之前的博客中，我们使用rviz进行了TurtleBot的仿真，而且使用urdf文件建立了自己的机器人smartcar，本篇博客是将两者进行结合，使用smartcar机器人在rviz中进行仿真。

一、模型完善

        之前我们使用的都是urdf文件格式的模型，在很多情况下，ROS对urdf文件的支持并不是很好，使用宏定义的.xacro文件兼容性更好，扩展性也更好。所以我们把之前的urdf文件重新整理编写成.xacro文件。 .xacro文件主要分为三部分：

1、机器人主体

  
<?xml version="1.0"?>  
<robot name="smartcar" xmlns:xacro="http://ros.org/wiki/xacro">  
  <property name="M_PI" value="3.14159"/>  
  
  <!-- Macro for SmartCar body. Including Gazebo extensions, but does not include Kinect -->  
  <include filename="$(find smartcar_description)/urdf/gazebo.urdf.xacro"/>  
  
  <property name="base_x" value="0.33" />  
  <property name="base_y" value="0.33" />  
  
  <xacro:macro name="smartcar_body">  
  
  
    <link name="base_link">  
    <inertial>  
      <origin xyz="0 0 0.055"/>  
      <mass value="1.0" />  
      <inertia ixx="1.0" ixy="0.0" ixz="0.0" iyy="1.0" iyz="0.0" izz="1.0"/>  
    </inertial>  
    <visual>  
      <geometry>  
        <box size="0.25 .16 .05"/>  
      </geometry>  
      <origin rpy="0 0 0" xyz="0 0 0.055"/>  
      <material name="blue">  
      <color rgba="0 0 .8 1"/>  
      </material>  
   </visual>  
   <collision>  
      <origin rpy="0 0 0" xyz="0 0 0.055"/>  
      <geometry>  
        <box size="0.25 .16 .05" />  
      </geometry>  
    </collision>  
  </link>  
  
  
 <link name="left_front_wheel">  
    <inertial>  
      <origin  xyz="0.08 0.08 0.025"/>  
      <mass value="0.1" />  
       <inertia ixx="1.0" ixy="0.0" ixz="0.0" iyy="1.0" iyz="0.0" izz="1.0"/>  
    </inertial>  
    <visual>  
      <geometry>  
        <cylinder length=".02" radius="0.025"/>  
      </geometry>  
      <material name="black">  
        <color rgba="0 0 0 1"/>  
      </material>  
    </visual>  
    <collision>  
      <origin rpy="0 1.57075 1.57075" xyz="0.08 0.08 0.025"/>  
      <geometry>  
         <cylinder length=".02" radius="0.025"/>  
      </geometry>  
    </collision>  
  </link>  
  
  <joint name="left_front_wheel_joint" type="continuous">  
    <axis xyz="0 0 1"/>  
    <parent link="base_link"/>  
    <child link="left_front_wheel"/>  
    <origin rpy="0 1.57075 1.57075" xyz="0.08 0.08 0.025"/>  
    <limit effort="100" velocity="100"/>  
    <joint_properties damping="0.0" friction="0.0"/>  
  </joint>  
  
  <link name="right_front_wheel">  
    <inertial>  
      <origin xyz="0.08 -0.08 0.025"/>  
      <mass value="0.1" />  
       <inertia ixx="1.0" ixy="0.0" ixz="0.0" iyy="1.0" iyz="0.0" izz="1.0"/>  
    </inertial>  
    <visual>  
      <geometry>  
        <cylinder length=".02" radius="0.025"/>  
      </geometry>  
      <material name="black">  
        <color rgba="0 0 0 1"/>  
      </material>  
    </visual>  
    <collision>  
      <origin rpy="0 1.57075 1.57075" xyz="0.08 -0.08 0.025"/>  
      <geometry>  
         <cylinder length=".02" radius="0.025"/>  
      </geometry>  
    </collision>  
  </link>  
  
  <joint name="right_front_wheel_joint" type="continuous">  
    <axis xyz="0 0 1"/>  
    <parent link="base_link"/>  
    <child link="right_front_wheel"/>  
    <origin rpy="0 1.57075 1.57075" xyz="0.08 -0.08 0.025"/>  
    <limit effort="100" velocity="100"/>  
    <joint_properties damping="0.0" friction="0.0"/>  
 </joint>  
  
 <link name="left_back_wheel">  
    <inertial>  
      <origin xyz="-0.08 0.08 0.025"/>  
      <mass value="0.1" />  
       <inertia ixx="1.0" ixy="0.0" ixz="0.0" iyy="1.0" iyz="0.0" izz="1.0"/>  
    </inertial>  
    <visual>  
      <geometry>  
        <cylinder length=".02" radius="0.025"/>  
      </geometry>  
      <material name="black">  
        <color rgba="0 0 0 1"/>  
      </material>  
   </visual>  
   <collision>  
       <origin rpy="0 1.57075 1.57075" xyz="-0.08 0.08 0.025"/>  
      <geometry>  
         <cylinder length=".02" radius="0.025"/>  
      </geometry>  
    </collision>  
  </link>  
  
  <joint name="left_back_wheel_joint" type="continuous">  
    <axis xyz="0 0 1"/>  
    <parent link="base_link"/>  
    <child link="left_back_wheel"/>  
    <origin rpy="0 1.57075 1.57075" xyz="-0.08 0.08 0.025"/>  
    <limit effort="100" velocity="100"/>  
    <joint_properties damping="0.0" friction="0.0"/>  
  </joint>  
  
  <link name="right_back_wheel">  
    <inertial>  
       <origin xyz="-0.08 -0.08 0.025"/>  
       <mass value="0.1" />  
       <inertia ixx="1.0" ixy="0.0" ixz="0.0" iyy="1.0" iyz="0.0" izz="1.0"/>  
    </inertial>  
    <visual>  
      <geometry>  
        <cylinder length=".02" radius="0.025"/>  
      </geometry>  
      <material name="black">  
        <color rgba="0 0 0 1"/>  
      </material>  
   </visual>  
   <collision>  
      <origin rpy="0 1.57075 1.57075" xyz="-0.08 -0.08 0.025"/>  
      <geometry>  
         <cylinder length=".02" radius="0.025"/>  
      </geometry>  
    </collision>  
  </link>  
  
  
  <joint name="right_back_wheel_joint" type="continuous">  
    <axis xyz="0 0 1"/>  
    <parent link="base_link"/>  
    <child link="right_back_wheel"/>  
    <origin rpy="0 1.57075 1.57075" xyz="-0.08 -0.08 0.025"/>  
    <limit effort="100" velocity="100"/>  
    <joint_properties damping="0.0" friction="0.0"/>  
  </joint>  
  
  <link name="head">  
    <inertial>  
      <origin xyz="0.08 0 0.08"/>  
      <mass value="0.1" />  
      <inertia ixx="1.0" ixy="0.0" ixz="0.0" iyy="1.0" iyz="0.0" izz="1.0"/>  
    </inertial>  
    <visual>  
      <geometry>  
        <box size=".02 .03 .03"/>  
      </geometry>  
      <material name="white">  
        <color rgba="1 1 1 1"/>  
      </material>  
     </visual>  
     <collision>  
      <origin xyz="0.08 0 0.08"/>  
      <geometry>  
         <cylinder length=".02" radius="0.025"/>  
      </geometry>  
    </collision>  
  </link>  
  
  <joint name="tobox" type="fixed">  
    <parent link="base_link"/>  
    <child link="head"/>  
    <origin xyz="0.08 0 0.08"/>  
  </joint>  
  </xacro:macro>  
  
</robot>
 

2、gazebo属性部分

<?xml version="1.0"?>  
  
<robot xmlns:controller="http://playerstage.sourceforge.net/gazebo/xmlschema/#controller"   
    xmlns:interface="http://playerstage.sourceforge.net/gazebo/xmlschema/#interface"   
    xmlns:sensor="http://playerstage.sourceforge.net/gazebo/xmlschema/#sensor"   
    xmlns:xacro="http://ros.org/wiki/xacro"   
    name="smartcar_gazebo">  
  
<!-- ASUS Xtion PRO camera for simulation -->  
<!-- gazebo_ros_wge100 plugin is in kt2_gazebo_plugins package -->  
<xacro:macro name="smartcar_sim">  
    <gazebo reference="base_link">  
        <material>Gazebo/Blue</material>  
    </gazebo>  
  
    <gazebo reference="right_front_wheel">  
        <material>Gazebo/FlatBlack</material>  
    </gazebo>  
  
    <gazebo reference="right_back_wheel">  
        <material>Gazebo/FlatBlack</material>  
    </gazebo>  
  
    <gazebo reference="left_front_wheel">  
        <material>Gazebo/FlatBlack</material>  
    </gazebo>  
  
    <gazebo reference="left_back_wheel">  
        <material>Gazebo/FlatBlack</material>  
    </gazebo>  
  
    <gazebo reference="head">  
        <material>Gazebo/White</material>  
    </gazebo>  
  
</xacro:macro>  
  
</robot>
 

3、主文件

<xml version="1.0"?>  
  
<robot name="smartcar"    
    xmlns:xi="http://www.w3.org/2001/XInclude"  
    xmlns:gazebo="http://playerstage.sourceforge.net/gazebo/xmlschema/#gz"  
    xmlns:model="http://playerstage.sourceforge.net/gazebo/xmlschema/#model"  
    xmlns:sensor="http://playerstage.sourceforge.net/gazebo/xmlschema/#sensor"  
    xmlns:body="http://playerstage.sourceforge.net/gazebo/xmlschema/#body"  
    xmlns:geom="http://playerstage.sourceforge.net/gazebo/xmlschema/#geom"  
    xmlns:joint="http://playerstage.sourceforge.net/gazebo/xmlschema/#joint"  
    xmlns:controller="http://playerstage.sourceforge.net/gazebo/xmlschema/#controller"  
    xmlns:interface="http://playerstage.sourceforge.net/gazebo/xmlschema/#interface"  
    xmlns:rendering="http://playerstage.sourceforge.net/gazebo/xmlschema/#rendering"  
    xmlns:renderable="http://playerstage.sourceforge.net/gazebo/xmlschema/#renderable"  
    xmlns:physics="http://playerstage.sourceforge.net/gazebo/xmlschema/#physics"  
    xmlns:xacro="http://ros.org/wiki/xacro">  
  
  <include filename="$(find smartcar_description)/urdf/smartcar_body.urdf.xacro" />  
  
  <!-- Body of SmartCar, with plates, standoffs and Create (including sim sensors) -->  
  <smartcar_body/>  
  
  <smartcar_sim/>  
  
</robot>
 

二、lanuch文件

        在launch文件中要启动节点和模拟器。
<launch>  
    <param name="/use_sim_time" value="false" />  
      
    <!-- Load the URDF/Xacro model of our robot -->  
    <arg name="urdf_file" default="$(find xacro)/xacro.py '$(find smartcar_description)/urdf/smartcar.urdf.xacro'" />  
    <arg name="gui" default="false" />  
  
    <param name="robot_description" command="$(arg urdf_file)" />  
    <param name="use_gui" value="$(arg gui)"/>  
  
    <node name="arbotix" pkg="arbotix_python" type="driver.py" output="screen">  
        <rosparam file="$(find smartcar_description)/config/smartcar_arbotix.yaml" command="load" />  
        <param name="sim" value="true"/>  
    </node>  
  
    <node name="joint_state_publisher" pkg="joint_state_publisher" type="joint_state_publisher" >  
    </node>  
  
    <node name="robot_state_publisher" pkg="robot_state_publisher" type="state_publisher">  
        <param name="publish_frequency" type="double" value="20.0" />  
    </node>  
  
     <!-- We need a static transforms for the wheels -->  
    <node pkg="tf" type="static_transform_publisher" name="odom_left_wheel_broadcaster" args="0 0 0 0 0 0 /base_link /left_front_link 100" />  
    <node pkg="tf" type="static_transform_publisher" name="odom_right_wheel_broadcaster" args="0 0 0 0 0 0 /base_link /right_front_link 100" />  
  
    <node name="rviz" pkg="rviz" type="rviz" args="-d $(find smartcar_description)/urdf.vcg" />  
</launch>
 

三、仿真测试

        首先运行lanuch，既可以看到rviz中的机器人：

 

roslaunch smartcar_description smartcar_display.rviz.launch
 
         发布一条动作的消息。
rostopic pub -r 10 /cmd_vel geometry_msgs/Twist '{linear: {x: 0.5, y: 0, z: 0}, angular: {x: 0, y: 0, z: 0.5}}'
 

四、节点关系

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