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FOC and RC Helicopter (25KG)

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Tue, 2022-03-15 23:30
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Flyingtux
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FOC and RC Helicopter (25KG)

Hi,

I'm trying to migrate from castle creation BLDC to vedder Maytech 75_300 FOC but not without any problems. I'm using 2x 12S8P li-ion batteries in // and a hacker Q80 28 motor (kv180, 5500W in burst).

Without blades, it seems working to run to the consign (speed pid without reverse, or current, foc or bldc). But with small air drag test blades an oscillation arrives during the increase and vesc stop abort increase. I need to increase to 105000ERPM. I set the frequency to 50KHz.

 

here a snapshot of the oscillation : Screenshot from 2022-03-15 19-33-13.png

Thanks for help ;-)

Regards,

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Fri, 2022-03-25 18:59
skyline1970
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VESC Free
Joined: 2017-09-07 22:28
Posts: 232

Reducing frequency?

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Tue, 2022-03-29 17:12
Flyingtux
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Joined: 2021-08-23 17:00
Posts: 16

Hi,

Thanks for advise

I found a workaround by increasing frequency to 60kHz and avoiding to use the internal speed pid.

The speed estimate is noisy around 60000erpm and above. Increasing to 60KHz reduces this speed state noise but not enough to regulate with the internal speed pid.

It could be good to have a state filter inside the speed pid to avoid that.

I noticed too that the "speed pid no reverse"  brakes my rotor despite that brake is disable in the conf. Do you confirms that ?

 

 

 

 

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