Alt hold modes too "pulsey" - adjust via EKF or Alt hold P? - Discussions

Hi all,

Running an "endurance" quad on U7 420kv, 1855", 8S, AUW 5.7kg. Insert comments about using "power" Motors on an "endurance" rig here: ;-)

Using 3.3 on Pixfalcon (mini pixhawk) with good results. Tune level is good. However, I am getting a pulsing/nervous alt hold.

In the past on previous endurance rigs which suffered from floatiness, I would sacrifice accuracy for stability, and reduce Alt Hold P rate. But should I do this now? Would I be better tuning the alt hold through EKF - specifically EKF_ALT_NOISE? I'm assuming it's still the P rate, as the Barometer is in a case, and inside the vehicle away from prop wash so the pulsing must be coming from the tune, rather than baro fluctuations.

Replies

Mark Anthony December 14, 2025 at 7:43pm

Gotta figure out whether the pulsing is coming from measurement noise or controller gain for sure. Do a hold and see if baro altitude is noisy, even in the case. If baro is smooth but throttle hunts, it’s more likely controller gains. Also maybe upgrade from 3.3... better filtering and you won't have to use vertical P so much.

I'm interested in maximizing endurance right now. What kind of flight time are you getting? What's the exact battery?

This reply was deleted.