I am using my Iris+ for about half a year now. Without any major issues. All is running smooth.
There is just one annoying issue that with a 2-axis gimbal (Tarot) I always need post video stabilization as there are strongly visible yaw movements.
I have seen other raw videos on youtube and it seems that some persons get much better yaw stability.
I tried tuning the PIDs with minor success. Basically I am able to tune down the amplitude of the yaw movements, change their frequency, but so far have not gotten them to a level which I found appropriate.
Anyone having good experiences with that?For me it's hard to accept that I would need a 3 axis gimbal. I still hope it can be fixed by a good tuning.
Currently my PIDs for yaw are like that:
rate P 0.7
rate D 0.008
rate i 0.03
stab P 10.0
Anyone having better values? Anyone having a good idea on the tuning strategy? Less stab P and tryin to solve it via the rate values?
I think that's a fairly common problem. Most people I've asked about it (especially professional aerial photographers) recommend going at the controller rather than the PIDs at first. A 40%-50% expo curve on your yaw input should reduce the yaw twitches significantly, the remainder seems to be tuning and piloting skills. I had the same problem and managed to get rid of it with that combination.
This is all assuming you're not flying in a mode that depends on the compass for heading, I've given up trying to get yaw-stable video in LTR or AUTO with a 2-axis gimbal.
I did not know that the controller will have an influence on yaw stabilization even if I don't touch the stick. So the control loop depends on the controller settings?
No, I'm talking about the unintentional yaw that happens when the expo curve is flat. It's unforgiving, so even the slightest unintentional left-right movement on the stick when applying throttle will result in some yaw movement.
If you are not touching the stick at all and the yaw is still twitching (not oscillating like a PID out of tune) the expo curve won't help. I thought I was pretty good at not giving those tiny unintentional yaw commands when on the throttle, but I was proven wrong when I changed the expo and things smoothed out.
Hi Erik, I see it like this:
Along the X and Y axis the quad needs to tilt in order to manoeuver around. Those system immanent and necessary movements you don't want to see on your camera, so you need at least to stabilize those two axis.
Yaw movements are intentionally. The quad itself with its control loop acts as a stabilizer. So theoretically there is no need to add stabilization around the Z axis, if the quad would stabilize it perfectly.
Well, here's a demo of what I came up with using the Tarot 2D. No post-processing. The nadir shots are the most telling, even tiny twitches will show up very obviously.
And here's the same pilot, same craft, with a flat expo curve.
Can you share your PID settings for YAW?
You were flying that all in manual, so no auto, loiter, position hold?
Stab Yaw P: 5.00