Showing papers by "Nils J. Nilsson published in 1972"
TL;DR: The paper on the use of heuristic information in graph searching defined a path-finding algorithm, A*, and proved that it had two important properties; it was proved that if the heuristic function ñ (n) is a lower bound on the true minimal cost from node n to a goal node, then A* is admissible; i.e., it would find a minimal cost path if any path to agoal node existed.
Abstract: Our paper on the use of heuristic information in graph searching defined a path-finding algorithm, A*, and proved that it had two important properties. In the notation of the paper, we proved that if the heuristic function n (n) is a lower bound on the true minimal cost from node n to a goal node, then A* is admissible; i.e., it would find a minimal cost path if any path to a goal node existed. Further, we proved that if the heuristic function also satisfied something called the consistency assumption, then A* was optimal; i.e., it expanded no more nodes than any other admissible algorithm A no more informed than A*. These results were summarized in a book by one of us.
334 citations
01 Aug 1972
TL;DR: This paper describes a variety of ways in which traditional constraints on robot problem-solving methods could be relaxed, illustrating the discussion where possible with examples taken from the current Stanford Research Institute robot system.
Abstract: : For the past several years research on robot problem-solving methods has centered on what may one day be called simple plans: linear sequences of actions to be performed by single robots to achieve single goals in static environments. Recent speculation and preliminary work at several research centers has suggested a variety of ways in which these traditional constraints could be relaxed. In this paper we describe some of these possible extensions, illustrating the discussion where possible with examples taken from the current Stanford Research Institute robot system.
66 citations