Mapping with two Drones

[cluma]

Hi !

I have following task: I should map as quickly as possible an unknown environment with two Drones. Each one should navigate autonomously.

Now I wonder what makes more sense, have rtabmap running for each robot and try to fuse both robot maps or aggregate each of the pointclouds and create one single map with the fused pointCloud ?  

What would you suggest is more efficient ? Do you have any recommendations ?

Greetings
Christian

[matlabbe]

Hi,

They could run independently a rtabmap node. To merge the maps, ideally you would need to make sure the two drones are starting from the same location (looking at the same thing so that in next step a loop closure can be detected on start) and their trajectory may overlap (with very similar point of view) in some areas to further find more loop closures afterwards (this will help to align better the two maps together). Once the maps are created, you can merge (with assumption that loop closures can be detected between the maps) the map with:

rtabmap-reprocess -a "rtabmap_drone1.db;rtabmap_drone2.db" output_combined_map.db
rtabmap-export output_combined_map.db

Other option is just to export the point cloud from each map independently, and manually align them in CloudCompare. This approach could be fine if there are no overlaps between the map, but if there are overlaps, there could be some deformations/drift that make it difficult or impossible to align perfectly.

cheers,
Mathieu