cupoch | Robotics with GPU | Robotics library

I have limited experience in drake and currently trying to learn and implement some simple algorithms. The code I have is based on an example from the Underactuated Robotics course by R. Tedrake. The code is a slightly modified version of this example here, where the goal is to design a Lyapanuv Control Function for the unicycle robot model.

To simulate the robot model, an instance of SymbolicVectorSystem from drake is used.

As I understand this is just a building block for the "prototyping" and designing a suitable controller, is this correct?, is SymbolicVectorSystem still needed if there is a real robot?.

Now that I am happy with the controller, I would like to deploy this controller to a ROS2 robot. For that, I have written a simple script that subscribes to the current robot states from the localization system that I have. I am not really sure how to proceed from here, I think I need to connect the received robot state messages to the input of the controller, then publish the output of the controller back to the robot. The problem is I couldn't find any examples that suit this use case.

An approach I think of, could be that I create another class that inherits from VectorSystem, and this class wraps the ros stuff to subscribe publish ROS messages. In overridden DoCalcVectorOutput function of my wrapper class, I assign/retrieve the I/O and publish retrieved control commands. Finally, I connect the I/O of controller and wrapper classes with a DiagramBuilder

I am not sure if this will work, or if this is will be the recommended approach, I will appreciate your help.

Here is what the current code looks like;