agv_navigation_ws/costmap_2d/launch/example.launch

<launch>
  <!-- 
  NOTE: You'll need to bring up something that publishes sensor data (see
  rosstage), something that publishes a map (see map_server), and something to
  visualize a costmap (see nav_view), to see things work.

  Also, on a real robot, you'd want to set the "use_sim_time" parameter to false, or just not set it.
  -->
  <param name="/use_sim_time" value="true"/>

  <!-- Publishes the voxel grid to rviz for display -->
  <node pkg="costmap_2d" type="costmap_2d_markers" name="voxel_visualizer">
    <remap from="voxel_grid" to="costmap/voxel_grid"/>
  </node>

  <!-- Run the costmap node -->
  <node name="costmap_node" pkg="costmap_2d" type="costmap_2d_node" >
    <rosparam file="$(find costmap_2d)/launch/example_params.yaml" command="load" ns="costmap" />
  </node>

</launch>