ifly/line_follower/launch/line_follow_control.launch

<launch>
  <!-- Start line_follow_debug.launch separately.  This file starts no camera. -->
  <arg name="config" default="$(find line_follower)/config/line_follow_control.yaml"/>
  <arg name="enabled" default="false"/>

  <node pkg="line_follower" type="line_follow_control.py" name="line_follow_control" output="screen">
    <rosparam command="load" file="$(arg config)"/>
    <param name="enabled" value="$(arg enabled)"/>
  </node>
</launch>