The Nav2 Controller is an Execution Module that implements the nav2_msgs::action::FollowPath action server.
An execution module implementing the nav2_msgs::action::FollowPath action server is responsible for generating command velocities for the robot, given the computed path from the planner module in nav2_planner. The nav2_controller package is designed to be loaded with plugins for path execution. The plugins need to implement functions in the virtual base class defined in the controller header file in nav2_core package.
Currently available controller plugins are: DWB, and TEB (dashing release).