Drone heading not maintained during flight
Two days ago, I flew a mission with the latest Beta 2.2.0 (142) and reported an issue I had with it. I deleted the dronelink app and reinstalled the released version 2.1.0 (140) and flew a mission I fly most every day, but with some path changes. That mission flew as expected, but I wanted to make a couple of minor tweaks to the gimbal angle at one marker and a drone heading change at the very end of the mission so the drone would face me as it lands.
So today, I flew the amended mission and experienced something it has never done before. At marker 9, the drone heading is set on a 270 degree heading from the path while the drone flies in a square around an area that is being repaved. The first leg of the square went fine and the camera faced 270 degrees. It made the first and second turn and the path stayed on 270 degrees. However on the third turn, the drone heading started out at 270 degrees but changed to ~355 degrees off the path by the time it rounded the fourth turn, pointing nearly straight ahead. It remained on that heading for the duration of the flight, almost as if it was executing the mission change I had made 3 markers further into the plan which had its interpolation set to curved. All other markers from 9 on had their interpolation values set to none.
I took several screen shots of the mission to show the relative position of the drone heading on the map as it proceeded. As you can see from the mission plan, no heading change was made after marker 9, so the drone should have stayed at 270 degrees off the path until marker 13.
Also... The airdata upload from today did not draw the path as it usually does. I included a screen shot of it today and the day before for comparison.
Shared Plan
https://app.dronelink.com/6377/failed-missions/plan/CRHJBiqLSYLb9w1qZl4S/YgJzcgillastZRdnQDa6
Comments
12 comments
One more screen capture. This is where the drone was actually on the correct 270 degree path heading after marker 9.
You're right, I copied your plan and to make it do what you wanted, I was forced to copy marker 9 to make a 10 to put in the bottom of the last square.
So as to reiterate.
Then I created a completely new plan and took it on the same trip but I didn't encounter that problem.
Is very strange.
Correction:
I did not notice marker 13 where there was an interpolation on the direction of the drone.
Read below
So the last change I had made to the plan was at marker 13 in which I set interpolation to curved. I ran the mission in preview mode and observed the same flight path as it did in real time so I changed the interpolation for marker 13 to none and the problem went away. Something to do with the interpolation setting.
That is what interpolation means. If you won't want it to face forward until marker 13 you need to disable interpolation. Moving this out of bug reports as it is expected behavior.
I understand, but there are 3 markers between 9 and 13 all of which have interpolation values set to none. I would have expected the marker 13 interpolation value to begin at marker 13 not marker 9 which is what it appears to be doing.
Ehm no Larry, on markers 10-11-12 you set only the gimbal and not the direction of the drone so that marker 9 and marker 13 are interpolated.
Only if you set the direction of the drone in any of the above markers, the 13 will not be interpolated.
And the farther the two markers to interpolate are, the better you will see its effect.
THIS IS NOT A BUG is how the interpolation works.
Oh... So you are saying that interpolation only affects values that are set in a marker such as heading, speed, etc. The fact that the other markers have interpolation set to 'None' does not apply in this case because they only set Gimbal pitch? And further, the marker in which interpolation is set does not affect markers after it, but rather affects the markers before it. Wow, this is so not how I thought they worked. By chance is there a writeup somewhere explaining interpolation?
Let's wait for Jim to answer.
Yes, however I have noticed in my tests, that the interpolation exists between two similar settings and works between the before and the after (start and end).
Between two markers where the direction of the drone is set or between two markers where the direction of the gimbal is set, or the altitude, etc.
Basically, you have to give it the two values between which to do the interpolation.
Interpolation applies to the circled items:
One thing to note is we do not support interpolation between Drone Heading / Gimbal Orientation and Point of Interest right now.
Interpolation at a marker means, smoothly interpolate the values specified at the current marker from whatever their previous values were so that by the time the drone gets to the marker in question, the values that you have specified have been achieved.
Actual documentation, or lack thereof, is a sore subject. For now, the answer is, just run a mission preview and see for yourself what effect various settings have.
Please clarify... "we do not support interpolation between Drone Heading..." This does not make sense when you circled them above. Did you intend to say 'only' instead of 'not'? If multiple items are specified, does interpolation affect 'all' of those items? I will do some more testing now that I have a better idea of what to expect. Thank you both for shedding light on this.
If you put a marker with a Drone Heading and then a later marker with a Point of Interest (which implies a drone heading), it will not interpolate between the drone heading on the first marker and the implied drone heading on the second marker. Same goes for the implied gimbal pitch.
If you have two markers with Drone Headings and/or Gimbal Pitches on both, interpolation will work. Again, talk is cheap. The only thing that really matters is what the previewer shows you as that is actual reality in the code.
Got it. Thanks again for clarifying. Hard to know when a bug is a bug if you don't understand the normal behaviour. I'm on it...
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