Tutorial code referenced in https://docs.nav2.org/plugin_tutorials/docs/writing_new_nav2controller_plugin.html

This controller implements a the pure pursuit algorithm to track a path.

The global path is continuously pruned to the closest point to the robot (see the figure below). Then the path is transformed to the robot frame and a lookahead point is determined. This lookahead point will be given to the pure pursuite algorithm to calculate a command velocity.