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[railML 3.2] Speed dependent overlaps [message #3404]

Tue, 03 December 2024 12:14

David Lichti
Messages: 54
Registered: December 2020

Member

Hi IL specialists,

We need to export route overlaps that depend on the speed of the approaching train.

A single route exit signal may have more than one overlap. Each of them can only be used up to a certain permissible speed of the expected train movement on the route. So, this information is important for choosing the appropriate overlap for a route occupation.

How can such a speed information be associated to a railML 3.2 overlap? There is an overlapSpeed attribute. But the documentation says, it relates to other trains than the one using the related route. The releaseSpeed attribute relates to the train control system.

Best regards

David

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Re: [railML 3.2] Speed dependent overlaps [message #3429 is a reply to message #3404]

Mon, 13 January 2025 16:38

Jörg von Lingen
Messages: 115
Registered: March 2016

Senior Member

Hi David,

it took some time to dig into the history of this attribute. It was originally
designed as speedInOverlap with the information "Trains other than the one for
which the route-overlap is locked may be attributed a permitted speed in the
overlap. If the value is set to 0 it is not possible to set a route through the
overlap. Compare this variable with the release speed that applies to the train
that is being released beyond the dangerpoint." It was later renamed in
overlapSpeed.

Thus it seems the attribute overlapSpeed might be used in ETCS context as described.

The speed dependency of the train towards the route exit signal can be modelled
with SignalIL/@approachSpeed where the SignalIL is referenced from routeExit or
destinationPoint via child referTo.

If we need one or more speed values directly in overlap definition please
provide a proposal.

Best regards,
Joerg v. Lingen - Interlocking Coordinator

Am 03.12.2024 um 12:14 schrieb David Lichti:
> Hi IL specialists,
>
> We need to export route overlaps that depend on the speed of
> the approaching train.
>
> A single route exit signal may have more than one overlap.
> Each of them can only be used up to a certain permissible
> speed of the expected train movement on the route. So, this
> information is important for choosing the appropriate
> overlap for a route occupation.
>
> How can such a speed information be associated to a
> https://wiki3.railml.org/wiki/IL:overlap#3.2-0? There is an
> overlapSpeed attribute. But the documentation says, it
> relates to other trains than the one using the related
> route. The releaseSpeed attribute relates to the train
> control system.
>
> Best regards
>
> David

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Re: [railML 3.2] Speed dependent overlaps [message #3434 is a reply to message #3429]

Wed, 15 January 2025 07:53

David Lichti
Messages: 54
Registered: December 2020

Member

Thank you for the digging. It makes that attribute much clearer to me. But it is indeed not suitable for what we need.

The approachSpeed attribute on the signal is not suitable, either: The single signal at the route exit may have multiple overlaps with different approach speeds, each. We rather propose an extension of the IL:Overlap type as follows:

<xs:complexType name="Overlap">
  <xs:complexContent>
    <xs:extension base="rail3:Overlap">
      <xs:attribute name="approachSpeed" type="rail3:tSpeedKmPerHour" use="optional"/>
      <xs:attribute name="staticOccupationExclusionLength" type="rail3:tLengthM" use="optional"/>
    </xs:extension>
  </xs:complexContent>
</xs:complexType>

The approach speed attribute would indicate the maximum speed at which the route exit signal may be approached if this overlap is being used.

The staticOccupationExclusionLength is another attribute that we would need to model overlaps with two sections: In the first section beyond the protected route exit signal, no other occupation is allowed. After a certain distance along the overlap, only dynamic occupations are excluded. That is: Standing vehicles would be allowed in the far end of the overlap, but no train movements.

Best regards

David

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Re: [railML 3.2] Speed dependent overlaps [message #3540 is a reply to message #3434]

Sat, 05 April 2025 16:08

Jörg von Lingen
Messages: 115
Registered: March 2016

Senior Member

Thanks David for your proposal. I will incorporate these two new attributes.

Best regards,
Joerg v. Lingen - Interlocking Coordinator

Am 15.01.2025 um 07:53 schrieb David Lichti:
> Thank you for the digging. It makes that attribute much
> clearer to me. But it is indeed not suitable for what we
> need.
>
> The approachSpeed attribute on the signal is not suitable,
> either: The single signal at the route exit may have
> multiple overlaps with different approach speeds, each. We
> rather propose an extension of the IL:Overlap type as
> follows:
> <xs:complexType name="Overlap">
> <xs:complexContent>
>    <xs:extension base="rail3:Overlap">
>      <xs:attribute name="approachSpeed"
> type="rail3:tSpeedKmPerHour" use="optional"/>
>      <xs:attribute name="staticOccupationExclusionLength"
> type="rail3:tLengthM" use="optional"/>
>    </xs:extension>
> </xs:complexContent>
> </xs:complexType>The approach speed attribute would indicate
> the maximum speed at which the route exit signal may be
> approached if this overlap is being used.
>
> The staticOccupationExclusionLength is another attribute
> that we would need to model overlaps with two sections: In
> the first section beyond the protected route exit signal, no
> other occupation is allowed. After a certain distance along
> the overlap, only dynamic occupations are excluded. That is:
> Standing vehicles would be allowed in the far end of the
> overlap, but no train movements.
>
> Best regards
>
> David

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Re: [railML 3.2] Speed dependent overlaps [message #3836 is a reply to message #3540]

Thu, 11 December 2025 17:32

Marharyta Vyskarka
Messages: 22
Registered: April 2025

Junior Member

Hello everyone,

To keep everything updated, I want to note that the proposed two attributes have been added to Overlap in the railML 3.4 beta [1].

[1] https://development.railml.org/railml/version3/-/tags/3.4-be ta2

Best regards,
Margo Vyskarka

Marharyta Vyskarka – Software Developer
railML.org (Registry of Associations: VR 5750)
Altplauen 19h; 01187 Dresden; Germany www.railML.org

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