Parameters to use for RTABMap with ORB SLAM

[rakshith95]

Hello @matlabbe , I've managed to compile OTB SLAM with RTABMap, but running rtabmap --params | grep orb only gives me the parameters for the ORB SLAM itself. Is there a way to ensure orb slam actually runs, and a way to check if it does?

I've attached the launch file I've been running so far. If you could tell me which parameters I'll have to add/change (or where I can find documentation on it), that would be great. Thank You! stereo_rtabmap_inria.launch.txt

[matlabbe]

For rtabmap.launch include, add this

<arg name="args" value="-d --Odom/Strategy 5 --OdomORBSLAM/VocPath ~/ORB_SLAM3/Vocabulary/ORBvoc.txt"/>

-d is to start from fresh database (delete the old one), and adjust the OdomORBSLAM/VocPath to where you extracted ORB_SLAM2 or ORB_SLAM3.

To see if ORB_SLAM is actually used, the odometry view in rtabmapviz will look different.

[rakshith95]

Thank you @matlabbe! From the log, I can see that the orb vocabulary is now being loaded at least, so I guess it is running ORB SLAM. I am running it on a docker in a robot, and I did not compile with rtabmapviz. I have a couple of follow up questions:

1. In #707 you mention the following:

   We use it like a blackbox (the front-end), which outputs the pose of the current frame that is fed to RTAB-Map's graph management (back-end).

Is this output pose exposed anywhere, in the form of a topic or sent to TF?

2. Is ORB SLAM used in both the mapping, and the localization modes? In the mapping mode, without ORB SLAM, there is a tf update (and pose topic output) only when loop closures are found; does this mean that if run with ORB SLAM, the frequency of tf and the pose updates will be much higher?

Thank you!

[rakshith95]

To my first question, I see the topics:

/slam/odom
/slam/odom_info
/slam/odom_info_lite
/slam/odom_last_frame
/slam/odom_local_map
/slam/odom_local_scan_map
/slam/odom_rgbd_image

However, the /slam/odom topic just seems to publish Identity zero pose with a very large covariance, and does not update as the camera moves, so I'm not sure what to make of it

EDIT: Forgot to mention that i was using the namespace slam, so all of these would be /rtabmap/.. EDIT 2: Adding example of a /slam/odom message:

header: 
  seq: 2763
  stamp: 
    secs: 1664895558
    nsecs: 824400874
  frame_id: "odom"
child_frame_id: "base_footprint"
pose: 
  pose: 
    position: 
      x: 0.0
      y: 0.0
      z: 0.0
    orientation: 
      x: 0.0
      y: 0.0
      z: 0.0
      w: 0.0
  covariance: [9999.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 9999.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 9999.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 9999.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 9999.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 9999.0]
twist: 
  twist: 
    linear: 
      x: 0.0
      y: 0.0
      z: 0.0
    angular: 
      x: 0.0
      y: 0.0
      z: 0.0
  covariance: [9999.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 9999.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 9999.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 9999.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 9999.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 9999.0]
---

[rakshith95]

Removing the march-native flags while building ORB SLAM2, in all the CMakeLists.txt files (including third_party repos) seems to have fixed it. Not sure if that directly fixed it, or it was something else though.

[matlabbe]

For reference, there are patches to remove -march=native from orbslam2 and orbslam3: https://gist.github.com/matlabbe/f5cb281304a1305b2824a6ce19792e13 https://gist.github.com/matlabbe/c10403c5d44af85cc3585c0e1c601a60

[GVMafeedme]

I am trying to load ORB_SLAM3 with RTAB-Map but it does not seem to make a difference, the odometry tab seems to be the same as before, and matches are not being found:

My launch file has a rtabmap_slam node with these parameters:

<param name="Odom/Strategy" type="int" value="5"/>
<param name="OdomORBSLAM/VocPath" type="string" value="/root/orb_slam/ORB_SLAM3_NOETIC/Vocabulary/ORBvoc.txt"/>

Do I need to add anything else? Are these parameters not correct?

Note: I compiled rtabmap and rtabmap_ros from source with ORB_SLAM3 support

[matlabbe]

@GVMafeedme With rtabmap_viz, set subscribe_odom_info to true to get the statistics in odometry panel.