TF do not display on move_group.launch

[Syafiq Nori]

Hello MoveIt! Users,

I have been experimenting with MoveIt! for a month now and i am finally starting figure something weird with my setup. As i launch the demo.launch and add the TF tab, i can see the whole tf tree of my robot.
And then i started to test MoveIt! with real robot and launch the move_group.launch . The motion planning and also execution was perfectly fine in Rviz. But as I add the TF tab, i can see now TF tree and there is a error message that tells the tf data are not
available. I can even see there is no tf tree in the move_group.launch.

Question:
1) Why did the tf in demo.launch works but in move_group.launch didn’t? What do i need to do to fix that?
2) Can the kinect data be published if the tf of the whole setup are messed up?

I am relatively new to ROS and MoveIt! and i hope you guys can bare with me if I am posting such a silly question.
I also attached the picture to  compare what happen  in Rviz between demo.launch and also move_group.launch (Rviz).
If you guys wanted to know more details, please let me know.

Any suggestion and tips would be really helpful.

Best regards,
Syafiq Nori

[Dave Hershberger]

move_group.launch is just one piece of demo.launch.  If you launch move_group.launch by itself you will need to duplicate several of the other parts of demo.launch.

 * joint_state_publisher is an important node that publishes TF frames based on robot joint angles.

 * static_transform_publisher publishes a static transform, often used to say where the robot's base link is relative to a world coordinate frame.

Usually when I need to run something similar to demo.launch but not the same (real robot, for example), I just copy and modify rather than starting over from scratch.

Dave

[Syafiq Nori]

Thank you Dave for your reply.

Can you attach an example of your launch file that contains the tf node and also static tf node? Maybe I can understand better with examples.
I also want to introduce kinect with the launch file to obtain octomap? Must I also specified the tf of the kinect in order to work?

Best regards,
Syafiq Nori

[Dave Hershberger]

The example launch file to look at is demo.launch which you already mentioned.

Yes, you'll need to specify the tf of the kinect to get it to work.

See also http://docs.ros.org/hydro/api/pr2_moveit_tutorials/html/planning/src/doc/perception_configuration.html for details about setting up live sensing.

Also if you have trouble with tf frames and trees, you can use "rosrun rqt_tf_tree rqt_tf_tree" (from package ros-hydro-rqt-tf-tree).

Dave