Hi all,
I am new to APM AP`s and could need your help with a Problem or maybe Understanding the AltHold Mode - also Loiter Mode:
APM 2.6, uBlox external GPS/ Compass, 3.01 Firmware, Quad X.
Flying in Stabelize Mode is without any Problems including a high climb rate. The Quad hovers at exact 50% Thrustway on the RC-Transmitter. After switching to AltHold Mode, the Quad holds the Altitude very well. Also Loiter-Mode works fine for the beginning and without any PID Tuning. But in both Modes, the climbing rate even with full Throttle is low, maybe around 10% - 20% of the possible climb rate compared to the Stabalize Mode. So my Question: Is that "normal"? Hope not :-).
It feels like a strong Rate/ Expo Adjustment on the RC-Transmitter to damp the Stick- Reaction. This behavior is also noticeable for Pitch and Roll but not with this intense. It seems to be a RC-Transmitter Adjustment but I am wondering about why this occurs not in Stabalize Mode. So I think this is not an Issue with the RC-Transmitter, but after hours of reading (sometimes very poor) descriptions of the extensive adjustable Parameters of the APM AP, I wasn`t able to find suitable Parameters for that.
Hope you can help.
Best regards, Tom
Replies
That is indeed expected behaviour for the APM!
The ALT_HOLD and LOITER modes have very large dead bands applied to the RC controller inputs, in order to smooth out the flight. They aren't really designed for doing anything "sporty".
You could try playing with the PID values, which may help a bit. In Mission Planner, look for the Rate Loiter and Altitude Hold PID values. Try upping the "p" value a little bit (by 0.1 at a time) and see if the copter is a little more responsive in the ALT_HOLD and LOITER modes.