在gazebo下仿真机器人并控制

第一次在gazebo里面跑自己的小车，很兴奋，在这里记录下。
urdf文件为dd_robot.urdf

<?xml version="1.0"?>
<robot name ="dd_robot">
    <!--Base link-->
    <link name="base_link">
        <visual>
            <origin xyz="0 0 0" rpy="0 0 0 "/>
            <geometry>
                <box size="0.4 0.5 0.25" />
            </geometry>
            <material name="yellow">
                <color rgba="1 0.4 0 1"/>
            </material>
        </visual>
        <!--base link collsion-->
        <collision>
            <origin xyz="0.0 0.0 0.0" rpy="0.0 0.0 0.0"/>
             <geometry>
                <box size="0.4 0.5 0.25" />
            </geometry>           
        </collision>
        <inertial>
            <mass value="5"/>
            <inertia ixx="0.13" ixy="0.0" ixz="0.0" 
                     iyy="0.21" iyz="0.0" izz="0.13"/>
        </inertial>
    </link>
    <gazebo reference="base_link">
        <material>Gazebo/Yellow</material>
    </gazebo>
    <!--joint_right_wheel-->
    <joint name="joint_right_wheel" type="continuous">
      <parent link="base_link"/>
      <child link="right_wheel"/>
    <origin xyz="-0.1 -0.30 0.0" rpy="1.570795 0 0"/>
    <axis xyz="0.0 0 1"/>

    </joint>
    
    <!--right link-->
    <link name="right_wheel">
        <visual>
            <origin xyz="0 0 0" rpy="0 0 0 "/>
            <geometry>
                <cylinder radius="0.2" length="0.1"/> 
            </geometry>
            <material name="red">
                <color rgba="1 0 0 1"/>
            </material>
        </visual>
        <collision>
            <origin xyz="0.0 0.0 0.0" rpy="0.0 0.0 0.0"/>
            <geometry>
                <cylinder radius="0.2" length="0.1"/> 
            </geometry>
        </collision>
         <inertial>
            <mass value="0.5"/>
            <inertia ixx="0.01" ixy="0.0" ixz="0.0" 
                     iyy="0.005" iyz="0.0" izz="0.005"/>
        </inertial>       
    </link>
    <gazebo reference="right_wheel">
        <material>Gazebo/Red</material>
    </gazebo>
    <!--joint_left_wheel-->
    <joint name="joint_left_wheel" type="continuous">
      <parent link="base_link"/>
      <child link="left_wheel"/>
    <origin xyz=" -0.10 0.3  0.0" rpy=" 1.570795 0 0"/>
    <axis xyz="0.0 0 1.0"/>
    </joint>
    
    <!--left link-->
    <link name="left_wheel">
        <visual>
            <origin xyz="0 0 0" rpy="0 0 0 "/>
            <geometry>
                <cylinder radius="0.2" length="0.1"/> 
            </geometry>
            <material name="red">
                <color rgba="1 0 0 1"/>
            </material>
        </visual>
        <collision>
            <origin xyz="0.0 0.0 0.0" rpy="0.0 0.0 0.0"/>
            <geometry>
                <cylinder radius="0.2" length="0.1"/> 
            </geometry>
        </collision>
          <inertial>
            <mass value="0.5"/>
            <inertia ixx="0.01" ixy="0.0" ixz="0.0" 
                     iyy="0.005" iyz="0.0" izz="0.005"/>
        </inertial>         
    </link>
    <gazebo reference="left_wheel">
        <material>Gazebo/Red</material>
    </gazebo>
        <!--front_castor_joint-->
    <joint name="front_castor_joint" type="fixed">
      <parent link="base_link"/>
      <child link="front_castor_link"/>
    <origin xyz=" 0.1625 0 -0.1625" rpy="0.0 0.0 0.0"/>
    <axis xyz="0.0 1 0.0"/>
    </joint>
        <!--front castor link-->
    <link name="front_castor_link">
        <visual>
            <origin xyz="0 0 0" rpy="0 0 0 "/>
            <geometry>
                <sphere radius="0.0375"/>
            </geometry>
            <material name="red">
                <color rgba="1 0 0 1"/>
            </material>
        </visual>

        <collision>
            <origin xyz="0.0 0.0 0.0" rpy="0.0 0.0 0.0"/>
             <geometry>
                <sphere radius="0.0375"/>
            </geometry>
        </collision>
        <inertial>
            <mass value="0.5"/>
            <inertia ixx="0.0001" ixy="0.0" ixz="0.0" iyy="0.0001" iyz="0.0" izz="0.0001"/>
        </inertial>
    </link>
    <gazebo reference="front_castor_link">
        <material>Gazebo/Red</material>
    </gazebo>

<link name="base_footprint">
            <visual>
                <origin xyz="0 0 0" rpy="0 0 0" />
                <geometry>
                    <box size="0.001 0.001 0.001" />
                </geometry>
            </visual>
        </link>

        <joint name="base_footprint_joint" type="fixed">
            <origin xyz="0 0 0.2" rpy="0 0 0" />
            <parent link="base_footprint"/>
            <child link="base_link" />
        </joint>

<!-- Transmission is important to link the joints and the controller -->
    <transmission name="joint_left_wheel_trans">
        <type>transmission_interface/SimpleTransmission</type>
        <joint name="joint_left_wheel" />
        <actuator name="joint_left_motor">
            <hardwareInterface>VelocityJointInterface</hardwareInterface>
            <mechanicalReduction>1</mechanicalReduction>
        </actuator>
    </transmission>

    <!-- Transmission is important to link the joints and the controller -->
    <transmission name="joint_right_wheel_trans">
        <type>transmission_interface/SimpleTransmission</type>
        <joint name="joint_right_wheel" />
        <actuator name="joint_right_motor">
            <hardwareInterface>VelocityJointInterface</hardwareInterface>
            <mechanicalReduction>1</mechanicalReduction>
        </actuator>
    </transmission>

    <!-- controller -->
    <gazebo>
        <plugin name="differential_drive_controller" filename="libgazebo_ros_diff_drive.so">
            <rosDebugLevel>Debug</rosDebugLevel>
            <publishWheelTF>true</publishWheelTF>
            <robotNamespace>/</robotNamespace>
            <publishTf>1</publishTf>
            <publishWheelJointState>true</publishWheelJointState>
            <publishOdomTF>true</publishOdomTF>
            <alwaysOn>true</alwaysOn>
            <updateRate>100.0</updateRate>
            <legacyMode>true</legacyMode>
            <leftJoint>joint_left_wheel</leftJoint>
            <rightJoint>joint_right_wheel</rightJoint>
            <wheelSeparation>${0.5*2}</wheelSeparation>
            <wheelDiameter>${2*0.2}</wheelDiameter>
            <broadcastTF>1</broadcastTF>
            <wheelTorque>30</wheelTorque>
            <wheelAcceleration>1.8</wheelAcceleration>
            <commandTopic>cmd_vel</commandTopic>
            <odometryFrame>odom</odometryFrame> 
            <odometryTopic>odom</odometryTopic> 
            <odometrySource>odom</odometrySource>
            <robotBaseFrame>base_footprint</robotBaseFrame>
        </plugin>
    </gazebo> 
</robot>

launch文件为dd_robot_gazebo.launch：

<launch>

    <!-- 设置launch文件的参数 -->
    <arg name="world_name" value="$(find ros_robotic)/worlds/playground.world"/>
    <arg name="paused" default="false"/>
    <arg name="use_sim_time" default="true"/>
    <arg name="gui" default="true"/>
    <arg name="headless" default="false"/>
    <arg name="debug" default="false"/>
    <arg name="model" default="$(find ros_robotic)/urdf/dd_robot.urdf"/>
    <!-- 运行gazebo仿真环境 -->
    <include file="$(find gazebo_ros)/launch/empty_world.launch">
        <arg name="debug" value="$(arg debug)" />
        <arg name="gui" value="$(arg gui)" />
        <arg name="paused" value="$(arg paused)"/>
        <arg name="use_sim_time" value="$(arg use_sim_time)"/>
        <arg name="headless" value="$(arg headless)"/>
    </include>
   <param name="robot_description" command="$(find xacro)/xacro --inorder $(arg model)" />

    <node name="joint_state_publisher" pkg="joint_state_publisher" type="joint_state_publisher" ></node> 

    <!-- 运行robot_state_publisher节点，发布tf  -->
    <node name="robot_state_publisher" pkg="robot_state_publisher" type="robot_state_publisher"  output="screen" >
        <param name="publish_frequency" type="double" value="50.0" />
    </node>

    <node name="urdf_spawner" pkg="gazebo_ros" type="spawn_model" args=" -urdf -model dd_robot -param robot_description" respawn="false" output="screen" /> 


    

</launch>

运行roslaunch ros_robotic dd_robot_gazebo.launch

整个catkin_ws/src目录如下：

src
    ├── arbotix_ros
    │   ├── arbotix
    │   │   ├── CHANGELOG.rst
    │   │   ├── CMakeLists.txt
    │   │   └── package.xml
    │   ├── arbotix_controllers
    │   │   ├── bin
    │   │   ├── CHANGELOG.rst
    │   │   ├── CMakeLists.txt
    │   │   └── package.xml
    │   ├── arbotix_firmware
    │   │   ├── CHANGELOG.rst
    │   │   ├── CMakeLists.txt
    │   │   ├── package.xml
    │   │   └── src
    │   ├── arbotix_msgs
    │   │   ├── CHANGELOG.rst
    │   │   ├── CMakeLists.txt
    │   │   ├── msg
    │   │   ├── package.xml
    │   │   └── srv
    │   ├── arbotix_python
    │   │   ├── bin
    │   │   ├── CHANGELOG.rst
    │   │   ├── CMakeLists.txt
    │   │   ├── demos
    │   │   ├── mainpage.dox
    │   │   ├── package.xml
    │   │   ├── setup.py
    │   │   └── src
    │   ├── arbotix_sensors
    │   │   ├── bin
    │   │   ├── CHANGELOG.rst
    │   │   ├── CMakeLists.txt
    │   │   ├── package.xml
    │   │   ├── setup.py
    │   │   └── src
    │   └── README.md
    ├── CMakeLists.txt -> /opt/ros/kinetic/share/catkin/cmake/toplevel.cmake
    ├── ros_robotic
    │   ├── CMakeLists.txt
    │   ├── config
    │   │   └── fake_robot_arbotix.yaml
    │   ├── launch
    │   │   ├── dd_gazebo.launch
    │   │   ├── dd_robot_with_arbotix.launch
    │   │   └── dd_rviz.launch
    │   ├── package.xml
    │   ├── urdf
    │   │   ├── dd_robot.gazebo
    │   │   ├── dd_robot.gv
    │   │   ├── dd_robot.pdf
    │   │   ├── dd_robot.urdf
    │   │   └── urdfbackup.urdf
    │   ├── urdf.rviz
    │   └── worlds
    ├── teleop_twist_joy
    │   ├── CHANGELOG.rst
    │   ├── CMakeLists.txt
    │   ├── config
    │   │   ├── atk3.config.yaml
    │   │   ├── beitong.config.yaml
    │   │   ├── ps3.config.yaml
    │   │   ├── ps3-holonomic.config.yaml
    │   │   ├── xbox.config.yaml
    │   │   └── xd3.config.yaml
    │   ├── include
    │   │   └── teleop_twist_joy
    │   ├── launch
    │   │   └── teleop.launch
    │   ├── LICENSE.txt
    │   ├── package.xml
    │   ├── README.md
    │   ├── src
    │   │   ├── teleop_node.cpp
    │   │   └── teleop_twist_joy.cpp
    │   └── test
    │       ├── differential_joy.test
    │       ├── holonomic_joy.test
    │       ├── no_enable_joy.test
    │       ├── only_turbo_joy.test
    │       ├── six_dof_joy.test
    │       ├── test_joy_twist.py
    │       ├── turbo_angular_enable_joy.test
    │       ├── turbo_angular_enable_joy_with_rosparam_map.test
    │       └── turbo_enable_joy.test
    └── teleop_twist_keyboard
        ├── CHANGELOG.rst
        ├── CMakeLists.txt
        ├── package.xml
        ├── README.md
        └── teleop_twist_keyboard.py

同样，可以游戏手柄控制，APP控制（只要在同一个wifi下）。
下一步来学习下xacro来简化下urdf。