ROS仿真一个可动小车时，单独在RVIZ里查看小车模型参数没有问题，但是在gazebo中驱动小车时，终端报错且RVIZ中小车模型出现错误

38088007

操作系统：ubantu18.04
ROS版本：melodic
gazebo9

新手小白在做一个可动小车的仿真时，遇到了如下问题，恳请各位相助！

我在RVIZ里查看小车模型时可以得到下图所示的模型图

小车模型图.png

但是当我输入命令

roslaunch steer_mini_gazebo steer_mini_sim.launch

在gazebo中驱动小车时，却出现了如下报错


[ INFO] [1701960022.508446103, 61.242000000]: gazebo_ros_control plugin is waiting for model URDF in parameter [robot_description] on the ROS param server.
[FATAL] [1701960022.609885892, 61.242000000]: Failed to create robot simulation interface loader: Could not find library corresponding to plugin steer_bot_hardware_gazebo/SteerBotHardwareGazebo. Make sure the plugin description XML file has the correct name of the library and that the library actually exists.
[ INFO] [1701960022.610109458, 61.242000000]: Loaded gazebo_ros_control.

且在RIVIZ中车轮的link也无法识别，如下图所示

在网上找了很久都没找到解决方案，恳请各位大佬帮忙！万分感谢！

相关代码附在下面：

小车的urdf文件

<?xml version="1.0" encoding="utf-8"?>
<!-- This URDF was automatically created by SolidWorks to URDF Exporter! Originally created by Stephen Brawner (brawner@gmail.com) 
     Commit Version: 1.5.1-0-g916b5db  Build Version: 1.5.7152.31018
     For more information, please see http://wiki.ros.org/sw_urdf_exporter -->
<robot
  name="neor_mini">
  
      <link name="base_link">
    <!-- avoid root link inertia warnings, annotation -->
      <!--
    <inertial>
      <origin
        xyz="0.030649671440691 -1.79069899872708E-05 0.0558717976709459"
        rpy="0 0 0" />
      <mass
        value="1.72617713171385" />
      <inertia
        ixx="0.0107311274569357"
        ixy="-3.24164649120244E-08"
        ixz="0.00169188715816868"
        iyy="0.0198871551919603"
        iyz="2.40252669081509E-07"
        izz="0.0269841937242323" />
    </inertial>
-->
    <visual>
      <origin xyz="0 0 0" rpy="0 0 0" />
      <geometry>
        <mesh filename="package://neor_mini/meshes/base_link.dae" />
      </geometry>
      <material name="">
      <color rgba="0.250980392156863 0.250980392156863 0.250980392156863 1" /> 
      </material> 
    </visual>
    <collision>
      <origin
        xyz="0 0 0"
        rpy="0 0 0" />
      <geometry>
        <mesh
          filename="package://neor_mini/meshes/base_link.STL" />
      </geometry>
    </collision>
  </link>
  <link
    name="rear_wheel_link">
    <inertial>
      <origin
        xyz="-8.88178419700125E-16 -2.05391259555654E-14 -0.00112500000001892"
        rpy="0 0 0" />
      <mass
        value="5.65486677646169E-05" />
      <inertia
        ixx="1.32005796313028E-10"
        ixy="-1.938704560671E-27"
        ixz="2.13770572261755E-26"
        iyy="1.32005796313028E-10"
        iyz="-7.60216295195271E-25"
        izz="2.03575203952622E-10" />
    </inertial>
    <visual>
      <origin
        xyz="0 0 0"
        rpy="0 0 0" />
      <geometry>
        <mesh
          filename="package://neor_mini/meshes/rear_wheel_link.STL" />
      </geometry>
      <material
        name="">
        <color
          rgba="0.274509803921569 1 0.247058823529412 1" />
      </material>
    </visual>
    <collision>
      <origin
        xyz="0 0 0"
        rpy="0 0 0" />
      <geometry>
        <mesh
          filename="package://neor_mini/meshes/rear_wheel_link.STL" />
      </geometry>
    </collision>
  </link>
  <joint
    name="rear_wheel_joint"
    type="continuous">
    <origin
      xyz="-0.181499999999597 0 0.0399999999987674"
      rpy="0 0 0" />
    <parent
      link="base_link" />
    <child
      link="rear_wheel_link" />
    <axis
      xyz="0 1 0" />
  </joint>
  <link
    name="left_rear_link">
    <inertial>
      <origin
        xyz="7.85229659072684E-11 -0.0196762547002777 4.85059770127805E-11"
        rpy="0 0 0" />
      <mass
        value="0.29556182905038" />
      <inertia
        ixx="0.000374087423652291"
        ixy="2.19336154342606E-13"
        ixz="-5.50404301757561E-12"
        iyy="0.000661017199375587"
        iyz="-5.10049385981967E-14"
        izz="0.000374087441459994" />
    </inertial>
    <visual>
      <origin
        xyz="0 0 0"
        rpy="0 0 0" />
      <geometry>
        <mesh
          filename="package://neor_mini/meshes/left_rear_link.STL" />
      </geometry>
      <material
        name="">
        <color
          rgba="0.792156862745098 0.819607843137255 0.933333333333333 1" />
      </material>
    </visual>
    <collision>
      <origin
        xyz="0 0 0"
        rpy="0 0 0" />
      <geometry>
        <mesh
          filename="package://neor_mini/meshes/left_rear_link.STL" />
      </geometry>
    </collision>
  </link>
  <joint
    name="left_rear_joint"
    type="continuous">
    <origin
      xyz="-0.181499999999595 0.228542434993694 0.0399999999991634"
      rpy="0 0 0" />
    <parent
      link="base_link" />
    <child
      link="left_rear_link" />
    <axis
      xyz="0 1 0" />
    <limit
      lower="-3.14"
      upper="3.14"
      effort="0"
      velocity="0" />
  </joint>
  <link
    name="right_rear_link">
    <inertial>
      <origin
        xyz="7.8521189550429E-11 0.0196762545376323 3.35983463273237E-11"
        rpy="0 0 0" />
      <mass
        value="0.295561829050389" />
      <inertia
        ixx="0.000374087423652306"
        ixy="-2.1933774523493E-13"
        ixz="5.50404145624456E-12"
        iyy="0.000661017199375601"
        iyz="-5.10073974604221E-14"
        izz="0.000374087441459995" />
    </inertial>
    <visual>
      <origin
        xyz="0 0 0"
        rpy="0 0 0" />
      <geometry>
        <mesh
          filename="package://neor_mini/meshes/right_rear_link.STL" />
      </geometry>
      <material
        name="">
        <color
          rgba="0.792156862745098 0.819607843137255 0.933333333333333 1" />
      </material>
    </visual>
    <collision>
      <origin
        xyz="0 0 0"
        rpy="0 0 0" />
      <geometry>
        <mesh
          filename="package://neor_mini/meshes/right_rear_link.STL" />
      </geometry>
    </collision>
  </link>
  <joint
    name="right_rear_joint"
    type="continuous">
    <origin
      xyz="-0.181499999999595 -0.228542434994426 0.0399999999991584"
      rpy="0 0 0" />
    <parent
      link="base_link" />
    <child
      link="right_rear_link" />
    <axis
      xyz="0 1 0" />
    <limit
      lower="-3.14"
      upper="3.14"
      effort="0"
      velocity="0" />
  </joint>
  <link
    name="front_steer_link">
    <inertial>
      <origin
        xyz="-2.1316282072803E-14 3.67778030252452E-11 -0.00112486602459905"
        rpy="0 0 0" />
      <mass
        value="5.65486677646163E-05" />
      <inertia
        ixx="1.32005796313026E-10"
        ixy="1.16322273640277E-26"
        ixz="1.20446157864484E-28"
        iyy="1.32005796313026E-10"
        iyz="-8.66481261175625E-27"
        izz="2.03575203952619E-10" />
    </inertial>
    <visual>
      <origin
        xyz="0 0 0"
        rpy="0 0 0" />
      <geometry>
        <mesh
          filename="package://neor_mini/meshes/front_steer_link.STL" />
      </geometry>
      <material
        name="">
        <color
          rgba="0.274509803921569 1 0.247058823529412 1" />
      </material>
    </visual>
    <collision>
      <origin
        xyz="0 0 0"
        rpy="0 0 0" />
      <geometry>
        <mesh
          filename="package://neor_mini/meshes/front_steer_link.STL" />
      </geometry>
    </collision>
  </link>
  <joint
    name="front_steer_joint"
    type="revolute">
    <origin
      xyz="0.172883370897628 0 -0.00376561854722868"
      rpy="0 0 0" />
    <parent
      link="base_link" />
    <child
      link="front_steer_link" />
    <axis
      xyz="0 0 1" />
    <limit
      lower="-0.72"
      upper="0.72"
      effort="0"
      velocity="0" />
  </joint>

<!-- In order to fit ackermann simulation plugins's request,amend the front steer link and it's joint -->
 <link name="front_steer_right_link">
 <!--  remember add inertial  label,if not,and it can't visual on gazebo-->
 <inertial>  
      <origin xyz="9.44636555644252E-08 -0.000295273745285485 -8.13046296954667E-11" rpy="0 0 0" />
      <mass value="0.296315811300368" /> 
      <inertia
        ixx="0.000374692013709393"
        ixy="-9.17172260383823E-08"
        ixz="-2.43187512356516E-12"
        iyy="0.000661029987747155"
        iyz="1.9736939507106E-13"
        izz="0.000374691963930348" />
    </inertial>
   <visual>
     <geometry>
       <cylinder length="0.001" radius="0.005"/>
     </geometry>
     <origin rpy="0 0 0"  xyz="0 0 0" />
     <material name=""> 
          <color rgba="0.792156862745098 0.819607843137255 0.933333333333333 1" />
     </material>
   </visual>
   <collision>
      <origin
        xyz="0 0 0"
        rpy="0 0 0" />
      <geometry>
       <cylinder length="0.001" radius="0.005"/>
      </geometry>
    </collision>
 </link>
 <joint name="front_steer_right_joint" type="revolute">
    <origin rpy="0 0 0"  xyz="0.17 -0.21 0.102" />
    <parent link="base_link" />
    <child link="front_steer_right_link" />
    <axis xyz="0 0 1" />     <!-- charge steer direction default is 0 0 1-->
    <limit lower="-0.69" upper="0.69" effort="0" velocity="0" />
 </joint>
<!-- ************************************************************************************* -->

  <link
    name="front_right_wheel_link">
    <inertial>
      <origin
        xyz="9.44636555644252E-08 -0.000295273745285485 -8.13046296954667E-11"
        rpy="0 0 0" />
      <mass
        value="0.296315811300368" />
      <inertia
        ixx="0.000374692013709393"
        ixy="-9.17172260383823E-08"
        ixz="-2.43187512356516E-12"
        iyy="0.000661029987747155"
        iyz="1.9736939507106E-13"
        izz="0.000374691963930348" />
    </inertial>
    <visual>
      <origin
        xyz="0 0 0"
        rpy="0 0 0" />
      <geometry>
        <mesh
          filename="package://neor_mini/meshes/front_right_wheel_link.STL" />
      </geometry>
      <material
        name="">
        <color
          rgba="0.792156862745098 0.819607843137255 0.933333333333333 1" />
      </material>
    </visual>
    <collision>
      <origin
        xyz="0 0 0"
        rpy="0 0 0" />
      <geometry>
        <mesh
          filename="package://neor_mini/meshes/front_right_wheel_link.STL" />
      </geometry>
    </collision>
  </link>
  <joint name="front_right_wheel_joint" type="continuous">
    <origin xyz="0 0 -0.06" rpy="0 0 0" />   <!-- amend the position between steer_right_link and front right wheel-->
    <parent link="front_steer_right_link" />
    <child  link="front_right_wheel_link" />
    <axis xyz="0 1 0" />
  </joint>

<!-- In order to fit ackermann simulation plugins's request,amend the front steer link and it's joint -->
 <link name="front_steer_left_link">
 <!--  remember add inertial  label,if not,and it can't visual on gazebo-->
    <inertial> 
      <origin xyz="9.44636555644252E-08 -0.000295273745285485 -8.13046296954667E-11" rpy="0 0 0" />
      <mass value="0.296315811300368" /> 
      <inertia
        ixx="0.000374692013709393"
        ixy="-9.17172260383823E-08"
        ixz="-2.43187512356516E-12"
        iyy="0.000661029987747155"
        iyz="1.9736939507106E-13"
        izz="0.000374691963930348" />
    </inertial>
   <visual>
     <geometry>
       <cylinder length="0.001" radius="0.005"/>
     </geometry>
     <origin rpy="0 0 0"  xyz="0 0 0" />
   </visual>
    <collision>
      <origin xyz="0 0 0" rpy="0 0 0" />
      <geometry>
       <cylinder length="0.001" radius="0.005"/>
      </geometry>
    </collision>
 </link>
 <joint name="front_steer_left_joint" type="revolute">
    <origin rpy="0 0 0"  xyz="0.17 0.21 0.102" />
    <parent link="base_link" />
    <child link="front_steer_left_link" />
    <axis xyz="0 0 1" />  <!-- charge steer direction default is 0 0 1-->
    <limit lower="-0.69" upper="0.69" effort="0" velocity="0" />
 </joint>
<!-- ************************************************************************************* -->

  <link
    name="front_left_wheel_link">
    <inertial>
      <origin
        xyz="-3.99413835339146E-11 0.000295273997845347 1.08602016268833E-10"
        rpy="0 0 0" />
      <mass
        value="0.296315811293944" />
      <inertia
        ixx="0.00037469197851121"
        ixy="-1.84493877596723E-13"
        ixz="-9.50756757097929E-12"
        iyy="0.00066103001709398"
        iyz="-1.17866882205563E-13"
        izz="0.000374691969713977" />
    </inertial>
    <visual>
      <origin
        xyz="0 0 0"
        rpy="0 0 0" />
      <geometry>
        <mesh
          filename="package://neor_mini/meshes/front_left_wheel_link.STL" />
      </geometry>
      <material
        name="">
        <color
          rgba="0.792156862745098 0.819607843137255 0.933333333333333 1" />
      </material>
    </visual>
    <collision>
      <origin
        xyz="0 0 0"
        rpy="0 0 0" />
      <geometry>
        <mesh
          filename="package://neor_mini/meshes/front_left_wheel_link.STL" />
      </geometry>
    </collision>
  </link>
  <joint name="front_left_wheel_joint" type="continuous">
    <origin xyz="0 0 -0.06" rpy="0 0 0" />      <!-- amend the position between steer_left_link and front left wheel-->
    <parent link="front_steer_left_link" />
    <child link="front_left_wheel_link" />
    <axis xyz="0 1 0" /> 
  </joint>

</robot>

在gazebo中驱动小车的urdf文件

<?xml version="1.0" encoding="utf-8"?>
<!-- This URDF was automatically created by SolidWorks to URDF Exporter! Originally created by Stephen Brawner (brawner@gmail.com) 
     Commit Version: 1.5.1-0-g916b5db  Build Version: 1.5.7152.31018
     For more information, please see http://wiki.ros.org/sw_urdf_exporter -->
<robot name="neor_mini">

  <!-- Add Gazebo plugins -->
    <!-- Load ros_control plugin using the steer_bot_hardware_gazebo
    implementation of the hardware_interface::RobotHW -->

  <gazebo>
    <plugin name="gazebo_ros_control" filename="libgazebo_ros_control.so">
      <robotSimType>steer_bot_hardware_gazebo/SteerBotHardwareGazebo</robotSimType>
      <legacyModeNS>false</legacyModeNS>
    </plugin>
  </gazebo>

       <link name="base_link">
    <!-- avoid root link inertia warnings, annotation -->
    <inertial>
      <origin
        xyz="0.030649671440691 -1.79069899872708E-05 0.0558717976709459"
        rpy="0 0 0" />
      <mass
        value="1.72617713171385" />
      <inertia
        ixx="0.0107311274569357"
        ixy="-3.24164649120244E-08"
        ixz="0.00169188715816868"
        iyy="0.0198871551919603"
        iyz="2.40252669081509E-07"
        izz="0.0269841937242323" />
    </inertial>

    <visual>
      <origin xyz="0 0 0" rpy="0 0 0" />
      <geometry>
        <mesh filename="package://neor_mini/meshes/base_link.dae" />
      </geometry>
      <material name="">
      <color rgba="0.250980392156863 0.250980392156863 0.250980392156863 1" /> 
      </material> 
    </visual>
    <collision>
      <origin
        xyz="0 0 0"
        rpy="0 0 0" />
      <geometry>
        <mesh
          filename="package://neor_mini/meshes/base_link.STL" />
      </geometry>
    </collision>
  </link>
  <link
    name="rear_wheel_link">
    <inertial>
      <origin
        xyz="-8.88178419700125E-16 -2.05391259555654E-14 -0.00112500000001892"
        rpy="0 0 0" />
      <mass
        value="5.65486677646169E-05" />
      <inertia
        ixx="1.32005796313028E-10"
        ixy="-1.938704560671E-27"
        ixz="2.13770572261755E-26"
        iyy="1.32005796313028E-10"
        iyz="-7.60216295195271E-25"
        izz="2.03575203952622E-10" />
    </inertial>
    <visual>
      <origin
        xyz="0 0 0"
        rpy="0 0 0" />
      <geometry>
        <mesh
          filename="package://neor_mini/meshes/rear_wheel_link.STL" />
      </geometry>
      <material
        name="">
        <color
          rgba="0.274509803921569 1 0.247058823529412 1" />
      </material>
    </visual>
    <collision>
      <origin
        xyz="0 0 0"
        rpy="0 0 0" />
      <geometry>
        <mesh
          filename="package://neor_mini/meshes/rear_wheel_link.STL" />
      </geometry>
    </collision>
  </link>
  <joint
    name="rear_wheel_joint"
    type="continuous">
    <origin
      xyz="-0.181499999999597 0 0.0399999999987674"
      rpy="0 0 0" />
    <parent
      link="base_link" />
    <child
      link="rear_wheel_link" />
    <axis
      xyz="0 1 0" />
  </joint>
  <link
    name="left_rear_link">
    <inertial>
      <origin
        xyz="7.85229659072684E-11 -0.0196762547002777 4.85059770127805E-11"
        rpy="0 0 0" />
      <mass
        value="0.29556182905038" />
      <inertia
        ixx="0.000374087423652291"
        ixy="2.19336154342606E-13"
        ixz="-5.50404301757561E-12"
        iyy="0.000661017199375587"
        iyz="-5.10049385981967E-14"
        izz="0.000374087441459994" />
    </inertial>
    <visual>
      <origin
        xyz="0 0 0"
        rpy="0 0 0" />
      <geometry>
        <mesh
          filename="package://neor_mini/meshes/left_rear_link.STL" />
      </geometry>
      <material
        name="">
        <color
          rgba="0.792156862745098 0.819607843137255 0.933333333333333 1" />
      </material>
    </visual>
    <collision>
      <origin
        xyz="0 0 0"
        rpy="0 0 0" />
      <geometry>
        <mesh
          filename="package://neor_mini/meshes/left_rear_link.STL" />
      </geometry>
    </collision>
  </link>
  <joint
    name="left_rear_joint"
    type="continuous">
    <origin
      xyz="-0.181499999999595 0.228542434993694 0.0399999999991634"
      rpy="0 0 0" />
    <parent
      link="base_link" />
    <child
      link="left_rear_link" />
    <axis
      xyz="0 1 0" />
    <limit
      lower="-3.14"
      upper="3.14"
      effort="0"
      velocity="0" />
  </joint>
  <link
    name="right_rear_link">
    <inertial>
      <origin
        xyz="7.8521189550429E-11 0.0196762545376323 3.35983463273237E-11"
        rpy="0 0 0" />
      <mass
        value="0.295561829050389" />
      <inertia
        ixx="0.000374087423652306"
        ixy="-2.1933774523493E-13"
        ixz="5.50404145624456E-12"
        iyy="0.000661017199375601"
        iyz="-5.10073974604221E-14"
        izz="0.000374087441459995" />
    </inertial>
    <visual>
      <origin
        xyz="0 0 0"
        rpy="0 0 0" />
      <geometry>
        <mesh
          filename="package://neor_mini/meshes/right_rear_link.STL" />
      </geometry>
      <material
        name="">
        <color
          rgba="0.792156862745098 0.819607843137255 0.933333333333333 1" />
      </material>
    </visual>
    <collision>
      <origin
        xyz="0 0 0"
        rpy="0 0 0" />
      <geometry>
        <mesh
          filename="package://neor_mini/meshes/right_rear_link.STL" />
      </geometry>
    </collision>
  </link>
  <joint
    name="right_rear_joint"
    type="continuous">
    <origin
      xyz="-0.181499999999595 -0.228542434994426 0.0399999999991584"
      rpy="0 0 0" />
    <parent
      link="base_link" />
    <child
      link="right_rear_link" />
    <axis
      xyz="0 1 0" />
    <limit
      lower="-3.14"
      upper="3.14"
      effort="0"
      velocity="0" />
  </joint>
  <link
    name="front_steer_link">
    <inertial>
      <origin
        xyz="-2.1316282072803E-14 3.67778030252452E-11 -0.00112486602459905"
        rpy="0 0 0" />
      <mass
        value="5.65486677646163E-05" />
      <inertia
        ixx="1.32005796313026E-10"
        ixy="1.16322273640277E-26"
        ixz="1.20446157864484E-28"
        iyy="1.32005796313026E-10"
        iyz="-8.66481261175625E-27"
        izz="2.03575203952619E-10" />
    </inertial>
    <visual>
      <origin
        xyz="0 0 0"
        rpy="0 0 0" />
      <geometry>
        <mesh
          filename="package://neor_mini/meshes/front_steer_link.STL" />
      </geometry>
      <material
        name="">
        <color
          rgba="0.274509803921569 1 0.247058823529412 1" />
      </material>
    </visual>
    <collision>
      <origin
        xyz="0 0 0"
        rpy="0 0 0" />
      <geometry>
        <mesh
          filename="package://neor_mini/meshes/front_steer_link.STL" />
      </geometry>
    </collision>
  </link>
  <joint
    name="front_steer_joint"
    type="revolute">
    <origin
      xyz="0.172883370897628 0 -0.00376561854722868"
      rpy="0 0 0" />
    <parent
      link="base_link" />
    <child
      link="front_steer_link" />
    <axis
      xyz="0 0 1" />
    <limit
      lower="-0.72"
      upper="0.72"
      effort="0"
      velocity="0" />
  </joint>

<!-- In order to fit ackermann simulation plugins's request,amend the front steer link and it's joint -->
 <link name="front_steer_right_link">
 <!--  remember add inertial  label,if not,and it can't visual on gazebo-->
 <inertial>  
      <origin xyz="9.44636555644252E-08 -0.000295273745285485 -8.13046296954667E-11" rpy="0 0 0" />
      <mass value="0.296315811300368" /> 
      <inertia
        ixx="0.000374692013709393"
        ixy="-9.17172260383823E-08"
        ixz="-2.43187512356516E-12"
        iyy="0.000661029987747155"
        iyz="1.9736939507106E-13"
        izz="0.000374691963930348" />
    </inertial>
   <visual>
     <geometry>
       <cylinder length="0.001" radius="0.005"/>
     </geometry>
     <origin rpy="0 0 0"  xyz="0 0 0" />
     <material name=""> 
          <color rgba="0.792156862745098 0.819607843137255 0.933333333333333 1" />
     </material>
   </visual>
   <collision>
      <origin
        xyz="0 0 0"
        rpy="0 0 0" />
      <geometry>
       <cylinder length="0.001" radius="0.005"/>
      </geometry>
    </collision>
 </link>
 <joint name="front_steer_right_joint" type="revolute">
    <origin rpy="0 0 0"  xyz="0.17 -0.21 0.102" />
    <parent link="base_link" />
    <child link="front_steer_right_link" />
    <axis xyz="0 0 1" />     <!-- charge steer direction default is 0 0 1-->
    <limit lower="-0.69" upper="0.69" effort="0" velocity="0" />
 </joint>
<!-- ************************************************************************************* -->

  <link
    name="front_right_wheel_link">
    <inertial>
      <origin
        xyz="9.44636555644252E-08 -0.000295273745285485 -8.13046296954667E-11"
        rpy="0 0 0" />
      <mass
        value="0.296315811300368" />
      <inertia
        ixx="0.000374692013709393"
        ixy="-9.17172260383823E-08"
        ixz="-2.43187512356516E-12"
        iyy="0.000661029987747155"
        iyz="1.9736939507106E-13"
        izz="0.000374691963930348" />
    </inertial>
    <visual>
      <origin
        xyz="0 0 0"
        rpy="0 0 0" />
      <geometry>
        <mesh
          filename="package://neor_mini/meshes/front_right_wheel_link.STL" />
      </geometry>
      <material
        name="">
        <color
          rgba="0.792156862745098 0.819607843137255 0.933333333333333 1" />
      </material>
    </visual>
    <collision>
      <origin
        xyz="0 0 0"
        rpy="0 0 0" />
      <geometry>
        <mesh
          filename="package://neor_mini/meshes/front_right_wheel_link.STL" />
      </geometry>
    </collision>
  </link>
  <joint name="front_right_wheel_joint" type="continuous">
    <origin xyz="0 0 -0.06" rpy="0 0 0" />   <!-- amend the position between steer_right_link and front right wheel-->
    <parent link="front_steer_right_link" />
    <child  link="front_right_wheel_link" />
    <axis xyz="0 1 0" />
  </joint>

<!-- In order to fit ackermann simulation plugins's request,amend the front steer link and it's joint -->
 <link name="front_steer_left_link">
 <!--  remember add inertial  label,if not,and it can't visual on gazebo-->
    <inertial> 
      <origin xyz="9.44636555644252E-08 -0.000295273745285485 -8.13046296954667E-11" rpy="0 0 0" />
      <mass value="0.296315811300368" /> 
      <inertia
        ixx="0.000374692013709393"
        ixy="-9.17172260383823E-08"
        ixz="-2.43187512356516E-12"
        iyy="0.000661029987747155"
        iyz="1.9736939507106E-13"
        izz="0.000374691963930348" />
    </inertial>
   <visual>
     <geometry>
       <cylinder length="0.001" radius="0.005"/>
     </geometry>
     <origin rpy="0 0 0"  xyz="0 0 0" />
   </visual>
    <collision>
      <origin xyz="0 0 0" rpy="0 0 0" />
      <geometry>
       <cylinder length="0.001" radius="0.005"/>
      </geometry>
    </collision>
 </link>
 <joint name="front_steer_left_joint" type="revolute">
    <origin rpy="0 0 0"  xyz="0.17 0.21 0.102" />
    <parent link="base_link" />
    <child link="front_steer_left_link" />
    <axis xyz="0 0 1" />  <!-- charge steer direction default is 0 0 1-->
    <limit lower="-0.69" upper="0.69" effort="0" velocity="0" />
 </joint>
<!-- ************************************************************************************* -->

  <link
    name="front_left_wheel_link">
    <inertial>
      <origin
        xyz="-3.99413835339146E-11 0.000295273997845347 1.08602016268833E-10"
        rpy="0 0 0" />
      <mass
        value="0.296315811293944" />
      <inertia
        ixx="0.00037469197851121"
        ixy="-1.84493877596723E-13"
        ixz="-9.50756757097929E-12"
        iyy="0.00066103001709398"
        iyz="-1.17866882205563E-13"
        izz="0.000374691969713977" />
    </inertial>
    <visual>
      <origin
        xyz="0 0 0"
        rpy="0 0 0" />
      <geometry>
        <mesh
          filename="package://neor_mini/meshes/front_left_wheel_link.STL" />
      </geometry>
      <material
        name="">
        <color
          rgba="0.792156862745098 0.819607843137255 0.933333333333333 1" />
      </material>
    </visual>
    <collision>
      <origin
        xyz="0 0 0"
        rpy="0 0 0" />
      <geometry>
        <mesh
          filename="package://neor_mini/meshes/front_left_wheel_link.STL" />
      </geometry>
    </collision>
  </link>
  <joint name="front_left_wheel_joint" type="continuous">
    <origin xyz="0 0 -0.06" rpy="0 0 0" />      <!-- amend the position between steer_left_link and front left wheel-->
    <parent link="front_steer_left_link" />
    <child link="front_left_wheel_link" />
    <axis xyz="0 1 0" /> 
  </joint>


</robot>

launch文件

<launch>
  <param name="robot_description" textfile="$(find neor_mini)/urdf/neor_mini.urdf" />
  <node name="joint_state_publisher_gui" pkg="joint_state_publisher_gui" type="joint_state_publisher_gui" />
  <node name="robot_state_publisher" pkg="robot_state_publisher" type="robot_state_publisher" />
  <node name="rviz" pkg="rviz" type="rviz" args="-d $(find neor_mini)/rviz/neor_mini_rviz.rviz" />
</launch>