Added a simple package to simulate a platform with 2 degrees of freedom.

eq_platform_description/CMakeLists.txt

+cmake_minimum_required(VERSION 2.8.3)
+project(eq_platform_description)
+
+## Compile as C++11, supported in ROS Kinetic and newer
+# add_compile_options(-std=c++11)
+
+## Find catkin macros and libraries
+## if COMPONENTS list like find_package(catkin REQUIRED COMPONENTS xyz)
+## is used, also find other catkin packages
+find_package(catkin REQUIRED)
+
+## System dependencies are found with CMake's conventions
+# find_package(Boost REQUIRED COMPONENTS system)
+
+
+## Uncomment this if the package has a setup.py. This macro ensures
+## modules and global scripts declared therein get installed
+## See http://ros.org/doc/api/catkin/html/user_guide/setup_dot_py.html
+# catkin_python_setup()
+
+################################################
+## Declare ROS messages, services and actions ##
+################################################
+
+## To declare and build messages, services or actions from within this
+## package, follow these steps:
+## * Let MSG_DEP_SET be the set of packages whose message types you use in
+##   your messages/services/actions (e.g. std_msgs, actionlib_msgs, ...).
+## * In the file package.xml:
+##   * add a build_depend tag for "message_generation"
+##   * add a build_depend and a exec_depend tag for each package in MSG_DEP_SET
+##   * If MSG_DEP_SET isn't empty the following dependency has been pulled in
+##     but can be declared for certainty nonetheless:
+##     * add a exec_depend tag for "message_runtime"
+## * In this file (CMakeLists.txt):
+##   * add "message_generation" and every package in MSG_DEP_SET to
+##     find_package(catkin REQUIRED COMPONENTS ...)
+##   * add "message_runtime" and every package in MSG_DEP_SET to
+##     catkin_package(CATKIN_DEPENDS ...)
+##   * uncomment the add_*_files sections below as needed
+##     and list every .msg/.srv/.action file to be processed
+##   * uncomment the generate_messages entry below
+##   * add every package in MSG_DEP_SET to generate_messages(DEPENDENCIES ...)
+
+## Generate messages in the 'msg' folder
+# add_message_files(
+#   FILES
+#   Message1.msg
+#   Message2.msg
+# )
+
+## Generate services in the 'srv' folder
+# add_service_files(
+#   FILES
+#   Service1.srv
+#   Service2.srv
+# )
+
+## Generate actions in the 'action' folder
+# add_action_files(
+#   FILES
+#   Action1.action
+#   Action2.action
+# )
+
+## Generate added messages and services with any dependencies listed here
+# generate_messages(
+#   DEPENDENCIES
+#   std_msgs  # Or other packages containing msgs
+# )
+
+################################################
+## Declare ROS dynamic reconfigure parameters ##
+################################################
+
+## To declare and build dynamic reconfigure parameters within this
+## package, follow these steps:
+## * In the file package.xml:
+##   * add a build_depend and a exec_depend tag for "dynamic_reconfigure"
+## * In this file (CMakeLists.txt):
+##   * add "dynamic_reconfigure" to
+##     find_package(catkin REQUIRED COMPONENTS ...)
+##   * uncomment the "generate_dynamic_reconfigure_options" section below
+##     and list every .cfg file to be processed
+
+## Generate dynamic reconfigure parameters in the 'cfg' folder
+# generate_dynamic_reconfigure_options(
+#   cfg/DynReconf1.cfg
+#   cfg/DynReconf2.cfg
+# )
+
+###################################
+## catkin specific configuration ##
+###################################
+## The catkin_package macro generates cmake config files for your package
+## Declare things to be passed to dependent projects
+## INCLUDE_DIRS: uncomment this if your package contains header files
+## LIBRARIES: libraries you create in this project that dependent projects also need
+## CATKIN_DEPENDS: catkin_packages dependent projects also need
+## DEPENDS: system dependencies of this project that dependent projects also need
+catkin_package(
+#  INCLUDE_DIRS include
+#  LIBRARIES eq_platform_description
+#  CATKIN_DEPENDS other_catkin_pkg
+#  DEPENDS system_lib
+)
+
+###########
+## Build ##
+###########
+
+## Specify additional locations of header files
+## Your package locations should be listed before other locations
+include_directories(
+# include
+# ${catkin_INCLUDE_DIRS}
+)
+
+## Declare a C++ library
+# add_library(${PROJECT_NAME}
+#   src/${PROJECT_NAME}/eq_platform_description.cpp
+# )
+
+## Add cmake target dependencies of the library
+## as an example, code may need to be generated before libraries
+## either from message generation or dynamic reconfigure
+# add_dependencies(${PROJECT_NAME} ${${PROJECT_NAME}_EXPORTED_TARGETS} ${catkin_EXPORTED_TARGETS})
+
+## Declare a C++ executable
+## With catkin_make all packages are built within a single CMake context
+## The recommended prefix ensures that target names across packages don't collide
+# add_executable(${PROJECT_NAME}_node src/eq_platform_description_node.cpp)
+
+## Rename C++ executable without prefix
+## The above recommended prefix causes long target names, the following renames the
+## target back to the shorter version for ease of user use
+## e.g. "rosrun someones_pkg node" instead of "rosrun someones_pkg someones_pkg_node"
+# set_target_properties(${PROJECT_NAME}_node PROPERTIES OUTPUT_NAME node PREFIX "")
+
+## Add cmake target dependencies of the executable
+## same as for the library above
+# add_dependencies(${PROJECT_NAME}_node ${${PROJECT_NAME}_EXPORTED_TARGETS} ${catkin_EXPORTED_TARGETS})
+
+## Specify libraries to link a library or executable target against
+# target_link_libraries(${PROJECT_NAME}_node
+#   ${catkin_LIBRARIES}
+# )
+
+#############
+## Install ##
+#############
+
+# all install targets should use catkin DESTINATION variables
+# See http://ros.org/doc/api/catkin/html/adv_user_guide/variables.html
+
+## Mark executable scripts (Python etc.) for installation
+## in contrast to setup.py, you can choose the destination
+# install(PROGRAMS
+#   scripts/my_python_script
+#   DESTINATION ${CATKIN_PACKAGE_BIN_DESTINATION}
+# )
+
+## Mark executables and/or libraries for installation
+# install(TARGETS ${PROJECT_NAME} ${PROJECT_NAME}_node
+#   ARCHIVE DESTINATION ${CATKIN_PACKAGE_LIB_DESTINATION}
+#   LIBRARY DESTINATION ${CATKIN_PACKAGE_LIB_DESTINATION}
+#   RUNTIME DESTINATION ${CATKIN_PACKAGE_BIN_DESTINATION}
+# )
+
+## Mark cpp header files for installation
+# install(DIRECTORY include/${PROJECT_NAME}/
+#   DESTINATION ${CATKIN_PACKAGE_INCLUDE_DESTINATION}
+#   FILES_MATCHING PATTERN "*.h"
+#   PATTERN ".svn" EXCLUDE
+# )
+
+## Mark other files for installation (e.g. launch and bag files, etc.)
+# install(FILES
+#   # myfile1
+#   # myfile2
+#   DESTINATION ${CATKIN_PACKAGE_SHARE_DESTINATION}
+# )
+
+#############
+## Testing ##
+#############
+
+## Add gtest based cpp test target and link libraries
+# catkin_add_gtest(${PROJECT_NAME}-test test/test_eq_platform_description.cpp)
+# if(TARGET ${PROJECT_NAME}-test)
+#   target_link_libraries(${PROJECT_NAME}-test ${PROJECT_NAME})
+# endif()
+
+## Add folders to be run by python nosetests
+# catkin_add_nosetests(test)

eq_platform_description/control/platform.yaml

+joint_state_controller:
+  type: joint_state_controller/JointStateController
+  publish_rate: 50
+
+platform_controller:
+  type: "effort_controllers/JointTrajectoryController"
+  joints:
+    - j_roll
+    - j_pitch
+  constraints:
+    goal_time: 0.5                   # Override default
+    stopped_velocity_tolerance: 0.02 # Override default
+    j_roll:
+      trajectory: 0.05               # Not enforced if unspecified
+      goal: 0.02                     # Not enforced if unspecified
+    j_pitch:
+      goal: 0.01                     # Not enforced if unspecified
+
+  gains: # Required because we're controlling an effort interface
+    j_roll: {p: 100,  d: 1, i: 1, i_clamp: 1}
+    j_pitch: {p: 100,  d: 1, i: 1, i_clamp: 1}
+
+  state_publish_rate:  25            # Override default
+  action_monitor_rate: 30            # Override default
+  stop_trajectory_duration: 0        # Override default

eq_platform_description/launch/eq_platform.launch

+<launch>
+
+  <!-- Convert an xacro and put on parameter server -->
+  <param name="robot_description"
+         command="$(find xacro)/xacro --inorder '$(find eq_platform_description)/urdf/eq_platform.urdf'" />
+
+  <!-- Load joint controller configurations from YAML file to parameter server -->
+  <rosparam file="$(find eq_platform_description)/control/platform.yaml" command="load"/>
+
+  <!-- load the controllers -->
+  <node name="controller_spawner"
+        pkg="controller_manager"
+        type="spawner"
+        respawn="false"
+        output="screen"
+        ns="/platform"
+        args="platform_controller joint_state_controller">
+  </node>
+
+  <!-- Spawn a robot into Gazebo -->
+  <node name="spawn_urdf" pkg="gazebo_ros" type="spawn_model" args="-param robot_description -urdf -model eq_platform -x 0 -y 0 -z 0 -R 0 -P 0 -Y 0" />
+
+</launch>
+

eq_platform_description/launch/eq_platform_test.launch

+<launch>
+
+  <!-- We resume the logic in empty_world.launch, changing only the name of the world to be launched -->
+  <include file="$(find gazebo_ros)/launch/empty_world.launch">
+    <arg name="world_name" value="$(find gazebo_ros)/worlds/empty.world"/>
+    <arg name="paused" value="true"/>
+    <!-- more default parameters can be changed here -->
+  </include>
+
+  <group ns="platform">
+    <include file="$(find eq_platform_description)/launch/eq_platform.launch">
+    </include>
+  </group>
+
+  <node name="rviz"
+        pkg="rviz"
+        type="rviz"
+        args="-d $(find eq_platform_description)/config/eq_platform_rviz.rviz" />
+</launch>
+

eq_platform_description/package.xml

+<?xml version="1.0"?>
+<package format="2">
+  <name>eq_platform_description</name>
+  <version>0.0.0</version>
+  <description>The eq_platform_description package</description>
+
+  <!-- One maintainer tag required, multiple allowed, one person per tag -->
+  <!-- Example:  -->
+  <!-- <maintainer email="jane.doe@example.com">Jane Doe</maintainer> -->
+  <maintainer email="shernand@todo.todo">shernand</maintainer>
+
+
+  <!-- One license tag required, multiple allowed, one license per tag -->
+  <!-- Commonly used license strings: -->
+  <!--   BSD, MIT, Boost Software License, GPLv2, GPLv3, LGPLv2.1, LGPLv3 -->
+  <license>TODO</license>
+
+
+  <!-- Url tags are optional, but multiple are allowed, one per tag -->
+  <!-- Optional attribute type can be: website, bugtracker, or repository -->
+  <!-- Example: -->
+  <!-- <url type="website">http://wiki.ros.org/eq_platform_description</url> -->
+
+
+  <!-- Author tags are optional, multiple are allowed, one per tag -->
+  <!-- Authors do not have to be maintainers, but could be -->
+  <!-- Example: -->
+  <!-- <author email="jane.doe@example.com">Jane Doe</author> -->
+
+
+  <!-- The *depend tags are used to specify dependencies -->
+  <!-- Dependencies can be catkin packages or system dependencies -->
+  <!-- Examples: -->
+  <!-- Use depend as a shortcut for packages that are both build and exec dependencies -->
+  <!--   <depend>roscpp</depend> -->
+  <!--   Note that this is equivalent to the following: -->
+  <!--   <build_depend>roscpp</build_depend> -->
+  <!--   <exec_depend>roscpp</exec_depend> -->
+  <!-- Use build_depend for packages you need at compile time: -->
+  <!--   <build_depend>message_generation</build_depend> -->
+  <!-- Use build_export_depend for packages you need in order to build against this package: -->
+  <!--   <build_export_depend>message_generation</build_export_depend> -->
+  <!-- Use buildtool_depend for build tool packages: -->
+  <!--   <buildtool_depend>catkin</buildtool_depend> -->
+  <!-- Use exec_depend for packages you need at runtime: -->
+  <!--   <exec_depend>message_runtime</exec_depend> -->
+  <!-- Use test_depend for packages you need only for testing: -->
+  <!--   <test_depend>gtest</test_depend> -->
+  <!-- Use doc_depend for packages you need only for building documentation: -->
+  <!--   <doc_depend>doxygen</doc_depend> -->
+  <buildtool_depend>catkin</buildtool_depend>
+
+
+  <!-- The export tag contains other, unspecified, tags -->
+  <export>
+    <!-- Other tools can request additional information be placed here -->
+
+  </export>
+</package>

eq_platform_description/urdf/eq_platform.urdf

+<robot name="eq_platform" xmlns:xacro="http://www.ros.org/wiki/xacro">
+
+  <link name="world"/>
+
+  <joint name="j_world" type="fixed">
+    <parent link="world"/>
+    <child link="base_link"/>
+    <origin xyz="0.0 0.0 0.07" rpy="0 0 0" />
+  </joint>
+
+  <link name="base_link">
+    <visual>
+      <origin xyz="0 0 0" rpy="0 0 0" />
+      <geometry>
+        <box size="0.05 0.05 0.1" /> 
+      </geometry>
+      <material name="Grey">
+        <color rgba="0.79 0.82 0.93 1.0"/>
+      </material>
+    </visual>
+    <inertial>
+      <mass value="0.975599" />
+      <origin xyz="0.00002469 -0.029448 -0.01576428" rpy="0 0 0"/>
+      <inertia ixx="0.00175853" ixy="-0.00000031" ixz="0.00000081" iyy="0.00187076" iyz="-0.00002473" izz="0.00246393" />
+    </inertial>
+    <collision>
+      <origin xyz="0 0 0" rpy="0 0 0" />
+      <geometry>
+        <box size="0.05 0.05 0.1" />
+      </geometry>
+    </collision>
+  </link>
+
+  <gazebo reference="base_link">
+    <material>Gazebo/Grey</material>
+  </gazebo>
+
+  <link name="internal_link">
+    <inertial>
+      <mass value="0.1" />
+      <origin xyz="0.0 0.0 0.0" rpy="0 0 0"/>
+      <inertia ixx="0.001" ixy="0.0" ixz="0.0" iyy="0.001" iyz="0.0" izz="0.001" />
+    </inertial>
+  </link>
+
+  <gazebo reference="internal_link">
+    <material>Gazebo/Grey</material>
+  </gazebo>
+
+  <joint name="j_roll" type="revolute">
+    <parent link="base_link"/>
+    <child link="internal_link"/>
+    <origin xyz="0.0 0.0 0.07" rpy="0 0 0" />
+    <axis xyz="1 0 0" />
+    <limit effort="25" velocity="6.0" lower="-0.3" upper="0.3" />
+    <dynamics damping="0.4"/>
+  </joint>
+
+  <transmission name="tran_roll">
+    <type>transmission_interface/SimpleTransmission</type>
+    <joint name="j_roll">
+      <hardwareInterface>hardware_interface/EffortJointInterface</hardwareInterface>
+    </joint>
+    <actuator name="roll_motor">
+      <hardwareInterface>hardware_interface/EffortJointInterface</hardwareInterface>
+      <mechanicalReduction>1</mechanicalReduction>
+    </actuator>
+  </transmission>
+
+  <gazebo reference="j_roll">
+    <implicitSpringDamper>true</implicitSpringDamper>
+    <stopCfm>0.0</stopCfm>
+    <stopErp>0.0</stopErp>
+  </gazebo>
+
+  <link name="platform_link">
+    <visual>
+      <origin xyz="0 0 0" rpy="0 0 0" />
+      <geometry>
+        <box size="0.3 0.3 0.01" />
+      </geometry>
+      <material name="Grey">
+        <color rgba="0.79 0.82 0.93 1.0"/>
+      </material>
+    </visual>
+    <inertial>
+      <mass value="0.975599" />
+      <origin xyz="0.00002469 -0.029448 -0.01576428" rpy="0 0 0"/>
+      <inertia ixx="0.00175853" ixy="-0.00000031" ixz="0.00000081" iyy="0.00187076" iyz="-0.00002473" izz="0.00246393" />
+    </inertial>
+    <collision>
+      <origin xyz="0 0 0" rpy="0 0 0" />
+      <geometry>
+        <box size="0.3 0.3 0.01" />
+      </geometry>
+    </collision>
+  </link>
+
+  <gazebo reference="platform_link">
+    <material>Gazebo/Grey</material>
+  </gazebo>
+
+  <joint name="j_pitch" type="revolute">
+    <parent link="internal_link"/>
+    <child link="platform_link"/>
+    <origin xyz="0 0 0" rpy="0 0 0" />
+    <axis xyz="0 1 0" />
+    <limit effort="25" velocity="6.0" lower="-0.3" upper="0.3" />
+    <dynamics damping="0.4"/>
+  </joint>
+
+  <transmission name="tran_pitch">
+    <type>transmission_interface/SimpleTransmission</type>
+    <joint name="j_pitch">
+      <hardwareInterface>hardware_interface/EffortJointInterface</hardwareInterface>
+    </joint>
+    <actuator name="pitxh_motor">
+      <hardwareInterface>hardware_interface/EffortJointInterface</hardwareInterface>
+      <mechanicalReduction>1</mechanicalReduction>
+    </actuator>
+  </transmission>
+
+  <gazebo reference="j_pitch">
+    <implicitSpringDamper>true</implicitSpringDamper>
+    <stopCfm>0.0</stopCfm>
+    <stopErp>0.0</stopErp>
+  </gazebo>
+
+  <gazebo>
+    <plugin name="gazebo_ros_control" filename="libgazebo_ros_control.so">
+      <robotNamespace>/platform</robotNamespace>
+    </plugin>
+  </gazebo>
+</robot>
+