Okay, so we are done with simulating a complete robotic car in Gazebo; now, let's move the robot around the environment. We can do this using a keyboard teleop node.

We can launch an existing TurtleBot teleop node using the following command:

    $ roslaunch turtlebot_teleop keyboard_teleop.launch

The TurtleBot teleop node is publishing Twist messages to /cmd_vel_mux/input/teleop, and we need to convert them into /catvehicle/cmd_vel.

The following command can do this conversion:

    $ rosrun topic_tools relay /cmd_vel_mux/input/teleop /catvehicle/cmd_vel

Now, you can move the car around the environment using the keyboard. This will be useful while we perform SLAM.