Added a launch file for the simulation.

launch/visual_gps_sim.launch

+<launch>
+
+  <node pkg="nodelet" type="nodelet" name="visual_gps_nodelet"  args="manager" output="screen">
+    
+  </node>
+
+  <node pkg="nodelet" type="nodelet" name="blob_detector_color1" args="load iri_blob_detector/BlobDetectorNodelet visual_gps_nodelet" output="screen">
+    <remap from="~/image_in/image_raw" to="/usb_cam/image_raw"/>
+    <remap from="~/image_in/camera_info" to="/usb_cam/camera_info"/>
+    <remap from="~/blobs" to="/visual_gps/color1_blobs"/>
+    <rosparam file="$(find iri_visual_gps)/config/green_conf.yaml" command="load" />
+  </node>
+  <node pkg="nodelet" type="nodelet" name="blob_detector_color2" args="load iri_blob_detector/BlobDetectorNodelet visual_gps_nodelet" output="screen">
+    <remap from="~/image_in/image_raw" to="/usb_cam/image_raw"/>
+    <remap from="~/image_in/camera_info" to="/usb_cam/camera_info"/>
+    <remap from="~/blobs" to="/visual_gps/color2_blobs"/>
+    <rosparam file="$(find iri_visual_gps)/config/red_conf.yaml" command="load" />
+  </node>
+  <node pkg="nodelet" type="nodelet" name="blob_detector_color3" args="load iri_blob_detector/BlobDetectorNodelet visual_gps_nodelet" output="screen">
+    <remap from="~/image_in/image_raw" to="/usb_cam/image_raw"/>
+    <remap from="~/image_in/camera_info" to="/usb_cam/camera_info"/>
+    <remap from="~/blobs" to="/visual_gps/color3_blobs"/>
+    <rosparam file="$(find iri_visual_gps)/config/yellow_conf.yaml" command="load" />
+  </node>
+  <node pkg="nodelet" type="nodelet" name="blob_detector_color4" args="load iri_blob_detector/BlobDetectorNodelet visual_gps_nodelet" output="screen">
+    <remap from="~/image_in/image_raw" to="/usb_cam/image_raw"/>
+    <remap from="~/image_in/camera_info" to="/usb_cam/camera_info"/>
+    <remap from="~/blobs" to="/visual_gps/color4_blobs"/>
+    <rosparam file="$(find iri_visual_gps)/config/blue_conf.yaml" command="load" />
+  </node>
+
+  <node pkg="iri_visual_gps" 
+        type="iri_visual_gps" 
+        name="visual_gps" 
+        output="screen">
+    <remap from="~/camera/camera_info" to="/usb_cam/camera_info"/>
+    <remap from="~/set_camera_params" to="/usb_cam/set_parameters"/>
+    <rosparam file="$(find iri_visual_gps)/config/sim_position.yaml" command="load" />
+  </node>
+</launch>