So I am flying my vario helicopter in stabilize mode great. I am venturing into AltHold and am seeing some strange behavior.
I noticed that my BarAlt and Alt were not matching up. So I reduced the INAV_TC_Z value which helped a lot.
So then today I am flying and I flip to AltHold and it actually is working ok... So I flip back to Stab, move the heli around a bit then flip back to Alt Hold and it immediately gives full negative and goes for the dirt! Here you can see the Alt/BarAlt and throttle out graphs...
What am I missing? Why is this happening?
Also, here is my vibration graph...
Any advise is much appreciated!
Replies
have you tried changing the mix between baro and gps 3d fix?
The new vibration plate is working well. After going back and forth between the PIDs and INAV_TC_Z values a bit, I found its sweet spot. I was able to do a few successful AltHold flights and it is very smooth, even down to a landing.
I fabricated an anti-vibration mount that is now closer to the rotor mast (CG). This dropped my Z axis vibrations quite a bit which enabled me to do 4 successful AltHold flights. The heli is still bobbing up and down a bit, I assume PID tuning will fix this?
Chris it seems that something happened during stabilize, look at the increased range (just before switching Alt-Hold the second time). Did you see anything wrong from outside? engine bolts all properly tightened ? Tail boom braces ? It looks like something came loose suddenly, thus generating all those vibrations (as an example on an Xcell converted to gasser I experienced one broken bolt in the clutch/engine support structure, showing a sudden increase in vibrations) .