Hi,
I've a feeling I'm going to have to send in the drone for repair, but I figured I'd ask about the issue first.

I won't go into too much detail, but essentially the drone fell about 200ft into relatively soft earth hitting a few brances on the way down. It is still able to fly however I can't clear an IMU Calibration error on it. And after trying, I see that the Accelerometer ACCO is showing a Data Error. I did ensure the smart controller's firmware was current before calibrating.


Anyone have any suggestions of something else I could try, or should I just send it in. If I have to send it in, any idea as to the turn around time?

Thanks!

Hi there. Thank you for reaching out and we're sorry to know about the incident that happened to your unit. You may perform the IMU calibration to see if the issue persists. However, if it still does the same issue, I'm afraid that you may consider sending the unit in for a proper diagnosis. You can contact our support team to start up a ticket at https://www.dji.com/support. Thank you for your understanding and support!

IMU "Inertial measurement unit" .

As far as I see it, IMU calibration on a level surface updates a table of values the flight controller software uses as a reference for a level stationary hover. From there the craft responds predictably to flight commands.  It also likely measures any sensor noise and thermal drift so that these technical imperfections are accounted for when using IMU sensor data in flight. - this is likely why there must be no vibrations during the calibration process.


Bad IMU calibration could cause drift and attitude issues as the flight controller fights to hold the craft in what it thinks is the correct attitude as opposed to the correct physical attitude.


The IMU usually has 2 types of sensors – angle and acceleration and in turn 3 sensors of each type measuring in the X,Y and Z axis. These sensors can, through vibration, aging, impact etc, drift in their response over time and thus an IMU calibration will establish a new reference for the IMU’s level/stationary state that the flight controller can work with to restore stable flight.


Think of calibration as the bringing back into line the measured craft attitude with the true physical craft attitude.


As to how often an IMU calibration is needed, Refer to your manual ; certainly after any impact or if there are suspicions the craft can’t hover in a level attitude in a windless environment. Also after a firmware update is a good opportunity just in case the stored values get corrupted or are incompatible with the later firmware.
I did put this piece together because at least 1 person seemed to have a problem, I think Bad IMU.