Visual Odometry

[janalberts]

Hi,
I want to use rtabmap on my quadrocopter only for visual odometry.
Can anyone tell me, how to get the odometry information without building a whole map?
Is that even possible?
Thank you so much,
Jan

[matlabbe]

Hi,

Yes it is possible. With RGB-D camera:

<node pkg="rtabmap_ros" type="rgbd_odometry" name="rgbd_odometry" output="screen">
    <remap from="rgb/image"       to="/camera/rgb/image_rect_color"/>
    <remap from="depth/image"     to="/camera/depth_registered/image_raw"/>
    <remap from="rgb/camera_info" to="/camera/rgb/camera_info"/>
      
   <param name="frame_id"     type="string" value="base_link"/>
   <param name="approx_sync"  type="bool"   value="true"/>
</node>

With stereo camera:

<node pkg="rtabmap_ros" type="stereo_odometry" name="stereo_odometry" output="screen">
   <remap from="left/image_rect"        to="/stereo_camera/left/image_rect_color"/>
   <remap from="right/image_rect"       to="/stereo_camera/right/image_rect"/>
   <remap from="left/camera_info"       to="/stereo_camera/left/camera_info"/>
   <remap from="right/camera_info"      to="/stereo_camera/right/camera_info"/>
      
   <param name="frame_id"     type="string" value="base_link"/>
   <param name="approx_sync"  type="bool"   value="false"/>
</node>

See this section for more info.

cheers,
Mathieu

[yu]

Hi, which launch file should i add this in ?

Tks.

[matlabbe]

You can put this in a standalone launch file, or you can put this in the launch file with which you start all the stuff you need.