Drone not reaching altitude set point after takeoff

MAVSDK
1

I’m trying to get my drone to take off and hover at a low altitude - either 0.5m or 1m - and for some reason the drone doesn’t reach the target point as seen in the snapshots from the log.

I am using a really simple MAVSDK-Python script running on an onboard computer that just sets the takeoff altitude to 1m then takes off, sleeps for a few seconds, then lands. For some reason if the altitude is set to 1m the drone doesn’t seem to fly above about 0.5m, and if the alt is set to 0.5m the drone never leaves the ground.

The drone has an RTK_FIXED GPS lock and a tfmini distance sensor pointing straight down reporting the distance correctly - I have no idea why it can’t hit a simple altitude from the takeoff height - does anyone have an idea?

(zoomed in on the fused and barometer separately)

fused
fused970×480 21.1 KB

baro
baro970×480 28 KB

2

I would suggest to first try to print the distance data and check, you can use the telemetry function to print the distance sensor data, by doing this, you can check the current z data of the drone, through which you can see whether your depth estimates are proper or not.