What's the importance of defining .machine file?
I'm working on pr2_arm_navigation and there is a launch file that includes another launch file "right_arm_collision_free_ik.launch." In the launch file there is a line as follow:
<include file="$(find pr2_machine)/$(env ROBOT).machine" />
I would like to know what the .machine file is used for. Is that related to command such as "export ROBOT=sim", which is for the purpose of discrimination of a real physical world Robot and a simulation Robot?
Appreciate for any help.