I'm still testing/tuning my quad (680mm frame, 380Kv motors, 14.7in props) and I noticed something that is happening from time to time. It's not a voltage issue because I've got triple redundancy on the voltage supply along with the diode and capacitor on the servo rail.
What's happening is sometimes (when I'm in AltHold mode) the throttle cuts out on it's own for a split second, quad drops a foot or two, and then motor speed picks back up again. This is with a constant throttle input from me so it's not induced by me. On this last flight it did it twice - each time the thottle input from me (CTUN.ThrIn - Green line) is constant (or relatively constant) and then the throttle output (CTUN.ThrOut - Red Line) just drops out and then comes back.
I'm using copter v3.3.3, no vibration issues, fresh accel calibration, fresh compass calibration. Basically no errors or flags that I can see (with exception to a compass EKF issue but I don't think that's related). Compass/Magnetometer is mounted on a mast in the rear and motor interference is 6% or less.
Is anyone else seeing this behavior? Do you know what might be inducing this problem?
Thanks!
Replies
Fixed issue. I rolled back the firmware to AC 3.2.1 (fixed my M8N EKF issue and incessant pitiful loiter) and then changed RC_SPEED parameter to 200. Rock solid all round now.
Please see the attachment for a visual on the Throttle In vs. Throttle Out issue.