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Frame IMU unstable.. Why? [Video]
  • jphansen
  • Garug
    Is the gimbal steady during the video? is there any I2C errors? what does the real time tab show for gyro and acc? Does the gimbal work?

    If the gimbal does not work, Sounds like a broken IMU, if not I2C errors.
  • jphansen
    Yes it's hanging on the stand.. No I2C errors.. There is no matching deflection on realtime tab.. Yes it works.. But is very unstable.. When I activate follow it freaks..
  • n1000
    Do your IMUs look like that:

    https://lh3.googleusercontent.com/-u3KiwWKeCQk/VJL_l-Q7KgI/AAAAAAAAABo/wtLDZ6Xfm5w/w666-h999-no/IMG_6006.JPG
  • jphansen
    Nope.. This is the one: http://copter-rc.com/90-thickbox_default/frame-imu-for-32bit-simplebgc.jpg
  • AndrewSupport
    Hello, jphansen, please make a video about work your gimbal and place a link here.
    Did you to balance your gimbal?
  • jphansen
    Yes it's balanced and set up.. Sorry what do you mean by "work your gimbal"?
  • jphansen
  • AndrewSupport
    Hello, I need to look at working of your gimbal from the side. For example like this:
  • jphansen
  • Garug
    double post, sometimes this forum acts strange...
  • Garug
    ACC calibration doe not affect drifting, Gyro calibration does. Often gyro calibration is performed at startup (unless disabled). If the gimbal is moved during gyro calibration, it will drift. The gimbal must be absolutely stationary during the gyro calibration.

    I usually disable the gyro calibration at startup and do it using the button if needed. This makes it possible to start the gimbal at moving platform, and the startup is much faster.

    However on the video it does not look like drifting is the problem, but some kind of interconnection between axis. Is the IMU well installed. its directions need to be precisely with the gimbal axis.

    Is motor Auto performed and after that pole counts corrected manually?

    Do also follow offset AUTO.

    After these do Auto tuning one axis at the time, with good stability setting first. Hold the gimbal firmly on hand when doing the Auto PID. Keep it on position where it vibrates the most during the PID auto.
  • jphansen
    Yes both IMU's are well installed.. As you can see in the earlier post I get A LOT of interference from something.. I dont know what is it.. The interference is worst on the frame IMU.. Is it normal that the frame IMU light is on all the time?

    BTW I had it working perfectly a couple of month ago.. for a short period of time.. Dont know what went wrong..
  • Garug
    On the video, are the motors on or off?

    if on, I suppose the gimbal is badly vibrating, and needs to be tuned.

    if the motors are off, then something is seriously wrong.

    I would save the profiles and erase the EEPROM and do the basic setup again (IMU calibration, motor setup, auto tuning etc.)

    What did change from when it was operating, any HW changes? FW updated?

  • jphansen
    The motors are on.. :-) but my worry is the crazy spiking in the gyro and axis on the frame imu.. I simply can't figure out why that is?
  • Garug
    How is it if you set motors off. is there still bad noise on the IMU?
  • jphansen
    Yes :-/
  • Garug
    Did you try the erase EEPROM (will destroy all settings)

    If it still has the bad noise after that, do you have 2 IMUs? try connecting just camera IMU.

    Could be broken IMU or for some reason bad noise on the power.
  • jphansen
    I already tried that.. And the noise is minimal.. But it was minimal before that.. It's only the frame imu that has the noise.. I just don't know how to pinpoint the problem..
  • Garug
    I do not know how it could more pinpointed. If it is only frame IMU having problems, it is not the power. Most likely it is the frame IMU then, to replace it is not too expensive...
  • jphansen
    I have made several tests now.. and it seems like it the gyro in the frame IMU that is the problem.. when I turn the frame IMU off but still run the cam IMU through the frame IMU the gyro still freaks.. But when I only connect the cam IMU I have almost no noise.. Or could it be the cable?

    Where do I get my hands on a new frame IMU? my "local" dealer (http://www.viacopter.eu/") is not replying my e-mails or facebook msgs. :-/

    How could it be a power problem?
  • Garug
    Power problem should affect both IMUs. If no I2C error, not likely cable problem.
  • jphansen
    Nope no I2C errors.. Crap.. I guess I need a new frame IMU :-(
  • jphansen
  • AndrewSupport
    Hello, jphansen, please send photo of your control board mounted in your gimbal with all connected wires.
  • jphansen
  • jphansen
    Doesn't seem to work.. Try this: https://drive.google.com/file/d/0B4bjRaGseE2KQTVYWUZrRGdXSlE/view?usp=sharing
  • AndrewSupport
    Hello,
    Try use ferrite rings for all motors wires as close to board as its possible, like this:
    http://ybex.com/d/zdekax7q2oyzpz2cq0p0m32it5edc93u0qwr1fbo.html
    This wire not have ferrite ring:
    http://ybex.com/d/tf194g6kbmeuxqly26fzx5eeqpfqr4f87czhpbxo.html
    and tell us about result.
  • jphansen
    OK will try.. But I guess I would get I2C errors if it's a big problem?
    Do you know where in europe I can get them.. I have tried to get in contact with www.viacopter.eu but they never got back to me.. even though I have contacted them 3-4 times..
  • jphansen
    What size is the ferrite ring on the picture?
  • Garug
    On the video it says accelerometer not calibrated? It can show what ever if it is not calibrated.

    If no I2C errors, I do not know what ferrite rings would help.

    I would erase the EEPROM and set everything from start manually, first after Erase to ensure IMUs work as expected after calibration, if they do not, no use to continue the setup.
  • jphansen
    I already erased the EEPROM and it didn't make a difference.. I'm not able to calibrate the accelerometer on frame IMU because there is too much "noise".. it stops when reaching 50%..
  • Garug
    You need a new IMU.
  • jphansen
    I just activated the motors for the first time with both IMU's on.. and I get 1 trillion i2c errors.. Why could that be?
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