Flight instability

[SimpleMathmatics]

Dear Hoenig,

First of all, thank you for this awesome project! It is a lot of fun to work with.

To our issue:
We are experienceing flight instabilities when flying our crazyflies with crazyswarm. Specificially, some cfs start flying in circles and eventually crash, as it can be seen here.

To our setup:

• We use a vicon vero motion capture system
• The cf version is 2.1
• We use single marker tracking
• All radios and cfs have the latest firmware installed

It would be highly appreciated if you could share your first thought, since we couldn't find out, what could be the issue here.

Thank you very much! greetings from Austria,
All the best,
Julian

[whoenig]

Thanks for the detailed report! I think your problem is bitcraze/crazyflie-firmware#870. If you apply the fix described there, re-compile, and re-flash the STM32 firmware it should work fine.

[whoenig]

I assume this is still set to False?

crazyswarm/ros_ws/src/crazyswarm/launch/hover_swarm.launch

Line 36 in 424d074

send_position_only: False # set to False to send position+orientation; set to True to send position only

[SimpleMathmatics]

yes, it is still set to False!

[whoenig]

Does the rviz visualization show the wrong yaw angle as well? If so, it's another EKF problem I think. Otherwise it might be a tracking problem.

[SimpleMathmatics]

Thanks for the suggestion...I will verify it on the beginning of next week!

[SimpleMathmatics]

rviz incorrectly showed perfect aligned yaw angles. As mentioned below, setting send_position_only to True solves the issue for us. Thanks

[whoenig]

As an update: I had the same problem last week when using the single-marker tracking. For me, the issue was resolved when changing send_position_only to True. There seems to be currently no safeguard in the code that prevents the misuse (using single-marker-tracking + setting this option to false results in sending garbage orientation information). This was with the latest master firmware from Bitcraze.

I created a new issue at #580 to automatically check this combination and either prevent it or throw an error.

[SimpleMathmatics]

Hello @whoenig ,

As you suggested, setting send_position_only to True indeed results in a stable flight behaviour. Thank you very much!
All the best,
Julian