Unstable flight path

ArduCopter
1

Hi
I’m using pixhawk orange cube and I recently tuned my aircraft, but my UAV is not performing stable flights. It is shaking on position hold mode and also it’s drifting from it’s position. I’m attaching a log file and also the flight path which it followed.

IMG_7524.JPG - Google Drive, 2024-03-13 12-55-47.bin - Google Drive

2

Tune it methodically to make sure you do not forget or skip any step.

3

I guess you Auto Tuned it w/o setting some other parameters first like the Notch Filter, these which are at default:
PSC_ACCZ_I,1
PSC_ACCZ_P,0.5
And read this as they are at default also: Setting Motor Ranges

Position Hold should be deprecated. Use Loiter.
And you should have current logging.

4

Actually I tuned it and had around 20-25 flights but after that I started facing these issues. The UAV started following zig-zag path and also it was vibrating a lot. In previously executed flights, it was stable and was executing missions without any issue.

5

I would blame it on hardware fatigue due to vibrations. Make sure all screws are tight and tune it methodically to reduce at least the self induced oscillations. Then it might work a couple of more years without issues.

6

I did check the hardware before flight and everything was perfectly fitted. There might be some other issue, and it could be some issue with the firmware.

7

The firmware did not change, why do you think that the firmware might be the problem?

8

Because I never faced such issues with any of my copter earlier but with this one and another one too, I faced the same issue. And these issues started at the same time, that’s why I was thinking in this direction that there might be some issue with the firmware.

9

Do all copters use the exact same firmware?
The ones that work use the same FW as the ones that do not?

10

Yes, mechanically each is a copy of other. All the electronic components were same and the firmware was same too, yet I faced this issue with only two copters.

11
  1. The firmware is a (100% identical) digital copy of each other.
  2. The configuration has calibration values that are chip dependent. The chips are different, so the configuration must be different for the system to work properly.
  3. The hardware is impossible to be 100% identical (laws of physics)

And you are thinking this is a firmware issue?

1 Like
12

You either have and hardware issue or a configuration issue.

You say the hardware is similar.
How did you make sure that the configuration is similar? What was the method you used?

13

Did you changed the firmware or something else after the first 20-25 flights without the issue? The firmware will mostly not changed by ghost.

14

Yes, I’m thinking in this direction only, because every other part was manufactured by the same machine and it was also assembled using the same methods, so how can it starts behaving like this even when no-one has touched neither the hardware nor the software.

15

No, I didn’t make any changes in the firmware. I used the same quad with same parameters without making changes to anything.
Can it be an issue with the tuned params of the quad?

16

You did not answer my questions.

17

I did answer your question.

18

I don’t think that your last answer to @amilcarlucas is helpful.
Go back to all of his questions and answer these.
It is you who wants to get help.
If nothing changed to the drone, no firmware change, no hardware change, no parameter change and before everything was good tuned and after a while it is start vibrating that probably some mechanical part is not as good as you think

1 Like
19

These two questions are still unanswered. I need details!!!