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frame_id and child_frame_id for robot_pose_ekf

asked 2014-06-12 16:21:08 -0600

fyxbird gravatar image

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.

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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) ?

al-dev gravatar image al-dev  ( 2014-06-12 23:03:32 -0600 )edit

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.

fyxbird gravatar image fyxbird  ( 2014-06-13 05:07:20 -0600 )edit

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" ?

al-dev gravatar image al-dev  ( 2014-06-13 05:36:54 -0600 )edit

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.

fyxbird gravatar image fyxbird  ( 2014-06-13 05:45:40 -0600 )edit

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 : You might want to follow the other RobotSetup tutorial as well, they are pretty detailed.

al-dev gravatar image al-dev  ( 2014-06-13 07:19:59 -0600 )edit

I will try that, thanks, al-dev.

fyxbird gravatar image fyxbird  ( 2014-06-13 08:23:50 -0600 )edit

Hey fyxbird, did you solve your problem? If so, don't forget to mark the answer for the other users.

al-dev gravatar image al-dev  ( 2014-06-16 10:24:45 -0600 )edit

Hi, al-dev, I haven't work on that for the last two days. I will try and respond to this quesiton. Thanks.

fyxbird gravatar image fyxbird  ( 2014-06-16 10:56:16 -0600 )edit

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answered 2014-06-25 10:18:45 -0600

fyxbird gravatar image

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.

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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

bikram.adhikari gravatar image bikram.adhikari  ( 2015-04-17 06:06:47 -0600 )edit

Hi, bikram, As I have already finished that project, I don't have access to the equipment now. But I remember the tf tree is something looks like this. What's ur problem, maybe I can help you with it. /robot_pose_ekf/odom

   /odometry      /imu_data      /gps
fyxbird gravatar image fyxbird  ( 2015-04-17 08:49:25 -0600 )edit

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

Anirvan0102 gravatar image Anirvan0102  ( 2016-06-07 08:16:39 -0600 )edit

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.

fyxbird gravatar image fyxbird  ( 2016-06-08 04:48:59 -0600 )edit

Hello, I am also a new ros, I am also using ekf positioning, my input is /rf2o_laser_odometry/odom and /imu_data, I would like to ask fyxbird you use imu_filter_madgwick to filter the imu_data, if there is any filter and ekf filter Difference, thank you

fofMobius gravatar image fofMobius  ( 2019-05-23 10:23:28 -0600 )edit

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Asked: 2014-06-12 16:21:08 -0600

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Last updated: Jun 25 '14