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FSX A question related to how AI is implemented

Discussion in 'AI Flight Planner' started by pcpilot2010, 27/2/11.

  1. pcpilot2010

    pcpilot2010

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    Hello All:

    This is not a question related to AIFP support per se, but more to do with a general understanding of how the AI engine works. If this has been addressed elsewhere I apologize for this post, but I will appreciate it if somebody could point me to the right resource. More specifically, I do not quite understand the reasoning for the "37 minute" problem discussed extensively in many places (for example, sections 4.4-4.6 of the AIFP users' manual).

    First let me summarize what I know/believe on the inner workings of the AI engine. The surface of the earth is divided into about 100000 sectors (section 4.4). So, a collection of compiled traffic bgl files essentially encode for each of these sectors, (a) a set of flights that would transit the sector in question at one or more time points (with the cycle repeating weekly), and (b) for each flight in this set applicable to a sector, a list of times during the week when the aircraft would enter the sector. As I understood, this data would be STATIC, computed at the bgl compile time, based either on the speeds indicated in the aircraft files, or from the differences between the departure and arrival times in the flightplan file if the latter is indicated preceded by an @ (I am a bit hazy on this). In any case, bottom line is that the information is STATIC.

    With the above notion, when the user flies his/her aircraft, each time a sector is entered the AI engine looks up all the aircraft that would enter that sector (and its 8 neighboring sectors) around the same time, if any, and include them in the dynamic simulation. So, if my static view is correct, then how can there be a DYNAMIC discrepancy between the "scheduled arrival of an AI flight at a sector" and "the time at which the ATC expects the flight to arrive that spot" ?!!

    Unless, perhaps, the AI engine of the FSX (a) identifies the potential flights in question from the compiled bgl's, (b) then retroactively calculates their departures from the originating airports taking the prevailing dynamic congestion and weather conditions, in determining DYNAMIC estimates of their arrival epochs at the sector, and (c) if the static arrival time shown in the bgl is behind this dynamic AI engine estimate by more than 37 minutes then things go haywire, etc. Well, if this interpretation applies then FSX is doing a hell of a lot of work dynamically, and I better wait till 10 Gbps processors are available in the market, before I upgrade my machine next :)

    Thanks.

    Ravi
  2. gadgets

    gadgets Resource contributor

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    Ravi, there is no single document that will answer all your questions.

    The Ttools reference manual has a good overview of AI operation. Also, the TTools source code is available. While you may not be a programmer, it is extensively commented. As well, there are numerous discussions in this forum and others about the internal workings of the AI engine. You'll have to work your way through a lot of "chaff", but there's liitle about AI that hasn't been discussed at one time or another.

    Don
  3. pcpilot2010

    pcpilot2010

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    Thanks !

    Don:

    Thank you for the suggestions, and I will be pursuing them. Thank you also for a great product !!

    Ravi
  4. jvile

    jvile

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    Ravi

    One of the resources Don used during the early developement of his AIFP came from Reggie (Rfields) and myself (jvile). I explain the 37 minute rule in this single post here at FSdeveloper

    http://www.fsdeveloper.com/forum/showthread.php?t=9588

    We also spent time explaining the TNG flag for both FS9 and FSX with a little info from FS2002 at this post here at FSdeveloper.

    http://www.fsdeveloper.com/forum/showthread.php?t=9733

    If you want to read most of the beta test results and history that help develope AIFP it is at this post

    http://www.fsdeveloper.com/forum/showthread.php?t=8952

    FSdeveloper has a forum for Living World and AI at the following

    http://www.fsdeveloper.com/forum/forumdisplay.php?f=109

    hope this is helpful
    Last edited: 1/3/11
  5. pcpilot2010

    pcpilot2010

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    Thank you

    Thanks Jim for all the references. Let me try to absorb the material slowly, and will reply after that...

    Ravi
  6. Geoff_D

    Geoff_D

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    By TTools, so you mean the FSX Traffic Tools. ??

    If so, where is the Traffic Tools Source available ??
  7. gadgets

    gadgets Resource contributor

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    No! I mean TTools 2, which should still be available from Avsim/Flightsim,etc.

    Avsim/Flightsim.

    Don

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