Ai Generated Timetables

Discussion in 'Train Sim World Discussion' started by Tank621, Apr 4, 2022.

  1. Tank621

    Tank621 Well-Known Member

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    So as I understand it some of the timetables in the game are created through AI generation through which an AI starts at a set time time and the subsequent timings for stops along the route are created based on the AI's run of the route.

    The alternative to AI generation is I assume manual timing entry, based on real life timetables which I assume to be a much lengthier process.

    Now, assuming my understanding is correct there are a few issues with AI generation but I am going to focus on one for now as something of a thought experiment.

    Now as timetable mode is one of the core advances made by TSW over TS this is a much greater issue for TSW over TS and has wide reaching consequences.

    For example, the use of AI timetables inhibits the ability to make alterations to the physics of the trains. If the acceleration or braking of a train is inaccurate then correcting it renders the AI generated timetable redundant as the timings can become an impossibility. It would seem that improving the accuracy of just one train with timetables on multiple routes potentially being affected.

    The consequences of this go further too, surely it is harder to notice when a loco's performance is not quite right if it is running a timetable set by the performance of itself rather than a real timetable. Similarly if correcting the physics of a locomotive can effectively break the timetable(s) then the timetables would have to be remade to fit the new physics of the locomotive then the workload becomes massively increased and potentially unviable. The result is that the physics of the train may not be able to be altered to better relfect the real train.

    With a simulator people desire the closest reflection of reality possible and we are certainly all aware of just how passionate people are in achieving that. It seems to me, that AI generated timetables not only often fail to match reality but can result in being stuck with a train with physics that aren't up to scratch, the consequences of which can impact other aspects such as sound.

    In all, my understanding may not be entirely correct and I am almost certainly thinking of the worst case scenario in terms of the consequences of this, though in my mind 'prepare for the worst, hope for the best' is usually the best course of action.

    From this I would like to ask a few questions:

    First, is my understanding of how AI generated timetables are created correct and if not, how it does?

    Secondly I would like to know which routes rely on AI generation to create the bulk of its timetable, mostly out of curiosity.

    Also, I would like to know if this process is still being used.

    Finally, I would like to understand the benefits and limitations of AI generation in order to further my understanding and open a discussion into the attitudes of timetable development in TSW as a whole.
     
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  2. Trenomarcus

    Trenomarcus Well-Known Member

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    From my understanding of the timetable thing, DTG used the "manually" entered timetable for a long time, in most if not all content (likely it is not really a full-manual process, but still). Nowadays, to be quick but dirty, started to use "AI-generated" timetable more often, which means basically given the start time of the services, let the system simulate a full day run and then use the passing times to stations, etc, as the timetable. A "performance" parameter compensates for the difference between a real train and a simulated one, basically meaning for example that the simulated performance will be "XX%" less than the real counterpart.
     
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  3. Tank621

    Tank621 Well-Known Member

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    I can understand why the AI generation is appealing, after all, game development is always a compromise of time, money and vision.

    It just feels like they'd be backing themselves into a corner when it comes to future changes to the locomotives especially.

    In my mind it makes sense to run the trains to the timetable, rather than the timetable to the trains which is the case with AI generation.
     
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  4. Suomen surkein junakuski

    Suomen surkein junakuski Well-Known Member

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    0dc7d16f-018b-4f97-80af-af1e84e94ed9 (1).jpeg
    One question what comes into my mind about the AI-timetables, is that why they always have to be so spesific. Like in this case the arrival time is 16:48:03. Why can't it just be 16:48? Can't the programme just round it up or something? This is probably the most annoying thing about the new routes, and now it is introduced to older one's as well.
     
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  5. Matto140

    Matto140 Well-Known Member

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    They set and need seconds for proper timetable simulation and function of signaling(virtual dispatcher).
    It is about system setup and precision of train positions after game world loads.
    AI Trains loads in static position and then accelerate so every moving train in loading moment is then late (few seconds), if precision is lower that it can cause more probems (especially on bussy route hubs).
    Maybe they could hide seconds for player interface and provide player time format option (24hours/12hours - HH:MM:SS/HH:MM)
     
    Last edited: Apr 5, 2022
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  6. Trenomarcus

    Trenomarcus Well-Known Member

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    Internally in the timetables there are 2 values, one is the "simulated time", and one is the "expected time". If the expected time is empty, the simulated time is used (just a simplification for the sake of argument). In the newest timetables, the latter is often the case. I agree, I'm not sure why they do not just run a simulation, round it up, then use the values as a baseline for the expected times. Then fix collisions, etc., and make the final timetable. Using the simulated timetable is just poor and leads to dirty results.
     
  7. ARuscoe

    ARuscoe Well-Known Member

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    Really that should be rounded up to 16:49:00 to allow some slack in the timetable

    This would be my expectation. Use the automated times (rounded up to a full minute) then run it again to check for collisions, make changes, check until resolved
     
  8. Inkar

    Inkar Well-Known Member

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    They have different ways of creating the services in the timetable. Sometimes they just added the start time and let the AI figure out the rest. Sometimes they used the real timetable times. Sometimes they used a mix of the previous two methods. I think they have a new method now that uses the start time and a displacement in minutes for each of the stations. That way they can make 1 service using the real timetable as a base and then copy it to make more just changing the start time.

    I don't think there is a list, but keep in mind that the start time + minute displacement for each station method is quite new. I think it probably came with RH. So older routes will not have it.

    I guess they try to use the most appropriate method for each situation. You can tell that the timetables in new routes are quite better than they are in the older ones.

    You might want to watch this video where DTG explains how they make the timetables. Keep in mind that it is a few months old, so the newest method (start time + displacement in minutes) is not explained there.

     
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