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lwheel and rwheel frame to link up to URDF

asked 2017-02-12 15:48:09 -0600

burf2000 gravatar image

updated 2017-02-13 02:19:34 -0600

So, this seem to be the final thing I am stuck on, please help

My wheels in my URDF is lwheel and rwheel

When I list topics, the wheels are listed


When I do rosrun tf view_frames

Exception thrown:"odom" passed to lookupTransform argument source_frame does not exist.  
The current list of frames is: 
Frame laser exists with parent base_frame. 
Frame base_frame exists with parent map. 
Frame scanmatcher_frame exists with parent

What the hell do I need to map these so the URDF maps to the publisher? I think its something to do with a TF?

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If you have a URDF describing the geometry of your robot (e.g. the transform between base_link and lwheel) then you likely need to be running an instance of the robot_state_publisher which publishes the /tf data between the links in a URDF

jarvisschultz gravatar image jarvisschultz  ( 2017-02-13 07:41:40 -0600 )edit

First thank you for answer, you rock. My base_link is actually base_frame (seems Hector Mapping uses that) however everything is linked (base_frame, lwheel, rwheel, laser etc) Laser and Base_frame come up fine in RVIZ. lwheel, rwheel do not? ]

burf2000 gravatar image burf2000  ( 2017-02-13 07:58:23 -0600 )edit

Do lwheel and rwheel have non-fixed joints? For example continuous rotation joints about the axle axis? If so, something needs to publish a sensor_msgs/JointState message, typically on the /joints_states topic, containing these angles

jarvisschultz gravatar image jarvisschultz  ( 2017-02-13 08:25:39 -0600 )edit

You may be interested in using the joint_state_publisher to help get these values published.

jarvisschultz gravatar image jarvisschultz  ( 2017-02-13 08:26:28 -0600 )edit

I was following the URDF tutorial and so the wheels are just connected to the Base_frame

burf2000 gravatar image burf2000  ( 2017-02-13 08:28:09 -0600 )edit

Tonight I will try the code again with <node name="robot_state_publisher" pkg="robot_state_publisher" type="state_publisher"/>

burf2000 gravatar image burf2000  ( 2017-02-13 08:28:50 -0600 )edit

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answered 2017-02-18 02:01:35 -0600

burf2000 gravatar image

So the bit I needed to add as mentioned above was:

<node pkg="robot_state_publisher" type="robot_state_publisher" name="robot_state_publisher"> </node>

This seems to advertises the parts of the robot URDF(joints etc) to RVIZ. The errors went away

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Asked: 2017-02-12 15:48:09 -0600

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Last updated: Feb 18 '17