Trouble setting up rtabmap on ROS with bag file

[chris.ferra]

Hi everyone,
I'm currently having trouble setting up rtabmap on ROS with a bag file that I have. I'm running ROS noetic on Ubuntu 20.04, and I've been trying to get the rtabmap node to work with this bag file.
I've tested with the bag provided in this tutorial and it works perfectly.

My problem is that when I run the rtabmap node on this bag file, I can't see any data being published from the node. The console doesn't really show any error or warning messages, so I'm not sure what's going on. As a result I can't see any map on rviz.

Info on the bag:


My launch file:
rtab.launch

Rviz view:



I'm hoping that someone here can help me figure out what's going on and how to resolve this issue cause I've been stuck for serveral days...
Best regards

[matlabbe]

Hi Chris,

Thx for sharing the data.

When using the bag, you may want to decompress before playing it to avoid lags ("rosbag decompress ..."). Otherwise, rtabmap was complaining about missing TF, in particular base_footprint and /stereo/left frames. I added them manually like this based on existing frames:

  <node pkg="tf" type="static_transform_publisher" name="base_footprint_to_base_link" args="0 0 0 0 0 0 base_footprint base_link 100"/>
  <node pkg="tf" type="static_transform_publisher" name="left_to_stereo_left" args="0 0 0 0 0 0 left /stereo/left 100"/>

Ideally, you have to fix your URDF file.

I also see that you have an IMU, you can compute the quaternion and feed it to stereo_odometry and rtabmap nodes like this:

  <node pkg="imu_filter_madgwick" type="imu_filter_node" name="imu_filter_node">
      <remap from="imu/data_raw" to="/imu"/>
      <param name="publish_tf" value="false"/>
      <param name="use_mag" value="false"/>
   </node>

  <node pkg="rtabmap_odom" type="stereo_odometry" name="stereo_odometry" output="screen">
    [...]
    <param name="wait_for_transform" type="bool" value="true"/>
    <remap from="imu" to="/imu/data"/>
  </node>

  <node name="rtabmap" pkg="rtabmap_slam" type="rtabmap" output="screen" args="--delete_db_on_start">
    [...]
    <remap from="imu" to="/imu/data"/>
    <remap from="gps/fix" to="/gps/fix"/>
  </node>

Note that I also took the liberty to feed GPS topic to rtabmap too, so that we can export the poses in KML format with rtabmap-databaseViewer and also compare trajectory (blue) with GPS (green):




Regards,
Mathieu

[chris.ferra]

Thank you so much, you saved me