[quote=“tridge, post:742, topic:15302”]
nice! I’d love to buy one
[/quote]It,s going to need testers, and your #1, and just now figuring out the laser and design…
will send a prototype as soon as I have one.and a heads up on parts you will need
[quote=“tridge, post:742, topic:15302”]
yes, it has new transition logic
[/quote]so softer entry into FBWA …video looks like still flipping into FBWA with no forward speed?a slower rotation available in tuning?alt gain is ok for me…
Thanks Rick
It can be tuned with the PTCH2SRV_RMAX and Q_A_ACCEL_P_MAX parameters, but given those also affect non-transition control I think we would probably make it obey the Q_TRANSITION_MS parameter as well, and change target angle based on that parameter. That would allow you to adjust the time for transition appropriately for the airframe.
thanks!
With the “old” transitions I tried to tune Q_A_ACCEL_P_MAX from default 110 000 in 4 steps down to 20 000
and couldn’t see an affect whether in the video nor in the log.[ATT(DesPitch,Pitch),PIQP(P,I,D,FF),IMU(Gyr,Acc)]
Log 43 with 75 000 and 40 000
https://drive.google.com/open?id=0Bxldq38bfbqHNXhQRFMzRDNVUGM
Log 44 with 40 000, 30 000, 20 000 and back to 25 000
https://drive.google.com/open?id=0Bxldq38bfbqHY0U3cEU1UHdpVXM
Regards, Otto
right, it wasn’t effective in the old transition code.
I’ve just made a change to address the issue that @tilt raised about having enough airspeed for mc->fw transition. I’m making it do the transition over Q_TRANSITION_MS milliseconds, defaulting to 2000 for tailsitters. That allows it to pick up some speed before it starts flying as a fixed wing. That also controls the rate it leans forward.
For fw->mc I’m still considering if I’ll do a separate rate limit.
I’ve also made changes to scale the surface gains by throttle, which really helps for FBWA->QHOVER transitions, and helps when descending rapidly in hover.
I plan to release 3.8.3beta4 shortly (probably in the next couple of hours) with these changes.
Cheers, Tridge
Thanks for continuing of the improvements.
Don’t hurry, 
we have very bad,cold weather with snow 150m above ground.
Kind regards, Otto
I’ve released 3.8.3beta4 with the changes for throttle surface scaling and timed fwd transitions for tailsitters.
It is now pretty smooth for me in the simulator, and I hope it will work as well for others!
It especially helps with fast descents.
One thing with beta4 is that it is now important that you set your hover throttle correctly, Q_M_THST_HOVER as this is used for scaling of your gains. So if it is too low then make sure you raise it to your normal hover throttle before flying
While Otto is shovelling snow, we had a rain break 
https://vimeo.com/241394758
2 Flightlogs from the filmes tranistions: 00000034.bin and 00000035.bin
https://www.magentacloud.de/share/ualbgv5hup#$/
We have to adjust PIds a little bit, but all is ok and tranistions are perfect
Rolf
What command actions are executed during this time (Q_TRANSITION_MS ?)
Regards, Otto
So far it is only used for transition from hover to forward flight. What it does is to calculate the desired rate of pitch as the Q_TAILSIT_ANGLE divided by half of the Q_TRANSITION_MS. The idea behind that is you want to spend half the transition time getting to the transition angle. So what you see in flight is the nose comes down from hover over 1 second to the transition angle (default 45 degrees), then it converts to normal fixed wing flight from there. This gives the aircraft time to gain some airspeed, so it tends to produce a better forward transition as the wing has a bit of lift before the normal fixed wing flight takes over.
You can adjust it by changing Q_TRANSITION_MS up or down to suit your airframe.
Cheers, Tridge
The pid adjustment is probably cause your hover throttle (Q_M_THST_HOVER) doesn’t match your actual throttle at hover. If you match them then it should need the same PIDs as before.
actually I think the transitions could still be improved a bit, but it is much better than it was, and I don’t think I’ll change things any more for this release.
Cheers, Tridge
Hi, just a thought… could T/O be sequenced from belly sitting to vertical T/O to FBWA in an auto mode with some time /alt adjustment… another thing I ran into if I armed and moved the craft yaw does NOT like it and it does it,s best to crash…I know, don,t move it after arming
Rick
Thanks for the precise explication of the forward transition
Now, I understand the log of Rolf for this sequence.
Regards, Otto
I’ve created a video showing how I test TVBS and tailsitter models for ArduPilot in RealFlight8
https://youtu.be/H4iqBJ9LGJs
If anyone here wants to play around with the ArduPilot code, or just wants to experiment with tuning strategies then I’d highly recommend getting RealFlight8, as it is easily the best simulator for this type of work in ArduPilot at the moment. You can find more information here:
http://ardupilot.org/dev/docs/sitl-with-realflight.html
This is also a bit of an appeal for help with creating nice 3D models of tailsitters and TVBS for use in RealFlight8 for ArduPilot testing. Creating the physics model in RealFlight8 is quite easy, but creating the 3D graphics model needs skills that I don’t have. So if anyone wants to have a go at that then it would be much appreciated.
Cheers, Tridge
Hello everybody!
I would like to ask you for help. We have been testing our tailsitter and we crashed. It was flying OK, but suddenly motors turned off and it crashed. It was in QHover mode. Altitude hold controller for sure needs some tuning, but such a sudden motor kill is strange.
I looked at log and I saw, that baro pressure suddenly fell down => altitude went up…so maybe the crash was due to the regulator trying to keep the same altitude. But why baro dropped so much? Different air temperature? I have no idea.
Please look and share your opinion.
Log - https://www.uloz.to/!yyTqkbGSvrx9/2017-11-03-repas-crash-bin
I’d be happy to look, but I can’t seem to download the log. Tried chrome, firefox and edge.
Maybe its still uploading?
Cheers, Tridge
yes, that actually works now. Just do a normal quadplane VTOL takeoff in AUTO mode, or a takeoff in GUIDED mode.
yep, sorry, once you are armed it will try to fly, which means resisting “disturbance”. It can’t tell that the disturbance is the planes owner. We don’t have a pilot detector 
Very interresting. I have experience in 3DStudio (Kinetix) and I will have a look at the requested datas for
custom made Models.
Regards, Otto
great!
The recommended tool is 3DS Max, and the RF8 release allows it to work with current versions, whereas previously it only worked with the 2012 version.
I don’t have 3DS max and its quite expensive so I’ve been trying to teach myself blender, as I’ve read that its possible to use that, but my lack of experience with 3D modelling is making it slow going.
In case you haven’t found it, there is some info here:
http://www.knifeedge.com/KEmax/tutorials.php
http://www.knifeedge.com/forums/forumdisplay.php?f=99
I’d also love to do a quadplane model. Leonard has nice 3D models in SolidWorks for an X8 quadplane, and it would be great if we could get that as a model, as X8 quadplanes are a popular type of aircraft for ArduPilot.
Cheers, Tridge
Exactly, very expensiv. I got the old version when I left my company.
Will investigate the link to knifeedge.
If it works, the complexity is no problem.
Regards, Otto
Hi Tridge,
Q_M_THST_HOVER is reduced from 0,8 (with beta2 and former PIDs-Tuning) to 0.6 (with beta4) after reading your post Dual-motor tailsitters - #748 by tridge?
Just to be sure: How is Q_M_THST_HOVER set correctly?
( I thought by hovering in QSTABILIZE and read out CTUN.Thr_out ?)
Regards Rolf