Two Robots on a single Roscore

Question

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 :)

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Originally posted by gsaba on ROS Answers with karma: 36 on 2017-01-01

Post score: 0

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Original comments

Comment by gvdhoorn on 2017-01-02:
Could you please make images of your pdfs and then attach them directly to this question? I've given you enough karma to make this possible. Reason I ask is because that will make this question self-contained, maintaining its value even if you delete the files from your google drive.

Thanks.

Comment by gsaba on 2017-01-02:
Thank you for the Karma. I have edited the post!

Cheers

Answer 1

Update: I was able to connect the graphs by adding a static transform from /map to peoplebot/odom (see image below)

I am now getting the errors:

[WARN] [1483387554.490771420]: The driver/sonar observation buffer has not been updated for 2.07 seconds, and it should be updated every 1.00 second.

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Originally posted by gsaba with karma: 36 on 2017-01-02

This answer was ACCEPTED on the original site

Post score: 1

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Original comments

Comment by ahendrix on 2017-01-02:
The transform from map to odom is traditionally provided by localization (AMCL), so you should probably try to figure out how to configure AMCL to publish that transform.

Comment by Will Chamberlain on 2018-01-03:
I am having the same problem with multi-robot navigation move_base: errors like "The robot1/scan observation buffer has not been updated for 56.86 seconds, and it should be updated every 0.40 seconds." Did you resolve this, and if so how? - link to example config files would be greatly appreciated!