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ankitdhall / lidar_camera_calibration

ROS package to find a rigid-body transformation between a LiDAR and a camera for "LiDAR-Camera Calibration using 3D-3D Point correspondences"
http://arxiv.org/abs/1705.09785
GNU General Public License v3.0
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lidar_camera_calibration_rt topic has no publisher #6

Closed zachkendrick closed 7 years ago

zachkendrick commented 7 years ago

I think I have found the reason why it is hanging but I don't know how to fix it. The callback function in find_velodyne_points.cpp subscribes to the topic "lidar_camera_calibration_rt" but this topic has no publisher when I do $ rostopic info /lidar_camera_calibration_rt. I am assuming the topic /aruco_poses should publish to it but that topic is currently publishing a completely different type (aruco_mapping/ArucoMarker). Any thoughts?

zachkendrick commented 7 years ago

I found the correct aruco_mapping files that contain the correct publisher here:

http://mirror-eu.docs.ros.org/latest-lts/api/lidar_camera_calibration/html/dir_03b35d6ddc8b0dcc071773c41473f2e5.html

I think the link to the aruco_mapping in the README is incorrect... let me know if I am right or wrong.

ankitdhall commented 7 years ago

@zachkendrick the dependencies are available in the lidar_camera_calibration/dependencies folder. The readme mentions that aruco_mapping has been modified slightly and publishes the lidar_camera_calibration_rt topic. You will find more information in the Setup section in the readme.

villanuevab commented 6 years ago

I checked the velodyne points timestamps and camera timestamps, but the approximate time synchronizer's callback is never called. I am assuming this is related to this issue. When I run rostopic list, I don't see any lidar_camera_calibration_rt topic.

[UPDATE]: Have since created a short script to see if the topics can be synchronized (subscribe to the same topics using python's ApproximateTimeSync), and the messages can be synced... despite this, I can't get the ApproximateTimeSync callback to be called via aruco_mapping. Any other hypotheses for this issue...?

karnikram commented 6 years ago

@villanuevab Are you checking the timestamps of the lidar_camera_calibration::marker_6dof msgs and the velodyne's PointCloud2 messages? They should approximately match.

The marker_6dof msgs are published by dependencies/aruco_mapping on the lidar_camera_calibration_rt topic.

chenwinki commented 5 years ago

@villanuevab Hi, How did you deal with "ApproximateTimeSync callback can't be call" this problem? I met the same problem. Hope for reply.