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Does the turtlebot need wifi access to build a map?

asked 2012-02-09 11:15:55 -0500

updated 2012-02-09 11:16:36 -0500

Does the turtlebot actually need a wifi connection to operate? I want to build a map of a large area in my office building. The building has wifi coverage, but it is spotty and sometimes the connection gets dropped.

I would like to drive the turtlebot around with a wireless joystick, and build a map using the gmapping tutorial. My question is, if the turtlebot's netbook loses the wireless connection along the way, will this cause problems with the processes?

Basically, I want to: 1) bringup the turtlebot 2) start the gmapping app: roslaunch turtlebot_navigation gmapping_demo.launch 3) Check from the workstation that the dashboard is ok (and then close it). 4) Start the joystick telop and drive around and build the map.

I am worried that if the wireless connection is dropped while I am driving it around to build the map, that ROS_HOSTNAME and ROS_MASTER_URI will no longer resolve on the turtlebot and the map app will fail.

Please let me know if there are any tricks to building a map like this, or if I am going about it incorrectly. It tried a short mapping experiment using key teleoperation from the workstation, and that failed when the connection was dropped. So, I am trying to understand the requirements better.


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answered 2012-02-09 13:54:28 -0500

If you run all of the processes on the turtlebot itself, you won't have any problems. It may be helpful to use gnu screen so your nodes don't die when the turtlebot loses its network connection and the SSH sessions disconnect.

Additionally, if the ROS_MASTER_URI is set to localhost, it does not matter if you actually have a network connection.

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answered 2012-02-15 03:57:16 -0500

Thanks, I followed your advice and using localhost for ROS_MASTER_URI on the robot works nicely. Gnu screen is very useful for keeping the processes running.

Also, when mapping, sometimes I prefer to follow the robot and stay connected via ethernet cable so I get fast updates in RViz. To do that, I followed the instructions from: Setup roscd turtlebot_bringup/upstart sudo eth0

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Asked: 2012-02-09 11:15:55 -0500

Seen: 584 times

Last updated: Feb 15 '12