Train system requirments, some help neeed.

Hi,

Recently Open BVE ( a popular train-sim) was updated, and one of the features is the ability to provide external .NET plugins to implement simualtion of on-train systems (like TPWS for examaple).

With this in mind I was going to ask someone that develops for Open BVE to develop a plugin for the systems on a 'fictional' 2004 tube stock.

However, before doing that, I needed to write some rough requirements for what the on-board systems needed to do... What follows at the end of this post is the start of my attempts to draft some.

I appreciate that compared to formalised engineering requirements they are laughable, but some feedback would be appreciated.

Posted to trains rather than simulation because it relates to train systems more than simulation at present

Alex Farlie

Onboard Train systems for fictional 2004 tube stock.

-- 1. Critical ATP (Automated train protection) system --

i) The ATP critical system shall monitor train speeds and braking such that it shall be possible to brake trains (within the tolerance of service braking),
such that no train shall come to stand less than a trains distance from a train or noted obstruction.

ii) The ATP critical system shall monitor train braking (service and emergency) and powering, overriding operator settings if these are insufficient to meet criteria (i).

iii) The ATP critical system shall indicate activation of criteria (ii) 'override' , in appropriate visual and auditory fashion.

iv) The ATP critical system shall include a tamper-proof logging facility, including
criteria (ii) override.

v) The ATP critical system shall include an 'All Stop!' panic facility, for activation
by appropriate authority.

vi) The ATP critical system shall include appropriate measure for the detection
indication of, and halting of wrong direction movements without authority.

vii) Should a wrong direction movement without authority be detected than the ATP critical system will apply the emergency brake.

-- 2. Critical ASR (Auto Speed Regulation) system -

i) The critical ASR system shall limit train speeds to within a maximum line speed specified for a section of line to which it applies, (subject to additional regulation by the critical ATP system).

ii) The critical ASR system shall indicate the current maximum permitted line speed to
the train operator in an appropriate and timely visual manner.

iv) Where operator action is insufficient to maintain criteria (i), the critical ASR system shall invoke automatic braking sufficient to ensure that a train is within the line speed for the line section concerned.

v) The critical ASR system shall indicate activation of criteria (iii) braking in an appropriate auditory and visual manner.

vi) The ASR critical system shall include a 'tamper-proof' logging facility, including criteria (iv) activation.


-- 3 Critical SSE (Station Stop Enforcement) system -
i) The critical SSE system shall subject to additional regulation from the critical ATP and ASR systems ensure that a station cannot be passed at speed without authority.

ii) The SSE system shall indicate a station stop to a train operator in an appropriate
and timely manner,

iii) On approach to a station, the SSE system will be activated at a distance appropriate to the line speed and braking requirements.

iv) When active the SSE system shall monitor train speed and braking, such that the
train will come to stand within the appropriate platform envelope.

v) Should operator action be insufficient to prevent an overrun,
then the SSE system shall intervene, applying a suitable braking profile for the station stop concerned.

vi) Activation of a criteria (v) override shall be indicated in an appropriate manner.

vii) Once the train is correctly berthed, the SSE system shall monitor any train motion
during station operations, applying the emergency brake should any such motion
be detected.

viii) Activation of the emergency brake in respect of criteria vii) shall be indicated in an appropriate manner.

ix) The SSE system shall be deactivated upon completion of station operations,
and departure of the train. Door closure and subsequent 'correct road' motion will be
taken as departure for these purposes. Reverse motion will result in a vii) activation
unless the SSE system is informed of the reverse direction movement in advance.

x) The critical SSE system shall incorporate a tamper-proof log , including criteria (v) and
(vii) activations.

xi) The SSE system shall include suitable arrangements for terminus platforms,
including approach control at reduced speed as required.

xii) The SSE system shall include appropriate measures for station closures,
maintaing a low speed through the closed station as opposed to an outright stop.
Deactivation of the SSE shall occur once the train has passed the closed station.


--4 Non critical SRI (Speed Recommendation Indication) system -

i) The SRI Non-critical system shall advise as to a recommended speed for a section of line to which it is applied.
ii) The SRI non-critical system shall indicate this recommended line speed to the train operator.
iii) The SRI non-critical system shall also advise of upcoming changes to the recommended line speed in an appropriate manner.
iii) The SRI non-critical system is advisory only and plays no part in train braking.