I have been having a very difficult time trying to understand why my system does not have the cmd_vel topic. I am trying to get a ROS system running with Gazebo so that I can work through tutorials and learn ROS. I started with the ROS Development Studio (online) and it was great! But sooner or later one must be able to get ROS going on a local system. So I built a Ubuntu system and installed ROS + Gazebo, then installed Turtlebot including the simulator. It all works! I can launch a Turtlebot simulation then launch the Turtlebot_teleop package and I am able to move the robot around.
But when I list the running topics cmd_vel is not one of them. These are the list of topics grep'd on "cmd":
scott@Ubvm:~/catkin_ws/devel$ rostopic list | grep cmd /cmd_vel_mux/active /cmd_vel_mux/input/navi /cmd_vel_mux/input/safety_controller /cmd_vel_mux/input/switch /cmd_vel_mux/input/teleop /cmd_vel_mux/parameter_descriptions /cmd_vel_mux/parameter_updates
No /cmd_vel! So I can't work through tutorials to drive the robot around. Besides, I just don't understand why it is not there but teleop works.
Could someone tell me why I do not see the cmd_vel topic?
Gazebo 7 (not sure exactly which version but it launches and runs)
Installed Turtlebot based on Indigo install but replaced with kinetic.
sudo apt-get install ros-kinetic-turtlebot ros-kinetic-turtlebot-apps ros-kinetic-turtlebot-interactions ros-kinetic-turtlebot-simulator ros-kinetic-kobuki-ftdi ros-kinetic-rocon-remocon ros-kinetic-rocon-qt-library ros-kinetic-ar-track-alvar-msgs