
Lab Papers (GRASP)
Document Type
Conference Paper
Date of this Version
7-11-2009
Abstract
We study path planning on grids with blocked and unblocked cells. Any-angle path-planning algorithms find short paths fast because they propagate information along grid edges without constraining the resulting paths to grid edges. Incremental path-planning algorithms solve a series of similar path-planning problems faster than repeated single-shot searches because they reuse information from the previous search to speed up the next one. In this paper, we combine these ideas by making the any-angle path-planning algorithm Basic Theta* incremental. This is non-trivial because Basic Theta* does not fit the standard assumption that the parent of a vertex in the search tree must also be its neighbor. We present Incremental Phi* and show experimentally that it can speed up Basic Theta* by about one order of magnitude for path planning with the freespace assumption.
Date Posted: 01 October 2009

Comments
A. Nash, S. Koenig and M. Likhachev. Incremental Phi*: Incremental Any-Angle Path Planning on Grids. In Proceedings of the International Joint Conference on Artificial Intelligence (IJCAI), pages (in print), 2009.