Using rqt consol and roslaunch

Using rqt_consol and roslaunch

If you have not installed the turtle sim and rqt packages do so before continuing:

  sudo apt-get install ros-hydro-rqt ros-hydro-rqt-common-plugins ros-hydro-turtlesim

1) In a terminal, start roscore:

  roscore

1) In a new terminal (terminal 2), start the ros_console:

  rosrun rqt_console rqt_console

A window will pop up.

2) In a new terminal (terminal 3) begin the logger:

  rosrun rqt_logger_level rqt_logger_level

A window will pop up.

3) In a new terminal (terminal 4) begin the turtle simulation:

  rosrun turtlesim turtlesim_node

4) Change the logger level to Warn by refreshing the nodes in the rqt_logger_level window and selecting Warn.

5) In a new terminal (terminal 5) send a command to the sim:

  rostopic pub /turtle1/cmd_vel geometry_msgs/Twist -r 1 -- '[2.0, 0.0, 0.0]' '[0.0, 0.0, 0.0]'

The logger will begin to print several warnings as expected.

6) Kill the simulation. Close terminal 5. Navigate to the beginners_tutorial package:

  roscd beginner_tutorials

6b) If roscd says similar to roscd: No such package/stack 'beginner_tutorials' , you will need to source the environment

  cd ~/catkin_ws
   source devel/setup.bash
   roscd beginner_tutorials

This must be done for each terminal you use

7) Make a launch directory:

  mkdir launch
   cd launch

8) Create a newe file titled turtlemimic.launch and paste in the following:

  <launch>
   
     <group ns="turtlesim1">
       <node pkg="turtlesim" name="sim" type="turtlesim_node"/>
     </group>
   
     <group ns="turtlesim2">
       <node pkg="turtlesim" name="sim" type="turtlesim_node"/>
     </group>
   
     <node pkg="turtlesim" name="mimic" type="mimic">
       <remap from="input" to="turtlesim1/turtle1"/>
       <remap from="output" to="turtlesim2/turtle1"/>
     </node>
   
   </launch>

9) In terminal 4, use roslaunch [package] [filename.launch] to run launch files that contain nodes:

  roslaunch beginner_tutorials turtlemimic.launch

Two turtlesims will appear.

10) In a new terminal (terminal 5) send a command to the first simulation:

  rostopic pub /turtlesim1/turtle1/cmd_vel geometry_msgs/Twist -r 1 -- '[2.0, 0.0, 0.0]' '[0.0, 0.0, -1.8]'

The command sent to the first turtle is mimicked by the second.