So this is the video from one of my flights with my home built 5" at the weekend.
You’ll notice there is an almost constant “jittering” low frequency vibration in the image. Not Jello. In fact I don’t think there is any Jello to speak of.
I’d like to clean this jittering out… I’m assuming it’s something to do with the flight characteristics… Is this something that adjusting PID tuning can fix?
I’ve avoided PID tuning completely so far as though I do understand control theory I’ve no idea really where to start with Quad tuning. I looked at the Chris Rosser videos, but he goes straight into black-box and to be fair I struggle to work out which black box recording matches which flight. It feels like enough to get a quad in the air, never mind worry about how it flies and it’s only really in the after-videos that I notice stuff like this.
Runcam Hybrid 4K. and yes… though it’s less noticeable in analog.
I did also see it in the latest videos with my Gecko, which has a Foxeer Mix on it. This only after upgrading Betaflight and losing the custom tune the previous owner had on it. It was smooth as silk before then.
That rules out my initial thoughts that it might have been an unwanted artefact of image stabilisation. I see a similar effect if I use IS on my Runcam5 HD camera.
Ideally need to look at the blackbox logs really. Wipe the logs, record one simple flight of cruising around, plus some hard moves like a few rolls and flips so you can see how it responds to both small and large inputs.
Stick the file up here and maybe someone can take a look? I’m no expert, but have a rough idea of what too much/little P/D etc looks like.
So… I have a directory of black box files from my 5", god knows how old they are. The flight controller has inbuilt flash, this is not SD card contents.
I have loaded stuff like this before into the black box viewer, but could not work out which file was which. The “all” file seemed to contain all the other stuff… It confused me.
The guides I had found just said helpfully… “load the black box file…”, but never how to work out which!
I’ve looked around for a guide to what the hell this stuff is all about before and failed. The fact nothing is timestamped doesn’t help at all.
I suspect that even if these are old files they will show the same problem I’ve seen recently. I think it’s been present on every video.
Wow pitch and roll way overshoot. If you increase d to damp it down, it will work, but make the motors hotter. If it does, reduce p instead. Only my opinion though.
I’ve never really used the sliders. If it was me, I’d reduce the p and retest.
Classically, you’d turn off d-min, put d and I to zero, then adjust p until there is a slight overshoot. Then introduce d to damp the overshoot, then I to compensate for drift. But I think feedforward may mess that up
I do need to do this with my 7" when is hdzero’d eventually.
From one video I can see that you can analyse this even hovering a bit in your basement… Well I can’t do that as I don’t have a basement, but I might try a bit in the back garden later… though it may be dark, lol…
