Oscillation on Descent

kcukekmkc · September 10, 2021, 7:37am

I had no problem landing on my first flight today (just the bottle stuck and the drone wobbled, which was fine).
1st flight)https://drive.google.com/file/d/16lX_XKdeHatXxpgr82Vi52H6EMwwwwtO/view?usp=sharing
In the second flight, the drone started to shake while descending in loiter mode, the uavforecast application was showing the gps number 11-12, is this the problem?
2nd flight)https://drive.google.com/file/d/1OIbfrFtdZ023pM8tbDIt_ddjLFpMhjgw/view?usp=sharing

What could be the reason why it wobbled on the second flight while there was no problem landing on the first flight?

dkemxr · September 10, 2021, 12:59pm

Could just be borderline tuning. Rate PID’s are at default. Some other observations:
Maybe you fat fingered this: MOT_BAT_VOLT_MIN,178

Your vibe levels are high with a lot of clipping events (~5600) on one axis:

I would fix these things, configure the Dynamic Notch Filter (enable ESC telemetry if you have it) and get to tuning.

kcukekmkc · September 10, 2021, 2:11pm

The vibration level was less in the flights I made with the carbon propeller, I will put the carbon propeller back on. I forgot to put the point in MOT_BAT_VOLT_MIN .
The point that surprised me is that I did autotune;
My Autotune flight logs:
1)https://drive.google.com/file/d/1sXvurnfTRtqgZFJ_82SC9XQBTM-Y79-d/view?usp=sharing
2)https://drive.google.com/file/d/1eLZ4YS44V2PdKI5wZLyq6c6CF2O3-bvH/view?usp=sharing
3)https://drive.google.com/file/d/1gi_LsJyd-g6Uc3GGotT9NgY0jWG03v11/view?usp=sharing
Last time I landed in Loiter mode. Maybe that’s why he didn’t lose the settings?
On the site, it said turn off the autotune channel for testing, then open it, did I misunderstand that? 2 days left to the competition and I couldn’t test fast autonomous flight

dkemxr · September 10, 2021, 2:27pm

The tuned values won’t be saved unless you are in Auto Tune when it’s disarmed. Don’t switch out of it. When it completes land and disarm, simple as that.

But you need to fix the vibe levels and configure the Dynamic Notch Filter before running Auto Tune anyway.

kcukekmkc · September 10, 2021, 2:31pm

How can I fix the vibration level? I can only think of a carbon propeller and there was no visible vibration on my previous flights.

dkemxr · September 10, 2021, 2:39pm

What Flight Controller and how is it mounted? What frame?

kcukekmkc · September 10, 2021, 2:40pm

Pixhawk 4
Brottherhobby tornada t5 pro 640kv
carbon frame

dkemxr · September 10, 2021, 2:41pm

How is it mounted? Is the frame rigid or thin CF?

kcukekmkc · September 10, 2021, 2:52pm

CF 1.5 mm

dkemxr · September 10, 2021, 2:56pm

Yea, thin CF. 3rd time, how is the FC mounted/attached to the plate? Double sided tape, foam tape? You will probably need an antivibration mount of some type. Is that battery plate mounted to the same plate as the FC with stand-offs?

kcukekmkc · September 10, 2021, 3:02pm

We used 3m foam tape. We mounted the plate on which we will put the battery, with the help of a spacer, on the plate where the FC is located.

dkemxr · September 10, 2021, 3:07pm

I think that will be a problem even with an anti vibe mount but I would try one anyway. Foam tape isn’t going to work.

kcukekmkc · September 10, 2021, 3:14pm

It seems I can’t fix the vibration level right now, should I Autotune it? I’ll fly it now I hope it’s okay

dkemxr · September 10, 2021, 3:15pm

No, you should configure the Dynamic Notch Filter. Then run Auto Tune.

Dynamic Notch

kcukekmkc · September 10, 2021, 3:18pm

Thank you so muchh, i’m doing it now

dkemxr · September 10, 2021, 3:20pm

All you need to do initially is set INS_LOG_BAT_MASK to 1 and make a short hover flight in AltHold. 1 minute is good. Post that log if you like.

kcukekmkc · September 10, 2021, 3:43pm

I guess it will be a throttle based setup.
INS_HNTC_MODE =1
INS_LOG_BAT_MASK = 1
INS_LOG_BAT_OPT = 0
I did INS_LOG_BAT_MASK = 1, INS_LOG_BAT_MASK = 1; Or should I just do this?
I’m going to fly now.

dkemxr · September 10, 2021, 4:35pm

Just do what I said. The configuration comes after analyzing the log.

Quadzilla · September 10, 2021, 5:06pm

Is it possible the battery is hitting the FC?

Integrated vibrations isolation" Normally no need to use anything except 3M tape.

kcukekmkc · September 10, 2021, 5:12pm

I didn’t see the article, I did as I said but I made minor changes in the drone and it was better.
https://drive.google.com/file/d/16F02DZQCLatMWqmozMvxQsGqMI6_6qxk/view?usp=sharing
Also, I will autotune tomorrow, then autonomous flight, my last day for the competition.
I have two questions, I would be very happy if you answer.

I have a second battery of 6000 mAh. This battery is heavier. If the auto mode does not end with the first battery, will it be a problem if I do the other axis with the second battery?
In the articles I came across on the forum, I read something like “I need to upgrade to beta version for speed”. Is this for racing drone, my drone can reach a maximum speed of 60km/h= 16m/h according to eCalc site. Can’t I reach these values in version 4.07?