Function of local_planner smoothing_margin_degrees

Hello everybody,

it’s not clear to me, what exactly the function/use of the smoothing_margin_degrees control parameter of the local planner is. In the code it states: “smoothing radius for obstacle cost in cost histogram”. However, I still don’t get the actual function of it. How can an angle (degrees) be a radius? And why do obstacle cost need a radius at all in the histogram? Is the obstacle cost of a certain point in the histogram changing over time? Is the size (occupancy of cells in the histogram) of the obstacle changing over time?

Thank you very much