Implementing an Ouster-based 3D Lidar via rtabmap_ros
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This post was updated on .
I would like to integrate my 3D lidar (an Ouster-16) into rtabmap via ROS similar to how it was done in this post.
However, my current rtabmap launch file (below) does not work as intended:
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Administrator
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Hi,
set subscribe_scan_cloud instead of subscribe_scan for rtabmap node. Also remap scan_cloud instead of scan to point cloud from os1 (same for rtabmapviz): <param name="subscribe_scan_cloud" type="bool" value="true"/> <remap from="scan_cloud" to="/os1_cloud_node/points"/> Based on this tutorial with D435, the rgb and depth images to subscribe would be more like: <remap from="rgb/image" to="/camera/color/image_raw"/> <remap from="depth/image" to="/camera/aligned_depth_to_color/image_raw"/> <remap from="rgb/camera_info" to="/camera/color/camera_info"/> RGBD/LoopClosureReextractFeatures is deprecated, it can be false in recent versions. Set Grid/FromDepth to false if you want the occupancy grid map created from os1 instead of the camera. For 360 3D lidar, set RGBD/ProximityPathMaxNeighbors to 1 to save computation time. Increase Vis/MinInliers >= 15 to reject most bad loop closures. Vis/InlierDistance is not needed as Vis/EstimationType is 1 by default (PnP). As you are using a lidar, there would be some "Icp/*****" parameters to tune. As you are synchronizing a lidar with camera topics, I also suggest to use rtabmap_ros/rgdb_sync nodelet to pre-sync the image topics before rtabmap node (see figure 6 of this paper):
<launch>
<arg name="gui_cfg" default="~/.ros/rtabmap_gui.ini" />
<arg name="launch_prefix" default=""/>
<arg name="output" default="screen"/>
<arg name="rgb_topic" default="/camera/color/image_raw"/>
<arg name="depth_topic" default="/camera/aligned_depth_to_color/image_raw"/>
<arg name="camera_info_topic" default="/camera/color/camera_info"/>
<group ns="rtabmap">
<node pkg="nodelet" type="nodelet" name="rgbd_sync" args="standalone rtabmap_ros/rgbd_sync" output="screen">
<remap from="rgb/image" to="$(arg rgb_topic)"/>
<remap from="depth/image" to="$(arg depth_topic)"/>
<remap from="rgb/camera_info" to="$(arg camera_info_topic)"/>
<remap from="rgbd_image" to="rgbd_image"/> <!-- output -->
<param name="approx_sync" type="bool" value="false"/> <!-- false for realsense -->
</node>
<node name="rtabmap" pkg="rtabmap_ros" type="rtabmap" output="screen" args="--delete_db_on_start">
<param name="frame_id" type="string" value="base_link"/>
<param name="subscribe_depth" type="bool" value="false"/>
<param name="subscribe_rgbd" type="bool" value="true"/>
<param name="subscribe_scan_cloud" type="bool" value="true"/>
<param name="queue_size" type="int" value="10"/>
<param name="scan_cloud_max_points" value="32768"/> <!-- based on os-1 spec: 327,680 pts/second for 10 Hz -->
<remap from="odom" to="/odom"/>
<remap from="scan_cloud" to="/os1_cloud_node/points"/>
<remap from="rgbd_image" to="rgbd_image"/>
<!-- RTAB-Map's parameters -->
<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="Reg/Strategy" type="string" value="1"/> <!-- 1=ICP -->
<param name="Reg/Force3DoF" type="string" value="true"/>
<param name="Vis/MinInliers" type="string" value="15"/>
<param name="Rtabmap/TimeThr" type="string" value="0"/> <!-- set to 0 to disable memory management -->
<param name="Mem/RehearsalSimilarity" type="string" value="0.45"/>
<param name="Grid/CellSize" type="string" value="0.05"/> <!-- 5cm voxel default-->
<param name="Kp/MaxFeatures" type="string" value="400"/>
<param name="Optimizer/Strategy" type="string" value="0"/> <!-- 0 is TORO, Default G20-->
<param name="RGBD/OptimizeMaxError" type="string" value="0"/> <!--When using TORO, seto to 0,otherwise set to 1-->
<param name="Kp/DetectorStrategy" type="string" value="6"/> <!--0=SURF 1=SIFT 2=ORB 3=FAST/FREAK 4=FAST/BRIEF 5=GFTT/FREAK 6=GFTT/BRIEF(default) 7=BRISK 8=GFTT/ORB 9=KAZE-->
<param name="Grid/FromDepth" type="string" value="true"/> <!--suppress warning (subscribe_scan=true)-->
<param name="RGBD/ProximityPathMaxNeighbors" type="string" value="1"/> <!--suppress warning (subscribe_scan = true and Reg/Strategy=1-->
<param name="Vis/FeatureType" type="string" value="6"/> <!--suppress warning,want to be same as KP/detectorstrategy -->
<param name="Icp/VoxelSize" type="string" value="0.1"/>
<param name="Icp/MaxCorrespondenceDistance" type="string" value="0.15"/>
<param name="Icp/Iterations" type="string" value="10"/>
<param name="Icp/Epsilon" type="string" value="0.001"/>
</node>
<!-- Visualisation RTAB-Map -->
<node pkg="rtabmap_ros" type="rtabmapviz" name="rtabmapviz" args="-d $(arg gui_cfg)" output="$(arg output)" launch-prefix="$(arg launch_prefix)">
<param name="subscribe_rgbd" type="bool" value="true"/>
<param name="subscribe_scan_cloud" type="bool" value="true"/>
<param name="frame_id" type="string" value="base_link"/>
<param name="odom_frame_id" type="string" value=""/>
<param name="wait_for_transform_duration" type="double" value="0.2"/>
<param name="queue_size" type="int" value="10"/>
<param name="approx_sync" type="bool" value="true"/>
<remap from="rgbd_image" to="rgbd_image"/>
<remap from="scan_cloud" to="/os1_cloud_node/points"/>
<remap from="odom" to="/odom"/>
</node>
<node pkg="tf" type="static_transform_publisher" name="base_to_laser"
args="0.1 0.0 0.0 0 0 0 /base_link /laser 100" />
<node pkg="tf" type="static_transform_publisher" name="base_to_cam"
args="0.18 0.0 0.0 0 0 0 /base_link /camera_link 100" />
</group>
</launch>
cheers, Mathieu |
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Hi Mathieu,
Thank you for the response. How would I remove any mention of 2D Lidar? My application only has a realsense and the Ouster Lidar (and on-board imu/odom). I think the inclusion of 2D Lidar references is creating a mixup in the launch file. Also, do I need to modify my tf for the base_link_laser to a different keyword if my Lidar is 3D, not 2D? Thanks! |
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Administrator
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Hi,
In the example in my previous post, there is no reference to 2D lidar. Not sure what you are referring. For 2D lidar, we use: <param name="subscribe_scan" value="true"/> <remap from="scan" to="/scan"/> <!-- sensor_msgs/LaserScan, assuming horizontal orientation -->For 3D lidar, we use: <param name="subscribe_scan_cloud" value="true"/> <remap from="scan_cloud" to="/os1_cloud_node/points"/> <!-- sensor_msgs/PointCloud2 --> For the last question, the TF name used for the lidar frame can be anything, there is no difference between 2d or 3d there. cheers, Mathieu |
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