Two Robots on a single Roscore

edit

Hello and happy new year :)

I am trying to run Peoplebot and Fetch on the same ROS master. I have attempted to use a tf_prefix so there wouldn't be a conflict in the TF tree. However, when I add the tf_prefix "peoplebot" to the global scope in peoplebot's launch file, I get this error:

[WARN [1483314575.427997796]: Timed out waiting for transform from peoplebot/base_link to map to become available before running costmap, tf error: . canTransform returned after 0.101242 timeout was 0.1.

My questions are:

1. Is tf_prefix the right approach for running multiple robots on a single core or is there a cleaner solution I'm overlooking?
2. Any suggestions how I can solve this problem? I've been jimmying around with my launch files for over 10 hours now with no avail..

Here is my tf tree before adding the prefix:

Here is my tf tree, now disconnected, after adding the global tf_prefix="peoplebot":

Also, I was able to get the tf tree connected by changing a few other things in the launch file, but still the map doesn't spawn:

Let me know if there's any other information I can provide. Thanks for your help :)