Collision Avoidance for multiple UAVs when not using world_origin frame for odometry

[migsdigs]

Hi there,

I was hoping you could please answer some questions related to collision avoidance of multiple UAVs that are not using GPS for navigation. Is the Inter-UAV Collision Avoidance designed to work in the case that the UAVs are not utilizing GPS?

For context, I have 2 UAVs in simulation using lidar-inertial odometry. I have created a common origin frame based on a static offset at takeoff, so the drones are capable of knowing each others location in their own respective local frames (subject to drift of course).

I have the collision avoidance enabled in the custom_config and I can see on the topic /control_manager/mpc_tracker/diagnostics that it is enabled (and sees other active UAVs), but it is not avoiding collision at any point.

Your feedback would be greatly appreciated.

Kind regards,
Miguel

[migsdigs]

Looking into the source code it appears as though collision avoidance will only be triggered if either GPS or RTK are used as state estimators. In this case, do you recommend changing the source code to include other methods of state estimation, or can you recommend any other solution?

Thank again

[klaxalk]

Hey, the mutual collision avoidance only works under GNSS, since that provides the UAV with a common frame of reference. With most other localization systems that we use there is not way to ensure the frame of reference would be the same, thus the collision detection would be impossible.