Obstacle Detection Nodelet & /local_grid_obstacle

[abcamiletto]

Hi Mathieu, it's my first post here

I'm using rtabmap_ros to do navigation on known and unknown envs, and i thought i had to use the Obstacle Detection nodelet and feed the (local) costmap2d plugin with its output (/ground and /obstacles).
While doing so, i found that rtabmap publish two interesting topics:

/rtabmap/local_grid_obstacle
/rtabmap/local_grid_ground

To me, it seems like it's exactly what i need but i couldn't find any reference to these topics in the doc.
What are the differences between these topics and the ones published by the obstacle detection nodelet?
Are there any params i can tune to adjust these 2 topics to my needs? I'd like it to run at more than 1Hz, but maybe that's bounded by my XavierNX

Thank you in advance!

Andrea

[matlabbe]

Hi,

It looks like that topics have been added in this commit: https://github.com/introlab/rtabmap_ros/commit/b6701866108a263c9117f98b112ba20f7d724012

I think it was for debugging purpose, it is why there is no documentation. Those topics give the same output as obstacles_detection nodelet for the last node added to the map. They are published at 1 Hz because by default rtabmap updates at 1 hz (Rtabmap/DetectionRate=1). If you need faster framerate, it would be better to use obstacles_detection nodelet instead. There is an example here where you could feed your depth image and camera_info instead (or directly a point cloud).

To adjust the parameters (both for rtabmap and obstacles_detection nodes), see:

$ rtabmap --params | grep Grid/

cheers,
Mathieu