a schematic view of a trackside train protection system according to the
invention, comprising a railway resonant circuit, the resonant circuit being configured
for transmitting information to an on-board train protection system by resonating
in response to a signal emitted by the on-board train protection system, and an electronic
determination device for determining at least one characteristic of a resonant circuit,
the determination device being connected between two terminals of the resonant circuit;
- Figure 2 is a curve representing a frequency response of the resonant circuit of Figure
1 and illustrating the calculation of a first difference for determining a resonance
frequency of said resonant circuit; and
- Figure 3 is a view similar to the view of Figure 2 and illustrating the calculation
of a second difference for determining a half-bandwidth of a frequency response of
said resonant circuit.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0020] In the following, the expression "substantially equal to" defines an equality relation
to more or less 10%.
[0021] In Figure 1, a trackside train protection system 10 comprises a railway resonant
circuit 12, the resonant circuit 12 being configured for transmitting information
to an on-board train protection system, not shown, by resonating in response to a
signal emitted by the on-board train protection system.
[0022] The trackside train protection system 10 comprises an electronic determination device
14 for determining at least one characteristic of the resonant circuit 12, the determination
device 14 being connected between two terminals 16 of the resonant circuit 12.
[0023] The resonant circuit 12 has a resonance frequency F
0 and a half-bandwidth df
0 of its frequency response. The resonant circuit 12 has therefore a quality factor
Q verifying the following equation:
where F0 represents the resonance frequency, and
df0 represents the half-bandwidth of the frequency response of the resonant circuit 12.
[0024] The resonance frequency F
0 is for example a frequency substantially equal to one of the following frequencies:
500 Hz, 1000 Hz and 2000 Hz.
[0025] The resonant circuit 12 includes at least a component among a capacitor 18 and a
coil 20. In the example of Figure 1, the resonant circuit 12 includes both the capacitor
18 and the coil 20, and also a resistor 22, each one of the capacitor 18, the coil
20 and the resistor 22 being connected in parallel.
[0026] The determination device 14 is adapted to be connected between two terminals 16 of
the resonant circuit 12 and comprises an injection module 24 configured for injecting
at least one input alternating voltage Vg between the terminals 16 of the resonant
circuit 12 and a measuring module 26 configured for measuring at least one resulting
voltage V
PZB between the terminals 16 of the resonant circuit 12 after injection of a respective
input alternating voltage Vg.
[0027] The determination device 14 also comprises a determination module 28 configured for
determining at least one characteristic F
0, df
0 of the resonant circuit 12 from the at least one measured resulting voltage V
PZB and a radio-transmission module 30 for radio-transmitting the at least one determined
characteristic F
0, df
0 to a remote electronic apparatus 32.
[0028] In the example of Figure 1, the determination device 14 also comprises a measure
resistor 34 connected to the injection module 24 and being intended to be connected
to one of the terminals 16 of the resonant circuit 12.
[0029] The determination device 14 is preferably configured for being permanently connected
between the two terminals 16 of the resonant circuit 12.
[0030] In the example of Figure 1, the injection module 24 is an alternating voltage source
and the measuring module 26 is an alternating voltmeter.
[0031] In the example of Figure 1, the injection module 24, the measuring module 26, the
determination module 28 and the radio-transmission module 30 are respective electronic
modules.
[0032] The injection module 24 is for example configured for injecting at least two input
alternating voltages Vg
1, Vg
2 successively between the terminals 16 of the resonant circuit 12. The measuring module
26 is accordingly configured for measuring successively at least two resulting voltages
V
PZB1, V
PZB2 between the terminals 16 of the resonant circuit 12, each one after injection of
a respective input alternating voltage Vg
1, Vg
2, and the determination module 28 is configured for determining the at least one characteristic
F
0, df
0 from the at least two measured resulting voltages V
PZB1, V
PZB2.
[0033] The injection module 24 is for example configured for injecting a voltage Vg with
amplitude substantially equal to 20 V and a current substantially equal to 100 µA.
Vg is a general notation for the voltage injected by the injection module 24; first,
second and third alternating voltages injected by the injection module 24 with specific
first, second and third frequencies F
1, F
2 and F
3 are further denoted Vg
1, Vg
2 and respectively Vg
3.
[0034] The determination module 28 is linked via respective data links to the injection
module 24, to the measuring module 26 and respectively to the radio-transmission module
30, as shown in Figure 1.
[0035] The radio-transmission module 30 is preferably a low-power radio-transmission module
and is for example compliant with at least one of the following standards: SigFox,
LoRa, Meshed Bluetooth 5.
[0036] The value of the measure resistor 34 is much higher than an impedance Z of the resonant
circuit 12 so as avoiding disturbing the operation of the resonant circuit 12 when
resonating in response to a signal emitted by the on-board train protection system.
The value of the measure resistor 34 is for example substantially equal to 200 kΩ.
[0037] In a first embodiment, two characteristics of the resonant circuit 12 are determined
by the determination device 14: the resonance frequency F
0 and the half-bandwidth df
0 of a frequency response of the resonant circuit 12, shown in Figures 2 and 3 with
the curve 100.
[0038] According to this first embodiment, the injection module 24 is configured for injecting
first Vg
1, second Vg
2 and third Vg
3 input alternating voltages successively between the terminals 16 of the resonant
circuit 12, the first input alternating voltage Vg
1 having a first frequency F
1 equal to a reference frequency F
m minus a reference half-bandwidth df, the second input alternating voltage Vg
2 having a second frequency F
2 equal to a reference frequency F
m plus a reference half-bandwidth df and the third input alternating voltage Vg
3 having a third frequency F
3 equal to the reference frequency F
m.
[0039] The first, second and third frequencies F
1, F
2, F
3 therefore follow respectively the following equations:
[0040] The measuring module 26 is configured for measuring a first resulting voltage V
PZB(F
1), i.e. V
PZB(F
m-df), corresponding to the first input alternating voltage Vg
1, a second resulting voltage V
PZB(F
2), i.e. V
PZB(F
m+df), corresponding to the second input alternating voltage Vg
2 and respectively a third resulting voltage V
PZB(F
3), i.e. V
PZB(F
m), corresponding to the third input alternating voltage Vg
3.
[0041] Further, the determination module 28 is configured for determining the resonance
frequency F
0 from a first difference α between the first resulting voltage V
PZB(F
1) and the second resulting voltage V
PZB(F
2), and respectively the half-bandwidth df from a second difference β between the second
resulting voltage V
PZB(F
2) and the third resulting voltage V
PZB(F
3) multiplied by a factor K, the factor K being substantially equal to
[0042] The first and second differences α, β therefore follow respectively the following
equations:
[0043] Then, if the first difference α is equal to 0 within a first predefined margin of
error ε
1, the determined resonance frequency F
0 is equal to the reference frequency F
m. The value of first predefined margin of error ε
1 is for example substantially equal to 50 mV, or preferably substantially equal to
20 mV.
[0044] If said first difference α is lower than minus the first predefined margin of error
ε
1, the reference frequency F
m is increased and the injection module 24 is configured for injecting new first and
second input alternating voltages Vg
1, Vg
2 successively with the increased reference frequency, and the measuring module 26
is further configured for measuring corresponding new first and second resulting voltages
V
PZB(F
1), V
PZB(F
2). Then, the determination module 28 is configured for calculating a new first difference
α between the new first resulting voltage V
PZB(F
1) and the new second resulting voltage V
PZB(F
2).
[0045] If said first difference α is greater than the first predefined margin of error ε
1, the reference frequency F
m is decreased and the injection module 24 is configured for injecting new first and
second input alternating voltages Vg
1, Vg
2 successively with the decreased reference frequency F
m, and the measuring module 26 is further configured for measuring corresponding new
first and second resulting voltages V
PZB(F
1), V
PZB(F
2). The determination module 28 is then configured for calculating a new first difference
α between the new first resulting voltage V
PZB(F
1) and the new second resulting voltage.
[0046] If the second difference β is equal to 0 within a second predefined margin of error
ε
2, the determined half-bandwidth is equal to the reference half-bandwidth df. The value
of second predefined margin of error ε
2 is for example substantially equal to 50 mV, or preferably substantially equal to
20 mV.
[0047] If said second difference β is lower than minus the second predefined margin of error
ε
2, the reference half-bandwidth df is increased and the injection module 24 is configured
for injecting new second and third input alternating voltages successively with the
increased reference half-bandwidth df, the measuring module 26 being configured for
measuring corresponding new second and third resulting voltages, and the determination
module 28 being configured for calculating a new second difference β between the new
second resulting voltage V
PZB(F
2) and the new third resulting voltage V
PZB(F
3) multiplied by the factor K.
[0048] If said second difference β is greater than the second predefined margin of error
ε
2, the reference half-bandwidth df is decreased and the injection module 24 is configured
for injecting new second and third input alternating voltages successively with the
decreased reference half-bandwidth df, the measuring module 26 being configured for
measuring corresponding new second and third resulting voltages, and the determination
module 28 being configured for calculating a new second difference β between the new
second resulting voltage V
PZB(F
2) and the new third resulting voltage V
PZB(F
3) multiplied by the factor K.
[0049] In other words, in this first embodiment, the injection module 24 is configured for
injecting new input alternating voltages in a next analysis cycle according to the
following rules:
- if α > ε1, then the reference frequency Fm is reduced for the next analysis cycle;
- if α < - ε1, then the reference frequency Fm is increased for the next analysis cycle;
- if β > ε2, then the reference half-bandwidth df is reduced for the next analysis cycle; and
- if β < - ε2, then the reference half-bandwidth df is increased for the next analysis cycle.
[0050] Thus, after one or several analysis cycles, the first and the second differences
α, β respectively converge progressively to the null value and the resonance frequency
F
0 and the half-bandwidth df
0 are then determined by the determination module 28. Further, the quality factor Q
is also calculated according to equation (1).
[0051] Therefore, the determination device 14 allows continuous monitoring of the characteristics
F
0 and Q of the resonant circuit 12, such as the PZB magnet, and this continuous monitoring
is performed in parallel of the resonant circuit state acquisition by the on-board
train protection system.
[0052] The monitoring of the resonant circuit 12, such as the PZB magnet, is performed during
a given time slot where an alternating voltage V
g with a selectable frequency can be generated by the injection module 24 without impact
on the resonant circuit state acquisition.
[0053] In a second embodiment, the characteristic of the resonant circuit 12 to be determined
by the determination device 14 is the resonance frequency F
0.
[0054] According to this second embodiment, the injection module 24 is configured for injecting
first and second input alternating voltages successively between the terminals 16
of the resonant circuit 12, the first input alternating voltage having a first frequency
equal to a reference frequency minus a predefined delta and the second input alternating
voltage having a second frequency equal to the reference frequency plus the predefined
delta, the measuring module 26 being configured for measuring a first resulting voltage
V
PZB(F
1) corresponding to the first input alternating voltage and respectively a second resulting
voltage V
PZB(F
2) corresponding to the second input alternating voltage, and the determination module
28 being configured for determining the resonance frequency F
0 from a difference α between the first resulting voltage V
PZB(F
1) and the second resulting voltage.
[0055] Then, if the difference α is equal to 0 within a predefined margin of error ε
1, the determined resonance frequency F
0 is equal to the reference frequency.
[0056] If said difference α is lower than minus the predefined margin of error ε
1, the reference frequency is increased and the injection module 24 is configured for
injecting new first and second input alternating voltages successively with the increased
reference frequency, the measuring module 26 being configured for measuring corresponding
new first and second resulting voltages V
PZB(F
1), V
PZB(F
2), and the determination module 28 being configured for calculating a new difference
α between the new first resulting voltage V
PZB(F
1) and the new second resulting voltage.
[0057] If said difference α is greater than the predefined margin of error ε
1, the reference frequency is decreased and the injection module 24 is configured for
injecting new first and second input alternating voltages successively with the decreased
reference frequency, the measuring module 26 being configured for measuring corresponding
new first and second resulting voltages V
PZB(F
1), V
PZB(F
2), and the determination module 28 being configured for calculating a new difference
α between the new first resulting voltage V
PZB(F
1) and the new second resulting voltage V
PZB(F
2).
[0058] In other words, in this second embodiment, the injection module 24 is configured
for injecting new input alternating voltages in a next analysis cycle according to
the following rules:
- if α > ε1, then the reference frequency Fm is reduced for the next analysis cycle; and
- if α < - ε1, then the reference frequency Fm is increased for the next analysis cycle.
[0059] In a third embodiment, the characteristic of the resonant circuit 12 to be determined
by the determination device 14 is the half-bandwidth df
0 of the frequency response of the resonant circuit 12 (curve 100 in Figures 2 and
3).
[0060] According to this third embodiment, the injection module 24 is configured for injecting
former and latter input alternating voltages successively between the terminals 16
of the resonant circuit 12, the former input alternating voltage having a former frequency
equal to a predefined frequency plus a reference half-bandwidth df and the latter
input alternating voltage having a latter frequency equal to the predefined frequency,
the measuring module 26 being configured for measuring a former resulting voltage
V
PZB(F
2) corresponding to the former input alternating voltage and respectively a latter
resulting voltage V
PZB(F
3) corresponding to the latter input alternating voltage, and the determination module
28 being configured for determining the half-bandwidth df from a difference β between
the former resulting voltage V
PZB(F
2) and the latter resulting voltage V
PZB(F
3) multiplied by a factor K, the factor K being substantially equal to
[0061] Then, if the difference β is equal to 0 within a predefined margin of error ε
2, the determined half-bandwidth is equal to the reference half-bandwidth df.
[0062] If said difference β is lower than minus the predefined margin of error ε
2, the reference half-bandwidth df is increased and the injection module 24 is configured
for injecting new former and latter input alternating voltages successively with the
increased reference half-bandwidth df, the measuring module 26 being configured for
measuring corresponding new former and latter resulting voltages, and the determination
module 28 being configured for calculating a new difference β between the new former
resulting voltage V
PZB(F
2) and the new latter resulting voltage V
PZB(F
3) multiplied by the factor K.
[0063] If said difference β is greater than the predefined margin of error ε
2, the reference half-bandwidth df is decreased and the injection module 24 is configured
for injecting new former and latter input alternating voltages successively with the
decreased reference half-bandwidth df, the measuring module 26 being configured for
measuring corresponding new former and latter resulting voltages, and the determination
module 28 being configured for calculating a new difference β between the new former
resulting voltage V
PZB(F
2) and the new latter resulting voltage V
PZB(F
3) multiplied by the factor K.
[0064] In other words, in this third embodiment, the injection module 24 is configured for
injecting new input alternating voltages in a next analysis cycle according to the
following rules:
- if β > ε2, then the reference half-bandwidth df is reduced for the next analysis cycle; and
- if β < - ε2, then the reference half-bandwidth df is increased for the next analysis cycle.
[0065] The determination device 14 according to the invention therefore allows determining
at least one characteristic of a railway resonant circuit 12 in a more efficient and
less costly manner.
1. An electronic determination device (14) for determining at least one characteristic
(F
0, df
0, Q) of a railway resonant circuit (12), the resonant circuit (12) being included
in a trackside train protection system and being configured for transmitting information
to an on-board train protection system by resonating in response to a signal emitted
by the on-board train protection system,
the determination device (14) being adapted to be connected between two terminals
(16) of the resonant circuit (12) and comprising:
- an injection module (24) configured for injecting at least one input alternating
voltage between the terminals (16) of the resonant circuit (12);
- a measuring module (26) configured for measuring at least one resulting voltage
between the terminals (16) of the resonant circuit (12) after injection of a respective
input alternating voltage;
- a determination module (28) configured for determining at least one characteristic
(F0, df0, Q) of the resonant circuit (12) from the at least one measured resulting voltage;
- a radio-transmission module (30) for radio-transmitting the at least one determined
characteristic (F0, df0, Q) to a remote electronic apparatus.
2. The determination device (14) according to claim 1, wherein the injection module (24)
is configured for injecting at least two input alternating voltages successively between
the terminals (16) of the resonant circuit (12), the measuring module (26) being configured
for measuring successively at least two resulting voltages between the terminals (16)
of the resonant circuit (12), each one after injection of a respective input alternating
voltage, and the determination module (28) being configured for determining the at
least one characteristic (F0, df0) from the at least two measured resulting voltages.
3. The determination device (14) according to claim 2, wherein two characteristics to
be determined are a resonance frequency (F
0) of the resonant circuit (12) and a half-bandwidth (df
0) of a frequency response of the resonant circuit (12) and the injection module (24)
is configured for injecting first, second and third input alternating voltages successively
between the terminals (16) of the resonant circuit (12), the first input alternating
voltage having a first frequency equal to a reference frequency minus a reference
half-bandwidth (df), the second input alternating voltage having a second frequency
equal to a reference frequency plus a reference half-bandwidth (df) and the third
input alternating voltage having a third frequency equal to the reference frequency,
the measuring module (26) being configured for measuring a first resulting voltage
(V
PZB(F
1)) corresponding to the first input alternating voltage, a second resulting voltage
(V
PZB(F
2)) corresponding to the second input alternating voltage and respectively a third
resulting voltage (V
PZB(F
3)) corresponding to the third input alternating voltage, and the determination module
(28) being configured for determining the resonance frequency (F
0) from a first difference (α) between the first resulting voltage (V
PZB(F
1)) and the second resulting voltage (V
PZB(F
2)) and respectively the half-bandwidth (df) from a second difference (β) between the
second resulting voltage (V
PZB(F
2)) and the third resulting voltage (V
PZB(F
3)) multiplied by a factor (K), the factor (K) being substantially equal to
4. The determination device (14) according to claim 3, wherein:
- if the first difference (α) is equal to 0 within a first predefined margin of error
(ε1), the determined resonance frequency (F0) is equal to the reference frequency;
- if said first difference (α) is lower than minus the first predefined margin of
error (ε1), the reference frequency is increased and the injection module (24) is configured
for injecting new first and second input alternating voltages successively with the
increased reference frequency, the measuring module (26) being configured for measuring
corresponding new first and second resulting voltages (VPZB(F1), VPZB(F2)), and the determination module (28) being configured for calculating a new first
difference (α) between the new first resulting voltage (VPZB(F1)) and the new second resulting voltage; and
- if said first difference (α) is greater than the first predefined margin of error
(ε1), the reference frequency is decreased and the injection module (24) is configured
for injecting new first and second input alternating voltages successively with the
decreased reference frequency, the measuring module (26) being configured for measuring
corresponding new first and second resulting voltages (VPZB(F1), VPZB(F2)), and the determination module (28) being configured for calculating a new first
difference (α) between the new first resulting voltage (VPZB(F1)) and the new second resulting voltage.
5. The determination device (14) according to claim 3 or 4, wherein:
- if the second difference (β) is equal to 0 within a second predefined margin of
error (ε2), the determined half-bandwidth is equal to the reference half-bandwidth (df);
- if said second difference (β) is lower than minus the second predefined margin of
error (ε2), the reference half-bandwidth (df) is increased and the injection module (24) is
configured for injecting new second and third input alternating voltages successively
with the increased reference half-bandwidth (df), the measuring module (26) being
configured for measuring corresponding new second and third resulting voltages, and
the determination module (28) being configured for calculating a new second difference
(β) between the new second resulting voltage (VPZB(F2)) and the new third resulting voltage (VPZB(F3)) multiplied by the factor (K); and
- if said second difference (β) is greater than the second predefined margin of error
(ε2), the reference half-bandwidth (df) is decreased and the injection module (24) is
configured for injecting new second and third input alternating voltages successively
with the decreased reference half-bandwidth (df), the measuring module (26) being
configured for measuring corresponding new second and third resulting voltages, and
the determination module (28) being configured for calculating a new second difference
(β) between the new second resulting voltage (VPZB(F2)) and the new third resulting voltage (VPZB(F3)) multiplied by the factor (K).
6. The determination device (14) according to claim 2, wherein a characteristic to be
determined is a resonance frequency (F0) of the resonant circuit (12) and the injection module (24) is configured for injecting
first and second input alternating voltages successively between the terminals (16)
of the resonant circuit (12), the first input alternating voltage having a first frequency
equal to a reference frequency minus a predefined delta and the second input alternating
voltage having a second frequency equal to the reference frequency plus the predefined
delta, the measuring module (26) being configured for measuring a first resulting
voltage (VPZB(F1)) corresponding to the first input alternating voltage and respectively a second
resulting voltage (VPZB(F2)) corresponding to the second input alternating voltage, and the determination module
(28) being configured for determining the resonance frequency (F0) from a difference (α) between the first resulting voltage (VPZB(F1)) and the second resulting voltage.
7. The determination device (14) according to claim 6, wherein:
- if the difference (α) is equal to 0 within a predefined margin of error (ε1), the determined resonance frequency (F0) is equal to the reference frequency;
- if said difference (α) is lower than minus the predefined margin of error (ε1), the reference frequency is increased and the injection module (24) is configured
for injecting new first and second input alternating voltages successively with the
increased reference frequency, the measuring module (26) being configured for measuring
corresponding new first and second resulting voltages (VPZB(F1), VPZB(F2)), and the determination module (28) being configured for calculating a new difference
(α) between the new first resulting voltage (VPZB(F1)) and the new second resulting voltage; and
- if said difference (α) is greater than the predefined margin of error (ε1), the reference frequency is decreased and the injection module (24) is configured
for injecting new first and second input alternating voltages successively with the
decreased reference frequency, the measuring module (26) being configured for measuring
corresponding new first and second resulting voltages (VPZB(F1), VPZB(F2)), and the determination module (28) being configured for calculating a new difference
(α) between the new first resulting voltage (VPZB(F1)) and the new second resulting voltage (VPZB(F2)).
8. The determination device (14) according to claim 2, wherein a characteristic to be
determined is a half-bandwidth (df
0) of a frequency response of the resonant circuit (12) and the injection module (24)
is configured for injecting former and latter input alternating voltages successively
between the terminals (16) of the resonant circuit (12), the former input alternating
voltage having a former frequency equal to a predefined frequency plus a reference
half-bandwidth (df) and the latter input alternating voltage having a latter frequency
equal to the predefined frequency, the measuring module (26) being configured for
measuring a former resulting voltage (V
PZB(F
2)) corresponding to the former input alternating voltage and respectively a latter
resulting voltage (V
PZB(F
3)) corresponding to the latter input alternating voltage, and the determination module
(28) being configured for determining the half-bandwidth (df) from a difference (β)
between the former resulting voltage (V
PZB(F
2)) and the latter resulting voltage (V
PZB(F
3)) multiplied by a factor (K), the factor (K) being substantially equal to
9. The determination device (14) according to claim 8, wherein:
- if the difference (β) is equal to 0 within a predefined margin of error (ε2), the determined half-bandwidth is equal to the reference half-bandwidth (df);
- if said difference (β) is lower than minus the predefined margin of error (ε2), the reference half-bandwidth (df) is increased and the injection module (24) is
configured for injecting new former and latter input alternating voltages successively
with the increased reference half-bandwidth (df), the measuring module (26) being
configured for measuring corresponding new former and latter resulting voltages, and
the determination module (28) being configured for calculating a new difference (β)
between the new former resulting voltage (VPZB(F2)) and the new latter resulting voltage (VPZB(F3)) multiplied by the factor (K); and
- if said difference (β) is greater than the predefined margin of error (ε2), the reference half-bandwidth (df) is decreased and the injection module (24) is
configured for injecting new former and latter input alternating voltages successively
with the decreased reference half-bandwidth (df), the measuring module (26) being
configured for measuring corresponding new former and latter resulting voltages, and
the determination module (28) being configured for calculating a new difference (β)
between the new former resulting voltage (VPZB(F2)) and the new latter resulting voltage (VPZB(F3)) multiplied by the factor (K).
10. The determination device (14) according to any one of the preceding claims, wherein
the determination device (14) is configured for being permanently connected between
the terminals (16) of the resonant circuit (12).
11. A trackside train protection system (10) comprising:
- a railway resonant circuit (12), the resonant circuit (12) being configured for
transmitting information to an on-board train protection system by resonating in response
to a signal emitted by the on-board train protection system; and
- an electronic determination device (14) for determining at least one characteristic
(F0, df0, Q) the resonant circuit (12), the determination device (14) being connected between
two terminals (16) of the resonant circuit (12),
wherein the determination device (14) is according to any one of the preceding claims.
12. The trackside train protection system (10) according to claim 11 wherein the resonant
circuit (12) has a resonance frequency (F0) and includes at least a component among a capacitor (24) and a coil (26).