add world and launch file for LIP simulation.

hrpsys_gazebo_tutorials/launch/gazebo_lip.launch

@@ -0,0 +1,8 @@
+<launch>
+  <arg name="paused" default="false"/>
+
+  <include file="$(find gazebo_ros)/launch/empty_world.launch">
+    <arg name="world_name" value="$(find hrpsys_gazebo_tutorials)/worlds/LIP.world" />
+    <arg name="paused" value="$(arg paused)"/>
+  </include>
+</launch>

hrpsys_gazebo_tutorials/worlds/LIP.world

@@ -0,0 +1,37 @@
+<?xml version="1.0" ?>
+<!-- This is a source file of world. -->
+<!-- Do not edit this file. -->
+<sdf version="1.4">
+  <world name="default">
+    <physics type="ode">
+      <gravity>0 0 -9.81</gravity>
+      <ode>
+        <solver>
+          <type>quick</type>
+          <iters>50</iters>
+          <sor>1.4</sor>
+        </solver>
+        <constraints>
+          <cfm>0.0</cfm>
+          <erp>0.2</erp>
+          <contact_max_correcting_vel>100.0</contact_max_correcting_vel>
+          <contact_surface_layer>0.0</contact_surface_layer>
+        </constraints>
+      </ode>
+      <real_time_update_rate>1000</real_time_update_rate>
+      <max_step_size>0.001</max_step_size>
+    </physics>
+    <!-- A global light source -->
+    <include>
+      <uri>model://sun</uri>
+    </include>
+    <!-- A ground plane -->
+    <include>
+      <uri>model://ground_plane</uri>
+    </include>
+    <!-- A robot -->
+    <include>
+      <uri>model://LIP</uri>
+    </include>
+  </world>
+</sdf>