I am in the process of setting up a wing. Manual and Acro (with adjusted roll/pitch rates) works well. A Autotune also worked fine and about doubled the PID’s from the very conservative initial setting.
I hope you can answer some of my questions, mainly to helo me better understand.
There is a parameter ACRO_LOCKING. My understanding is if enabled it will hold the attitude and will not level. What does it do if not enabled? Level?
Is there a mode that is acting like acro but limits bank and pitch angle? I know there is FBWx but these seem to be self leveling modes
If I switch to Loiter (same with Circle) on the bench the servos seems to behave erratic. I’d expect servo movement to one position as the system tries to change attitude (turn or so) and remain there as the plane is not reacting with a change in attitude on the bench. Instead the servos seem to randomly change throw and direction. Correct?
I noticed I have low pitch authorithy in Autotune which I guess is using FBWA. Is this due to the low pitch angle defaults (+20, -25)? What are reasonable values for pitch and roll limits?
FYI: I am a bit of a beginner myself (with about two months experience with ArduPlane).
- no help
- FBWB is self-leveling. But FBWA is NOT self-leveling. I like TRAINING mode, as the plane responds just like an RC plane but won’t allow it to roll or pitch past the limits.
- I would not worry about this too much. my experience is that is is hard to do much bench testing with auto-pilots. My servos also do weird things on the bench.
- Autotune starts out with very little servo authority ( at least on my Sig Kadet Senior). When I first flew in autotune mode, I could barely execute a turn in one direction and had to turn the other way. Eventually (after many minutes - at least five minutes I think), the plane begins to respond more. In my case, the autotune changed the PID parameters by quite a bit. As I recall, it doubled the “P” parameter for pitch and roll. I set my roll limit at 45 degrees and pitch limits at 25 or 30 degrees.
I’d recommend following the instructions in the autotune guide before altering your pitch and roll angles, as long as you are able to maintain control with the heavily dampened PID values initially. Altering the pitch and roll angles to increase control in autotune mode can end up giving the false impression of a tuned airframe.
I did the same thing as you on the first fixed wing I set up. It flies fine, but there are small details that I couldn’t figure out until my 2nd build, such as trying to dial in the xtrack error.
As for the ACRO parameter, I am guessing at this and not speaking from experience, as all of mine are set up for auto flight for surveys. I’m guessing that parameter is intended to be used with a flight mode switch to acro mode, and not manually changed. I won’t quote the acro mode text as it sounds like you’ve read through the flight modes, but I did want to add one tidbit from personal experience.
-Make sure to pay attention to the way altitude and throttle works in FBW-B mode, especially if you have a geofence enabled. I might have heard a story about a friend (definitely not me) that crashed my…er, his plane into a tree while trying to land in FBW-B mode due to inexperience.