I would like to know what is the algorithm that divides recognized objects into these sets {trash bag, tin can, squirrel, leaves, small branch, frisbee, small

I would like to know what is the algorithm that divides recognized objects into these sets {trash bag, tin can, squirrel, leaves, small branch, frisbee, small stone, snow drift, speed bump, ...} and {deer, jogger, bicycle, basketball, curled tread from trailer of 18-wheeler, rock fall, a door (that fell from a truck), a toppled traffic cone, tree trunk, armadillo, crevasse, ...} I'm sure I'm just scratching the surface, of items that a) should just get run-over, and b) should be avoided or emergency stopped.