Thanks for your code,I want to ask how it actually works?

[luoyuzju]

I have downloaded the local planner,and modify some error,finally catkin_make successfully.and in my simulation ,it makes my car move.but it can't avoid the obstacle.More concretely,when i set the goal point behind the obstacle,it just moves straight even though it touch the obstacle! it's strange,so i want to ask how this algorithm actually works?
I'm sorry that it may bother you. Thank you!