ROS建立机器人模型，小车还没添加雷达的时候能显示车轮，添加了雷达就不能显示车轮了，怎么回事？

Question

报错信息

```xml
[joint_state_publisher_gui-4] process has died [pid 12032, exit code 1, cmd /opt/ros/melodic/lib/joint_state_publisher_gui/joint_state_publisher_gui __name:=joint_state_publisher_gui __log:=/home/milk/.ros/log/42928814-cdcd-11ec-8a0c-94b86d736de2/joint_state_publisher_gui-4.log].
log file: /home/milk/.ros/log/42928814-cdcd-11ec-8a0c-94b86d736de2/joint_state_publisher_gui-4*.log

car.launch

<launch>
    <param name="robot_description" command="$(find xacro)/xacro $(find urdf01_rviz)/urdf/xacro/car.urdf.xacro" />

    <node pkg="rviz" type="rviz" name="rviz" args="-d $(find urdf01_rviz)/config/show_mycar.rviz" />
    <node pkg="joint_state_publisher" type="joint_state_publisher" name="joint_state_publisher" output="screen" />
    <node pkg="robot_state_publisher" type="robot_state_publisher" name="robot_state_publisher" output="screen" />
    <node pkg="joint_state_publisher_gui" type="joint_state_publisher_gui" name="joint_state_publisher_gui" output="screen" />

</launch>

![img](https://img-mid.csdnimg.cn/release/static/image/mid/ask/51725460915614.png "#left")

![img](https://img-mid.csdnimg.cn/release/static/image/mid/ask/841205609156195.png "#left")