Take-Off and Land command each fly to xy=[0,0] location instead of on the spot

LaborzaubererTHI

Dear developers,

while connected to PX4 instance over MavSDK, using the python environment, we initiate the take-off and land command.
But instead of the commands being executed on the spot, meaning where the drone is, the drones fly towards its xy=[0,0] location while executing the respectively command. So instead of flying vertical each time, they actually fly diagonal.

More detailed description:
Drone position at [1, 0, 0].
Command takeoff.
Offboard to setpoint [-2,0].
Command land.

April tag #0 is set to “unknown” and no other tag specified.

Result:
Took off and flew diagonal to location: NED = [0, 0, -1.5].
Flew backwards to [-2,0,-1.5] as commanded in offboard mode.
Land command led to a diagonal land flight at [0,0] location, where it initialy took off from.

Expected:
Take-off and land command would lead to vertical flight at the xy-location where it was when initiated.

The flight can be seen here: https://www.youtube.com/watch?v=Trz97csbsz0

Our example is very close to your example offboard_position_ned2.py found here:
https://gitlab.com/voxl-public/voxl-docker-images/voxl-docker-mavsdk-python/-/blob/master/offboard_position_ned2.py?ref_type=heads

From testing PX4 within an gazebo environment, we did not expect such a behavior.

Regards
LabMag

Drone: RB5
System-image: 1.7.1-M0052-14.1a-perf-nightly-20231025
Kernel: #1 SMP PREEMPT Thu Oct 26 05:24:02 UTC 2023 4.19.125
hw version: M0052
voxl-suite: 1.1.2

wilkinsaf

@LaborzaubererTHI

What coordinate frame are you using?

LaborzaubererTHI

@wilkinsaf

We are connected to the drone via MavSDK. We booted the drone at the [0,0] location. Carried it forwards to [1,0] and send the takeoff and land commands via MavSDK.
Due to the fact that I think we are connected to PX4 I suspect we are using its coordinate system.

Regards.

LaborzaubererTHI

@wilkinsaf
@LaborzaubererTHI

How would one go about using the different coordinate systems? All of our code is currently running on an external computer, not on the drone. [Question might need separate thread].

Eric Katzfey

@LaborzaubererTHI Sounds like it may be similar to: https://forum.modalai.com/topic/2533/failsafe-landing-bug-in-px4-1-14/19?_=1713800679314

LaborzaubererTHI

@Eric-Katzfey said in Take-Off and Land command each fly to xy=[0,0] location instead of on the spot:

@LaborzaubererTHI Sounds like it may be similar to: https://forum.modalai.com/topic/2533/failsafe-landing-bug-in-px4-1-14/19?_=1713800679314

Indeed it does.