What's a good strategy to tune these params?
I'm having trouble getting it to hold target airspeed (it seems to stay below it), and I can also hear it changing the throttle quite a bit, even though it's above target_altitude according to the mission planner (target_altitude in status tab said 272, altitude readout on attitude indicator said 278)
Airspeed got better when I gave it more airspeed->pitch, but I couldn't get energy->throttle to smooth out.
I see that it's based on both airspeed error and altitude error, so I assume it will get better with additional tuning to the airspeed->pitch PID. I'm just worried that it's caused by noise from the sensor.
I know nothing about PID tuning for APM... don't have one yet. But I've got plenty of experience tuning PID for the MultiWiiCopter! In a situation like this where things are pretty different from how a multirotor manages its attitude, I suppose things aren't very equal.
Despite that, I'd move I farther away from 0. In the MWC, I influences how aware the controller is of smallish changes in sensor data, like when the copter is flying in ground effect, descending through its thrust column, or hovering in heavy wind. I gives the controller more context to work with when making a correction decision.
Just guessing out loud!