Hi guys, I have not followed the last release, so I got very upset when I updated my old, steady 3.2.1 Octa-Quad multirotor with the new 3.3.2. Of course I do realize that my system is kind of a mess, because I am using that multirotor for research and testing, so I know there are some vibrations and even some magnetic disturbances. Besides, the 3.2.1 had been flowing just fine. 

I installed the firmware, did all the calibrations (accelerometers, magnetometers, motors, esc..) and went flying. 


I attached the telemetry, but here there are some figures:

Throttle Out:



Accelerometer Bias

Here is the only bad result from an autotest:

Test: IMU Mismatch = FAIL - Check vibration or accelerometer calibration. (Mismatch: 2.61, WARN: 0.75, FAIL: 1.50)

I tried to play a little bit with the EKF parameters, but got worst, so I would like to share my experience for you guys can help me to find the best direction to move on and get rid of this (only) issue.


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Mr. paul riseborough adviced to switch off the IMU1 in 3.3. The software in 3.2 use only IMU2,  this way the set will be same like APM 3.2.

Yes, I did a new complete calibrations of acc, magneto and motors. The Buzzer you hear in the video is because my batteries were low. I had to connect a separate buzzer because the power module I have is measuring 1volt less when is under load. I have completely removed the buzzer, too annoying.....

I get there is a vibration issue and I am going to work on it and keep the post updated. What I do not understand is why the very same vibrations do not affect the estimations and control in the old release

You fly in windy conditions the other vers?

Old release use IMU2 (second accelerometer) only, that is different, not so critical to vibrations.

Yes, very windy but still stable. That is what I am going to do guys: I will try to reduce the vibes to the minimum (no promises) and I will fly both the release next week and post video and telemetry

Ok, here I am. Unfortunately the weather is not good to let us fly outdoor, but I did calibrate the propellers and used mounted the autopilot on the damping bed I've been suggested. The props where balanced horizontally, but not vertically (that was enough before). I also used the VIBE tool to dynamically adjust the propeller angular setup (and it really helped, as one motor was slightly vibrating).

Here is the screenshot of the Vibration graph in an indoor test. As soon as I can I will test the althold. Stay tuned!


... I just realized the typos in my post.... hate automatic correction

I want to share with you the Vertical speed and altitude graphs when the system is not armed end after the arming command. I am indoor, no GPS. As you can see while the vehicle is disarmed the altitude and velocity keep oscillating. The oscillations stops as soon as I ARM:

As soon as I disarm the oscillation starts again:


I did that test with Mission Planner but not noticed that.

The way the oscillations are so uniform and consistent I would think maybe that's normal? Like it's just searching for input? Just a guess. 

ahhh that must be the difference for alt hold in 3.3 then. Makes sense. 

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