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  #31  
Old 12-03-2017, 04:23 PM
tridge tridge is offline
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Quote:
Originally Posted by flexible2g View Post
I am all in for what they are trying to accomplish. I can find nothing, like this hovering without vectoring. Elevons can not control yaw.
Then you just haven't tried very hard in your searches. These are standard vehicle types in the world of autonomous vehicles.
I did suggest you lookup the wingtra. Here is the direct link: https://wingtra.com/
There are many thousands of others.
Elevons control yaw fine, both in the real world and in realflight
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  #32  
Old 12-03-2017, 04:28 PM
tridge tridge is offline
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Quote:
Originally Posted by csgill75 View Post
https://youtu.be/o_95BNzNWnM

In that video is that aircraft I posted about holding a hover with only elevons. It seems to work. It may be using variable thrust as well but I am not sure. The op may have more information on how exactly it works.
The control system is very simple:
  • roll is from differential thrust on the two motors
  • pitch is from elevon pitch
  • yaw is from elevon (what would be roll in fixed wing flight)
  • climb is from average thrust
The key for the airframe is the very large elevons to give sufficient control. Also a willingness to pick up the aircraft off the ground when it falls over on landing :-)
Detailed discussions of the ArduPilot implementation of the control scheme is here:
https://discuss.ardupilot.org/t/dual...lsitters/15302
plenty of flight videos linked in that discussion
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  #33  
Old 12-03-2017, 06:03 PM
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flexible2g flexible2g is offline
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differential thrust

You left out one very important thing differential thrust. Add differential thrust to you're model and it will fly great.
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Last edited by flexible2g; 12-03-2017 at 06:07 PM.
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  #34  
Old 12-06-2017, 05:15 PM
tridge tridge is offline
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Quote:
Originally Posted by flexible2g View Post
You left out one very important thing differential thrust. Add differential thrust to you're model and it will fly great.
yep, though it was more a matter of terminology. For a tailsitter in hover we (the ArduPilot community) call yaw the axis you get with elevon (ie. body frame roll). We call the axis you get with differential thrust roll. This is because with ArduPilot in control it makes the users inputs map to those of a multicopter when hovering, and changes to fixed wing control axes when you switch to a forward flight mode. In RealFlight8 the XPlusOne does the same thing in Hover mode.
So I thought you were saying that roll about body frame doesn't work, which it obviously does :-)
I'll add in some differential thrust on rudder in the CatManual model. For the ArduPilot controlled model we use two completely separate channels for the two motors, but that would be rather inconvenient for a manual pilot, so best to mix it with rudder stick.
Sorry for the misunderstanding.
Cheers, Tridge
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  #35  
Old 12-06-2017, 06:27 PM
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flexible2g flexible2g is offline
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thrust, deferential

Correct on all counts.
In rf, you should have two single pods/motors, not symmetrical.
Both can be set on ch 3, with on also linked to ch 4. Should fly great.
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  #36  
Old 12-06-2017, 07:39 PM
tridge tridge is offline
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Originally Posted by flexible2g View Post
Correct on all counts.
you should have two single pods/motors, not symmetrical.
why is that?
I've done it both ways and they seem to behave the same (except for a possible difference in the current reporting)
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  #37  
Old 12-06-2017, 08:02 PM
adrenoline 60 adrenoline 60 is offline
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When quoting Channels, are we all referring to the same Controller Mode?
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  #38  
Old 12-06-2017, 10:39 PM
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flexible2g flexible2g is offline
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Mode

Now days, in the USA, we use mode2, with exception, some pattern flyers like mode1.
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