Autolabor pro1 xacro Simulation Error

[SimonCK666]

Dear kinglintianxia,

You did a very nice project. But I found some bugs when I ran.

My Device,
Ubuntu 20.04
ROS Noetic

I followed all your previews steps until Robot Sim

When I ran command roslaunch autolabor_pro1_description auto_pro1_laser_view.launch
I got error below

... logging to /home/simon/.ros/log/251ad4d4-b5c3-11ec-ac5b-ff0e2900c350/roslaunch-simon-9616.log
Checking log directory for disk usage. This may take a while.
Press Ctrl-C to interrupt
Done checking log file disk usage. Usage is <1GB.

xacro: in-order processing became default in ROS Melodic. You can drop the option.
name 'parent' is not defined
when evaluating expression 'parent'
when processing file: /home/simon/auto_ws/src/autolabor_pro1/autolabor_pro1_description/urdf/auto_pro1/wheel.urdf.xacro
included from: /home/simon/auto_ws/src/autolabor_pro1/autolabor_pro1_description/urdf/auto_pro1/base.urdf.xacro
included from: /home/simon/auto_ws/src/autolabor_pro1/autolabor_pro1_description/urdf/auto_pro1/auto_pro1_with_laser.xacro
RLException: Invalid <param> tag: Cannot load command parameter [robot_description]: command [['/opt/ros/noetic/lib/xacro/xacro', '--inorder', '/home/simon/auto_ws/src/autolabor_pro1/autolabor_pro1_description/urdf/auto_pro1/auto_pro1_with_laser.xacro']] returned with code [2].

Param xml is <param name="robot_description" command="$(arg urdf_file)"/>
The traceback for the exception was written to the log file

Maybe the error happened at file wheel.urdf.xacro that contains ${parent}

 <joint name="${parent}_${suffix}_wheel_joint" type="continuous">