On my AR wing Pro i can not do a proper flare while landing if i am in FBWA mode. I use pitot on it.
How do i prepare for landing? I usually do a long final and glide down to the runway. Maybe i give a little throttle during gliding if i am too low.
When it is time to pull up, there is little to no effect (ithink it because of stall protection). The wing continues sinking and “splat” on the runway.
When i land manual i am able to flare.
This is my best wing, flyes well in all modes…
It’only about the flare.
Have you performed an autotune and set the AIRSPEED_MIN and especially the SCALING_SPEED to a realistic value for your aircraft (= the speed at which you perform the autotune)?
Yes i know the wiki, but is is good to read again.
To me speed scaling is about scaling PID. Right?
Seems like my issue is that my wing glides about at the minimum speed i set for my wing. So there is no room for pitch-up as i am too slow, and tecs won’t let me go up.
Is this a logical reasoning? Does it makes sense?
Will check scaling speed on this model anyway. It is old enough for me not to remember the setup process i did…
The TECS settings are very important for all autothrottle modes. But you wrote at the beginning that, in contrast to manual mode, you cannot really initiate a proper flare in FBWA mode despite pulling the elevator stick fully. I therefore suspect that the scaling speed parameterised for the autotune was too low. The TECS parameters has no influence on FBWA, as you operate throttle in FBWA.
Should AIRSPEED_CRUISE = SCALING_SPEED as according to the wiki both are working around the same thing? I’m curious why there would be two parameters for the same information.
The results obtained in the Autotune are conditioned by the airspeed and are valid for the airspeed at which the Autotune was performed.
When the aircraft flies at different speeds these results are scaled to remain valid.
SCALING_SPEED is the speed at which the system assumes the Autotune was performed and on which it will perform the scaling calculations so that the results of that Autotune remain valid at other speeds.
I’ve been thinking about it more and I agree. So the two values may start the same but I can see where you may change AIRSPEED_CRUISE over time or need.
I would also be interested in this topic.
Flying-wings are supposed to lift the nose based on motor power and drop the nose without it.
You may simply have no pitch authority left when you try to flare. Too slow and too nose heavy.
I rised scaling speed to 65km/h and did autotune around that speed again.
I still can not flare in FBWA flight-mode during landing.
I can flare in manual, the higher the speed the better the flare.
What i do during landing is a normal final at 0% throttle, the wing glides down at trim speed and between 1.5/2 m/s. When i approach the ground i start pulling on the elevator untill it slows down and “stalls” close to the ground.
In FBWA modes, this is the same, but when i pull up, it does nothing and it SPLAT on the runway
What i think is: FBWA doesn’t provide the same surface movement as manual mode for the attitude/speed during final moment of landing. Probably more speed would help.
I will experiment with faster approaches or different settings of STAB_PITCH_DOWN and see if it gives me a bit more of speed to trade during flare.
I confirm CG is on spot and i have surface autorithy during manual mode flights and landings.
That’s not nice. I would take STAB_PITCH_DOWN out. And can you link a *.BIN log file of a landing with FBWA and manual mode so that we can take a closer look?