PID tuning Stable and Baro

[max]

I have a hexa with Mutiwiicopter Sirius card, Avroto 2814/11S, 30A plush ESC's and 11x4,7 APC props.

After adjusting Acro mode P to 10 it's extremely stable, also when descending rapidly. Very satisfied with how it handles. But I can't get the Stable mode to work. When in stable mode, the hexa tends to want to lean over to the left. And it seems nervous when leveling from a pitch or roll. I have calibrated ACC. Do you have any advice on Stable PID settings? Should it be close to the Acro PID settings? I raised it from 4 to 8 but it still handles weird.

I also raised the altitude/baro P to 8, but it overshoots. Do you have any advice on how to adjust this?

[max]

Tried different solutions all day. Stable/level mode is still weird. It levels ok when I release the stick, but then starts to bank more and more to the left.

[mr.rc-cam]

When in stable mode, the hexa tends to want to lean over to the left. And it seems nervous when leveling from a pitch or roll.

(1) The LEVEL's attitude bias is usually solved with the LEVEL's special trim feature. (2) The "nervous" characteristic is typically solved via the PID values. My LEVEL P is 4, but every model and pilot is different.

I also raised the altitude/baro P to 8, but it overshoots. Do you have any advice on how to adjust this?

Best Alt-Hold requires more than just ALT P. It uses the P-I from ALT and the P-D from the VEL. So you should experiment with all those settings. Also, some models will have difficulty achieving a satisfactory alt-hold so YMMV.

- Thomas

[Bledi]

Just a question what is the best order for ALT-HOLD PID tuning ? first VEL and after ALT ?

[max]

(1) The LEVEL's attitude bias is usually solved with the LEVEL's special trim feature. (2) The "nervous" characteristic is typically solved via the PID values. My LEVEL P is 4, but every model and pilot is different.

I tried to calibrate acc's in different angles without any success. But the LEVEL trim feature fixed the problem. Thank you!

Best Alt-Hold requires more than just ALT P. It uses the P-I from ALT and the P-D from the VEL. So you should experiment with all those settings. Also, some models will have difficulty achieving a satisfactory alt-hold so YMMV.

Did some tests changing VEL P-D, did not seem to make much difference. Will try more.

[ziss_dm]

Hi,

Just a question what is the best order for ALT-HOLD PID tuning ? first VEL and after ALT ?

Usually vice-versa. You need to tune inner loop (Vel) first. Same as you need to tune main PID before level.

regards,
ziss_dm

[Bledi]

of course ! I need more sleep
Thank you

[max]

Still trying to get Level mode to work. It levels fine when I let go of the sticks and stays level for some seconds. But after hovering for a while, it suddenly wants to lean to one side more and more, until I take control. Have balanced props and placed FC on different kinds of material to dampen vibrations etc. Acro mode is perfect.

Is it possible to make Level mode work perfect with Multiwii, or is it just a "works sometimes" function that should not be relied on?

[Glambert]

I have 3 multiwii : 2 quads and one Y6. I fly 2 of them only in level mode but the third one behaves like you describe. Gregory