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Cube Orange with strange vibe information

Hello guys,

I have tried Copter 4.1 today in my hex. This new firmware gives me a chance to look at 3 vibes data in particular IMU which I think so, because there are VIBE[0],VIBE[1] and VIBE[2] appeared in my log where just one vibe data was there in copter 4.0.7

To my understanding, the Cube Orange has 2 isolated IMUs and 1 hard-mounted IMU. Do you guys have some ideas with this graph where 1 vibe is much smaller that the others?

This is the log file for further analysing:
https://drive.google.com/file/d/1EzDJo8tDoelh0tiVSVNPejKv5YprhOp4/view?usp=sharing

Thanks,
Vu.

That is odd. Specs say IMU1 (ICM20649) is non-isolated. That IMU is identified as ACC/Gyr 3 (ID 3015690) which would seem to be the one showing the lowest vibes.

Could it be the resonance of isolating structure and my frame?

Not sure. Some will surely say you shouldn’t have an isolating structure when using a Cube Orange. That’s the “Hard Mount” cool-aid. In reality I think it’s a more complicated and nuanced problem than the Black/White Hard mount vs compliant mount. Just my opinion based on anecdotal evidence, I don’t have any Cubes.

Thanks for reminding but when I mentioned this, I meant the isolating structure inside the Cube. Will do more tests to figure out more interesting issues.

Check out this thread.

IMU Damping

BTW-It might be interesting to collect FFT reference data for all 3 IMU’s by setting INS_LOG_BAT_MASK to 7.

Hi Dave, thanks for giving me that so useful thread
“From this data, it’s plain to see that for frequencies less than 120Hz, the foam damping is amplifying the vibration that the IMUs see, thus confirming my suspicions”
I believe so!

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