# how to find space in point cloud larger than given l*b

Is their any method by using which I can find a space or gap in given point cloud which has size greater than given rectangle of size $$l*b$$ or a circle of radius $$r$$? This way my robot can make a path to that space and move towards it. Is this possible by first finding the key points than applying triangular to given key points?

I am developing a navigation algorithm for my robot, and wondering if this kind of method already exists.