rtabmap stops mapping when scanning a certain area

[Mackhu]

Hi Mathieu

I do the 3D mapping by using RTABMAP and Realsense L515. It works well at the beginning. However, when I move to camera to scan some certain areas, it freezes and stops mapping.

There are errors in the terminal:
[pcl::IterativeClosestPoint::computeTransformation] Not enough correspondences found. Relax your threshold parameters.
[ WARN] (2022-02-18 12:46:55.808) OdometryF2M.cpp:529::computeTransform() Registration failed: "Cannot compute transform (converged=false var=1.000000)" (guess=xyz=0.000000,0.000000,0.000000 rpy=-0.304493,0.475385,2.567989)
[ INFO] [1645159615.809399641]: Odom: ratio=0.000000, std dev=0.000000m|0.000000rad, update time=0.062001s
 
what may cause this issue?


Thanks

[Mackhu]

Another issue is that when I scan the same area for the second time, it doesn't match to the previous frame. And it is constructed once again. what can I do to address this issue?

Thanks

[matlabbe]

Hi,

are you using a config similar to this example: http://official-rtab-map-forum.206.s1.nabble.com/Kinect-For-Azure-L515-ICP-lighting-invariant-mapping-tp7187p7899.html ?

Be sure to always have 3 planes (x,y,z) in camera field of view, otherwise ICP will get lost easily. We assume an environment with a lot of geometry constraints (a flat wall is not!).

Until a loop closure is detected, the two maps won't be aligned.

cheers,
Mathieu

[Mackhu]

Thanks Mathieu

Now I use rgbd_odometry, which makes the mapping more smooth.

I have another question.

what formats can the point cloud created by rtabmap be converted into?

[matlabbe]

Hi,

point clouds can be exported in PLY and PCD. If rtabmap is built with PDAL library, it could export in any format pdal is built with (like LAS).

cheers,
Mathieu