ROS报错：joint-state-publisher报错

[WARN] [1664518996.207303]: The 'use_gui' parameter was specified, which is deprecated.  We'll attempt to find and run the GUI, but if this fails you should install the 'joint_state_publisher_gui' package instead and run that.  This backwards compatibility option will be removed in Noetic.
[ERROR] [1664518996.208012]: Could not find the GUI, install the 'joint_state_publisher_gui' package
[joint_state_publisher-2] process has died [pid 45929, exit code 1, cmd /opt/ros/melodic/lib/joint_state_publisher/joint_state_publisher __name:=joint_state_publisher __log:=/home/rosmelodic/.ros/log/5db3fa96-4088-11ed-89d6-000c2969e545/joint_state_publisher-2.log].
log file: /home/rosmelodic/.ros/log/5db3fa96-4088-11ed-89d6-000c2969e545/joint_state_publisher-2*.log

问题出现原因：

找到想要打开的launch文件，里面用到了一个关节状态的一个发布者。

roslaunch xarm_description xarm7_rviz_display.launch

这条命令打开的是一个演示文件，常常用来在moveit配置助手配置完一个机械臂后，进行检查看配置的正确性。

出现关节空间发布者问题，关节空间状态会出错，其中图中标识处会标红。

 确定完问题，开始解决。

"1.0"?>
<launch>
 
  
 
  <arg name="limited" default="True" doc="If true, limits joint range (-PI, PI) on all joints." />
  <arg name="add_gripper" default="false" doc="If true, will load xarm5 with gripper from UFACTORY attached." />
  <arg name="joint_state_source" default="[/joint_states]" />
  <arg name="joint_state_publisher_gui" default="true" />
 
  <include file="$(find xarm_description)/launch/xarm7_upload.launch" >
    <arg name="limited" value="$(arg limited)"/>
    <arg name="add_gripper" value="$(arg add_gripper)" />
  include>
 
  <node name="joint_state_publisher_gui" pkg="joint_state_publisher_gui" type="joint_state_publisher_gui">
    <param name="use_gui" value="$(arg joint_state_publisher_gui)"/>
    <rosparam param="source_list" subst_value="True">$(arg joint_state_source)rosparam>
  node>
  <node name="robot_state_publisher" pkg="robot_state_publisher" type="robot_state_publisher" />
 
  <arg name="config" default="true" />
  <arg unless="$(arg config)" name="command_args" value="" />
  <arg     if="$(arg config)" name="command_args" value="-d $(find xarm_description)/launch/display.rviz" />
  
  <node name="rviz" pkg="rviz" type="rviz" args="$(arg command_args)" output="screen"/>
launch>

解决：在这个位置，moveit！自动生成的一般都会出现这个问题，没有_gui，将其填上。

  <node name="joint_state_publisher_gui" pkg="joint_state_publisher_gui" type="joint_state_publisher_gui">

再次运行，仍会报错。

ERROR: cannot launch node of type [joint_state_publisher_gui/joint_state_publisher_gui]: joint_state_publisher_gui
ROS path [0]=/opt/ros/melodic/share/ros
ROS path [1]=/home/rosmelodic/catkin_ws/src
ROS path [2]=/opt/ros/melodic/share

出现无法启动这个类型的节点，同时下面给出了ros_melodic根目录的路径。

解决：安装需要的插件。

sudo apt-get install ros-melodic-joint-state-publisher-gui

再次运行。

右侧为可以控制关节空间状态的插件，左侧是rviz在展示（display）机械臂，也正是这个launch文件的功能 。