is it possible to use RTABMAP without RGBD image?

[dholukeval]

I do not have RGB-D camera (or stereo cameras). I do have monocular RGB camera and 3D long range LiDAR. I have similar sensor setup in Gazebo as well.

Is it possible to use RTABMAP for such scenarios? or is it is must to have RGBD information?

Furthermore, I do not have wheel odometry as I am working on autonomous boat application. I am generating odometry information from GPS using navsat_transform_node package. This seems to work well. (I am testing it on Gazebo)

I also tried using icp_odometry to generate LiDAR odometry but it shows me null values. DO I still need LiDAR odometry for rtabmap. I use rtabmap_slam for generating map. but on rviz it suggest that "NO map recieved".

Am I doing something wrong?

[matlabbe]

For the basics, you can feed mono camera image + 3D lidar + odometry from navsat_transform_node to rtabmap node. You don't need ICP odometry. However, I have doubt that only using navsat_transform_node for odometry would give accurate results in real world. Well, you may give a try if you have already the setup ready.

Is the boat cruising close to the shore or on a river in the middle of the city? In the middle of ocean, I have doubt that lidar would be of any help (same for the camera).

If you feed only monocular image to rtabmap, it won't be able to close the loops (depth is required for that). rtabmap has an option gen_depth to generate depth for the camera from the lidar, like in this example, that would make rtabmap able to close loop closures in your scenario.

cheers, Mathieu