Added a launch file to simulate the robot on top of a platform with 2 degrees of freedom.

darwin_apps/launch/darwin_eq.launch

+<launch>
+
+  <arg name="robot" default="darwin_cpp" />
+
+  <include file="$(find darwin_description)/launch/darwin_sim.launch">
+    <arg name="robot" value="$(arg robot)" />
+  </include>
+
+  <group ns="platform">
+    <include file="$(find eq_platform_description)/launch/eq_platform.launch">
+    </include>
+  </group> 
+ 
+</launch>

darwin_gazebo/launch/darwin.launch

@@ -14,7 +14,7 @@
   </include>
 
   <!-- Spawn a robot into Gazebo -->
-  <node name="spawn_urdf" pkg="gazebo_ros" type="spawn_model" args="-param robot_description -urdf -model darwin -x 0 -y 0 -z 0.4 -R 1.6 -P 0 -Y 0" />
+  <node name="spawn_urdf" pkg="gazebo_ros" type="spawn_model" args="-param robot_description -urdf -model darwin -x 0 -y 0 -z 0.49 -R 1.6 -P 0 -Y 0" />
   
 </launch>