Hi, I cant seem to get my rather heavy TBS Wing to fly quickly enough in Auto modes. The result is that the wing stalls on the second RTL circle above the home point. The handling is fine when I am controlling the throttle in STAB or MAN mode. I have moved the FBWA min parameter higher to no avail. How do I get the wing to cruise faster in AUTO modes?
The throttle response is also “all or nothing” in these modes - no response through 40-905 throttle , then a sudden response to 100%.
Appreciate the help.
[quote=“Jono2014”]Hi, I cant seem to get my rather heavy TBS Wing to fly quickly enough in Auto modes. The result is that the wing stalls on the second RTL circle above the home point. The handling is fine when I am controlling the throttle in STAB or MAN mode. I have moved the FBWA min parameter higher to no avail. How do I get the wing to cruise faster in AUTO modes?
The throttle response is also “all or nothing” in these modes - no response through 40-905 throttle , then a sudden response to 100%.
Appreciate the help.[/quote]
Ummm, some logs would be extra helpful here.
See the following wiki entry for how:
plane.ardupilot.com/wiki/common- … ia_mavlink
Without them it will be hard to see whats going on.
Many thanks for your assistance.
Unfortunately the telemetry module to the GCS was not connected as the wing is so small and weight is everything. I have done my best to download a particular flight where the problem occurred in Auto and RTL mode - I had to switch to manual mode to save the wing. The procedure to download via Mavlink and then attempt to convert the file is really complicated (in my humble opinion), but I have done my best. I have no idea how to read the data I have downloaded as it doesn’t “Playback” as is the case with a normal telemetry stream.
I have tried numerous times to upload either a .bin file, which just gets stuck on the upload process, or a log.gpx file which is not accepted for upload by your website…
The current parameters from the config/tuning page on Mission Planner, following flying the wing in AutoTune mode are as attached in the jpeg below.
I appreciate your help!
[quote=“Jono2014”]Many thanks for your assistance.
Unfortunately the telemetry module to the GCS was not connected as the wing is so small and weight is everything. I have done my best to download a particular flight where the problem occurred in Auto and RTL mode - I had to switch to manual mode to save the wing. The procedure to download via Mavlink and then attempt to convert the file is really complicated (in my humble opinion), but I have done my best. I have no idea how to read the data I have downloaded as it doesn’t “Playback” as is the case with a normal telemetry stream.
I have tried numerous times to upload either a .bin file, which just gets stuck on the upload process, or a log.gpx file which is not accepted for upload by your website…
The current parameters from the config/tuning page on Mission Planner, following flying the wing in AutoTune mode are as attached in the jpeg below.
I appreciate your help![/quote]
Hi,
Can I suggest if you are having issues uploading the .bin file you can use drop box or something similar to upload it to and then share it out publicly and put the link in a reply post. Without the .bin file it’s going to be really hard to help. Don’t worry about the .log or the .gpx file, that data can be obtained from the .bin file.
On the downloading of the log files, I found the interface isn’t the best but it is functional. I’m just a user like you, so it’s not my website 
Chris
Hi Chris, I’m new to DropBox but have managed to upload the Bin file there - this is the link:
dropbox.com/s/puxvmyiolcs6y … 7.bin?dl=0
Hope the data helps!
Many thanks
jonathan
[quote=“Jono2014”]Hi Chris, I’m new to DropBox but have managed to upload the Bin file there - this is the link:
dropbox.com/s/puxvmyiolcs6y … 7.bin?dl=0
Hope the data helps!
Many thanks
jonathan[/quote]
Hi,
I’ll have a quick look tonight, but others might beat me to it.
Chris
Hi,
I just wrote a long response and lost it all… So I’ll do the abridged version. Let me know if you need clarification on items and I’ll do the long version for the selected bits.
I noticed that your ARSPD_FBW_MIN is 8, yet the ‘stalls’ seems to occur at 13m/s from the logs. I’d recommend confirming your stall speed and set the MIN value to slightly higher.
It seems that TRIM_ARSPD_CM is set to 15m/s (1500), if the stall speed is at 13m/s then this is way to close. I’d increase it.
Your min airspeed was 12.5m/s when airbourne. I noticed you were lucky not to crash on one recovery (just 5m to spare). It seems that it might be loosing alt (according to the baro readings) and this might be linked to the lower airspeed (as it also seems to pitch up alot - 20 degrees).
Also it seems that throttle is only at 30% as I think it’s struggling to get down to 15m/s, odd as I would have thought that with the pitch up it and drop down to 15m/s that it would throttle up if it dropped much more. It makes me think that the stall speed is around 13 m/s.
The above advice you’ll need to assess if its suitable for your needs.
Regards,
Chris
Hi Chris, many thanks for taking the time to respond - I will review the parameters you suggest and see if it makes any difference.
Appreciate your help…and YES…the one stall was really close to a full blown crash 
[quote=“Jono2014”]Hi Chris, many thanks for taking the time to respond - I will review the parameters you suggest and see if it makes any difference.
Appreciate your help…and YES…the one stall was really close to a full blown crash [/quote]
No problems, if it was flat ground that was much closer than I’d have liked - nice work, let us know how it goes once you’ve had some time to try the different parameters.
Hi Chris, sad news - The plane flew ok for 1 flight and then spiraled to the ground under power for no apparent reason. The controls didn’t work at all, although I could see in the telemetry that modes appeared to change as I tried to save the plane. the plane was a complete write-off. Your suggestions to the parameters had worked perfectly and the plane was flying autonomously really well. I upgraded to Plane 3.5.2 - perhaps this had something to do with it?
I have attached the telemetry and log files at the dropbox links below:
Any help would be greatly appreciated!
Hi Jono,
That’s not good mate, sad to hear thats what happened. Good to hear that you at least got one good autonomous flight out it.
3.5.2 shouldn’t cause it to crash, its a stable build from what I can see. I’ll have a look at those logs the next couple of days, it would be good to know why it happened.
Chris
Hi Chris, I may have uploaded the wrong log file - I think this is the right one:
Here is a prior flight the day before:
many thanks!