I'm trying to get an octocopter I built to perform well enough on Loiter. Stabilize always works really well, but loiter sometimes works and sometimes doesn't.
It shows toilet bowl-like behaviour, where it spirals out of control. Horizontal speed keeps increasing until it touches ground or hits something.
I tried the following, to no avail:
- Calibrated compass using On-Board calibration. Offsets: (X:~16 Y:~49 Z:~35)
- Recalibrated acc and gyros
- Adjusted (without adjusting other params) (+50%) POS_XY_P
- Adjusted (without adjusting other params) (+100%) WPNAV_LOIT_MAXA
- Tried flying with auto declination enabled
- Tried with manual declination
- Double checked declination
- Compass-motor calibration done (~30% interference at home, tied down).
- Moved flight controller upwards, away from electronics
I use a PX4 (actually a Pixhack, which is almost identical but with better EMF shielding) with Arducopter 3.5.2.
Sometimes it works, then the next day it doesn't work at all.
Log file attached. Screenshot plotting PosX vs DPosX and VelX vs DVelX attached as well.
Feel free to blurt out whatever comes to mind. I am utterly desperate. There must be something I am completely missing!