Mapping glitches - flying off course and gimbal issue
This mission was not the first one for the day - it was about the 3rd or 4th. The mission directly beforehand went fine (it was 90 degrees rotation to this one). There was minimal wind around, even flying at 100m it was steady hovering.
I've got a link to the video here as it will make more sense with timestamps:
Start of video: The Mavic Air had just done the first two runs without issues. You can see between 0:00 and 0:10 that it starts to go off course on the mission view. The lines were running parallel to the road, but just off centre.
0:28 to 0:45: you can see the drone visibly start heading off course on the video as well.
0:46 to 1:00: visible issues with the gimbal doing something strange
1:19 to 2:06: it flew the path, but didn't actually take any photos along the way
2:22 to 3:23: it starts off course on the next run and continued to get worse, crossing over the path of the next run
3:24 to 3:34: it shows on the video that it's making a turn, but mission reference is a long way from where it is on the map. It ended up over the other side of the main road, then slowly went back to the next run and finished.
Any thoughts on what might have happened? I had line of sight the whole time and great satellite locks etc. As above, there was minimal wind and when I did a hover test up high it wasn't moving around. I repeated the mission a few minutes later and it had a similar issue where it appeared off-track, turned early etc. I repeated again and all was good on the 3rd attempt.
What I thought should have happened:
1. If it fell short of the end point, it should re-run that particular path that it had issues on
2. When going off track, it should recognise that and somehow go back to the start of the path and do that bit again
3. If it does not take photos along one path, it should re-run
Thoughts? I've had no other issues with the mapping before.
Comments
7 comments
Here is an image of the Airdata flight log.
It looks like the winds aloft must have picked up at about 10 seconds in to the video (as a headwind). It appears that the mission was programmed to run at 30 km/h and the rest of that segment it is struggling to maintain 20 km/h. By 1:30 you can tell it has a tailwind as it is trying to catch up and almost reaches 50 km/h. Moral to the story, with a small airframe like the Mavic air you need to program the mission to fly slower if it is possible the winds aloft will be gusting so much (to it has extra flight performance envelope to maintain course).
Great, thanks for the analysis, noted for next time :)
Had an almost identical issue last weekend with orbit.
Not much wind at all in fact and a/c (mavic pro) managed to RTH quickly and without effort ‘into’ the prevailing wind when I aborted as it was struggling badly holding the mission orbit and completely off course. No data saved, (James how did you screen record?)
Jim, you say slow down the mission speed, I assumed that a higher mission speed would be more urgent and responsive to higher wind speeds, are you saying this is not the case? Thanks.
Flying slower leaves the onboard flight controller more performance envelope to deal with wind and other variables.
Wanted to leave my example of what may be an issue:
The center of the school is not in the center of the view for the entire rotation. My speed was 10 mph with Mavic Air.
https://www.youtube.com/watch?v=xVGwAe6DM8I&feature=youtu.be
https://app.dronelink.com/robert-silvers/first-test/plan/cC9D0AFqH3u9umI99Kbu/GDx2LB3jEsEFVtTk2n3k
See this thread:
https://support.dronelink.com/hc/en-us/community/posts/360034749773-Seeming-to-have-a-Heading-error-
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