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FPV Manual Mode -- Flight #6

Chaosrider

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OK, that was an unwanted adventure!

I tried tightening down the screws for the right stick as well, to see if that helped. I wanted the stick to tend to stay where I put it, unless I affirmatively moved it. That sort of worked, but not very well, and not the way I wanted it to. On balance, a failed experiment. As usual, I cancelled the low battery RTH. A little bit after that, I decided it was time to come home, and I hit the Brake to go back into Normal mode.

And that’s when it got weird. The right stick didn’t work! Full right stick up, and no forward motion. Moving the right stick up and down didn’t seem to produce any result at all. I finally hit the RTH myself, and it started to climb to its RTH altitude which, in that low battery condition, was seriously unhelpful. But it did then start to return home, in a random walk sort of way. Eventually, it said, “No Power. I’m landing right here!”

Not good!

This is all in Normal mode at this point. Through some combination of commands that I can’t remember, I got it back to the end of the driveway…from about 1500 ft away…and got it to land with little vertical velocity, but skittering around a bit. Some of the lateral control on the right stick had come back, but the friction made it feel unnatural. After touching down, the drone gently drifted into a sagebrush on the side of the driveway, and stopped. I killed the motors, and went and got it.

No damage of any kind, the drone is fine. In conventional aviation, it would be classified as an “incident” rather than an “accident”. It certainly wasn’t a crash, but it was highly undesirable.

What would cause the ineffectiveness of the right stick after going back to Normal mode?? It worked fine before I switched to Manual at the beginning of the flight. What would cause that? The tightening of the right stick screws was the only different thing, so it must have been caused by that…but how? Through what mechanism?

Obviously, I’m going to loosen those screws back out, but I very much want to understand the causal chain of the control failure. It once again told me to tighten the F2 screw on the throttle, so I’m going to do that, But how does it sense that that needs to be done? And why does it “need” to be done? I’ve been pretty happy with the way the throttle behaves. But The Machine can’t be wrong…

Starting with the over-simplification that the left stick controls vertical speed, and the right stick controls forward/backward speed, I started to get a sense for the conditions where that doesn’t work well, and adjusted my responses accordingly, with a mixture of left and right stick to produce the desired resulting motion.

Before switching to Manual initially, I set the camera to 10º up, and left it there. That was both useful, and annoying. I immediately adapted to the screen view being my attitude indicator, which was helpful, but I didn’t like the way the attitude bounced around as much as it did. On balance, it will be useful to do that, at least for a little while yet.

I’m also starting to get some intuitive sense of this “rate” business, and so far, there’s not a single thing about it that I like. But it is what it is, and I’ll get better with it over time.

Turning left or right still seems sluggish to me. Paying more attention to coordinating the turns helps, but I’m still getting the sense that it’s thinking about whether or not to do what I tell it to do, when I initiate a turn. Any idea what might cause that, or better yet, something that I might do to fix it?

It occurred to me that there might be a kind of Heisenberg Effect going on here…you can’t precisely know both the position and momentum of the drone at the same time!

The most disturbing thing about the flight was the failure to properly return to Normal mode after hitting the Brake, in terms of the right stick response. I’ll loosen those screws back out, which should cure the problem, but I’d sure like to know what causes it. Could it be related to the “Control stick error” message that I still get when starting up? It always goes away quickly when I liftoff, but there’s something not right there. What might that be?

Never a dull moment!

1654628459585.png
 
My Manual mode skills gelled again overnight. I won't be providing any more individual flight update threads, unless something unusual happens.

Today I did a couple of laps up and down the canyon, a bit faster each time. On the final run home, I was at full throttle, and saw 79 mph. My objective was to do these laps at 300 - 400 ft ATL, and I mostly did that.

I'm still having a bit of a problem with losing altitude during the 180º turns, although not as bad as I used to. On a fixed wing aircraft, I'd add a bit of power, and pull the nose up a bit, to stay level in the turns.

Is there any reason to think I should do something other than that with the FPV?

Next flight will be the same thing, but going faster sooner, and lowering the altitude range to 250 - 350 ft ATL, hopefully staying closer to 300 ft in the process.

When I can comfortably do those laps at full throttle and 100 ft ATL, I'll need to decide whether the additional speed is worth the "tax" of losing all the automatic stabilization. Maybe yes, maybe no. I won't know 'til I get there!

:cool:
 
No clue.

It wasn't posted there by my choice. I went to the FPV forum to post it. I have no idea how it got in RC-Pro.
 
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No clue.

It wasn't posted there by my choice. I went to the FPV forum to post it. I have no idea how it got in RC-Pro.
No idea ether other than you just hit the wrong forum.
Repost it there.
 
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