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TF2 exception warning

asked 2016-04-26 02:05:45 -0500

soichirutk gravatar image

Hi I trying to use some examples with this packages packages getting this warning [ WARN] [1461653020.332402156]: TF2 exception: Lookup would require extrapolation into the future. Requested time 1461653020.318166665 but the latest data is at time 1461653020.303369825, when looking up transform from frame [camera_depth_optical_frame] to frame [camera_rgb_optical_frame], so I checked the rqt_graph and is something rqt_tf_tree

, but I don't known why is this warning and wiht the command roswtf I get :

Found 1 warning(s). Warnings are things that may be just fine, but are sometimes at fault

WARNING The following node subscriptions are unconnected: * /camera/camera_nodelet_manager: * /tf_static

Thank you and best regards

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answered 2016-04-26 02:28:22 -0500

The warning means that you asked TF for a transform, but the TF listener doesn't have that transform in its buffer yet. In other words, the message you're trying to transform (probably a point cloud, image or depth image) has the time stamp 1461653020.318166665 and has arrived before the corresponding transform. The latest transform that is known to the TF listener has time stamp 1461653020.303369825 (that's 0.01 s earlier).

The solution is to add a waitForTransform before the lookupTransform, as explained in this tutorial.

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Thank you for the answer, but in the node files I use, theres is no transformations, that is why I don't see where I have to add the solution that you propose. Also I don't know if beacuse of this warning the output images in RGB don't appear. It would be better to post an rqt_graph?

soichirutk gravatar image soichirutk  ( 2016-04-26 11:22:28 -0500 )edit

I couldn't find any tf transformations in the repo you linked either. It would be helpful if you could add more information to your question, such all nodes that you're starting etc.; also, if you run this command in all terminals before starting any nodes, the log output will include...

Martin Günther gravatar image Martin Günther  ( 2016-04-27 03:35:41 -0500 )edit

... the name of the node that threw the error: export ROSCONSOLE_FORMAT=[${severity}] [${time}]: ${message} (${node})

Martin Günther gravatar image Martin Günther  ( 2016-04-27 03:36:15 -0500 )edit

Thank you for your help I'll check what you mentioned, and about what I'm using from the link is the launch file run_kinect_CodeSprint_bis.launch, and it just require the packages object_tracking, HaarDispAda, ground_based_detector, roiViewer. Another fact is that I'm using ROS indigo so

soichirutk gravatar image soichirutk  ( 2016-04-27 10:21:50 -0500 )edit

I had to change the manifest.xml eliminating <depend package="opencv2"/>, and at the CMakeLists.txt added find_package(OpenCV REQUIRED) , include_directories(${OpenCV_INCLUDE_DIRS}), target_link_libraries(${PROJECT_NAME} ${OpenCV_LIBRARIES}).

soichirutk gravatar image soichirutk  ( 2016-04-27 10:31:17 -0500 )edit

Hi again, well with ROSCONSOLE_FORMAT the node that is sending this warning is (/camera/camera_nodelet_manager), so it is something about the Kinect

soichirutk gravatar image soichirutk  ( 2016-04-27 13:03:12 -0500 )edit

Does it also happen if you only do roslaunch openni_launch openni.launch directly?

Martin Günther gravatar image Martin Günther  ( 2016-04-28 04:55:31 -0500 )edit

No, but if I try this rosrun image_view disparity_view image:=/camera/depth/disparity I get this error QMetaMethod::invoke: Unable to invoke methods with return values in queued connections, something has to be with Opencv I'm working on that issue, thanks for your help..

soichirutk gravatar image soichirutk  ( 2016-04-28 10:14:55 -0500 )edit

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Asked: 2016-04-26 02:05:45 -0500

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Last updated: Apr 26 '16