We have a Starling 2 that normally flies at approximately 1000-1300 m above sea level. It starts struggling around 1800 m, and at approximately 2400 m above sea level, it only climbs about 20 cm. Even in manual/PostCtrl mode, it does not climb.
Observations:
Battery charge: 7.3-8 V.
Rotor speed: 12,000 RPM.
Takeoff is detected, but the drone cannot climb.
Geofence and altitude parameter limits were checked (no strict limits were found).
The drone's position is estimated using VIO (OpenVins). GPS is disabled, and a barometer is not used to aid in altitude estimation.
Hypothesis:
At high altitude (2400 m), air density reduces thrust; the hover throttle is likely saturated. We increased MPC_THR_MAX and adjusted MPC_THR_HOVER, pending testing.
Request: Are any adjustments to the PX4 (acceleration/hover/air density) or propeller/motor modifications recommended so that the Starling 2 can maintain flight at approximately 2600 m above sea level?
Attachment: PX4 Flight log from 2400 meters above sea level.
https://review.px4.io/plot_app?log=45254900-3c62-4bc8-bcb3-6cf669b0e9e2
