Minimax real-time heuristic search

Abstract

Real-time heuristic search methods interleave planning and plan executions and plan only in the part of the domain around the current state of the agents. So far, real-time heuristic search methods have mostly been applied to deterministic planning tasks. In this article, we argue that real-time heuristic search methods can efficiently solve nondeterministic planning tasks. We introduce Min-Max Learning Real-Time A∗ (Min-Max LRTA∗), a real-time heuristic search method that generalizes Korf's LRTA∗ to nondeterministic domains, and apply it to robot-navigation tasks in mazes, where the robots know the maze but do not know their initial position and orientation (pose). These planning tasks can be modeled as planning tasks in nondeterministic domains whose states are sets of poses. We show that Min-Max LRTA∗ solves the robot-navigation tasks fast, converges quickly, and requires only a small amount of memory.