Vehicle doesn't preserve its height in offboard mode

AlexKlimaj · January 7, 2025, 9:50pm

[Bug] Unstable height estimates

opened 07:26AM - 30 Nov 24 UTC

bug-report

### Describe the bug We are using an ARK Pi6xFlow without GPS and are trying …to reliable takeoff to 2 meters. We use both EKF2_BARO_CTRL as EKF2_RNG_CTRL and the HGT_REF is set to barometric. When taking off, sometimes it goes to 2m, but most of the time to somewhere between 3 and 5. Using 1.16.0 alpha, the height was around 1m ### To Reproduce 1. Drone switched on 2. Armed 3. Takeoff to 2m command issued 4. Measure physical distance as soon as the height seem stable) ### Expected behavior Go to the correct height (more or less since exact would be impossible off course) ### Screenshot / Media _No response_ ### Flight Log barometric hgt ref (result 3.2m): https://review.px4.io/plot_app?log=514ae575-9d2e-4687-ab55-6e8836979b02 Range hgt ref (result 2m) https://review.px4.io/plot_app?log=b3753550-44ac-439a-905b-933f7a3932c3 Using 1.16.0 alpha : https://review.px4.io/plot_app?log=8122ff4b-e309-41f5-9257-55d74abbdb5d ### Software Version release 1.15.0 stable One test with 1.16.0 alpha ### Flight controller ARK Pi6xFlow board (Dexi Airframe from DroneBlocks) ### Vehicle type Multicopter ### How are the different components wired up (including port information) ARK board to ESC to Motors. Pi CM4 on ark-board, using MicroUXCREAgent to transform UORB to ROS2 topics. RC and a LED ring are connected to the ARK board as well ### Additional context After takeoff, the height should remain stable, regardless of what the terrain is doing. That's why we want to use barometric height reference, since a distance sensor will cause problems. We're also adding VIO using markers, but don't believe that this would be more reliable then a barometer

@Patrik_Pordi1 is working on this right now with @bresch

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Vehicle doesn't preserve its height in offboard mode

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