I have followed the instructions at 6.1 here:

• http://wiki.ros.org/rtabmap_ros/Tutorials/MappingAndNavigationOnTurtlebot

and when executing roslaunch rtabmap_ros demo_turtlebot3_navigation.launch I can't get mapping working as no map frame exists and relatedly no transform from base_footprint to map. The error messages I get are:

Timed out waiting for transform from base_footprint to map to become available before running costmap, tf error: canTransform: target_frame map does not exist.

The /map topic is listed but it isn't publishing messages.

I also get warnings about /rgbd_sync, /odom and /scan not publishing (/odom and /scan are on the topic list but not /rgbd_sync).

I have looked at the suggestions in section 7 on known issues:

There are no leading / in the frame names in the listed YAML files.

In turtlebot3_remote.launch the state_publisher rate is set to 50Hz already.

There is no wait_for_transform argument in the demo_turtlebot3_navigation.launch file, adding it in does nothing.

I am running ROS melodic on Ubuntu 18.04. I've changed nothing (other than the suggested fixes which didn't work so I reverted the changes), I just downloaded the packages and tried running the specified launch files.

I really need the demo running so I can understand how things work and build upon it.