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workstation multi-robot with rviz

asked 2015-02-12 05:37:08 -0600

florian2 gravatar image

updated 2015-02-12 06:09:17 -0600

Hi there !

We've got a problem ( my classmate and I) about the multi-robot supervision on Rviz. We would like to see 2 turtlebots on the workstation Rviz but we don't know if we have to do a .launch file where turtlebot commands and names are but we aren't sure. We think ROS_NAMESPACE could make a mistake on the network when we're trying to put 2 turtlebots on Rviz. For the moment, we use : roscore on the workstation. ROS_NAMESPACE=turtlebotX roslaunch turtlebot_bringup minimal.launch for each turtlebot, where X is a letter about a turtlebot ( turtlebotA, turtlebotB). ROS_NAMESPACE=turtlebotX roslaunch turtlebot_bringup 3dsensor.launch for each turtlebot. After this command, we've got a problem with warning flood on each prompt of turtlebot computer. They seems to be a warning about tf_old_data on the turtlebotB only.

roslaunch turtlebot_rviz_launchers view_robot.launch The workstation can control one of them but only if they're not connected at the same time on it. If A and B are connected, the workstation only see on Rviz the same turtlebot( in ur case, A). So maybe it's about alphabetical order and the workstation always store turtlebotA. We can see the turtlebot's camera and we can move it with teleop keyboard command. So, the real questions are : need a .launch? if yes, what kind of information do we write inside? does we make a mistake with command or forgot useful command to do?

Thanks for listening.

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answered 2015-03-11 08:44:20 -0600

florian2 gravatar image

We found the real problem thank to you. It was about the school's proxy who blocked port 123 allowing the update of time. The new problem is about Rviz and more precisely 'odom'. We have always 2 turtlebots connected on the workstation and we want to see both on Rviz but we don't know how to see them correctly. For the moment, Rviz get information of two turtlebots and think they are the same robot. Does we have to make launch and how exactly just for a example of 2 turtlebots? tf_frames could be one of the problem too?

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answered 2015-02-12 07:08:09 -0600

Wolf gravatar image

The ROS_NAMESPACE seems appropriate if using a common master for both multiple robots. You will have to set up an NTP connection ( ) for having tf working on multiple computers. Otherwise you will have this tf old data in any case because the tf frames published on one computer and subscribed on another have wrong time stamps because there clock are not in sync.

If you have that I am still not sure if ROS_NAMESPACE does also affect the tf frames? Maybe check that and have a look at tf_remap ( ).

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Asked: 2015-02-12 05:37:08 -0600

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Last updated: Mar 11 '15