How to mark the end of a speed restriction? [message #559] |
Thu, 12 June 2014 07:30 |
Christian Rahmig
Messages: 151 Registered: January 2011
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Senior Member |
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Dear railML users,
brought up by Dirk Bräuer from iRFP we discussed the question: How to
model the end of a speed restriction?
The idea was to use the <speedChange> element as follows:
<speedChange id="sc7" pos="256.7" vMax="end" dir="up" />
The problem resulting from this approach relates to the data type that
is used for defining the maximum speed, tSpeed. Currently, it does not
support the mix of numeric values with other entries. A quick solution
can be to define vMax="-1" as the valid expression for the end of a
speed restriction. What is your opinion about this idea?
[1] https://trac.railml.org/ticket/41
Best regards
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Christian Rahmig
railML.infrastructure coordinator
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Re: How to mark the end of a speed restriction? [message #1228 is a reply to message #559] |
Thu, 12 June 2014 23:32 |
Susanne Wunsch railML
Messages: 0 Registered: January 2020
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Hi Christian,
Christian Rahmig <coord(at)infrastructurerailmlorg> writes:
>
> brought up by Dirk Bräuer from iRFP we discussed the question: How to
> model the end of a speed restriction?
> The idea was to use the <speedChange> element as follows:
>
> <speedChange id="sc7" pos="256.7" vMax="end" dir="up" />
>
> The problem resulting from this approach relates to the data type that
> is used for defining the maximum speed, tSpeed. Currently, it does not
> support the mix of numeric values with other entries.
Why not to enhance this type with an xs:union and restricted xs:string
for the xs:enumeration value "end"? It would be the same way, as already
done with "rail:tOtherEnumerationValue".
Kind regards...
Susanne
--
Ingenieurbüro gleisBezug; Susanne Wunsch; +49-351-46927070
Adresse: Schrammsteinstraße 8; 01309 Dresden; Ust-Id: DE273670238
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Re: How to mark the end of a speed restriction? [message #1230 is a reply to message #1229] |
Fri, 20 June 2014 09:03 |
Susanne Wunsch railML
Messages: 0 Registered: January 2020
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Hi Christian,
Christian Rahmig <coord(at)infrastructurerailmlorg> writes:
>
> <xs:simpleType name="tVMax">
> <xs:union>
> <xs:simpleType>
> <xs:restriction base="rail:tSpeedKmPerHour" />
> </xs:simpleType>
> <xs:simpleType>
> <xs:restriction base="xs:string">
> <xs:pattern value="end" />
> </xs:restriction>
> </xs:simpleType>
> </xs:union>
> </xs:simpleType>
>
> The speedChange's attribute @vMax uses this data type.
>
> I hope this solution solves the problem with the undefined maximum
> speed at the end of a temporary speed restriction zone and I
> appreciate your comments about it...
Great!
You have chosen the regular expression option in XML schema. I would
admit, that there is another possibility to define the value "end",
allowing to comment this value:
<xs:enumeration value="end" >
<xs:annotation>
<xs:documentation>The value 'end' should be used for temporary
speed restrictions, otherwise define the next speed aspect.</xs:documentation>
</xs:annotation>
</xs:enumeration>
The railML schemas currently use the regular expression method only in
cases, where there is no XML schema alternative, e.g. constraining the
"other-enumeration-value".
See also http://stackoverflow.com/questions/13974148/pattern-vs-enume ration-in-schema-xml
Kind regards...
Susanne
--
Ingenieurbüro gleisBezug; Susanne Wunsch; +49-351-46927070
Adresse: Schrammsteinstraße 8; 01309 Dresden; Ust-Id: DE273670238
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Re: How to mark the end of a speed restriction? [message #3146 is a reply to message #1231] |
Fri, 20 October 2023 12:28 |
Larissa Zhuchyi
Messages: 49 Registered: November 2022
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Member |
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Dear all
There is a suggestion to deprecate the "end" value of @maxSpeed os <speedSection> in railML3 as it seems to be redundant to linear locations of RailTopoModel. What do you think about this?
In the model of railML2 <speedChange> is a spot element which makes it hard to deal with considering that speed is valid from point A to point B. But then in railML3:
- modelling was improved with the introduction of linear locations of RailTopoModel, i.e. @maxSpeed can be explicitly defined from linearCoordinateBegin to linearCoordinateEnd, or intrinsic ones.
- there is a mechanism to link signals with the beginning and end of a speed section with a corresponding child <refersToBeginOfSpeedSection>
Furthermore, in railML2, this issue (end of a speed restriction) from 2014 seems to intersect with the need for a definition of speed at the beginning or end of a track from 2022 [1].
From what I can see, if the definition of speed change is mandatory at the beginning of a track (let's say not restricted one) and then restriction appears one can probably model an end of a restriction just by defining another change with a value equaling to the beginning. See the example code below.
<speedChange id="111" pos="0" dir="up" profileRef="all" vMax="80" signalised="false">
<speedChange id="222" pos="100" dir="up" profileRef="all" vMax="30" signalised="true"> <!-- begining of speed restriction -->
<speedChange id="333" pos="200" dir="up" profileRef="all" vMax="80" signalised="true"> <!-- end of speed restriction -->
[1] https://development.railml.org/railml/version2/-/issues/425
Larissa Zhuchyi – Ontology Researcher
railML.org (Registry of Associations: VR 5750)
Altplauen 19h; 01187 Dresden; Germany www.railML.org
[Updated on: Fri, 20 October 2023 12:34] Report message to a moderator
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