Multi-Robots Mapping and Localization - RTAB-MAP

[Leo]

Multi-Robots Mapping and Localization - RTAB-MAP

Dear Labble

I wonder if the RTAB-MAP has the ability to work in a multi-robot scenario or multi cameras (Kinects), where both would be mapping the same environment and of course creating a single map?

Thank you for your attention.

[matlabbe]

Hi,

No, multi-robots mapping the same map online is not supported. You may have multiple RTAB-Map running at the same time, but they won't find loop closures between them online. However offline, it could be done by processing back each created database one after the other in one RTAB-Map (like having multi-sessions of the same robot), then loop closures could be found between the maps if the robots visited the same areas.

RTAB-Map doesn't support multiple cameras on the same robot (unless with this hack for 2 kinects).

Cheers,
Mathieu

[Leo]

Thanks again, so I can put some robots running different Rtabmaps simultaneously and then join both databases on a map but even if offline? Use the standlone version.

[matlabbe]

Each robot can run RTAB-Map on its own. When the robots have finished mapping, a database is created on each robot. Copy all these databases on a single computer. Open the standalone version, set the parameters you used in ROS, create a new database, then select "Detection->Select source->Database..." and process the first database. When it is finished, you can select the second database and so on.

See this tutorial for an example of merging multiple sessions.  

[Leo]

Mr. Labbe follow the tutorial and tips that suggested first made me for a particular environmental area map saved the base, then made the second map revisiting one particular area of the first map made and saved the same way the base, then the create a new database and choose the parde the Select source> Database ... and choose my base number 1, I can see being recovered all my map correctly and to complete the process repeated choosing the base 2 but by the end only see second map done and not both !!! Still saved the base and went to open the Database viewer and I see that there are points for the first map saved but if you click to see the global map only shows me the second map !!
If possible I would like to help me when I doing wrong or if it was just some other menu so I can view both maps together.
thank you

[matlabbe]

Hi,

While processing the second database, there should be a loop closure found with the first session to actually merge the two maps. It seems that no loop closures were found between the two maps, so only the latest map is shown in rtabmap, but the first map is still saved in the database.

In the database viewer, you can get the first map by changing "Optimize from" under the "Graph view" panel. By default, it generates a map from the latest node added, so only the second map is shown if there were no loop closures with the first map. If you set "Optimize from" to a node ID of the first map, it will generate only the first map. In the Edit menu, the "View 3D map..." shows the map referred by "Optimize From". To know which node are in which map, you can look the number between "[ ]" next to the Index/Id of the node shown with the two main sliders.

Cheers

[Leo]

Thanks for the great help,
I will redo trying to resist an area of longer and the best way for you to recognize binding sites I searched take another wall in common and included objects it still had the problem I mentioned in the previous text will try to redo !! and I will return with resultador
Thanks Again!

[jacksonkr]

Getting multiple maps in the same frame online is monumental to the scalability of rtabmap.

How can I help with this? Is there a plan in place for building out this feature? If yes then I'll start a branch on it. If not, can we discuss / create a basic outline of what the development for this will look like? I'm happy to start on the development for this.

[matlabbe]

Yes, this discussion could be done under another topic. Generating a global map with multiple robots online requires quite a lot of developments (e..g, creating a global map server and a robust low-bandwidth robot<-->server communication), though not entirely incompatible with the current rtabmap framework (which targets more multi-session mapping with a single robot, no wireless issues!).

cheers

[RockyFath]

Hi everyone...i am a new user here. As per my knowledge multi-robots mapping the same map online is not supported. You may have multiple RTAB-Map running at the same time, but they won't find loop closures between them online. However offline, it could be done by processing back each created database one after the other in one RTAB-Map, then loop closures could be found between the maps if the robots visited the same areas.

pcb+assembly+services

[Jam]

Hi all,
Is there any updates about this topic? (branch or discussion)
I am really interesting in multi-robot slam on RTAB-Map.
Thanks!