Handheld map for later usage on the robot

[mtal]

Dear Dr. Labbé, I am posting again since my thread moved down. I have the following RTAB-Map setup on my robot: 2x D435 (one is placed lower and one on top of the robot, 90° rotated and there is a TF between these two) and 1x 2D LiDAR LDS-01 (was included on TB3). I am using wheel odometry coming from OpenCR board. Here is my launch file:

<launch>

   <group ns="d435_bottom">
    <node pkg="nodelet" type="nodelet" name="nodelet_manager1" args="manager"/>
    <node pkg="nodelet" type="nodelet" name="rgbd_sync1" args="load rtabmap_ros/rgbd_sync nodelet_manager1">
      <remap from="rgb/image"       to="color/image_raw"/>
      <remap from="depth/image"     to="aligned_depth_to_color/image_raw"/>
      <remap from="rgb/camera_info" to="color/camera_info"/>
      <param name="approx"          value="false"/>
    </node>
   </group>
   
   <group ns="d435_top">
    <node pkg="nodelet" type="nodelet" name="nodelet_manager2" args="manager"/>
    <node pkg="nodelet" type="nodelet" name="rgbd_sync2" args="load rtabmap_ros/rgbd_sync nodelet_manager2">
      <remap from="rgb/image"       to="color/image_raw"/>
      <remap from="depth/image"     to="aligned_depth_to_color/image_raw"/>
      <remap from="rgb/camera_info" to="color/camera_info"/>
      <param name="approx"          value="false"/>
    </node>
   </group>

  <group ns="rtabmap">

    <!-- Visual SLAM (robot side) -->
    <!-- args: "delete_db_on_start" and "udebug" -->
    <node name="rtabmap" pkg="rtabmap_ros" type="rtabmap" output="screen" args="--delete_db_on_start">
      <param name="subscribe_depth"  type="bool"   value="false"/>
      <param name="subscribe_rgbd"   type="bool"   value="true"/>
      <param name="subscribe_scan" type="bool" value="true"/>
      <param name="rgbd_cameras"     type="int"    value="2"/>
      <param name="frame_id"         type="string" value="base_footprint"/>
      <!-- <param name="gen_scan"         type="bool"   value="true"/> -->
      <param name="map_negative_poses_ignored" type="bool"   value="false"/>        <!-- refresh grid map even if we are not moving-->
      <param name="map_negative_scan_empty_ray_tracing" type="bool" value="false"/> <!-- don't fill empty space between the generated scans-->

      <remap from="odom"          to="/odom"/>
      <remap from="rgbd_image0"   to="/d435_bottom/rgbd_image"/>
      <remap from="rgbd_image1"   to="/d435_top/rgbd_image"/>
      <remap from="scan"          to="/scan_filtered"/>

      <param name="RGBD/NeighborLinkRefining" type="string" value="true"/>
      <param name="RGBD/ProximityBySpace" type="string" value="true"/>
      <param name="RGBD/AngularUpdate" type="string" value="0.01"/>
      <param name="RGBD/LinearUpdate" type="string" value="0.01"/>
      <param name="RGBD/OptimizeFromGraphEnd" type="string" value="false"/>
      <param name="Grid/FromDepth" type="string" value="false"/>
      <param name="Grid/CellSize" type="string" value="0.02"/>
      <param name="Vis/EstimationType" type="string" value="0"/> <!-- should be 0 for multi-cameras -->

      <param name="Reg/Force3DoF" type="string" value="true"/>
      <param name="Reg/Strategy" type="string" value="1"/>

      <param name="Icp/VoxelSize" type="string" value="0.05"/>
      <param name="Icp/MaxCorrespondenceDistance" type="string" value="0.1"/>
    </node>

  </group>

</launch>

I had this idea to use one D435 on my laptop and generate a map using RGBD visual odometry in handheld mode and later on to transfer the generated rtabmap.db file to the previous mentioned setup. I was using the following commands from RGB-D Handheld Mapping:

roslaunch realsense2_camera rs_camera.launch align_depth:=true

roslaunch rtabmap_ros rtabmap.launch \
    rtabmap_args:="--delete_db_on_start" \
    depth_topic:=/camera/aligned_depth_to_color/image_raw \
    rgb_topic:=/camera/color/image_raw \
    camera_info_topic:=/camera/color/camera_info \
    approx_sync:=false

I tried it already but when I click on Download button it ignores the previously saved map. In case you ask, I removed --delete_db_on_start when I try to load the previously saved map. I wanted to ask should it work like this? If this concept would work I would move to the iOS RTAB-Map and try the same with an iPad. Thanks in advance. Thanks in advance. Cheers, Mujo

[matlabbe]

It could, but the problem is that the robot may never localize on the map created with hand-held mapping because the point of view of the camera would not be similar.

If you restart the robot in localization mode (Mem/IncrementalMemory=false) and without --delete_db_on_start, you should be able to see the map with Download button, unless there is a problem with ROS_IP between the computers.

If you restart in mapping mode (even without --delete_db_on_start), rtabmap creates a new session in the database, and you won't be able to see the previous session until the robot localizes in it.

[mtal]

Thank you for your answer.

I am using it locally on the same computer - the .db file I generated in hand-held mode is transferred to my the robot computer and the node starts on it. It's the only device in my ROS network.

I have posted some videos here as well:

https://github.com/introlab/rtabmap_ros/issues/602#issuecomment-886518243

Sorry for double posting on Github I wasn't sure where I can get the answer faster.

Cheers.