I believe quadplane firmware will behave that way in QSTABILIZE mode.
I was referring to their blackfly landing process (how it does not bounce). You mean land in QSTABILIZE?
Yes, there’s a simulated landing in QSTABILIZE at 2:27 here:
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Fascinating… I will give it a try.
I can not fly at the moment. I tried using the SITL software with quadplane model and it landed without issues using a waypoint mission that I flew previously with bouncy landing. I then realized, the quadplane model is most likely not modeled after a blackfly.
I looked for the BlackLetpi_EA.RFX file but it is no longer available . Can you repost the correct link to download and try it?
Thanks
That RealFlight model and parameters are here:
It flies for me in QSTABILIZE, QHOVER and FBWA on latest master (and should probably behave the same on stable).
But the tuning could probably be improved in both VTOL and FW modes and the altitude control in QHOVER seems a bit weird.
Thank you very much. I will most likely be spending a lot of time with this model. My plane is out of commission again.
So, you expect the blackfly to land properly without bouncing in QSTABILIZE mode (per the simulation). However, when I do a waypoint mission, how can I achieve a similar outcome? I don’t see any options to set QSTABILIZE when landing (VTOL_LAND or QRTL).
I don’t think there is any way to avoid the landing problem in AUTO modes.
I am having an issue running the simulation. I loaded the mission planner “flightaxis” model with plane. Then, loaded the param file you provided. I then created a simple waypoint mission and loaded it. When I arm, only the rear motors turn and the model flips upside down on the ground.
Since months I wanted to see what vertical acceleration I could get out of my jetwing
bat 5S 40C
5" pitch prop
Qstabilize mode
disk gain attenuation method
0 to 100 km/h in 2.7s
more than 4g initial acceleration
unfortunately qstabilize mode limits average motor output to around pwm 1700 so motors can not spin as hard as they can and speed can not get over 35m/s
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Does it fly OK in QSTABILIZE mode?
Bravo… 
I wonder how much motor PWM margin you need for yaw stability?
Does the jetwing have a rudder?
no rudder,
The right/left balance seems to be very good but the bottom motor is running a little higher than the top one. Stability provided by motors is needed only at low airspeed.
Are you using the no-yaw-torque frame type?
yes, q_frame_type=16
I set the mode to QSTABILIZE and it flew fine. Then, I loaded the waypoint mission, set the mode to AUTO and armed. It flew great (I am thinking I had the wrong config file loaded yesterday). The only problem, as expected, was with the landing. It bounced.
Excuse my ignorance, but can’t the QSTABILIZE landing logic be replicated in the auto mode?
The problem is that the automatic throttle control doesn’t know when to shut the motors down because we don’t have a robust indicator for ground contact. If it were to shut them down too soon, bad things would happen. Best workaround at the moment (that I can think of) is for the pilot to retake control during the final stage of descent.
Not sure if this question has been asked. Using the simulator (or even the aircraft for that matter), when I run a simple 3 waypoint mission and try to vtol land using RTL (Q_RTL_MODE =1), the plane climbs up to about 50 meters regardless of Q_RTL_ALT=15, Q_RTL_ALT=15 as it transitions to vtol and starts landing. And, the transition to vtol is very violent and unstable. It eventually lands. I am using the black letpi params with only Q_RTL_MODE changed to 1.
I may have an explanation for the unstable auto transition. Do you have Q_angle_max=9000 ?
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