[0001] The present invention concerns a method for initializing the Full Supervision mode
for the movement of a train on a railway equipped with a signaling system complying
with the ERTMS/ETCS Level 2 or Level 3 standards, as defined by UNISIG.
[0002] According to the ETCS Level 2 standard, and as illustrated in figure 1, a signaling
system 1 of a railway 2 comprises, on-board each train, such as train 4, an EVC (for
"European Vital Computer"), and, on the ground, in a control center 10, a RBC (for
"Radio Block Centre"), an interlocking system, called IXL, and a supervision system,
called ICC (for "Integrated Control Centre"), and, along the tracks of the railway
2, various trackside equipment connected to object controllers 16.
[0003] In figure 1, an example of trackside equipment is given by the axle counters 30 at
each end of the blocks subdividing the railway 2. A set of axle counters allows the
RBC to determine the occupancy status of the corresponding block, which can take the
value "OCCUPIED" or "NOT OCCUPIED". It is to be noted that the ends of a block, Ai
or Bi in figure 1 (with index i between 1 and 6) are indicated by associated panels.
Another example of trackside equipment is given by point machines PM1 to PM4 for locking
the corresponding point systems either in a straight position or a diverted position.
[0004] A backbone 20 links the objects controller 16 to the control center 10.
[0005] A radio communication infrastructure, for example of the GSM type, referenced by
numeral 22 in figure 1, allows a bidirectional communication between EVCs on board
each trains and the RBC.
[0006] The ICC is in charge of defining a route for a train in order this latter to complete
its mission.
[0007] The IXL is in charge of opening the route in front of the train, according to the
route defined by the ICC. The IXL thus commands the pieces of trackside equipment
to set them in the appropriate position or status.
[0008] The RBC is in charge of supervising the movement of the train, by sending regularly
movement authorities. A movement authority informs the train that it can move safely
forward from its current point to an end point of the movement authority. The movement
authority is determined from the occupancy status of the blocks making up the route
opened in front of the train.
[0009] On reception of the movement authority, the EVC onboard the train calculates speed
curves and brake profiles in order to control the train movement. The train being
completely supervised is said to be in Full Supervision mode, or FS mode.
[0010] Beside the FS mode, the ETCS level 2 defines a Staff Responsible mode, SR mode, and
an on-sight mode, OS mode, in which a train can enter onto a block whose occupancy
status is "OCCUPIED".
[0011] In the SR mode, the driver has to drive the train under his own responsibility, at
a low speed.
[0012] In the OS mode, the driver has to drive the train on-sight at a reduced speed and
the EVC onboard the train controls a few parameters, for example that the train remains
inside the occupied block. The driver is responsible for checking the track occupancy
when moving the train, because the track may be occupied.
[0013] This SR/OS mode is useful in case of anomalies, such as an axle counter not counting
the right number of axles of a passing train so that the RBC considers the corresponding
block as occupied, while it is in fact not occupied. This OS mode is also useful for
train composition, when a locomotive has to enter a block already occupied with coaches
to which this locomotive has to be coupled.
[0014] At start-up of a train, for a new mission, the EVC registers itself to the RBC. But,
before the RBC is capable of sending a first movement authority to the train in order
for it to operate in the FS mode, the RBC has to ensure that there is no other train
or other vehicle between the current position of the train and the end point of the
current block.
[0015] Indeed, the current block being in the occupancy status "OCCUPIED", due to the presence
of the train considered, another train could also be present inside this current block.
In this condition, the RBC cannot send a movement authority including the end of the
current block, while it is capable to send a movement authority once the train has
reached the end point of this current block, knowing that the next block is in the
occupancy state "NOT OCCUPIED". Consequently, the driver has to move the train to
the end of the current block in the SR or OS mode.
[0016] It has also been proposed to send a movement authority for the full supervision of
the train before the train reaches the end point of the current block, when the RBC
can receive a confirmation that the track ahead the train is free as far as the end
of the current block. This information is called TAF information, for Track Ahead
Free.
[0017] Several mechanisms are proposed by UNISIG to guarantee that the track ahead is free:
- In a first mechanism, called TAF request mechanism, and disclosed in the subset 26
version 3.4.0, ยง 5.9.6.2.3 of the ERTMS/ETCS Level 2 standard, the RBC sends a TAF
request to the EVC, which in turn displays this request onto an appropriate screen
in the train driver cabin. If the driver confirms that the track is free up to the
end of the current block, the EVC will transmit this TAF information back to the RBC.
The RBC can then send a movement authority for switching the operative mode of the
EVC into the FS mode, this movement authority extending over the end portion of the
current block and the next block.
- In a second mechanism, the known Automatic TAF solution, proposed by UNISIG in its
ETCS Engineering guidelines (Informative Specification, reference ERA/ERTMS/040054),
can be used in an ATAF mechanism to provide the TAF information without any input
from the driver. This is done through a combination of reported train position and
trackside information.
[0018] But, for both of these mechanisms, it is only possible to guarantee that the track
ahead is free when the train is close enough to the end of the current block (at sighting
distance for the TAF request mechanism, and inside a distance guaranteed as free for
the ATAF mechanism).
[0019] Thus, at the start-up of a train, the practical method is to move the train in SR
or OS mode, from the current point to a point close enough to the end of the current
block so that a TAF request mechanism or an ATAF mechanism be able to compute TAF
information inside the RBC, as recommended in the Start of Mission in Level 2 Guideline
(Informative Specification, reference ERA/ERTMS/040054).
[0020] This is not an optimized solution due to obvious safety and operational reasons,
in particular for blocks of great length where the end point is far away.
[0021] The invention therefore aims at overcoming this problem.
[0022] To this end, the object of the invention is to provide a method as defined by the
claims. With this method, it is possible to start automatically a train in the FS
mode, as defined in ERTMS/ETCS Level 2 or Level 3, even if the train is not close
to the end of the current block.
[0023] The invention and its advantages will be better understood upon reading the description
which will follow, provided solely by way of example with reference made to the accompanying
drawings in which:
- Figure 1 is a general schematic representation of a railway equipped with a ERTMS/ETCS
signaling system; and,
- Figure 2 is a block diagram of the preferred embodiment of the method according to
the invention.
[0024] The principle of the method consists in, as soon as the train of interest (called
the first train in the following) disconnects from the RBC at the end of a mission,
while being located inside a signaling block (called the current block in the following),
monitoring continuously if another train or vehicle (called the second train in the
following) enters or has the possibility to enter into said signaling block, until
the first train connects again to the RBC for a new mission. Then, if the first train
reports a current position compatible with the current block and if no second train
has entered or has had the possibility to enter into the current block, the RBC is
able to send immediately a movement authority to place the first train into the FS
mode, this movement authority extending from the current position of the first train
and covering the end portion of the current block.
[0025] An embodiment of the method according to the invention will now be given in reference
to figure 1 and 2.
[0026] In step 110 of the method 100, the first train 4, supervised according to the FS
mode, enters block A6-A3, corresponding to a platform 40 of a station, and stops along
the platform 40.
[0027] In step 120, to allow other trains to pass the platform 40, the first switch PM1
is set in the deviated position A1-A4, and the second switch PM2 is set in the direct
position A5-A2. Thus, no other train can enter inside the block A6-A3, from A3.
[0028] In step 130, the first train 4 ends its mission. The EVC on board train 4 disconnects
from the RBC, while reporting current position of train 4 inside block A6-A3, which
is then considered as the current block for train 4.
[0029] Immediately, in step 140, the RBC launches a monitoring function of the status of
the current block associated to train 4.
[0030] This function monitors if a second train has the possibility to enter into bloc A6-A3,
from A3.
[0031] This function is based on the periodic verification of at least one logical constraint
about events affecting the railway in the vicinity of the current block A6-A3.
[0032] If the or each logical constraint is verified a TAF attribute of the current block,
maintained by the RBC, keeps the value "FREE", otherwise it takes the value "NOT FREE".
[0033] For example, in step 142, the RCB receives, form the IXL, the positions of the first
and second point machines PM1 and PM2 and the occupancy status of the blocks adjacent
to the current block A6-A3, i.e. blocks A3-A5-A2 and A1-A6-A4.
[0034] In step 143, the RBC checks that logical constraints are still verified.
[0035] If for example, block A3-A5-A2 becomes occupied while the position of the second
point machine PM2 has been modified to its diverted position, A3-A2, it cannot be
guaranteed anymore that the track ahead train 4 is free until A3, as a train may have
entered bloc A6-A3 from A3. In this case, the TAF attribute for current block A6-A3
is set to the value "NOT FREE".
[0036] Once the TAF attribute has the value "NOT FREE", it can only be reinitialized at
the value "FREE" when the occupancy status of the current signaling block A6-A3 becomes
"NOT OCCUPIED", i.e. when the current train and possibly other trains have left the
current block.
[0037] Steps 142 and 143 are repeated at a high frequency, for example every second, until
the EVC of the first train 4 connects again to the RBC.
[0038] In step 150, when the first train 4 performs its start of mission and connects to
the RBC, it sends a position report indicating its current position to the RBC.
[0039] In step 160, the RBC verifies that the position report is valid, i.e. that the first
train 4 having ended its mission in block A6-A3, is starting a new mission from this
same block.
[0040] With a valid position report, in step 170, the RBC read the current value of the
TAF attribute for the current block A6-A3.
[0041] When the current value of the TAF attribute is "FREE", in step 180, the RBC sends
directly a FS movement authority to the first train 4. This FS movement authority
comprises at least the portion of block A6-A3 from the current position of the first
train to the end point of the block A6-A3, and possibly the preferably next block.
[0042] In step 190, on receipt of this FS movement authority, the first train 4 starts its
mission immediately in FS mode.
[0043] If the current value of the TAF attribute is "NOT FREE", it is not possible for the
RBC to guarantee that the first train is alone inside the current signaling block
on which it is stopped. It is not possible for the RBC to send directly a FS motion
authority to the first train 4. A backup procedure 200 using the known TAF request
or ATAF mechanisms is then applied.
[0044] More advanced logical constraints may be checked periodically by the RBC to update
the value of a TAF attribute of the current block associated to a train having ended
its mission. Such advanced constraints may be based on information from the trackside
equipment and/or other information determined by high level systems, like the ICC:
train occupation and localization based on switch position, block occupancy, other
train position reports, train routes management, etc.
[0045] For example, in case the first train is recomposed after the end of its mission,
additional information can be gathered to allow the RBC to know if the first train
is still the only train on the block. For example the information outputted by a train
composition management function realized by the ICC can be taken into account to build
an advanced constraint.
[0046] In another example, in case the first train is split after its mission has ended,
additional information can be obtained from the train integrity management function
available in ETCS Level 3.
[0047] As an alternative, in place of the RBC, other existing systems of the signaling system
1 or a new dedicated monitoring module of the signaling system could realize the monitoring
function described above.
[0048] According to this method, there is no need for the systematic use of TAF request
or ATAF mechanisms at starting up of a train. By monitoring the history of the events
on the track around the block where the train of interest has stopped, from the time
it has stopped to the time it restarts, it is possible to start the next mission immediately
in the ETCS FS mode, wherever the train is located inside the current signaling block
and whatever the length of this current signaling block is.
1. Method (100) for initializing the Full Supervision mode for the movement of a train
(4) on a railway (2) equipped with a signaling system (1) complying with the ERTMS/ETCS
Level 2 or Level 3 standards,
characterized in that it comprises the steps of:
- Identifying the signaling block (A6-A3) in which the train (4) was located when
an Embedded Vital Computer (EVC) on board the train disconnects from a Radio Bloc
Center (RBC) of the signaling system;
- monitoring said signaling block by checking periodically that at least one logical
constraint that no other train enters or can enter in said signaling block (A6-A3)
is verified, the or each logical constraint being elaborated from events on the railway
in the vicinity of said signaling block (A6-A3); and, when the result of the checking
is negative, updating a value of an attribute (TAF) associated with said signaling
block (A6-A3), the attribute (TAF) switching from the value "FREE" to the value "NOT
FREE";
- when the Embedded Vital Computer (EVC) of the train (4) reconnects to the Radio
Bloc Center (RBC) for a new mission, the Radio Bloc Center reads the current value
of the attribute (TAF) and, if said attribute has the value "FREE", sends a movement
authority to the train (4) in order to supervise the movement of the train according
to the Full Supervision mode, at least on said signaling block.
2. Method according to claim 1, wherein the or each logical constraint is elaborated
from data selected in the group comprising switch position, signaling block occupancy,
other train position reports and train route management.
3. Method according to claim 1 or claim 2, wherein the monitoring step is performed by
the Radio Block Center (RBC).
4. Method according to any one of claims 1 to 3, wherein, once the attribute (TAF) has
the value "NOT FREE", the attribute is reinitialized at the value "FREE" when an occupancy
status maintained by the Radio Block Center (RBC) of said signaling block is "NOT
OCCUPIED".
5. Method according to any one of claims 1 to 3, wherein, when the Embedded Vital Computer
(EVC) of the train (4) reconnects to the Radio Bloc Center (RBC) for a new mission,
the Embedded Vital Computer sends a position report of the train (4) and the Radio
Block Center (RBC) checks that the current position of the train (4) mentioned in
the position report is located inside the signaling block (A6-A3) associated to the
train when said train ended its mission, before reading the value of the attribute
(TAF) corresponding to said signaling block (A6-A3).
6. Signaling system (1) complying with the ERTMS/ETCS Level 2 or Level 3 standards, for
the Full Supervision of the movement of the trains circulating on a railway, characterized in that it comprises a monitoring module capable of monitoring a signaling block associated
with a train, which was located on said signaling block when an Embedded Vital Computer
on board the train disconnects from a Radio Bloc Center of the signaling system, by
checking periodically that at least one logical constraint that no other train enters
or can enter in said signaling block is verified, the or each logical constraint being
elaborated from events on the railway in the vicinity of said signaling block, and,
when the result of the checking is negative, by updating a value of a TAF attribute
associated with said signaling block, the TAF attribute switching from the value "FREE"
to the value "NOT FREE", and in that the Radio Block Center is capable of reading the current value of the TAF attribute
when the Embedded Vital Computer of the train reconnects to the Radio Bloc Center
for a new mission, and, if the TAF attribute has the value "FREE", sends a FS movement
authority to the train in order to supervise the movement of the train according to
the Full Supervision mode at least on said signaling block.
7. Signaling system according to claim 6, capable of realizing a method according to
any one of claims 1 to 5.