rtabmap_ros, map-to-odom, and visual odometry

[Jim Rothrock]

I am using rtabmap_ros with stereo image input. rtabmap_ros is broadcasting the map-to-odom transform, and ekf_localization_node is broadcasting the odom-to-base transform. I've noticed that the map-to-odom transform is always an identity transform. Is the map-to-odom transform modified only when a loop closure is detected? I was hoping that it was using stereo visual features to perform visual odometry between loop closure detection events.

[matlabbe]

Hi,

Yes, map-to-odom is updated only on loop closure. If you need visual odometry, there is a node called rtabmap_ros/stereo_odometry. The odometry output of stereo_odometry can be fused in your ekf_localization_node (make sure to disable publish_tf of stereo_odometry if you do so to avoid both nodes publishing odom-to-base).

cheers,
Mathieu