No such file or directory: /opt/ros/melodic/share/franka_description/robots/panda_arm_hand.urdf.xacr

刚开始学习moveit，按照MoveIt Quickstart in RViz — moveit_tutorials Kinetic documentatione

的教程学习，但是在运行到

roslaunch panda_moveit_config demo.launch rviz_tutorial:=true

报错

No such file or directory: /opt/ros/melodic/share/franka_description/robots/panda_arm_hand.urdf.xacro [Errno 2] No such file or directory: '/opt/ros/melodic/share/franka_description/robots/panda_arm_hand.urdf.xacro'
RLException: while processing /home/arl/ws_moveit/src/panda_moveit_config/launch/planning_context.launch:
Invalid  tag: Cannot load command parameter [robot_description]: command [['/opt/ros/melodic/lib/xacro/xacro', '/opt/ros/melodic/share/franka_description/robots/panda_arm_hand.urdf.xacro']] returned with code [2]. 

Param xml is 
The traceback for the exception was written to the log file

答案是没有在src文件中添加franka的描述文件description

首先将描述文件放在src中，然后

rosrun moveit_setup_assistant moveit_setup_assistant

进行franka机械臂的配置

之后

source devel/setup.bash
roslaunch panda_moveit_config demo.launch

 就可以在moveit中进行规划了