Parameter server issues when started using rosinit

I have tried the following on two machines, one running MATLAB R2019a and ROS Melodic in Ubuntu 18.04 and one running MATALB R2019b in Windows 10 and ROS Melodic in Windows Subsystem for Linux with Ubuntu 18.04.

When I start a ROS master in MATLAB using

>> rosinit

and then, on the same computer, try to launch a TurtleBot3 rviz simulator using

$ roslaunch turtlebot3_fake turtlebot3_fake.launch

in a terminal, I get the error

[ERROR] [1580496484.938244857]: Could not find parameter robot_description on parameter server

[robot_state_publisher-2] process has died [pid 7590, exit code 1, cmd /opt/ros/melodic/lib/robot_state_publisher/robot_state_publisher __name:=robot_state_publisher __log:=/home/rushik/.ros/log/36c3cc86-445a-11ea-8c68-049226bf548f/robot_state_publisher-2.log].

log file: /home/rushik/.ros/log/36c3cc86-445a-11ea-8c68-049226bf548f/robot_state_publisher-2*.log

Instead, when I start the ROS master in a terminal using

$ roscore

and then launch the TurtleBot3 rviz simulator from another terminal, everything runs as expected.

Any ideas why the parameters are found on the server correctly when using roscore from a terminal but not when using rosinit from MATLAB?

Answer 1

[Cam Salzberger]

Hello Rushikesh,

I'm not sure about the cause of this specific error, but my money is on version incompatibility in the use of the parameter server between MATLAB and your ROS installation. MATLAB's ROS version supports Indigo and Hydro, but can't make an guarantees for other versions of ROS. Normally this just indicates a difference in message definitions, and you can overwrite those with the custom message support package. This seems to indicate an issue with the parameter server though.

If starting the Master/parameter server outside of MATLAB serves as a workaround for you, you can always connect to it from MATLAB by providing the Master URI to "rosinit". Otherwise, a quick search turned up several other people with this same error, and there may be suggestions there for modifying the XML file or launch arguments that would be compatible with the old version of the Master.

-Cam