Hi,

The other day I tried the POI feature on my new Phantom 4.
I was sadly disappointed when I watched the video. The phantom starts circling the POI, but the motion of the yaw axis is jerky, meaning that you can clearly see the yaw being adjusted in bigger increments every few feet, instead of a smooth continuous adjustment, making the footage unusable...

The radius was about 190 meters, speed was relatively high, to complete the full circle in around 3 minutes. Video settings were 4K 30fps.
Below is part of the resulting video, where the problem is clearly visible.

Any idea what causes this and how it can be fixed?
Altittude drops when moving in one direction and releasing the controls are also recurrent...

https://www.youtube.com/watch?v=w8mURY7ko8o

Hope someone can shed some light! Thanks!

Looks pretty darn good to me.

Rodomontade Posted at 2016-5-24 17:53
Looks pretty darn good to me.

If you watch whole video you can clearly see the yaw being adjusted in big increments, every so often, making it very distracting...

Hello logikdrive,does this issue happen when you select a smaller radius and lower speed? Also,was it strong wind at that time?

Looked reasonably good here. What are you playing video back on ? 4k can be quite demanding for smooth playback.

DJI-Paladin Posted at 2016-5-24 18:42
Hello logikdrive,does this issue happen when you select a smaller radius and lower speed? Also,was i ...

Hi,

There was some wind.
I will have to try with a smaller radius to see how it behaves.
Just checked the record, Phantom speed was around 9m/s.
Thanks!

Aardvark Posted at 2016-5-24 18:46
Looked reasonably good here. What are you playing video back on ? 4k can be quite demanding for smoo ...

I am playing back on my 2015 macbook pro and it's perfectly smooth.
Also downsized to 1080p for youtube upload. The footage is smooth overall, only the motion of the yaw axis is not.

JoseTorre Posted at 2016-5-24 19:15
I am playing back on my 2015 macbook pro and it's perfectly smooth.
Also downsized to 1080p for yo ...

So when you play it in your Mac, everything works well and the yaw issue disappear?

i m assuming the copter is otherwise setup properly (calibrated, props unbent etc. etc.)?
like you said, wind is also definetely a factor for Phantoms turning smoothly.. they struggle at some point.

But I think the true issue is the large radius + higher speed. keep in mind that the logged in POI at such a radius is really 'small' and requires very precise / smooth turning.
imagine an object 10m in front, and then drone rotates a few degrees = POI barely moves from center.
imagine an object 200m in distance, and then drone rotates a few degress = POI now halfway to edge of frame.
I m pretty sure you have simply reached a radius that requires drone to fly / turn / maneuver more minutely/precisely than it is capable, esepcially at high speed. problem goes away when you decrease radius / decrease speed, yes?

that being said, it s a huge radius (I prefer large ones too) and the result isnt that bad at all.
did you try warp stabilizing it to pans? will probably fix it..

mine does same thing, pretty sure that's just how it is.

Mine does same thing

Sebb Posted at 2016-5-25 16:56
i m assuming the copter is otherwise setup properly (calibrated, props unbent etc. etc.)?
like you s ...

I agree with this, try a smaller radius and less wind.

I think it looks fine too. The hype that surrounds these little technological marvels, coupled with the enthusiasm of the operator to do "More for less", can lead to unrealistically high expectations. It is important to note that for all its capabilities, the phantom is a  $1300 consumer level quad. It is nothing short of amazing and I absolutely love mine. It does however, have limitations, and I try not to let that disappoint me to much. I don't know what the exact specs are for yaw correction of the gimbal. looking at mine and manually introducing yaw movement, I can see it's probably 5 to 10 degrees, maybe less, before it hits the stops. Any instability in the airframe about the yaw axis will need to fall within that arc of correction. I'm just speculating here, but it seems like the airframe yaw movement is so slow that the gimbal is allowing a slight amount of drift before slewing back to the crafts central axis. The gimbal is always catching up to the airframe. This would not be a problem with a 360 dregree pan gimbal. As usual, most problems can be overcome by throwing money at it.