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Hi, guys. I am new to ROS. I am currently trying to use robot_pose_ekf to fuse data from odometry, imu and gps. But I can't get output from the EKF package. I think it might be caused by the issue of frame_id and child_frame_id after searching similar problems. But I don't know how to set the ids for my sensors. Can anyone help me with that. Thanks a lot.
The problem is solved, turns out that it is caused by the data published by gps is not time stamped. And the frame id of data from imu is wrong. Thx, al-dev.
Hi fyxbird, I am running through similar issue on robot_pose_ekf. Could you possibly post how your tf tree looks like after fixing the issue?
thanks, B
Hi, fyxbird, I am new to ROS and have similar issues. Could you tell me how to setup the tf for gps and imu. Thank You
Hi Anirvan,
I think in order to establish the tf tree, you need to make sure all gps and imu data are time stamped, and publish on specific topic in required format. You need to make sure your subscriber listens to the topic, and the data format correlates too. Regards.
Asked: 2014-06-12 16:21:08 -0500
Seen: 2,342 times
Last updated: Jun 25 '14
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Hi fyxbird, do you mean that you cannot get any output when you do "rostopic echo /robot_pose_ekf/odom_combined" or "rosrun tf tf_echo /world /tf_message" ? If so, have you checked that something is actually published on the topics robot_pose_ekf is listening to (/odom, /imu_data and /vo) ?
Hi al-dev, I am sure data are published on topics, odom. Imu_data and gps. When I use rostopic hz, I can get the publishing rate. And these data can be seen by echo. But when I echo odom_combined, these is nothing come out.
I guess the transform odom_combined → base_footprint isn't published either? Can you edit your subject to give the outputs of "rosrun tf view_frames" and "rosrun robot_pose_ekf wtf.py" ?
when I try rostopic list there are four topics related to imu, including imu_data. gps, odom_combined and odom are also existed. Along with two topics about tf. But no data in odom_combined and tf. when I try tf view_frames, there is no tree there. Besides, the data published by imu and gps have no frame_id, I think that might be the problem.
If you don't see any tree in view_frames, it could be that you are not publishing the transform configuration, as explained in this tutorial : http://wiki.ros.org/navigation/Tutorials/RobotSetup/TF. You might want to follow the other RobotSetup tutorial as well, they are pretty detailed.
I will try that, thanks, al-dev.
Hey fyxbird, did you solve your problem? If so, don't forget to mark the answer for the other users.
Hi, al-dev, I haven't work on that for the last two days. I will try and respond to this quesiton. Thanks.