Zed 2 camera stereo mapping with laser

[jseng]

Hi,
  I using RTABMAP with a Zed 2 and a 2-D laser scanner.  I am able to make a map in RGB-D mode using the laser scanner to make the 2-d occupancy grid.  Now, I am trying to use the Zed2 in stereo mapping with the laser scanner.

  I am getting the following warnings:

  [ERROR] (2020-07-08 16:50:30.982) RegistrationIcp.cpp:1301::computeTransformationImpl() Laser scans empty?!? (new[76]=0 old[55]=0)
[ WARN] (2020-07-08 16:50:30.983) Rtabmap.cpp:2567::process() Rejected loop closure 55 -> 76: Laser scans empty?!? (new[76]=0 old[55]=0)

  It says the laser scans are empty, but I am using the same topic that worked in RGB-D mode.  The map is built correctly if I use stereo depth to make the occupancy grid.  Any help is appreciated.  Thanks.

[matlabbe]

Hi,

You cannot synchronize stereo images with lidar. Make sure you use stereo_sync nodelet to pre-sync left/right images and camera info, then use subscribe_rgbd=true. The rgbd_image output from stereo_sync will be connected to rgbd_image input of rtabmap. rtabmap will recognize that the format used in rgbd_image is stereo images.

Note also that is recomended to use rgbd_sync nodelet with RGB-D data as well if you synchronize a lidar.

cheers,
Mathieu

[jseng]

Got it.  Thanks!