I am currently using RealSense L515 and successfully build rtabmap-ros and rtabmap then this problem occur.

[JerryMelv]

Hello fellow RTAB-Map Devs,
I am using RealSense L515 with a library from librealsense and realsense-ros. ROS humble is utilized in this project and when i tried to launch rtabmap this warning. Is there any way to evade this warning? I tried align_depth:=true and nothing happen. I also tried to set approx_sync to false but the problem is still there. Then i checked the hz using "ros2 topic hz /camera/color/image_raw" and "ros2 topic hz /camera/depth/image_rect_raw" and found out that both of the hz has similar value (although it sometimes goes up and down) but it has the average of around 30.



Your help will be appreciated.

[matlabbe]

Hi,

That warning says that the synchronized topics have large difference in time, so results would be less accurate because of this.

You may try setting "approx_sync_max_interval" smaller than 0.01 to sync only frames that are close in time and reject those with large difference. Otherwise, to remove that warning you would need to change the code as the threshold is hard-coded:
https://github.com/introlab/rtabmap_ros/blob/7d84f83d96fbb4e3f9bb4794275504c176feaca8/rtabmap_sync/src/nodelets/rgbd_sync.cpp#L154

cheers,
Mathieu