Hey Jeff, I can't answer all of your questions, but robot_state_publisher always flattens the tree. I assume it's for computational efficiency. -David!! On Mon, Sep 20, 2010 at 1:55 PM, Jeff Rousseau wrote: > Hi All, > > Attached is the output of 'rosrun tf view_frames' showing the > transforms being published by robot_state_publisher based on the URDF > for my iRobot Create (also attached) as well the output of "rosrun > urdf urdf_to_graphiz irobot_create_full.urdf.xacro" showing the links > and joints that make up my URDF. > > I'm a bit confused as to why these two trees don't match. Why is > 'robot_state_publisher' flattening the URDF tree and rearranging some > connections when outputting to TF? According to the URDF base_link > should be the parent of base_link_left/right_motor_link and the motor > links should be the parent of the wheel links... > > I think this is related, but not entirely sure: when I add the model > to rviz I get the following warnings: > ---------- > caster_wheel_link > No transform from [caster_wheel_link] to [/map] > > base_caster_support_link > No transform from [base_caster_support_link] to [/map] > ---------- > > Any input, ideas as to whats going wrong/what I'm doing wrong? > (my guess is that I'm making an incorrect assumption that there is a > 1-to-1 correspondence between how gazebo and ros handle coordinate > frames) > > PS on a slightly unrelated note: tf_frames.pdf shows gazebo publishing > the /odom topic at 100hz, is there a way to change this rate? I'm > trying to squeeze as many cycles out of my old hardware as I can, so > I'm trying to avoid over-publishing on my topics to cut down CPU usage > (as it is now gazebo in 'top' is claiming 90-100% of my cpu).  I tried > adding a < param name="publish_frequency" type="double" value="10.0" > /> to fake_localization node in my launch file, but it didn't take... > > Jeff > > _______________________________________________ > ros-users mailing list > ros-users@code.ros.org > https://code.ros.org/mailman/listinfo/ros-users > >