1. Do not share user accounts! Any account that is shared by another person will be blocked and closed. This means: we will close not only the account that is shared, but also the main account of the user who uses another person's account. We have the ability to detect account sharing, so please do not try to cheat the system. This action will take place on 04/18/2023. Read all forum rules.
    Dismiss Notice
  2. For downloading SimTools plugins you need a Download Package. Get it with virtual coins that you receive for forum activity or Buy Download Package - We have a zero Spam tolerance so read our forum rules first.

    Buy Now a Download Plan!
  3. Do not try to cheat our system and do not post an unnecessary amount of useless posts only to earn credits here. We have a zero spam tolerance policy and this will cause a ban of your user account. Otherwise we wish you a pleasant stay here! Read the forum rules
  4. We have a few rules which you need to read and accept before posting anything here! Following these rules will keep the forum clean and your stay pleasant. Do not follow these rules can lead to permanent exclusion from this website: Read the forum rules.
    Are you a company? Read our company rules

Flypt Filter Research (or why doesnt my rig move right?)

Discussion in 'FlyPt Mover' started by Historiker, Feb 13, 2020.

  1. zhai1987

    zhai1987 Member

    Joined:
    Sep 7, 2021
    Messages:
    93
    Balance:
    306Coins
    Ratings:
    +11 / 0 / -0
    My Motion Simulator:
    2DOF, 3DOF, AC motor
    Flypt Filter Research
    91517 91518

  2. zhai1987

    zhai1987 Member

    Joined:
    Sep 7, 2021
    Messages:
    93
    Balance:
    306Coins
    Ratings:
    +11 / 0 / -0
    My Motion Simulator:
    2DOF, 3DOF, AC motor
    Sir, can you tell me how to set it up? Flypt Filter Research
  3. Dirty

    Dirty Well-Known Member Gold Contributor

    Joined:
    Oct 15, 2017
    Messages:
    736
    Occupation:
    All the way up front.
    Location:
    Germany
    Balance:
    7,826Coins
    Ratings:
    +859 / 2 / -0
    Hmmm,... not really. I have no experience with these racing rigs. I only use 6DOF Stewart platforms. What I would recommend is to experiment and play around. Initially, use only a single DOF (like 'pitch' for example) and apply a EMALP(EMAHP(VALUE)). 'Value' in this case should be 'Acceleration Longitudinal with Gravity', but play around and find what you like best.

    I know, this is not a satisfying answer, but think of it like this:
    It's like asking "I want to motivate people. What should I say?" The only real answer would be "Depends on what you want to motivate them for." So, the question to ask is not: "What should I say?" but rather "How do I become a compelling speaker?".

    And in the context of motion sims that question would be: "How do I understand filters?" to which I would recommend: Build them yourself in Excel and look at the curves. Get a feeling for what those curves mean.

    Sorry, for not being of much help here :-/
    • Like Like x 1
    Last edited: Jun 21, 2022
  4. Dirty

    Dirty Well-Known Member Gold Contributor

    Joined:
    Oct 15, 2017
    Messages:
    736
    Occupation:
    All the way up front.
    Location:
    Germany
    Balance:
    7,826Coins
    Ratings:
    +859 / 2 / -0
    Maybe there are others who use such a rig who can share their profile. That would give you a good starting point.
  5. Dirty

    Dirty Well-Known Member Gold Contributor

    Joined:
    Oct 15, 2017
    Messages:
    736
    Occupation:
    All the way up front.
    Location:
    Germany
    Balance:
    7,826Coins
    Ratings:
    +859 / 2 / -0
    Finally made a few more :-D This time in full-on 4K :-D

    Here's the first one:
    • Informative Informative x 2
    • Like Like x 1
    • Winner Winner x 1
  6. Rolo F

    Rolo F New Member

    Joined:
    Oct 28, 2020
    Messages:
    26
    Balance:
    221Coins
    Ratings:
    +7 / 0 / -0
    My Motion Simulator:
    Arduino
    Hello!

    Does someone know where I could find all these filters for excel?

    What do I want to do /why do I want them?

    I want to record the telemetry of a few laps, then export it to excel (there is where I need the filters formula) and then I should have the output...

    As I'm using multiple direct modules, I want to see "live" how changing the parameters of the filters affect the graph of the motion (that I'm going to make with excel)

    Is true, we have a graph viewer, but I can't analyze it and see the real change, I cant pause it and compare one graph to another...

    Just need the formulas in excel and import the data...

    BTW... another question...
    The Multiple Direct, to calculate the output, just "adds" all the outputs of each parameter/variable? Regular addition of each value?


    These are the values that I want to "play" with:

    [​IMG]

    So... moving each parameter I want to understand how the "total" curve moves, and by looking at them (a static graph on time) I can make tune it to the way it should be...

    Thanks!!!!
  7. Dirty

    Dirty Well-Known Member Gold Contributor

    Joined:
    Oct 15, 2017
    Messages:
    736
    Occupation:
    All the way up front.
    Location:
    Germany
    Balance:
    7,826Coins
    Ratings:
    +859 / 2 / -0
    I think that's a cool idea!

    Essentially all you have to do is extract the data, write it into an Excel spreadsheet, then model the filters you want to use (one collumn each) and you can plot the output graph that shows you which values your DOF would've had if you had used those filters. And then you can play around with the filters and see the result directly.

    That would actually be a cool software on its own already. Even better if you integrated it into a motion cueing software.

    Cheers,...
    Last edited: Jun 22, 2022
  8. Dirty

    Dirty Well-Known Member Gold Contributor

    Joined:
    Oct 15, 2017
    Messages:
    736
    Occupation:
    All the way up front.
    Location:
    Germany
    Balance:
    7,826Coins
    Ratings:
    +859 / 2 / -0
    One more :) This time about high pass filters:
    • Winner Winner x 2
  9. hexpod

    hexpod http://heXpod.xyz

    Joined:
    Apr 18, 2016
    Messages:
    1,093
    Location:
    berlin
    Balance:
    7,091Coins
    Ratings:
    +336 / 5 / -0
    My Motion Simulator:
    DC motor, 6DOF
    Maybe you could record and export the telemetry with different filters, than view the end result in excel.
    Not better ?
  10. Dirty

    Dirty Well-Known Member Gold Contributor

    Joined:
    Oct 15, 2017
    Messages:
    736
    Occupation:
    All the way up front.
    Location:
    Germany
    Balance:
    7,826Coins
    Ratings:
    +859 / 2 / -0
    If I understoood correctly, I think the idea was to export the inputs to the filter in order to be able to then go and try out different filter settings and observe in an instant how the output would've changed.

    Instead of having to actually drive/fly the sim, you could try out different setting and you would see the effect directly. By "seeing" I mean in the graphs.

    Cheers
    • Like Like x 1
  11. Rolo F

    Rolo F New Member

    Joined:
    Oct 28, 2020
    Messages:
    26
    Balance:
    221Coins
    Ratings:
    +7 / 0 / -0
    My Motion Simulator:
    Arduino

    Dirty, if you feel this is off-topic, please let me know to erase it...

    What happened? I have an active harness (sim racing). A few months ago, I pick up a friend's track car, install a device that captures the tension of the belt, shoulders, and waist, and drive some laps. After that, for making it simple I pick up a big turn, a big breaking point and with those values, I did a ratio (for example 7:4.. this is the shoulders receive 3/4 more strength than the waist). So I build a harness that keeps that ratio when it pulls the harness (is not that specific one.. I don't remember right now).

    I have some idea of the forces that are involved in the tension of the harness, longitudinal accel, lateral accel, and vertical accel (when you brake, turn, and go through a bump for example...); and of course when you have it tight, some vibrations of the car you can also feel them...

    So an exclusive Mega board for the belt, a servo motor, FlyPt and... A multiple direct where I pick up all those values and apply some filters and violà...

    The result is "mmmmmm"... I know what I should feel in some scenarios, I know how much force or strength I should feel and how should I feel it.... If I make a graph strength/time in a known curve, for example, I have some idea of how that graph should be..

    Now, the real thing is that I really don't know how will affect changing a parameter, the graph function of Flypt does not let me for example analyze what happens to the movement of the actuator if I change a parameter because when you hit pause, all goes to 0.

    So... here comes my idea...

    If on one hand, I have all the formulas of the filters in excel, if I know the way multiple variables (long accel, vert accel, lat accel for example) are "joint" together to have the output of the actuator and, by the other hand I have the way to get all the telemetry (raw data of long accel, vert accel, lat accel), I could load those values to the excel sheet, apply the formulas with the parameters that I have and I would have the output to the actuator (it should be same as the actuator behaves because it is "calculated" the same way. That way I will have the behavior of the actuator in the period of time that the values of the telemetry have (I know that each value is calculated every 2ms).

    Now.. that's my baseline. Then I copy/paste those same values and start changing the parameters of the filters and I could compare how the actuator would behave under the same situation. As I know how it should feel (or the actuator does under that circumstance) I could twitch the parameters of the filter or change the filter to get the behavior that I'm looking for under that scenario.... Once I'm ok with the result, apply it and for sure I will have the feedback I'm looking for.

    I can apply ceteris paribus, one input at a time, for example under breaking...with abs active is different than without the abs acting and the ideal max braking force is the top of the strength I should feel, then down...

    Then I can go to a turn, and then to Eau Rouge and pick up the telemetry... and at the end... I pick up a curve and break in the middle...and so on.. that way I could find a nice setup for, in this case, my belt... but this could be applied to ANYTHING...

    So what do I need:
    -The math of each filter, is ideal if there is a complement for excel (faster)
    -how to export telemetry (recording) to excel, I have tried but it's alien to me

    This is my dream, but if I don't know the math of the Flypt filters...all that we could take from the excel would be nothing because the parameters in excel would not make the same in Flypt (output)

    I think is a good idea and it will help me a lot... what do you think... maybe it's a very stupid idea...or maybe impossible... but the creator of Flypt is in this forum also.. he could give us the info...

    If someone gets here reading, MASSIVE THANKS for your time... please leave your opinion... and sorry for my English, not my mother language, hope I manage to explain myself in the correct way

    Have a great week!!

    [​IMG]
  12. Rolo F

    Rolo F New Member

    Joined:
    Oct 28, 2020
    Messages:
    26
    Balance:
    221Coins
    Ratings:
    +7 / 0 / -0
    My Motion Simulator:
    Arduino
    All the book I wrote before...
    Here you can read it in one paragraph...:grin:grin:grin
    • Funny Funny x 1
  13. Dirty

    Dirty Well-Known Member Gold Contributor

    Joined:
    Oct 15, 2017
    Messages:
    736
    Occupation:
    All the way up front.
    Location:
    Germany
    Balance:
    7,826Coins
    Ratings:
    +859 / 2 / -0
    Here's an introduction to the idea of convolution:


    Essentially all it says is:
    1. Any descrete-time signal can be considered as a series of impulses. The response of the filter to the signal is then just going to be the sum of the impulse responses to each individual impulse.
    2. Similarly, any descrete-time signal can be considered as a series of steps. The response of the filter to the signal is then just going to be the sum of the step responses to each individual step.
    I will stick to using the step response as an example, because I find it easier to imagine a situation in motion cueing where the signal makes a step, rather than imagining a series of impulses.

    The video is more of the nice-to-know than the need-to-know sort :)
    • Like Like x 3
    Last edited: May 1, 2023
  14. Dirty

    Dirty Well-Known Member Gold Contributor

    Joined:
    Oct 15, 2017
    Messages:
    736
    Occupation:
    All the way up front.
    Location:
    Germany
    Balance:
    7,826Coins
    Ratings:
    +859 / 2 / -0
    ...and trying to put everthing into context. Here's the" bigger picture" of what motion cueing is and what the filters' job is.
    • Like Like x 2
  15. Dirty

    Dirty Well-Known Member Gold Contributor

    Joined:
    Oct 15, 2017
    Messages:
    736
    Occupation:
    All the way up front.
    Location:
    Germany
    Balance:
    7,826Coins
    Ratings:
    +859 / 2 / -0
    Finally done with conversion training on the A340, so I had a few hours to spare. There's a lot in this video, so it might be a bit convoluted. I described how the "classical" filter based algorithm turns acceleration signals into translation commands. I used longitudinal acceleration --> surge in this example, but it is just as valid for lateral and vertical acceleration signals. Enjoy :)

    • Like Like x 3
    • Winner Winner x 1
  16. Klaus Schmidinger

    Klaus Schmidinger Member

    Joined:
    Oct 3, 2022
    Messages:
    32
    Balance:
    246Coins
    Ratings:
    +9 / 0 / -0
    My Motion Simulator:
    AC motor, Motion platform, 6DOF
    I am using FlyPt Mover and trying to achieve the behavior as shown in the red curve (screenshot taken from the video in the above posting):
    upload_2022-12-20_15-58-37.png
    However, the best I can get is something like this:
    upload_2022-12-20_15-53-10.png
    This is more like the yellow curve than the red one.
    Here's a screenshot of my FlyPt Mover setup:
    upload_2022-12-20_15-56-26.png
    The filter in use is DEMALP(EMAHP(VALUE;100.000);5000.000).
    Am I doing something totally wrong here?
  17. hexpod

    hexpod http://heXpod.xyz

    Joined:
    Apr 18, 2016
    Messages:
    1,093
    Location:
    berlin
    Balance:
    7,091Coins
    Ratings:
    +336 / 5 / -0
    My Motion Simulator:
    DC motor, 6DOF
    Yes, you have to use “filter ordering”. Just put a two or 3 EMALP in cascade to eradicate the entry corner
    • Informative Informative x 1
  18. Hugh Jengine

    Hugh Jengine New Member

    Joined:
    Mar 27, 2020
    Messages:
    3
    Balance:
    2Coins
    Ratings:
    +0 / 0 / -0
    Hello. Thanks for all the great information. I was wondering if someone could help me. I built a 6DOF platform. Then I broke it due to huge shock loading after hitting the wall exiting Radillon. True story. So now I’ve rebuilt it replacing 3D printed CF nylon parts with billet machined parts. But I still have a problem with crashes sending huge shocks and tripping Odrives with over current. My dilemma is if I make the system pass high frequency so it replicates texture like kerbs and grass, how do I filter spikes from when I hit the wall? Any help would be appreciated. Thank you.
  19. Hugh Jengine

    Hugh Jengine New Member

    Joined:
    Mar 27, 2020
    Messages:
    3
    Balance:
    2Coins
    Ratings:
    +0 / 0 / -0
    So I think I found it. Do I need to use
    SPIKE, EDYNLP and LDYNLP?
  20. Klaus Schmidinger

    Klaus Schmidinger Member

    Joined:
    Oct 3, 2022
    Messages:
    32
    Balance:
    246Coins
    Ratings:
    +9 / 0 / -0
    My Motion Simulator:
    AC motor, Motion platform, 6DOF
    With EMALP(EMALP(EMAHP(VALUE;80.000);1000.000);1000.000) I get this:
    upload_2022-12-20_22-10-28.png
    There is still a sharp corner at the beginning.