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LOSS of CONTROL OVER WATER **EXPLAINED**

Zbip57

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Applying full throttle for a descent isn't needed in order to start the landing [...] a certain threshold which seems to be in the ballpark of a throttle value of -8300 to -8500.
Well that explains that.

Now I'm just wondering how I managed to get down to within 2ft of anything under the Mini, when it was still 25ft higher than my bench?

The circle marks where I believe the drone was at the time that auto-land was triggered. Maybe I was further back than I thought and got within 2ft of that treetop? But if that's the case, how did it manage to not land into the tree when the Mini then descended 15ft in auto-land mode?

Tree.jpg

And I really don't think the Mini was anywhere near that tree. Even if it was, the drone was at least 20ft higher than that treetop at the time.
20ftHigher.jpg

Did you watch the screen recording video in post #58? Any clues in there?

It makes sense that auto-land was triggered when the VPS height showed only 2ft with me holding down the throttle. But I'm still baffled as to why the log showed a VPS height of only 2ft at that point.
 

sar104

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Well that explains that.

Now I'm just wondering how I managed to get down to within 2ft of anything under the Mini, when it was still 25ft higher than my bench?

The circle marks where I believe the drone was at the time that auto-land was triggered. Maybe I was further back than I thought and got within 2ft of that treetop? But if that's the case, how did it manage to not land into the tree when the Mini then descended 15ft in auto-land mode?

View attachment 136503

And I really don't think the Mini was anywhere near that tree. Even if it was, the drone was at least 20ft higher than that treetop at the time.
View attachment 136505

Did you watch the screen recording video in post #58? Any clues in there?

It makes sense that auto-land was triggered when the VPS height showed only 2ft with me holding down the throttle. But I'm still baffled as to why the log showed a VPS height of only 2ft at that point.
The tree is the most likely candidate, unless there was a lot of spray in the air just below the drone.
 

slup

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...Did you watch the screen recording video in post #58? Any clues in there?
Think we see the reason there in the clip ... alot of water smoke/mist coming from that waterfall, could have easily ended up on the sensor & tricked it.

1634149196864.png
 

Zbip57

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The tree is the most likely candidate, unless there was a lot of spray in the air just below the drone.
Think we see the reason there in the clip ... alot of water smoke/mist coming from that waterfall, could have easily ended up on the sensor & tricked it.

I'm really hoping I wasn't stupid enough to blindly back the drone 2ft away from hitting a tree, but I can't 100% guarantee that wasn't the case. ⚠️🌲😳

So I'm going to stick with the spray/mist theory. 😎

I guess that means, when flying in heavy mist, one should not hold the throttle down for more than 3 seconds at a time, and not close to full down.

Here's a video from a different angle showing how much spray/mist was coming off the waterfall.
 

eEridani

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If it's any consolation, sometimes the vps indicator just messes up: note the jump from 30+ feet to 4 as my drone is ascending, T=~210.
Plots.png
 

Zbip57

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Applying full throttle for a descent isn't needed in order to start the landing ... a couple preconditions needs to be met first though.

1. The VPS height should be 0,5m or lower
2. The throttle should in total be applied for descent longer than 3sec.
3. The throttle should sometime during the 3sec be positioned over a certain threshold which seems to be in the ballpark of a throttle value of -8300 to -8500.
I just confirmed this with my Mini.

Man, I was convinced it needed full down throttle to initiate landing. Not so.

Here, with the Mini hovering just off the floor and the VPS system preventing it going any lower, I tried moving the throttle down very slowly, and three times in a row it triggered Auto Landing well before reaching the throttle bottom stop.

Full scale throttle goes from +10,000 down to -10,000. The second test triggered landing at -8,500. I stopped the first two landings just by increasing throttle, and let the 3rd land itself with the throttle released (0 deflection).

ForceLanding.jpg

Thanks for all the help, all of you guys! This forum is so helpful and educational.
 
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