PGP mode

[BIRL-xu]

Hi, I want to try the PGP mode specified in the readme--"If a smooth path is provided, the controller has the option to track the path with the base_link directly instead of lagging behind a carrot." I have two questions about that:

1. How to configure this mode?
2. What's the smooth path(I mean that distance between points and curvature or something else ), and how to input it to the controller?

Thank you very much!~