1M Span OctaH UAV- Poshold hover bad-Oscillations

George · December 8, 2020, 10:52am

2020-12-08 10-55-01.zip (598.0 KB)

dkemxr · December 8, 2020, 3:11pm

Perhaps the PID Rate filters are too low at 8.5Hz (I know this is the tuning guide value for 30" props). Try increasing these to 12Hz and see if there is an improvement in authority.

George · December 8, 2020, 5:12pm

OK, good idea. Tomorrow I will try it.
Thank you

George · December 9, 2020, 9:49pm

Hi, it was good idea. Now Quad is fully autotuned and flying perfectly.
Thank you

dkemxr · December 9, 2020, 10:14pm

Actually George this is good information because the Tuning Plug-In in Misison Planner isn’t well suited to large props and should be adjusted. So you just changed the rate filters from 8.5Hz to 12 Hz and then Autotuned? Can you post your Parameter file after Autotune?

xfacta · December 9, 2020, 10:33pm

Please supply another .bin log from some ALTHOLD flight after that autotune - I’d be interested to see how it all worked out.

Also in the other logs and and param files you had some settings that suit 12 cell batteries, yet voltage measurements aligned with 6cells. Current measuring wasn’t working either - that will be something very useful to fix.
There was a motor imbalance, which means CW and CCW motors are fighting each other - motor mount twist or frame twist. This will leave less headroom for valid yaw manoeuvres and even affect attitude at times.

George · December 10, 2020, 5:38am

Hi All,
I changed param to 11 Hz and than autotune. Autotune was excellent. Params are included.quad flying autotuned.param (18.3 KB)
I know that there is a problem with bigger drones. But could be solved (with good friends ). My biggest drone is on the picture. Weight 47kg, MTOW 99kg. Flight time with 15l fuel 2-3h.

dkemxr · December 10, 2020, 7:55pm

I was wondering why that Battery Voltage looked so odd.

So what we learned on your craft was the calculated ATC_ACCEL and the Rate Filter values were too low. The former is no big deal because it will just be increased with Autotune but the Rate filters being too low affected basic stability to an extent Auto Tune wouldn’t be safe to run.

George · December 17, 2020, 8:30pm

Hi, thank you for your advise. Batteries was not solved yet, but the copter is flying well and ATUN is perfectly done. Thank you

xfacta · December 18, 2020, 1:52am

You should still definitely set these:
MOT_BAT_VOLT_MAX,50.4
MOT_BAT_VOLT_MIN,39.6
Or adjust if you’re not using convention Lipo 12 cell.

George · December 18, 2020, 4:51am

OK, I will do. Tanks

Hayden_KIM_Drone_Sta · April 21, 2021, 2:20am

Hi,

I’m sorry but how can you know George’s parameter?

I’m just curious… I download bin file but I only know how to read DataFlash Logs… Would you mind let me know how to read George’s parameter by bin file.

Thank you in advance.

dkemxr · April 21, 2021, 2:28am

Extract it with Mission Planner using the “Create KML+gpx” button.

Hayden_KIM_Drone_Sta · April 21, 2021, 4:30am

Create KML + gpx button using by bin file?

Hayden_KIM_Drone_Sta · April 21, 2021, 4:38am

Can you see that parameter in Mission Planner using by the "Create KML + gpx with .bin file?

Hayden_KIM_Drone_Sta · April 21, 2021, 4:47am

Hi, I found it!

It was really 1890 value.

I tried changed file format then open the mission planner then load from file put in George’s parameter (20/12/07)
Now, I can see!

Wrong parameter. I checked it too!

I think my bin file format was wrong.

Really, Thank you for your help.