Could not convert laser scan msg! Aborting rtabmap update...

[floda]

Salut, i dont find the quirk in my setup. It is reporting transform errors from base_link to laser_frame

[ERROR] [1617422472.283590916]: Could not convert laser scan msg! Aborting rtabmap update...
[ WARN] [1617422473.242588549]: Could not get transform from base_link to laser_frame after 0.200000 seconds (for stamp=1744622472.894362)! Error="Lookup would require extrapolation into the future.  Requested time 1744622472.894362000 but the latest data is at time 1617422473.156730727, when looking up transform from frame [laser_frame] to frame [base_link]. canTransform ret
[ WARN] [1617422474.268772179]: Could not get transform from base_link to laser_frame after 0.200000 seconds (for stamp=1744822465.913362)! Error="Lookup would require extrapolation into the future.  Requested time 1744822465.913362000 but the latest data is at time 1617422474.156728727, when looking up transform from frame [laser_frame] to frame [base_link]. canTransform returned after 0.200662 timeout was 0.2.".

I dont find the explaination why the request and actual time is 127399991 seconds apart.

tf_monitor reports the following:

RESULTS: for all Frames

Frames:
Frame: base_link published by unknown_publisher Average Delay: 0.672061 Max Delay: 1.10851
Frame: laser_frame published by unknown_publisher Average Delay: -0.0091862 Max Delay: 0
Frame: odom published by unknown_publisher Average Delay: 0.672083 Max Delay: 1.10852
Frame: zed_baro_link published by unknown_publisher(static) Average Delay: 0 Max Delay: 0
Frame: zed_camera_center published by unknown_publisher Average Delay: -0.0092139 Max Delay: 0
Frame: zed_left_camera_frame published by unknown_publisher(static) Average Delay: 0 Max Delay: 0
Frame: zed_left_camera_optical_frame published by unknown_publisher(static) Average Delay: 0 Max Delay: 0
Frame: zed_mag_link published by unknown_publisher(static) Average Delay: 0 Max Delay: 0
Frame: zed_right_camera_frame published by unknown_publisher(static) Average Delay: 0 Max Delay: 0
Frame: zed_right_camera_optical_frame published by unknown_publisher(static) Average Delay: 0 Max Delay: 0
Frame: zed_temp_left_link published by unknown_publisher(static) Average Delay: 0 Max Delay: 0
Frame: zed_temp_right_link published by unknown_publisher(static) Average Delay: 0 Max Delay: 0

All Broadcasters:
Node: unknown_publisher 220.553 Hz, Average Delay: 0.0672988 Max Delay: 1.10852
Node: unknown_publisher(static) 1e+08 Hz, Average Delay: 0 Max Delay: 0

<launch>
  <!-- launch zed and rtabmap -->

  <include file="$(find zed_rtabmap_example)/launch/rtbot_zed_rtabmap.launch" />

  <node pkg="tf" type="static_transform_publisher" name="base_link_TO_zed_camera_center" args="0 0 0.5 0 0 0 base_link zed_camera_center 10"/>
  <node pkg="tf" type="static_transform_publisher" name="base_link_TO_laser" args="-0.20 -0.12 0.55 3.14159 0.0  0.0 base_link laser_frame 10" />

</launch>

Any idea welcome. Thanks in advance

[matlabbe]

Hi,

Is the lidar published by another computer? Make sure to synchronize the clock (ntpdate) between the computers.

You can also show the TF tree to better see the time differences between frames.

rosrun tf2_tools view_frames.py

If you are replaying a bag, don't forget to set use_sim_time to true and launch bag with --clock.

cheers,
Mathieu

[floda]

Thx Mathieu,

All is on same system and in libe mode. I suspect now the ydlidar node and that disagreement in tf stamps when using two sensors.
Rtabmapd does not complain about when just having the zed sensor.

Ill post my success or unsuccess.