ABS/tire lock telemetry

Discussion in 'General Discussion' started by GTClub_wajdi, May 10, 2022.

  1. GTClub_wajdi

    GTClub_wajdi Registered

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    Hi
    rfactor2 is the best sim out there but it’s incredible that rfactor2 doesn’t send any telemetry for ABS and tires lock. I have motion system and Sim3D rumble kit for my pedals and sadly ABS and tires lock isn’t supported because there are no telemetry produced from rfactor2. all the other sims like iRacing, ACC, AC, even old sims like GTR2 have them all. Please Studio397 can you resolve this issue? I bought Sim3D and they are useless with rfactor2 . Thanks
     
  2. Lazza

    Lazza Registered

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    The sim provides wheel rotation speeds and patch velocities, what will ABS and tire lock channels provide that they don't? That's actually an honest question. (well, it's a poorly worded one mind you - what I mean is, how much can't you work out with those that an ABS or tire lock channel will provide? To be fair I haven't done much driving with ABS, but I imagine Filtered Brake will show something you could probably use...)
     
    Last edited: May 10, 2022
  3. GTClub_wajdi

    GTClub_wajdi Registered

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    I contacted SRS team Engineer ( Sim Racing Studio) which support Sim3D rumble kit and my motion system and he provided me this

    We need to know with EXACTITUDE when the wheels spin under acceleration, lock under breaks and when abs activates.

    Other variables that allow to compute approx those cause fake positives and are not usable.
    False positive

    The key is EXACT indicators”

    Can you please put me in contact with Studio397 engineer so SRS can contact them ?
    I’m doing this not only for me but for all rfactor2 users who can’t benefit from these features.
     
  4. Lazza

    Lazza Registered

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    I'm just a user like you.

    ABS might be tricky, but I'd imagine a game-provided channel for wheelspin or brake locking will use the same telemetry data to detect it and provide that channel. I mean, how would you do it with a real car? Surely the same way?
     
  5. GTClub_wajdi

    GTClub_wajdi Registered

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    Firstly thank for your rapid answer.
    I’m really not into these things ,,however they told me they will contact Studio397.
    I’m contacting SimHub team as well.
     
    Last edited: May 10, 2022
  6. ThomasJohansen

    ThomasJohansen Registered

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    how does simhub, figure this out, because, wheel spin and brake lockup are available for pedal rumble, and for me it feels correct.
    Though I dont think I can feel ABS, but not sure, since I have it toned down to only give me feedback for wheel lock.
     
  7. Lazza

    Lazza Registered

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    @GTClub_wajdi I had a quick go in the Bentley and unfortunately it looks like ABS isn't shown in the Filtered Brake position channel. Makes me wonder if that and the normal brake pos channel will ever NOT match, but anyway - that takes away a potential easy detection. (whether that has something to do with 4-wheel ABS I don't know, but if it's not there on some cars it's a fairly useless tool anyway)
     
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  8. Kevin van Dooren

    Kevin van Dooren Registered

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    You can already determine when ABS kicks in.
    When the difference between brake pos [%] and total brake pressure [%] is nonzero, ABS is kicking in.
    If the max brake pedal force in the car setup is not on 100%, you'll have to apply a scaling factor to the total brake pressure such that it reaches 100% instead of the max pedal force %.
    This can be done automatically by determining the channel max value of the total brake pressure output.

    Wheel locking/spinning is evident by the difference in wheel speed of left and right, and combining it with either brake or throttle input.
     
  9. Lazza

    Lazza Registered

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    In addition to what Kevin says, you can also access the UserData\player\tempGarage.svm file and pull the brake pressure % out of there. That's where my plugin gets all the car setup values from.
     
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  10. GTClub_wajdi

    GTClub_wajdi Registered

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    Hi bro
    SimHub responded to my email
    This is the response from Nicolas
    Unfortunately rfactor2 does not expose that specific data, so simhub is facing the same restriction.
    Can you please put me in contact with Studio397?
    It seems that rfactor2 put a lot of telemetry data restrictions and this sucks because tires lock and ABS is very important for users who have motion and bass shakers…… so even Sim Hub doesn’t support these features.

    Best regards,
    Nicolas
     
  11. GTClub_wajdi

    GTClub_wajdi Registered

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    SimHub doesn’t support these features In rfactor2.. at least Nicolas says this
     
  12. ThomasJohansen

    ThomasJohansen Registered

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    @GTClub_wajdi would all these missing info's in the shared api, qualify for a bug report? Now that @Coutie are looking into bugs?

    Not to hihack the thread, but if doing a bugreport, I also miss:
    onboard TC level
    onboard ABS level
    Temps from GTE
    Bottoming
     
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  13. Lazza

    Lazza Registered

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    Can I pull you on up on that for a second? No, it's not a bug report, because 'ABS activated' etc isn't provided data. So it's a missing feature, or data (as is the current TC and ABS level, absolutely), but it's not a bug. Coutie is marking threads more these days and occasionally says it's being looked into, but said himself that him marking threads as 'WIP' etc doesn't necessarily mean they're being actively looked into.

    Can we focus a bit more on what data is missing? Not just "the data isn't exposed".

    Kevin outlined above what indicates ABS kicking in, and brake pressure can be factored in via the setup value which is also accessible after jumping into a car. So while there isn't a "ABS active" channel directly provided, you can work it out yourself via the provided information.

    Wheel lockups, again I'd ask how the real-life lockup indicators work, because surely they work it out from onboard telemetry. Just because the game doesn't provide a "Lock up" channel doesn't mean you can't work it out.

    With all 'sensors' disabled I can still see wheel rotation speeds and ground/patch velocities. As a wheel locks up its longitudinal patch velocity (relative to the ground) approaches the longitudinal ground velocity (how fast the ground is going past that wheel). You could ignore those values below x speed, check for brake application before checking the values at all, and work out a fraction you decide is a brake lockup.


    So: what's wrong with the provided data? Why can't that be used?
     
  14. Seven Smiles

    Seven Smiles Registered

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  15. GTClub_wajdi

    GTClub_wajdi Registered

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    Well, if 2 big sim racing softwares like SRS and SimHub both say that sometimes is missing to implement these features then something is lacking I guess . Some one told me rfactor2 doesn’t provide these data so people can’t cheat but why all other sims even “ sim arcade” provide these data but rfactor2 the most perfect sim in the market doesn’t?!
    I hope we can have some answers from Studio397 engineers.
     
  16. Lazza

    Lazza Registered

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    Maybe you can point Nicolas to this thread, or even have him contribute to this discussion? Plugin developers are telling you that this should be able to be calculated. That's what plugins do. We seem to be stuck on what the game explicitly provides, when that doesn't seem necessary.
     
  17. William Levra-Juillet

    William Levra-Juillet Registered

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    Hello everyone,
    I'm new to RF2 plugin development and I need to detect when ABS kicks in.
    I tried to monitor filtered and unfiltered brake values but they seem to be always the same

    Thank you @Kevin, that sounds interesting!!! Unfortunately I'm a bit lost regarding what you mean by brake pos and total brake pressure. Is it per wheel?
    Also not sure how to retrieve the channel Max value?
    Could you point me in the right direction?
    Thanks a mil
     
  18. GTClub_wajdi

    GTClub_wajdi Registered

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    I believe in the last build we have some progress in the telemetry output? Now I think rfactor2 output the telemarketing of ABS and tire slip? can somebody correct me?!
     
  19. Lazza

    Lazza Registered

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    What?
     
  20. Lazza

    Lazza Registered

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    As @Kevin I think is approaching this from the telemetry point of view, I don't think he'll mind me chiming in here as a plugin developer.

    The plugin inputs you'll need, via the plugin interface:
    Brake pedal position (%) (probably best to use filtered, in case it deviates from unfiltered, but might need to test which is correct in that scenario)
    Rear brake bias (%)
    Brake pressure (%) FL, FR, RL, RR

    From a quick 2 min test, I think that's it. The game appears to automatically scale the setup brake pressure. (I thought brake pressure would scale with setup max brake percentage - but I just tested with 80% in the setup and it seems not. That makes it even easier!)

    At 100% brake position, the brake pressures will match the brake bias. So if your rear brake bias is 54% (46:54), your brake pressures will read 0.46, 0.46, 0.54, 0.54. As your brake position lowers from 100%, the 'full' pressure for each wheel will scale down accordingly. So what you want to detect is when the pressure is lower than that max figure - that means ABS is kicking in. Here's a graph to illustrate:

    upload_2022-10-8_7-45-8.png

    You can see the brake pressure at various wheels is lowering from their 'full' position, scaled to the brake pedal position. Just detect that, possibly with a little 'deadzone' to avoid any rounding getting picked up, and you should be good. Up to you how you handle individual wheels vs both front or both rear (some cars won't do individual wheel ABS, though I guess most will).
     

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