Problem between Manual / FBWA and LOITER / RTL.
AUTO_TRIMM = 0
In MANUAL and FBWA, the model (GLIDER) flies horizontally.
In LOITER and RTL, the model flies with an increased pitch angle
(stably at high speed downwards).
How can I get the model to fly in LOITER / RTL the same way it
does in MANUAL / FBWA?
I couldn’t find a parameter for this in the documentation!
Best regards
We will need a .bin log file.
I would suspect use of trim in the rc radio.
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After resolving various problems, here is the LOG file.
Visually, there is a clear difference between the circling of MODE RTL, LOITER and FWBA (by hand).
A higher sink rate is advantageous in MODE RTL, since FASTDOWN is not available there anyway.
However, this is a disadvantage in LOITER mode.
In thermal areas, a higher angle of attack can always be flown than under normal conditions!
Therefore, a higher pitch angle should be specified in LOITER MODE than in FWBA MODE.
Are there possibly different airspeed specifications between RTL/LOITER and FWBA, and how can this be changed?
Problem: I can’t upload a ZIP file; is it possible to shorten the LOG file (< 8MB)?
Use one of well known file sharing services.
- Set ARMING_CHECK to 1
- I would recommend using a proper airspeed sensor for gliding.
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Hi Werner,
I’m not sure if I understand you correctly. Are you saying that the aircraft flies at a higher angle of attack in RTL and Loiter than when you fly it manually or in FBWA?
If that is the case, it is probably due to the different speeds at which they fly.
FBWA does not control speed at all, only attitude (pitch and roll). The pilot is responsible for ensuring that sufficient thrust is provided so that the aircraft can fly at the specified attitude.
Unlike FBWA, Arduplane controls thrust and/or speed in RTL and Loiter. Flight Modes — Plane documentation
It’s best to upload the log file to cloud storage and link to it.
As @LupusTheCanine wrote, don’t fly with the ARMINIG_CHECK function switched off.
Rolf
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Thank you for your feedback.
A speed sensor would certainly be advantageous here, but it’s complicated to install on small, ready-made models. ARMING_CHECK has been changed to “1”, but this is probably only for safety reasons.
Rolf:
The problem here is that the models in LOITER mode drop too much.
On the contrary, the models descend faster in RTL and LOITER modes (smaller angle of attack) than in Manual and FWBA modes. The speed difference is significant.
The difference in the regulations between FBWA and LOITER has now been established.
What is meant by “automatic” is unclear. It can’t be a speed control system, because there’s no target of speed and no actual value of speed.
The only possibility I see, if the problem is related to speed, is to drastically reduce the maximum speed – AIRSPEED_MAX = 22 m/s to 8 m/s.
Is this the right approach?
If there is a will, there is a way.
The miniature probe should have been printed in resin but printing with 0.2mm nozzle and sealing with very thin CA worked well enough.
You have enabled use od synthetic airspeed by TECS. You must correctly configured AIRSPEED_* parameters to match your aircraft. With correct configuration TECS will be able to maintain your desired airspeed. IIRC FBWB linearly maps speed range to throttle position, so the solution might be as simple as moving the throttle stick back.
Highly unlikely. It is impossible to tell anything without logs.
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Please read through the wiki on this first.
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First, here’s the link to the log file.
Okay, now everything is clear. Automatic mode wasn’t enabled.
Thanks for your help!