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Interesting discussion of center of mass. Cars and motions sims. Motion done right

Discussion in 'Commercial Simulators and Peripherie' started by Trigen, Aug 29, 2024.

  1. Trigen

    Trigen Active Member

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    Trigen, Aug 29, 2024
    #1
  2. cfischer

    cfischer Active Member Gold Contributor

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    I really dont like how those guys twist the physics description to their product. (and I'm a huge proponent of rotating about the center of mass of the sim/driver).
    "This is the only way cars move" "All vehicles move xyz center of mass" What a gross manipulation. He talks about objects only rotating about their center of mass. Well that is true when they fly through space. Vehicles can rotate about infinite origins (think different radius turns).

    The real issue with that sim(other than cost), is that that it's so floppy the data going to the driver is full of garbage.


    Sorry to be negative.
    If you want to read some good information about what's important in a sim, check out ansible's patents.
    https://patents.google.com/patent/US20240149177A1/en?oq=20240149177
    • Useful Useful x 1
    Last edited: Aug 30, 2024
    cfischer, Aug 30, 2024
    #2
  3. Trigen

    Trigen Active Member

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    Im more than happy to learn something new so no worries. Thanks for the link!
    Trigen, Aug 30, 2024
    #3
  4. Gadget999

    Gadget999 Well-Known Member

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    They are using double speak here to confuse

    The centre of mass in a car is not the centre of mass in you body

    By setting the sim to operate around your cente of mass the actuators do not need to work as hard - but it is still not simulating the centre of mass of a vehicle

    You will need to trim the motion profile so what you feel is like driving a car with the centre of mass in the right place and now the motors will have to work harder.

    If you drove a perfectly round car and sat in the middle, the centre of mass would be correct !
    Gadget999, Aug 31, 2024
    #4
  5. azm

    azm New Member

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    There are two "centers" so to say. In airplanes most common denotes as center of mass and center of lift (external forces of your main wings). The latter is never fixed, it changes based on flaps position etc.

    And what is important for the dynamic of the system, is not the "center of mass", but the combination of both centers, amplitudes of forces acting on them. So its not so simple at all.

    Similarly in the car, center of gravity and center of externa forces are two different things.

    Anyone telling you otherwise, is Scharlatan :D
    • Agree Agree x 1
    azm, Aug 31, 2024
    #5
  6. Stules

    Stules New Member

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    Very interesting. Great discussion points brought up as well.
    I see the aircraft/heli issue is that the pilot is nowhere near the center of mass.
    Stules, Sep 3, 2024
    #6