Gazebo + ROS で自分だけのロボットをつくる 5. GazeboとROSの連携 ref: http://qiita.com/RyodoTanaka/items/6fa7e45f98b55376a95b

<your_robot_name>_control.launch

<launch>

  <!-- Load joint controller configurations from YAML file to parameter server -->
  <rosparam file="$(find fourth_robot_control)/config/controller.yaml" command="load"/>

  <!-- load the controllers -->
  <node name="controller_spawner" pkg="controller_manager"
                type="spawner" ns="fourth_robot" output="screen" 
                args="joint_state_controller
                          diff_drive_controller"/>

  <!-- convert joint states to TF transforms for rviz, etc -->
  <node name="robot_state_publisher" pkg="robot_state_publisher"
                type="robot_state_publisher"
                respawn="false" output="screen" ns="/fourth_robot">
  </node>

</launch>

controller.yaml

fourth_robot:
  joint_state_controller:
    type: joint_state_controller/JointStateController
    publish_rate: 50

  diff_drive_controller:
    type        : "diff_drive_controller/DiffDriveController"
    left_wheel  : 'left_wheel_joint'
    right_wheel : 'right_wheel_joint'
    publish_rate: 25.0               # default: 50
    pose_covariance_diagonal : [0.001, 0.001, 1000000.0, 1000000.0, 1000000.0, 1000.0]
    twist_covariance_diagonal: [0.001, 0.001, 1000000.0, 1000000.0, 1000000.0, 1000.0]

    # Wheel separation and diameter. These are both optional.
    # diff_drive_controller will attempt to read either one or both from the
    # URDF if not specified as a parameter
    wheel_separation : 0.43515
    wheel_radius : 0.032

    # Wheel separation and radius multipliers
    wheel_separation_multiplier: 1.0 # default: 1.0

file3.txt

<your_robot_name>_control
├── CMakeLists.txt
├── config
│   └── controller.yaml
├── launch
│   └── <your_robot_name>_control.launch
└── package.xml

fourth_robot_gazebo_element.urdf

  <gazebo>
    <plugin name="gazebo_ros_control" filename="libgazebo_ros_control.so">
      <robotNamespace>fourth_robot</robotNamespace>
    </plugin>
  </gazebo>

package.xml

<?xml version="1.0"?>
<package>
  <name><your_robot_name>_control</name>
  <version>1.0.0</version>
  <description>The <your_robot_name>_control package</description>

  <maintainer email="your@mail.com">YourName/maintainer>
  <license>BSD</license>

  <buildtool_depend>catkin</buildtool_depend>  
  <run_depend>controller_manager</run_depend>
  <run_depend>actionlib</run_depend>
  <run_depend>actionlib_msgs</run_depend>
  <run_depend>control_msgs</run_depend>
  <run_depend>sensor_msgs</run_depend>
  <run_depend>robot_state_publisher</run_depend>

</package>

wheel.gazebo.xacro

<?xml version="1.0"?>
<robot xmlns:xacro="http://ros.org/wiki/xacro">

  <xacro:macro name="wheel_gazebo_v0" params="prefix">
    <gazebo reference="${prefix}_wheel_link">
      <selfCollide>true</selfCollide>
      <mu1 value="0.8" />
      <mu2 value="0.8" />
    </gazebo>
  </xacro:macro>
</robot>

wheel.transmission.xacro

<?xml version="1.0"?>
<robot xmlns:xacro="http://ros.org/wiki/xacro">

  <xacro:macro name="wheel_trans_v0" params="prefix">
    <transmission name="${prefix}_wheel_trans">
      <type>transmission_interface/SimpleTransmission</type>
      <joint name="${prefix}_wheel_joint">
        <hardwareInterface>VelocityJointInterface</hardwareInterface>
      </joint>
      <actuator name="${prefix}_wheel_motor">
        <hardwareInterface>VelocityJointInterface</hardwareInterface>
        <mechanicalReduction>30</mechanicalReduction>
      </actuator>
    </transmission>
  </xacro:macro> 

</robot>